VOLUME S, Number 12 $2.00 in USA $2.40 in CANADA

xpECEMBER19743 VOLUME S, Number 12

$2.00 in USA $2.40 in CANADA Someday all terminals will be smart......

128 Functions -software controlled 82 x 16 or 92 x 22 format -plus graphics 7 x 12 matrix, upper /lower case letters Printer output port 50 to 38,400 baud - selectable "CHERRY" keyboard

CT -82 Intelligent Terminal, assembled and tested S795.00 ppd in Cont. U.S.

SOUTHWEST TECHNICAL PRODUCTS CORPORATION 219 W. RHAPSODY SAN ANTONIO, TEXAS 78216

Circle 350 on inquiry card. RS-232 or Parallel Parallel Parallel Current Loop I/O Port #1 I/O Port #2 I/O Port #3 I/O Port #4

Latched Outputs Programmable Baud Rate UART with Interval Timers

4 MHz 4 MHz Z80A Crystal Clock

Completely Buffered Bus Interface On Card Voltage Regulation tt Irl Standard Bus 8K ROM 1K RAM for System Capacity Expandability The single card computer with the features that help you in real life

COMPLETE COMPUTER ENORMOUS EXPANDABILITY EASY TO USE In this advanced card you get a pro- Besides all these features the Cro- Another convenience that makes the fessional quality computer that meets memco single card computer gives you Model SCC computer easy to use is our today's engineering needs. And it's one enormous expandability if you ever need Z -80 monitor and 3K Control BASIC (in that's complete. It lets you be up and it. And it's easy to expand. First, you two ROMs). With this optional software running fast. All you need is a power can expand with the new Cromemco you're ready to go. The monitor gives supply and your ROM software. 32K BYTESAVER PROM card mentioned you 12 commands. The BASIC, with 36 The computer itself is super. Fast above. Then there's Cromemco's broad commands /functions, will directly ac- 4 MHz operation. Capacity for 8K bytes line of S100- bus -compatible memory cess I/O ports and memory locations - of ROM (uses 2716 PROMs which can and I/O interface cards. Cards with fea- and call machine language subroutines. be programmed by our new 32K BYTE - tures such as relay interface, analog Finally, to simplify things to the ulti- SAVERS PROM card). There's also 1K of interface, graphics interface, opto- mate, we even have convenient card on -board static RAM. Further, you get isolator input, and A/D and D/A con- cages. Rugged card cages. They hold straightforward interfacing through an version. RAM and ROM cards, too. cards firmly. No jiggling out of sockets. RS -232 serial interface with ultra -fast speed of up to 76,800 baud - software AVAILABLE NOW /LOW PRICE programmable. The Cromemco Model SCC is avail- Other features include 24 bits of bi- able now at a low price of only $450 directional parallel I/O and five on- factory assembled ($395 kit). board programmable timers. So act today. Get this high -capability Add to that vectored interrupts. computer working for you right away. 32K BYTESAVER PROM card Cromemco Gin c or p or a t e d Specialists in computers and peripherals 280 BERNARDO AVE., MOUNTAIN VIEW, CA 94040 (415) 964 -7400

Circle 80 on inquiry card. BYTE December 1978 1 Z-ZD

(.umf,urrO)srnrt_. -

RI Crwrnee

Model Z -2D System Two Model Z-2 One or two disks Dual disk Up to 512K of RAM /ROM Up to 5121( of RAM /ROM Up to 512K of RAM /ROM Up to 184K of disk Up to 184K of disk Fill your computer needs with the industry's most professional microcomputers

#1 IN RELIABILITY Up to 512 kilobytes of RAM and Cromemco card support of more a for 1 megabyte of disk storage than dozen circuit cards When you choose Cromemco you process control, business sys- get not only the industry's finest tems, and data acquisition in- microcomputers but also the indus- / cluding cards for A -D and D -A try's widest microcomputer selec- conversion, for interfacing daisy- tion. wheel or dot -matrix printers, even What's more, you get a computer a card for programming PROMs. from the manufacturer that compu- The industry's most professional ter dealers rate #1 in product re- software support, including liability.' COBOL, FORTRAN IV, 16K Disk - Your range of choice includes Extended BASIC, Z -80 Macro our advanced System Three with r; Assembler, Cromemco Multi - up to four 8" disk drives. Or choose User Operating System, Data from the System Two and Z -2D with System Three Base Management System, Word 5" drives. Then for ROM -based work Two to four disks Up to 512K of RAM /ROM Processing System - and more there's the Z2. Each of these com- Up to 1 megabyte of disk coming. puters further offers up to 1/2 mega- Rugged, professional all -metal byte of RAM (or ROM). 30 -amp power supply - more construction for rack (or bench We say these are the industry's than adequate for your most or floor cabinet) mounting. Cab- most professional microcomputers demanding application. inets available. because they have outstanding fea- 21 card slots to allow for un- tures like these: paralleled system expansion us- FOR TODAY AND TOMORROW ing industry- standard S -100 Z -80A microprocessor oper- Cromemco computers will meet - cards. ates at 250 nano second cycle your needs now and in the future time - nearly twice the speed of S -100 bus - don't overlook how because of their unquestioned tech- most others. important this is. It has the in- nical leadership, professionalism dustry's widest support and Cro- and enormous expandability. 'Rated in The 1977 Computer Store memco has professionally imple- See them today at your dealer. Survey by Image Resources, Westlake mented it in a fully -shielded There's no substitute for getting Village, CA. design. the best. Cromemco in c o r p or a t e d Specialists in computers and peripherals 280 BERNARDO AVE., MOUNTAIN VIEW, CA 94040 (415) 964 -7400 2 BYTE December 1978 0 Circle 80 on inquiry card. r In the Queue EIVTE December 1978 Volume 3 Number 12

PUBLISHERS Foreground Virginia Londoner Gordon R Williamson 14 DIRECTOR, EDITORIAL PLANNING FAST FOURIER TRANSFORMS ON YOUR HOME COMPUTER Carl T Hdmers Ir Software -Stanley- Peterson EDITOR IN CHIEF Christopher P Morgan 26 DESIGNING A UNIVERSAL TURING MACHINE: A Software Approach VICE-PRESIDENT, PRODUCTION Software -Munnecke Iudith Havey PRODUCTION MANAGER 32 BUILD AN OCTAL /HEXADECIMAL OUTPUT DISPLAY Karen Gregory Hardware - Ciarcia ADVE RTIS ING DIRECTOR john Hayes 94 INTERFACE YOUR COMPUTER TO A PRINTING CALCULATOR CIRCULATION MANAGER Hardware Gregory Spitafaden -Astmann COMMUNICATIONS COORDINATOR 100 ZAPPER: A Computer Driven EROM Programmer James C Morrissett, K6MH EDITORS Hardware -Gable Raymond G A Cote 128 CLOCKLESS MULTIPLICATION AND DIVISION CIRCUITS Blaire W Liffick Richard Shuford Hardware -Weed PRODUCTION EDITORS 140 CREATING A CHESS PLAYER, Part 3: Chess 0.5 (continued) Nancy Salmon David William Hayward Computer Chess Software -Frey -Atkin Peter Perin 168 PARTITIONED DATA SETS PRODUCTION ASSISTANT Cheryl A Hurd Tutorial- Halsema PRODUCTION ART Stephen Kruse Wai Chia Li Dorothy Shamonsky Background Ellen Shamonsky NEW PRODUCTS EDITOR CLUBS, NEWSLETTERS 45 LIFE WITH YOUR COMPUTER Laura A Hanson Applications: Life Games -Milliun-Reardon -Smart ASSISTANT ADVERTISING DIRECTOR Patricia Clark 54 SOME FACTS OF LIFE ADVERTISING PRODUCTION COORDINATOR L ife- Buckingham Thomas Harvey ADVERTISING ASSISTANTS 68 ONE -DIMENSIONAL LIFE Noreen Bardslry Life Games -Millen lilt Callihan COMPTROLLER 84 CHESS 4.7 VERSUS DAVID LEVY Kevin Maguire Computer Chess -Douglas ASSISTANT TO COMPTROLLER Mary Steiner 108 AN EASY PROGRAMMING SYSTEM ASSISTANT TO PUBLISHERS Software Weisbecker Ruth M Walsh - EDITORIAL ASSISTANT 124 TEACHING WITH A MICROCOMPUTER Gale Britton Applications -Ger hol d CIRCULATION ASSISTANTS Christine Dixon 186 THE MOTHER CHIP Ann Graves Fiction - Willard Pamela R Heaslip Agnes E Perry 194 FORTRAN AND ITS GENERALIZATIONS DEALER SALES Language Ginnie F Boudrieau Tutorial- Maurer Anne M Baldwin TRAFFIC MANAGER Rick Fuette RECEPTIONIST Nucleus Jacqueline Earnshaw DRAFTING 4 In This BYTE Tertian Associates TYPOGRAPHY 6 New Wonders of the Computer Age Goodway Graphics 10 Letters PHOTOGRAPHY Ed Crabtree 43 Book Reviews PRINTING Programming Quickies: The George Banta Company 76 Life ASSOCIATE EDITOR 92 Nybbles: Z -80 Assembler Daniel Fylstra ASSOCIATES 161, 163 BYTE's Bits, BYTE's Bugs Walter Banks 164 Event Queue Steve Garcia David Fylstra 166 Clubs, Newsletters Portia Isaacson 174 Programming Quickies: Tic -Tac -Toe in BASIC BOOK DIVISION: PRODUCTION MANAGER 176 Languages Forum Edmond C Kelly Ir 184, 202, 208 Technical Forum PRODUCTION ASSISTANT Patricia Curran 192 Desk Top Wonders: A Game for the TI -58 NATIONAL ADVERTISING 209 What's New? SALES REPRESENTATIVES: Hajar Associates Inc 246 Unclassified Ads EAST 248 BOMB, Reader Service 280 Hillside Av Needham Heights MA 02194 (617)444.3946 MIDWEST BYTE is published monthly by BYTE Publications Inc, 70 Main St, Peterborough NH 03458. Address all mailexcept sub- 664 N Michigan Av scriptions to above address: phone (6031 924-7217. Address all editorial correspondence to the editor at the above address. Chicago IL 60611 Unacceptable manuscripts will be returned if accompanied by sufficient first class postage. Not responsible for lost manu- (312) 337 -8008 scripts or photos. Opinions expressed by the authors are not necessarily those of BYTE. Address all subscriptions, change of WEST, SOUTHWEST address, Form 3579, and fulfillment complaints to BYTE Subscriptions, PO Box 590, Martinsville NJ 08836. Second class 1000 El Wdle Ct Suite 227 postage paid at Peterborough NH 03458 and at additional mailing offices -USPS Publication No. 102410. Canadian second Palo Alto CA 94303 class registration No. 9321. Subscriptions are $15 for one year, $27 for two years, and $39 for three years in the USA and its (415) 9640706 possessions. In Canada and Mexico, 517.50 for one year, $32 for two years, and $46.50 for three years. $25 for a one year DISTRIBUTORS: subscription by surface mail worldwide. Air delivery to selected areas at additional rates available upon request. $25 for a one EASTERN CANADA year subscription by air delivery to Europe. Single copy price is $2.00 in the USA and its possessions, $2.40 in Canada and RS -232 Distribution Company Mexico, $3.50 in Europe, and $4.00 elsewhere. Foreign subscriptions and sales should be remitted in United States funds. 186 Queen St W, Suite 232 Toronto ONTARIO Printed in United States of America. Each separate contribution to this issue and the issue as a collective work copyright © WESTERN CANADA 1978 by BYTE Publication Inc. All rights reserved. Kittonic Ltd 26236 26th Av RR 5 Subscription WATS Line: (800) 258 -5485 Aldergrove BC VOX 1A0 a'

December 1978 © BYTE Publications Inc 3 The advent of the personal com- proved version, Chess 4.7. Read the should possess in Teaching with a puter has made possible the calcula- story of the epic battle of the mighty Microcomputer. page 124 tion of the fast Fourier transform computer and the tenacious, clever (FFT) on the small system. Appli- human chess master in an article by If you have a need for multiplica- cations of this powerful design tool J R Douglas, Chess 4.7 versus David tion and division circuits and don't include speech and music analysis as Levy. page 84 want to worry about timing diagrams, well as circuit design and development. read Mike Weed's discussion of some Read Fast Fourier Transforms on In many microcomputer applica- Clockless Multiplication and Division Your Home Computer by William D tions it is desirable to have a cheap Circuits you can work with. page 128

Stanley and Steven J Peterson. method for printing numerical data. page 14 Robert H Astmann describes a This month we present the second way to interface a Texas Instru- half of Chess 0.5 in the series Creating Quite often a software approach to ments 5050M printing calculator to a Chess Player by Peter W Frey and a problem is easier to implement than an 8080A based computer in Inter- Larry R Atkin. The program was a hardware approach to the same face Your Computer to a Printing written by Larry Atkin, who is co- problem. Tom Munnecke describes the Calculator. page 94 author with David Slate of the world software used in Designing a Universal championship computer chess pro- Turing Machine and compares it to a gram, Chess 4.6. The program is comparable hardware approach. written in Pascal and is readily adapta- page 26 ble to personal computers having In This GUTE Pascal systems such as the UCSD Steve Ciarcia describes a simple but Pascal project software. page 140 useful addition to your computer in Build an Octal /Hexadecimal Output To get the most out of your floppy Display. This circuit can help you to When building a computer system it disk units, you should know how to convert from octal to hexadecimal is frequently advisable to have your handle the data that will be stored on

(and vice versa) or give you the status most often used basic routines stored them efficiently. A I Halsema intro- of a byte during program execution. in read only memory so that they will duces us to the concept of Partitioned page 32 always be readily available. To make Data Sets and briefly describes a the best use of read only memory, the method for implementing them. Our cover theme this month experimenter should be able to pro- page 168 (painted by Robert Tinney) is the gram his own. G H Gable describes game of Life. In Life with Your one system for programming read only What is the world going to be like Computer, Justin Milliun, Judy memory in his article, Zapper: A Com- in twenty years? That's a difficult Reardon and Peter Smart give a puter Driven EROM Programmer. question to answer, but the chances starting point for developing your own page 100 are that microcomputers will be part version of this exciting game. page 45 of it. Lawrence Willard takes a light- Are you having trouble affording hearted look at one possible future in Researchers probing cellular auto- enough hardware to support a high h is story, The Mother Chip. page 186 mata have used Conway's game of Life level language such as BASIC? Are you as a tool in creating a collection of finding it difficult to program in your FORTRAN is one of the ante- strange and exciting patterns. In David machine's assembler language? If your cedents to a number of computer Buckingham's article Some Facts of answer to either of those questions is languages. The ever popular BASIC is Life we find a description of dis- "yes," then what you're looking for in some respects a simplification of coveries made since the original flurry is An Easy Programming System. In FORTRAN. A number of later lan- of activity several years ago. page 54 this article, Joe Weisbecker gives an guages build upon the computer introduction to hexadecimal interpre- science learning experience which was One -Dimensional Life is an intrigu- tive programming, an alternative to FORTRAN and its compilers in the ing variant on John Conway's famous high level languages and assemblers late 1950s and early 1960s. FOR- game. Out of this restricted format alike. page 108 TRAN is even now becoming available comes a surprising variety of familiar in floppy disk based systems at the Life figures such as the flip flop and Computer aided instruction is an high end of the personal computing glider. Dr Jonathan K Millen leads us excellent microcomputer application. performance range. In this issue, down the Life line in One -Dimensional To perform this function correctly, W Douglas Maurer provides readers Life. page 68 it helps to have a programming lan- with an article on FORTRAN and Its guage designed for the purpose. Generalizations, good background The same folks who brought you Prof George A Gerhold describes reading on an important and still much Chess 4.6 now bring you a new, im- some of the features such a language used language. page 194

4 December 1978 © BYTE Publications Inc New from North Star Double Density Performance at Single Density Prices ,:, . The new HORIZON computer and density, so existing single density disk- Micro Disk System now record in dou- ettes can still be used. Single density ble density! That means each new SA -400 drives previously purchased Shugart SA -400 minifloppy disk drive with North Star systems can also be accesses 180K bytes of on -line infor- used. mation. All double density HORIZON Pricing computers and Micro Disk Systems Specifications: HORIZON with one double density have a redesigned controller which S -100 compatible. MFM SA -400 minifloppy (180K bytes), 16K encoding, 35 tracks with ten allows the use of quadruple capacity RAM, Z80A processor and serial 110 512 -byte sectors per track. disk drives as they become available in port: $1599 kit, $1899 assembled. 179,200 bytes on double early 1979. A three -drive North Star density SA -400 and North Star System with quadruple capacity disk MICRO DISK SYSTEM with one double BASIC, DOS, and Monitor SA -400 included. drives will access over a megabyte of density minifloppy, controller on -line information. But, best of all board and power regulation: $699 kit, For further information, write there's no price increase double $799 assembled. (Cabinet and power for full color catalog or contact for your local computer store. density models. supply $39 extra each.) North Star BASIC and DOS have been NORTH STAR * COMPUTERS upgraded to accommodate the in- 2547 Ninth Street creased capacity and yet run existing Berkeley, California 94710 programs with little or no change. The (415) 549 -0858 new disk system also supports single

Circle 285 on inquiry card. BYTE December 1978 5 Editorial

See Sol® New Wonders of the Computer Age at all these fine by Carl Helmers computer

In recent months, trends in the development of integrated circuit technology centers have reached new highs of accomplish- CA: Costa Mesa: Orange County Computer Center, (714) 646 -0221. Modesto: Computer ment, such that it is possible to note some Magic, (209) 527 -5156. Mountain View: exciting possibilities for design in the next Digital Deli, (415) 961 -2670. San Rafael: The Byte Shop, (415) 457 -9311. Walnut Creek: year or so. These new highs are on a broad The Byte Shop, (415) 933 -6252. CO: Denver: The Byte Shop, (303) 399 -8995. CT: Bethel: front of semiconductor technology which Technology Systems, (203) 748 -6856. FL: Ft. is required for the small computers our Lauderdale: Byte Shop of Ft. Lauderdale. (305) 561 -2983. Miami: Byte Shop of Miami. readers buy and use. The effects of this (305) 264 -2983. Tampa: MicroComputer Systems, (813) 879 -4301. IL Lombard: Midwest new technology may not be seen in the (312) 495 IA: Articles Policy Microcomputer, -9889. retail marketplace for another year or so, Davenport: Memory Bank. (319)386 -3330. KY: Louisville. Martronix Associates, (502) BYTE Is continually seeking quality since there is a finite design delay time 459 -0500. MD: Silver Springs: Computers Etc.. manuscripts written by Individuals who (301) 588 -3748 Towson: Computers Etc , are applying personal computer systems, between the availability of a part's design (301) 296 -0520. MO: Florissant: Computer designing such systems, or who have specification and its appearance in finished Country, (314) 921 -4434. NH: Nashua: knowledge which will prove useful to Computerland of Nashua, (603) 889 -5238. NJ: our readers. For o more formal de- products. Cherry Hill: Computer Emporium, (609) scription of procedures and require- 667 -7555. Iselin: Computer Mart of New Jersey, ments, potential authors should send a The first new high in semiconductor (201) 283 -0600. NY: Endwell: The Computer large (9 by 12 Inch, 3a5 by 22.8 cm), technology is the announcement of several Tree, (607) 748 -1223. Syracuse: Computer Shop self- addressed envelope, with 28 cents of Syracuse, (315) 637 -6208. White Plains: US postage affixed, to BYTE Author's new 64 K bit dynamic memory parts (see The Computer Corner, (914) 949 -3282 NC: Guide, 70 Main St, Peterborough NH Raleigh: ROM's N' RAM's. (919) 781 -0003. 03458. the Texas Instruments TMS 4164 described OH: Akron: The Basic Computer Shop, Articles which are accepted are on page 209 of this issue). What are the (216) 867 -0808. OR: Beaverton: Byte Shop purchased with a rate of up to $50 per Computer Store, (503) 644 -2686. Portland: magazine page, based on technical implications of this technology for personal Byte Shop Computer Store, (503) 223 -3496. quality and suitability for BYTE'S computers? Quite simply, they are new PA: King of Prussia: Computer Mart of readership. Each month, the authors Pennsylvania, (215) 265 -2580. RI: Warwick: of the two leading articles In the reader lows in prices for the same functions we Computer Power, Inc., (401) 738 -4477. poll (BYTE's Ongoing Monitor Box or TN: Kingsport: Microproducts & Systems, (615) "BOMB") are presented with bonus see now in the marketplace. Eventually 245 -8081. TX: Arlington: Computer Port, checks of $ 100 and $50. Unsolicited the prices of the 64 K parts will fall to the (817) 469 -1502. Arlington: Micro Store, (817) materials should be accompanied by full 461 -6081. Houston: Interactive Computers, name and address, as well as return under $20 level now seen in 16 K chips (713) 772 -5257. Houston: Interactive Computers, postage. (713) 486 -0291. Lubbock Neighborhood purchased in volume. Where it once took Computer Store, (806) 797 -1468. Richardson: 32 chips of 16 K bits per chip to saturate Micro Store, (214) 231 -1096. UT: Salt Lake City: Home Computer Store, (801) 484 -6502. a personal computer's address space, it will WA: Bellevue: Byte Shop Computer Store, (206) 746 -0651. Seattle: Byte Shop of Seattle, now take only eight chips (and perhaps a (206) 622 -7196. WI: Madison: The Madison dynamic memory controller chip) to do Computer Store. (608) 255 -5552. Milwaukee: The Milwaukee Computer Store, (414)445 -4280. the same thing. It is now possible to com- DC: Georgetown: Georgetown Computer Emporium, (202) 337 -6545. CANADA: London, bine a current model microprocessor, Ontario: The Computer Circuit Ltd., (519) a video controller chip, a dynamic memory 672 -9370. Toronto, Ontario: Computer Mart Ltd., (416) 484 -9708. Vancouver, B.C.: Basic interface chip, a floppy disk controller chip, Computer Group Ltd., (604) 736 -7474. ARGENTINA: Buenos Aires: Basis Sistemas and one or two parallel interface chips Digitales, 93 -1988 or 57 -7177. AUSTRALIA: with eight memory chips and obtain a Sydney: Automation Statham, (02) 709.4144. BELGIUM: Bruxelles: S.P. R.L. Finncontact, very complete electronics module for a 2/345- 98 -95. COLUMBIA: Bogota: Video National, 326650. MEXICO: Mexico City: small computer that uses only 13 or 14 Industrias Digitales, (905) 524 -5132. integrated circuits, yet has the performance PHILIPPINES: SanJuan, Metro Manila: Integrated Computer Systems, Inc., 78- 40 -71. SPAIN: of a large scale minicomputer of several Barcelona: Interface S.A., (93) 301 7851. SWEDEN: Stockholm: Wernor Elektronik, (0) years ago. In short, the memory address 8717- 62 -88. UNITED KINGDOM: Huntingdon, England: Comart. Ltd., (0480) 74356. VENEZUELA: Los Ruices, Caracas Componentes Continued on page 205 Y Circuitos Electronicos TTLCA, 355591.

6 December 1978 © BYTE Publications Inc Circle 305 on inquiry card. Sol:The small computer that won't fence you in. A lot of semantic nonsense is spectrum. They stand up to the has a full set of extensions designed being tossed around by some of the capabilities of mini systems for the "stand alone" computer makers of so- called "personal" costing four times as much. environment. computers. To hear them tell it, an No wonder we call it the Our PILOT is an excellent text investment of a few hundred serious solution to the small oriented language for teachers. will give dollars you a computer computer question. Sold and serviced only by the to run your small business, do Sol is the small computer best dealers. financial planning, analyze data in system to do the general ledger and Sol Systems are sold and serviced the engineering or scientific the payroll. Solve engineering by an outstanding group of lab - and when day is done play and scientific problems. Use it for conveniently located computer by hour. games the word processing. Program it stores throughout the U.S. Well, the game part is true. for computer aided instruction. and Canada. The rest of the claims should be Use it anywhere you want For more information contact with a grain of salt. taken Only versatile computer power! your nearest dealer in the a few personal have the computers adjacent list. Or write Department capacity to grow and handle Build computer power B, Processor Technology, work a very real with our software. meaningful in 7100 Johnson Industrial Drive, And At Processor Technology we've sense. they don't come Pleasanton, CA 94566. Phone for peanuts. tailored a group of high -level languages, an assembler and other (415) 829 -2600. Remember, there's no packages to suit the wide In sum, all small computers free lunch. capabilities of our hardware. are not created equal So before you buy any personal Our exclusive Extended BASIC and Sol users know it to their computer, consider Soli It is a fine example. This BASIC everlasting satisfaction. costs more at the start but less in features complete matrix functions. the end. It can grow with your It comes on cassette or in a ability to use it. Sol is not cheap. disk version which has random as But it's not a delusion either. well as sequential files. Sol small computers are at the Processor Technology FORTRAN very top of the microcomputer is similar to FORTRAN IV and ProcessorTechnology Why Apple IY is the world's st selling pe$ônaI computer.

satisfaction a personal computer can bring, today and in the future. 15 cot rs & hi- resolution graphics, too. Don't settle for a black and white display! Connect your Apple to a color TV and BASIC gives you instant command of three display modes: Text, 40h x 48v Color- graphics in 15 colors, and a 280h x 192v High Resolution array that lets you plot graphs and compose 3 -D images. Apple gives you the added capability of combining text and graphics, too. Back to basics, and owners on top of what's new. assembly language too. Apple is so powerful and easy to use Apple speaks three languages: fast that you'll find dozens of applications. integer BASIC, floating point BASIC There are Apples in major universities, for scientific and financial applications, helping teach computer skills. There and 6502 assembly language. That's Which personal computer will be are Apples in the office, where they're maximum programming flexibility. And, most enjoyable and rewarding for you? being programmed to control inven- to preserve user's space, both integer Since we delivered our first Apple® II tories, chart stocks and balance the BASIC and monitor are permanently in April, 1977, more people have chosen books. And there are Apples at home, stored in 8K bytes of ROM, so you our computer than all other personal where they can help manage the family have an easy -to -use, universal language computers combined. Here are the budget, control your home's environ- instantly available. BASIC gives you reasons Apple has become such an ment, teach arithmetic and foreign graphic commands: COLOR =, VLIN, overwhelming favorite. languages and, of course, enable you HLIN, PLOT and SCRN. And direct Apple is a fully tested and assembled to create hundreds of sound and memory access, with PEEK, POKE mainframe computer. You won't need action video games. and CALL commands. to spend weeks and months in assembly. When you buy an Apple II you're Just take an Apple home, plug it in, investing in the leading edge of tech- Software: Ours and yours. hook up your color TV* and any cassette nology. Apple was the first computer There's a growing selection of pre- tape deck -and the fun begins. to come with BASIC in ROM, for programmed software from the Apple To ensure that the fun never stops, example. And the first computer with Software Bank -Basic and to keep Apple working hard, we've up to 48K bytes RAM on one board, Finance, Checkbook, High spent the last year expanding the Apple using advanced, high density 16K Resolution Graphics and system. There are new peripherals, devices. We're working to keep Apple more. Now there's a User new software, and the Apple II Basic the most up -to -date personal computer Section in our bank, to make Programming Manual. And wait till money can buy. Apple II delivers the it easy for you to obtain you see the Apple magazine to keep features you need to enjoy the real programs developed by other Apple owners. Our Software Apple peripherals New from Apple. Bank is your link to Apple owners all are smart peripherals. Valuable new series of software over the world. Watch the far right column of this ad packages for investors Now private investors can generate each month for the latest in our grow- Alive with their own stock market reports and per- ing family of peripherals. We call them form critical investment analysis instantly the sound "intelligent interfaces" They're smart with Apple II. Just log your Apple II of music. peripherals, so you can plug them in computer on to Dow Jones' central data Apple's ex- and run them from BASIC without bank with powerful Apple software: the Dow Jones Series. The first two of these clusive built -in having to develop custom software. highly practical programs speaker delivers No other personal computer comes Ad are available now. With Apple's Stock the added dimension of sound to your close to Apple's expandability. In addi- saRsuara programs. Sound to compose electronic tion to built -in video interface, Quote Reporter the cas- program, a local tele- music. Sound to liven up games and sette I /O, and four A/D inputs with two phone call educational programs. Sound, so that continuously variable game paddles, links you to any program can "talk" back to you. Apple has eight peripheral slots, three Dow Jones' That's an example of Apple's "people continuously TTL inputs and four TTL outputs. Plus updated compatible" design. Another is its light, a powerful, state -of- the -art switching stock quotes for durable injection- molded case, so you power supply that can drive all your more than can take Apple with you. And the Apple peripherals. 6000 corn - professional quality, typewriter -style panies listed on six major U.S. keyboard has n -key rollover, for fast, Available now exchanges. Current error -free operator interaction. Apple is in stock and ready for activity for stocks in delivery at a store near you. Call us for the investors portfolio is delivered Apple is the the dealer nearest you. Or, for more automatically: ask /open, bid /close, high, low and last prices, and volume traded. proven computer. details and a copy of our "Consumer 's Our Portfolio Evaluator enables Apple is a state -of- the -art single Guide to Personal Computers," call you to analyze current value of y our board computer, with advanced LSI 800/538 -9696 ** portfolio, and short - and long -term gain/ design to keep component count to a Apple loss for each stock -or for your entire or write portfolio. minimum. That makes it more reliable. Computer, Inc., Cost of Apple's Dow Jones service If glitches do occur, the fully socketed 10260 Bandley is a one time contract fee of $25, which board and built -in diagnostics sim- Drive, Cuper- includes the Stock Quote Reporter pro- plify troubleshooting. In fact, on our tino, CA gram. An additional $3 charge is made for the first three minutes of any transac- assembly line, we use Apples to 95014. tion and 500 per minute thereafter. test new Apples. To take advantage of Apple's new financial services, Apple II users need *Apple II plugs into any standard TV using only a communications card, a modem an inexpensive modulator (not included). and an ordinary telephone. This equip- "In California, call 408/996 -1010. ment, the Dow Jones Series, and a broad selection of other Apple software are Tquiry card now in stock at your local Apple dealer. leapple computr° Circle 15 on inquiry card. Apple's smart peripherals make expansion easy. Just plug 'em in and Those math I wrote programs they're ready to run. I've already Programming is a snap! last week just rewrote them using I'm halfway through Apple's BASIC I added two disks, a printer and the Apple's mini -assembler and got them communications card. manual and already I've programmed to run a hundred times faster. my own space wars game.

L 56 GREAT LOCATIONS

scheduling control, but carries the whole program right through to a daily alert ComputerLand® printout, client billing, and acquisition NOW OPEN: of advertising space and time. ALABAMA Leiteras Maybe I'm asking for too much -but Huntsville (205) 539 -1200 I have a feeling that someone out there CALIFORNIA may have already worked this out or is Dublin (415) 828-8090 at work on it. El Cerrito (415) 233-5010 PASCAL PRAISE In any event, to anyone who would Hayward (415) 538 -8080 Los Altos (415) 941 -8154 care to send me information I can use in Los Angeles (213) 776 -8080 I have just finished absorbing the my projected book and article, I would Mission Viejo (714) 770-0131 Pascal articles and editorial in the August be most grateful. San Bernardino (714) 886-6838

1978 BYTE. If I were a crowd, I'd carry San Diego (714) 560 -9912 you off on my shoulders, cheering. Larry Ashman San Francisco (415) 546 -1592 The pressure of monthly deadlines 1624 Dole St #1004 San Jose (408) 253 -8080 San Mateo (415) 572 -8080 seems to have reduced most computerist Honolulu HI 96822 Santa Rosa (707) 528 -1775 periodicals to compendia of "How I Did Thousand Oaks (805) 495 -3554 This" and "How to Make That." Recent Lawndale (213) 371 -7144 themed issues of BYTE, though, show SIGNETICS 2650: A CORRECTION Tustin (714) 544 -0542 exceptional maturity and some solid Walnut Creek (415) 935.6502 COLORADO planning. Your reasoned advocacy of a I have just finished reading "How to Colorado Springs Call Directory Assistance powerful, common language, with sup- Choose a Microprocessor" by Lou Denver (303) 7594685 Frenzel, page 124, in July 1978 BYTE. I portive material gathered into one CONNECTICUT reference issue, ranks as the most impor- feel that the advice he gives is excellent; Fairfield (203) 374-2227 tant contribution yet. however I also feel compelled to correct DELAWARE Pascal appears satisfactory for all our an inaccuracy in his section on the Newark (302) 738 -9656 purposes. The concept of p -code pro- Signetics 2650. I own and constantly use FLORIDA vides the mechanism for bringing it to a 2650 based microcomputer made by Boca Raton Call Directory Assistance Ft. Lauderdale fruition. the Central Data Corp. This is available Call Directory Assistance GEORGIA Onward, computerists! The milling in a basic 1 board configuration com- Atlanta (404) 953-0406 about is over. plete with on board programmable HAWAII memory, read only memory, cassette Honolulu Call Directory Assistance Paul F and video and It is Doering input outout (10). I LLINOIS 56 Elmore Rd expandable to an S -100 system with Arlington Heights (312) 255 -6488 Rochester NY 14618 floppy disks, 8 K and 12 K BASIC Downers Grove (312) 560 -0193 interpreters, assembler /editor, and de- Niles (312) 967 -1714 Oak Lawn 422 -8080 bugging program. Central Data also (312) Peoria Call Directory Assistance AUTOMATON TRUMPETER LIVES publishes a regular newsletter to com- INDIANA municate with the already large number Indianapolis Call Directory Assistance On pages 105 and 106 of "Antique of users of this system. KENTUCKY

Mechanical Computers, Part 2" in I have programmed PDP -11s, 8080s, Louisville (502) 425-8308 August 1978 BYTE there are references the 2650, and a SC /MP. The 2650 MARYLAND to automaton trumpeters and a state- instruction set comes closest to the Rockville (301) 948 -7676 MICHIGAN ment that none survive. power of the PDP -11, and I find it a real Grand Rapids (616) 942 -2931 I just returned from Europe and ob- pleasure to use. Southfiel d (313) 356 -8111 Deutsches Museum in served at the MINNESOTA Munich Germany a life -sized auto- Gordon Brandly Bloomington (612) 884-1474 maton trumpeter. One half (left side) RR 2 NEW HAMPSHIRE is clothed and the other half is exposed Fort Sask Nashua (603) 889 -5238 so that the mechanism is visible. Pressed Alberta CANADA T8L 2N8 NEW JERSEY for time, I was not able to find out if it Cherry Hill (609) 795 -5900 still operates, or who constructed it. Bergen County (201) 845 -9303 SOME REFERENCES ON Morristown (201) 539 -4077 NEW YORK William Harmon NETWORKING AND PROTOCOLS Buffalo (716) 836 -6511 2662 Grand Summit Ithaca Concerning your editorial in July (607) 277 -4888 Torrance CA 90505 NO. CAROLINA 1978 BYTE, there are two pieces of Charlotte (704) 536 -8500 literature which your readers may want OHIO COMPUTERS AND ADVERTISING to review. Both concern the Octopus Cleveland (216) 461 -1200 computer network in use at Lawrence OREGON

I am working on both a book and a Livermore Laboratory in Livermore Portland (503) 620-6170 magazine piece about the use of com- CA, which is one of the campuses of the PENNSYLVANIA puters in the field of advertising- parti- University of California. Harrisburg (717) 736-1116 TEXAS cularly in media control, including The first article is in Dotomotion, Austin (512) 452 -5701 19 1973, pages 58 63. The production scheduling, space acquisition April thru Dallas Call Directory Assistance and scheduling for print and broadcast second article is in Computer Design, Houston (713) 977 -0909 media. July 1978, pages 77 thru 86. WASHINGTON I would be grateful if any BYTE The most impressive points of the Bellevue (206) 746 -2070 readers with experience in this relatively Octopus network design are simplicity of Federal Way (206) 838 -9363 Tacoma untapped software area could send me both software and hardware implemen- (206) 581 -0388 WASHINGTON, D.C. Call Directory Assistance any information they may have, includ- tation; suitability for use with standard, WISCONSIN ing any programming information which inexpensive, byte oriented, asyn- Madison (608) 273 -2020 might be helpful. chronous modem hardware; and easy INTERNATIONAL I am also interested in a program Sydney, NSW Australia 29 -3753 which not only includes production and Continued on page 158 Winnipeg, Canada Call Directory Assistance

10 December 1978 © BYTE Publications Inc Circle 75 on inquiry card. f$ff#1 BEFOREYOU NITCIMPIITERI, COMPUTERLAND

If the truth is that you want a computerize things like accounting, computer ... then we want to be your inventory control, record keeping, word computer store. processing and more. The net result is the Were ComputerLand, the #1 reduction of administrative overhead and computer store chain in the U.S. What's the improvement of efficiency which allows meaningful about that fact is, that the business to be managed more ComputerLand has been chosen by more effectively. people as having what they've been In the home, a computer can be used looking for. And, since you're looking, let for personal budgeting, tracking the stock us tell you what you'll find, when you visit market, evaluating investment opportunities, a ComputerLand store. controlling heating to conserve energy, You'll find a product line that's running security alarm systems, automating continually evaluated to provide you with the garden's watering, storing recipes, the widest and best selection in quality, designing challenging games, tutoring the brand name microcomputers anywhere. children ... and the list goes on. You'll find an enthusiastic and In industry, the basic applications are knowledgeable staff able to interpret all in engineering development, process the equipment specifications, in terms of control, and scientific and analytical work. how they apply to you, and in a way Users of microcomputers in industry you'll understand.You'll find demonstration Enough about us. How about what have found them to be reliable, cost - areas where you can get a firsthand computers do.To attempt to describe all effective tools which provide computing experience of running a computer yourself. the things your computer might do, would capability to many who would otherwise be to describe your imagination. So have to wait for time on a big computer, instead, well briefly list some of the many or work with no computer at all. COMPUTERS things for which small computers are already being used. FOR BUSINESS In business, the advent of the COMPUTERS versatile and compact microcomputer has put the benefits of computing within reach FOR INDUSTRY of small companies. With systems starting at less than $6000, the businessman can

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BYTE December 1978 11

DYNABYTE COMPUTERS ARE ALL BUSINESS INSIDE AND OUT.

When we designed our new small TRAN and COBOL programming lan- operator safety. business computers, we meant busi- guages. Our applications packages in- Since we didn't cut corners in de- ness. clude general ledger, accounts receiv- sign, the price /performance ratios of As basic as that seems, it is unique. able, word processing and many other our systems make good business sense. Just about every other microcomputer CP /M compatible programs. being sold as a small business system Reliability is a big consideration in THE INSIDE FACTS The DB8 /2 Computer System in- today was originally designed as a kit buying a business computer, so we built cludes two 5 -inch disk drives either for hobbyists. it in. Our edge connectors meet military single or double sided for up to 1.2 Every design decision was made specifications, the toughest electronics megabytes of mass storage; a 4MHz with quality and reliability in mind. The manufacturing standard. Our regulated Z -80 processing module with one result is dependable performance and a power supply is designed to meet U.L. parallel and two serial ports, an solid appearance for business, profes- standards, which means the entire sys- EPROM programmer and up to 4k sional and scientific applications. tem runs cool and dependable. And our ROM; 32k of RAM, a 12 -slot fully - cast aluminum enclosures are rugged as FIRST SYSTEM WITH populated backplane; our exclusive SMALL well as attractive. BIG SYSTEM STORAGE Dual Density Disk Controller, and Many applications handle large AND THE BIGGEST CP /M. quantities of information, so the DB8 /2 THING OF ALL The DB8 /1 Computer includes a uses two quad density 5 -inch disk Customer support. Our support 4MHz Z -80 processor with one parallel drives with our exclusive Dual Density starts at the factory with testing and and two serial I/O ports, an EPROM Disk Controller for up to 1.2 megabytes bum -in programs that assure the entire programmer and up to 4k of ROM; 32k of formatted storage. That's more integrated system is reliable prior to RAM, and a 12 -slot fully -populated capacity than two single density 8 -inch shipment. Our completely modular de- backplane. drives. sign allows continuing support in the The DB8 /4 Disk System, designed If you need more storage, our field. We maintain a bonded inventory to be the mass storage companion to the DB8/4 has two 8 -inch drives with up to of all sub -system modules which means DB8 /1, includes two 8 -inch floppy disk 2 megabytes capacity, more than any we can deliver replacement sub- drives in either single or double sided other dual floppy disk system on the assemblies overnight nearly anywhere configuration for up to 2 megabytes of market. in the continental U.S. mass storage, our Dual Density Disk Dynabyte built in little things, too. Controller, and CP/M. OUR SOFTWARE IS Like a fully -populated 12 -slot All three units will be available in BIG ON BUSINESS backplane, switched AC outlets for ac- rack mount models. Dynabyte helps you get down to cessories, an option for European For a descriptive brochure and business immediately. The DB8/2 is the power, quiet whisper fans with long-life price list, call or write Dynabyte, 1005 first microcomputer to offer enough metal construction, lighted indicator Elwell Court, Palo Alto, CA 94303. storage capacity on 5 -inch drives to switches for Power On and Halt, a Phone (415) 965 -1010. fully utilize CP/M,* the most widely shielded enclosure to protect disk drives Or better yet, see yourlocal dealer. accepted disk operating system. We from electro- mechanical interference, also supply and support BASIC, FOR- and a fully enclosed power supply for CP/41 is a trademark of Digital Research. DUflDUTE YOU CAN DEPEND ON It

Circle 110 on inquiry card. BYTE December 1978 13 fast Fourier Transforms (a) on Your Home Computer

(b)

Figure 1: An arbitrary continuous signal x(t) expressed as a function of time (a) may also be described by its spectrum or Fourier transform X(f), which is expressed as a function of frequency (b). The relative strength of the spectrum at different frequencies is a measure of the frequency content that comprises the given signal. The concept of spectrum finds numerous applications in many varied disciplines including music waveform analysis, communications signal analysis, mechanical vibrations, oceanography, statistics, and others. In signal analysis, the function x(t) is said to be a time domain representation, and X(f) is said to be a frequency domain representation.

The advent of the home computer makes the signal. This description is called the possible many new and varied applications spectrum of the time signal and, mathe- William D Stanley both of a general nature and of a scientific matically, it is the Fourier transform of the Steven J Peterson or mathematical nature. One of the latter time function. The process of Fourier trans- Dept of Electrical Engineering applications we have successfully imple- formation is represented by the mathemati- Old Dominion University mented on a personal computer is the fast cal function Norfolk VA 23508 Fourier transform, which we will subsequently refer to as the FFT, according to °O -j27rft X(f) = x(t)e dt standard usage. Some of the most important f properties of the FFT are described in this article, and an FFT program written for the where X(f) is the Fourier transform of x(t). Digital Z -80 Group System using BASIC [The constant j is used in electrical engineer- is provided. ing to denote also called i. The number e, 2.71828, is the base the natural Continuous Fourier Transform of algorithms.... CM] For all but fairly simple Before discussing the FFT in particular, functions, this mathematical process repre- it is desirable to briefly survey some of the sented a formidable operation for many general concepts of the classical continuous years. Prior to the development of the digital Fourier (pronounced "foor -yay ") trans- computer, many analytical and experimental form. The terminology used refers to time methods were investigated for determining and frequency since they are among the the approximate spectra of functions that most common variables of interest in many arose in physical systems. applications, although the theory involved The magnitude of a typical spectrum is

applies to a variety of different types of shown in figure 1 b and is denoted by IX(f)I, physical phenomena. where f represents the frequency in Hertz Consider the waveform x(t) shown in (Hz). For example, if x(t) were a music sig- figure la which is displayed as a function of nal, strong peaks of the spectrum at low time (denoted by t). The waveform can also frequencies would be characteristic of a sig- be described by the frequencies present in nificant amount of bass content such as

14 December 1978 © BYTE Publications Inc In the midst of the talk and the promises. .1.

PerSci delivers the Dual- Headed Diskette Drive that works and the Double Density IBM Compatible Controller to back it up. While everyone else was waiting and design, PerSci backs up the 299 with the first avail- promising - PerSci did it! Designed the industry's able double density, dual -head flexible disk first fully reliable, field proven, dual -head controller -the Model 1170 -for all applications design -now available in a high technology dual requiring IBM 2D, IBM 3740 or S -100 bus compatibil- diskette drive, the PerSci Model 299. The 299 has a ity. The PerSci 1170 is Z -80 based, the smallest, most total of four heads handling two double -sided intelligent floppy disk controller on the market. diskettes -providing up to 3.2 Mbytes of The PerSci 299 and 1170 controller are de- data in a drive the size of a standard signed with the same advanced floppy. And because the Model 299 has technology that has made PerSci voice coil positioning, this dual diskette number three in diskette product ship- drive can seek data four to six times PERSti ments (and moving up). Don't wait faster than possible on two independ- around for more talk and more prom- ent stepper motor drives. All offered ises. Call PerSci for full information. by PerSci at a highly competitive PerSci, Inc., 12210 Nebraska Avenue, OEM price. Peripherals a West Los Angeles, California 90025. To save time and money in systems Generation Ahead. (213) 820 -3764. Circle 289 on inquiry card. BYTE December 1978 15 drums or tubas. Conversely, many string Observe that the inverse transform has essen- instruments such as the violin display tially the same general form as the direct stronger peaks at higher frequencies in the transform except for the sign of the expo- audio spectrum. The frequency spectrum (or nential argument. Fourier transform) thus provides a plot of The concept of the frequency spectrum the relative weight of different frequencies has long played a most important role in that comprise or represent the given signal. numerous scientific applications and has If the Fourier transform or spectrum of a been of interest to mathematicians, engi- signal is known, the time function may be neers and scientists of many different dis- determined from the inverse transformation ciplines. Among the areas where spectral which is given by analysis has been employed are sound and music analysis, communications systems 00 j2rrft design, analysis of mechanical vibrations, X(t) = f X(f)e df ocean wave analysis, statistics and many others.

(n) Discrete Fourier Transform

The heart of the F FT is a mathematical operation known as the discrete Fourier transform (DFT). In the DFT, a set of integers n and m are defined to represent the equivalent in a sense of the time and frequency variables, respectively, of the continuous Fourier transform. This correspondence is best seen by observing the sampled signal x(n) shown in figure 2a. There are POINT WHERE NEW assumed to be N samples of the signal / PERIOD BEGINS spaced T seconds apart. Thus, as n varies i i t from 0 to N -1, the N samples of the time N -I TIME INTEGER +{T signal are generated. The duration of the

ID time signal is tp = NT. The DFT of x(n) is defined by the finite summation IX (mll N-1 X(m) t` x(n)Wmn Ñ n[=J0 1e where W_e-j27r N

The function X(m) represents a discrete spectrum with m serving the same purpose POINT WHERE NEW in frequency as n did in time. The frequency ( PERIOD BEGINS increment between successive components is

F = 1 /tp so that the spectral component at a

N/2 N -I FREQUENCY INTEGER frequency mF is X(m). For x(n) real and for F h- (HARMONIC NUMBER) N time points, a unique spectrum can be (b) r5 computed only at N/2 frequency points. Actually, X(m) is periodic in m with N Figure 2: A sampled function of time (a) and its discrete Fourier transform points in each period, but only N/2 are spectrum (b). The discrete Fourier transform (DFT) functions are used to unique. X(m) is, in general, a complex func- approximate the continuous transform functions whenever digital implemen- tion consisting of a real and an imaginary tation is to be used. The time function is sampled at N points separated by an part at each frequency. For many applica-

increment T over an interval tp = NT to create a discrete function x(n). The tions, the magnitude spectrum IX(m) I is the resulting spectrum X(m) is periodic with a period fs = 1 IT and contains N quantity of most significance. Some of the components within one period with spacing between components F = 1 /tp. If preceding points are illustrated in figure 2b. x(n) is. a real function, only half or N/2 of the spectral components are As in the case of continuous signals, an

unique. The integers n and m represent the time and frequency integers which inverse discrete Fourier transform ( I D FT) identify the location in the sequence of the time sample (t = nT) and the can be defined. In this case, the inverse frequency component or harmonic number (f = mF). transformation is

16 December 1978 © BYTE Publications Inc It may be a hobby, or it may be an asset...

It SHOULD be a Heathkit P Computer System

No matter what your computer system Il and our new floppy disk, you'll have state-of- SEND FOR YOUR needs may be, Heathkit computers make the-art computing power at its very best! FREE CATALOG sense! Heathkit "total design" computer systems give you a wide selection of OUR PERIPHERALS Read all about these Heathkit computer peripherals, software programs to get products and peripherals in the new FREE you up and running fast; plus the reliabil- The Heathkit Computer peripherals offer the Heathkit catalog. Write Heath Company, ity, service and responsibility that come same competitive advantages of our two Dept. 334 -482 for your FREE copy. Or visit from being a leader in the electronics computers. Our H9 CRT terminal, H10 paper your Heathkit Electronic Center (Units of industry for some 50 years! tape reader/punch, ECP -3801 cassette stor- Schlumberger Products Corporation). age recorder /player, and our new WH14 line printer, plus the new floppy disk storage systems all give you the quality, performance HEATHKIT OUR 8 -BIT COMPUTER and value that Heath company is famous for. And we sell the memory, I/O interfaces Every Heathkit Computer Product is designed and accessories you need to custom design COMPUTERS a system to your particular specifications! to offer substantial benefits over competitive Systems Engineered products on the market. Our 8080A -based for Personal Computing H8 for example, is more than just a simple ALL THIS. 8 -bit machine. With its "intelligent" front panel and keyboard entry and digital dis- PLUS HEATH DOCUMENTATION, play, it actually lets you compute and pro- SERVICE AND SUPPORT gram without the addition of any peripherals. It's an ideal computer training system, and One of the most important parts of ANY com- when you're ready to advance, it's ready too. puter system is documentation. And Heath It's one of the most expandable computers documentation is quite simply, the best around, and now with its NEW floppy disk around. If you buy our computer products in system, it could be the only computer you'll kit form, you get a comprehensive step -by- ever need. step assembly manual that takes you every step of the way from unpacking to final plug - in. The knowledge you gain in building your Heathkit computer is invaluable -for service OUR 16 -BIT COMPUTER if it's ever needed, for quick troubleshooting and correction, and just for understanding If you need the power, speed and versatility the workings of the machine. In both our kit of a 16 -bit machine, there's nothing better and fully assembled products, our compre- than our H11A. Based on the famous DEC LSI- hensive operating and instruction manuals 11/2, the H11A provides complete DEC com- are fully detailed, thorough and accurate. patibility and access to the thousands of This documentation, plus Heathkit technical practical software programs and applications consultants and service nationwide, make that entails. Along with our own complete your Heathkit computer system one you can Heath Co. Dept. 334 -482 systems software and our line of DEC -com- depend on -to work right the first time, and Benton Harbor, MI 49022 patible peripherals including the DEC Writer to last for years! CP -159

Circle 160 on inquiry card. BYTE December 1978 17 compute the spectrum at one particular N-I value of m Since there are N/2 uniq re -'nn x(n) = X(rn)W spectral components, the total number of m=0 computations required to generate a corn plete spectrum is of the order of N2. The The resulting function is periodic in the vari- Cooley -Tukey algorithm, published in 1965, able n and has N points in one period. Thus, demonstrates one way to perform this even if the original time signal were not transformation with a number of computations of the order of N log7(N), which turns out to be an enormous savings in computational time for long signal records. The Cooley -Tukey algorithm, along with subsequent variations, is referred to as the fast Fourier transform (FFT). Thus, the FFT is a high speed algorithm for computing the discrete Fourier transform. While the DFT is a finite summation and the classical Fourier transform is an integral transform, the DFT may be used to closely approximate tire continuous function under many circumstances. Some of the concepts involved with such an approximation are considered later in this article. The various FFT algorithms work best when the number of points in the sample record is an integer power of 2, ie: N = 2k, where k is an integer. The form of one of the basic algorithms is shown in tigure 3 for the case of N = 8. Obviously, N = 8 is far too small for most application's, but the flow graph is of interest in understanding the form of the general computational algorithm. This particular algorithm is referred to as an in place algorithm since at each stage of the computation, the data may be stored in the same memory locations from which they were obtained. Figure 3: Flow diagram indicating the computations involved in an 8 point fast Fourier transform (FFT) implementation of the discrete Fourier trans- Implementation of In Place Algorithm form (OFT) function. Significant reductions in computation time are achieved with FFT realizations of large arrays. For example, the computa- The in place algorithm previously dis- tioti time for a 1024 (27°) sequence of samples using an FFT is approxi- cussed was implemented on the Digital mately 1 percent of the time required by direct application of the DFT. Group Z -80 System using BASIC. The pro- In the chart, two paths merging together in a given column represent a gram is given in listing 1. The particular combination of two quantities in the preceding column. For example, system used had 18 K bytes of memory, the first quantity in the second column is obtained by forming x(0) + of which about 12 K bytes were required W0x(4). The first term is indicated by the dashed line and the second is for the BASIC software. It was determined indicated by the solid line. The integer in the circle is the power of W. (See that a 256 point transform could be com- text for definition of W.) The pattern continues until the spectrum appears puted with this system and the program in the last column. This particular algorithm for the EFT results in a scram- listed uses this capacity. It could be readily bled order for the spectral coefficients as can be seen from the chart. Some expanded or contracted as the available variations result in a natural order but require more internal memory. memory size dictates. However, the size selected should be chosen as an integer power of 2 as previously noted. Thus, the periodic, the operation of the IDFT pro- next smaller size should be 128 and the duces a function capable of providing the next larger size should be 512. desired results in one cycle, but the pattern In order to reduce the memory require- continues to repeat itself if the interval is ments, the trigonometric functions are extended outside of the basic range. generated as they are required in the pro- Observation of the definition of the DFT gram. This approach is not nearly as effi- reveals that there are approximately N com- cient from the standpoint of computation plex multiplications and about the same time as would be the process of initially number of complex additions required to generating and storing the functions in

18 December 1978 O BYTE Publications Inc 'pm$549

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CPU - Besides combining the 6800 with the S =100 THE SYSTEM - I he basic SYSTEM 1 features our bus. the MD -690A is truly a system on a hoard. Fea- custom console. keyboard. S -100 bus motherboard. tures include 1K RAM. 20 I/O bits, an 16 amp power supply. fan, 64: X 16 RS 232 interface. a 2400 baud cassettes upper and lower case video /graphics interface, and .10K PROM spate per- -- card. and the MD -690A CPU board - milting the option of 8K BASIC in PROM. ° all for $549 tkit)! The SYSTEM 2 adds our 32K RAM card populated with MONBUG- The 1K PROM monitor at ' 8k of RAM and is priced at just $699 the heart of THE SYSTEM is compatible '4! (kilt. with the standard 6800 ROM. As a result. ----- uuuwmwmuuttttutmmmuuuu{ virtually all 6800 software will run on THE PERIPHERALS - As your computing 4YSTEM. But MONBUG outputs to our //re .1/0690/1 needs grow. MicroDaSys Offers a full memory -mapped video card permitting graphic s. line of system peripherals including a minifloppy animation and our exclusive memory window. And disc and controller, an assortment of printers, and a the interrupt driven keyboard input is ideal tormulti- full line of S -100 products. Our newest addition is an tasking applications. MONBUG is only available on 1.0 card with 8 parallel ports 180 I/O bits), 2 serial MicroDaSys systems. ports and a full duplex modem for $149 (kit).

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- POST OFFICE BOX 36051 LOS ANGELES. CA 90036 (213) 935-4555 Circle 219 on inquiry card. BYTE December 19 7/1 19 DEALER INQUIRIES INVITED VISA AND MASTER CHARGE ACCEPTED. Listing 1: Fast Fourier transform routine 1270 IF A$<>'NO' THEN 1240 described in text. Lines 10 to 499 are avail- 1280 END 1290 REM - SCRAMBLER SUBROUTINE - able for the user to describe the time func- 1300 Y =0 : N1 =N 1310 FOR W =1 TO L tion that is to be studied. 1320 N1 =N1/2 1330 IF X

6 REM -- , GENERATE TIME FUNCTION - 1370 RETURN 10 REM 1380 REM - MAGNITUDE (X3) SUBROUTINE 20 REM LINE NUMBERS 10 -499 ARE USED TO 1390 GOSUB 1300 30 REM GENERATE OR INPUT THE T1ME FUNCTION 1400 X3 =SORT(X1(Y) -2 + X2(Y) -2) 40 REM 1410 RETURN 500 PRINT 'DO YOU WANT A LISTING OF THE GENERATED TIME FUNCTION 1420 END 510 INPUT Af 520 IF Af ='NO' THEN 640 530 IF Af< ?'YES' THEN 500 540 B =X1(0) 550 FOR Z =0 TO N -1 memory so that they can simply be called 560 IF ABS(X1(Z))B THLN B= ABS(X1(Z)) 580 NEXT Z as required. However, where speed is not a 600 FOR Z =0 TO N -1 major priority, this approach minimizes 610 PRINT X1(Z)iTAB(41 +20 *X1(Z).'B)i' *' 620 NEXT Z the total memory required. 630 REM - SCALE INPUT TIME FUNCTION - in 640 FOR Z =0 TO N -1 Statements 10 through 499 the pro- 650 X1(Z) =X1(Z) /N gram represent the particular input signal 660 NEXT Z which the transform is being computed. 670 REM - - FFT IN -PLACE ALGORITHM - - for 675 PRINT' - FFT CALCULATION IN PROGRESS -' The time function may be generated by 680 I1 =N /2 : I2 =1 1 V= 2 *P1 /N as 690 FOR I =1 TO L appropriate equations or an algorithm 700 I3 =0 : I4 =I1 will be demonstrated for several cases later. 710 FOR K =1 TO I2 720 X =INT(I3 /I1) For experimental data, the values could 730 GOSUB 1300 be listed point by point if the function 740 I5 =Y 750 Z1 =COS(V *I5) cannot be readily described by an equation. 760 Z2 =- SIN(V *I5) 770 FOR M =I3 TO I4 -1 780 Al =X1(M) : A2 =X2(M) Applying the Program 790 B1 =Z1 *X1(M +I1)- Z2 *X2(M +I1) BOO B2 =Z2 *X1(M +I1) +Z1 *X2(M +I1)

810 X1(M) =A1 +B1 : X2(M)=A2 +B2 In order to effectively utilize an FFT

820 x1(M +I1) =A1 -B1 : X2(M +I1) =A2 -B2 830 NEXT M program for spectral analysis, it is neces- 840 I3 =I3 +2 *I1 1 I4= I4 +2 *I1 sary to understand some of the peculiarities 850 NEXT K

860 I1 =I1 /2 : I2 =2 *I2 of the DFT and its relationship to the con- 870 NEXT I tinuous Fourier transform. Although the 880 REM - OUTPUT RESULTS - 890 PRINT'IN WHAT FORM DO YOU WANT THE OUTPUT 7' time signal may or may not be periodic in 900 PRINT' MAGNITUDE SPECTRUM PLOT (1)' nature, the mathematical form of the DFT 910 PRINT' TABLE OF VALUES (2)' 920 INPUT A treats the signal as if it were periodic. The 930 IF A =1 THEN 970 total duration of the time signal is the period 940 IF A =2 THEN 1130

950 PRINT'INCORRECT INPUT (1 OR 2)' : GOTO 890 tp, and for the program being considered, 960 REM - OUTPUT MAGNITUDE SPECTRUM PLOT - this period contains 256 points. If T is the 970 B =0 975 PRINT' - CALCULATIONS IN FRUGNE51, time increment between samples, then 980 FOR Z =0 TO N/2 tp = 256 T. The spectrum obtained from the 985 X -Z 990 GOSUB 1390 DFT is also periodic and contains N (or 1000 IF X3>B THEN B =X3 256) spectral components. However, for a 1010 NEXT Z 1020 FOR Z =0 TO N/2 time function that is real (which incidentally 1025 X =Z is 1u3u GOSUB 1390 the case for all signals considered in this 1040 X4 =INT(5S *X3 /B) article), it can be shown that half of the 1050 C =0 components are ambiguous; ie: they are 1060 PRINT Z ;TAB(5)i'!'i 1070 C -CFI similar to the other half and do not repre- 1080 IF C;X4 THEN FRINT'='i : GUM 1070 1090 PRINT " sent any actual spectral information. Thus, 1100 NEXT Z there are N/2 (or 128) meaningful complex 1110 GOTO 1240 1120 REM - OUTPUT TABLE OF VALUES spectral components that are obtained with 1130 U -0 the FFT. These components are spaced apart 1140 Z =0 1150 PRINT' HARMONIC 'iTAD(14)i'REAL':TAB(3O)i in frequency by F = 1 /tr. The value for 1160 PRINT 'IMAGINARY'iTAB(5O)i'MAGNITUDL' m = 0 corresponds to the DC component, 1165 X =U 1170 GOSUB 1390 m = 1 is the fundamental, m = 2 is the sec- 1180 PRINT UiTAB( 10) 1X1(Y);TAB(3O);X2(Y);TAB(5O)IX3 ond harmonic, etc. According to sampling 1190 U =U +1 : Z -Z1.1 1200 IF Z >9 THEN 1140 theory, a time signal must be sampled at a 1210 IF U >N /2 THEN 1240 1220 GOTO 1165 rate at least equal to (practically speaking, 1230 REM - TERMINATE 7 - greater than) twice the highest frequency 1240 PRINT'DO YOU WANT ANOTHER OUTPUT (YES, NO)'; 1250 INPUT Af contained in the spectrum. Thus, if the 1260 IF A$ ='YES' THEN 890 highest frequency contained in a spectrum

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Circle 24 on inquiry card. BYTE December 1978 21 10 REM - GENERATE 25X. PULSE is known to be no greater than fh, the maxi- 20 FOR Z =0 TO N/4 mum time between samples (T) should be 30 X1(Z) =1 40 NEXT Z chosen to satisfy T < Zfh. If this condition 50 FOR Z =N /4 TO N 60 X1(Z) =0 is not met, there will be a spectral overlap 70 NEXT Z or aliasing effect which will distort the spectrum. 10 REM - GENERATE 12.5X PULSE 20 FOR Z -0 TO N/8 For a fixed number of points (such as 30 X1(Z) =1 256 for the program under discussion), there 40 NEXT Z 50 FOR Z =N /8 TO N is a trade -off between the high frequency 60 X1(Z) =0 capability and the spectral resolution. In 70 NEXT Z order to analyze higher frequencies, a shorter sampling time is required, but this 10 REM - GENERATE 1000HZ SINE NAVE 20 T =0 necessitates a shorter overall period and a 30 FOR Z =0 TO N -1 40 X1(Z) =SIN(2A3.14159411000 *T) larger increment between successive fre- 50 T =T +1.953125E -4 quencies. Specifically for 256 points, N/2 = 60 NEXT Z 128; and since N = 0 corresponds to DC, the highest frequency that can be measured is 10 REM - GENERATE 1010Fä SINE WAVE 127 times the spectral resolution. It is very 20 T =0 30 FOR Z =0 TO N -1 important that the sampling rate be chosen 40 X1(Z) =SIN(2413.14159$1010AT) to be greater than twice the highest fre- 50 T= T +1.953125E -4 60 NEXT Z quency in the spectrum even if the higher frequencies are not of interest. If the mini- Listing 2: Three different generating routines that can be used with listing 1 mum sampling rate requirement is not met, as the time functions. The first routine generates a pulse function that lasts erroneous spectral components may appear 25 percent of the time that is being analyzed. The second routine also gen- at various places in the spectrum. erates a pulse but half as long as the first routine. The third and fourth There are various other properties of the routines generate sine waves which are only slightly different. DFT that may be important in applying an FFT program in various situations. The reader is encouraged to consult one of the references listed at the end of this article or (n) the many other available sources for more extensive details, since this article provides only a brief overview of the theory along with the details of a workable program for a home computer. 64 POINTS Examples

Several examples that illustrate some of the properties of the F FT are now considered. The various function programs for iD N 256 POINTS these waveforms are shown in listing 2. The first example is that of a single rectangular Figure 4: Rectangular pulse for which the FFT is partially displayed in pulse whose duration is 25 percent of the photos 1 and 2. The pulse is unity for 64 of the 256 points in the time total period corresponding to 256/4, or 64 record and zero for the remainder. points as illustrated in figure 4. (Due to the

Figure 5: Rectangular pulse for which the .(n) FF7 is partially displayed in photo 3. The pulse is unity for 32 of the 256 points in the time record and zero for the remainder. Since this pulse is shorter than the one of figure 4, the spectrum is broader. In gen- 32 eral, there is an inverse relationship between POINTS the width of a pulse -like time function and the width of the frequency spectrum. This property is un important concept in signal transmission and results in the re-

quirement of larger bandwidths for trans- tp mitting shorter pulse signals. 256 POINTS

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ti 44 10 11 ,9tr 1978 23 ± .'I5 . large number of points, the function is indicated in figure 5, the magnitude spec- shown as a continuous curve.) The video trum changes to the form shown in photo 3. display of the first 14 spectral components It should be pointed out that the band- in tabular form is shown in photo 1, and the width of a rectangular pulse is theoretically first 15 components of the magnitude spec- infinite in extent and so there is some alias - trum are displayed in photo 2. Henceforth, ing error in each of these cases. However, the only the magnitude spectra will be shown. effects of aliasing are not pronounced in When the pulse duration is changed to these two examples over the frequency range 12.5 percent of the period or 32 points as shown in the photos. At larger harmonic

KRIM

Photo 1: The first 14 components (DC and harmonics up through the 13th) of the FFT spectrum corresponding to the pulse shown in figure 4. The program lists the real 8 8 part of X(m), the imagi- 9 1.95E9E-412 nary part X(m) and the of 18 3. 9EIBIEE13 magnitude IX(m) I. 11 -1.2427581p& u 0 13 .81489184

Photo 2: Video graphics display of the magnitude spectrum Photo 3: Video graphics display of the magnitude spectrum corresponding to the pulse shown in figure 4. The display is corresponding to the pulse shown in figure 5. of course rotated 90° from the basic mathematical form illustrated in figure 2

24 December 1978 0 BYTE Publications Inc values for the given signals and at shorter truncation and sampling processes in order pulse widths for the given frequency range, to properly evaluate results. The phenomena the aliasing errors would be more significant. just noted can be reduced by smoothing the A sine wave representing an assumed fre- data to be transformed with certain window quency of 1000 Hz and an assumed sampling functions before computing the FFT. Win- time of T = 0.1953 ms was generated and dow functions smooth the beginning and analyzed. The resulting spectrum is shown end of a record length and reduce the effects in photo 4. Note that the frequency resolu- of leakage on the spectrum. tion is F = 1/(0.1953 x 10 -3 x 256) = 20 Hz so that 1000 Hz corresponds to harmonic More Examples number 50. Observe that an ideal single line appears as one might hope. On the other Other applications include the use of an hand, when the frequency is changed to analog to digital converter to sample speech 1010 Hz while maintaining the same value of and music waveforms or the waveforms en- T, the spectrum changes to the form shown countered in electronic systems. The sample in photo 5. The reasons for the striking points could be stored for later spectral difference are as follows: In the first case, analysis using the FFT program. We hope the frequency corresponds exactly to one of readers will be encouraged to experiment the harmonic numbers (50th harmonic), and with the program on their own computers. a property of the DFT is that no other line components appear in this case. However, in the second case, the component would REFERENCES theoretically appear halfway between the 50th and 51st harmonics so that the imper- 1. Bergland, G D, "A Guided Tour of the Fast fections of the finite time duration of the Fourier Transform," IEEE Spectrum, July 1969, pages 41 thru 52. observed sinusoid are now apparent. The 2. Brigham, E O, The Fast Fourier Transform, phenomenon observed is called leakage. It Prentice -Hall, Englewood Cliffs NJ, 1975. can also be readily verified that the first si- 3. Cooley, J W, and Tukey, J W, "An Algorithm nusoid was observed over an exact integer for the Machine Calculation of Complex Fourier number of cycles, while in the second case, Series," Math of Computation, volume 19, April 1965, pages 297 thru 301. the was a sinusoid truncated during cycle. 4. Stanley, W D, Digital Signal Processing, Reston This example illustrates the necessity of Publishing Co (a division of Prentice -Hall), understanding some of the limitations of the Englewood Cliffs NJ, 1975.

Photo 4: Video graphics display of the magnitude spectrum Photo 5: Video graphics display of the magnitude spectrum corresponding to a sine wave whose assumed frequency is corresponding to a sine wave whose assumed frequency c 1000 Hz with a sampling interval T = 01953 ms. This 1010 Hz with a sampling interval T = 0.1953 ms. This fr assumption results in an integer number of cycles (50) in the quency corresponds to the midpoint between the 50th anu record duration tp, which corresponds to 50 ms. The fre- 51st harmonics, and the imperfections of the DFT in repre- quency then corresponds exactly to the 50th harmonic and senting a continuous time signal now can be seen. the spectrum appears as a single line.

December 1978 © BYTE Publications Inc 25 Designing a Universal Turing Machine

A Software Approach

Thomas Munnecke Hardware or software; which is best? This The reader is referred to Millen's article Metasystems question faces many designers when creating for a complete description of the universal 6199 Shaker Dr new systems. This article describes a soft- Turing machine. His design implements Riverside CA 92506 ware version of a hardware project detailed this machine with about 15 integrated in December 1976 BYTE by Jonathan K circuits. The memories are 2102s, the head Millen in his article "A Universal Turing and program counter are counters, and the Machine," page 114. control logic consists of various flip flops, The universal Turing machine (UTM) is shift registers, clocks and decoders. The elegantly simple and capable of emulating memories are loaded and examined with the instruction set of any computer. The switches and a 7 segment light emitting Turing machine was invented by Alan Turing diode (LED). The design is capable of (1912 -1954). It is an abstract computing executing about 40,000 instructions per device that contains all the fundamental second. properties a computer system must possess and is used to study computer concepts. A Software Approach Although difficult to program, its back -to-

basics nature is alluring to anyone interested The program in listing 1 is the logical in the fundamentals of computers. equivalent of Millen's hardware version The universal Turing machine designed for the Motorola 6800 processor. The pro- by Jonathan Millen has two memories: one gram storage, tape, program counter and for program storage and the other for the head are parts of the computer's memory set main storage or "tape." The tape is a sup- aside for those purposes. The memory organ- posedly infinite (but actually 1024 bits long) ization is shown in table 1. The rest of the memory which is a series of 1s and Os. A bit logic is programmed via the 6800's instruc- on the tape is pointed to by a counter tion set. Table 2 is a comparison of the known as the head. A program counter various functions and their implementation points to a state in the program being exe- in the two approaches. cuted. Each state consists of two instruc- The program is a relatively straightfor- tions: one to be used if the current bit under ward programming of the hardware version. the head of the tape is a 1, the other if it is a The basic cycle of functions to be performed O. Each instruction contains fields describing is:

whether to write a 1 or a 0 on the tape, which direction to move the tape (left or Test the bit on the tape under the right one position), and the address of the head. be next state to executed. Write a 1 or 0 according to the write Each instruction contains the following bit of the instruction indicated by the information: program counter and the tape bit. Move the tape (adjust the head) Bit 0: Write bit. Write this bit on according to the instruction's direc- the tape after the head is tion bit. adjusted. Set the program counter equal to the Bit 1: Direction bit. If this is a 0, address specified by the address bits move the tape to the left; of the instruction. if it is a 1, move the tape Go back to the first step. to the right. Bits 2 thru 7: Next state. These six bits Since the 6800 is a byte oriented machine, are the number of the next the head must keep track of both a byte in state to be executed. memory and a bit within the byte. The

26 December 1978 0 BYTE Publications Inc Tinker, Tailor, Soldier, Sailor .. . Every Chieftain is complete with Doctor, Lawyer ... the Chieftain's here. system software and is totally burned -in as well as tested to further insure high No matter whether you're a serious reliability. hobbyist or a serious businessman, the And it's expandable to 64K memory Chieftain 6800 microcomputer with ca- with up to 2 megabytes floppy disk pabilities that surpass the Z -80 is made storage. for you. So see your nearest Smoke Signal Smoke Signal's quality -packed dealer, he'll be glad to show you how to Chieftain I features two 5.25 -inch mini- get your wampum's worth. Systems floppy drives and Chieftain II fea- start at $2,595. tures two 8 -inch floppy drives. Both microcomputers ,esp4',AN -- ,. 'ts. r, provide 32K static memory, ^y 1 ; ,1 tir Send information on your Chieftain 2 microcomputer two serial I/O ports, a Send name of nearest dealer MHz processor board, a2K ife RAM monitor, a nine -slot w, Name i Address motherboard with built - _ 44t.- 4 in baud rate generator Company r City and gold connectors for high reliability. The State/Zip Chieftain's stylish leather- grained cabinet houses SMOKE SIGNAL the above with its own BROADCASTING cooling fan and regulated 31336 Via Colinas. Westlake Village. power supply. California 91361. (213) 889 -9340 Dealer inquiries invited.

Hail to the Chieftain Smoke Signal Broadcasting, 31336 Via Colinas, Westlake Village, CA 91361, (213) 889 -9340 Circle 320 on inquiry card. BYTE December 1978 27 program uses variable HEAD to point to The logic to test the current bit is: the byte, and MASK to define the bit. MASK consists of seven Os and a single 1. TEST LDX HEAD Load head byte address. The 1 corresponds to the bit under con- LDA B MASK Load bit mask within sideration. For example, suppose the head byte. now points to the third bit of byte 83 BIT B 0,X Test corresponding bit Listing 1: 6800 assembler (hexadecimal). HEAD and MASK would in memory. version of the universal then be: BEQ ITSONE Yes, it's a 1. Turing machine, which im- ITSNOT logic if bit was a O. ITSONE logic if bit was a 1. itates the hardware version HEAD 1 0 0 0 0 0 1 1 (binary) built by Jonathan Millen. 8 3 (hexadecimal) This program is capable The program increments the head position of executing 10,000 uni- MASK \00.___/:101 0 0 0 (binary) (moves tape to right) by rotating the mask versal Turing machine in- 2 0 (hexadecimal) to the right. I f the bit is rotated out and structions per second. into the carry, the HEAD address is incremented. The procedure is similar for moving Hexadecimal the tape left. Address Code Label Op Code Operand Commentary The universal Turing machine program is ORG $0100 stored in the first 128 bytes of memory. PC EQU $FB TURING MACHINE PRO- Each state consists of two 1 byte instruc- GRAM COUNTER tions, so that the instruction's address in MASK EQU $FD SPECIFIES BIT IN HEAD BYTE memory is the state number multiplied by HEAD EQU $FE POINTS TO HEAD OF TAPE 2. The 6800 has no multiply instructions, 0200 DE FE BEGIN LDX HEAD GET HEAD OF TAPE ADDR. but in this case the same effect may be 0202 D6 FD LDA B MASK MASKS OUT BIT ON HEAD 0204 E5 00 BITB O,X IS BITONTAPEO? accomplished by the rotate left instruction: 0206 27 03 BEQ ZEROBIT YES, DON'T INCREMENT PROGRAM COUNTER Before shift 0 01 0 1.0 0 1= decimal 41 state 0208 7C 00 FC INC PC +1 NO INCREMENT PRO- GRAM COUNTER number. 020B DE FB ZEROBIT LDX PC GET ADDRESS OF NEXT I Mill TURING INSTRUCTION After shift 0 1 0 1 0 0 1 0= decimal 82 state 020D A6 00 LDA A O,X GET TURING INSTRUC- address. TION IN REGISTER A 020F OC CLC CLEAR CARRY PRIOR TO TEST Hardware versus Software 0210 DE FE LDX HEAD GET HEAD BYTE AGAIN 'SET HEAD BYTE /MASK UP OR DOWN ONE POSITION IF DIRECTION BIT IS 1 OR 0 Although there is probably not a great 0212 85 40 BIT A #$40 MASK OFF DIRECTION practical need for Turing machines of this BIT type, the two designs provide some insights 0214 27 07 BEQ DEC DECREMENT IF IT IS ZERO into the benefits and costs of each approach. 0216 56 ROR B ROTATE RIGHT IF IT'S A The most significant benefit of the hard- ONE is speed. can 0217 24 09 BCC OK NO CARRY TO NEXT ware approach The program BYTE only process 10,000 universal Turing ma- 0219 08 INX INCREMENT HEAD BYTE chine instructions per second, or 25 percent 021A 56 ROR B SHIFT CARRY THROUGH 021B 20 05 BRA OK ALL DONE of the circuit's capability. 021D 59 DEC ROL B ROTATE MASK LEFT ONE The most significant benefit of the soft- BIT ware approach is its flexibility. For example, 021E 24 02 BCC OK NO CARRY TO NEXT BYTE suppose the address field of the instruction 0220 09 DEX DECREMENT HEAD BYTE 0221 59 ROL B ROTATE THRU CARRY 0222 DF FE OK STX HEAD RESTORE HEAD POINTER 0224 D7 FD STA B MASK RESTORE MASK Hexadecimal `WRITE SPECIFIED BIT ON TAPE Addresses 0226 4D TST A CHECK LEFT BIT OF Use INSTRUCTION 0000 thru 007F 0227 2B 05 BMI WRITE1 SKIP IF IT !SON Universal Turing machine pro- 0229 53 B gram and state storage area. COM COMPLEMENT MASK TO 0080 thru 00FA WRITE A ZERO Universal Turing machine tape storage area. 022A E4 00 AND B O,X 'AND' IN A ZERO 00FB thru 00FC 022C 20 02 BRA BRANCH SKIP AROUND THE Universal Turing machine pro- WRITE -A -ONE LOGIC gram counter address of next state. 022E EA 00 WRITE1 ORA B O,X 'OR' IN A ONE 00FD Tape head mask. 0230 E7 00 BRANCH STAB O,X PUT BYTE BACK TO TAPE 00FE thru 00FF head 'SET TURING MACHINE PROGRAM COUNTER TO NEW ADDRESS Tape address. 0200 thru 0237 6800 program 0232 84 3F AND A #$3F MASK OFF TWO LEFT interpreter BITS (listing 1). 0234 49 ROL A MULTIPLY BY TWO 0235 97 FC STA A PC +1 STORE AS NEW PRO- GRAM COUNTER Table 1: Memory allocation for the software 0237 7E 02 00 JMP BEGIN EXECUTE NEXT UTM implementation the universal Turing INSTRUCTION of machine.

28 December 1978© BYTE Publications Inc More and more, you see the North Star HORIZON computer at work: in business, research, and education. Its high North Star Systems performance qualifies the HORIZON for demanding professional applications. Over 10,000 users during the Go To Work past two years have proven that North Star hardware has the reliability for day -in, day -out computing. The HORIZON is now a serious candidate for any small system installation. SOFTWARE IS THE KEY TO HORIZON MATURITY North Star BASIC and DOS have been used to develop hundreds of commercial program packages. These packages establish that North Star software has the completeness and convenience necessary for serious program development. Because of the many independent vendors offering software using North Star BASIC and DOS, the HORIZON owner now has the widest selection of software in the microcomputer industry! 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BYTE December 1978 29 is to represent a signed displacement from are needed and the computer is usable for the current program counter, as Millen any other projects without losing the ability suggests in his article. In hardware, this to reload the universal Turing machine would require adding a 6 bit adder between program. the address bus and the program counter, This example cannot be taken as a com- plus some temporary latches to hold the plete treatment of the trade -offs of the two results. In software, a store instruction must approaches. Each designer must judge the be changed to an add instruction. In hard- merits of an approach according to the ware, the board must be modified to accom- particular needs of the problem to be solved. modate the new circuitry, and the clock re- If the universal Turing machine were to be adjusted. In software, under MIKBUG, the mass -produced for time -critical operations, change can be made with seven keystrokes. the hardware approach would be best. If If this system were to be widely dis- the design is to be used for the Sunday tributed, complete documentation would afternoon project of a microcomputer have to be written. The hardwired approach enthusiast who already has a system, the requires a circuit board layout, a schematic software approach would be best. diagram, parts list and written commentary. In the software version, comments in the program serve to document the system, along with a written commentary. The software approach allows a building Operating the Turing Machine block technique. The program may be easily combined with other programs. The external 1. Put your program in the state stor- programs need to know only the addresses age area. Note that the address of each of the various blocks in the universal Turing state is twice the state number. machine program's logic. The universal 2. Initialize the tape storage area. You Turing machine circuit would have to be may put your tape anywhere in memory modified to adapt it to other equipment. as long as you set the tape head pointer The software version uses MIKBUG's load to the proper initial address. Location and dump routines to save the tape contents, hexadecimal 0080 is convenient. but this would have to be a specially con- 3. Initialize the program counter. Put structed circuit for the hardwired design. 00 in location hexadecimal 00FB, and the The design, implementation and testing first address in the Turing machine in lo- times of the software version were two, one cation hexadecimal 00FC. This must be the actual memory address (twice the and two hours, respectively. I don't know the exact times required for the hardware state number). approach, but they should be at least several 4. Initialize the mask. The mask se- times more than the software approach. lects which bit of the byte pointed to by In order to build the hardwired circuit, the head pointer to operate on. It must the experimenter must obtain all the cir- be composed of seven 0 bits and a single cuitry, a circuit board, wire, power supply, 1 bit. 01 is a reasonable starting value. etc, which may or may not be used in future S. Initialize the head pointer. This is experiments. However, once you have a the address of the byte in memory to be microcomputer to work with, no extra items considered as the head of the tape. It must point to the tape storage area. 6. Set your MIKBUG start address to hexadecimal 0200, press G (for go), and Function Hardware Version Software Version away it goes. Program storage 2102 Memory locations hexadecimal 00 thru 7F Tape storage 2102 Memory locations hexadecimal 80 thru FF Program counter Two 74161s Memory locations hexadecimal FB thru FC Head Three 74191s, 7474 Memory locations hexadecimal FD thru FF REFERENCES Sequencing 7404,74161,74154 Conditional branching Display 7 segment LED MIKBUG print /punch command 1. Millen, J, "A Universal Turing Machine," Initializing tape 74157,7400,switch MIKBUG load command December 1976 BYTE, page 114. Saving tape MIKBUG print /punch command 2. Ralston, A, and Meek, C (editors), Encyclo- Debugging design Logic probe and MIKBUG break command pedia of Computer Science, Petrocelli- Charter, oscilloscope New York, 1976, pages 1432 thru 1437.

3. Shannon, C E, and McCarthy, J (editors), Table 2: Correspondence chart of the functions of the two approaches and Automata Studies, Princeton University Press, the means with which they are implemented. Princeton NJ, 1956.

30 December 1978 © BYTE Publications Inc Micromotion has done for the 5 -100 bus what IBM did for the floppy disk.

IIIIIIIIIIIIIIII Ill Ill III ,r, IIIII ,.a.1.,,,u - . Il i , ' oo 11 - , .6 tll F l 4.6 : ] 111 ,1 ,.,,, ir!', i- r f.ókilE\ ---il~ ---iiir--- -. tE!`- t.lJ .., , n , ' r-:: - "a,' -,.... `1' .l.-

Double Capacity and the software is oll ready to go. An onboord 2708 EPROM The DOUBLER - Micromotion's latest advance in floppy disk contains the bootstrap. There's even jump -on -reset circuitry technology - doubles the capacity of floppy disk systems. so you con operate without a front panel. And, of course, Over 500 KBytes are recorded on each side of on 8" disk. we include utilities to format diskettes. This means bigger files for more powerful systems. Universally Versatile Double Speed The DOUBLER will operate with all industry- standard mini Doto transfer with the DOUBLER is twice os fast - 500 Kbits and full -sized drives. And it will work in any 8080 or Z -80 per second. And since there is twice as much doto on each S -100 computer operating at 2 to 4 MHz. The DOUBLER will track, your drive steps only half os much - so your system support up to four double or single headed drives. runs foster than it ever has before! Fully Compatible Increased Reliability The DOUBLER is compatible with CP /M* version 1.4. If you That's right even better reliability. Why? Because we did - hove a CP /M* 1.4 system, just odd our CBIOS - or you con it the IBM way. IBM designed 2D formatting - so it hos to buy our ready -to -boot version. Install the new controller, be reliable. Micromotion's innovative, state -of- the -art de- connect any terminal to the RS -232 interface, and boot off sign incorporates write precompensotion electronics and a your new double- sized, double -speed system. You still con phase lock o all S circuit oscillator on single, digital, -100 use oll your old software without any changes. board. So we guarantee the DOUBLER will be more dependable thon your present single density controller - and Completely Affordable we worontee the DOUBLER for a full year. All Micromotion products ore fully assembled, thoroughly Unbeatable Convenience tested, include complete documentation, and ore priced for value: It couldn't be easier to step up to double density. The DOUBLER double density controller $ 495. DOUBLER operates automatically in either single or double MEGABOX dual drive double density system 2,295. density. Just insert a diskette andyou're running properly. You ZEPHER Per Sci double density system 2,595. con transfer files between single or double density diskettes - Z -PLUS - MEGABOX 32 KZ -80 computer 4,295. without any software or hardware changes - or even operate with one single and one double density diskette. Available Installation is o snap. There's o hardware UART on board The DOUBLER is available NOW at your local computer store.

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Where there's always more in store. 'CP/M is o trademark of Digital Research.

Circle 223 on inquiry card. BYTE December 1978 31 Photo 1: Hewlett- Packard 5082 -7340 hexadecimal character display, which uses a

pseudo 7 segment dot matrix. On and off control of the dots at the end of each segment allows the circuit to display capital Bs and Ds. The display pictured is powered.

Ray was referring to an engineering Build an consulting job I had just completed in Acapulco for CBS. The Miss Universe Pageant, which was broadcast live from Mexico, included a new twist this year. A Octal /Hexadecimal computerized judging system. It sounded like a fun consulting job as opposed to the

usual, "design me a computer for . . ."

type. The final rationalization was, I needed Output Display a vacation anyway. I wouldn't want anyone to think that the 70 contestants had anything to do with my decision to go. The other lucky members of our engineering party were Gus Calabrese (formerly

Steve Ciarcia "Steve, I think we have a little problem!" with Digital Group) and George Watson and POB 582 Ray charged into the basement and hovered Dale Walker of CBS. Gus and I main- Glastonbury CT 06033 over me waiting for a response. tained the hardware; Dale supported the

I slowly rotated in my swivel chair. The software; and, while George's official func- rate was barely sufficient to overcome tion was the electrical scoring system, his

static friction, but I finally made it. As I unofficial title was chief taco tester. He had

raised my head to talk I was interrupted. this uncanny ability to sort through all the

"Steve, I think we have a problem with various smells emanating from a restaurant that EROM." Before he could finish, his and evaluate palatability. If he didn't turn expression abruptly changed and almost green as he walked through the door, it was without a pause he ended the sentence Amercianized enough for us to eat there. with, "...what happened to you? You look This smooth sailing trip was punctuated like death warmed over!" by a succession of daily crises. For instance,

I could barely see the person standing George's wife, having thoughtfully packed

before me with his hands on his hips. I also his suitcase without underwear, gave us the experienced a strange sensation of either a hoped for opportunity to take a crash veil covering my face or an advanced case course in Mexican capitalism and to venture of furry eyeballs. Whatever the cause, Ray out to the market place. The cab driver was still standing there awaiting a reply. It who "drove" us there (I use the word was a chore to speak. As the muscles con- loosely) was subject to suicidal fits. From

tracted to produce the necessary air flow, I then on everything went downhill. The list could sense a sudden recurrence of physical goes on and on. Reliving the past two weeks

problems which I had hoped were on the in my thoughts heightened the sense of

wane. physical malaise I was experiencing. Fortu- "Steve you look terrible! You should be nately, Ray spoke again in time to bring me raring to go after two weeks in Acapulco, back to reality. basking in the sun." "What's wrong with you ?"

32 December 1978 © BYTE Publications Inc G/2 MEANS BETTER BASIC, EXCITING COMPUTER GAMES,AND VALUABLE HEALTH HINTS.

Now you don't have to be a pmgrummer to use

The G/2 Program Library is moving into computer stores all over America. These your com uterI reliable, professional programs are pre -recorded on cassette tapes. They contain prompting instructions for easy use, and come complete with a detailed instruction manual. G /2's rapidly expanding library of program topics appeals to a broad range of interests, and every program will help make your computer a better investment. G/2 Basics for SOL and SWTPC (created by MICROSOFT") are far better than the interpreter you're now using. G/2 Stan- dard Basic lets your SWTPC 6800 execute programs faster, uses only 7K of memory, and offers string arrays, extensive string functions, peek, poke, wait, continue, calculator execution, 10 nested subroutines, and much more. G/2 Extended Basic puts the king of Basic interpreters in your SOL computer. It offers string arrays, 16 -digit accuracy, fully descriptive error messages, automatic line numbering and renumbering, an amazing editing capability, trace function, and many additional features you thought were limited to disk -based systems. G/2 Beat the House brings the excitement of casino-type games of chance right into your own home. When you sit down to play Black- jack, Craps, Roulette or Slot Machine, you'll feel like you're in the middle of a Las Vegas casino, playing for big stakes. G/2 Clinic helps you understand the effects of environment,

heredity, personal habits, diet and even biorhythms on your health. Built - in prompts make these three programs easy for your family and friends to use, even if they've never before touched a computer. G/2 Contests for Apple Owners use the full power of Apple's color graphics to simulate the tense dangers of interplanetary war, the hair- trigger suspense of a shootout, and the challenges of several mathematical and pure logic puzzlers. Start building your G/2 Program Library today. For the name of the G/2 dealer nearest you, call us toll -free at 800/538 -1770. (In California, call 800/662-9810.) Then load one of these tapes and put the full power of your computer to work for you. THE REASONKearun YOU BOUGHT YOUR COM TER. IIWTM [RT

A produd of GRT Corporation Consumer Computer Group 1286 North Lawrence Station Road Sunnyvale, California 94086 408/734.2910

Circle 156 on inquiry card. "Let's just say it has something to do successfully fired up my Scelbi -8B 8008

with a guy called Montezuma." microcomputer. Even though I hadn't "You're not supposed to drink...." used it for well over a year, the read only

"Yeah, I know! Don't drink the water!" memory based operating system brought it Ray looked at me and decided his prob- to life immediately. The recognizable lem still needed attention, even though pattern on the light emitting diode (LED)

I was dying. "Steve, I was about to check display indicated it was ready to read input

the EROM contents against the listing you data, so I slapped in the cassette that Ray

gave me when I noticed that it was in octal. had found. Fortunately the data was stored We need to use that EROM tomorrow and in a format acceptable by both machines,

we had better find the error in it tonight. I and totally independent of the processor. I

made a hexadecimal dump of the EROM couldn't execute the Z -80 EROM listing I

contents but I still can't check it against had loaded, but I could display it. your listing." "OK, Ray. Now that we've loaded the The response was obvious. "Why don't data we can step through it on single step you convert it by hand ?" and look at it on this output port display,

"Sure," said Ray, "I can convert it, but which I built a while back."

a thousand conversions is more than I have "How's that going to help ?" Ray looked time for tonight. Can we assemble it in at the 3 character display as he pressed the hexadecimal on your system ?" single step a few times. "The 8008 is an

My temples were starting to throb. I octal machine. Even the data on your hadn't used my computer in three weeks. display is coming out octal." he said.

Nothing was hooked up and I was in no It was hard to smile but I managed a

condition to either attach and fire up my slight variation on the theme as I said, own programmer or write the simple algo- "Flip the switch next to the display." rithm to perform this minor calculation. It Instantaneously, the 257 previously dis- was hard enough for me to remember how played changed to AF, its hexadecimal to operate my own system without ex- equivalent plaining the intricacies to Ray. "Hey, that's not bad, a combination

"Look, Ray, any night but tonight. I've octal and hexadecimal display! All I have got it in octal, decimal, hexadecimal, binary, to do is step through and copy down the

-anything you want, but not tonight. I just hexadecimal equivalents, right ?"

don't think I can hack it. You understand, I nodded and Ray started to write. don't you ?" Barely ten entries had been made when He was disappointed, but being a good his hardware curiosity got the best of

friend he understood. "Can I borrow your him. "I was thinking of putting one of TI programmer and some desk space? A these on my system but it looked like too

thousand entries times five button pushes many components. By the way, I only see

. . . shouldn't take more than an hour or two chips. Where are you hiding the rest ?"

two. Got your battery charger handy ?" "Remind me to tell you when I recover." It seemed a shame to make Ray go to such lengths. If my system were up it would Build a Combination Octal /Hexadecimal take only a matter of seconds to print Display out Ray's listing. It may have been a very powerful Z -80 computer on any other Some people may consider hexadecimal occasion but tonight it wasn't processing displays a trivial addition to an expensive anything. computer system, but sometimes these little

As I reached for the calculator in my add -ons make program debugging easier. I

briefcase I spied a relic that might provide can't help but wonder whether other com- a solution to the problem. "Ray, see that puter experimenters would have need for

rectangular box with all the printed circuit such a display. I don't expect it to replace

boards plugged into the top of it ?" I pointed the video display; but often, when debugging to a bookcase that contained everything but a program, it's nice to be able to display a books. "Bring it here and plug it in, and byte here and there to verify proper program search through that pile of tapes over there execution. It will never replace the stepper

until you find one marked with the same and breakpoint monitor I now use, but

name as your listing. I made a binary dump it's great to display keyboard or 10 data

on tape at the same time I made your quickly with a single output instruction. listing." There are some advantages to being There are many methods to display hexa- ill- letting others fetch and carry is one of decimal numbers on a 7 segment LED.

them. Figure 1 and table 1 show an example of the Relying mostly on Ray's high level of usual brute force method using a read only hardware expertise, interspersed with what- memory as a hexadecimal decoder. Pro-

ever limited verbal input I could manage, we gramming the 82S23 was described in the

34 December 1978 © BYTE Publications Inc Mauston InfTrumenT

-ea -70 -60 -50 -140

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Circle 173 on inquiry card. BYTE December 1978 35 November 1975 BYTE ( "A Versatile Read Fortunately there are other products on Only Memory Programmer," by Peter H the market that can solve the problem. l've Helmers, page 66). While this is a viable been using the Hewlett- Packard HP7340 approach, an excessive number of com- hexadecimal display for a number of years. ponents is needed in this stand alone dis- Those familiar with it can rightfully say how play, and most people would rather not have trivial the solution was, while those who are

to program an E ROM. The alternatives are not may find it a revelation. Photo 1 illus- to allow a computer to perform the de- trates the physical size of the HP7340. A coding and drive the 7 segment display hexadecimal A is displayed in a dot pattern. through the transistors from a latched 8 bit These hexadecimal displays depart from output port, or to put additional logic standard 7 segment format by being capable around a standard 7 segment decoder driver of displaying a capital B and D in hexa- for the extra requirements. The former case decimal. This is accomplished by controlling necessitates a computer program while the the corner dots which give the appearance latter can involve as many components as of "rounding." This ability discriminates a those in figure 1. B from an 8 or a D from a O. There are 16 distinctly different characters. An additional feature of the HP7340 is Input 82S23 7 Segment that it contains a 4 bit latch and the decoder/ Code Program Display driver as well. The result is a single 8 pin hexadecimal display which successfully DCBA d7 d6 d5 d4 d3 d2 dl d0 accomplishes the function of all the circuitry

0 0 0 0 0 1 1 0 in figure 1. The specification of the indi-

0 0 0 1 0 1 0 0 0 0 0 vidual pins are in figure 4. 3 0 0 1 0 0 1 1 0 0 Figures 2 and demonstrate how the HP7340 can be configured to function as a 0 0 1 1 0 0 0 2 digit hexadecimal output port or a 3 digit 0 1 0 0 0 0 0 0 octal port. No 8 bit latch is required since it 0 1 0 1 0 0 0

0 1 1 0 0 0 0 1 1 1 0 1 0 0 0 0 .5 1 0 0 0 0 IK(7) 1 0 0 1 0 0 0 2N2905(7)

1 0 1 0 0 0 220(7) 1 0 1 1 0 0 0

1 1 0 0 0 0 0 1 0

1 1 0 1 0 0 0

1 1 1 0 0 0 0

1 1 1 1 0 0 0 0 FAIRCHILD FND -70 +5 7 SEGMENT LED Table 1: Program for 1C2 in figure 1.

d ICI IC2 7475 82S23 DO e 2 +5 13 4D 40 A3 DI 9 D2 10 12 3D 30 A2 4 D3 3 15 II 2D 20 Al D4 6 +5 16 10 D5 ID 10 AO 7 D6

D7 A4 CS

13 14 15 +5 LATCH E> vENABLE 7404

+5 Figure 1: Hexadecimal latch, decoder and driver using a standard 7 segment light emitting diode (LED). Line CS on 1C2 can be used to perform the blanking operation. This circuit can be replaced by a Hewlett - Packard HP 7340 or equivalent (see table 2).

36 December 1978 © BYTE Publications Inc Considering a Microcomputer? Be Sure to Check Out the Product Offerings of the World's Largest Full Line Microcomputer Company. All Ohio Scientific machines come with microcomputing's fastest full The feature BASIC -in -ROM or on -Disk for instant use. ST6YL/ Minimu Base C2 -4P Challenger I Series Connfguration Price i The Professional Portable by Ohio Scientific Economical computer systems that talk in BASIC. Ideal for hobbyists, students, education and the home. Superboard II - World's first complete system on a board 4K RAM $ 279 including keyboard, video display, audio cassette, BASIC -in -ROM and up to 8K RAM Challenger IP - Fully packaged Superboard II with 4K RAM $ 349 power supply Challenger IP Disk - Complete mini -floppy system 16K RAM $1190 expandable to 32K RAM once em.mIn. now ea... you Ingo.. moeallryy ..ilul pol.e» pnon.l pompul. 4a'IOiaN.nO mYO11ypI . ....^1^++s.+'x+ ;hallenger HP Series conlprr .+ .=1.:,='.:...... Ultra high performance BUS oriented microcomputers for personal, educational, research and small business use. C2 -4P The .. - professional portable 4K RAM $ 598 . ,.. .M.::.7147.74 .,_. ....,»,.,.....:;;.; C2 -8P - The world's most expandable personal machine 4K RAM $ 799 for business or research applications SMIEFIT1RC C2 -4P Disk - The ultimate portable 16K RAM $1464 C2 -8P Single Disk - Ideal for education, advanced 16K RAM $1738 personal users, etc. C2 -8P Dual Disk - Most cost effective small 32K RAM $2597 business system

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Circle 290 on inquiry card. BYTE December 1978 37 Photo 2: Prototype board of the circuit in figure 4. Two similar circuits were built on the same board. When in the hexadecimal mode (shown at left in the picture), the leading digit is blanked. The display at the right shows the octal mode. Each is wired as an independent output port, but the computer sends the some data to both.

IC3 1C HP HP 7340 7340

D d7 1=> 2 d6 F- C

d7 E> d5 C>-- 8 d6 [-_2> A d4 E)s

DECODED L STROBE

IC4 IC6 HP 7340 HP 7340

2 d2 E> d5 C>- C

dl El> d4 B

4 8 d0 (=> d3 C>

Figure 2: Hexadecimal latch, decoder and driver display circuit. IC7 HP 7340

2 Pin d2 C> C Number Function dI E> B 1 Input B 2 Input C B dO 3 Input D o- 4 Blank Control (blank = +5 V) 5 Latch enable (latch = 0 V) 6 Ground 7 +5 V DECODED 8 Input A STRO-BE E 15

Table 2: Pin functions for the Hewlett- *HP 5082 7300 CAN BE SUBSTITUTED FOR HP5082 -7340 IN OCTAL READOUT Packard HP7340 binary coded decimal APPLICATION. 7300 IS NUMERIC ONLY. (BCD) to hexadecimal display. Similar displays are made by Diolite and Texas Figure 3: Octal latch, decoder and driver Instruments. display circuit.

38 December 1978© BYTE Publications Inc SELECT MODE MODE A OCTAL =0 +5 HEXADECIMAL MODE B HEXADECIMAL = I SWI 2.2K

OCTAL p DI 4 ICIO

MOST SIGNIFICANT DIGIT d7 13 8 E> 4B A 14 1 4A SEL HP 7340

10 12 5 d6 E> 3B 4Y II 3A ICB 9 2 6 74157 3Y d5 2B E> 7 ICII 5 3 2A 2Y d4 3 4 d- IB IY 2 IA DIC STROBE B FROM 115 COMPUTER 8 4 A DATA BUS HP 7340 5 13 d3 E> 4B 14 D3 4A SEL IC12 10 12 3 d2 E> 3B 4Y II IC9 3A 9 2 6 74157 3Y CD LEAST dI E>- 2B SIGNIFICANT 5 7 I 1 2A 2Y DIGIT 3 d0 E> IB 8 1 BIA IA STROBE HP 7340 DECODED STROBE E> V

Figure 4: Combination Number Type +5 V Gnd ing an equivalent 267 octal. The same hexadecimal and octal dis- IC1 7475 5 12 binary information is being sent to each play circuit. IC2 82S23 16 8 port; only the switch setting differs. IC3 HP7340 7 6 IC4 HP7340 7 6 Usually these or equivalent displays are IC5 HP7340 7 6 advertised only as hexadecimal displays. IC6 HP7340 7 6 All strictly hexadecimal displays that I've IC7 HP7340 7 6 IC8 74157 16 8 seen contain these same electronics. While IC9 74157 16 8 alphanumeric displays will also work, they IC10 HP7340 7 6 IC11 HP7340 7 6 require extensive scanning logic and are an IC12 HP7340 7 6 overkill for this application.

Table 3: Power wiring table for figures 1, 2, In Conclusion 3 and 4.

I hope this simple circuit will eliminate any frustration you may have in the area of already contains one. The 7340s can simply hexadecimal displays. be attached to the data bus at any other If you have any comments about this or parallel output port and strobed from a any other article I have written, please write chip select decoder. and include a stamped, self- addressed Figure 4 is the circuit of the unit similar envelope. The mail volume has risen to the to the one Ray used. Two multiplexer point where I'm asked similar questions by circuits alternate the input connections to many experimenters. A few of these letters the displays so that when switch 1 (SW1) is will be included each month in BYTE's in the octal position, the circuit performs as "Letters" column when appropriate. figure 2, and when in the hexadecimal One question I'm often asked is whether position, as figure 3. The leading character my introductions are true. So far everything is blanked when in the hexadecimal mode. I've written is based upon actual people or

Two of these circuits are combined in the events. While I take considerable poetic prototype board of photo 2. The left display license in describing the situations, it is not is in the hexadecimal mode showing B7 necessary to invent fiction when experience while the right is in the octal mode display- is often so much more humorous.

December 1978 © BYTE Publications Inc 39 The Age of Affordable Personal Computing Has Finally Arrived.

Ohio Scientific has made a major built -in "immediate" mode which allows breakthrough in small computer technology complex problem solving without program- which dramatically reduces the cost of per- ming! This computer can actually entertain sonal computers. By use of custom LSI your children while it educates them in micro circuits, we have managed to put a topics ranging from naming the Presidents complete ultra high performance computer of the United States to tutoring trigonometry and all necessary interfaces, including the - all possible by its fast extended BASIC, keyboard and power supply, on a single graphics and data storage ability. printed circuit board. This new computer The machine can be economically ex- actually has more features and higher per- panded to assist in your business, remotely formance than some home or personal control your home, communicate with other computers that are selling today for up to computers and perform many other tasks $2000. It is more powerful than computer via the broadest line of expansion acces- systems which cost over $20,000 in the sories in the microcomputer industry. early 1970's. This machine is super easy to use This new machine can entertain your because it communicates naturally in whole family with spectacular video games BASIC, an English -like programming lan- and cartoons, made possible by its ultra high guage. So you can easily instruct it or pro- resolution graphics and super fast BASIC. It gram it to do whatever you want, but you can help you with your personal finances don't have to. You don't because it comes and budget planning, made possible by its with a complete software library on cassette decimal arithmetic ability and cassette data including programs for each application storage capabilities. It can assist you in stated above. Ohio Scientific also offers you school or industry as an ultra powerful hundreds of inexpensive programs on scientific calculator, made possible by its ready -to -run cassettes. Program it yourself advanced scientific math functions and or just enjoy it; the choice is yours.

40 BYTE December 1978 Circle 290 on inquiry card. Ohio Scientific offers you this remarkable jk vies tiltV 13:. new computer two ways. In PUPP o114i =e111r1111e1a irl10110 11141 III hie IL IIJJ4IiF. 1 v, K 16 N 1! I f; 1" 42 IP rrP- NU 1M 1 > - M trs IP. iP r 12 pc C M 1B N r

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Circle 290 on inquiry card. BYTE December 1978 41 WE'RE ALTOS COMPUTER SYSTEMS. Our SUN -SERIES ACS8000 business /scientific computer creates a new standard in quality and reliability in high technology computers.

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[aLr.o.5; Circle 12 on inquiry card.

COMPUTER SYSTEMS UE SANTA CLARA CA yovov (408) 244 -5766 Book Reviews Many games are only the point of depar- ture for exploration by the hobbyist. One could extend many of these to any home built computer. A lot of thought went into The Pocket Calculator Game Book this book and it shows. I think the book by Edwin Schlossberg and John Brockman does the best possible thing for a hobby: it William Morrow and Company Inc makes the hobby more fun. New York 1975

158 pages hardbound Noel K Julkowski $6.95 Naval Environmental Prediction Research Facility Monterey CA 939401 For many of us, the introduction to the microcomputer is the pocket calculator. However, after we learn its functions, it often ends up in a drawer except for shopping and checkbook balancing. It shouldn't. U...oETALERVICE STATEMENT OF OWNERSHIP, MANAGEMENT AND CIRCULATION There are many ways to use your calculator (Requited by 39 U.S.C. 3685) I. TITLE DI . ION A. PUBLICATION NO. for enjoyment. 1. oa or PILING BYTE The Small Systems Journal )j 0 2 4 j 1 l 0 Octc . 29, 1978 ]. PREOUNCV DP IUE . INED NU . CR.PTIDM I like the competitive aspect of this Monthly A " "UALLT12E L ' " "Ea15A /year computer business, either against the I . LOCATION o KNOWN oICE o ULICAT ION (Sln.l. Cllr. COATIy. SI.Ie.nd ZIP Cod./ (Not ',Wen, 70 Main Street, Peterborough, NH 03458 machine or another player. Therefore I like I. LOCATION OP TICE 0EA D OUARTNI OR U11II. OPPICE OF THE ULI (Not PHnbn) those books which show me new games to 70 Main Street, Peterborough, NH 03458 play. In this collection of 50 games, the . L.NAMES ANO COMPLETE ADDRESSES OF PUBLISHER, EDITOR. ANO MANAGING EDITOR P R (Nom. end Address) authors present a variety which will appeal Virginia Londoner, Grove Street, Peterborough, NH 03458 EDITORoR (Nam. end Add)n.. are the to everyone. There applications for Carl T Helmers, Jr., Noone Avenue, Peterborough, NH 03458 "four -banger" as well as the more complex MANAGING EDITOR (Name rd Add,...) scientific models. You can play with one or ].OWNER Of owned by O corporation. IM ne*e end redress mewl be.l.I.dand .Ise Immediately thereunder the none .r olebeeen of.eed- more calculators, and one or more players. holen owning or AalSln. I percent or Mon or 101.0 amount or .loch. )/ real owned be rorpprIbn. the none .Id+drawer of the 666661 owners awl be Vern I/ owned by POrinerAlp or ether unince.Penled film. 11a nome end ddn so wed oe IMI of ..de &,d SW moot You may throw in dice or playing cards for be Ewn.l variety. RID Virginia Londoner M Grove Street, Peterborough, NH There are easy games and hard ones, Carl T Helmers. Jr. Noone Avenue, Peterborough, NH offering a range for all ages. Several have two versions, a simple method and complex one S. KNOWN BONDHOLDERS. MORTGAGEES. AND OTHER SECURITY HOLDERS OWNING OR HOLDING I PERCENT OS MORI OP TOTALAMOUNT OP BONDS. MORTGAGES OR OTHER SECURITIES of Mery e no.., .0 POOP) those you with the costlier machines. for of NAME SS "1001" is one of several games whose object Nnne is to reach a particular number using the fewest moves. Use dice to determine your I. FOR COMPLETION BY NONPROFIT ORGANIZATIONS AUTHORIZED TO MAIL AT SPECIAL RATES SW.l. 116.178. SMI move, and hope for luck. There is ''Calcu- TM t o. ... lunation. and nonprofit IIUIV. of WI. organization ..e dl..rnmt NOON for Peen Weer.. Up PU.e0S(C1,r WIN lator Pokers' with betting strategy to guide HA VE MOT MUNIRA MAY DURING afar . ..nb b/.M .eE- - --E. /PBIg you. For the business minded, there is El PRCEOIMO o MOMTME PRECEDIMI U MONTHS .Dh YbeOhlee&l AVERAGE NO. COPIES EACH ACTUAL NO. COFIN OP SINS.. "Economy" with all the trappings of high O. EXTENT AND NATURE OF CIRCULATION ISSUE DURING PRECEDING ISSUS PUSLISHEO NSAREIT TO IS MONTHS FILINO OATS finance. The student of political science will A. TOTAL MO .COPIEFRINTSO Pie Prow Soo 133,765 139,400 find meat in ''Cold War" or "Detente." D. AID CIRCULATION There are puzzles, mazes and much more. As I. EIMDORRMOCOUMTEREAMDCARRIIRE. 21,469 22,128 a puzzle freak, I found my favorite among L MAILDCRIPTIOM 103,484 110,464 these pages. By multiplying and dividing C. TOTAL PAI0CIRCULATION (Soo ofIOII owl ¡BI)) 124,953 132,595 in a judicious manner, one can deduce the D Amot...COMFL'1 Ile. eMNP OVlee SS 3,423 3,817 proper path to follow. A game is a valuable test to see whether your calculator can It. TOTAL DISTRIBUTION (ERI efC.,d D) 128,376 136,412 P. COPT. HOT OITRIEUTID handle certain operations. This would be an I. u55. LEFT OVER. UNACCOUNTED. SPOILED ORC PR MTIM 3 710 2 , 988 excellent way to check out a calculator that L RTURN FROM NEWS AO.. none Las of today you are considering buying. 1,679 O. TOTAL (HM,, all, PI end 11-enerid616.1 not PnerM.. PhO Throughout the book, the authors offer MA) 1 ,7655 139,400 ill A TL i OP 111 R. PU ES. WORM. samples of how each game should be played, II. I certify that the IEstemeata made by OE MAMA . O To R above are correct sadcoaspkk. as well as winning strategy. In the intro- di (y/ Publisher Il.FOR COMPLETION BY PUBLISHERS MAILING AT THE REOULAR R SS (1.01 . I. le.II YEayl duction are explanations for those concepts 3D U. S. C. MI CrOOM In Wilmot port: NO moon who would her. boon .Rld.e Si I.06 tr.. ow./ 1110+....í1M NN of ON. We which may be new to some readers, such as OW! mall loon manor .í1M room WNOMed under this NW .len tank. M 11b..nlO I IY wed S1. P. S.A. *AT. ROW. M poor... to ma II mRtw N Neon row.. random numbers, and a glossary of hand In I00.ro.nloe with the pIOVlsldns of this R.N. I hero. NO.... P.rmMbn to .n. No 5e1M.000 ,%e, O SON I e Oa Ptad em6) calculator terms. A handy index divides No.. pr.Mn,IC .uM.1Ued On 30 U. S. C. attn. TINA D Poo or ..O. M.N.M.N, N. CN. OR OWN. the games into like categories, such as num- Publisher ber of players, or games with dice, and so / 4 M FOee forth. M.. 19]] 352e (P e 1 ! (Soe bntnlettaM on reverse)

December 1978 0 BYTE Publications Inc 43 COSMAC 711 $249 jets the entire family into creating video games, g and control 111.0. functions. For starters

COSMAC VIP, the completely Soon RCA will offer assembled, ready -to- operate RCA options for color graphics Video Interface Processor, opens up a and 256 tone sound generation. whole new world of computer excitement. New An optional auxiliary keyboard challenges in graphics, games and control will open up an exciting world of two -player functions. Yet it's just $249.00. games. Easy to buy. And easy to program, thanks to Take the first step now. its unique, easy -to -use interpretive language. Check your local computer store or elec- You get a how -to including complete book tronics distributor for the VIP. Or contact RCA programs for 20 games: fun, challenging, and VIP Marketing, New Holland Avenue, Lancaster, ready to load and record on your cassette. PA 17604. Phone (717) 291 -5848. Simple but powerful. 'Suggested retail price. Does not include video monitor or cassette recorder. Built around an RCA COSMAC microprocessor, the VIP is a complete computer system that can grow with you. It has 2K of RAM, expandable on -board to 4K. Plus a ROM monitor, audio tone output to a built -in speaker, power supply, and 8 -bit input and output ports for The fun way control of relays, sensors, or other peripherals. into computers. RC,' 44 BYTE December 1978 Circle 322 on inquiry card. Life With Your Computer

Justin Milliun Judy Reardon entire space at once, in steps. Each of these I 2 3 Peter Smart steps is called a generation. 4 0 6 W Ossipee Rd The rules which determine the state of a Silver Lake NH 03875 given cell in the next generation are what 6 7 8 give Life its delightful properties. They were chosen with great care by Conway, with Figure 1: The center cell reasons in mind that will be discussed later. (0) has eight neighbors, as What can you do with your computer? [For mathematical background information does every cell except After hearing about the game of Life, you see the book, Introduction to Artificial those bordering the edges may never ask the question again. Within the Intelligence by Philip C Jackson, published of the cellular space in any capabilities of a very minimal system, Life in 1974 by Petrocelli-Charter. A discussion finite buffer in a computer gives the computer the kind of job it does of cellular automata and pointers to several program. Treating boun- best: an enormous amount of repetitive detailed references are found in chapter 8.] dary conditions for a finite logical operations. [The authors' system Let us say there is a pattern of cells in the Life buffer is a fine point demonstrates this point: it had 2 K memory cellular space, some living, some not. The of Life program design. and a video terminal at the time of this rules tell which presently living cells survive, writing.] This leaves you, the user, free to which living cells die, and which cells that apply your creative energy on this fascin- are not now alive will be living in the next ating game. generation. The rules are as follows: Developed by John Horton Conway, a British mathematician at the University of Each cell presently alive which has Cambridge, Life was first described in the either two or three of its eight neigh- October 1970 Scientific American by boring cells alive will be living in the Martin Gardner in his "Mathematical next generation. Games" column. Its name comes from its Each cell presently alive which has resemblance to changing societies of living other than exactly two or three live organisms which can grow, move and neighbors will not be alive in the next occasionally die out. generation. If a cell is presently not alive, and The Game of Life exactly three of its eight neighboring cells are alive, it will be living in the 2a An easy way to understand this game is next generation. to imagine an immense gridwork or checkerboard. We call each square in the checker- The above rules are applied all at once in board a cell, and the entire board a cellular the program for the game of Life. Every cell space. Each cell is identical and can perform in the space is checked, as are its neighbors. a number of specific functions. We won't The fate of that cell in the next generation worry about the edge of the board: let's is then determined. Note that this will say the space is large enough so that we amount to many thousands of checks in

never know there is an edge. I n the game of each generation for a cellular space filling Life, each cell can sense its eight neighboring even a small video display screen. 2b cells (as in figure 1). Each cell in our space When the program has been loaded into is in one of two states: it is either alive, or the computer and you've entered the Figure 2: Examples of still not alive (quiescent). The cellular space pattern, what can happen as the pattern life cell patterns, the block changes with time; time advances over the evolves? There are a number of possibilities. (a) and the beehive (b).

December 1978 © BYTE Publications Inc 45 Types of Patterns

I The pattern may die, leaving you with an empty display as you search your imagination for another possibility to try. 00;00 It may stop at what Conway calls a still

life. A simple example (figure 2) is the I block, another the beehive. These patterns, ;I when left undisturbed, remain the same i i generation to generation (a little more inter- ; esting than a blank screen, perhaps). 1 The pattern may develop a repeating cycle. The simplest of these is the blinker, Figure 4: An example of the tumbler, a which returns to its original self every other periodically repeating pattern. generation (see figure 3). A more sophisticated periodically repeating pattern has been described in the February 1971 Scientific Infinite Evolution a Possibility?

American. Discovered by G D Collins J r, it is called the tumbler (figure 4). It has a Conway selected the rules of Life to meet period of 14 generations, but after seven it the following considerations: is an upside -down copy of the original pattern; hence its name. Watching the It should not be obvious that an initial tumbler change, you will notice that in pattern will grow without limit. every generation there is a row of empty (Conway specified that cells can die cells separating two mirror image patterns. from overcrowding.) Each half helps keep the other half under It should seem possible (but not control. If left to itself, half a tumbler will obvious) that some patterns will grow Generation O run over 100 generations before settling without limit. down. Some initial patterns should grow and There are patterns which have most change for a considerable period of intriguing properties of motion. The glider time. shown in figure 5 is one such pattern. It is so named because the way that it moves As reported in the original Scientific is called glide reflection, or reflection from a American series of articles, Conway conjec- diagonal line. In four generations the glider tured that there were no patterns which produces a replica of itself, facing the same would actually grow without limit. At that Generation direction but displaced one square dia- time he offered a $50 prize to the first gonally. After only two generations, it is a person to prove or disprove his conjecture. copy of itself pointing 90° from its original A short time afterwards a group from MIT orientation. There are actually just two disproved it by their discovery of a glider unique patterns in the life history of the gun. The glider gun produces a glider every glider, but it takes four generations for the 30 generations. Since the glider moves away orientation to match that of the original from its birthplace, we may consider the pattern. glider gun to be a special type of repeating Generation 2 Another example of a moving pattern is pattern (see figure 7). The MIT group also the lightweight spaceship shown in figure 6. discovered other remarkable events in Life This pattern also requires four generations by observing such things as collisions be- to move and to complete a full cycle; it tween numerous gliders. also has only two unique patterns if we disregard their orientation. Note that this Symmetry pattern moves along a line of cells, as opposed to the glider's diagonal motion. A rather curious property in the evo- Finally, patterns exist which continue lution of many patterns is their tendency to Generation 3 indefinitely, forever evolving. (It was not gain symmetry. As an example, let us begin certain that such infinite patterns should with a pattern with only partial symmetry Figure 3: Four generations exist for some time after Life was de- called the snowflake, shown in figure 8a. In of the blinker pattern. veloped.) 15 generations it becomes the pattern called

46 December 1978 © BYTE Publications Inc

Generation O Generation I Generation O Generation I

Generation 2 Generation 3 Generation 2 Generation 3 I

Generation 4 Generation 4

Figure 5: Four generations of a glider pattern. Note that Figure 6: This example of a lightweight spaceship in generation 2, the glider is reflected and rotated 90°, pattern also has a 4 generation pattern cycle. Note that moving down one space. In generation 4, the glider is generation 2 is a 90° rotation of generation 0 and is again reflected, but rotated 90° in the opposite direc- moved over one space. In generation 4, the spaceship tion, as well as moved over one space. returns to the orientation of generation 0, but has moved over two spaces.

the honey farm, shown in figure 8b. (This is again an alternative path to the known initial pattern used for producing a honey pattern.) The oscillating period of the Pulsar farm differs from the one discovered by is three generations, and it provides a very Conway and his collaborators.) Within the interesting display. brief history of this pattern, it gains new symmetry it can never lose. Apparently, The "Garden of Eden" unless the pattern dies out completely, symmetry can only be gained, never lost. Up to now, the evolution of patterns has Another example of a pattern increasing been considered, using some initial pattern. its symmetry is given in figure 9. Again, Can this initial pattern itself have unusual beginning with only partial symmetry, properties? It has been proven that a it evolves into another known pattern, so- called "Garden of Eden" pattern must a beautiful oscillating pattern called Pulsar exist for the game of Life. A "Garden of CP 48- 56 -72. It reaches this pattern in 26 Eden" pattern is one which cannot be generations during which it gains its produced by any other pattern. In other symmetry. (The initial pattern given here words, no pattern ever becomes a "Garden

December 1978 © BYTE Publications Inc 47 of Eden" pattern. Such a pattern can only exist, therefore, as an initial pattern specified in generation zero. It has been shown that a "Garden of .. Eden" pattern for Life can exist within a square with 10 billion squares on each side, but possibly it could be much smaller. Perhaps one way to find a "Garden of 00 / Eden" pattern is to apply some programming skill, and all your computer's spare time. You start with a pattern you devised or one your computer generated, randomly or otherwise. The computer could then attempt to find a pattern which generates your pattern by trying out all the patterns possible in a larger space than your pattern uses. If it did not succeed in generating your pattern, you would have found a "Garden of Eden" pattern. A lucky application of this brute force technique may come up with the answer, but the going will be very slow. Perhaps some clever shortcut could be developed.

A Warning

00 The game of Life is downright addictive because there is always another pattern that . you'll want to try out in your search for attractive, unusual or unpredictable patterns. Examining properties of symmetry and motion, and looking for "Garden of Eden" patterns and patterns like the glider gun will test your ability to predict fate in the game of Life.

The Program

A program for Life could be written in BASIC or some other high level language, but it would be grossly inefficient, both in size and speed. First of all, only a single 00 bit is required to store each cell, but there 00 is no simple way to manipulate individual bits in BASIC. You would therefore be forced to use one element of a floating point array for each cell, and since a floating point Figure 7: The glider gun is number typically uses three bytes, you shown in mid-cycle with would only make use of one out of every two generated gliders, the 24 bits. That would mean for a 64 by 64 arrow indicating their cellular array you would need 12 K bytes. direction of travel. A more (Actually, you would need twice this detailed description of this number since two copies of the cellular pattern is given in the array are needed in the simple Life program February 1971 Scientific to be described.) The obvious way to reduce American column by the size is to use every bit; a 64 by 64 Martin Gardner, page 114. cellular array would then require only 512

48 December 1978 ©BYTE Publications Inc I haven't stopped laughing since I read Steve Ciarcia's new book, "TAKE MY COMPUTER ... PLEASE!" Its Steve's first full length book, and it's the funniest to come along in years! It's even funnier if you're into computers! Just one crazy misadventure after another,

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BYTE December 1978 49 C LIFE

ENTER THE INITIAL PATTERN INTO WORKSPACE RI SELECT FIRST CELL Figure 8: The snowflake

1 _1= (a) and the pattern it . - ' generates 15 gener- DETERMINE THE after NUMBER OF ations, the honey farm (b). NEIGHBORS FOR 1i A GIVEN CELL SET THE CORRESPONDING _SO CELL IN _111_0 WORKSPACE *2

I 1 NEW CELL IN WORKSPACE W 2 SAME AS J CORRESPONDING CELL IN WORKSPACE WI Bo

CELL DIES THE- CLEAR CORRESPONDING CELL IN WORKSPACE 2 eb

Figure 9: This seed pattern N SELECT (a) generates NEXT pulsar CP CELL 48- 56 -72. One of the four cycle phases of the pulsar is shown in (b). COPY WORKSPACE 2 INTO . WORKSPACE W I 00 000 DISPLAY WORKSPACE WI t-7- 000

SELECT FIRST CELL IN I WORKSPACE I Figure 10: Flowchart of a Life program. 9 Authors' note: We have written a Life program for the SwTPC 6800 system from ~ 1 :'- =- ':: this flowchart. Our version requires about a 9b 1.5 K of memory for 2000 cell array, and takes only 6 seconds per generation. Our program can be configured for any size array up to a maximum of 2016 cells. Our 6800 Life program can be obtained from The Computer Warehouse Store, 584 Com- bytes. The most efficient way to manipulate monwealth Av, Boston MA 02215.] individual bits is to use assembly language. This will also be about ten times faster than a corresponding BASIC program, due to direct execution. workspace #1. The pattern is then displayed, A general flowchart for a Life program and the procedure is repeated until the is shown in figure 10. The program requires program is stopped. two workspaces, each the full size of the As can easily be seen, Life can be a very desired cellular array. The initial pattern is interesting game. There are certainly moving entered into workspace #1. The program patterns other than those described herein, then creates the next generation in work- and the possibility exists that one of you space #2, since the original generation must reading this could find a previously un- not be altered until the new one is com- known moving pattern. If you make any pleted. After determining the new gener- discoveries while running Life, we would be ation in workspace #2, it is copied back into glad to hear from you. Enjoy Life!

50 December 1978 © BYTE Publications Inc DECEMBER SPECIALS zior- Double density Horizon Kit just announced ... double the storage at the same price! The best buy Just got better. Now, Horizons are double density at the same price as single density. 180K bytes of on -line information per disk! Single density still runs on your new Horizon, or you can copy and convert all North Star software and programs to double density. 160K bytes per disk i Z -80 processor 16K RAM add'1 16K memory, $349 add'i disk drive, $349 Call for low assembled prices. Double exclusive application software density also available on North Star disk sub -system, 5599 kit.

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Circle 226 on inquiry card. ALWAYS THE SAME PRICE FOR VISA & M/C - CALL TODAY! 10 ii u i, 1978 51 You can rely on SCELBI publications. Because Computer info that is fun and exciting. Written and illustrated with YOU, the computer Learn ComputersMicro -

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I "Learn Micro -Computers." Quickly, easily and enjoyably. For the beginner just getting started in microcomputers. Here are all the fundamentals behind the operation of virtually all microcomputers. Everything the beginner needs in one handy package. Contains the popular book Understanding Microcomputers. Written in simple English. Clear. Concise. Accepted as the standard for the neophyte, you must own this 300 -page no- nonsense, easy- reading text. Includes simple -to -use glossary of key microcomputer words. Companion cassette helps you get right into it. Chapter -by- chapter talking synopsis. Key review questions. References to page numbers for further review. You'll gain extra knowledge needed for reading and understanding computer magazines, manufacturer's literature and to feel at home" around computers. A great new idea developed by the computer experts at SCELBI. Get Yours Now! At your favorite computer electronics dealer. Or order direct. Learn Micro - Computers, only $14.95. Paperback edition of book alone: $9.95. Hardcover 52 BYTE December 1978 edition alone: $14.95. Shipping handling extra.* (Available after December 1) they make sense! They're easy to read and understand. For the neophyte. The pro. The advanced wizard. Everyone. hobbyist in mind. SCELBI's Software Gourmet The Z80 Instruction Handbook Guides and Cookbooks for "TAI MY now available! NEW! Your complete guide to the "8080" and "6800" COMPUTIR... Steve Ciarcia's powerful Z80 instruction Now you can cook up PLEASE!" mouth- hilarious new set. This handy, com- watering programs. Delectable computer novel, pact reference pro- "how to" facts include "8080" or "Take my computer vides a clear ex- INS TR, Z80 "6800" instruction sets. How to please!" planation. It's an MANOBOÓK manipulate stacks. Flow charts. An uproariously funny full length ever ready instant Source listings. General purpose book about Steve's true -to -life reference that can for routines multiple precision misadventures and his computer's be carried in your operation. Programming time delays inability to cooperate. Read his pocket. Explains for real time. And much, much off -the -wall attempt to beat the the instruction set more. floating Includes point arith- Jai -Alai system. Or how he attempts in meticulous "8080" metic routines. Specify or a stock market killing but logs detail. Industry "6800 ". Get your copy today! wrong info into his broker's standard mnemonics They're at your favorite computer/ computer. What happens when are used throughout. Machine Or, electronics dealer. order direct. Steve sets up a computerized codes are presented in both octal 8080 $10.95. Paperback: Vinyl: speed trap? And page after belly and hexadecimal format. A con- $12.95. Hardcover: $14.95. 6800, laughing page of nonsense, jollies venient index lists all instructions Paperback only: $10.95. and even illustrations to bring the alphabetically along with machine Shipping /handling extra.* stories to life. 128 pages. Hard codes and timing information. cover. You've got to get yours now! Don't wait. It's available at See it at your favorite computer/ computer and electronics retail electronics dealer. Or, order direct. outlets or direct from SCELBI. $5.95. Shipping /handling extra.* Only $4.95. Shipping /handling extra.* Looking for holiday gift ideas? Give someone the world of computers! Make it a SCELBI publication. They make excellent Christmas gifts. There's one just right for that special someone on your list. I!Sce1bi Publications P.O. Box 133 PP STN, Milford, CT 06460 (a division of Scelbi Computer Consulting, Inc.) (203) 874 -1573 'Prices shown for North American customers. Master Charge. VISA. Postal and Bank Money Orders preferred. Personal checks delay shipping up to 4 weeks. Pricing and availability subject to change without notice. IMPORTANT! Include 75c postage /handling for each book delivered by U.S. Mail Book Rate or $2 for each book shipped First Class or via UPS. Some Facts of Life

David J Buckingham Introduction If an empty cell is surrounded in Computer Communications the present generation by exactly Network Group Life is a game that was developed by three neighbors, the cell will be on E4, room 2369A Prof John H Conway at the University (ie: born) in the next generation. University of Waterloo of Cambridge and first presented by Martin If a cell has no neighboring live cells, Waterloo, Ontario Gardner in the October 1970 "Mathematical or only one neighbor, it dies of lone- CANADA N2L 3G1 Games" column in Scientific American. liness and will be turned off in the The game is derived from a field of mathe- next generation. matics known as automata theory (in this If a cell has four or more live cells case cellular automata). In the February neighboring it, it will die in the next 1971 "Mathematical Games" column the generation from overcrowding. game was described again along with a good introduction to automata theory. These rules are to be applied simultaneously The game is played on a uniform cellular to every cell in the pattern. The application grid (in this case an area divided into of the rules to every bit in the field consti- squares, such as graph paper) where every tutes a generation. See figure 1 for an cell is surrounded by eight immediate example of rule applications. neighbors (ie: cells touching the center cell under consideration). Each cell, or Unresolved Questions

automaton, can be in either a 1 or 0 state (on or off alive or dead). The population What is a unique object in this universe of cells is changed by a set of predetermined of cells? What is a collection of objects? rules. These changes proceed in intervals How do we tell them apart? These are diffi- called generations. cult questions to answer conclusively. The rules are as follows: For the purposes of this article, an object is a cluster of connected bits or cells, a If a live cell is surrounded by two collection of clusters which will cause or three live cells in the present births by being near one another, or a generation, it will remain on (or collection of clusters that prevent some live) in the next generation. birth that would otherwise occur. Figure 2 gives some examples of patterns that would be objects and some that would not. A collection of distinct objects is te- o o o o o o ferred to as a constellation. Some con- o o o o o o o o o o o o o o o o stellations are so common that they are o o named as though they were a single object. Some of these are presented in figure 3.

Figure 1: Transformation of a Life pattern through three generations. This Objects process is sometimes referred to as the automation of the pattern. Generation 0 is the original pattern of live cells. The succeeding generations proceed Most people with access to some sort according to the rules of birth, existence and death. of computer have probably had a chance to observe the variety of patterns that b exist within Life and to note some of the special properties particular to some of these o objects. In order to be able to manipulate o o o o o o 00 o o o o o o o these objects, they have been classified. o o The major groupings of classification are still lifes, oscillators, spaceships, uniform propagators, and a catch -all group of random Figure 2: Example of object contiguity. Group a is considered to be two objects. A rough outline of this system is distinct objects; groups b and c are considered to be single objects. shown in table 1. I shall attempt to describe

54 December 1978 ()BYTE Publications Inc Number of objects Subclass known Smallest object(s)

Class I subdivided by oo block (still lifes) symmetry

(lia1) flip flops blinker (Ila2) on-offs beacon (lib) billiard table >100 MIT oscillator configurations Number of Number of still life Class!! (I lc) inductors 4 tumbler live cells patterns (oscillators) (11d) pulsators 8 mazing, pentadecathlon 1 0 (Ile) shuttles 5 shuttle 2 0 (11f) eater bound 23 two eaters 3 0 4 2 Class Ill (Ilia) diagonal 1 glider 5 1 (spaceships) (Illb) orthogonal 3 lightweight spaceship 6 5 (LWSS) 7 4 8 9 Class IV (IVa) stationary 2 glider gun 9 10 (uniform (IVb)moving 10 25 propagators) 4 switch engine (puffer trains) types 11 46 12 121 Class V subdivided by type bit (single cell) 13 240 (random) of objects in census 14 619

Table 1: Classes and subclasses of objects occurring in Life, along with Table 2: The number of small still life patterns supplementary information. which occur for each number of live cells up to 14.

a b c d

O O O O O O O O O O O O O O O O 00 O 00 O O 0 O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O 00 O O O O O O O O O O O O O O O O O

Figure 3: Commonly occurring constellations. These are not a single object, but bear names for convenience, as follows: a, traffic light; b, honeyfarm; c, fleet; d, bakery.

a b c d e f g h

O O O O 0 O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

O O O O O O O O 6 O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O Ó O O O O O O O O

k m n 0 p

Figure 4: An assortment of still life objects. These remain stable from generation to generation when not disturbed by other objects. They bear names as follows: (top row, left to right) a, block; b, tub; c, boat; d, beehive; e, ship; f, barge; g, snake; h, aircraft carrier; (bottom row, left to right) i, burloaf; j, long boat; k, long snake; I, period 3 eater; m, pond; n, long barge; o, shillelagh; p, hat.

December 1978 © BYTE Publications Inc 55 each class and some of the objects of par- objects that exhibit a flat connected outer ticular note within each class. border that is at least two bits long. Fig- ure 6 shows such an attack. Almost all ob- Class I: Still Lifes jects will develop this type of border if they expand. This property renders the Still lifes are objects in which there are period 3 eater invaluable. Although it is no births or deaths and so remain the same not quite as small as the block, it is still from generation to generation. These par- very much smaller than any other of the ticular objects are fairly easy to enumerate. eater family. An associate of mine, Peter Raynham, The third such object, the period 6 wrote a program which found all still lifes eater, exhibits similarities to the period of less than 15 bits. The statistics of their 3 eater in the way it eats; however it re- distribution are presented in table 2. Some quires six generations to dispose of its of the smaller ones are shown in figure 4. prey and return to its initial state, whereas One of the most practical uses of a still the previous eater takes three generations. life is as an eater. An eater is an object This increase in time is important for suc- capable of destroying or modifying another cess if the object being eaten has left some object and being able to return to its original transient debris near the eater. If the eating configuration. Still lifes are good for this mechanism were to reform itself quickly, since they are able to attack any configura- this debris could kill the eater. In this case,

tion at any phase (they are period 1 objects the eater does not reform for an extra three and do not change). generations, during which time this debris At present we know of three different may well vanish. eaters, each able to attack different types Most of the period 6 eater's prey are the

of objects. By differing objects, I mean same as the period 3 eater's; but both are objects that have different border config- able to attack certain additional objects, urations. Since the eater attacks only the complementing each other very nicely. outside surface of an object, this outer Figure 7 shows the period 6 eater con- surface determines which type of eater veniently disposing of a block. might be suitable for use. Each eater will be described with an object that it can "eat" Class II: Oscillators to show how that eater works. The smallest member of the eater family Oscillators are nonmoving objects with is the block, shown in figure 4a. The block periods of two and greater. A blinker, shown is effective in consuming objects that have in figure 8a, is a simple oscillator consisting one connected bit in the row facing it of three cells alternating in subsequent (as in figure 5). Its other reason for utility generations between a vertical and hori- is the fact that it is very small. In oscil- zontal row. At present, we know of roughly lators and spaceship guns, where there may 150 unique oscillators with a period greater be little room for the removal of spurious than two. debris, there is usually enough room for There is a large undetermined number Note: a block. of period 2 oscillators, since they are very A bibliography containing The second object of this family is the easy to construct. The oscillators have been all Scientific American Life most important and versatile. It is the 7 subclassified by relating their mechanisms articles referred to in text is bit still life referred to in figure 41 as the and their degree of naturalness. (Natural provided at the end of this period 3 eater. This object attacks other objects are those which may evolve from article. random patterns of live cells without intervention by the experimenter.)

0 2 3 Since there are only two basic ways in which a period 2 oscillator can work, these objects are very well defined. Therefore, 0 0 0 0 0 0 0 0 0 0 0 0 0 0 they are assigned to their own subclass o o 0 0 o o o 0 0 o 0 0 0 0 o o O 0 0 o o 0 0 o 0 0 0 0 0 (class 11a). They must work as flip flops, 0 on -offs or a combination of the two. In a flip flop, deaths occur because of under - 0 population. In an on -off, any deaths that 0 0 0 0 occur are due to overpopulation. (This 0 0 0 0 0 0 0 0 0 0 0 0 is almost always true. Figure 9 is a period 0 0 0 0 0 0 0 0 2 oscillator, which if traced, will reveal that it adheres to both definitions.) A 4 5 6 7 variety of small period 2 oscillators is shown in figure 8; the type of each oscil- Figure 5: A block devours a beehive. This process requires seven generations, lator is also given. as shown here. Next in the hierarchy are billiard table

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Circle 225 on inquiry card. BYTE December 1974 57 o i 2

00 00 o o 00 o o o o O O O 00 o O O O O O o Figure 6: The most ver- o o 0 o 6 ob o o o satile eater object, the Ob 0 0 o period 3 eater, devours II I I I I I I I I I IIIII the precursor pattern to a O o o beehive. While in isolation O o a 7 cell still life, this eater O O O O o O attacks other objects with O O O o o o a flat connected outer o o o 00 00 00 border at least two cells in 11[11 III Il II 11111111 length. 4 5

o 2 3 Figure 7: A period 6 eater O O O o attacks and eats a block. o o O o o o o O o O O o o o This new eater is notably 0 O o oÒ 0 o O O o 0.0 o o more than the O o symmetrical o o o O o O o o o O 000 o ol o o period 3 eater. Function- o o-o o o o ally, each complements O O o o O o O O o o the capability of the other. o O O o o o

O O O 0 o O O o O o o o o O 0 0 O o o O O O o O O O O O 000 06 O o 0 o O O o o O O o o O 0 O 00 00 o 00 o o O o o o 0 0 o o o O O

4 5 6

b c d

Figure 8: A variety of small o o o o o o o d o o o period 2 oscillators. These ob- o o o o o o' jects alternate in succeeding O O O O O o o o, o O o O O a generations between two pat- o o o o terns. Those on the top row bear names as follows (left to o o o o o o 0 right): a, blinker; b, beacon; o o 0 o o o c, clock; d, toad; e, bipole; f, o o o o o o O O o o o o o o o tripole; those on the bottom o o o o o row are unnamed flip flops. The o o o o o o 0 0 o o o beacon is the only example here o of an on -off type oscillator. g h

Figure 9: A period 2 oscillator o o oo which functions both as a flip O o flop and as an on -off. O O O o o O o o o o o o o o o o o o o o o o o 00 O O o d o o o o O o o o o o o o o Ó o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o d o o o III010

58 December 1978 © BYTE Publications Inc 'Blaise Pascal

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O '0101 1 Q ,1 ó i l "_-I1 1 . 000ioóóoT I 'V7 'O 1 1 û 1

T 1 1-1- 1 O' O' Í 1 U ! . r.' 00

d e f

Figure 10: Billiard table configurations. These oscillate within on enclosed area, as do bolls on a billiard table. These are artificial objects which have not occurred unless specifically constructed by the experimenter. They tend to be large; the smallest is composed of 18 live cells. Those illustrated bear nomes as follows: a, MIT oscillator (a period 3 object); b, burlooferimeter (period 7); c, an unnamed period 8 object; d, wovefront (period 4); e, an unnamed period 5 oscillator; f, on unnamed period 9 object.

a b c

T- Qt Qo Öa iUÚii O ! ----o-1° aßiii a Oó O

-. Ord ): O0 -- 000 C)

V = . . . . . , . U U 0. . 0 . . . 4 rnr. , :--ri

d e

Figure 11: Inductor and pulsator oscillators. These are natural objects which may appear from automation of random patterns. Inductors possess on imaginary line of symmetry which pulsators lack. They are called by the following names: a, pulsar (on inductor of period 3); b, tumbler (period 14 inductor); c, an unnamed period 8 inductor; d, pentodecothlon (pulsator of period 15); e, mazing (period 4 pulsator); f, unix (period 6 pulsator). The pentodecothlon is of particular historical significance.

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BYII. Uc.emtkr 1918 61

0 configurations (class IIb). These oscillators metry between them (exhibiting one -way are configurations that oscillate within an or two -way orthogonal symmetry). Pulsators enclosed area, like balls on a billiard table. (class IId) are also so far considered to be Billiard table configurations are considered natural oscillators except that they do not to be very artificial, since they have not have this line of symmetry. One of their turned up in the histories of any random properties is that they require no external

objects. By this, I mean that if live cells stimulus to continue oscillating. are placed randomly on the plane, the pat- The aforementioned subclasses have

terns which they generate probably will greatly similar characteristics, so I have never evolve into an artificial object, such grouped them together. Most of the initial as a billiard table configuration. oscillators that were found were from this They are quite large, as evidenced by group, since the methods for harnessing the examples in figure 10. The first example random objects into oscillators were not is the smallest such object, and it consists known at the time. of 18 bits. This subclass of oscillators con- Some of these oscillators are presented tains the only known examples of oscillators in figure 11; the most important of these with periods of 7, 10 and 11. is the pentadecathlon. This object throws The next class, inductors (class 11c), off several sparks (small collections of dying are natural oscillators that exist in two or bits) that can be used to reflect a glider, four pieces with an imaginary line of sym- reflect two gliders, turn a glider into a block, turn a block into a glider, etc. Some of the early research into Life probably might not have occurred if this object had not o been discovered. o o o o o o o o Shuttles (class Ile) are important for the a 0 O O o O O O O existence of much of the interesting re- d O { o o search into Life. Shuttles are objects that o o move back and forth with a relatively large period. The two primary shuttles, the basic shuttle and the more complex a twin bees, leave debris at their extremities 0 0 0 0 O O o o o o 0 0 which would fatally wound the shuttles o o o o if the debris were not removed before they returned (see figure 12). This is one of the uses of the eaters that was discussed in the o o o o o o o o o o section on still lifes. In the examples I have o o o o o o used blocks to remove the debris from the o ends, but just about any of the eaters would have suited some phase of this debris. The debris left behind may at first seem to be Figure 12: Shuttle objects. Object a is the basic shuttle; object b is the twin somewhat of a bother, but without it there bees shuttle. These move back and forth with a relatively long period. Eaters would most likely not be any known glider are used to remove debris from their path. guns (defined later). The very last class (class 11g) contains These a b eater bound oscillators. oscillators consist of patterns which generally must o o be manipulated in order for the object o o o o to return to its initial state. In figure 13 o o o o d o o o O O o O O O 6 o aa a good example of two eater bound oscil- O O O o lators is given that also shows the differ- o o o o o O o o o -0 O o o o o o entiation between two eaters acting on the o o same object (which is not often possible). 0 010 O 10 O 0 0 o lo A period 52 oscillator (figure 14) is shown o o o o o to illustrate the unusual properties of ob- o o o o o o o o o o o o o jects being eaten. The center object will o o o o o o o o o o o o o be attacked by one eater twice each time o o o o it rotates (the object rotates 90° every 13 o o o o o generations). The example in figure 15 is a period 6 oscillator using the period 6 eater. The 7 bit eater is not suitable here Figure 13: Two eater bound oscillators. These differ in that they are stabi- because it would have returned to its original lized by two different eaters. Oscillator a has a period of 6; oscillator b has a state too soon and would have attacked period of 5. the reforming object. (If the 7 bit eater

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Circle 26 on inquiry card. BYTE December 1978 63 is used, the patterns results in two blinkers, first contains static patterns that produce six blocks, and one tub in 110 generations.) moving progeny, and the second contains moving patterns that produce some type Class III: Spaceships of stationary or moving output.

Regrettably, there have been no new Spaceship Guns spaceships reported since the orthogonal spaceships presented in Scientific American Class IVa consists of spaceship guns. in 1971. These are summarized h figure 16. These objects eject projectiles of class III The glider (figure 16a), which features objects. The main two objects of class IVa diagonal movement, has been used for are the glider guns of primary period 30 and many simulations and constructions. 46. There are no primary guns which pro- Movement by an object of one space duce any of the other three spaceships. in one generation is referred to as move- However, such a mechanism can be built ment at the speed of light (c). There is no using glider guns. distinction made between diagonal and The period 30 glider gun (figure 17) orthogonal movement, even though alge- works by having two shuttles of the type braically the distances are not the same. presented earlier aimed at one another. The glider travels at c/4 and the three The debris that would normally be removed other spaceships travel at c /2. The interest- by eaters collides and just happens to create ing thing to note is that the three larger a glider that escapes without harming the spaceships travel orthogonally. The ortho- shuttles. The period 30 glider gun is of gonal spaceships are most useful in several paramount importance to simulations in Life of the types of puffer trains to be discussed and the possible existence of computing in the next section. mechanisms. These implications will be discussed in a later article. Class IV: Pattern Producing Mechanisms The period 46 gun, known as a newgun, also works by having two shuttles collide. Class IV is divided into two sections: the It may be seen in figure 18. In this case the shuttle consists of two B heptominos (described later) travelling opposite one another to produce debris at both ends of O 0 0 0 travel. A glider is produced when these two O O 0 shuttles, which are of the twin bees type, O 0 O collide at right angles. There are other O O O 0 arrangements of this shuttle that produce gliders in other ways, including an ambi- O O O dextrous variety. Figure 14: A long period eater O There is another interesting variation: O bound oscillator. This object if one of the debris removing blocks is O O O O has a period of 52; 13 gener- O O removed from the end of one of the twin ations are required for 90° of O 0 O bee shuttles, the gun will still work. rotation. The central section is 0 0 O O O O attacked twice by one eater O Puffer Trains each time it rotates. Puffer trains are patterns that move and leave debris in their wake. Because these patterns do move, as opposed to the sta- O tionary spaceship guns, they are not only 0 0 0 0 able to produce moving debris but also o 0 O O 0 0 O trails consisting of stationary objects. Leav- o O 0 0 0 0 0 0 0 ing stable objects is useful when the inten- 0 0 O 0 O tion is to produce a train of puffers to build O O O some sort of construction on the fly. 0 O O three basic trains all O O The puffer work O O O by different means. The train which was O O discovered first is presented in figure 19. O O O O O O The center object is a pre -B heptomino, Figure 15: A period 6 oscil- O O O O 0 which, if traced, will seem to move forward the O O O O O O lator which employs period O O O until the debris in the back of it stops the 6 eater. This matching of O O O O O O O uniform forward motion. In this case, O O period frequencies prevents the the B heptomino is bounded by two light- O O eater from disrupting the re- O weight spaceships able to control the object; forming central group. the whole configuration puffs along at c /2.

64 December 1978 0 BYTE Publications Inc This object reaches a stable period of 140 a b c d after a startup time of over 1000 generations. Additional spaceships may be added 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 to the end of the object to further adjust 0 0 0 0 0 0 0 0 0 0 the output from it in order to reduce the 0 0 O 0 0 0 final period, the startup time necessary O O O to reach a stable period and to adjust the output to blocks, gliders, etc. A type of puffer similar to the previous Figure 16: The four known spaceships which occur in Life. Their appellations one is called a Schick ship (after its dis- are: a, glider; b, lightweight spaceship; c, middleweight spaceship; and d, coverer). This is an interesting object (con- heavyweight spaceship. The glider travels diagonally at a rate of one space sult figure 20) in that the "engine" is really every four generations. The other three travel orthogonally at one space a tagalong, an object capable of being per two generations. pulled along behind another object (usually a spaceship). Here, a heptomino follows a pair of mirrored spaceships. It is quite remarkable that this configuration leaves 0 0 0 0 a small trail of debris behind it and that, 0 0 O O O O O O O although this debris would die if left alone, 00 0 0 0 O additional spaceships following behind are 00 0 O O O O O O 0 0 0 0 0 able to trigger the debris into varying forms 0 0 0 of static debris. The static debris can be 0 0 left behind and used later. It is relatively useful for building armadas because of the relative simplicity of creating this object Figure 17: This glider gun, which has a period of 30 generations, was the from gliders (producing a basic ship requires first object of class I Va to be discovered. It periodically emits a glider which 11 gliders). travels away diagonally. The four block still lifes are used as eaters to dispose The last type of puffer train is the small- of debris. Glider guns are of great importance in simulations, where gliders are est, a mere 11 bits at startup - the size is made to collide, thus forming new objects. somewhat larger when the final repeat cycle is known, since there is transient debris in the field. This particular train travels very slowly, taking 96 generations to a traverse eight spaces (speed c/12). It is also a a a - very unusual in that it is the only known -o puffer train that travels diagonally - the a o -0 o same direction as the glider, but three times as slow. o o Unlike the other puffer engines, this 0 train does not require that any other space- 0 0 o ship exist to bound it. To stabilize the basic engine, a block must be placed somewhere in the debris produced by the object to prevent the debris from destroying it. If 0 0 0 0 0 the engine is run without a stabilizing block, 0 0 0 0 some rising debris finally catches the engine 0 0 after 11 full cycles and destroys it. The 0 O remaining field settles down to a final O 0 0 O census only after 3911 generations! Pertinent to the above paragraph is the fact that random patterns are quite often able to produce certain types of edge configurations, which enable them to surge forward with a great burst of speed for short periods of time. In the case of the switch engine, when some random exhaust manages this type of movement, this slow moving 0 0 0 0 engine is easily caught. O O O O The switch engine (presented in figure 21) will produce, after its startup time, eight blocks every 288 generations. Other Figure 18: A period 46 glider gun which is called the newgun. Two twin debris can be produced, including gliders. bees shuttles collide at right angles to produce one glider every 46 gen- Since this train travels so slowly, there are erations. As before, the block still lifes are used to remove debris which presently no real uses for it. could cause disruption of the formation.

December 19780 BYTE Publications Inc 65 130013ooa 000 Class V: Random Objects o0000 A random object is simply anything O0130131M 130 (ANNE that does not fit in any of the above classes. 0 It appears that all random objects eventually become something from one of the above Figure 19: A puffer train constructed from the precursor to a classes. It has been assumed that there B heptomino and two lightweight spaceships. After a startup are no objects that expand irregularly period of over 1000 generations. it stabilizes into a period of forever (this is a common problem in other 140 generations. cellular spaces using other rules). There are some very popular nonterminals in life, which, due to their commonality, have been Figure 20: A Schick ship puf- 0 0 0 0 0 0 given names. In some cases these have been fer train. The engine in this 0 0 0 0 rather heavily investigated. In figure 22 are object is pulled along behind 0 0 0 0 some of the more common nonterminals and another object. In this exam- 0 0 0 0 their names. ple, a heptomino tags along The most common object of this class behind a pair of mirrored 0 0 0 0 must be the oft publicized R pentomino spaceships. This object has a 0 0 0 (figure 22a), which many people still believe period of 12. runs forever. The result of this pattern was, however, published in Scientific American; it runs for 1103 generations, producing four blinkers, eight blocks, one boat, four 0 0 beehives, one ship, one burloaf, and six 0 0 0 gliders. 0 0 0 The B heptomino (figure 22b), with a census of three blocks, one ship and two gliders in 148 generations, is one of the more heavily investigated objects, as is evidenced by some of the material presented in this Figure 21: The switch engine puffer train, with a basic period article. It has the following interesting of 96. After startup, it produces eight blocks every 288 property: the front configuration of the generations after the initial stabilization of debris. Although object moves along to reappear the same much various debris may be created with this train, its slow every other generation, but flipped over. speed limits its usefulness. A close relative of the previous object

is the 77 heptomino (figure 22c) with a census of five blinkers, six blocks and two Figure 22: Several com- a b ponds in 173 generations. Phase 1 of this mon random nonterminal object was called a blasting cap by the objects. These are desig- 0 0 0 00 0 0 0 artificial intelligence researchers at Massa- nated as follows: a, R 0 0 0 0 chusetts Institute of Technology (MIT); pentomino; b, B hepto- we call phase 3 a house. If you trace the mino; c, 7r heptomino; and 0 0 0 0 house for 30 generations, you will notice d, acorn. The acorn is a 0 0 0 that a house reappears at the front of the Methuselah type object. 0 0 0 0 0 0 0 debris ten spaces ahead of where it started. Finding all the descend- d The house does not appear again after this ants such an object is a of because the debris catches up with it and challenge. difficult kills it. Many attempts have been made to stabilize this object, with no success as yet. About the Author A random object that consists of fewer than ten bits and that has descendants David Buckingham is an undergraduate science student at the Univer- enduring for more than SO generations is sity of Waterloo. He made a number of contributions to the now defunct referred to as a Methuselah. The acorn publication Lifeline. Most of these had to do with oscillators, which con- pattern (figure 22d) is presently the record stitute his main field of interest in Life. He has at present found over 100 holder for duration. This is presented as a oscillators of periods greater than two. challenge to anyone who would like a difficult object to trace. Buckingham's most productive area of research has been the devising We hope that some of our investigations of glider collisions to produce objects of classes I thru IV. As of August into the more exotic corners of Life will 1978, he has managed to create collisions to produce all of the presently inspire readers to try their hands at this known 1105 objects of less than 15 bits in size. fascinating pastime.

66 December 1978 © BYTE Publications Inc Early issues of BYTE carried a never article on the subject, including defi- completed series by Carl Helmers inad- nition of the several varieties of vertently entitled "LIFE Line," which spaceships. January 1971: pages 105, 106 and 108. was also the name used for Robert Continued progress on the Life front Wainwright's newsletter. These Helmers including answers to several unsolved articles appeared as follows: questions and results of a flurry of computer Life activity. February "Mathematical "LIFE Line 1," September 1975 BYTE, 1971: Special Games" article on "cellular automata volume 1, number 1, pages 72 thru 80; The January 1979 "LIFE Line 2," October 1975 BYTE, theory." March 1971: pages 108 and 109. Short issue of BYTE will con- volume 1, number 2, pages 34 thru 42; "LIFE Line 3," December 1975 BYTE, note about progress made by John tain an article by Mark Conway and R William Gosper, plus volume 1, number 4, pages 48 thru 55; Niemiec which de- illustration of a large scale flip flop "LIFE Line 4," January 1976 BYTE, scribes several algo- pattern which is delicately balanced volume 1, number 5, pages 32 thru 41. and easily destroyed by minor disturb- rithms for Life. Readers ances such as impact of a glider. who wish to experi- April 1971: pages 116 and 117. Examples ment with Life patterns of fuses, the 5 cell cross series, and will find these algo- announcement of Robert T Wainright's Lifeline newsletter. rithms useful in writing A bibliography of Scientific American November 1971: page 120. Short note efficient Life programs information on LIFE (all references are on continued progress at the MIT Al for their computers. Laboratory. Gardner's to Martin `Mathematical January 1972: page 107. The discovery Games" column). of the eater by Bill Gosper at MIT.

October 1970: page 120. This is the original Hurry down to your public library if Life article, including the definition of you wish to use these references, as due the facts of Life, and illustration of to lack space some local libraries may numerous fundamental patterns. of November 1970: page 118. Answers to be committing the unspeakable crime of several questions posed in the first throwing away Scientific American ....CH

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December 1978 ® BYTE Publications Inc 67 One -Dimensional Life

Jonathan K Millen PhD 661 Main St Concord MA 01742

The game of Life is known to many com- appeared in three of the earliest issues of puter experimenters for its beautiful, sym- BYTE ( "LIFE Line 1, 2, and 3," BYTE Sep- metrical two -dimensional displays and for its tember 1975, page 72; October 1975, page imaginary population of blinkers, beehives, 34; December 1975, page 48). It is an attrac- gliders, and other strange, pseudoliving or- tive home computer software project, but ganisms. Invented by the British mathema- the program requirements in memory capa- tician John Conway, the game was described city, processor speed and display capability

in the "Mathematical Games" section of were more than I possessed in my homebrew Scientific American in October 1970 and machine. The programming effort also

February 1971. A series of articles on how looked formidable. I developed One- Dimen- Figure 1: The state of a to program it for a home computer also sional Life as a small scale substitute. cell in the next generation Conway's Two -Dimensional Life traces is computed from its pre- successive generations of a pattern of cells in sent state and the states of CELL X TO BE RECOMPUTED an infinite square array of cells like an un- the four other cells in its colored checkerboard. The generation rules neighborhood. The neigh- determine the state of a cell in the next gen- ROW Y I Y X I Y I Y I borhood of a cell consists eration based on its present state and the of all cells within a dis- states of its neighbors, the eight cells touch- -i tance of two cells from i ing it. the cell in question. NEIGHBORHOOD OF CELL X Each cell has two possible states: off and

(a) III III II Il II II n 0

(b) I I . ' ' IIII I11 I 1010

Figure 2: The generation rules, illustrated here for a few representative cases. Each cell is marked with a dot if it is on, and left as an empty square if it is off. The next generation of the middle cell in each neighborhood is shown below it. 2a illustrates the rule that a cell is "born" if and only if it has two or three on neighbors in its neighborhood (in each example, the square being examined is shown in color). 2b illustrates that a cell survives if and only if it has two or four neighboring on cells. Note that a cell dies if it has three on neighbors.

68 December 1978© BYTE Publications Inc on. A cell is "born" (ie: goes on when pre- A glider is shown in figure 6. It looks the viously off) if exactly three of its neighbors same in every generation, but in each genera- are on. A cell survives (ie: stays on) with tion it moves one cell to the right. It is easily two or three neighbors on. Otherwise it is proved, incidentally, that One -Dimensional off in the next generation. Life, unlike Two -Dimensional Life, has no stable patterns that repeat in one generation Generation Rules in the same place. In a one- dimensional version, patterns have to exist in a single row of cells. Each

cell in the row has two cells touching it. I GENERATION tried all possible generation rules involving a cell and its two neighbors, and I was disap- IIII* *IIIII pointed in the results with all of them. It finally occurred to me to try a larger neigh- 2 borhood including not only the adjacent II lei II0III cells but also the two adjacent to them (see l figure 1). It still took several tries to come 3 up with generation rules that seemed to I I 1.101 I 1 I I yield a game approaching the richness of the two -dimensional game. The rules illustrated Figure 3: The simplest oscillating pattern, consisting of two adjacent cells on. in figure 2 met my criteria for interest, Three generations are shown. Every second generation recreates the original which included the existence of oscillating pattern, so this pattern is said to have period 2. Its alter ego, the pattern with patterns with long periods, patterns with two cells on separated by two cells off, also has period 2. The three genera- long lifespans that eventually vanish, and tions are separated in order to emphasize that they are separate generations gliders. The rules can be summarized as fol- rather than part of a Two-Dimensional Life configuration. lows: Each cell is viewed with respect to a 5 cell region including itself and two neighboring sights on either side. Cells with two or GENERATION three neighbors on are born and those with two or four neighbors on survive. The rest 2 are off in the next generation. 3 The bare rules are rather plain without some biological "facts of life" to dress them up. The following explanation is offered: Figure 4: A pattern with period 2 that oscillates between the starting pattern and its image. These kinds patterns are sometimes called flops Rule 1: Birth. Cells that are off but mirror of flip in conventional Life terminology. (Note that each line is the complete state have either two or three neighbors on, the Life universe in one generation.) go on. of

Rule 2: Survival. Cells that are on and have two or four neighbors on stay on. GENERATION Those with zero or one neighbors on die from loneliness; those with three neighbors on die from overcrowding. 2 What keeps a cell with four neighbors 3 on from dying is not clear. Maybe 4

there is just not enough room to lie 5 down. 6

Examples 7

Let us trace the life spans of a few patterns. The simplest oscillating pattern con- Figure 5: A line of five cells that regenerates itself after six generations. In my sists of two adjacent cells on. Its next gener- experience, this pattern has the longest period of any One -Dimensional Life ation has two cells on with two cells off in pattern. between, and the third generation regenerates the original pattern. Figure 3 shows three generations of this pattern. Note that GENERQT/ON the successive generations of a one- dimen- sional pattern form a two -dimensional 2 pattern. 3 Another period 2 pattern is the flip flop in figure 4. A line of five adjacent cells on is also periodic, but with period 6. Seven gen- Figure 6: A glider pattern, so called because it regenerates itself in a steadily erations of it are shown in figure 5. moving position. This glider has a period of 1.

December 1978 © BYTE Publications Inc 69 We have seen a glider of period 1 and two interacting, the pattern as a whole will not static oscillating patterns of periods 2 and 6. repeat until the twelfth generation, because Are there patterns with all possible periods? 12 is the least common multiple of 4 and 6.

I generated the life spans of lines with up to What about odd periods? Having found a

15 cells and found one new oscillating pat- glider of period 1, I tried a number of similar tern: a line of 12 cells that oscillates with but longer patterns and discovered the pe- period 4. This suggested that static oscillat- riod 3 glider shown in figure 7. Readers ing patterns could be found for even periods, may enjoy discovering for themselves an-

though I have not yet found any with pe- other period 3 glider that is one cell longer riods longer than six. Of course if one starts than the one in figure 7. It is tempting to a line of 12 (period 4) and a line of five (pe- conjecture that gliders exist with all odd riod 6) far enough apart to keep them from periods. If anyone finds oscillating patterns

or gliders of period 7 or greater, I would like to hear about it. GENEAATON Tabulation

is an 2 There obvious notation for specifying a pattern without drawing a picture. A 3 one -dimensional pattern, being just a se- 4 e. e. quence of on and off cells, may be regarded as a binary number. By convention, we can Figure 7: A glider that moves right by one cell every three generations. It has consider the pattern proper as just the cells length 8; there is another period 3 glider of length nine. The two intermediate between the leftmost on cell and the right- patterns of this glider are, of course, also gliders of period 3. most on cell, inclusive. Thus, the number for a pattern will always be odd, except for the "all off" pattern, O. Pattern numbers can be reported in decimal, octal or hexadecimal to Pattern Number Fate save space. For example, the first generation Hexadecimal Binary (patterns referenced by hexadecimal) shown in figure 3 (two adjacent cells) can be represented by binary 11 (or hexadecimal 1 1 Dies after generation 1. 3 11 Oscillates with period 2. 3). The second generation in figure 3 would 5 101 Dies after generation 2. then be represented by binary 1001 (or 7 1 1 1 Becomes number 1F after generation 1. hexadecimal 9). The pattern of binary 11111 9 1001 Oscillates, second form of number 3. (hexadecimal 1 F) goes through the following B 1011 Oscillates with period 2. cycles, all noted in hexadecimal: 6B, 17D, D 1 101 Oscillates, second form of number B. F 1111 Becomes number 33 after generation 1. 49, 1 B, 55 and back to 1 F. (Note the 3 -digit 11 10001 Dies after generation 2. hexadecimal number 17D, which is needed 13 10011 Oscillates with period 2. because the figure is nine cells wide at that 15 10101 Oscillates, fourth form of number 1F. in 17 10111 Glider with period 1. point the cycle.) 19 11001 Oscillates, second form of number 13. This numbering system also provides a 1B 11011 Oscillates, fifth form of number 1F. handy way of enumerating patterns in a 1D 11 101 Glider with period 1. systematic sequence. This gives rise to the 1F 1 11 11 Oscillates with period 6. idea of constructing a dictionary of patterns 21 100001 Dies after generation 1. 23 100011 Becomes number 19 after generation 1. in numerical order, listing for each pattern 25 100101 Becomes number D after generation 1. its vital statistics: whether it oscillates, 27 100111 Becomes numbers 3F,DB,2B5,FF,37B,A05,201,0. glides, dies or leads to a noninteracting col- 29 101001 Becomes number B after generation 1. lection of oscillating patterns and gliders. By 2B 101011 Becomes numbers 3D,31,13. 2D 101101 Becomes number F after generation 1. way of illustration, the first 28 entries in 2F 101111 Becomes numbers 23,19. such a table are shown in table 1. 31 110001 Becomes number 13 after generation 1. Theoretically there is also the possibility 33 1 10011 Oscillates with period 2. that a pattern may grow in mass (ie: the 35 110101 Becomes numbers 2F,23,19. 37 110111 Becomes numbers C7,BF. total number of cells on) without bound, (BF is glider with period 3.) like the glider gun found for Two- Dimen- sional Life. No such infinitely growing pattern has yet been found for One- Dimen- sional Life. Implementation Table 1: Vital statistics of the first 28 One -Dimensional Life patterns. The convention used for identifying the patterns is to regard the pattern as a bi- The discoveries of the period 4 pattern nary number: on cells are represented by ls, and off cells by Os. Only the and the large period 3 gliders were made cells between the leftmost and rightmost on cells, inclusive, are considered, on my Turing machine computer. Imple- and a binary (or hexadecimal) number can then be generated to represent menting the One -Dimensional Life rules was the pattern. easy and would probably have been easier if

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Circle 309 on inquiry card. BYTE December 1978 71 DIRECTION OF SCAN

NEW GENERATION OLD GENERATION

CELL BEING RECOMPUTED

I ( \ CELL ROW N-2 N - I N N+I N+2

I /

NEIGHBORHOOD OLD OLD OLD CELLS USED TO

N -2 N - I N RECOMPUTE CELL N

T2 TI TO

Figure 8: Calculating the next generation in One -Dimensional Life. The algo- states of cells N - 1 and N - 2, together with rithm uses a row of cells and three temporary cell variables. Each cell has one the present states of cells N, N + 1 and N + of two values: 0 for off and 1 for on. Each cell is a bit, a byte, or a word, 2. The old state of N - 2 may then be for- whichever is most convenient in the programming language to compute the gotten and the scan moved right one cell. algorithm. The states of the cells are recomputed in a scan from left to right. I will spare you the details of how this Cells behind the front of the scan have already been recomputed; those ahead algorithm can be accomplished in Turing of it still have their old states. As the algorithm scans from left to right, it machine language. A more universal problem must temporarily remember the old states of each cell long enough to com- is how to get the patterns displayed. My pute the new values of its two neighbors to the right. (Similar temporary only output device, at first, was a single LED value storage problems arise in conventional Life programs.) (light emitting diode) that could be stepped through memory, to display it one bit at a

time. To improve on this I built a visible

I had had a more conventional computer to shift register, a cascade of two 8 bit shift re- work with, instead of Turing machine (see gisters with an LED on each output, giving

"A Universal Turing Machine," December me a movable 16 bit window on memory. I 1976 BYTE, page 114). The algorithm for was considering extending the window to 32

producing new generations according to the bits when I was lucky enough to get a long rules is illustrated in figure 8, visualizing the term loan of a SwTPC CT-1024 video dis- memory requirements, and figure 9, a flow- play from a friend who had no present need chart. Note that, as in Two -Dimensional of it. Life, there is one complication to bear in There is a coincidental resemblance be- mind when computing the next generation: tween a Turing machine and a video display: When you change the state of a cell, you both normally change memory addresses by must remember the old state long enough to ± 1. It turned out to be easy and natural to use it in computing the next state of its patch in the CT -1 024 memory in place of neighbors. If the program scans the row the Turing machine "tape" memory. Turing from left to right, changing cells as it goes, machine computations were then directly it needs a temporary memory of three cells. visible as they progressed on the video When the front of the scan is at cell N, the screen. One more refinement was all that program is able to recompute cell N, after was needed to display successive generations saving it, using its memory of the prior of a pattern below one another as in the

72 December 1978 © BYTE Publications Inc COPUTER SOFTWARE For Homeowners, Businessmen, Engineers, Hobbyists, Doctors, Lawyers, Men and Women Wehave been in businessforovernine years building a reputa- Virtually Machine Independent - these programs are writ- tion for providing a quality product at nominal prices - NOT ten In a subset of Dartmouth Basic but are not oriented for any what the traffic will bear. Our software is: one particular system. Just in case your Basic might not use one of our functions we have included an appendix in Vol- Versatile as most programs for multiple modes of - allow ume V which conversion algorithms for 19 different operation. gives Basic's; that's right, just look it up and make the substitution for Tutorial - as each program is self prompting and leads you your particular version. It you would Ilke to convert your through the program (most have very detailed instructions favorite program into Fortran or APL or any other language, contained right in their source code). the appendix in Volume II will define the statements and their parameters as used In our programs. Comprehensive as an example our PSD program not only - Over 85% of our programs In the first five volumes will execute in computes Power Spectral Densities but also Includes FFT's, most 8K Basic's with 16K of free user RAM. If you only have 4K Inverse -transforms, Windowing, Sliding Windows, simulta- Basic, because of its lack of string functions only about 60% of neous FFT5 variable data sizes. etc. and as a last word our our programs In Volumes I through V would be useable, how- is: software ever they should execute in only 8K of user RAM. Readable - as all of our programs are reproduced full size For those that have specific needs, we can tailor any of our for ease in reading. programs for you or we can write one to fit your specific needs.

Vol. I Vol. II Vol. Ill VDI. IV VoI.V Vol. Vi Business & Games & Binomial Beam Billing Bingo Andy Cap Ledger Maintains Company accounts and generates Personal Pctures Chi -Sq. Cony inventory Bonds Baseball financial reports. Includes routines for Pyn, Fry Bookkeeping Coen Filter Payroll Bull Door A /R, A/P Animals Four Compare Programs Confidencel Fit Risk Enterprise d 10 Astronaut Confi Vol. VII Confidence 2 Integralfon 1 Schedule 2 Football Des rip Bond Bagel Conelaitons Integration 2 Shipping Funds) Dtrter Chess Designed to challenge the average player Building Blo Cycle Curve Intensity Stocks Funds 2 Engine tally comprehensive. Great fun tar all. Oilers a Compound Cannons Differences Lola unique opportunity for beginners in need of an Cyclic Switch Go-Moku Fourier Checkers Dual Plot Macro Jack Horse opponent. Declsl on 1 Craps Exp -Dlsrl Max. Min. Life integers Decision 2 ght Least Squares Navald Medbl I For Doctors and Dentists alike, a complete Depreciation loans Logic Goff Paired Optical Mazes Playboy patients billing system which also permits the Efficient Judy Plot Planet Poker Primes maintaining of a patient history record. Flow Line Up Plotpts PSD Popul Probal installment Pony Wdproc Wordprocessing for lawyers. publishers. writers. Polynomial Fit Rand 1 Profils hterest Roulette Quodrac etc. Write. store, and change from rough draft Regression Rand 2 Subic Red Baron investments Sky Diver to final copy In a variety of formats. Statt Solve Rates Regression 2 Mortgage Tank Stat 2 Sphere Irian Uglily Disk utility program with memory testing. Optimizo Teach Me Retire Road Runner T- Distribution Stars Order Savings Roulette Unpaired Track SBA Santa VOI. Pert Tree Pictures VIII Variance) Triangle Pc -Toc -Toe Rate A Newman Stall() 1040 -Tax Taxpayers return, itemized deductions or J.F.K. Variance 2 Variable Stattl Return 1 standard XY Vector Steel Return 2 Linus Ms. Santa Top Balance Reconciles bank statements Schedule 1 APPENDIX A Nixon Vary Checkbook Balances your checkbook Noel Noel Xmas Nude Insti o 78 Computes real cost on bank financed Items, Peace APPENDIX B cars. boots. etc. Policeman Deprec 2 Computes depreciation, 4 methods. any time Santa's Sleigh period Snoopy Virgin APPENDIX C - FAVORITE PROGRAM CONVERSIONS

Vol. $39.95 Vol. $24.95 $24.95 ill- Vol. IV Vol Vol. Vi $49.95 VIII $19.95 I- WI.II- Advanced Business -$9.95 y -$9.95 - Vol. Vil - $39.95 VOL - Bookkeeping Math/Engineering Billing, inventory General Purpose Experimenters Program Mini-Ledger Professional Homeowner's PloBhg /Statistics Programs Programs Games ants Pictures Bask. Statement Def. Pare

AVAILABLE AT MOST COMPUTER STORES Aaa $150 per volume hanating. oil domestic shipments sent U. PS. except APO Master Charge and Bank Amerlcard ana PO. Box which go parcel post. Foreign orders add 58.00 /volume nor air accepted. shipment and make payable in U.S. dollars only Our Software Is copyrighted and may not be reproduced or sold. 10% discount on purchases of four or more volumes. Offer expires January 31, 1979. SCIENTIFIC RESEARCH PO. Box 490099 -B Key Biscayne, FL 33149 Phone orders call 800- 327 -6543 Information - (305) 361 -1153 BYTE December 1978 73 BEGIN

Figure 9: Flowchart for the One-Dimensional Life INITIALIZE algorithm. N =1 TI =0 T2 =0

TO = CELL(N)

SUM =T2 +TI sCELL)N +I) +C ELL)N +2)

YES NO

BORN: DIES: CELL (N) =1 CELL(N) =0

Photo 1: One -Dimensional Life display. On the

author's system, 1 s are represented by excla- SHIFT: mation points and Os by DISPLAY T2 = TI CELL ROW blanks. Each line repre- TI = TO N=N+1 sents one generation of One -Dimensional Life.

figures: up and down cursor control. Out- puts were created by decoding the last three instruction address bits, effectively yielding / i!i ii eight 1 bit output ports that were strobed !! every time an instruction with the appro- 1 1 ! 1 1 priate address was executed. Two of these 1 11 11 1 outputs became cursor control outputs. 111 111 After all this hardware activity and some 111 111 program modifications, the result was the 11111111111 kind of display shown in photo 1. The screen has the first 16 generations of a line of seven cells. This pattern settles down after 40 generations to a collection of non - interacting oscillating patterns, but before that happens it produces one of the most

intriguing displays of its kind, one that I would never have seen without the help of a home computer. Of course, readers can verify these discoveries with any home computer and share in some of the excite-

ment of exploration which I found.

74 December 978 © BYTE Publications Inc Software for the Percom LFD -400 Disk Operating and File Management Systems

INDEX" : The most advanced Disk Operating and File Management System available for the 6800. INterrupt Driven EXecutive operating system features file -and- device- independent, queue- buffered character

stream I /O. Linked -File disk architecture, with automatic file creation and allocation for ASCII and binary files, supports sequential and semi -random access disk files. Multilevel file name directory includes name, extension, version, protection, and date. Re- quires 8K RAM at $A000. Diskette includes numerous utilities $99.95 MINIDOS -PLUSX: An easy to use DOS for the small computing system. Supports up to 31 named files. Available on ROM or diskette complete with source listing. $39.95 Basic Interpreters and Compilers SUPER BASIC: a 10K extended disk BASIC interpreter for the 6800. Faster than SWTP BASIC, 9 -digit accuracy, program CHAINing, BASE O subscripting, PERCOM's ssembled and Tested improved error reporting, disk data files, and print column alignment. Program and data files may be prepared using one of the Text Editors described FLOPPY DISK SYSTEM below $49.95 BASIC BANDAID": Turn SWTP 8K BASIC into a re- D)=Q1 spectable random access data file disk BASIC. In- cludes many speed improvements and program CHAINing. When ordering, specify version (2.0, 2.2, or 2.3). Complete with listing. $17.95 shipping STRUBALT" : A STRUctured BAsic Language Com- paid piler for the serious professional programmer. In- cludes elements of BASIC, PL /M, and assembly language. Features 10 -digit floating point, strings, scientific functions, and 2- dimensional arrays. Requires 16K RAM memory and LINKING LOADER (see below). The LFD -400 is ready to plug in and run Complete with RUN -TIME and FLOATING POINT packages $99.95 the moment you receive it. Text Editors Nothing else to buy! Not even extra memory! EDIT68: Hemenway Associates powerful disk -based YOU GET: text editor. May be used to create programs and data Q The popular Shugart SA 400 minifloppy'" drive. Drive alignment files. In addition to SEARCH, CHANGE, DELETE, and is double checked by PerCom before shipment. MOVE functions, EDIT68 supports MACROs which Q The drive power supply -fully assembled and tested. perform complex repetitive editing functions effi- Q LFD -400 Controller /Interface -plugs into the SS-50 bus ciently. Runs in only 6K RAM. "Spooling" permits text accommodates three 2708 EPROMs fully assembled and tested. files much larger than the available RAM memory to be Q MINIDOS'" -the remarkable LFD -400 disk operating system on created and edited. $29.95 a 2708 EPROM plugs into the LFD -400 Controller card no extra memory required no "booting" needed. TOUCHUP": If you already have the TSC Text Editor, Q Attractive metal enclosure. TOUCHUP will convert it into a disk -based text editor. Q Interconnecting cable -fully assembled and tested. ROLL function permits text files much larger than the Q Two diskettes -one blank, the other containing numerous available RAM memory to be created and edited. software routines including patches for SWTP 8K BASIC and the TOUCHUP is supplied on diskette complete with TSC Editor /Assembler. source listing. $17.95 Q 70 -page instruction manual - includes operating instructions, ASSEMBLERS schematics, service procedures, and the complete listing of PERCOM 6800 SYMBOLIC ASSEMBLER: Requires MINIDOS'". QQ Technical Memo updates - helpful hints which supplement the only 8K of RAM memory to assemble programs with manual instructions. to use 200 labels. More convenient than most as- ® 90 -day limited warranty. semblers; assembly options may be specified at time Minifloppy is a trademark of Shugart Associates. of assembly. $29.95 MINIDOS is a trademark of PERCOM Data Company, Inc.

Complete listing of above assembler $29.95 The LFD -400 is readily expanded to either two or three drives. MACRO -RELOCATING ASSEMBLER: This Hemen- Write for details. Send for our free brochure for more informa- way Associates assembler is for the programming tion about the LFD -400 Floppy Disk System and LFD -400 professional. Generates relocatable and linkable ob- software. facility nested To save you money, the LFD -400 Floppy Disk System is available ject code. MACRO permits macro only from PerCom. Because of the special pricing, group and calls. Permits conditional assembly. Requires 16K dealer discounts are not available. RAM $49.95 MC and VISA welcome. COD orders require 30 %deposit plus 5% handling charge. Allow three LINKING LOADER for STRUBAL and the above as- extra weeks if payment is by personal check. The LFD -400 Floppy Disk System is available immediately. Allow three weeks for testing and transportation. Texas residents add 5% sembler $19.95 sales tax. Business Applications TM GENERAL LEDGER SYSTEM $199.95 FULL -FUNCTION MAILING LIST $ 99.95 Write or call for our complete software catalog. PERCOM DATA COMPANY, INC. Dept B 318 BARNESGARLAND, TX. 75042 PERCOM DATA COMPANY, INC. Dept BP 318 Barnes Garland TX 75042 (214) 2723421 (214) 272-3421 PERCOM" `peripherals for personal computing'

Circle 301 on inquiry card. BYTE December 1978 75 laws for birth, survival and death to the hogpacncning Quickies present generation. These laws are: Birth: An unoccupied square becomes occupied if in the preceding generation exactly three of the William Englander eight neighboring squares were 1966 Titus St occupied (squares that touch San Diego CA 92110 horizontally, vertically or diagonally are said to be neighboring squares). The game of Life was developed by John Survival: An occupied square remains Horton Conway and was introduced in the occupied if in the preceding Life "Mathematical Games" section of the generation two or three neigh- October 1970 Scientific American maga- boring squares were occupied. zine. Life is played on a grid of squares (in Death: An occupied square becomes this case a 22 by 22 matrix). A given square unoccupied if in the preceding is either occupied or empty. The program generation fewer than two or user specifies which squares are occupied more than three neighboring initially. squares were occupied. The game of Life program produces new generations of the matrix by applying life's Text continued on page 82

BASIC-E COMPILER VER 1.4 1: DIM A(22,22),ß(22,22) INPUT 'ENTER INITIAL NUMBER OF ITERATIONS'DL 3: PRINT 'ENTER INITIAL COORDINATES; 0,0 TO END' 4: 5: 10 INPUT X,Y 6: IF X +Y =0 THEN GOTO 20 7: IF (X::1)0R(X >20)OR(Y:1)OR(X::20) THEN PRINT 'ERROR RE- ENTER': G0T0 10 8: x =x +1: Y =Y +1 9: A(X,Y)= A(X,Y) +10 10: FOR XW=.X -1 TO X +1: FOR YW =Y -1 TO Y +1 11: A(XW,YW)iA(XW,YW) +1 12: NEXT YW: NEXT XW 13: GOTO 10 14: 15: 20 Lf ='+ 16: INPUT 'ENTER PAPER SIZE (IN LINES /PAGE)r SET UP PAPER 8 HIT ENTER'iP 17: FOR I =1 TO L STEP 2 18: 19: PRINT Lf

20: FOR Y =1 TO 22: PRINT ' 'i: FOR X =1 TO 22

21: IF A(X,Y) <10 THEN PRINT ' i ELSE PRINT 'C1'i 22: B(X,Y) =0

23: NEXT X: PRINT : NEXT Y 24: PRINT Lf 25: FOR J =25 TO P: PRINT: NEXT J 26: 27: FOR X =2 TO 21: FOR Y =2 TO 21 28: AW= A(X,Y)

29: IF (AWÇ:.3)AND(AW < >13)AND(AW <: >14) THEN GOTO 30 30: B(X,Y)= B(X,Y) +10 31: FOR XW =X -1 TO X +1: FOR YW =Y -1 TO Y +1 32: B(XW,YW)= B(XW,YW) +1 33: NEXT YW: NEXT XW 34: 30 NEXT Y: NEXT X 35: 36: PRINT Lf

37: FOR Y =1 TO 22: PRINT : FOR X =1 TO 22

38: IF B(X,Y) <10 THEN PRINT ' 'i ELSE PRINT 39: A(X,Y) =0

40: NEXT X: PRINT : NEXT Y 41: PRINT Lf 42: FOR J =25 TO P: PRINT: NEXT J 43: 44: FOR X =2 TO 21: FOR Y =2 TO 21 45: BW= B(X,Y)

46: IF ( BW. <::3)AND(BW;:.13)AND(BW< >14) THEN G0T0 40 47: A(X,Y)= A(X,Y) +10 48: FOR XW =X -1 TO X +1: FOR YW =Y -1 TO Y +1 49: A(XW,YW)= A(XW,YW) +1 50: NEXT YW: NEXT XW 51: 40 NEXT Y: NEXT X 52: NEXT I Listing 1: BASIC E program 53: 54: INPUT 'ENTER NUMBER OF ADDITIONAL ITERATIONS'iL and sample run of the game of 55: IF L: >0 THEN GOTO 20 Life. A sequence of eight states 56: STOP 57: END of Life demonstrates oper- 0 ERRORS DETECTED ation of the program.

76 December 1978 © BYTE Publications Inc MICROPRO INTERNATIONAL CORPORATION

11MICROPRo MicroPro International Corporation..

SUPER -SORT© WORD- MASTER© The ultimate in high performance sort/merge The last word in text editing Specifications Specifications High Performance Tournament/Heapsort Algorithm Compatible with any "Dumb" CRT Possessing Ad- Multiple Input Files Read in Parallel for True Merge dressable Cursor and Backspace (Includes Hazeltine - Operation. Up to 32 Sort and 32 Merge Input Files Handled. All Models, SOROC, Lear Siegler, IMSAI -VIOC, ADDS EDynamically Invokable User Exit Routines Regent, Behive, etc.) Record Selection via SELECT /EXCLUDE Statements Bi- Directional Word Tab, Line Tab, Screen Tab Handles Fixed and Variable Length Records Bi- Directional Word Delete, Line Delete and Character EHandles Fixed and Variable Length Fields Delete Handles up to 32 Sort Keys with Intermixed Sequence Quad -Directional Cursor Movements Indicators, Data Types and Alternate Collating Sequences Mid -Line Insert and Delete Handles Multi -Volume Diskette Files Automatic RAM /Diskette Buffering With No User Compatible with CP /M* and any Derivative Including Intervention ADOS, IMDOS, CDOS, etc. Nested Command Looping with Conditional Execution 8080/8085/Z -80 Compatible Global String Search, Global String Replace Specialized OptimizationsforFloppy Disk Environment Scratch -Pad Buffer for Text Movement, Global Keyword Command Input for Easy Operator Entry Replication, and String Command Storage Benchmarked at Over 560 Records per Minute! Multiple Input File Merging with User -Controlled Invokable as a Subroutine from FORTRAN, COBOL Insertions for Easy Document Assembly and Assembler Multiple Output File Control by Section Under User Furnished in Relocatable and Executable Form for Control Easy Load -Address Definition Compatible with CP /M and Most of its Derivatives Optional TAGSORT Operation Including CDOS, IMDOS, etc. Data Types Include ASCII, EBCDIC, Binary, BCD Elise TEX* for Print Formatting Functions (COBOL Packed Decimal), etc. Supports CP /M- compatible Diskette Files under Price $150 ** includes manual and single density diskette. BASIC, FORTRAN, COBOL and Assembler. Manual only $9.00 refundable with purchase.

'CPIM and TEX are Trademarks of Digital Research. Price $250 ** includes manual and single densitydiskette. " Prices and Specifications subject to change without notice. Manual only $15 refundable with purchase. © 1978. MicroPro International Corporation. All rights reserved.

Dealer Inquiries Invited: Call (Northern California) (707) 544 -2865, (415) 398 -7062, (209) 445 -0511, (408) 279 -8980, (916) 485- 7619 (Southern California) (213) 224 -1619, (714) 634 -2908. Outside California Call Collect (707) 544 -2865. Principal offices located at 5810 Commerce Blvd. Rohnert Par 9. ' 8 Circle 224 on inquiry card. Listing 1, continued:

RUN LIFE BASIC -E INTERPRETER - VER 1.3 About the Author ENTER INITIAL NUMBER OF ITERATIONS? 8 ENTER INITIAL COORDINATES; 0,0 TO END William Englander is a 8,10 self-employed computer ? 9.10 ? 10,10 programmer as well as an 11.10 instructor at San Diego 12.10 + 0.0 State University and ENTER PAPER SIZE (IN LINES /PAGE). SET UF' PAPER 8 HIT ENTER? 33 National University.

[]E]E]E]E] JJV WHAT 0 WE KNOW

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Finally, an objective look at the top 24 micro systems sold throughout the world' ONLY Honest pros and cons of each system, plus a straightforward look at the micro computer $450 industry as it relates to you! PER VOLUME Written in plain English for the layman. If you are considering the purchase of a personal computer, this book will save you money! SAMPLE CONTENTS Don't Get Hung up on the Chips Now, about,, the hardware What? No software! Helpful suggestions before spending money READ UP ON COMPUTERS BEFORE YOU PUT YOUR MONEY DOWN! ONLY $4.50 PER VOLUME TELEPHONE TOLL FREE: 800- 327 -6543- or send this coupon!

5 C...%/ j

78 December 1978 ® BYTE Publications Inc Our Two Bits Bit Pad Bit Pad Bit Pad Bit Pad Bit Pad Bit Pad Bit Pad Bit Pad Bit Pad Bit Pad Bit Pad Bit Pad

Bit PadTM is the low -cost digitizer for small computer systems. Better than a joystick or keyboard for entering graphic information, it converts any point on a page, any distance into its digital equivalents. It's also a menu for data entry. You assign a value or an instruction to any location on the pad. At the touch of a stylus, it's entered into your system.

Who can use it? Anyone from the educator and the engineer to the hobbyist and the computer games enthusiast. The data structure is byte oriented for easy compatibility with small computers, so you can add a power supply, stand alone display, cross -hair cursor and many other options.

Bit Pad by Summagraphics. The leading manufacturer of data tablet digitizers. Bit Pad. The only words you need to say when considering digitizers.

$1,000 creativity prize. Just write an article on an original Bit Pad application and submit it to any national small- computer periodical. If the editors publish it -and the decision is solely theirs -Summagraphics will pay you $1,000.

... 11811 1. .., ...r..-.. II..- .. I.1...\. .. corporation 35 Brentwood Ave.. Box 781, Fairfield, CT 06430 Phone(203) 384 -1344 TELEX 96 -4348 Dealer inquiries invited Circle 356 on inquiry card. BYTE December 1978 79 Listing 1, continued:

Here comes another high -flying Blue Board of Happiness from SSM. The VB -2 Video Board ... it saves programming time, memory space, and is built to U.S. video standards. Check out all our VB -2's great features, and compare prices: It's an I/O controlled Circuitry provided to video interface that drive a speaker for turns a TV or commer- external "beep" cial grade monitor into tone a video terminal 64 x 16 character No need for another display includes up- I/O board for key- per case letters, num- board input and video bers and symbols display Characters can be Hardware controlled switch selected for cursor for line feed, white on black, or carriage return, and black on white backspace Full interlace for com- Reduced software plete compatibility overhead frees up with video stan- more memory space dards for important data S -100 compatible Extra adjustments include adjustable character width, horizontal margin and vertical position

All for only $149.95. Available at over 10100 retail locations, or direct from SSM.

nnnn nnnD E] nnnn n n n SSM manufactures a full line of S -100 boards. For complete details, E]E]E] r, just send for our new FREE catalog. E]

2116 Walsh Avenue Santa Clara, CA 95050 (408) 246 -2707

We used to be Solid State Music. We still make the Blue Boards.

80 December 19780 BYTE Publications Inc Circle 335 on inquiry card. ITHACA AUDIO THE OEM MARKETPLACE

1978 ITHACA AUDIO IA Expands Mass Storage at S-100 Line Incomparable Video Field- proven Prices. Display reliable engineering Over 10,000 boards worldwide prove Ithaca Audio provides the quality and reliability you Ithaca Audio Board demand. Featuring a full 128 upper /lower case ASCII Floppy Disk character set stored in a 1K buffer memory. Ithaca Audio Boards are fully S -100 Easy to read 16 line x 64character format can compatible, featuring gold edge connectors be displayed on an inexpensive video monitor and plated-through holes. All boards (except Up to 250K bytes, single sided the Protoboard) have fully buffered data and or a modified TV set. Includes a TTY software Up to 500K bytes, double sided address lines, DIP switch addressing, solder driver. Add our powerful K 2 FDOS to create a Data protect versatile operator console. mask and parts legend. Powerful software operating Z -80 CPU Board Most powerful 8 bit central system includes 8 utility $25.00 processor available Featuring power-on- programs, text editor. Jump, rovision for on -board 2708. Accepts most 8080 software. $35.00 Add the capacity of full size disk to your S-100 microcomputer. Controller, Disk Drive, and BK Static RAM Board High speed static memory Software available separately. Disk at the lowest cost per bit. Includes memory protect /unprotect and selectable wait states. Memorex single sided Controller $25.00 550 Flexible Disk Drive $456. 2708/2716 EPROM Board Indispensable for stor- Memorex double sided ing dedicated programs and often used soft- 552 Flexible Disk Drive $530. Board ware. Accepts up to 16K of 2708's or 32K of 2716's. $25.00 Disk Controller Board $35. Controls up to 4 single or double sided drives. K2 FOOS Available on 8° Data protect features include automatic Protoboard Universal wire -wrap board for de- disable of write -gate during power -down for veloping custom circuitry. Accepts any size floppy disk w manual $75. data integrity. Supported by a reliable DIP socket. $25.00 software package, K 2 FDOS and complete diagnostic documentation. Quality Components

$35.00 ZILOG Z -80 $19.00 ZILOG Z -80A 23.00 INTEL 2708 11.00 FAIRCHILD 2102 LHPC 1.60 K2 FAIRCHILD 2102 LIPC 1.35 IMSAI 8080 Kit with 22 Slot M.B. Operating $560.00 plus 51000 shipping System RAM ! HOW TO ORDER Power full disk software in the DEC tradition. Send check or money order. include $2 00 shipping per order Includes Text Editor (TED), File Packagge (PIP), 32K for $359. N Y S Residents include tax Debugger (HDT), Assembler (ASMBLE), 4115 HEXB1N, 1 COPY, System Generator (SYSGEN). Ithaca Audio is now stocking the Mostek Command syntax follows Digitals OS -8 RT/11 add -on RAM for S.D.'s Expandoram. Buy their For technical assistance call or write to. format. First in a family of high level software. basic board, 32K of RAM from us and SAVE. Soon to be released, FORTRAN & Pascal Compilers. S.D. SALES Expandoram board $199 ITHACA Ithaca Audio 32 4115's @ $5.00 ea. $75.00 32K Only AUDIO $35 P.O. Box 91 Ithaca, New York 14850 Phone: 607/273 -3271

Circle 190 on inquiry card. BYTE December 1978 81 Listing 1, continued:

alpha 111 micro E]E]E]

E] E] 16-bit world of Alpha E7 E] See the exciting [7 E] Micro at your local Alpha Micro dealer. nnn

ALABAMA CONNECTICUT NEBRASKA WASHINGTON HUNTSVILLE HAMDEN OMAHA BELLEVUE CompldeVand JR V Cempuler Shore Byle Shop &l Byte Shopal 12051539 -1200 (2031 281-1453 14021 339.7350 12061748 -0651 Omaha SPOKANE ALASKA FLORIDA 59 oa ANCHORAGE CORAL GABLES 14021592 -]590 + + DeleCom SunnyY omputer 15091 7474135 507134 Inc :l05; 66nc :305; ComputerLAS MILWAUKEE MILWAUKEE FORT LAUDERDALEDERe C, Systems + + ARIZONA 30517524965Ie 170 R3-74 The Mrlwaukee PHOENIX H0LEAH 5 C141259r :lore Byte SRS- M1 RENOBEND 14141259.9140I41AI 259.920 16021 (702 Sto-ol WYOMING TEMPE CFm- 8leral50 (7021828 -8080 Byte 967.141 eas JACKSON -4m Teto1 Dale Systems TUCS967.1421 MIAMIMIA IIEWJERSEY 13071703 8313 TUCSON Byte 564- ISELIN Campuler Marl al Byte SKapol 1305)264-2983 ARGENTINA (8021327 -4579 12011283 -0800 BUENAS AIRES HAWAII CALIFORNIA HONOLULU NEW YORK Markel Se NEW YON BERKELEY Pan Peptic AUSTRALIA Byte Shop al Cempuler Computer Marl of -8388 1212)888 -7923 E] 0151945 Company TMaDIaOPauBc CARSON (808)737 -5857 NORTH CAROLINA 499 -8708 E3 Shaw Brothers Smal Computer BOONE WEST PERTH (2131770-3888 Syalema Alpha MOM Syalema Aualrallan Camwler [] COSTA MESA 1800) 732 -5248 170412úA -7948 Orange CaunIV 1091 322-6497-0497 IDAHO NEWELL 1091322 Digital DMam7a ALICE SPRINGS E]E]E] E]E]E] (714)646-0221 BOISE (7041374-1527 Mer ocampuler FRESNO Caprle1O11ice :y ElecInc Brain Mactunes. Inc OHIO Alicee rin 1209)227 -8479 Camputeroivruon CINCINNATI EJ 12íI013.2.8585 NORTH FREMANTLn GLENDALE Digital Deapn MClaRyB San E3 Beaunarc -6733 ILLINOIS 15131581 35 -4677 12131 244 -9348 E- CHAMPAIGN CLEVELAND NORTH SYDNEY U JOLLA Byte Snap al Kn9away Tech -Marl Champaign CFmpulera COm- ulerCa 12181333 -3181 929 -9901 17141459 -2797 (217) see-mai COLUMBUS LAWNDALE Midwapern Dgllal BELGIUM CICERO Byte Snap El E OSAn BRUSSELS 0191131 Research 12131371.2421 (1141 294-2991 13121856 -3353 MANHATTAN BEACH (021 519-9093 De Merle -Shatz EVANSTON OREGON Computer Syslema IOy Billy BEAVERTON CANADA Machine Ca 12131 545-4539 BRIeYIO Shope! TORONTO MISSION VIEJO 13121328 -eeoo (503)844 -2888 The Campuler Race 741770- end Sala UMBURG EUGENE 14181 598-0262 Date Domain al 17141770 -001 Real Oregon QUEBEC ORANGE (312)397 -8700 Campuler Ca Trais- Rwieres Seim Inc Compiler Man INDIANA (5031484-1040 (7141 633.1222 BLOOMINGTON PORTLAND 819373 -23B7 OXNARD oela Domain Byle Shapal VANCOUVER Text continued page 76 APR Syslema -3498 Byle Shoo al from 18121 334-3607 (5031223 18051485-5488 INDIANAPOLIS (6041736-7221 PENNSYTS NIA Pacilo Predate Syalema Dala Domain Campuler Banne.. STOWN Share. Ltd 18051483.1188 (317)251 -3139 PALO ALTO Business Compiler 18041438 -3282 CanpWers Caneepla The Life program in listing 1 was written Byte :hop El Unllmller Quill Computer 14121729 -3510 SY41ema 14151327 -8090 13171849 -6505 PASADENA FRATER 18041884 -5032 in BASIC E and run on an IMSAI 8080. Walla Campuler IOWA Personal Computer WINNEPEG R131684-3311 WATERLOO Carparallan Micro-Byle Ltd is SAN DIEGO The Computer 12151 847 -0480 12041833 -2010 Since it necessary to reference the present Computer Center Cerner HUNTINGDON ENGLAND -5302 -9504 VALLEY 17141292 13191232 LONDON generation's matrix while developing the CFmpulerlan dal line Syalema -8870 Campuler San Mega KANSAS 12151947 -9912 OVERLAND PARK A-- Ipaliona next generation's matrix, two arrays, A and 1721560 TENNESSEE Research SAN LUIS OBISPO Personal Cempuler KNOXVILLE 373-4934 Byte Slop of Center. Inc 1011 B, are used When an ele- (9131849 -5942 Byte Shops SALFORD alternately. array (805)543-9310 al Tennessee SAN RAFAEL MANCHESTER KENTUCKY 40365 Campuler Design ment represents an occupied square, it is Byle RAF- EL LOUISVILLE Syslema 14151 457-9311 Memory TEIASTEXAS Como., 1501m Ca FORT WORTH PARIS given a value of 10. 1 is added to it for each AllernalNes 15021428 -OÁ29 TalCyCampulera PARIS 14151459 -1388 lam 335 -7198 Computer 9ENigue occupied neighboring square (including itself SANTA ANA MARYLAND HOUSTON Elea Can47 Advanced ROCKVILLE Campulercrall Inc Elea arts Microcomputer Campuler Warkslop 17131977-0884 Shay Pana for convenience). Consequently a square in Products (3011488-0455 CanptAertea 1714)558-8613 (7131526-B934 GERMANY SANTA BARBARA MASSACHUSETTS Alpha Campuler So Whorl HOLSTEIN the next generation becomes occupied if its Byle Shop al WALTHAM 17131885 -0477 Digilranic Computer Marl Ian A LUBBOCK 7343,410368.89 103 corresponding element in the present genera- MANTA MONICA (671 Wee of e99J540 Mission CEnIrEI 18171 Wep Texas MUNICH tion array is equal to 3, 13 or 14 (an empty (213)829-5137 MICHIGAN Mom 765-7134 Dalalneg KG The Campuler Share ANN ARBOR RICHARDSON (089480.4993 1213) 451 -0713 Campuler Share al The Micro Share square with three neighbors or an occupied -1096 HOLLAND SHERMAN OAKS (3131 995.7616 (2141231 Peoples RFmci ROYAL OAK UTAH Telex 50483 square with two or three neighbors). TARSAN Co Computer Marl al TARZANA SALT CITY 13131578 -0900 Byte SAE- of HONG KONG Ted1 Merl Statements 1 through 13 establish the 355 -1041 CAUSEWAY BAY (213)344-0153 MINNESOTA in') Dala world Tellec VAN NUYS MANKATO 5793-669 Campuler Norhh Kalo Supply (8011 943-0033 number of generations to be printed and the Camparonla 15071825 -5475 VIRGINIA JAPAN (2131344-0153 MINNEAPOUS ALEXANDRIA TOKYO initial occupied squares (in the A array). Nihon Termnal WESTMINSTER Campuler Sepal The Campuler Byte Shop al 16121 927 -5801 Hardware Share. Canuler Statements 19 through 25 print the contents (71418949131 MOOREHEAD Inca, araled Tokya170 S Inc 1703) 548.BOe5 SPAIN COLORADO 121812161 233 -888 2 BOULDER SPRINGFIELD BARCELONA of the A array and zero the B array. State- ByleShapal MISSOURI The Campuler Inlolecnas WOK 13031444 -8550 PARKWILLE Wareahapaf 10001 235-7110 ments 27 through 34 generate the B array DENVER Campuler Virginia. Inc SWEDEN Byle Slop al Workshop 17031 3 21 -9 04 7 BROMMA :3031399.8995 19181452 -3B90 VIRGINIA BEACH from the A array. Statements 36 through 42 Computer Hut Home Computer Menti AB MONTANA Cerner. Inc IPnme Radial SWITZERLAND print the B array and set the A array to zero. 13011573 -4895 BILLINGS 18041340 -1977 Big Sky Byte Shop ZURICH Mini Corn.. A G 14081252-2299 Statements 44 through 52 generate the A ENOINGLEWOODE er Ca 10112422803 Mhi Mini VENEZUELA array from the B array and then loop back Computer Co CARACAS 13031 770.5005 E DC MEGA. C A 3379 -90 to produce the next two generations.

82 December 1978 ©BYTE Publications Inc Circle 4 on inquiry card. Thinking of adding mass memory to your S-100 bus?

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You say you're ready for greater storage? Thinking of even more mass memory? Well now, with average access times of 28 Check out the ALPHA MICRO AM -400T4 milliseconds, large, on -line direct access car- Hard Disk Subsystem. It features the tridge disk files have become a reality in CALCOMP TRIDENT Series Hard Disk microcomputing. And, ALPHA MICRO Drive in a choice of models with 25, 50, 80, offers you not one, but TWO ways to vastly 200, or 300 megabyte capacity. And, you increase your system capacity... and do it can daisy -chain up to four units, on -line, in without overtaxing your budget. any mix. How's that for capacity? First, there's the ALPHA MICRO AM -500T4 So, if you're thinking of adding mass Hard It Disk Subsystem. uses the popular memory to your S -100 bus, be sure to check "A CDC 9427H (Hawk) cartridge disk drive out the ALPHA MICRO AM -400 or AM -500 AM 400 AM 500"" with a total of 10 megabyte capacity (5 fixed, Hard Disk Subsystem at your nearest ALPHA 5 removable). The AM -500 comes com- MICRO Dealer. And while you're there, ask plete with interface formatter /controller, him to show you the rest of the ALPHA 1 alpha cabling, and disk drive. You can expand MICRO hardware and software lines. t,m.cro your mass memory to meet your require- , 17881 Sky Park North ments, in 10 megabyte increments, up to Irvine, California 92714 40 megabytes. (714) 957 -1404 Circle 4 on inquiry card. BYTE December 1978 83 Chess 4.7 versus David Levy

The Computer Beats a Chess Master

J R Douglas After 29 years, computer chess finally The original feeling of confidence Levy 25 Cannon Dr achieved a victory in human competition at held must have been somewhat shaken as the Elk River MN 55330 the master class tournament level. During years 1973 and 1974 saw Chess 4.0 achieve a the fourth game of a match held at the United States Chess Federation rating higher Canadian National Exhibition from Au- than that of the average US tournament gust 26 to September 4 1978, International chess player. [Note: the version number of Master David Levy resigned to Chess 4.7/ the program increases along with its skill.] CYBER 176 after 56 moves, although he did Then, in 1976 and 1977, when Chess 4.5 win the tournament, 31/4 to 11/2. and 4.6 won the class B championship at the David Levy was three years old in 1949, Paul Masson Open Chess Tournament and when the American mathematician and won outright at the Minnesota Open, Levy computer science pioneer Claude Shannon conceded that he had begun to think that his produced the first paper describing the match with Chess 4.7, "would not be a for- methodology for producing chess playing mality but could be just a bit of work." computer programs. Not until 1956 did any The latter part of 1977 and early 1978 machine win a game against a human op- saw a series of 2 game matches between ponent: MAN IAC, a system developed at the Levy and Chess 4.6, the Duchess program Los Alamos Scientific Laboratory, won a from Duke, Greenblatt's MIT program, and greatly simplified chess game against a Kaissa from the USSR. Levy handily de- novice player in 23 moves. feated all the programs in the first game. 12 years later, Levy, expert rated and Chess 4.7, running on a Control Data Scottish National Champion, attended the Corp (CDC) CYBER 176, had compiled a Fourth Annual Machine Intelligence Work- rating of 2030 after 31 tournament games shop. There he took exception to the views and a speed chess performance rating of of John McCarthy of Stanford University 2450, when the last challenge was given. The and Prof Donald Michie of Edinburgh issue was to be resolved on the tenth an- University, who agreed that within ten niversary of the original wager, with play to years a computer system would be World begin on Saturday, August 26. Champion of chess. Levy countered that not Getting a computer to a chess match, only would computers fall short of that goal, which was the duty of this author and Dr but they would be unable to defeat him in a Dave Cahlander, is a considerably more tournament style match within that 10 year difficult task than getting a human to a period. Neither side was able to shake the match. Crossing the Canadian border with other's convictions and, as a result, Levy microprocessor controlled chessboards, and wagered £1250 sterling that he could defend setting up and testing telephone lines and against the computer advances. modems between Toronto and the CYBER The machine intelligence community had 176 in Arden Hills MN consumed most of a expected Levy to be defeated by a large net- wee k. work of computers participating in the The glass box in which the match was game, until 1970, when a Northwestern held, standing beside three bowling lanes University program called Chess 3.0, written and a fencing exhibition, faced a large by Larry Atkin, Keith Gorlen and David demonstration chessboard and seats for on- Slate, clearly emerged as the leading effort lookers. A square of chess tables used in in the first US Computer Chess Champion- simultaneous play filled the rest of the ship. David Levy was then 24. room. Opposite the glass box was the stand

Photo 1: International Master David N L Levy ponders his move while sitting in the glass enclosed booth at the Canadian Na- tional Exhibition. A crucial position in one of the match games appears on the electronic chessboard, which is connected by telephone lines to a Control Data Corp CYBER 176 computer.

84 December 19780 BYTE Publications Inc

of Josef Smolij, local speed chess king and guru of the all- night, outdoor Yonge Street Chess Association. Josef, we were to learn, would play a large part in the first win ever for a chess machine at the master level.

GAME The relationship between the opponents in the Levy match is difficult to describe. W , The two Davids, Levy and Slate, and the ii_y /i CDC folks stayed in the same hotel and ate i,,,,,i ,/ a;:, i 'l' 'f meals, travelled and generally spent the en- i A tire time together as friends. Levy even con- A sidered the machine to be sort of a friendly rims j foe. Each night the entire group found itself x / / % on the sidewalks of Yonge Street playing 'G i chess on overturned milk cartons with Joe i% Smolij until the small hours of the morning. n , A i Joe demonstrated his "Smash- Crash" Gam- j /% g Ai!!;,% bit (also known as the Greco Counter Gam- ji POSITION AFTER 12. P -KR3 bit for those who have not yet met Josef) ; for 50 cents a lesson. Figure 1: Position occurring in round 1 Levy's plan for the match was not diffi- after White's 12th move. The player of cult to anticipate, since he had demonstrated Black next unleashes an attack which wins that, while tactical positions favored the material and disrupts White's Kingside. computer, strategic positions favored him. He had used close, quiet games to defeat the computers in each defense of the wager, playing a strategic game until a weakness 1. P-KN3 P-Q4 33. NxR RxN 2. B-N2 P-K4 34. B-N4 R-KB6 developed in the computer's position, then 3. P-Q3 N-KB3 35. R-Q8 P-KR3 winning against that weakness. 4. N-KB3 N-B3 36. RxP RxP game 1 is 5. O-O B-Q2 37. R-Q8 R-KB6 The score of round presented 6. P-N3 B-QB4 38. R-R8 P-KN4 in the form of a Turing experiment. For 7. B-N2 Q-K2 39. P-Q5 P-KR4 those not familiar with him, Alan Turing 8. P-QR3 P-K5 40. P-Q6 K-N2 9. N-K1 O-O 41. RxP R-B2 proposed a method for determining whether 10. P-Q4 B-Q3 42. R-R5 K-B3 a machine should be called "intelligent." In 11. P-K3 N-KN5 43. B-B3 check K-N3 this test, a human, linked via teletypewriter 12. P-R3 NxP/6 44. R-K5 R-B6 13. PxN Q-N4 45. B-N4 R-B5 with a machine, is told that he is communi- 14. P-KN4 QxP/6 check 46. R-K7 R-B2 cating with either a machine or another 15. R-B2 B-N6 47. RxP/4 R-Q2 16. Q-K2 QxR check 48. R-K7 P-R 5 human. If he is unable to determine with 17. QxQ BxQ check 49. K-N2 P-N5 which of them he is communicating, the 18. KxB P-B4 50. K-R2 P-N3 machine can be termed "intelligent." The 19. PxP N-K2 51. K-N2 R -Q1 20. P-B4 RxP check 52. P-R4 N-Q2 question: was Levy White or Black in game 1 ? 21. K-N 1 P-B3 53. P-R 5 N-B3 Consult table 1 and form an opinion. The N-QB3 R 22. -R4 54. PxP N-Q4 answer appears in the text box on page 90. 23. K-R2 R-KB1 55. P-N7 NxR 24. N-01 N-N3 56. PxN R-KR1 The first game was a draw. This created 25. R-B 1 BxP 57. B-Q6 K-B3 a great deal of speculation, as most of the 26. BxB R-B8 58. P-N8=0 RxQ 27. N-N2 R-B6 59. BxR KxP 28. PxP R/4XB check 60. B-B4 K-B3 29. K-N 1 PxP 61. B-Q2 K-N3 GAME I 30. R-B8 check N-B 1 62. B-K1 K-N4 31. B-B3 R-Q6 63. B-B2 K-R4 32. N/1-K3 R/RxN Game agreed drawn.

Table 1: The score (record of moves) of game 1 of the match. The reader is asked to examine this game, and to form an opinion concerning which player had which color of pieces.

About the Author

f R Douglas has 16 years of experience as a microprogrammer, and POSITION AFTER 63. ... K -R4 maintains an interest in artificial intelligence. His hobbies include photography and amateur radio (callsign KA OACN). Figure 2: The final position reached in game 1. The participants agreed to a draw.

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Circle 75 on inquiry card. BYTE December 1978 87 GAME 4 GAME 4 % % % ILA/ /j/Y//%ji,., ., '%%;, i //: %!%% ß %

%%%% %; y % f //O//i%, ,,,ij ! rAj rAj,jPOSITION AFTER 47. ...K -K2 %Ó,POSITION AFTER 56.i P -86 Figure 3: Position reached in game 4 after Black has made his 47th move. Figure 4: The final position of game 4. The human chess masters present, including Canadian Master Bruce Amos White's pawns will march irresistibly to the and 14 year old US National Master Joel Benjamin, were of the opinion that eighth rank and become Queens. Black can White must lose material. White did have a move they missed, and played it. find no way to stop them, and resigns.

Chess 4.7 Levy Chess 4.7 Levy

1. P -K4 P-K4 30. R-K3 B-R3 2. N -KB3 P-KB4 31. N-K2 3. PxP P-K5 4. N -K5 N-KB3 Chess 4.7 forces the exchange of minor 5. N -N4 P-Q4 pieces, and thereby defangs Levy's attack. 6. NxN check QxN 7. 0 -R5 check Q-B2 31. BxN 8. Qx0 check KxQ 32. R/1xB P-B4 9. N -B3 P-B3 33. P-B4 RxR 34. RxR R -R5 At this point, Levy announced to the spec- 35. K-N3 R-R8 tators that he was playing the "Smash- Crash" 36. B-B2 R-08 Gambit, attributed to Josef Smolij of Toronto. 37. R-R3 PxP

38. RxP check K-B 1 10. P-Q3 PxP 39. R-Q7 R-Q6 check 11. BxP 40. K-N2 B-B4 41. RxP/5 R-Q7 Possessing a one pawn advantage, the com- 42. P-N4 BxP puter has forced Black's King to remain in the 43. R-Q8 check K-B2

center of the board. 44. R-Q7 check K-B 1 45. RxP/4 R -N7 11. N-Q2 46. K-B3 Photo 2: Josef Smolij, the 12. B-KB4 N-B4 13. P-KN4 NxB check This move avoids the pin of the Bishop to guru of the Yonge Street 14. PxN B-B4 the King - see why in the next move. Chess Association, as he 15. 0-0 P-KR4 presides over his midnight 16. N-R4 B-Q5 46. B-B4 17. B-K3 B-K4 47. Rß8 check K-K2 lessons in the Smash -Crash 18. P-Q4 B-Q3 48. B -R4! check Gambit. 19. P-KR3 P-QN3 20. R/B-K1 B-Q2 The human masters present did not see this 21. N-B3 PxP move. They thought the computer was certain 22. PxP R-R5 to lose material. 23. P-B3 R /1-R1 48. K -B2 Levy has seized command of the King Rook 49. .13:1\j5 P -N3 file. The defense is not at all obvious. 50. R-Q7 check K -B1 51. PxP RxP 24. K-B1 B-N6 52. P-B5 R -R6 check 25. R-K2 B-B1 53. K-N4 R -R5 check 54. K-R 5 R -Q5 The move 25. . . R -R8 with check fails 55. R-QB7 B -K2 because of the reply B -N1. 56. P-B6

26. K-N2 B -Q3 Black has no way to prevent the steamroller 27. B-N 1 R -R6 pawns from advancing to the eighth rank. 28. R/1-K1 R -N6 check 29. K-B2 R /1 -R6 56. ... Resigns.

Table 2: The score of the fourth round game. The computer had the White pieces and the first move. After Levy lost the game, Joe Smolij complained that the Smash -Crash Gambit was for use against people, not machines.

88 December 1978 © BYTE Publications Inc Photo 3: In game 4, David Levy stolidly ponders the position after his

move 51 . ... RxP. The computer's material and positional advantage is large, but tenaciously he seeks the best defense.

Photo 4: Levy forms his plan, and reaches out over the flickering electronic chessboard to put it into effect. He may persuade the computer to trade Rooks. Getting rid of Chess 4.7's troublesome Rook would allow some freedom of movement for Levy's beleaguered King.

Photo 5: The computer decides not to trade Rooks. Levy pulls his Bishop back to act as a shield against the final assault. He smiles as he sees that the steamroller pawns will not stop.

December 1978© BYTE Publications Inc 89 assembled experts had predicted a 3 game What happens now? A new version of the conclusion to the 6 game match. The rules program, Chess 5.0, waits in the wings, the required that Levy obtain only three points CYBER 176 spends most of its waking hours to win his wager. Now play would be forced hard at work aiding in the design of its suc- to at least four rounds. Levy's concentration cessor, and Levy has offered a prize of during the opening phase of the second game $5000 to the developer of a system which is did not falter as he quietly put away the able to defeat him in match play within the machine without apparent trouble. next five years. Here we go again. Round 3 was not scheduled for six days, so the glass booth, looking much like an abandoned bus stop enclosure, sat empty The answer to the Turing experiment while various masters played simultane- question (page 86): ous exhibitions against spectators, amidst David Levy was playing White; Chess the sounds of three bowling lanes and the 4.7 was playing the Black pieces. clank of sabers from the adjacent fencing The computer found a surprising matches. combination in game 1. The diagram of Play resumed on September 2. The third figure 1 shows the position immediately round was ,another closed and quiet game following Levy's move 12, P -R3. In the which Levy won without apparent effort. opinion of the computer operators, The score then stood 1/2 to 21/2, with Levy Chess 4.7 did not have any definite plan needing only a draw to win the match. when it moved its Knight to the fifth However, he chose to confront Chess 4.7 rank. But Levy took 510 seconds to ad- directly in the fourth round by playing the vance his Rook pawn. The program, cal- Greco Counter Gambit. His decision was culating during all this time, explored made only hours before, while sitting on a enough move trees to find the hidden milk carton playing chess against Joe Smolij, benefit in the otherwise unlikely appear- the Smash -Crash Gambit expert. ing move of Knight takes King pawn. Round 4 commenced with fireworks that The key move in the combination never died out during the entire game. The came after Block played its Queen to moves of that game are given in table 2. King Knight 4. Levy later said that if a Though Levy finished the match in the human master had played the Knight fifth round with another closed game and sacrifice against him, he would have held his 10 year wager, those on the com- resigned immediately. As it was, he puter chess side of the contest did demon- played on, confident that he could strate the ability to produce master level outmaneuver the machine in the end- games. The most frequently heard comment game. His confidence was justified, after the match was that there were no losers and he managed to salvage a draw. in Toronto.

Photo 6: David Slate (left), of Northwestern University, and David Cah- lander of Control Data Corp watch the computer terminal as it displays one of Chess 4.7's moves in game 4.

90 December 1978 © BYTE Publications Inc TRS-BO PET APPLE

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Box 136-B12 Personal Software" Cambridge, MA 02138 Circle 302 on inquiry card. BYTE December 1978 91 See the BrighterWriter- at these stores. Arizona Byte Shop, Tempe, AZ Byte Shop, Tucson, AZ California Z -80 Assembler Jade Computer Products, Hawthorne, CA Byte Shop, Lawndale, CA Patrick A Crowe ComputerCenter: San Diego, CA 22 Ringsbury Close Byte Shop, SanJose, CA Purton Byte Shop, San Rafael, CA Swindon ENGLAND SN5 9DE ComputerStore, Santa Monica, CA Connecticut The Computer Store, WindsorLocks, CT Colorado A Z -80 assembler that implements all of the Zilog defined mnemonics is Computer Technology. Denver. CO available from BYTE. This assembler uses the conventions established by Hawaii Zilog in the Z -80 Assembly Language Programming Manual. It recognizes Microcomputer System. Honolulu, HI Illinois uppercase characters for labels, operators and operands. All defined pseudo - Illinois Microcomputers, Naperville, IL operations have been implemented except for macroinstructions and con- Iowa ditional assembly commands. Memory Bank, Davenport, IA The assembler can be implemented in read only memory. It assumes that a Kansas console display and a paper tape reader and punch are available. However, Computer Systems Design, Wichita, KS Louisiana since the user must supply the input and output routines for the program, Microcomputers of New Orleans, LA this is not necessary, and the required functions can point to locations in Massachusetts memory. CPU Shop, Charlestown, MA Computer Mart. Waltham, MA The Nybbles Library is an inexpensive means for BYTE readers to share Michigan Newman Computer Exchange, some interesting but specialized forms of software. These programs are Ann Arbor, MI written by readers with small computers and printer facilities, and are there- United Microsystems Corporation, fore designed for particular systems. The algorithms and programming tech- Ann Arbor, MI niques in these programs can be directly used by readers with similar equip- Hobby Electronics, Flint, Ml Computer Mart, RoyalOak, Ml ment, or can serve as an inspiration for improvisation on computers of Nebraska different characteristics. Omaha Ccmputer Store, Omaha, NE Potential authors of such programs should send us a self-addressed New Hampshire stamped envelope, with a request for a copy of our "Guidelines for Nybbles Computer Mart, Nashua. NH Authors." Payment for Nybbles items is based on sales and length of the New Jersey Computer Mart, Iselin, NJ item. Rates are set at the time of acceptance. New York Nybbles Library programs are sent in listing form, printed on 8.5 by 11 Mini -Micro Mart, Syracuse, NY inch paper on both sides. The Nybbles Library programs are 3 hole punched Ohio for collection in loose leaf binders, and come in an attractive folder which Cybershop Microcomputer Systems, serves as a cover. Columbus, OH Dayton Computer Mart, Dayton, OH This month `The Z-80 Assembler" (# 101) has been added to the Nybbles 21st Century Shop Library. To order your personal copy, at $4 postpaid, fill out the coupon Cincinnati, OH below. Oregon Real Oregon Computer Company, Eugene, OR ComputerPathways Unlimited, Salem, OR Please send copies of BYTE Nybble # at $ postpaid. lias Micro Mike's, Amarillo, TX Check Enclosed Interactive Computers, Houston, TX Bill my BAC Exp Date Byte Shop, Richardson, TX Virginia Bill my MC = Exp Date Computers Plus. Alexandria, VA The Computer Place, Roanoke, VA Namo Washington, D.C. Georgetown Computers, Street Washington, DC Computerland City State Zip Code cil most stores

BYTE Nybbles Library, 70 Main St, Peterborough NH 03458 Integral Data Systems, Inc. You may photocopy this page it you wish to keep your BYTE intact. 14 Tech Circle, Natick, MA 01760 (617) 237 -7610 92 December 1978 © BYTE Publications Inc t Pay a little bit more and get a printer that's brighter than your computer. The BrighterWriter:-

When a few dollars more buys Picture your page as thou- button to turn it on. A test button to you a first -class impact printer, sands of dots. The BrighterWriter self -test your printer. A paper feed why settle for a toy? The Brighter- can fill in the dots, plot them con- button to advance the sheets or Writer gives you quality to start tiguously, stack them, or scatter forms. Aline feed button to with. And versatility that stays them. And its special set of gra- advance the paper a line at even if you outgrow your phic characters a time. present personal computer. ; simplifies the :' __ - _= Prints Built smart like the big ones. process. any- which- way. The BrighterWriter's a smart _ Prints any char- The BrighterWriter comes in printer. There's a microcomputer :; acter a typewriter two models. The IP -225, at $949, inside. It outwits even the bigger, can. Faster .. . gives you a BrighterWriter with higher-priced printers. So you The BrighterWriter can print tractor-feed drive for precision get versatility to do all kinds of plain and simple. With 7x7 dot forms control. This one can printing. And power to grow on. matrix clarity. You get all the let- handle everything from labels to 81/2" mr,e anal Prints fat, skinny, ters, numbers, and standard paper widths. tall, small.* symbols of a It has eight form lengths and ,IMPI This printer can regular gives you all the features of our be as creative IP -125...... as your imag- J A brighter

ination. Stretch buy. _ .. out your char- Our IP -125, acters. Squeeze them close. friction -feed, BrighterWriter Make them high. Low. has a 96 character set and Bold. Banner. You name it. prints on 81/2" wide paper. Plugs into your computer Upper and lowercase. It prints Most popular personal expanded characters, too. computers interface to the You can choose a RS -232 serial BrighterWriter. Simply and typewriter. At up or parallel interface. $799 quickly. Hundreds of to 80 cps throughput. Lots of goodies. Brighter Writers are working in Ordinary paper. There's more. Choose all kinds Apple, TRS -80, Heathkit, S -100 Fancy or plain, the Brighter- of options for your BrighterWriter. and many other personal com- Writer prints on ordinary paper. Up to 132 characters per line, var- puter systems right now. Better yet, it prints on many iable character densities, larger Pictures and fancy shapes of paper. Single sheets. buffers, special graphics pack- symbols.* Roll. Fanfold. ages, interface cables, and more. The BrighterWriter Want more copies? The Give us a call or write. Integral draws out your cre- BrighterWriter prints multiple Data Systems, 14 Tech Circle, ativity. You can print copies without extra adjustments. Natick, MA 01760, (617) 237 -7610. drawings, graphs, Four easy buttons. Better yet, see the Brighter- diagrams, bold symbols, or just Operating the BrighterWriter Writer at the store nearest you. about any graphic you can couldn't be simpler. Up -front con- imagine. trols are easy to get to. A power Integral Data Systems, Inc. Some of these advantages require extra-cost options. Circle 177 on inquiry card. BYTE December 1978 93 Interface Your Computer

to a Printing Calculator

Robert H Astmann 58A Spring St Red Bank NJ 07701

Hexadecimal Hexadecimal There are many microprocessor applica- Row Column tions in which it is desirable to produce a Vector IRWVCTI Vector ICLVCTI Key hard copy of numeric information being 08 01 "0' measured or computed, yet even the cheapest 04 01 "1" today's low cost printers could easily 04 02 of a 04 04 '3' be the most expensive component of such

02 01 system. A solution to this problem is to use 02 02 "5" one of the thermal printing calculators now 02 04 e° available. By means of an interface to a 01 01 '7 microprocessor, the calculator integrated 01 02 '8 circuit can be given stimuli identical to those 01 04 "9" received during the normal pushing of the OF 08 "T' calculator keys. In this article I describe OF 04 Paper Advance such an interface which was implemented 01 08 = 08 08 "u" using an Intel 8080A processor and a Texas Instruments 5050M printing electronic calculator. Table 1: Contents of the row vector and column vector tables (RWVCT and CLVC1; respectively) referenced by the program in listing 1. Basic Control Procedure

I first describe the method by which data is normally entered on a calculator keypad. Referring to figure 1, each button OUTPUT FROM CALCULATOR CIRCUIT on the keypad provides a unique connection between a column output line ,COL I COL 2 COL 3 COL 4 COL 5 and a row input line. The calculator integrated circuit outputs a scan pulse to each V V W V column bus sequentially, and looks for an -..M. A. input pulse from one of the rows. The ww,'"ei interpretation given to a detected row signal 1 1 is therefore dependent on which column . is being accessed during the given time period. The job for the microprocessor in this 1 ROW I application is to monitor the column signals .. .. . I until the column containing the desired IC character key is active and then to drive the

I ROW 2 correct row bus to a high level so that the J I calculator circuit senses the input while the o° y a given column signal is still active. The

I ROW 3 microprocessor software controls this proce- a dure by using two stored lookup tables (see table 1): a list of column vector bytes and a list of row vector bytes. The entries in these I 1 1 ROW 4 ( two tables, together with the code for the

Figure 1: Keyboard arrangement of the Texas Instruments 5050M printing calculator. Calculator logic outputs a scan pulse to each column bus sequentially and looks for on input pulse from one of the rows. This uniquely identifies the key pressed by the user. Although there are only four row inputs to the calculator circuit, there are five rows of keys. Signals from the upper row of keys appear simultaneously on all four row inputs through the diode network.

94 December 19780 BYTE Publications Inc Circle 293 on inquiry card. FRIDAY, SATURDAY, & SUNDAY, APRIL 6, 7, & 8,1979 Beat the Northeast's most exciting show featuring You'll be entertained, educated, enthralled! Win microcomputers and small computer systems. valuable prizes in the computerized mouse maze The Northeast Business & Personal Computer contest, programming contests, and other electronic Show will be the largest presentation of hardware and competitions. Hear computerized music synthesizers. software ever gathered in Boston. And it will all take See computer -generated art, graphics, and animation. place at the spectacular Hynes Auditorium in Boston's Watch computer amusements. Play dozens of elec- Prudential Center. Hundreds of displays and exhibits tronic and video games. will showcase microcomputers and small computer Internationally recognized speakers will give systems for businesspeople hobby- M. IMM M lectures and seminars for all cate- .M .M .M M ists doctors scientists engineers !MI gories and levels of enthusiasts, M M MWI .M . . M accountants homeowners = .m M ..f including introductory classes for researchers programmers 1. novices. You may even have a imi lm em im . m NNE technicians students educators. twi m chance to demonstrate your own . ims With special exhibits for children, 1.1 am mom= equipment and applications. So M M IM featuring calculators, computers, MMMM M M plan to be in Boston this April. This MI NI and educational displays. M . NIMIr . . is one show you won't want to miss! HYNES AUDITORIUM, PRUDENTIAL CENTER, BOSTON For more information call or write Northeast Expositions, Box 678, Brookline Village, Massachusetts 02147. Phone (617) 522 -4467 -+17v desired character, determine the mapping of a column input into a row output.

4- 40µ5 COL. I Hardware Interface The signalling between the TI 5050M calculator integrated circuit and keypad is illustrated in figure 2. A 17 V pulse of

COL. 2 40 ps nominal duration is outputted to each column bus with the entire sequence being repeated every 7.3 ms. This signalling continues as long as no button is pushed. When a button is pushed, the column signals are COL. 3 extended to about 150 ps to validate the button push. This pulse width is maintained until the button is released, during which time any other button push is ignored. It COL. 4 is immediately apparent that to interface this calculator to the 8080A processor, level translation circuitry in both directions

is required. The circuitry I used in this application is shown in figure 3. An Intel COL.S 8255 Programmable Peripheral Interface integrated circuit was chosen because it Figure 2: The sequence of column scan signals outputted by the calculator was already interfaced to the 8080A as a circuit. keyboard port. The diodes tied to +5 V insure that the inputs to the 8255 do not go 5 above +5.7 V when a column signal goes to +17 V. The output lines from the 8255 are connected to open col lector drivers which translate a +5 V signal to +17 V. IB lLSV 2211 1I7V The necessary connection points within PBO J COL 1

19 the calculator case were easily accessed PBI 1M COL 2 Q since there were large metal strips connec- 20 PB2 Q COL 3 ting the printed circuit board to the keypad. 21 P03 COL 4 A dual trace oscilloscope was used to deduce IC2 (C 0255 r the identity of each connection. Once the PROGRAMMABLE ICI DATA BUS PERIPHERAL columns were identified by noting the time /8080 INTERFACE 4 1LSV 1117V PCO ROW 1 displacement of the scan pulse on each bus 15 relative to the others, the rows were identi- PCI D> ROW 2 pressing and 6 5 fied by buttons looking for PC2 D> ROW 3 responses on the connections that normally PC3 D> ROW 4 did not exhibit any signalling.

L f I t 5.61( Software Interface 7 I(FROM CALCULATOR) At the heart of the printer control software is the driver program, INTER. INTER is called when a single decimal digit or con- POWER WIRING TABLE trol character is to be entered. A 4 bit BCD NUMBER TYPE 5 GROUND representation of the digit must first be

ICI 7407 14 7 loaded into the C register of the 8080A. As shown in listing 1, this character code is IC2 0255 26 7 used to select the correct column and row vectors from the two lookup tables con- Figure 3: Circuitry for interfacing the 8255 programmable peripheral inter- tained in table 1. face to the Texas Instruments 5050M printing calculator. The diodes prevent In my microcomputer system, which is the inputs to the 8255 from going above 5.7 V when a column signal goes to based on an Altair 8800 computer, this 17 V. The output lines from the interface are connected to open collector program was executed out of programmable drivers (ICI) which translate the 5 V signals to 17 V. memory which utilizes a processor wait

96 December 1978 © BYTE Publications Inc fiuuuuiìuñìíu

At last, you can get a mammoth 32K memory control and buffering, drawing typically 2.6 amps. without paying a beastly price.The SuperRamTM 32K Ask your local computer shop to order the static memory kit is just $649 for S -100 systems SuperRamTM 32K kit for you. Or, if unavailable locally, (Z -80 version, add $70). order direct from Thinker ToysTM, 1201 10th St., The latest of George Morrow's heavyweight Berkeley, CA 94710. Or call (415) 524 -2101, weekdays memory designs for Thinker ToysTM, the SuperRamw 10 -5 Pacific Time. Add $3 for handling. (Cal. res. 32K features two independent 16K blocks, each add tax.) addressable and write -protectable. It meets the Morrow makes memory for Proposed IEEE S -100 Standard with full buffering of both data and address lines. Uncommonly efficient, the Morrow design utilizes just 7 IC's for Thinker _ Judy the elephant courtesy Marine World- Africa USA state on each memory access. This had the row outputs are zeroed. The initial values effect of reducing program execution speed for the software delay counters were deter- to the point where it was not possible to mined experimentally (ie: they were ad- determine when the desired column was justed until the calculator consistently active and thus to output the appropriate printed a character each time INTER was row signal before the termination of the called). same 40 ps column signal pulse. Instead, The entries in the column vector table INTER actually scans the column inputs are set up so that a 01 vector will recognize until the column to the immediate left of column 1, 02 will recognize column 2, etc. the desired column is sensed active. Then Since INTER looks for the column to the there is a software delay, after which the immediate left of the column contain- correct row output is activated. Next there ing the desired character, characters in

is a second software delay, after which all column 1 (ie: C, %, x, etc), cannot be printed unless INTER is modified to enable it recognize when column 5 is active, then to Op to Commentary Label Code Operand delay for about 7.1 ms (ie: until column 1 is active) before outputting a row signal. LHLD POINT ; load H L with memory data pointer MOV C,M ; load C from memory with 2 low order digits Just above INTER in the software hier- INX H Segment MOV B,M ; load B from memory with 2 high order digits archy is PR2DI, the routine which enters of INX H two decimal digits. The source listing shows Main SHLD POINT ; save memory data pointer Program: CALL OUTPR ; enter the four digits that INTER is called twice by PR2DI. MVI C,OCH CALL LINE ; terminate the line Each call to INTER is followed by a soft- CALL SKIP ; skip a line ware delay to allow the calculator chip to OUTPR: MOV A,C ; get 2 low order decimal digits STA SAVE +1 ; save store the entered digit and return to the MOV A,B ; get 2 high order decimal digits scan mode. (The digits are not printed, MVI 8,0 ; clear B reg for INTER CALL PR2DI ; enter 2 high order digits since the complete line of digits has not yet LDA SAVE +1 ; retrieve 2 low order digits JMP PR2DI ; enter 2 low order digits been terminated.) The two desired digits

PR2DI: STA SAVE ; save low order digit are passed to PR2DI in BCD form via the RRC RRC accumulator. RRC In my application, the largest number to RRC ; BCD value for digit to be entered now occupies right side of accumulator be printed is four digits long. Hence the ANI OFH ; clear left side of accumulator MOV C,A routine OUTPR enters four decimal digits CALL INTER ; enter the high order digit by calling PR2DI twice. The BCD values LXI D,OF000-4

CALL DELAY ; delay for calculator response time for the four digits are passed to OUTPR LDA SAVE ; retrieve low order digit ANI OFH via the BC register pair. MOV C,A Finally, a segment of the main applica- CALL INTER ; enter the low order digit LXI D,OF000H tion program is shown. A series of 4 -digit JMP DELAY numbers is printed as they are fetched from SKIP: MVI C,OBH ; paper advance LINE: CALL INTER memory. These numbers are already stored LXI D,0 in in JMP DELAY ; delay for thermal print head response and paper advance BCD form memory since they are the

INTER: LXI H,CLVCT ; HL points to head of column vector table result of arithmetic operations that were DAD B ; HL points to correct column vector byte followed by the 8080's decimal adjust MOV D,M ; load D reg. with column vector LXI H,RWVCT ; HL points to head of row vector table instruction. First, the BC register pair is DAD B ; H L points to correct row vector byte COL: IN PORTB ; read status of column signals loaded with the codes for the four decimal ANA D ; is desired column active? digits. The memory data pointer must then JZ COL ; No, keep looking MOV A,M ; Yes, prepare to output row signal be saved in scratchpad programmable MVI C,OFCH ; initialize first delay counter

WAITI : INR C memory since the HL register pair will be JNZ WAIT1 used by INTER. Next, OUTPR is called to OUT PORTC ; time to output row signals MVI C,OFOH ; initialize second delay counter transfer the four digits to the calculator. WAIT2: INR C JNZ WAIT2 Following this operation, the calculator is XRA A ; clear accumulator a OUT PORTC ; reset row signals waiting for either more digits or line RET termination. The 5050M can be made to DELAY: INR E JNZ DELAY terminate and print a line by means of an INR D operation keystroke or by using the #15 JNZ DELAY R ET key. (If this key is pressed afteran operation, it is interpreted as a request to print a sub- Listing 1: Assembly language program for interfacing an Intel 8080A pro- total. If pressed after a series of digits have cessor to a Texas Instruments 5050M printing calculator using an 8255 pro- been entered, the numbers are printed and grammable peripheral interface. Row vector and column vector (RW VCT and the line is terminated with a "#". These CL VCT) contents are listed in table 1. The first section in the list is the por- numbers are ignored by the calculator, but tion of the main program that calls the routines. serve as an index for the benefit of the

98 December 1978 © BYTE Publications Inc Circle 343 on inquiry card. TURTLES user.) Hence, at this point in the application program the code for the #/S key is loaded into the C register and the subroutine LINE by 1cii(il,n). lnc . is called. LINE proceeds to call INTER and then causes a delay of about 0.5 seconds which enables the calculator to activate the thermal print heads and advance the paper. Small home robots Finally, the subroutine SKIP is called in controllable order to skip a line before printing the next by your computer. number.

Conclusions Attachable to any computer via parallel interface When using a microprocessor in a control (not included.) application, it is necessary to be able to "shake hands" with the device to be con- Use your Turtle to map rooms, solve mazes, dance, trolled. This is best accomplished by struc- explore Artificial Intelligence, teach geometry or turing the software so that a low -level driver programming. routine makes the handshaking transparent to the higher level software. Computer not included (batteries not needed). In this application, the signalling protocol of the printing calculator is utilized as a Brochures available Terrapin, Inc. control me chan ism by the processor. The interface between the two devices is easy Kit $300, Assembled $500 33 Edinborough Street to implement and the result is low cost S -100 Bus Interface Kit $40, 6th Floor numeric printing capability. Whenever the Assembled $50 Boston, MA 02111 calculator is disconnected from the pro- U.S. postage $5 (617) 482 -1033 cessor interface, it will operate normally Mass. residents add 5% sales tax again.

CLIP AND STRIP

Model CAS -130

CUTS AWG 30 WIRE TO DESIRED LENGTH

STRIPS 1 "OF INSULATION

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OK MACHINE & TOOL CORPORATION 3455 Conner St., Bronx, N.Y. 10475 (212) 994.6600 TELEX 125091

Circle 291 on inquiry card. December 1978 ©BYTE Publications Inc 99 Zapper

A Computer Driven EROM Programmer

G H Gable One of the most fascinating and useful chosen the processor for the system to be 50 Cliftwood Dr products of recent technology is the read the MOS Technology 6502 which requires Halesite NY 11743 only memory (often abbreviated as ROM) a memory access time of about 500 ns when and especially useful for the experimental running with a 1 MHz clock. It was very systems designer is the erasable and electri- desirable to have the read only memory cally programmable read only memory, meet this specification for two reasons. First, variously abbreviated EROM or EPROM. because of the dynamic nature of the 6502, In designing my first microprocessor it does not wait for slow memory very based system, a read only memory was a readily. Second, and by far most important,

must to contain the operating system and I wanted my arithmetic routines in read only

the floating point arithmetic firmware. I memory to run as fast as possible since I did extensive research into read only memory would be using them very often. These con-

systems and after a week or so I was ready siderations ruled out the older 1702 type

to make a specification. I had previously memories as too slow.

The choice was obvious as soon as I read about the Intel 2708. It had all the requisite features: fast (450 ns) access time, large array (1024 8 bit words) on a single chip, and easy straightforward programming. When

I designed this programmer the going price was $100; currently the prices have dropped to about $10, making this chip even more desirable. The chip is also numbered 8708 to fit into Intel's 8000 line which includes the 8080. The 2708 and the 8708 are identical

as far as I know. They are definitely inter- changeable at a pin level. There is also a variation of the design called the 2704/8704 which is arranged as an array of 512 8 bit words. The 2704/8704 is electrically and logically identical to the 2708/8708 but contains only half as much memory. The high order address line is not defined for the 2704/8704. (Rumor has it that 2704/8704 parts are identical to 2708s but wired into the package with the high order address bit unconnected.)

System Design

Photo 1: The prototype computer read only memory board with four EROM My design called for 4 K bytes of read parts in the center. The eight sockets on the right hold the 1 K bytes of pro- only memory resident firmware which could grammable memory which is selected by a jumper on the pins in the lower be built up over a period of time as the center of the board (off pin 24 of the lowest EROM). The 8212s on the left operating system and arithmetic routines are the address bus drivers (lower pair). 8212s are abundantly used because were debugged. My approach to this was to they are the author's favorite all purpose medium scale integration chip. prototype the eventual firmware in normal

100 December 19780 BYTE Publications Inc programmable memory and then transfer through the lower eight lines (PAO -PA7) it to read only memory after debugging. I while three of the upper lines (PBO -PB2) designed a 4 K byte read only memory board control the multiplexing and programming (photo 1) which has four 2708 PROM chips current. plus 1 K bytes of programmable memory. The driving computer is expected to The programmable memory can be jumper direct the following sequence of events selected to occupy any 1 K page on the which will program one address location in board. This allows for prototyping a routine the 2708: in the actual address space that it will even- PBO is tually occupy. The system has worked out brought high to enable the extremely well. upper 8212 (IC1) eight bit latch. The lower eight bits the address It was my original intention to have the of are loaded on PAO -PA7 and read only memory programmed by profes- thus into the 8212. sionals offsite. My impression was that 2708 programming was somewhat complex and PBO is brought low latching the low address onto the outputs of IC1 which that a programmer board for a limited are wired to the address inputs the number of burns was not very practical. After of 2708. learning more about the 2708 my attitude PB1 is brought high to enable the lower changed. A little thought convinced me that 8212 (IC2). The upper two bits of the A Note About UV Bulbs: a computer driven programmer could be MSC Macalaster is located simply constructed at minimum cost. It address are loaded on PAO -PA1 and latched when PB1 goes low. at Rte 111 and Everett would be very convenient to be able to Tpk, Nashua NH 03060. The data byte is loaded on PAO -PA7 program the chips in my own computer and and latched by the PIA. to be able to make changes and corrections PB2 is brought high for the pulse time with a short turnaround time. gating the program current to the Programming the EROM EROM. When initially received, and after each This sequence is repeated the required erasure, all the bits of the 2708 are in the number of times to program the EROM. "1" state (output high). The content of the 2708 is programmed by selectively changing state to "0" in the desired bit locations. Programming a given byte requires the address of the byte on the address input pins and the data byte on the data pins, all at TTL levels ( +5 V) with the write enable pin held at +12 V, a program pulse of +26 V at 20 mA is applied to the program pin. The 2708 specifications require that the program pulse be between 100 ps and 1000 ps wide. A series of pulses are required to program a particular address. Intel recommends that one pulse be administered to each address location in a loop. The number of times the loop must be repeated is a function of the pulse width. The final accumulated program current time to each address must be greater than 100 ms. Such a scheme is a natural for computer control. The Zapper programming board shown in photo 2 and figure 1 is designed to have the address and data multiplexed to it through a peripheral interface adapter (PIA) with at least eleven output lines. I use the peripheral interface adapter that is available on my MOS Technology KIM -1 single board Photo 2: The Zapper board with the EROM in the upper left corner. Data computer to drive the Zapper. If you do not from the PIA as well as logic power and ground come in via the ribbon have one of these PIAs I recommend either cable at the bottom which is connected directly to the computer. Program the MOS Technology 6520 or the Motorola power comes in on the cable in the upper right corner from an external 6820. The address and data are passed power supply.

December 1978 © BYTE Publications Inc 101 +5V C

114 24 12 9 10 13 14 15 16 17

CLR MD 3 VCC 4 01 02 03 04 05 06 07 08 PAO E> DII D01 AO 5 6 7 PA E> 0I2 D02 Al 7 8 6 PA2 013 D03 A2 9 10 5 PA3 E> 0I4 D04 A3 16 15 4 PA4 DI5 ICI D05 A4 E> 8212 18 17 3 PA5 DI6 D06 AS 20 19 2 PA6 LE> 0I7 D07 A6

22 21 I PA7 0I8 DO8 A7 13 PBO DS2 STB GND DSI +12V 12 Î 19 IC3 VDD 2708

20 CS/WE +5V

24 VCC +5V 21 F- VBB 14 24 -5V CLR VCC MD 4 23 DII D01 A8 6 22 012 D02 A9 VSS PROGRAM 013 12 18 014 IC2 01.5 8212 016 0I7

018

PBI E> DS2 +26V STB GND DSI

I 12 I

+5V 2.7K 40407 2.7K

40407

4.7K PB2 Ejr 2N2124 27K M2.5

Figure 1: The address and data information for the Zapper is multiplexed through the PIA ports PAO-PA 7 while control signals are presented on PBO -PB2. PBO is connected to the enable pin of the upper 8212 which latches the lower eight bits of the address. The high two bits of the address are loaded and latched on the lower 8212 by PB1. The data byte is latched by the PIA. When PB2 goes high, program power is gated to the program pin of the 2708 by the 3 transistor high current gate in the lower right.

102 December 19780 BYTE Publications Inc FROM SYNCHRO-SOUND Printers THE COMPUTER PEOPLE AT PRICES YOU CAN'T 4QtLar gS S 4glrinters AFFORD TO IGNORE! rOKIDATA SL 125 CENTRONICS LINE PRINTER 703 SERIAL PRINTER

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Circle 355 on inquiry card. BYTE December 1978 103 Software

The driving software, as shown in listings

1 to 4, implements the above sequence of events in a double loop. The inside loop, PRO MIRK L APPLA listing 2, works its way through all the addresses to be programmed and gives each location a 600 Ps programming pulse. The 0200 AD P LOA 5F! INITIALIZE CYCLE outer loop, listing 1, repeats the process 0202 05 STA CYR COUNT TO 255 0204 OD 01 17 STA PROD SET PIA oillEcilaN 255 times giving a total program current LOA 5.TF REGISTERS FOR time 153 ms each This is sufficient 03 17 STA PODO OUTPUT PORTS of to bit. rarss time to program the 2708. The start and end plus EtE OE wv[o one addresses of the programmable ewe memory block are loaded in BSL, BSH and tE LOA BSL TRANSFER STARTING 0210 05 BEL. BEH registers respectively before OE rtmsrzx Lac'"'" execution is begun. Data is programmed into

021E 20 02 NXAD YS: 2PN BURY PULSE the same relative addresses in the read only memory as they are found in the program. EEEO OE BNE Al LOCATION REGISTER 0225 E6 11 14C LRN made memory; ie the low ten bits of the LRL address re the same. OE CKP BEL COMPARE LOCATION ESO Notice that the 2708 can be partially Ettt programmed. If the memory be ter atx rar ceo ar acate block to copied is less than 1024 bytes long, only 0233 C5 tt tgp DECREMENT CYCLE BIC MECY COUNT the appropriate bytes are programmed. The El LOA remaining locations are unchanged The UNEN DONE AID JSM m be can start and end tE .r It aw OMTOO RETURN 0 MONITOR Mock to programmed anywhere in the 1 K page. This is a very useful feature as it allows firmware to be Listing I: The japper Program progrommrrwble memory starting address developed over a period of time. The partially (851,85H) alai ending address plus ont (BEL,BEH) are set before erects. programmed read only memory can be used thon. The driving program sets up the PIA ports as outputs and insures that in the meantime. Incidentally, listings 2 and the control lines (PROW are off (taos) before programming power is oaplied. 3 are subroutines only for the sake of The loop through the addresses M the location register (LRL,LRH) supplies modularity and the whim of the author. a turn pulse for each location. The cycle is repeated so that each location They are called at only one point each. receives 255 pulses. The end of the program P signaled by the Teletype bell It is very important that the .26 V pro. or terminal signal. gramming power be off at the power supply until the computer has had a chance to latch PB2 low. After this initialization, a pause is built in to allow the operator to turn on the PRO GRAM ZAPPER/ BURN power supply before continuing. This pause v AWLS, is implemented by waiting for input from a 17 in MSG, listing 3. The 0244 GET LOY .aooess tra terminal subroutine 17 PUT IN were application of program power before the OPEN HICM .000/11 02411 17 computer has initialized the Zapper board 1ooa11 w will usually result in some random location 00 17 LATCH Amon, being burned with some random data. gg 17 STA POD 1.0 IT LATCH Erasing the FROM loom orn m unit TURN om. Paootu The 2708 is very easily erased using an 17 1311 ultraviolet light source. Intel specifications RO sun soous indicate that an integrated dose of 10 watt. DEY sat /anT at a wavelength of 2537 angstroms Tuno ore Pemoo is required to erase the 2708. A quick glance 17 eO PWLO at the CRC Handbook Chemistry and ris anw of Physics shows that 2537 angstroms is the most persistent spectral line of mercury Listing 2: The burn subroutine multiplexes the address and data tMangh the (Hg). This means that any mercury vapor

PIA port (PAD) controlled by the control lines (PhD). A 600 o program- lamp will do the trick. I use a nice packaged ming pulse is applied after the address and data have been latched. The INC source from MSC Macalaster (Catalog #3400) WR instruction does nothing more than provide a 5 ou delay. It is used first which sips over the top of the read only to let the data lines to the FROM settle before the programming pulse Is memory. (When using the unit, discard the applied. Later it is used in the pulse timing loop simply to cut down the filters which come with it, and be sure you number of iterations. shield your eyes from the lamp.) The chip

IDO o,.,....wnoevrz What do the S -100, the Heath H8, the Radio Shack TRS -80, the Apple, the Digital Group, and the Intel /National 80/10 and 80/20 machines have in common? Support from ÇompuKwM

Extended warranty. We believe in our products, and we back them up with a 1 Whether its flexibility, economy, or reliability that you're looking for, year (not 90 day) limited warranty that covers any defects in materials or you only need to look to one product line: CompuKit from Godbout workmanship. Electronics. We're the ones who deliver when we say we will, play Choice of "unkit", assembled and tested, or CSC qualified boards. Most of close attention to the needs of users, and enjoy a doubly enviable our memory boards are now available as 'unkits ", with sockets and bypass caps reputation for reliability with cost -effectiveness. pre -soldered in place for easy assembly. In addition to standard assembled /tested boards, we also qualify boards under the Certified Systems Components program. These boards are burned in for 200 hours, serial numbered, and guaranteed to run Here are some more reasons for our popularity ... at 4 MHz over the full temperature range. We exchange CSC boards if any defect occurs within 1 year of invoice date. All our Econoram" memory kits offer the following Extensive bypassing of supply lines Tri -state outputs for use with bidirectional busses Static design for problem -free interfacing with a variety of systems, and Guaranteed under 450 ns access time (conservatively rated; many users elimination of dynamic timing requirements are running our boards in 4 MHz Z -80 systems) Low power operation with guaranteed current specifications Dip switch address selection and deselection All lines buffered for reliable data transfer High quality, solder masked and legended boards with sockets for all ICs Write strobe selection switch for S -100 boards (allows use of memory S -100 memories are compatible with all S -100 machines with or without front panel)

`" S -100 Products Other Computer Products 8K ECONORAM TRS -80 CONVERSION KIT $139 ( unkit), $159 (assem) Our least costly way to add memory to S -100 machines. Configured 5159 as two independent 4K blocks. with separate protect for each block and Expand the TRS.80 mainframe from 4K to 16K, or use vector interrupt provision if you try to write in protected memory. with the memory expansion module; our detailed Handles DMA. Less than 1500 mA current consumption. instructions describe both conversion processes. Includes all parts necessary for conversion. and is backed up by our

standard 1 year limited warranty. Also suitable for 16K ECONORAM IVTM $279 (unkit), expanding memory in APPLE computers. $314 (assm), $414 (CSC) 12K ECONORAM VIT" Manual write protection for 4K blocks, use with or without phantom line, runs DMA at 2 or 4 MHz. Guaranteed under 2000 mA current $235 (unkit), $270 (assembled) (typically 1500 mA). Finally ... static storage at less than the cost of dynamic equivalents! Same basic features as our S -100 memories, but designed specifically for the Heath H8. Configured as two blocks with switch selected protect. Also includes hardware and edge connector required to mate mechanically with the 24K ECONORAM VIITM $445 (unkit), H8. $485 (assm), $605 (CSC) Our top of the line. Configured as 4 independent blocks (two BK and r 32K STATIC two 4K) for unique addressing options. Write protect for each block; use with or without phantom line; provision for two qualifiers; runs DMA at 2 or 4 MHz; draws less than 2500 mA (1800 mA typical). S-100 MEMORY: 11 SLOT S -100 MOTHERBOARD $ 599! Inlcudes all edge connectors pre -soldered in place, with extensive Full feature "unkit" offers $90 (unkit) supply line bypassing and active termination for reliable data transfer. Dimensions: 8.5" by 11". low power comsumption, guaranteed 4 MHz operation . 18 SLOT S -100 MOTHERBOARD and of course, the reliability $124 (unkit) Same features as above. but 18 slots. Dimensions: 8.5" by 16.7 ". of an Econoram.

FREE FLYER: We stock much more than we could possibly fit in any onead. Did you know. for example. that we stock some of the best mother- TERMS: Allow 5% shipping, excess refunded. Cal res add tax. boards around? That we carry a full line of components? And that we VISA° /Masterchargem call (415) 562 -0636, 24 hours. COD distribute a wide range of Vector products? Send us your address. and the OK with street address for UPS. (85' COD charge applies). flyer is yours. Or. send 41' for I st class delivery - avoid the bulk rate Dß0 delay. BOXBILL GODBOUT ELECTRONICS e 2355. OAKLAND AIRPORT. CA 94614 Circle 150 on inquiry card. BYTE December 1978 105 Listing 3: The MSG routine effectively PROGRAM ZAPPER /MSG causes a pause so that programming power OUTPUT THE MESSSAGE 0271 A2 00 MSG LDX S00 may be turned on after the Zapper board has 0273 BD BI 02 M1 LDA SMG.X FROM DATA BLOCK 0276 C9 00 CMP S00 (SMG) UNTIL "NUL" been initialized. Execution is resumed when 0278 FO 07 BEO RET CHARACTER FOUND any key on the Teletype is pressed. 027A 20 AO IE JSR OUTCH 027D E8 INX 027E 4C 73 02 JMP M1 WAIT FOR KEYSTROKE 0281 20 5A 1 E RET JSR GETCH 0284 60 ATS BEFORE RETURNING should be stuck in a piece of conducting foam while erasing. An exposure time of 0285 OD OA OA SMG DATA CR /LF /LF 0288 54 55 52 "TURN ON 26V-- 30 to 40 minutes will yield a fresh chip 028B 4E 20 4F PUSH ANY KEY" be 028E 4E 20 32 CR /LF /LF /NUL ready to programmed again. If you want 0292 36 56 20 to make your own eraser, use the GE #G4S11 0295 2D 2D 20 0298 50 55 53 4 W mercury vapor lamp with a GE #89C504 029B 48 20 41 ballast. Both of these items are usually avail- 029E 4E 59 20 02A2 4B 45 59 able at commercial electrical supply houses. 02A5 OD OA OA The exposure time is about 40 minutes with 02A8 00 02A9 the 2708 placed 1 cm from the bulb. My experience shows that each successive time a 2708 is erased the exposure time to HEXADECIMAL SYMBOL COMMENTS completely erase it increases. As the total LOCATION energy needed to erase it is cumulative, 0000 BSL STARTING ADDRESS OF extra short exposures can be given as needed.

0001 BSH PROGRAMMABLE MEMORY. A little program to check each byte for all ones will assure that the memory is fully 0002 BEL ENDING ADDRESS PLUS ONE OF erased. 0003 BEH PROGRAMMABLE MEMORY. It is also convenient to remember that

0004 WR WAIT REGISTER. any 1 bit in the EROM can be changed to O. Sometimes a single byte needs to be modi- 0005 CYR CYCLE COUNT REGISTER. fied and this can occasionally be done with- 0010 LRL out erasing the EROM and reprogramming it. LOCATION REGISTER. 0011 LRH This has been the case for me more often then statistics would dictate. Someone else 1 700 PAD PA PORT DATA REGISTER. must not be nearly so lucky. 1 701 PADD PA PORT DIRECTION REGISTER.

1 702 PBD PB PORT DATA REGISTER.

1703 PBDD PB PORT DIRECTION REGISTER. REFERENCES 1. Data Catalog, Intel Corp, 1975. IEAO OUTCH TTY OUTPUT ROUTINE. Intel 2. Memory Design Handbook, Intel Corp, 1975. IF5A GETCH TTY INPUT ROUTINE. 3. 8080 Microcomputer Systems User's Manual, Intel Corp, September 1975. Listing 4: External symbol table. The PIA registers (PAD, PA DD, PBD, PBDD) Intel Corporation are those assigned on the -1 board. OUTCH and GETCH respectively KIM Literature Dept output and input one character each to or from a terminal. They are part of 3065 Bowers Av the KIM -1 operating system. Santa Clara CA 95051

THE KEYBOARD: fully professional. Full 128 ASCII upper PS-80 PROM cartridge in a side slot. & lower cose characters with 79 keys including I/0: serial RS232 300/1200 baud port, full o 16 key numeric pod. parallel port. dual cassette recorder port CPU: Z -80 Processor at 300/1200 baud. GRAPHICS: 64 pre- defined graphic EXPANSION: up to 32k RAM on board I/O chars. and 64 user defined chars. to S -100 extension box for

alternately oll 128 graphic chars . additional memory and any may be user defined. Resolution other S -100 peripheral boards. 240 x 512 points, cursor control. PRICE: $895 (does not include and 64 chars. by 30 lines. CRT or cossette.) MEMORY: 4K byre power -on monitor, 8k 8K RAM $895.00 available soon byte user RAM. and 8k byre PROM external 16K RAM $1150.00 available now. cartridge with Microsoft BASIC standard. Cartridges allow 32K RAM $1395.00 available now. you to change operating systems G languages without any modification ro the standard hardware by simply inserting o EDUCATIONAL AND CLUB DISCOUNTS AVAILABLE PERSONAL CONSULTANT AND DEALER INQUIRIES INVITED See us of booth 233 of the West Coast Computer Faire.

For complete information write to: PERSONAL SYSTEMS CONSULTING P.O. Box 20286 El Cojan, California 92021 (714) 443-5353 Photography by James G Lindo Neufeld Ad Design Joanne De Vore Kwds Kopy Printing M 215

106 December 1978 ©BYTE Publications Inc Circle 303 on inquiry card. llmm* We Start With A Price That's Hard To Beat. But We Don't Stop There. Power Consumption Central Data Corporation has combined the benefits +16 150ma of new technology and high -volume company sales + 8 300ma to bring you a RAM board with more features and 16 20ma product options for less money. Other Products From Central Data Lower Prices More Memory Capability To begin with, we've reduced the price of our 16K RAM board by $40 to $249. At $425 -a price reduction of $50 -our 32K board costs less, too. Plus, we now offer a full 48K memory board for $599. These boards are expandable to 64K at a price of $185 per 16K package. Or you can start right out with a full 64K board for $775. Improved Board Design We've also added improvements to the board design at no extra cost to you. Deselectable in 2K increments. Our deselect Central Data also offers, fully -assembled and in kits, feature enables you to switch off any 2K to avoid a range of other computer products including overlap with your existing memory. (pictured above) our 2650 microprocessor, software Fully socketed memory. This feature enables packages, TV /Monitor, ASCII keyboard, and (not you to expand the memory board yourself. pictured) floppy disk system, to name just a few. Plug selectable addressing. Now you can For More Information re- address without soldering To Place an Order Other Standard Features We welcome any questions you have about our RAM Power- saving dynamic board with on -board boards or other products. To place an order, or for invisible refresh more information contact: One -year guarantee on parts and labor S -100 and Z -80 compatible Central Data Specifications Corporation Storage Capacity 16K, 32K, 48K, or 64K Addressing P.O. Box 2484, Station A 16K boundaries IL Max. Input Load Champaign, 61820 One LS TTL load Ph. (217) 359 -8010 Output Buffering On all data lines Access Time 450ns Place orders prepaid or COD. Delivery is stock to 30 Cycle Time 480ns days with shipping and handling prepaid in Con- Wait States Generated None tinental United States. Please include phone as well

Maximum DMA Rate 1 Mhz as name and address.

Circle 45 on inquiry card. BYTE December 1978 107 An Easy Programming System

Joseph Weisbecker approach can be thought of as vertical 1220 Wayne Av microprogramming with the microprocessor Cherry Hill NJ 08002 machine language used as the microcode representation. This article describes a hexadecimal inter- To illustrate the compactness of these pretive programming system which requires types of programs, I wrote a video tic -tac- less hardware than high level languages such toe program using the CHIP -8 language as BASIC, and which I feel is much easier to described below. Only 500 program bytes use than machine language. In my expe- were required versus 3000 bytes for an rience, hexadecimal interpretive program- equivalent version written in BASIC. Besides ming is ideally suited to real time control, saving memory, this also meant 2000 fewer video graphics, games or music synthesis. keystrokes for initial program entry. In It can be used with inexpensive computer addition, the CHIP -8 interpreter was about systems consisting of a hexadecimal key- eight times smaller than the BASIC inter- board and only 1 K or 2 K of programmable preter. The CHIP -8 program ran on a 1.5 K memory. Expensive terminals and large memory system with a hexadecimal key- memories required. You can aren't quickly board, while the BASIC program required and easily write useful programs that re- an 8 K system with an ASCII keyboard and quire five to ten times less memory than alphanumeric display. The CHIP -8 program conventional high level languages without took about 12 hours to design, hand code, resorting to the tedious complexities of enter and debug. I suspect that the BASIC actual machine language. version took at least as long on a much more expensive system. Interpretive Programming This hexadecimal interpretive program- This programming approach isn't new, ming approach is important for two reasons. but surprisingly few people seem to be First, it reduces the cost of the hardware using it. The technique consists of designing you need to get started in home computing. a high level pseudomachine language that is Second, it drastically reduces the amount of more powerful for specific applications than read only memory required in microproces- conventional machine language. An interpre- sor based products such as controllers and tive program is then written to execute this video games. Read only memory cost is a new set of pseudoinstructions. Each pseudo - significant factor in these types of products. instruction is really just a code that specifies A detailed example will be used to il- a machine language subroutine. This set of lustrate the hexadecimal intepretive pro- subroutines can be designed to perform any gramming approach. The new RCA functions you might need for your applica- COSMAC VIP computer will be used for tion. By staying with a machine language this example (see August 1977 BYTE, format, and not using labels or English page 30, for a description of this computer). words for instruction codes, memory re- It is a low cost, single card computer con- quirements are lower. By limiting the address- taining 2048 bytes of programmable memo- ing range and number of variables, you can ry, a graphic video display, and a hexadeci-

limit each pseudoinstruction code length mal keyboard. I had this type of program-

to several bytes for further memory space ming in mind when I incorporated features savings. Interpretive programs for these such as multiple program counters in powerful pseudomachine languages can the COSMAC (1802) microprocessor require as few as 512 bytes of memory. It architecture. has seldom taken me more than a week to The pseudomachine language used in my implement a new hexadecimal interpretive example will be one called CHIP -8, designed

language, and I can then use it for years. The for use with the COSMAC VIP system. I will

108 December 1978© BYTE Publications Inc INTRODUCING DUAL DRIVE MINIFLOPPY FOR PET!

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NEW ENGLAND ELECTRONICS CO., INC. (413) 739 -9626 248 BRIDGE ST., SPRINGFIELD, MASS. 01103 ACCEPTED, ADD 3% N EEC MON -FR! 9:30 5:30, SAT 10 2, ES. T. EOM SERVICE CHARGE.

BYTE December 1978 109 Circle 281 on inquiry card. discuss using this language rather than de- FX15 instruction. For example, if V2 scribing the interpreter for it. Suffice it to contained hexadecimal OA, an F215 instruc- say that the interpreter only requires 512 tion would set the timer to OA. This timer bytes and resides at memory locations 0000 is automatically decremented by one to 01 FF (hexadecimal). Programs written 60 times per second until it reaches 00. If in the CHIP -8 language must start at memo- the timer was set to 3C (decimal 60) it ry location 0200 (hexadecimal). The sample would reach 00 exactly 1 second later. This program described will run on a 1024 byte timer can be used to provide delays in memory system. This includes the CHIP -8 game or control programs. A tone clock is interpreter, the program, work area and also provided which can be set to cause a video display refresh buffer. The program tone lasting from 1/60 to about 4 seconds. itself only requires 60 CHIP -8 instructions. An important feature of this type of language is that all variables (registers) are con- CHIP -8 Language tained in memory. This means that debugging is generally Imited to examining Table 1 describes the 31 CHIP -8 instruc- memory locations, not internal micro- tions provided in this pseudomachine lan- processor hardware registers. Astute readers guage. Each instruction requires only two will be wondering why I maintained a fixed bytes (four hexadecimal digits). Memory 2 byte instruction length when variable addressing is limited to 4096 bytes so that instruction length was possible. Since only three hexadecimal digits are needed to absolute memory addresses are used, fixed specify a memory address. The number of variables has been limited to 16, labeled 2 byte instructions avoid addressing con- fusion that increases programming errors. VO to VF in this article. These are 1 byte variables or registers that can be modified Also, any instruction can easily be replaced or examined by CHIP -8 instructions. There by a branch instruction of the same length is also a 2 byte memory address register for debugging breakpoints or program called I, which is used by certain instruc- patching. tions. A real time clock or timer is provided. This timer can be set to any hexa- Graphic Display Approach decimal value between 00 and FF by the Before proceeding with a detailed programming example, readers will need to understand the video display system. Fig- (Hexadecimal) ure 1 shows the graphic display format used. Instruction Operation

1 MMM Go to OMMM BMMM Go to OMMM + VO 2MMM Do subroutine at OMMM (must end with 00EE) 00EE Return from subroutine 3XKK Skip next instruction if VX = KK 4XKK Skip next instruction if VX # KK 5XY0 Skip next instruction if VX = VY 9XY0 Skip next instruction if VX # VY

EX9E Skip next instruction if VX = hexadecimal key ( LSD) EXA1 Skip next instruction if VX # hexadecimal key (LSD) 6XKK Let VX = KK CXKK Let VX = Random Byte (KK = Mask) 7XKK Let VX = VX + KK 8XY0 Let VX = VY 8XY1 Let VX = VX /VY (VF changed) 8XY2 Let VX = VX & VY (VF changed) 8XY4 Let VX = VX + VY (VF = 00 if VX + VY G FF, VF = 01 if VX + VY > FF) 8XY5 Let VX = VX - VY (VF =00if VX < VY, VF =01 if VX VY) F X07 Let VX = current timer value FXOA Let VX = hexadecimal key digit (waits for any key pressed) FX15 Set timer = VX (01 = 1/60 second) FX18 Set tone duration = VX (01 = 1/60 second)

AMMM Let I = OMMM

FX1E Let I =I+VX FX29 Let I = 5 byte display pattern for LSD of VX FX33 Let MI = 3 decimal digit equivalent of VX (I unchanged)

F X55 Let Ml = VO:VX11= I +X+1) FX65 Let VO:VX =MI (I= I+X+1) OOEO Erase display (all Os) DXYN Show n byte MI pattern at VX -VY coordinates.

I unchanged. MI pattern is combined with existing display via EXCLUSIVE -OR function. VF = 01 if a 1 in MI pattern matches 1 in existing display. OMMM Do machine language subroutine at OMMM (subroutine must end with D4 byte)

Table 1: CHIP-8 instruction set. Note that invalid hexadecimal characters in the hexadecimal instructions listed are replaced by valid hexadecimal codes when a program is written. Thus 81000 might be a valid use of the BMMM instruction.

110 December 1978 © BYTE Publications Inc Everything you ewer wanted in a video (Automatic scrolling, cursor, erase functions, etc.) And less. (Stand -alone -requires no processor.

VIB -1000. Shown actual size. NPC's NEW VIB SERIES. FROM $129" Don't let the low price fool you. These are not kits. They are fully assembled and tested boards. NPC's custom CRT Processor Chip is the secret behind the entire family. All perform character entry and cursor control functions automatically. They execute all normal cursor commands as well as more sophisticated functions such as erase page, erase to end of line, etc. Text automatically scrolls when cursor reaches bottom of page. Display format is fixed at 16 lines of 64 characters for optimum efficiency. VIB -1000 All standard features described above. $129.95 VIB -2000 All features of the VIB -1000 plus FOREGROUND AND BACKGROUND video modes, SCREEN PROTECT and READY /BUSY handshake. $159.95 VIB -3000 All features of the VIB -2000 plus SCREEN READ capability. $169.95 VIB-2000S Serial interface (RS -232C) version of the VIB -2000. $189.95

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If your local computer store STEP SYSTEMS, INC. NATIONAL ELECTRO SALES does not have NPC's new VIB 4815 West 77th Avenue 12063 W Jefferson Blvd. series yet, contact the distributor Minneapolis, MN 55435 Culver City, CA 90230 nearest you to order direct. (612) 831 -3644 (213) 391 -6294

DEALER INQUIRIES INVITED

Circle 287 on inquiry card. BYTE December 1978 1 1 1 The last hexadecimal the display Figure 1: A drawing of the digit of video display. The inner instruction (DXYN) must always specify the bytes in the be shown dashed square is the play- number of pattern to on the screen. The DXYN instruction coming area. The range of X and Y is shown. pares each bit of the new pattern to be displayed with whatever is already displayed on the screen at the same spot positions. If

a 1 bit is already displayed at the same posi-

tion as a 1 bit in the new pattern to be displayed, a 0 will be shown on the screen at this spot position, and VF will be set to 01. In other words, the new pattern to be shown is combined with the pattern already showing on the screen via an EXCLUSIVE The dotted line indicates the area of the OR function. This means that after a pat- screen used for display. This display area tern is shown on the screen it can be erased consists of an array of spot positions 64 by showing the same pattern again with the wide by 32 high. These spot positions repre- same X and Y coordinates. Incrementing sent bits in a 256 byte page of memory. the X or Y coordinate and showing the When a memory bit is one, the spot position is pattern a third time would cause the illu- on (whig The CHIP -8 language specifies sion motion. the value VF is 01 spot positions on the screen by an XY of If of after showing the pattern on the screen, it coordinate system as shown in figure 1. The means that the pattern touched or hit a values of the X coordinate (horizontal spot previously displayed pattern. position) can run from 00 to 3F (0 to 63 The DXYN display- decimal). The values of the Y coordinate instruction permits ing, erasing and moving individual patterns (vertical spot position) run from 00 to 1F on the video screen. The ability to detect (0 to 31 decimal). Any two variables (VO when one pattern meets another permits to VF) can be used to specify the X and Y you to program chase, paddle and target coordinates of a spot position on the screen. games. The display instruction (DXYN) lets you show a pattern of spots on the screen. This Decimal Digits and Random Bytes pattern of spots can form a picture, letter, number, etc. Patterns are represented in Several instructions are provided to memory by a list of one to 15 bytes. Sup- permit displaying decimal numbers on the pose you want to display a rocket ship. video screen. These are useful for game You must first construct a rocket ship pat- scorekeeping, etc. An FX33 instruction tern on grid paper as illustrated in figure 2. converts the value of any variable (VX) to

The hexadecimal codes for this pattern can decimal form. Suppose 1 =0442 and V9 =A7 then be derived directly from the bit pattern. (hexadecimal). An F933 would cause 01 to To show this rocket ship on the screen be stored in memory location 0422 (hexa- with a DXYN instruction, you must first set decimal), 06 in 0423, and 07 in location

I to the address of the rocket ship pattern 0424. byte list in memory. You must then set two variables to the X and Y coordinates at which you want the rocket ship pattern to appear on the screen. The X and Y coordi- BYTE NO. BIT POSITION HEX nates specify the position of bit 7 of the first r m 7 6 5 4 3 2 I 0 pattern byte on the screen. For example, the following short program would show the .. 2 0 rocket pattern of figure 2 at the top left ..... 2 7 0 corner of the screen: 3 MME= 7 0 4 MOM F 8 Memory 5 D 8 Address Instruction . (Hexadecimal) Code Comments 6 8 8 Set = X = ... 00 ... 0200 6200 V2 rocket coordinate 0202 6300 Set V3 = rocket Y coordinate = 00 Figure 2: The definition of the rocket 0204 A20A Set I = rocket pattern address = 020A 0206 D236 Display 6 byte rocket pattern pattern is shown. The dark squares are 0208 1208 End loop encoded as a 1 bit in the appropriate byte. 020A 2070 020C 70F8 )} Rocket pattern byte list The actual value of each byte of the pattern 020 E D888 is shown under the HEX column.

112 December 1978© BYTE Publications Inc ARTEC CRAFTSMANSHIP HAS CREATED The First Truly Silent Motherboard

Noise in your bus lines means errors in your programs. The Artec shielded Motherboard totally eliminates noise. At 4MHz, the Artec shielded Motherboard is free from spurious noise. No ringing in your bus lines. No errors in your programs. This Motherboard offers you engineering and craftsmanship never before available in the small computer field. Outstanding as either a replacement for your present Motherboard or as the heart of a new system. Con- sider these features:

1 /eth inch thick -more than twice as thick as most Motherboards. Totally shielded -all holes plated through; full bus terminations. Fits easily into any standard chassis. Masterite edge connectors -the finest quality con-

nectors available. C) Trademark of Digital Equipment Corporation Ref lowed solder circuitry. No soldering required. Designed for the S -100 bus. Order today! The Motherboard price is: $150(K,T) Put an Artec board to work for you. Use your $190 (ASSEMBLED) Mastercharge or Visa. Or just send along a money order. We can accept only U.S. currency. Five years of experience in every card Please include $3 handling on all orders. Califor- For five years, Artec has worked hard to de- nia residents add 6% sales tax. velop a complete line of custom, prototype and off -the -shelf printed circuit boards. And in five years of tough industrial use, Artec boards have Please send me: (include quantity) proven themselves among the most reliable Shielded Full WW11 _ Half WW11 Motherboard Card Card boards available anywhere. I've enclosed a money order for $ Mastercharge Visa NEW! DEC' and Heath Compatible LSI (number) (exp. date) Boards Name The new Artec WW11 lets you adapt or add Address onto your DEC LSI -11 or Heathkit LSI mini- City State Zip computer. Can accom- Calif. Res. add 6% sales tax. Encl. $3 handling. 10% discount for students and computer club members. (Please enclose name of club or school) modate 14 and 16 pin DIPs plus all necessary passive components. FULL CARD $75 ARTCC CLCCTRONICS, INC. (10.45" x 8.4 ") HALF CARD $35 Artec Electronics, Inc. 605 Old County Rd.San Carlos, CA 94070 (5.225" x 8.4 ") (415) 592 -2740

Circle 10 on inquiry card. BYTE December 1978 113 tion would leave I addressing a 5 byte pattern for displaying the least significant decimal digit (7 in this example). A DXY5 instruction can then be used to display the decimal digit on the video screen at any desired position. The above example illustrates the use of an FX65 instruction to transfer three memory bytes to three variables (VO to V2). The FX55 instruction will store any number of variables in memory locations starting at

the I address. These two instructions can be used to increase the number of variables by swapping sets of variables and memory bytes. Just remember that variables are always copied to or from memory in groups starting with VO and ending with VX, inclusive. Photo 1: The actual video display of the game showing the rocket, UFO and It is often useful to generate random byte score. values. The CXKK instruction sets any variable (VX) to a random byte value. This Since A7 in hexadecimal equals 167 in random byte will have any bits matching 0 decimal, we see that the three bytes ad- bit positions in KK (a 2 digit hexadecimal

dressed by I represent the decimal equivalent number) set to O. For example, a C407

of the value of V9. If 1 =0422, an F265 instruction would set V4 equal to a random instruction could then be used to set VO, V1 byte value between hexadecimal values 00 and V2 to the values of the three bytes and 07.

addressed by I above (01, 06 and 07). An The remainder of the CHIP -8 instructions

FX29 instruction can then be used to set I should be self -explanatory. The 2MMM to a 5 byte pattern representing any one of instruction will transfer control to a sub- the three decimal digits. An F229 instruc- routine which must be terminated by

Figure 3: The range of rocket X values is from hexadecimal OF to 2E. Rocket Y is decremented from hexadecimal 1A to 00. The UFO Y remains a constant hexadecimal 08, while the UFO Xis incremented from hexadecimal 00 to 39.

114 December 1978 © BYTE Publications Inc tit 16K STANDARD R - 285 KIT - 450 nsec. Ideal for SOL 20, IMSAI 8080, etc.

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Circle 318 on inquiry card. BYTE December 1978 115 V0- instruction OGEE to return control to the Torpor., rr401. 111- Seers l00M.Mr11 instruction following the 2MMM. You can 112- Roo. manus 100 lit swat nest these subroutines. The OMMM instruc VO- Score x 1291 V4- Icar. Y 1191 tion a machine language subroutine permits 116- UFO Ir MO et styli to be inserted if required. V6- UFO ylo61 112- Rock.11l Ir.rdom, OF is 2E1 VS- RusSO n lu ii civil Designing a Video Game Program VS- RockM tired lap 100-ro. 01-ved A detailed example how vA- Sar. Ncr.mml loo or 011 will illustrate VF- He Ilea t000r011 easily the CHIP8 language can be used to program a real time video game. The first Table 2: Rocket program ...lodes. VB, VC, step always involves specifying the video VO orni VE are notusedln this program display and the functions to be pro. grammed. Figure 3 shows the display format chosen for this game. An enemy UFO teil rocket counters, as well as the X and Y CO. be constantly moving from left to right ordinates for the target UFO and on screen across the top of the screen. A single digit score digit. The UFO pattern is shown on score will be displayed at the lower right. the screen so that it can subsequently be A rocket ship teil appear at a random moved. In step 2 the latest score is town horizontal position along the bottom edge on the screen, and V2 is checked to see if You launch this of the display area. can the game should end because nine rockets key F on the hexadecimal rocket by pressing have been fired. keyboard The rocket wil then move ser. Step 4 performs the operations required tically toward the top of the screen. When it to show a new rocket at the bottom of the reaches the top or hits the target UFO it screen. The rocket count is incremented by will be erased and a new rocket wil appear l for each new rocket. The rocket pattern at the bottom of the screen. After nine Y coordinate is set to hexadecimal IA so rockets have been launched the game ends that the rocket will appear at the bottom of and no new rockets will appear. If you hit the screen. The rocket X coordinate is et the UFO with a rocket the score is incre to a random value between hexadecimal OF mented by 1. and 2E so that it will appear at a random After specifying the positions of the horizontal without interfering with various game patterns on the video screen position the score digit. The flag V9 is set to 00 to as shown in figure 3, you must decide on indicate that the rocket has not yet been how the 16 variables will be used in the fired The rocket is then shown on the program. Table 2 ilustrates how we will screen and the program proceeds to the use the variables in this example. Six van. loop containing steps 3, 6 and 7. ables (V3, V4, VS, V6, V7, V8( are needed This loop causes the target UFO to con. to specify the X and Y coordinates of the tinuously move across the top of the screen three types of patterns involved (score, while waiting for key F to be pressed The target UFO and rocket(. We need two more UFO is randomly moved zero, one, two or variables (VI, V2) to keep track of the cur. three spot positions to the right each One rent score and number of rockets launched. the loop is executed. This gives it a rather V9 will be used as a flag that shows whether fast, randomly varying rate of motion, ma or not the current rocket has been launched. king it hrder to hit. The movement of the VA will be set to 01 if the rocket hits the UFO merely involves incrementing its X UFO fie: point scored( and VO will be used coordinate (VS). When VS is incremented for a working register er the program. VF is past the right edge of the display area, wrap the hit flag and is automatically set to 01 around automatically occurs so that the when a hit occurs. UFO reappears at the left edge of the display area. This wrap around automatically occurs Flowcharting the Game when any X or Y coordinate of any display

I believe you should always construct a pattern is incremented or decremented past detailed flowchart, such as Me one shown in any edge of the 64 by 32 bit display area. figure 4. Proper flowcharting will save hours When key F is pressed to launch the of debugging and oil simplify making future rocket, step 6 causes V9 to be set to 01. changes to your program A flowchart also Step 7 then causes step 8 to be included in lets you see the major and minor loops in the loop. Step 8 checks the value of the sys your program, allowing you to avoid timing tem real time clock (or timer) to see if it has bugs that can occur in real time situations reached 00 yet. When the timer reaches 00 such as video games. the rocket is moved up one spot position, Step 1 involves initializing the score and and the timer is reset to a value 0(03 (1120

1111 e.aw..snro.nerkka..I. TARBELL SOFTWARE Extensive & Inexpensíve. TARBELL CASSETTE or DISK BASIC only $36.00 Most features of ALTAI R* Extended BASIC are includ- a logical device Drop an I/O channel previously assigned PLUS these added features: ed Cause programs to be appended onto programs al- Assignment of I/O ready in memory Call a procedure and pass variables on Alphanumeric line labels are allowed the list Cause interpreter to enter edit mode using 15 Read and string data write single character edit commands. Unlimited length of variable names and strings Procedures with independent variables Tarbell BASIC occupies 21 K of RAM. Number system 10 digits BCD integer or floating point Tarbell BASIC on cassette - $36 Tarbell BASIC on CP /M Disk - $36 Included are commands unique to Tarbell BASIC which Tarbell BASIC Source on paper - $25 provide capabilities to: Tarbell BASIC Source on CP /M Disk - $25 Chain to another program Assign a physical device to

CP/M Disk Operating System BASIC -E Compiler The I/O section of this software has been modified Designed to work with CP /M Disk Operating System to operate with the TARBELL Floppy Disk Interface in this software requires a total of 20K bytes of memory. 24K bytes of memory. Five commands permit listing of Included are 26 compiler error messages and 23 run -time directory, typing contents of an ASCII file, renaming error messages. Disk files may be read, written or up- a file, erasing a file from disk, and saving memory on dated by using both sequential and random access. In- disk. Fourteen programs are included which are invoked cluded are blocked and unblocked files. Price for com- like commands. Six source files are included for transfer- piler and run -time monitor on diskette is $10.00. Manual ring between TARBELL Cassette and disk, cold -start is available separately for $5.00. (Public domain soft- loading, Basic I/O system with drivers, and reformatting ware by Gordon E. Eubanks, Jr.). crashed diskettes. Documentation includes a listing of BIOS and instructions to patch CBIOS for your system. Price is $100 on CP /M diskette with documentation. CBASIC Pmgramming System (CP /M is a product of Digital Research). Upward compatible from BASIC -E, CBASIC is similar but expanded to include several business oriented facilities, allowing decimal computations to 14 digits of CP/M 1.4 Update Package precision, data formatting and PRINT USING state- A TARBELL Update Package for those now using ments. Statements allow access to disk files and disk CP /M 1.3 is now available on diskette. The Update file maintenance. Strings of characters may be read from Package adds new commands and the ability to access the console to permit correct input line format to be four disk drives, as well as 2 new CP /M manuals, TAR- checked before reading data. General programming fea- BELL CP /M User's Guide and a new BIOS listing. tures include variable names up to 31 characters, option- Price: $50.00. al line numbers, dynamic debugging tracers, and optional data output to printer. CBASIC on diskette and manual priced at $100. (Copyright Software Systems.) SPOOLER This 8080 program will save many hours of computing time. It intercepts all output to the list device, spools the EMPL-an 8080 APL a high -speed output to disk file, and directs the spooled Especially suited to educational applications, EMPL a -speed data to low printer during unused cycle time while is an adaptation of APL, using the ASCII character set. the CPU waits for transfer of data to and from the console. Only one -dimension arrays are allowed. This 8K version System throughput is greatly increased with the aid of occupies the first 5376 bytes of memory and operates in SPOOLER. Output is never lost due to insufficient memory two modes. The Execution Mode permits all instructions allocation. Fully compatible with the CP /M file system, to be executed immediately. The Definition Mode per- SPOOLER permits parallel processing without hardware mits the user to enter functions. EMPL on Tarbell Cas- interrupt, and with minimal impact on other processes. sette with manual is $15. (Copyright 1977 Erik Mueller). Price: $70.00 (Copyright KLH Systems.) " ALTAIR is a trademark /tradename ofPertec Computer Corp. "'CP /M is a trademark /tradename of Digital Research

950 DOVLEN PLACE SUITE B CARSON, CALIFORNIA 90746 (213) 538 -4251 (213) 538 -2254

Circle 360 on inquiry card. BYTE December 1978 ÍÍ7 MOVE UFO Figure 4: Flowchart for rocket game. RANDOM (0.3) SPOT POSITIONS

STEP 5

START

ROCKET STEP 6 FIRED INITIALIZE FLAG 01 VARIABLES

STEP I

DISPLAY UFO PATTERN STEP 7

STEP B DISPLAY SCORE

STEP 2 STEP 3 MOVE ROCKET UP ONE YES SPOT ( STOP ) POSITION STEP 9

YES INCREMENT ROCKET COUNT

SCORE TIMER 03 INCREMENT ROCKET Y. IA 01 ROCKET X. RANDOM (OF, 2E) STEP 10 STEP 12

TONE 03 SCORE STEP 4 INCREMENT00

ROCKET ERASE SCORE FIRED ERASE ROCKET FLAG 00

STEP 11 f

ADD SCORE DISPLAY INCREMENT ROCKET TO SCORE

118 December 1978 ()BYTE Publications Inc THE MICROCOMPUTER SOFTWARE STANDARD

CP /MTM OPERATING SYSTEM MACTM MACRO ASSEMBLER Editor, Assembler, Debugger, and Utilities Compatible with new Intel Macro standard For 8080 and Z -80 Systems Complete guide to Macro Applications Up to four IBM -compatible floppy disks Documentation includes: SIDTM SYMBOLIC INSTRUCTION CP /M Features and Facilities DE BUGGER CP /M Editor Manual CP /M Assembler Manual Symbolic memory reference CP /M Debugger Manual Built -in assembler /disassembler CP /M Interface Guide CP /M Alteration Guide TEXTM TEXT FORMATTER Powerful text formatting capabilities Text prepared using CP /MTM Editor 11 EJ JE3JTEIL FEEiEflhC-1

Please send me the following: NOTE: Due to the proprietary nature of CP /M" software, please CP /M" System Diskette and Documentation (Set of 6 enclose your CP /M Serial No. when ordering MAC, SID, or TEX manuals for $100. without the CP /M diskette. CP /M" Serial No CP /M" Documentation (Set of 6 manuals) only for $25. BankAmericard No. Exp. Date MAC" Diskette and Manual for $90. Master Charge No. Exp. Date SID" Diskette and Manual for $75. Check or M.O. enclosed. TEX Diskette and Manual for $75. California residents add 6% sales tax. Send information on CP /M User's Group, high level Total amount of purchase $ languages and optional packages. Name Address City State Zip i I1E3TflL hEEiEflFIII-1 Post Office Box 579 Pacific Grove, Calif ornia93950(408)649 -3896

Circle 95 on inquiry card. BYTE December 1978 119 second). This timer reset value determines the speed at which the rocket moves upward. The larger the timer value, the slower the rocket moves. The loop comprising steps 5 thru IO keeps both the target UFO and rocket moving on the screen until either they touch each other (a hit), or the rocket reaches the top Of the screen without touching the UFO. Address rocket other, IRexadecimall Instruction Pseudocode Comment. If the and UFO touch each step 12 is executed. This sets VA to 01 and t-. 0200 6100 V1 -00 stn score sounds a short tone so the player knows 0202 6200 V2 -00 Rocket coati 11 is 02D4 6338 V3 -37 Score x 9)19 scored. Step then executed to 0206 6418 04 -le Score Y erase the rocket and the current score on 0208 6500 v6400 UFO x screen. Step 11 also increments the score 020A 6608 V6 -08 UFO Y 020E A27E -0216 UnOwlern variable (VI) by the 01 in VA. The profane 020E D663 SNOW 3161I00606 UFO Den returns to step 2 where the updated 0210 226A DO 026/5 Stan 2: Snow score is less 0212 4209 SKIP; V2 Mt 09 score shown on the screen. If than 0214 1214 GO 0214 Sian 3 End loop nine rockets have been fired, a new rocket 0216 7201 V2.01 slan4: is shown on the screen in step 4, and the 0218 681A vu 41A Rocket 021A 6.400 54-00 step 5.6'? I op repeated as before. 021C C71F V) -FIND 17 theDhe rocketr reaches the top of the 0700E ROCkm x 021E 770E screen without touching the UFO, step 10 0220 óe 00 v9400 8 0222 8 :.0278 Rocket swoon will branch to step 11 causing the score and 0714 0706 SNOW 6MI111V7V8 rocket to be erased. In this rase VA coal 0226 427E 1.021E Stan 6'. UFO mown .attain 00 stepSet 4)4 so that the 0228 3563 SNOW 3MIW Erae UFOFO ( from score 022A 0003 v04RND coil remain unchanged. Note that the entire 0220 8604 v64v6.v0 Sol VF program has now been designed. By double- Mt 13563 SNOW 3M4V6v6 Checking the programrogr m A 0230 3200 00026f GO OO 8 flowchart form, 0232 1262 600262 50012 it nn you Can eliminate almost all program bugs VO.OF 0234 600E Stone.. before they occur. An extra hour spent on 0236 E001 SKIP; VO NE KEY 0238 6901 V9.01 the flowchart can eliminate many hours of 023A 3901 SKIP: V98001 Sian). debugging later. All that remains now is to 023E 1226 600226 Sranó translate the into an 023E 100] GO0226 Sep B'. flowchart appropriate 0240 1000 SKIP; v0E000 sequence of CHIP-B instructions. 0242 1226 GO 0226 Ran 6 D244 A276 1.3278 Sep 9. Flockel WORM 0246 1378 6 SNOW 6Manv)v8 Ern. rocket Coding and Debuggingggi g the:inal Program 0248 071=2 SNOW The final program is shown in figure 5. 0240 13)00 SNOW 6V)V8MW 8r 8 o24c 3200 SKIP; VP EO 0o To translate the flowchart into CHIP-8 024E 1262 GO 0262 Stan 12 instructions, start by listing evert numbered 0250 6033 v0403 Slan 10: 0252 F015 TIMEVO hexadecimali l memoryory addresses in the first 0264 3803 SKIP; v8 E000 column, as shown in figure 5. Fill is the 1226 Step 12 0266 000226 third column with an abbreviated dasvrhp 0268 226A D0 02131 Sop 11: Erne score D264 A778 1.0278 Rocket pallem tion of the func0on to be Performed by 026C D786 SHOW 6M1 0700 Erne rocket each instruction. It is usually most co.. 814A vlVNVA 026E 5core.VA venient to locate subroutines and pattern D260 1210 000210 Stan g D267 6.401 vA401 Ran 12: byte lists at the end of the program 0264 6003 w 403 Labeling the appropriate program addresses 0266 2018 r074E -v0 0268 1268 GO 0258 SNP 11 with the flowchart step numbers will also 026/5 AZAO I =0290 SSS: 3brNwprt wen prove helpful. The actual hexadecimal 0260 0133 MI-V113001 codes for the CHIP -8 instructions can then 026E 4242 1 -02/52 Lees. significant digit 0273 F065 VO. v04MI be written in column 2 and entered into the 0272 0029 14VO ILSOPI COSMAC VIP memory using the hexa 0274 D346 SNOW 6MIIIIv3V0 decImalk board. 0276 OGEE REV ey 02)8 2070 ROCK. To debug the program, replace the 4209 02]/5 7028 Rocket pattern instruction at memory location 0212 with 0270 008 D27E 7C06 UFO: UfO Paunn a 1212 branch instruction. When the pro- 021:10 )COO gram runs, it will stop at location 0212 since the 1212 branch loops on itself. If figure 5: The rocket pogrom code /n CHIPS hexadecimal interpretive the UFO and a 0 sigh initial score show on language Instructions. The steps spec /fled relate directly to the flowchart the video screen, you know execution was given Tor the game In figure 4. proper up to location 0212. Replace the sip u, m5Onrcr aus.ok "My Structured Systems business software has paid for itself in labor hours

Ken Tunnah is one of many innovators saved alone." bringing the micro Mr. Ken Tonnah, Colloid -A -Tran Inc., Buffalo, New York revolution to the small business. As a programmer, he knows computers and their languages. As a businessman, he knows business and its languages. And when Mr. Tunnah decided to micro- computerize the accounting function at Colloid -A-Tron, he turned to Structured Systems software.

Says Mr. Tunnah: "The program is designed The software is designed to run on an 8080 or Z-80 from a CPA standpoint, for multiple corporations, CPU with 48K of memory, dual disks with CP /M ®, which we have. It is flexible and gives me the printer, keyboard, and CRT To make it all work for you, ability to change reporting by profit centers we have provided the most extensive documentation easily. It is up and running quickly, and it just and support in the industry. keeps on running. I think it's the best business We provide the capability to computerize complex software available." accounting functions on relatively inexpensive micro- The best software available. That's what Structured computer equipment. Ken Tunnah has told us what that Systems Group set out to create. means: "I've bucked some trends. I looked around, Structured Systems offers three sophisticated and decided that with the right software, I could accounting systems. Our General Ledger software is get a micro to outperform a $45,000 mini. I'm big enough for multi -client write -up by the CPA, or satisfied. It's simple economics." multi- corporate reporting for the business, but small We can refer you to a growing number of sophisti- enough for the micro budget. The very comprehensive cated retailers experienced in Structured Systems Accounts Receivable and Accounts Payable packages Group business systems. Or we can work directly with will operate independently, or they will coordinate with you. We'd be happy to provide you with more informa- the General Ledger. tion on our product line, which includes QSORTTM (a Our systems record transactions easily and cor- sort /merge program), CBASIC (a business BASIC), rectly, and provide an audit trail from source document NADT" (a mailing and addressing system), and our to financial statements. And they will maintain monthly General Ledger, Accounts Receivable, and Accounts and year -to -date information in dollars and in Payable packages.

percentages. And they are reliable. ' CP /M is a registered trademark of Digital Research The three systems interact with the user to set up parameters such as PGPP format and headings, account titles and numbering, I tructured /totem/ Group automatic billing or reminder INCORPORATED notices, credit limits, sales 5208 Claremont Avenue reports, a check register, Oakland, CA 94618 and much more. Call us at (415) 547 -1567. Or write Dept. B7.

Putting the Microcomputer in Business.

Circle 351 on inquiry card. BYTE December 1978 121 Program faster, 1212 branch with the original 4209 instruc- debug easier now tion and put a similar idle loop branch further down in the program for the next FlowchartrixTM a unique flowchart development tool from Stirling /Bekdorf, test run. In this way you can identify which saves you time, space, and money, no matter what language you work with. Whether you program professionally or just for fun. The 18F2 FlowchartrixTM program steps are causing a problem. If you helps your thoughts move in logical steps, and lets you retrace logic easily need to change any portion of the program, when debugging. a a When you use "top- down" programming methods, you can use the 18F2 just insert branch instruction to patch to lay out your original logic concept blocks. Then by following the plan added at the end. Designing, coding and you lay out in words at the concept stage, you can write a finely detailed debugging this simple game program re- flowchart quite smoothly. Then it's easy to write actual code based on the flowchart. quired about eight hours. Actual coding and 54% more logic cells than other flowchart forms, so you get far more loading the program into memory required of your program on each page. Each Flowchartrix has a full 11 logic cells, less than an hour of this time. not just 50. This not only saves paper, but also makes your finished flowcharts easier to understand. By seeing up to 21 extra steps of your program The sample program was kept simple for on each page, you comprehend program flow more clearly. That's important ease of understanding. Even in this simpli- while writing the flowchart, more important when you write actual code. a Its also extremely helpful when you debug, and indispensable when you come fied form it is challenging game to play. back months or years later to modify your original work. 18F2's higher ma- The speeds of the rocket and UFO can be trix count makes your flowcharts quicker to debug because there are fewer easily adjusted to make scoring more or less pages to search for errors. Fewer pages also save you money and storage space. difficult. Adding multiple targets and Unique matrix can show your loops AS loops. The Flowchartrix 7 x 11 2 digit scoring is possible. Multiple rocket matrix gives you plenty of room to write loops laid out as sort of a squared launch angles or after -launch steering could circle. This makes loops and subroutines easier to recognize, because their form is readily apparent at a glance. Since they're easier to find, and may be incorporated. Exploding UFO patterns even be completed on a single page, they're also simpler to debug or modify. could be shown when one is hit. Every matrix cell has a specific label to help you track branch points. Now its far easier to follow your program from page to page, point to point. When you write program documentation, having a separate reference point Concl usions for each cell makes your program much easier to describe clearly. With Flowchartrix, you don't need a shape template to draw remarkably Hexadecimal interpretive programming regular logic symbols. Guides for the most -used logic symbols are right in provides an easy way to program small each matrix cell. They help you draw most standard flowchart symbols en- computers. This approach requires fewer tirely free -hand. This saves all the time you'd otherwise spend hunting a shape template and positioning it to draw every symbol. Your train of th- instructions and is much easier than machine ought need no longer be interrupted by template tedium. With 18F2, your language programming. On the other hand, pencil can fly as fast as you can write, without interruption. When a flash of insight strikes, now you can keep your pen on paper, flowing rapidly from hexadecimal interpretive programming re- one step to the next without a break. quires much less hardware overhead cost 18F2 is surface-engineered to take both pen and pencil without blotching. than do high level languages such as BASIC. The tough 22: base stock is the same brilliant white opaque material used in our 18C1 Combination Coding /CRT Layout forms. Pure enough to use A detailed example was provided to with magnetic ink scanners, heavy enough to withstand vigorous erasure, illustrate this interpretive approach for a real every Flowchartrix gives you crisp, sharp, characters and symbols. It takes time video game. The RCA COSMAC VIP ink without spreading, and accepts soft pencil lead with good contrast. Order your supply today. Ask your local computer store for Stirling/ and CHIP -8 language were used in this BekdoriTM78F2 FlowchartrixTM To enjoy the world's most advanced program example, although other hexadecimal inter- development aids most, use the entire Stirling /Bekdorf system: 18F2 Flow- pretive languages are possible, and a similar chartrix (for concept planning and flowcharting), 18C1 Combination Coding/ CRT Layout forms (for coding and display planning in BASIC, OPUS, and approach can be used with other other line- number languages), and 18P4 Print -Out Design Sheets (to design microcomputers. The steps required in report printouts for easy coding). Our programming tools work together a language such as as a complete system to save time and reduce errors during every stage of programming with program development, from concept to completion. Try them for yourself CHIP-8 are the same as required when today. If your store is out -of- stock, use the coupon below to get yourself using any language: you must specify a supply on the way now II11 the functions required, decide on vari- r able and memory utilization, prepare a Y ES! Please rush the programming aids indicated below. flowchart, check the flowchart, do the 78F2 FlowchartriaT' 78C1 Coding /CRT Combination and two 50-sht pads S7 90 . S2 85 shpg vo 50 sht. pads $6.35 + S1 95 shpg detailed coding, load the code, debug ten 50 sht pads S34.35 + Sb 45 shpg El ten 50 sht. pads $26.85 + 53.35 shpg to the extent required to get the program 78P4 Print Out Designer running properly. Only the last two steps one 50-sht pad. + shpg. five 50-sht. pads + 75 shpg S7.45 S3.15 S32.10 S6 involve using the hardware. Skipping any I eras residents please add 55°. sales tar to base once Enclosed is my check for $ of the earlier steps will invariably lead to Charge to: [Waster Charge Visa exp. date excessive machine debugging time no mat-

Card = Signature ter what language is used. Dealer inquiries welcom e If you've never tried a language such as Name CHIP -8, you may be surprised at how easy Address Phone it is to use. If you have a limited budget City State Zip you will certainly appreciate the savings in We ship UPS so P 0 Soo address must give phone numb', hardware over conventional high level languages. Last but not least, you might even Stirling/Bekdoñ discover that designing your own hexadecimal interpretive language is also Lip 4407 Parkwood D San Antonio, TX 78218 C] (512) 824 -5643 fun.

122 December 1978© BYTE Publications Inc Circle 352 on inquiry card. 6800 Debug Package

TheTSC 6800 Debug Package provides a better way to trap program bugs. It is an extremely powerful and complete assembler language program debugging tool which is capable of simulating all functions of the 6800 microprocessor, including interrupts and I/O operations. WE'VE It is an ideal substitute for hardware logic analyzers or CPU emulators at only a fraction of the cost.

Any number of breakpoints may be user defined. Each breakpoint may invoke any one or combination of eight different actions. These actions may be dependent on a user defined condition such as register A =$FF or memory location $11355 =0. The actions may also be delayed or JUST limited by a pass count. Histogram breakpoints may be set to enable profiling of the executed program. Break- points may be set in RAM or ROM!

Complete simulation control allows trace mode to be enabled at anytime. During trace, registers and opcode mnemonics are displayed after each instruction is ex- BUILT ecuted. Single or multiple instruction stepping is permitted as well as simulation speed control. The trace back feature allows the past 256 executed instructions to be viewed. Program execution may be halted at anytime by operator command.

Memory protection and traps are another key feature. Any section(s) of memory may be write, execute, memory, or YOU simulate protected. Execution traps allow program exit on general conditions such as interrupt instruction, transfer instruction, subroutine nest count, and instruction count timeout.

General features include a line at a time assembler, disassembler, memory interrogation commands, hex A calculator, machine states counter, stack protection, register modifier, and mode control. In all, there are over 50 commands available. The manual includes detailed operating instructions as well as the complete com- mented source listing. Requires 9K at $3C00.

SL68-30 Manual and source listing $ 35.00 SL68.30C with KCS Cassette $41.95 BETTER SL68.30D with mini FLEX" diskette $ 43.00 SL68 -30F with 8" FLEXTM diskette $ 55.00

Send 25t for a complete catalog of TSC's assembler language software for the 6800, 8080, and 6502. BUG Technical Systems Consultants, Inc. Box 2574 W. Lafayette, IN 47906 Specialists in Software & Hardware for Industry & the Hobbyist TRAP Circle 370 on inquiry card. BYTE December 1978 123 Prof George A Garbata Who doesn t want a tutor who is infi- microcomputer systems will possibly cost Dept Of Chemistry nitely patient, expert on almost any subject less than 10 percent of minicomputer Wntetn Washington University under the sun, available at your beck and systems (using in as cases initial capital Baangnam WA 60225 call, adapted to your learning speed and outlay, the most relevant number for indi- style, and cheap? This has attracted the viduals or small institutions). What remains attention of a number of the manufacturers is to create appropriate software for team- of personal computers, and several of them ing with a microcomputer. make prominent reference to educational Before we attempt to write good teaching applications in their advertising. But the software, there are some rather fundamental customer who uses educational applications questions to be answered. First, what do we to justgy raiding the family budget for a mean by good teaching? A more useful computer will have some explaining to do, question might be, "What is good teaching for good teaching software on microcom- not ?" One relevant answer for computer puters is not available, nor is it easy to write. teaching is, "Good teaching is not just Why? testing." If you examine the 20 years of develop- Most programs described as teaching ment of computer assisted instruction (CAI) programs are programmed tests; the format on mainframe computers, you'll see that is exclusively question, accept answer, one the computer can be an effective teaching message for right, and a second for wrong. tool when used properly. Students taught Random selection of messages from a list with a computer perform as well or better may defer boredom a bit, but that feature than comparison groups; they may learn alone does not change a test into teaching. two or three times faster. Their failure Good teaching is not repetitious to the rate is lower and they express satisfaction point of boredom. That's an obvious state- with the technique. Why then is the tech- ment, but it poses a dilemma for those who nique not more widely used? There are three would teach with the computer, because main re3 sons. the efficient use of a computer usually repeated use of sections of code.de. Teaching The resolution of the dilemma is to write long and varied course software which can be used by a large number of students. With a Microcomputer Good teaching does not force each student to proceed by the same path. Addition of hints or partial solutions for every question on a programmed test does irst, teachers are conservative. In fair not make that program a god teaching ness we also must realize that teachers have program. If each wrong answer is diagnosed, heard too many extravagant claims for and a hint or partial solution which builds the miracle that this or that piece of edu- on the correct portions of that particular cational technology will produce; their wrong answer is given, then we may have cynicism is understandable. Proponents of a good teaching tool. computer assisted instruction have not Good teaching does not consist of a always been conservative (nor have they random collection of available bits and always been accurate). The cost of hardware pieces. This implies that we should think is also seen to be prohibitive. Exceptionsex- in terms of sizable units which can become ist, but the most visible lie: highly funded) significant components of a course or systems are costly to purchase or lease. subject. Third, the creation of high quality software Finally, we should not forget that good

toa difficult and time consuming task which teachers are most often experienced teachers this point has provided little compen- and that any occasional lack of enthusiasm sation beyond personal satisfaction. on their part about the teaching efforts of The personal computer will eliminate well- meaning parents is not invariably two of the reasons. Teachers are discovering misguided. computerscomputers through their own efforts and Another important question is, "What are stimulation provided by students we trying to teach ?" This question is espe- and parents who have computers in their cially important for the personal computer homes. The major price breaks in the cost user because the output devices commonly of hardware have resulted from the in- used cannot provide the notation which the troduction of smaller machines. Mini- students usea elsewhere. Books are not computer systems cost less than 10 per- written in only; exponents are cent of mainframe based systems, and usually written with arrows or double

120 orr..a,vnaeyn mambo. See the computer.

asterisks; yes and 1 are not synonymous, nor are no and 0; the answer to every ques- See the computer run. tion is not a, or b, or c, or d - none of the above. If we attempt to teach using devices Read The Computer Book. which impose notation limitations, we ask ourselves repeatedly, "Are we teaching This is it - a workbook that actually shows you how what we want to teach, or are we teaching a computer is organized, programmed, and run. How? how to use and cope with the limitations of Because the book is a computer! The Computer Book. the software ?" Here's how it works: the top third of each page graph- With these points in mind let us now con- ically represents a memory location (illustrated at sider computer languages for teaching. right) which includes memory and address registers Some teaching languages are based on a to be filled in by you, the reader -as- programmer. The teaching strategy; others are based on program steps are listed at the tops of the pages, and software functions. Our experience is that at each are the latter types are far superior to the for- location you given your next instruction(s) mer, for they allow implementation of a 67 to carry out. You play the variety of teaching strategies. Examination switch register and control of a large variety of good computer assisted circuits, a bookmark serves instruction materials shows that they are as the program counter, built from a small number of operations. and your pencil is the line For example, one must be able to send printer. Before you know text to and accept text from the terminal. it, you'll be "jumping to Call these functions type and accept (or subroutine" and "clearing T and A). (The notation herein is the PILOT the link" with the best of notation; for a more complete description them! More importantly, of the language see "Computer Assisted you'll understand exactly why you're performing each Instruction on a Microcomputer," November step as you run through the programs. Not even step- 1978 BYTE, page 90.) ping a real computer through a program can provide a Having accepted text, one must be able comparable learning experience - the reader is inside to analyze it. This is usually done with some the computer! type of a match (M) algorithm. One also needs some kind of jump (J) instruction, The text of The Computer Book is presented in such instructions for subroutine calls and returns a clear, down -to -earth style that it makes an ideal in- (U and E), and some kind of compute (C) troductory reference for anyone, student and non - instruction so that one can use the full technician alike, who wishes to improve his /her range of numerical and string operations understanding of the digital world. Contents include: normally associated with computers. Finally Number Systems and Codes Practice Programs one needs some way to make execution of Memories Assembly Language at least some of these instructions (at a Peripherals High Level Languages FORTRAN minimum, the jump) dependent on the What Goes On In There? The Instruction Set COBOL values of various variables or on the success Organization of the Computer Microprogrammed Computers or failure of certain matches. Programming Microprocessors The obvious question for the microcom- Thumbs -On Experience Microcomputers Our First Program Steps puter fan is, "Can I use BASIC ?" Unfor- Mal tunately, the answer is, "Only with extreme ARTECH HOUSE BOOKS difficulty." Typing text is no problem, and accepting input from the terminal can be 610 Washington St. Dedham, MA 02026 handled. Accepting an input of two when (617) 326 -8220 you programmed INPUT X and expected the answer 2 will take some extra code, but we've already learned that these are going to Please send me copies of The Computer be long programs by usual computer Book at $28.00 per copy. standards. The difficulties with accepting data pale in significance when compared to I enclose check or m.o. for $ the difficulties with match. MC # Exp. date Consider an extremely simple case: Name a question that can be answered yes. Write BASIC code which will match any of the Address following: City yes, Yes, YES, O.K., OK, Of course, State Zip Sure, Always.

Circle 11 on inquiry card. December 1978 BYTE Publications Inc 125 but which will not match any of these: By doing so we have shown that it is possible to implement a language that includes yesterday, yes and no, yes or no, all the operations necessary for teaching, Alyeska, eyes. including the full range of numeric and In a good teaching language it can be done string operators, full floating point, and in a single line. It could be done in BASIC, numeric and string arrays, all in a 20 K byte at least in a BASIC with a full range of string microcomputer. Moreover, the response time operators, but in practice no one bothers is excellent. We maintain that there is no

because it's so much easier to tell the student reason to settle for I ess in an instructional

to answer 1 for yes. One could program the language. match algorithm of a good teaching language Now that you're convinced that you'll in BASIC as a subroutine, but the resulting have to get better systems software, what code is too slow. It seems then that BASIC about hardware? It appears that any of the (and other computational languages, such standard microcomputers will be suitable for as FORTRAN and APL) are not suitable this application if they can accept sufficient for this purpose. memory (16 K to 20 K bytes). The length of Fortunately one of the best teaching lan- instructional programs and the distance and guages, PILOT, is well suited for microcom- complexity of branching within the program puters. The original form of PILOT is too requires the use of floppy disks or other limited for production of top quality teaching forms of mass storage. materials. Several extended forms of PI LOT A typical intructional dialogue program have been developed, and the National occupies about 8 K bytes for every 5 minutes Library of Medicine is supporting an effort of instruction. Any individual student might to achieve a national standard for the ex- leapfrog an entire section in a few seconds if tended language. At Western Washington the program were written to move with a University we have implemented what well -prepared student. Thus the system must promises co be essentially this standard on a be interpretative, with the programs stored SwTPC 6800, and we are currently working on disks. on 8080, Z -80 and Pascal implementations. Good terminals for teaching should have good graphics capabilities. At this time such terminals are too expensive ($4000 to $6700), several times the cost of the rest of the system. What is needed is a video terminal with at least a 256 by 256 dot matrix NOW ! that can be superimposed on a 24 line by 80 character display (upper and lower case). LOW PRICED EIA RS -232 Until such a unit is available, we must make do with less. However, a 40 character line is CABLES IN STANDARD rather short for this purpose. LENGTHS Finally, after all these cautions and dis- couragements, what can or should the owner of a microcomputer who wants to use the thing to teach do? One possibility is to search for or create games which provide practice in topics which your children have already learned in school. An obvious example is a version of Spacewar that demands fractional inputs as an exercise in fractions. A second possibility is the purchase of suitable systems software and course mate- IDS now supplies quality order necessary. Just rial. Such material is beginning to come onto cables with male to male, phone or mail in your male to female, or female orders. Special cable the market. The third and most exciting to female connectors in 5, configurations also possibility is to become involved in creating 10, 15, 20, 25, 30, 40 & 50 available. Immediate teaching material. Get suitable systems foot lengths. No minimum delivery from stock. software and find an interested teacher. The teacher provides the material and the ap- 1111 ON GSA SCHEDULE proach, and you provide the programming. If you take this route, remember that the teacher knows how to teach, that students 7 Wellington Rd., Lincoln, R.I. 02865 in INTERNATIONAL are more varied than your imagination, and Tel: 401-333-6200 DATA that good materials require testing and TWX: 710 -384 -1911 SCIENCES, INC. Export: EMEC, Box 1285, Hallandale, Florida 33009 editing and retesting and reediting.

126 December 1978 © BYTE Publications Inc Circle 184 on inquiry card. when software counts 485 Lexington Avenue 750 Third Avenue New York, N.Y. 10017 r I I - I I - 1 1 1 1 1- es - e ex , 1 l COMPUTER FACTORY PERIPHERALS APPLE II FOR PET APPLE is a completely contained compute, milk BASIC 32K Memory Eaoanuon 5555 anum, in ROM, lull ASC 1I keyboard in a 151( EKPANOAPET 5475 lipthvetghl molded carrying tau. Expandable to 4 8K PET to R5232 Senti . S169 2 Way Serrai /Commumc+non 5295 APPLE IT Syllem I1Om 5978! APPLE only Modem lot PET,._ 5775 IT Disk...... _ ...... 5595 $795 PET to 510014 clad.., 5160 APPLESOFT in ROM ...... 5200 Intellace . 14K ROM Operaunp System Sound Effects/Mom Boa S 35 Cards ...... __...... 5179 8K RAM Memory Second Canette Ono, S 99 9" Video Mondo Parallel Primer Interlace 5199 MICROPROOUCTS Burls In Keyboard PET Printer lr en '791 5695 Mortally controlled tape DUAL DISK EPROM Sodes Ados...... S 14.95 Cz commodore Today % bet valve in personal computers a she n peripherals are (200KB) always us stock al she COMPUTER FACTORY $1295

PRINTERS PRINTERS Qo The COMPUTER FACTORY', extensive CENTRONICS 119 $1045 SOFTWARE inventory and vade stlect10e of compute. AXIOM IParallell 5 395 primers assures you of ImdPm.g the pm AXIOM 15ewall. S 495 hest toted lo yOul npdt and spenl.al.pit EKPANOOR ITraclar,l S 425 BUSINESS AND FINANCE The Inlloynn, EDUCATION primers work well with all INTEGRAL DATA S 195 known personal compute OUME or DIABLO 57400 STOCK PORTFOLIO ANALYSIS PACK. value and lulure value of bards, eReehve 11851C 11851C Areal tulplN playa, .n ANDERSON AGE' Track your stock 0011101.0 lM Indent weld. and oases puce of hoods 51295 linducm5you Io PET'. BASIC 514.95 JACOBSON analysis. 574.95 CHECKBOOK: A cash recepa and isbrnse SORCERER OIET PLANNER ANO BIORHYTHM: events program that we1l1 make.I a breeaelo WORD PROCESSING FOR PET' Wish this keep accounts and up to l em moats Do decant your ideal we.ghl. Ihen c+ program In hard, can crease sex, and you Checks can be searched and suo9d by own lases calories needed 514.95 add, delete, censer, recall hoes and move log use. letmel caviares 51595 and on page re between page Use BASIC MATH PACKAGE Includes lour PET or ,,shin termin+l keyboard 545.N FINANCE A variety 1100.1uí bNneral for programs Ma.a Math Rool.nes. Vector MORTGAGE CalcAals computes., mules one easy e program Ardhmer.c. 1119ononletry. and Calcolus rmrlgage infoorahoo when povlded sub Includes Compound interest, Orseour. 529.95 beet data. 515.95 by FAIRY Nom,A and Eh leeswe poems', Anniehes. Loa, Oepe[.at.on SIS95 5502 ASSEMBLER IN BASIC' 0 COBSON 2.80 Praetor $895 ANNUAL REPORT ANALYZER. W.M An Pariah( 6502 nn.uCEOC mnemonics, Keyboard and Nume.n Pad PUN Reppl in haud,you ..put revenueand pet MO Wps. and addresnngmodes. Uses PET 841 LID Terminal n BK RAM (up t0 DATA BASE 517501 PER YEAR 157000 32KI mcorne hives for the prewnusl.veyearB, monthly lapel hue umber and rursur edning lavons Ideal lot ward pmcnlmg and small bin. Serval and Parallel Il8 Per well as basic Balance Sheet data 524 95 Ineludn c over 2.500 maim esses Duca Calmer/CI River, cnmp+les Percentage year loyer cal 11 r ASC 11 Smelts the New York AmreaP Code 30 a 64 Display Ç nwm .n ,ale ,, and earwigs For PET and Apele profits. pe r and Over Ire Counter ee.N.l9es Data Base Ill 15 cps Pr.n10o1 5.100 Compatible han. Average and compound EPSover lee 1 1 1 lapes re uprtawl monthly by Pack e 10 BUIIOER SERIES 3 0 Adult/ HO Nara, Select...1 Printing 64 User Deleted Charade., years PE r+ nt, Profil margin Ior previous Teaches changes 10 BUILDER ANALOGIES: Use Keyhrald Irr PET 240 a Resolution 512 Grelhib Ive yeas .11 graphic display pal dors method of solving wnrd analogy problem Reharie heavy duly Mechanism Modular design alloys use 01 both c=Ma11M rev awns) prole margins: Curren, Mrghschool through +dolt 59.50 Completely Refurbished by Al STOCKSCREEN This program allows 11111 lot programs and ROM PAC eartndp5 lot mnuBook Return on equity, Debt va, in screen the 2500. stocks n. the National Sew.ceul 15 Malm Cores futura Impwa introductions like; APL, o etiorly rano IlPay0u1 ratio, O,udensy.eld. 10 BUILDER - VOCABULARY Provides Sera! Pera1e1 Corporate sc i OATA BASE he any COBOL. PILOT, FORTRAN. arc. Add noni Implied growth ra e. Implied total return; for 000alu4M5 Iesl.ng using s5no ombro+ on equ.Iy. Yield pxlrce Hof and tape or disk for compete complier Theoretical PE ratio. Theoretical value nwm ana aionym 2 tape, H.gh school $1195 $1095 Payout ralo . h rplrel growth ta e PE re. system. ,sock 572.55 to Nun 517.50 Percentage growp, Oehl In erhniy rat STOCK ANALYZER We rile ve4h Data Current ratan 52995 Basel CompucolorII The pogrom IS essentially the same as An OPTIONS The Nadal Coronale Seminars nual Repart Onalyeer, emcee, em Su o versa. nl ere Bank Schules ,Ration, rum miornancany lead from Gare Pam tapes putes the theael.ral value o .r uohun simply by enor.ngticker symbols 57495 Value el option e giaphuelly I depned by $1'495 CompM1 movement is Pock pun and days so eau, 16K Model add 5700 BONOS: A vaneq olbond pegeam te Cl ahan 52495 cutete rntemr ate plu ro m 151111, goetenl COMPUCOLOR II Dai Based Model 3 Radio Advanced hardwereand software sechn0log VMS you: GA MES 13 inch Color Display 10 BUILDER NUMBER SERIES- Develops Advanced Color Graphics BLACK JACK JIM like Ln Vngn, rte l'El Shack a method of problem solving sedh polo. 51K Disk Built ln deals you Iry ln beat pen home 5995 n problems of uareasm9 ddhcuky 14gh 16K ROM Operating System school to Null 55 51 The following program Iules are now aval BK RAM User Memory SPACE FILMT 5995 ado for RA010 SHACK TRS 80 Corn 4K RAM Rehash PRESCHOOL IO BUILDER Teaches corm SPACETREK A leek' 011.10. (See above for don.pl.onsl 8080A Mrnocmpuler vaunnul'Ski, w e skdlt Includes TAME AMU DIFFER are. rimrr.nrk 59 re. 515 132 I/O ENT and LETTER BUILDER Wdh Parent's Every unit comte wish en extended DISK f0 BUILDER ANALOGIES S 9.50 PUCOLOR II Ms Ine power to handle corm Guide F or ages 3 to 6 D951 BACKGAMMON Yahae all Bran Sir..n BASIC that he a lull file management carra O BUILDER VOCABULARY 12.54 pie. tasks and small business aPPIrcationy 51495 brl.ly resident in the COMPUCOL OR II in 10 BUI LOER NUMBER SERIES 9 51 An impressive sollware library supplements STEP BY STEP Teaches how e 0119,mm 16K of ROM. 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THE COMPUTER FACTORY . a a when software counts 485 Lexington AvenL-d 750 Third Avenue New York, N.Y. 10017 (212) 687.5001 (212) PET -2001 Foreign order desk - Telex 640055 Open Tu -Fr 10-6, Sat 10 -4 J

BYTE December 1978 127 Mike Weed Digital integrated circuits that multiply bits in the multiplier times the number of Rt 2 Box 97A binary numbers without the use of clock bits in the multiplicand. Spring Valley MN 55975 pulses have been available for several years. Multipliers are readily constructed from One such 4 bit by 4 bit multiplier is illus- simpler integrated circuits. A 4 by 4 multi- trated in figure 1. The 8 bit product appears plier is illustrated in figure 2. The four bits on the output lines about 40 ns (the propa- of the multiplicand are gated into the adder gation delay) after the input lines are set. M places from the right if the Mth bit of the Larger numbers may be multiplied by first multiplier is 1. If this bit is 0, only 0 is sectioning the inputs into 4 bit words, form- added in. The parts count is minimized by ing the products of each word of one input bringing the carry output of the last adder with every word of the other input, and back to a previous adder input. This system summing these products in the appropriate costs less than the circuit in figure 1. Its manner. The propagation delay increases disadvantages are a higher components approximately linearly with the number of count and a 60 percent increase in power input bits. The number of integrated circuits requirements. The two systems have com- required increases roughly as the number of parable propagation delays.

Clockless Multiplication and Division Circuits

Figure 1: Commercially MULTIPLIER MULTIPLICAND available 4 by 4 multiplier. A3 A2 Al AO B3 B2 BI BO nnnn Dono

15 2 3 4 7 6 5 15 I 2 3 4 7 6 5 20 2C 2B 2A ID IC IB IA 20 2C 2B 2A ID IC IB IA

14 14 GA GA ICI IC2 13 74284 13 74285 GB GB

Y7 Y6 Y5 Y4 Y3 Y2 YI YO

12 9 10 12

P7 P6 P5 P4 P3 P2 PI PO

PRO CUCT

128 December 1978 ©BYTE Publications Inc MULTIPLIER MULTIPLICAND

A3 A2 Al AO B3 B2 BI BO U O U

1 2 5 10 12 131 l 10 I I 4 9 2 4 5 9 12 13 2 4 5 9 10 12 13 r 1 2 4 5 9 10 12 131

Cid I

i I I ;IC600000 IC7 IC8 0 0 0 0 0 00 IC9 0 I 6 II L7408 3- 8 8 7408 L7408 3 6 8 II 3- 6 8 7408 11 L 3- _J

I 16 3 4 8 7 10 16 3 4 8 10 i7 1 A4 B4 A3 B3 A2 B2 Al BI A4 B4 A3 B3 A2 B2 Al BI IC3 7483A IC4 7483A 14 13 14 13 C4 CO E4 E3 E2 El C4 E4 E3 E2 EI CO

15 2 6 15 2 6 9

16 3 4 8 7 10

A4 B4 A3 B3 A2 82 Al BI IC5 7483A 14 13 CO C4 E4 E3 E2 E1

15 2 6 9

0 o b P7 P6 P5 P4 P3 P2 PI PO

PRODUCT

Figure 2: Inexpensive 4 by 4 multiplier that has a higher number of integrated circuits and uses more power than the circuit in figure 1.

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Circle 203 on inquiry card. December 1978 © BYTE Publications Inc 129 The circuit in figure 3 shows one of many way to obtain a 4 bit quotient from a 7 bit possible variations along these lines. This 4 dividend and a left- adjusted 4 bit divisor is by 5 multiplier uses inverters and NOR gates shown in figure 4. A subtraction is per- on the inputs instead of the AND gates of formed at each stage by complementing the figure 2. Desirable input buffering is thus divisor and adding, while forcing a carry provided at about the same dollar cost, but input to the adder. If the difference is nega- requires more packages and power. tive, as indicated by a 0 carry output, a 4 bit Clockless division circuits are more com- 1 out of 2 multiplexer is set to transmit the plicated than multiplication circuits. One minuend to the next stage. If the difference

MULTIPLIER MULTIPLICAND

A3 A2 Al AO B4 B3 B2 BI BO r--- r--- 9 II 131 IC37a j5 (9

II Vd IC36 d e 7404 IC37 gb Vc I 1 7404 7404 8 10 6 0 L___ - L___ -

- -1 F- -1 E- I 2 3 5 6 8 19 12 1 2 13 6 8 9 121 2 I I

ll I IC14 l')-3;1 1C15 IC16 IC17 I I I I I 17402 4 10 13 7402 10 13 I 7402 10 I3 7402 L------_J L__ _J L J L_

3 4 8 7 10 f' 16 3 4 8 7 10 A4 B4 A3 B3 A2 B2 Al BI A4 B4 A3 B3 A2 B2 Al BI ICIO 7483A ICII 7483A 14 13 14 13 C4 E4 E3 E2 EI CO C4 E4 E3 E2 EI CO

15 2 6 9 15 6

I 16 3 4 8 7 10 III 16 3 4 8 7 10

A4 B4 A3 B3 A2 B2 Al BI A4 B4 A3 B3 A2 B2 Al BI 3 14 CO C4 IC12 7483A 1C13 7483A 13 CO E4 E3 E2 El E4 E3 E2 E1

15 2 6 9 15 2 16 9

P8 P7 P6 P5 P4 P3 P2 PI PO Figure 3: 4 by 5 multiplier with buffered inputs. PRODUCT

130 December 1978 © BYTE Publications Inc CA Osborne & Associates BUSINESS SOFTWARE FOR MICROCOMPUTERS

Osborne £t Associates is publishing its business systems in book form. These systems represent five years of development and testing by OEtA programmers, and the books include more than a year's worth of extensive and detailed documentation.

NET PRY What systems are we selling? OTRL 0 00 PR 86 560 25 821 1) PAYROLL WITH COST ACCOUNTING -available now 1635 25 821.86 1635 2) ACCOUNTS PAYABLE AND ACCOUNTS RECEIVABLE - available now 3) GENERAL LEDGER - orders now being accepted Each book sells for $15.00, and includes source listings in Wang BASIC, program and system documentation, and user's manual. Each is a complete package by itself, or all three may be implemented together to form a complete system with interdepen- dent files.

And if Wang BASIC won't work, or you don't know programming, or you'd rather not key in thousands of words of source code, take a look at the list of consultants who have adopted OEtA programs, converted them to run on many popular systems, and are waiting to hear from you. CP /M CBASIC: GOOD NEWS for CONSULTANTS, COMPUTER STORES AND SOFTWARE HOUSES

Osborne Et Associates is converting its business software from Wang BASIC - as it was originally published - to CP /M CBASIC, which runs on many floppy disk -based microcomputer systems. We will only sell the CP /M magnetic suKace tc consultants, computer stores and software houses. Osborne & Associates prefer to write and sell books, not customize the programs or answer the end user's questions. The disk for each book sells for $250.00. Once you buy the floppy disk you can copy it, resell it, change it or use it. We place no restriction on the magnetic surface; we copyright only the printed word in our books. CBASIC Payroll is available now. All three systems are scheduled to be available by the end of 1978; call or write for the exact availability of each system.

If you are an end user interested in the CBASIC programs, write or call us. We will put you in touch with your closest dealer.

DIGITAL GROUP: MITS 4.1 BASIC: MICROSOFT disk BASIC: Wang BASIC on floppy disk: John Musgrove William K. Haines Dan Kindred Richard Armour MUSGROVE ENGINEERING ANACOM GENERAL CORPORATION GNAT COMPUTERS, INC. ATLANTIC COMPUTER S CONSULTING 9547 Kindletree Drive 1160 E. Ash Avenue 7895 Convoy Court 1104 Sparrow Road Houston. TX 7.7040 Fullerton. CA 92631 San Diego. CA 92111 Chesapeake. VA 23325 17131466 -3486 1714) 992 -0223 17141560 -0433 18041764 -3412 DIGITAL GROUP zBO. Oasis BASIC: NORTH STAR: CP /M CBASIC: TRS -B0: Charles Finn Alan P. Hald OSBORNE S ASSOCIATES. INC Jim Smith THE SYSTEMS GROUP BYTE SHOP OF ARIZONA 630 Bancroft Way READY CORPORATION 2993 Bonng Ridge Drive 813 N. Scottsdale Road Berkeley, CA 94702 2502 Calle Madras Decatur. GA 30034 Tempe. AZ 85281 14151 548 -2805 Pleasanton. CA 94566 (4041289 -8969 (6021967 -1428 1415) 462 -4381 MICROPOLIS. PROCESSOR IBM 5110: TRS -80: TECH, NORTHSTAR: Mark Sherman Don French David Price DATA WORKS TANDY COMPUTERS 3901 Victoria Lane 35 E. Wacker Drive. Suite 1843 700 One Tandy Center Midlothian. VA 23113 Chicago. IL 60601 Fort Worth. TX 76102 13121726 -2572 1817) 390 -3011

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Becoming an OSA dealer S.F. BART residents add 6 I 2 ZIP PHONE School discounts O List of foreign distributors I am a dealer interested in Irurchas- I am an end user interested in run - O Other OSA publications ing CBASIC prugrams lorresale Please ning CBASIC programs. Please notify send description and order information me of the closest dealer for: Payment in advance must be enclosed for purchases for: of up to $70.00. Invoicing U.S. purchases over $70.00 CBASIC Payroll with Cost Accounting available upon approval of your account. All foreign CBASIC Accounts Payable /Receivable orders must be prepaid in U.S. dollars drawn on a US CBASIC General Ledger bank. 51001 Circle 292 on inquiry card:'

1 DIVIDEND DIVISOR (D3= I)

A6 A5 A4 A3 A2 Al AO D2 DI DO 4 Q

r-- -1 I 5 6 I 16 3 7 110 II

3 4 84 A3 B3 A2 82 AI BI A4 +5V /77 IC26 7483A 14 13 I ° 21 C4 E4 Z3 E2 EI CO

IC35 15 2 6 9 7404 13 10 6 3 14 II 5 2 L__J 48 38 28 IB 4A 3A 2A IA SELECT IC30 74157 12 15 4v STROBE 3Y 2Y IY 9 7 4

16 8 7 110 III 84 A3 83 A2 82 Al BI A4 +5V IC27 7483A 14 13 C4 EI CO 2 E4 E3 E2 IC32 15 2 6 9 7432 13 10 6 3 14 m 5 2 3 48 3B 28 IB 4A 3A 2A IA SELECT IC31 74157 12 4Y STROBE 3Y 2Y IY

9 7 4

16 3 4 8 7 110 III 84 A3 83 A2 82 Al BI A4 +5V IC28 7483A 14 13 C4 E4 CO 5 E3 E2 EI IC32 115 2 6 7432 13 10 6 14 II 5 12 6 48 38 28 IB 4A 3A 2A IA SELECT IC32 74157 12 4Y STROBE 3Y 2Y IY

9 7 4

16 3 4 8 7 110 84 A3 83 A2 82 Al BI A4 +5V IC29 74B3A 14 13 C4 E4 E3 E2 EI CO Q3 Q 9110 02 Q IC32 115 2 6 9 QUOTIENT 7432 13 10 6 3 14 m 5 2 01 Q 8 48 38 28 IB 4A 3A 2A IA 00 SELECT Q IC33 74157 STROBE 4Y 3Y 2Y 1 112 9 7 4 R3 Q R2 REMAINDER RI Q RO Q

Figure 4: Simple but slow clockless division circuit.

132 December 19780 BYTE Publications Inc The Microcomputer Bookstore 25 Route 101 West, Peterborough NH 03458 ßITS Best Sellers

-Getting Involved With Your Own Computer by Leslie Solomon and Stanley Veit answers the questions: "What can small computers do? Which is best for my purposes?" Whether your interest is business applications, word processing, education, security, etc., this lucid text will bring you in touch with an exciting new world destined to affect us all. $5.95. _The Thinking Computer: Mind Inside Matter by Bertram Raphael. Artificial intelligence, or Al, is the branch of computer science concerned with making computers "smarter." It is a growing, vital field that is, unfortunately, the subject of much popular misunderstanding. This book is a lucid introduction to Al that does much to overcome this misunderstanding. With a minimum of technical jargon, it discusses the capabilities of modern digital computers and how they are being used in contemporary Al research. It discusses the progress of AI, the goals, and the variety of current approaches to making the computer more intelligent. $6.95. Basic _BASIC Computer Games: Microcomputer Edition edited by David H Ahl. Here are 102 classic Computer computer games, every one in standard microcomputer BASIC; every one complete with large, legible listing, sample run and descriptive notes. All the classics are here: Super Star Trek (one Games of the most challenging versions anywhere), Football (two versions), Blackjack, Lunar Lander fiter Edition (three versions), Tic Tac Toe, Nim, Life and Horserace. This revision of 101 BASIC Computer Edited by David H. Ah1 Games is a real must, even if you own the original. $7.50. _BASIC and the Personal Computer by Thomas A Dwyer and Margot Critchfield. A fascinating b ook covering many areas of interest to the personal computer user. After giving an in -depth course in BASIC, which can be covered in 8 hours, the book discusses microcomputer hardware, graphics, word processing, sorting, simulation and data structures. This is an easy to read text that is useful for the beginner and informative for the advanced user. 438 pp. $12.95.

_Scientific and Engineering Problem Solving With The Computer by William Ralph Bennett Jr is o ne of the most exciting books we've seen in years. Besides teaching BASIC, this lively, lucid book presents a wealth of imaginative and unusual applications programs taken from many disciplines (A sample exercise: "Using the algorithm in the text with the pair -correlation matrix from Hamlet, compute the most probable diagram path which starts with the letter T "). The exercises run the gamut from random processes to the dynamics of motion, from entropy in language to the Water- gate problem. You'll discover BASIC applications in lasers and in the Fourier series and the law (!). In its diversity and elegant style, it ranks with Donald Knuth's works as a milestone in the art of computing. Hardcover $19.95.

_Computer Power and Human Reason by Joseph Weizenbaum. This book is one which should be p urchased or read for several reasons. If you're presently a programmer by trade or skill, you'll see a philosophy of computer use and abuse propounded. It's genuinely interesting, and definitely provocative if you reference the storm of letters, counter letters and counter counter letters which this book produced in the Association for Computing Machinery's SIGART newsletters during 1976. If you're a novice to the field, the tutorial and explanatory chapters of this book, which are aimed at the layperson, will serve as an excellent background source which is also eminently readable. This includes an excellent and low level explanation of what an algorithm is, and how computers go about executing effective algorithms. $5.95. COMPLITER Praised by many critics as the best books in their field, The Art of Computer Programming, POWER Volumes I, II and Ill, are part of a projected seven volume omnibus survey of computer science AND now being completed by Donald E Knuth. _Volume I, Fundamental Algorithms, begins with a thorough discussion of the mathematics used HUMAN in computer programming, followed by a treatment of information structures, stacks, arrays, REASON linked lists, dynamic storage allocation, and trees. 634 pp. $21.95. Volume II, Seminumerical Algorithms, is concerned with random numbers, statistical tests, JUDGMENT random sequences, as well as arithmetic (floating point and multiple precision), polynomials, and TO a rational arithmetic. 624 pp. $21.95. ge III deals with Searching and Sorting, and as the name implies, the emphasis is on algo- Volume

For your convenience in ordering, please use this page plus the order form on page 138. You may photocopy this page. DIAL YOUR CHARGE CARD ORDERS TOLL -FREE 1- 800 -258-5477.

Circle 35 on inquiry card. BYTE December 1978 133 DIVISOR (D7=1) pU00D6 D5 D4 D3 D2 DI DO

2 IC24 7432 3 2 13 - I GATES OR MEMORY J GATES OR MEMORY 1C23 LOOKUP OF TABLE I LOOKUP OF TABLE I 7427 I \a/ IC25 JI 17 16 15 14 I3 12 II IO J4 J3 J2 JI JO 7486 12 L-3--- (I8.1)

B4 B3 B2 BI BO A3 A2 Al AO

4 BY 5 MULTIPLIER (SEE FIGURE 3)

P7 P6 P5 P4 P3

10 /77 I 116 3 14 8 I7 10 III 16 3 4 8 7 A4 B4 A3 B3 A2 B2 Al BI A4 B4 A3 B3 A2 B2 Al BI IC21 7483A IC22 7483A 13 14 13 CO C4 CO 14 i3 E2 £I 14 13 i2 î1

15 2 6 19 15 2 6 19

DIVIDEND

A7 A6 A5 A4 A3 A2 Al AO

V V V V V V Q B7 B6 B5 B4 B3 B2 BI BO AO Al A2

A3 8 BY 8 MULTIPLIER A4 (SEE CAPTION) AS A6 A7 PI5 P14 P13 P12 PII PIO P9 P8 P7

16 3 0 8 7 10 II 16 3 4 8 7 10 III B4 A3 B3 A2 B2 AI BI B4 A3 B3 A2 B2 Al BI A4 A4 IC19 7483A IC20 7483A 14 13 14 C4 CO C4 14 CO 14 E3 E2 1 î3 E2 iI

15 6 9 15 2 6 9 0 0 0 Q7 Q6 05 04 03 02 01 Q0 ROUND

QUOTIENT

134 December 1978 © BYTE Publications Inc is positive, the multiplexer transmits this Table 1: List of l and / difference. The quotient bits are the same values for 8 bit divider bits that set the multiplexers. This method is circuit of figure 5. straightforward and provides a remainder, but has the disadvantage of being relatively slow. A more elegant clockless divider makes UPPER D J use of the relation 1 /(1 -r) z 1 +r, provided the absolute value of r is much less than 1. d7d6d5d4d3 1413121110 The error in this estimate is r2, as can be 000 111100010 1100 seen by multiplying each side of the approxi- 001 111000111 010 1001 mate equality by (1 -r). Suppose an 8 bit 110101111 0111 0 1 1 110011010 0100 is be dividend (A = a7a6a5a4a3a2a1 a0) to 1 0 0 110000110 0011 divided by an 8 bit left- adjusted divisor 1 0 1 101110100 0001 1 1 0 101100100 1111 (D = d7d6d5d4d3d2d1 do) to yield an 8 bit 111 101010101 1110 integer quotient Q. Let: 0 0 0 101001000 1101 0 0 1 100111011 1100 0 1 0 100101111 1011 r = (23-d2d1 d0)/[23 (d7d6d5d4d3+1) ] 0 1 1 100100101 1010 1 0 0 100011010 1010 This means that: 1 0 1 100010001 1001 110 100001000 1001 111 100000000 1000 D = (d7d6d5d4d3 +1)(23)(1 -r) Q = 27 (A) /[(d7d6d5d4d3 +1)(23)(1 -r)], Q^ 24(A)(1 +r) /(d7d6d5d4d3 +1).

Since d7 equals 1, r is less than 23/(23 x 24) or 2 -4, and r2 is less than 2 -8. Q in this approximation is accurate to at least eight Table 2: Power connec- bits. Let: tions for integrated cir-

cuits used in figures 1 thru I = 212 /(d7d6d5d4d3 +1) 5.

and Power Wiring Table J = 212/(d7d6d5d4d3 +1)2 Number Type +5 V Gnd

IC1 74284 16 8 each rounded to the nearest integer. Then IC2 74285 16 8 Q is approximately equal to 2-8(A) [ I+ IC3 7483A 5 12 7483A 5 12 (23- d2d1d0)(2- 3)(J)] and the division IC4 IC5 7483A 5 12 problem has been reduced to addition and IC6 7408 14 7 7408 14 7 multiplication once I, J and (23- d2d1d0) IC7 7408 14 7 have been determined. IC8 IC9 7408 14 7 This last quantity is easily derived from IC10 7483A 5 12 5 12 four simple gates, as illustrated in the com- IC11 7483A IC12 7483A 5 12 plete divider of figure 5. The quantities I and IC13 7483A 5 12 7 J are listed in table 1 for all possible values IC14 7402 14 7402 14 7 of d7d6d5d4d3. These are found to 9 bit IC15 IC16 7402 14 7 and 5 bit accuracy, respectively, to insure IC17 7402 14 7 8 bit accuracy in Q after the intermediate IC18 7402 14 7 IC19 7483A 5 12 IC20 7483A 5 12 IC21 7483A 5 12 Figure 5: Faster 8 bit clockless divider. The IC22 7483A 5 12 IC23 7427 14 7 4 by 5 multiplier is the circuit of figure 3. IC24 7432 14 7 The l and / values are obtained from a set of IC25 7486 14 7 7483A 5 12 gates or a lookup table. The results being IC26 IC27 7483A 5 12 looked for are the values given in table 1. IC28 7483A 5 12 The 8 by 8 multiplier is the only device not IC29 7483A 5 12 IC30 74157 16 8 previously discussed. The multiplier is com- IC31 74157 16 8 posed of bit slices; the theory behind the IC32 74157 16 8 74157 16 8 multiplication circuits can be found in the IC33 IC34 7432 14 7 TTL Data Book for Design Engineers, pub- IC35 7404 14 7 lished by Texas Instruments Inc. The device IC36 7404 14 7 IC37 7404 14 7 number is SN54LS275, found Jn page 7 -391 of the 1976 edition.

December 1978 © BYTE Publications Inc 135 ucts and quotients are obtained through steps. I and J may be determined for a given divisor by a lookup process or by a suitable time -consuming subroutines. Computer arrangement of gates. Of course, the entire generated music or animated video displays division may be performed by looking up may not permit sufficient computation time. the inverse of the 8 bit divisor and then mul- Such real time outputs would be feasible if tiplying, but the method described here uses the fast circuits described here were incor- one eighth the memory space and only porated into an external arithmetic unit and slightly more circuitry. accessed through the input /output (IO) This process uses the inverse of a small ports of the microcomputer. Then a division number to find the inverse of a larger num- would be performed by the following: ber, and so suggests a procedure for handling Output the divisor to the external the division of numbers of arbitrary size. arithmetic unit divider. Such multiple -precision calculations could Output the dividend to the external be performed by expanding the kind of arithmetic unit divider. hardware described here, or by an iterative Input the quotient from the external software routine. Remainders are not arithmetic unit divider. available this and must directly from circuit, Input the remainder (if desired) from be obtained by subtracting the product of the arithmetic unit divider. the quotient and divisor from the dividend. The requirement that the divisor be left - Holding registers are required for the divi- adjusted is something of a nuisance; dividers sor and dividend. If 8 bit arithmetic is used, generally need a restriction of this sort to the entire calculation can be performed keep the calculation in range of the hard- easily in the time taken by the input and ware capability. Methods exist to make this output instructions. adjustment and the subsequent adjustment required in the quotient without the use of clock pulses. These cumbersome circuits will Editor's Note: not be described here. These circuits are theoretical. They Is any of this useful to the small systems owner? Most microprocessors do not have have been designed but not implemented multiplication or division instructions. Prod- by the author.... RGAC. The Texar Inrtrumentr THE DATA BOOK SERIES Microcomputer LibrarL Power Semiconductor Data Book 770 pp. Hardcover, $7.50. When you build a project, you need informa- Semiconductor Memory Data Book tion. All you find in the advertisements for parts are mysterious numbers...hardly the sort 272 pp. $2.95. of information which can be used to design a TTL Data Book, 2nd edition custom logic circuit. Data books are the essen- 828 pp. Hardcover, $4.95. tial references which allow us to manage the Supplement to the TTL Data Book, 2nd edition hundreds of thousands of different devices that 56 pp. $1.25. make up the electronic equipment we use. The Transistor and Diode Data Book Texas Instruments data book series is foremost 1199 pp. Hardcover, $8.50. in the field, containing a wealth of information Optoelectronics Data Book, 5th edition on the devices which TI manufactures. 366 pp. $3.50. Bipolar Microcomputer Components Data Book OTHER BOOKS FROM TI 247 pp. $2.95. Linear Control Circuits Data Book Fingertip Math 368 pp. $2.95. For your convenience in 264 pp. $2.95. Interface Circuits Data Book ordering, please use this Software Design for Microprocessors ad plus the order form 592 pp. $4.75. 390 pp. Hardcover, $12.95. on page 138. You may photocopy this page. The Great International Math on Keys Book 200 pp. $4.95. DIAL YOUR BANK Understanding Solid State Electronics, 3rd edition CARD ORDERS TOLL 242 pp. $3.95. FREE (800) 258 -5477. Designing With TTL Integrated Circuits ßUTSM1nc 322 pp. Hardcover, $31.50. POB 428, 25 Route 101 West, Peterborough NH 03458

136 December 1978 © BYTE Publications Inc Circle 35 on inquiry card. Everything you've ever wpted to know pbout microcomputers in ONE co lete book Over 400 pages. Full 81/2" x 11" size. for only $10.95

The ultimate book about microcomputers. Written by experts ... SCELBI and BYTE. Over 400 pages. A collector's item, featuring The Basics from the first 16 issues of BYTE and SCELBI's classic library of books. Your microcomputer almt% bookshelf is incomplete without this priceless edition.

you can't buy information How does a microcomputer do All about building a micro- organized like this any- it? Lots of "how to" theory. In- computer system. Over 12 com- where. This is the book troducing you to microcomputer plete construction articles. Flip - that everyone who is into micro- operation. 6800, 6502, Z80 CPU flops. LED devices. Recycling computers needs for reference, chip capabilities. RAM and ROM used ICs. Modular construction. for ideas, for clues to problem memories. Addressing methods. Making your own p.c. boards. solving. It is a truly authorita Prototype board construction. tive text, featuring easy -to-read, Make your own logic probes. easy -to- understand articles by THE Construction plans for 6800 and more than 50 recognized pro- SCElE11BVTE Z80 computers. Building plans fessional authors, who know and for I /Os - TV and CRT displays, love microcomputers from the PNIIiIEN cassette interfaces, etc. Mathe- matics functions. ROM program- ground up. Logical and com- Over 400 pages. Selected articles plete, it features many glos- from BYTE and SCELBI books. mer. Plus much, much more. saries, and is illuminated with Profusely illustrated. Many How to program a micro- profuse illustrations and photo- photographs. $10.95, plus $1 computer. Programming for the graphs. shipping and handling. beginner. Assembling programs The Scelbi /BYTE Primer is by hand. Monitoring programs. divided into four logical sec- How to control peripherals. Number conversions. Game of tions, that take you from point Transmission of information to Hexpawn. Design your own as- "0" through building and pro- and from computers. Magnetic sembler. Lots more. gramming your own computer... recording devices for bulk stor- And that's only the beginning! step -by- step -by -step. age. Analog to digital conver- Others have spent millions ac- What can you do with a micro- sion. How a computer can talk. quiring the type of microcom- computer? Checkbook balanc- Other I/O techniques. And more. puter information found within ing. Recipe converting and food the 400 pages of The Scelbi/ inventory. Heating and air condi- Order your copy today! BYTE Primer. But, it costs you SCELBI COMPUTER tioning control. Home and busi- CONSULTING INC. BITS only $10.95, plus $1 for postage ness security and management. Post Office Box 133 PP STN 25 Route 101 West and handling, complete! You Dept. B P.O. Box 428 know the of Scelbi and Playing the ponies. Analysis of Milford, CT 06460 Peterborough, NH 03458 quality the stock market. Maintaining 1.800- 2585477 BYTE. This is your assurance of massive data banks. Self- instruc- Prices shown for North American customers. excellence throughout this MUST Master Charge. Postal and bank Money tion. Toys and games. Small Orders preferred. Personal checks delay text. Order your copy today! And, business accounting and inven- shipping up to 4 weeks. Pricing, specifica- get one for a friend! tions, availability subject to change without tory. And lots, lots more. notice.

BYTE December 1978 137 Wrap me Up and Take me Homme

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138 BYTE December 1978 _Periodical Guide for Computerists, January- December 1977, Microcomputer Primer by Mitchell Waite and Michael Pardee. by E. Berg Publications. This is a comprehensive index of all thear- Here's a microprocessor tutorial for readers having some electronics ticles, book reviews, editorials, letters, record reviews, and miscella- background. Microcomputer Primer concentrates on the hardware neous small inserts and notes from the top 25 magazines in the field. of microcomputers (although there are sections dealing with soft- Several thousand articles are grouped into over 60 subject categories ware) with chapters on basic computer concepts, hardware, pro- that are listed alphabetically for easy reference. At the back is an au- gramming, memories, and number systems. A full complement of thor index, including the major areas of their expertise. An indispen- photos and schematics accompanies the text. 224 pp. $7.95. sable guide for anyone in the fields of personal computing, amateur radio, and electronics. 72 pp. $5.00. _Programming a Microcomputer: 6502. This informal, well -written book may be just what you need to enter the world of micro- _Robots on Your Doorstep by Nels Winkless and Iben computers. Caxton C. Foster uses the 6502 as a basis for discussing Browning. "This book will amaze you, frighten you, nauseate you, the techniques of writing programs. The chapters include simple, excite you...it will probably make you think about things you have practical example programs for creating a Morse Code oscillator, never contemplated before," states the introduction to this clever combination lock, tune player, digital clock, and more. The empha- and well -written account of robots: past, present, and future. Intelli- sis is on clarity, and the many illustrations and flowcharts help get gence, artificial intelligence, brain structure and simulation, and the author's points across. 231 pp. $9.95. characteristics of robots are only a few of the areas explored. One chapter is devoted to the personal computer revolution and how it has brought robots into the amateur's workshop. 179 pp. $6.95. _Programmable Calculators by Charles J. Sippl and Roger J. Sippl. This large (526 pages) book is an exhaustive survey of the programmable calculator field covering its history and present _Programming in PASCAL by Peter Grogono. This book is an status. Chapters deal with the basic calculator, advanced hand- excellent introduction to one of the fastest growing programming held products, RPN (Reverse Polish Notation) versus algebraic languages today. The text is arranged as a tutorial containing both notation, desktop calculators, and programming the program- examples and exercises to increase reader proficiency in PASCAL. mable calculator. Examples and illustrations abound in this use- Besides sections on procedures and files, there is a chapter on dy- ful reference work. $14.95. namic data structures such as trees and lin ked lists. These concepts are put to use in an example bus service simulation. Other examples range from the Tower of Hanoi problem to circumscribing a circle Here are two big packages of fascinating information and practi- about a triangle. Programming in PASCAL is sure to hold the read- cal guidelines from the symposiums held at the 1977 and 1978 West er's interest. 359 pp. $9.95. Coast Computer Faires. _The First West Coast Computer Faire Conference Proceedings, edited by Jim C. Warren, Jr., contains 336 pages covering such top- -Z80 Programming for Logic Design by Adam Osborne, Jerry ics as: tutorials for the computer novice, human aspects of system Kane, Russell Rector, and Susanna Jacobson. Here's the book we've design, robots (including the text of a talk by science fiction writer all been waiting for! It's third in the series of Osborne's program- Fred Pohl), computers for the physically disabled, education, elec- ming for logic design books (the 8080 and 6800 books). Written for tronic mail, music with computers, hardware, software -the list goes both programmers and logic designers, it explains how an assembly on. $12.00. language program can replace non -programmable logic devices -with _The Second West Coast Computer Faire Conference Proceedings, direct reference to the Z80 microcomputer. 352 pp. $8.50. edited by Jim C. Warren, Jr., is 505 pages and covers many of the above topics plus others such as: computers for the visually handi- _8080A/8085 Assembly Language Programming by Lance A. capped, exotic computer games, high level design for microproces- Leventhal. This book provides an introduction to assembly language sors, computer articles for business and crafts, homebrewed equip- programming for the 8080A and the 8085 processors. Included are ment, and speech input and output. You can't miss for only $13.00. sections on the instruction sets for the two processors, assemblers, simple program examples, code conversion, tables and lists, subroutines, 10, interrupts, program design, and debugging. Many examples -Up your Own Organization! by Donald M. Dible. A great hand- and illustrations are included to cover critical points. 467 pp. $8.50. book on how to start and finance a new business, this is the most comprehensive reference we've seen on the subject. For the programmer- consultant or the basement homebrewer- turned -entrepre- Profit from your Personal Ted G. _How to Computer by Lewis. neur, this is your book. It is recommended in the Bank of America If you have wanted to use your personal computer in a profitable Small Business Reporter and Changing Times magazines. 372 pp. manner, and you feel you need some help planning programming Available for $14.95 in hardcover. techniques for common business applications, this book is for you. Enjoyable and readable, it contains suggestions for accounting, payroll handling, inventory management, and sorting mailing lists. Many _Fundamentals of Recordkeeping and Finance for the Small terms and notations are explained. Sample programs in BASIC, the Business by Robert C. Ragan, CPA, and Jack Zwick, Ph.D. Once use of blueprints to design program structure, and a full glossary of you have your organization or business up and running, records terms are a few of this book's special features. 191 pp. $7.95. must be kept. What should I keep, and how do I record them? This book on fundamentals will give you a helpful start. Section One _SARGON by D. and K. Spracklen. A complete computer chess deals with maintaining records, protecting assets, and providing a ba- program that won the 1978 West Coast Computer Faire Chess sis for planning. Section Two provides a starting point for owner - Tournament. Highly praised in the 9/78 issue of Personal Com- managers who want to sharpen their financial management skills. puting. Available early November. 120 pp. $14.95. (No photo) 196 pp. Only $10.00 in hardcover. ¡ Dealer inquiries invited. I1 I C ITS (nooks to erase the impossible

Circle 35 on inquiry card. BY Tr December 1978 139 Creating a Chess Player Part 3: Larry R Atkin Health Information Services 542 Michigan Av Evanston IL 60202

Chess 0.5 (continued) Peter W Frey Dept of Psychology Northwestern University Evanston IL 60201 Listing 1: The second half of Chess 0.5, written in Pascal. This portion of the program covers evaluation of terminal nodes, the look -ahead procedure and user commands (listing 1 continued on page 146).

PROCEDURE EVALUA; 1 EVALUATE CURRENT POSITION 1 This month we conclude the listing VAR INTV I TV; I. SCORE 1 and commentary of Chess 0.5 begun last issue. The program was written by

FUNCTION EVKING I. EVALUATE KING 1 Larry Atkin, who is coauthor with David (AIRS; I. KING BIT BOARO 1 MIRS)ITV; 0, FRIENDLY PAWN BIT BOARO 1 Slate of the world championship chess

VAR program, Chess 4.6. The program is INTS I TS; 0 SCRATCH 1 readily adaptable to personal computers INRS I RS1 0 SCRATCH 1 TV; INTV I I. SCRATCH 1 having Pascal systems such as the UCSD BEGIN Pascal project software. Part 4 concludes ANORSI INRS. A, CONNRII IF NULRSIINRSI THEN I. KING NOT IN CORNER 1 the series with a discussion of chess INTV I. O ELSE strategy and tactics. INTV 1. FKSANQ; 1 KING SAFELY IN CORNER )

INRS 1. A; IF NRTTSIINRS,INTSI THEN BEGIN ANORS(INRS,ATKFR(INTS)hS1; 1 FINO PAWNS NEXT TO KING 1 INTV 1. INTV CNTRS(INRSIFKPSHOI Evaluating 0 CREDIT EACH CLOSE PAWN 1 Terminal Positions ENO;

EVKING I= INTV; ( RETURN KING SCORE 1 Another important aspect of any chess END; 1 EVKING 1 program is the function which provides a static evaluation of terminal positions in the FUNCTION EVHOBL 0 EVALUATE NOBILITY 1 (A,BITPI ITV: 0, PIECE TYPES TO EVALUATE 1 look -ahead tree. In the present program, this

VAR routine also doubles as a preliminary scoring INRS I RSI SCRATCH 1 0 function for sorting moves at the ply, at INTS I TS; ( SCRATCH 1 first INTV I TV; 0 SCRATCH 1 the beginning of the look -ahead search. BEGIN Since the evaluation function is used repe- IORRSIINRS,TPLOCIAI.TPLOCIBII; 0 MERGE PIECE TYPES 1 INTV I= Xl 0 INITIALIZE COUNT 1 titively in the search, efficiency demands WHILE NXTTS(INRS,INTS1 DO 0 COUNT ATTACKS 1 INTV 1= INTV CNTRSIATKFRIINTSII; that it be carefully engineered. We have left EVMDBL 1= INTV; ( RETURN TOTAL ATTACKS 1 END; 1 EVMOBL 1 this task as an exercise for the reader. Our function presently includes only a few basic

FUNCTION EVPAWN 0 EVALUATE PAWNS 1 essentials. (AIRS; 0 LOCATION OF PAWNS 1 The most important feature is material. BITE; 0 PAWN FORWARD DIRECTION 1 CITRI ITV; 0 PAWN HOME RANK ) We employ essentially the same function for VAR this that is used by Chess 4.5. A trade -down INRS I RS1 1 SCRATCH 1 IHRS I RS1 1 SCRATCH 1 bonus is also incorporated, ie: trade pieces INTS I TS; 1 SCRATCH 1 INTV I TV; ( SCRATCH 1 but not pawns when ahead in material. A BEGIN second feature which is considered is piece SFTRS(INRS.A.S11; ANORSIINRS.INRS.AI; 0 BIT SET FOR SIGE BY SIOE 1 mobility. The mobility of Knights and INTV I. CNTRSIINRS)FPFLNRI 0 SCORE PHALANX 1 Bishops is weighted more heavily than that SFTRSIINRS.A.B111 for Rooks and Queens. Special credit is ANORSIINRSINRS,A1; I. BIT SET FOR PAWN DEFENSE 1 INTV 1. INTV CNTRSIINRSIFPCONN; 0 CREDIT CONNECTED PAWNS 1 given to a King which is located in one of SFTRSIINRS,A.021; the four corner squares in each corner of ANORSIINRS.INRS,A1; INTV I. INTV CNTRSIINRSIFPCONN; 0 AND OTHER CONNECTED PAWNS 1 the board, ie: 16 squares total. This encour- SFTRSIINRS,A,01; 1 MOVE FORWARD 1 ages early castling. Pawn structure is con- NOTRS(INRS.TPLOCINTII; 1. OCCUPIED SQUARES 1 ANORSIINRS,INRS,IHRS1; 0 BLOCKED PAWNS ) sidered by providing a bonus for advancing INTV I. INTV - CNTRS(INRS)FPBLOK: 0, PENALIZE BLOCKED PAWNS 1 the pawns in the four center files, for hav- CPYRSIINRS,A1; ing a pawn near the King, and having a WHILE NXTTSIINRS,INTSI 00 0 FOR EACH PAWN 1 for INTV I. INTV H IABSIOROICI- ORDIXTSR(INTS 1111FPADCR( XTSF( INTS 111 pawn adjacent to or defended by another I. CREDIT PAWN AOVANCEHENT 1 pawn. This indirectly penalizes isolated or EVPAWN 1. INTV; ( RETURN PAWN SCORE 1 ENO; I. EVPAWN 1 backward pawns. There is a direct penalty

140 December 1978 © BYTE Publications Inc TRS -80 USERS ; if the square in front of a pawn is occupied. The position of the Rooks is considered by We've got the stuff providing a bonus for placing a Rook on the seventh rank and for attacking another Rook of the same color (ie: doubled Rooks). The that makes it tick ! executive routine for these assessments is EVALU8.

The Look -Ahead Procedure

The look -ahead procedure is controlled by an executive routine called SEARCH. SoftSa Several subprocedures are also defined which handle specific tasks. NEWBST Your home computer is only as useful keeps track of the move which is currently as what you put into it, and every thought to be best, and dynamically re- month SoftSidetm publishes original orders the moves at the first ply level each debugged software that's bound to time a new best -move is selected. MINMAX delight, entertain, educate and serve determines whether the move under con- - free for the transcription in a form both you and your computer can sideration will produce an a -ß cutoff. understand. SCOREM is called into action when the Subscribe today, and ENTER a whole program can find no legal moves at a node. new world of software for personal It determines whether the position should use ! ham be scored as a checkmate or as a stalemate. Se radio children's quizzes t%1 SELECT is responsible for move ordering at ihOenchobbies football pe obt3 e5 4ryrbbagt each node. It determines whether there are mu , ße°c any more moves to be searched and if so, ,eittnword proCeshúSneseeas makes sure that they are generated in the ab'e Aáucation bO. correct order (ie: captures, killers, castling moves, and then the remaining moves). SEARCH incorporates a number of important features which make the look -ahead search more efficient. These include staged Bored with move generation, preliminary ordering "zap the Klingons" scores, setting a narrow a -ß window at the programming fare? beginning of the search, conducting the The TRS -80 Software Exchange offers an alternative. At the back of search in an iterative fashion, and dynami- each issue of SoftSidetm, The TRS -80 cally recording moves at the first ply as Software Exchange Market Basket the search proceeds. Because of these fea- lists programs that serve a variety of tures, the full -width search takes a long time interests. Are you a pilot ? How about instead of taking forever. a computerized flight plan ? If you're interested in using your TRS -80 for User Commands business, we've got programs to handle accounting, payroll, inventory For the user's convenience, the program management - even a cash register should be able to respond to a few simple program! Whether you're interested commands. Inputs to the program are pro- in statistical analysis, or Tarot cards, or even real estate, you're sure to cessed by a lengthy routine, READER, find something in The TRS -80 which has many component subprocedures. Software Exchange Market Basket ! The translation of the input string is handled Where can you get it? by a group of routines: RDRERR, RDRGNT, Only in SoftSide ! RDRSFT, RDRCMP, RDLINE, RDRMOV and RDRNUM. Each of the commands is executed by a separate routine. When the human player wishes to terminate the game before it has reached its con- l clusion (eg: when he is hopelessly lost and 1 Year (12 issues) for $15.00 money does not want to stay around to be crushed), Send check or order to: he can simply type an END command and visa SoftSide Subscriptions the ENDCMD routine will terminate the PO Box 68 Milford, NH 03055 [ program. If the user simply wishes to start a VISA /Master Charge orders accepted. new game, he can type INIT and the Send signature, account #, exp. date of INICMD routine will set up for a new game. card and interbank # (M /C only) along with your order.

Circle 326 on inquiry card. December 1978 © BYTE Publications Inc 141 Circle 353 on inquiry card.

If the user would like to set up a specific CBASIC Is Better position from the previous game or some other game, he can call the BOACMD rou- Take CBASIC -the best Business BASIC. Make it faster, easier to use, tine, which will set up any position he de- and more flexible, and you have sires. To use this instruction, the pieces are designated in the standard way (eg: K, Q, R, B, N and P) and the colors are designated CBASIC-2 by L for light and D for dark. The board is described by starting at the lower lefthand New features that enhance CBASIC's value as the best corner and listing, row by row, the 64 buy in Business BASIC: CHAINING to pass control from program to program; squares. Numbers are used to represent con- INTEGER VARIABLES allow fast computation in 16 -bit binary secutive empty squares. The command to arithmetic: MULTIPLE LINE FUNCTIONS easier, more allow set up the position after 1. P -K4, P -K4, 2. structured coding: XREF produces a cross -reference dictionary of variables; SAVEMEM reserves memory space N -KB3, N -QB3 is: BOARD, LRNBQKB1 and loads subroutines; SADD% returns absolute address of RP PPP1PPP5N24P34DP33N4PPPP1PPPRIB strings; CONSTAT% reports console status; UCASE$ converts QKBNR. a string to upper case; COMMAND$ returns contents of command line; plus CONCHAR %, %EJECT, FILE If the human player is lazy or simply BUFFERING, %PAGE, and more. wishes to test the program, he or she can Special Introductory Price: $89.95 type GO and the machine will select a SSG CBASIC version one move. By repeatedly typing GO the user owners can update for only: $49.95 can sit back and watch the machine play (send registration # when ordering) against itself. The routine that handles Other vendors sell CBASIC. this is GONCMD. To specify a value for But how many back their customers when up selected program parameter variables, the software is updated? We do. For information, or to order, contact player can use LETCMD. For example, the amount of time the machine spends calcu- ltructured !totem/ Group lating a move can be controlled by specify- I NC OR O PA ¡E Li ing a the number nodes to be 5208 CLAREMONT AVENUE limit for of OAKLAND, CALIFORNIA 94618 searched. The command LET FNODEL = (415) 5471567 1000 will cause the machine to set a target value of 1000 for the number of nodes to be searched. In this case it will not start another iteration if it has already searched 1000 nodes. If the user is confused about GRAPHICS STOCK ANALYSIS the current board configuration, the com- NAVIGATION ASTRONOMY mand PRINT will activate PRICMD which NUMBER THEORY GAMES calls PRINTB for a representation (8 by 8 array) of the board. For diagnostic purposes the user can also ask for other information. The routine PAMCMD is activated by PB THE and provides an 8 by 8 attack map for each RECREATIONAL MI of the 64 squares. The routine POPCMD is PROGRAMMER activated by PO and gives information concerning the side to move (White or Black), the en passant status after the last move, the Users of computers and programmable calculators present castle status and the move number. enjoy this magazine! The articles are of If the user types PM, the routine PMVCMD interest to hobbyists and professionals. The programs are accompanied by explanations will provide a list of all moves which are written in clear, logical language. Our legal for the side to move in the current posi- authors are people who own and use machines tion. The command PL activates PLECMD like yours ! which prints the value of a designated variable; for example, the user can determine "The Recreational Programmer" is issued bimonthly. It is available by subscription only the present limit for the number of nodes to for twelve dollars per year (domestic), or be searched by typing PL FNODEL. fifteen dollars per year ( foreign ). The user also has control over several Subscriptions and articles may be sent to: switches. He can ask the machine to repeat THE RECREATIONAL PROGRAMMER (echo) each entry, to pause after 20 lines of BOX 2571 output, and to reply automatically each KALAMAZOO MICHIGAN 49003 time the opponent enters a move. These switches are set by the switch commands (eg: SW EC OFF), and are processed by SWICMD. If the user wishes to manually EXCELLENT CHOICE ! alter one or more of the status conditions

142 December 1978© BYTE Publications Inc Circle 307 on inquiry card. TM

° Shraye r I the electric oencil1978 Michael

The Electric Pencil II is a Character Oriented As text is typed in and the end of a screen Word Processing System. This means that text is line is reached, a partially completed word is entered as a string of continuous characters and shifted to the beginning of the following line. is manipulated as such. This allows the user Whenever text is inserted or deleted, existing enormous freedom and ease in the movement and text is pushed down or pulled up in a wrap handling of text. Since line endings are never around fashion. Everything appears on the video delineated, any number of characters, words, display screen as it occurs which eliminates any lines or paragraphs may be inserted or deleted guesswork. Text may be reviewed at will by anywhere in the text. The entirety of the text variable speed scrolling both in the forward and shifts and opens up or closes as needed in full reverse directions. By using the search or the view of the user. The typing of carriage returns search and replace function, any string of as well as word hyphenation is not required characters may be located and /or replaced with since lines of text are formatted automatically. any other string of characters as desired.

When text is printed, The Electric Pencil II automatically inserts carriage returns where they are needed. Numerous combinations of line length, page length, line spacing and page spacing allow for any form to be handled. Character spacing, BOLD FACE, multicolumn as well as bidirectional printing are included in the Diablo versions. Right justification gives right -hand margins that are even. Pages may be numbered as well as titled. This entire page (excepting the large titles and logo) was printed by the Diablo version of The Electric Pencil II in one pass.

NEW FEATURES: * CP /M, IMDOS and HELIOS Compatible * Supports Now on CP/M Four Disk Drives * Dynamic Print Formatting * DIABLO as well as NEC printer packages * Multicolumn Printing * Print Value Chaining * The Electric Pencil II Page -at -a -time Scrolling * New Bidirectional Multispeed Scrolling is also compatible with Controls * New Subsystem with Print Value Scoreboard * Automatic Word Imsai's IMDOS. HELIOS and Record Number Tally * Cassette backup for additional storage * Full versions SSH and DSH are Margin Control * End -of -Page Control * Non -Printing Text Commenting * now ready. The NEC print Line and Paragraph Indentation * Centering * Underlining * BOLD FACE * package is now available.

A utility program that W I D E S C R E E N V I D E O ! ! ! converts PENCIL to CP /M to PENCIL files is ready. Available to Imsai VIO video users for a huge 80x24 character screen. "CONVERT" is only $35.00. These versions put almost twice as many characters on the screen HH! HAVE WE GOT A VERSION FOR YOU ?

The Electric Pencil II operates with any 8080 /Z80 based microcomputer that supports a CP /M disk system and uses a Imsai VIO, Processor Technology VDM -1, Polymorphic VTI, Solid State Music VB -1B or any similar memory mapped video interface. REX versions now available. Specify when using CP /M that has been modified for Micropolis or North Star disk systems as follows: For North Star add suffix A to version number, for Micropolis add suffix B to version number, e.g. SS -IIA, DV -IIB.

Vers Video Printer Price

SS -II SOL TTY or similar $225. SP -II VTI TTY or similar $225. MICHAEL SHRAYER SOFTWARE, INC. SV -II VDM TTY or similar $225. 1253 Vista Superba Drive SR -II REX TTY or similar $250. m Glendale, CA 91205 SI -II VIO TTY or similar $250. (213) 956 -1593 DS -II SOL Diablo 1610/20 $275. SS DP -II VTI Diablo 1610/20 $275. DV -II VDM Diablo 1610/20 $275. DR -II REX Diablo 1610/20 $300. DI -II VIO Diablo 1610/20 $300. Electric Pencil I is still available for non CP /M users: NS -II SOL NEC Spinwriter $275. NP -II VTI NEC Spinwriter $275. Vers Video Printer Cassette Disk Drive Price NV -II VDM NEC Spinwriter $275. NR -II REX NEC Spinwriter $300. SS SOL TTY or similar CUTS $100. NI -II VIO NEC Spinwriter $300. SP VTI TTY or similar Tarbell $100. SSH SOL Helios /TTY $250. SV VDM TTY or similar Tarbell - -- $100. DSH SOL Helios /Diablo $300. SSN SOL TTY or similar CUTS North Star $125. SPN VTI TTY or similar Tarbell North Star $125. UPGRADING POLICY: Any version of SVN VDM TTY or similar Tarbell North Star $125. The Electric Pencil may be upgraded DS SOL Diablo 1610/20 CUTS - -- $150. at any time by simply returning the DP VTI Diablo 1610/20 Tarbell $150. original disk or cassette and the DV VDM Diablo 1610/20 Tarbell - -- $150. price difference between versions DSN SOL Diablo 1610/20 CUTS North Star $175. plus $15.00 to MSS. Accept only DPN VTI Diablo 1610/20 Tarbell North Star $175. original media at time of purchase. DVN VDM Diablo 1610/20 Tarbell North Star $175. Demand a demo from your dealer ! Circle 319 on inquiry card. BYTE December 1978 143 (eg: side to move, move number, en passant, places the Rook on the Queen Bishop file castling), this can be done by activating can be designated as R -B1, R -QB1, R /1 -B1,

STACMD. R/1 QB1, R /R1 -B1, or R /R1 -QB1. I t is important that the program recognize that each Notes on Notation of these character strings represents the same move. How is this done? The program also processes standard One way is to have the machine generate chess notation. This is not strictly necessary. a list of all legal moves and then compare Many programs use their own convention for each of these with the move entered by the entering and reporting moves. A common player. If his move matches one on the list, procedure is to denote the squares using a that move is noted. The rest of the list is number (1 through 8) for each row and a then checked and if no more matches are letter (A through H) for each column. A found, the noted move is assumed to be the move is defined by listing the present square correct one. If no match is found, the ma- of the piece and then the destination square. chine prints "illegal move." If a second For example, the common opening move, match is found (eg: P -B3 matches both P -K4, would be E2E4. Moving the White P -KB3 and P -QB3), the machine prints Knight on the kingside from its original "ambiguous move." The process of trans- square to KB3 would be G1 F3. This con- lating the opponent's move into machine vention works nicely but it forces an ex- compatible form and checking its legality perienced chess player to learn a new sys- or ambiguity is done by YRMOVE. The tem. Most would prefer standard chess process of translating the machine's move notation. into standard notation is handled by Because there are multiple ways to ex- MYMOVE. Both of these procedures call press the same move in standard notation, MINENG, which is responsible for con- the translation routine needs to be fairly structing the appropriating character strings. sophisticated. Consider a position in which the White Queen's Rook is on its Final Thoughts original square and the neighboring Knight and Bishop have been moved. A move which This completes our listing of our demonstration chess program. Despite the program's length, there are many desirable features which have been omitted. The reader with an interest in chess and programming LSI-11 TIME should use this listing as a starting point for developing a program. The time required for move calculation can be reduced by writing machine dependent code for some tt:... i, '., of the frequently used routines. There are ;,, l'1, '4 't4 : also features which can be added to improve i. the level of play. TI'- ,:r TT¡ 1 JI 14u T , i6 Li..'tai One useful addition would be an opening HMO ;m, ,á, ,lFr étik3 library. An effective technique for this is de- . . -r. scribed by Slate and Atkin in their chapter It's TIME you brought your LSI -11 up to DATE. TIME and in Chess Skill in Man and Machine (P W DATE, two important parameters in the computer world, are Frey, editor, Springer -Verlag, New York, available to your LSI -11 on one DUAL SIZE BOARD. When 1977). An opening library provides the user requested, the TCU -50D will present you with the date (month with a challenging set of opening moves and and day), time (hour and minutes), and seconds. Turn your directs the game into situations which are computer off and forget about the time your battery sup- - familiar to the experienced chess player. By ported TCU -50D won't, not for 3 months anyway. The correct including various options at the early choice date and time will be there when you power up. points and using a random selection pro- The TCU -50D is shipped preset to your local time, but can be set cedure, the programmer can insure that the to any time you want by a simple software routine. machine will not always select the same move sequence. The programmer can also AT $295 give the user the option of specifying a YOU CAN'T AFFORD TO IGNORE TIME particular opening against which he would Time is only one way we can help you upgrade your LSI -11 or like to practice. For important matches, the PDP -11 system. We'd also like to tell you about the others. So programmer can prepare surprise openings contact Digital Pathways if you're into -11's. We are too. for the machine in order to gain a psychological edge on the opponent. DIGITAL PATHWAYS INC. 4151 Middlefield Road Palo Alto, California 94306 Telephone (415) 493 -5544 Text continued on page 157

144 December 19780 BYTE Publications Inc Circle 89 on inquiry card. An advanced desktop data system for $1,995? Quitcherkiddin; TANG. Were not kiddin'. Outpost 11 is exactly that. You get: A ruggedly designed unit, Mini -floppy disk drive and intended for heavy use controller Full ASCII keyboard BASIC software package 24 x 80 character CRT Over 20 applications packages 32K bytes RAM available M6800 CPU User documentation Just like this, for only cwwers77/

S'DOS COMPLETE With Outpost 11 and the BASIC software Program MERGE and CHAIN ON ERROR You've been waiting a long time for a Data package, you can: statement String variables and functions System with all these features at a price like Do full floating point BCD math Pro- Trig and math functions GET, PUT and this. Now it's yours. No kiddin'. gram SAVE and LOAD with file names FIELD statements Floppy file processor. *Quit your kidding Order Form r--- Mail to Ouitcherkiddin',TANO. I'm calling your hand. Send me Outpost 11's as described in your ad. Here's my deposit of $200 each, plus $35 freight and insurance. I'll pay the balance on delivery. Name Company /Title Corporation Shipping Address 4521 W. Napoleon Avenue Metairie, La. 70001 Telephone Signature (504) 888 -4884 I Charge my: OA merican Express; Visa; Master Charge' # TWX 810 -591 -5229 L _J Sales Offices: Lo- s Ange- les, CA- 213/426 -7375 Montreal, Canada -514/934 -0000 Boston, MA- 617/969 -4650 Dallas, TX -214/ 358 -1307 Houston, TX- 713/461 -0038 Denver, Col -303/841 -2788 San Francisco, CA- 408/377 -7001 Chicago, IL- 312/830 -0060 Atlanta, GA- 404/252 -6609 Washington, DC- 301/589 -2802 Circle 358 on inquiry card. BYTE December 1978 145 PROCEOURE SCORER; 1 SCORE MATE 1 Listing 1, continued from page 140: BEGIN MOVES(IMOEXIJMTK)).RMHT 1. TRUE; O. INDICATE MATE ) IF MOVES(INDEXIJNTKII.RMCH THEN 1 CHECKMATE ) FUNCTION EVROOK 1 EVALUATE ROOKS 1 VALUE(INOEx(JNTK11 1 610JMTK - IV (AIRS; 10 ROOK LOCATIONS 1 ELSE T. STALEMATE 1 BIRSIITV; 1 SEVENTH RANK ) VALUE(IMOEXIJMTKII t It IF SION THEN VAR NRITELNI' SCOREH')JNTK, JNTN. INOEC (JNTK).VALUE1INOEIIJMTK111)

INTV 1 TV; 1 SCRATCH 1 ENO; 1 SCORER 1

IRTI 1 TIT 1 SCRATCH 1 INTS I TS: 1 SCRATCH 1 INNS 1 RS: 1 SCRATCH 1 FUNCTION SELECT 1 SELECT NEXT NOVE TO SEARCH 1 BEGIN ITC 1 TRUE IF MOVE RETURNED 1 INTV 1. 0: 1 INITIALIZE 1 INNS t. At LABEL IF NXTTSIINRS.INTS1 THEN t LOCATE FIRST ROOK 1 21. 1 NEW SEARCH NOOE 1 BEGIN 22: 1 EXIT SELECT 1 ANORSI INNS, A)ATKFR( INTS11; IF NOT NULRSIINRSI THEN P. ROOK ATTACKS FRIENDLY ROOK ) VAR t. FROWN.: INTV INTV 1 GIVE DOUBLED ROOK CREDIT ) INTO 1 TB; 1 RETURN VALUE 1

ENO; INTK 1 TK; 1. SCRATCH 1

IMiW 1 TAI to WOVE INDEX 1 ROOKS ON SEVENTH ANORSIINRS.A01: 1 1 IHTW 1 TM; 1. SCRATCH 1 IMTI t. CNTRSIINRSII INTV 1 TV; 1 SCRATCH 1 EVROOK 1. INTV INTIINTIFRK7TH: 1 CREDIT ROOKS ON SEVENTH END; C. EVROOK 1

PROCEDURE SELOOM; 1 SELECT Exit - DOME. CALLED MEN NO FURTHER NOVES ARE TO BE SEARCHED BEGIN FROM THIS POSITION. IF XTMVI JNTM)HOVALIJNTKI HAIRS . BSTVL(JMTK -2) THEN THE CURRENT POSITION MUST ( MOVE MILL PRUNE ) HAVE BEEN EVALUATED. 1 INTV t. XTMV(JNTHI HBVAL(JMTKI ELSE BEGIN BEGIN INTO t. FALSE; 1 RETURN NO HOVE SELECTED 1 INTV 1.1 1EVPAWMITPLOCILPI.52.R21 1TPLOC10P1SN.4711 IF SWTR THEN FWMINH 1EVMOOL ILB.LN1 -EVMO01 ION.OM1 1 WRITELNI' SELECT',JNTK.' END.'11 FMMAJMIEVMOBLILN,L01 -EVNOBL10R.00) 1 GOTO 221 1 EXIT SELECT 1 FWROOK IEVROOKITPLOCILRIXRRSIR711 EN01 1 SELDOM 1 -EVROOKITPLOCIORI,KRRS(R211 FWKINGIEVKINGI TPLOCILKI. TPLOCILPII -EVKINGI TPLOCIOKI TPLOCI OPI) 1 01V 64: PROCEDURE SELHOV 1. SELECT EXIT - SEARCH. HAXPS t. HAXIHAXPS,ABSIINTV)II CALICO KNEW A MOVE TO INTV t. xTHV(JMTHIIHBVAL(JNTK),INTV); BE SEARCHED HAS BEEN ENO; FOUND. 1 IF SWTR THEN IAITWI; 1' INDEX TO SELECTED HOVE ) BEGIN WRITE(' EVALU6 ',JMTK.JNTM,IMOExIJNTKI,ENTV1t BEGIN PRINOVIMOVEST INOEC( JMTKIIII INTO t. TRUE( 1 RETURN MOVE SELECTED 1 ENO; INOEX(JMTK11 t. A; 1 POINT TO SELECTED ROVE 1 VALUE(INDEx(JNTKI) t, INUIT 1 RETURN SCORE 1 MOVES(AI.RMSU t. TRUE; 1 FLAG HOVE AS SEARCHED 1 END: 1 EVALU6 1 IF SWTR THEN BEGIN WRITE;' SELECT ',JMTK,OROISRCHH(JMTK1))All PRINOVINOVES(A 111 FUNCTION SEARCH to SEARCH LOOK -AHEAD TREE 1 ENO; 1TM: 1 RETURNS THE BEST HOVE 1 GOTO 221 1 EXIT SELECT 1 ENO: I. SELHOV 1 LABEL 11. t START NEM PLY 1 12. 1 TRY DIFFERENT FIRST HOVE 1 PROCEDURE SELNXT I. SELECT EXIT - MEW MODE. 13. 1 FLOAT VALUE BACK UP 1 CALLED WHEN A NEW SEARCH 14. to FINO ANOTHER HOVE 1 MODE IS TO BE SELECTED 1 15. 1 BACK uP A PLY 1 IAtTHI; 1. HEM SEARCH NODE 91 16: 1 EXIT SEARCH 1 BEGIN IMDEX(JNTK11 t LINOX(JMTK1 -1: 19 RESET MOVES POINTER 1 SRCHM(JMTKI t. AI 1 CHANGE SEARCH NODE 1 PROCEDURE MEMBST 1 SAVE BEST NOVE INFORMATION 1 GOTO 21; 19 EXECUTE NEXT HODE 1 IAtTKI; 1 PLY OF BEST HOVE 1 ENO; 1 SELNXT I

VAR INTM t TW; 1 NOVES INDEx I INRM 1 RM; t SCRATCH 1 PROCEDURE SELANX: 1 SEARCH ALREADY GENERATED ANO NOT ALREADY SEARCHED 'I BEGIN BSTMVIAJ t. INOEX(A11: 1 SAVE BEST HOVE 1 VAR e IF A AK THEN 1 AT FIRST PLY 1 INTM t TN; 1 NOVES INDE( 1 BEGIN INRM t. MOVESIBSTMVIAIII 1 SAVE BEST HOVE I BEGIN FOR INTM I. OSTHVIA) -1 00MNTO AM.; 00 FOR IMTN S. INDEx(JNTK11.1 TO J04TM -1 00 MOVES(INTw11 t. HOVES(INTWII 1 MOVE OTHER MOVES GOWN 1 IF NOT MOVESIINTw).RMSU THEN MOVESIAW11 S. INRM: I. PUT BEST AT BEGINNING 1 SELMOVII NIAI; BSTHVIAK1 t AMI1: V. POINTS TO BEST HOVE I ENO; 1 SELANT 1 ENO ELSE IF NOT MOVES(BSTMVIAJI.RMCA THEN KILLRIJNTKI t= MOVES(BSTMV(A11:1 SAVE KILLER HOVE 1 BEGIN ENO: 1 NEWEST ) 211 I. HEM SEARCH MODE 1 CASE SRCHHIJNTKI OF

HOI t INITIALIZE FOR HEW MOVE 1 BEGIN FUNCTION MINNAX I. PERFORM MINIMAX OPERATION ) MVSEIIJNTK) t. 0: I. CLEAR MOVES SEARCHED 1 IAt TK1 1 PLY TO MINIMAX AT '1 INTV I. BSTVLIJNTK -21; 1 SAVE ALPHA 1 (Tes 1 TRUE IF REFUTATION 1 BSTVL(JMTK -2) t. 2V; 1 INHIBIT PRUNING IN (YALUA 01 HARPS t 01 1 INITIALIZE MAXIMUM POSITIONAL BEGIN SCORE 1 NIMNAX t. FALSE; V. DEFAULT IS MO PRUNING 1 GEHALL; t. GENERATE ALL ROVES 1 IF SWTR THEN FOR ION 1. AW1 TO JMTM -1 00 WRITE(' NINNAI',A,-BSTVLIA-11BSTVL(A1,-BSTVL(Alllt BEGIN IF -11STVLIA11 OSTVL(A) THEN IF UPOATEIHOVESI INTMII THEN BEGIN BEGIN BSTVL(A1 t -OS TVL(A1II IMOEX(JNTK1 1. IMTM( 1 POINT TO CURRENT NOVE 1 NEWBST(A); 10 SAVE BEST MOVE 1 EVALUOT 1 SCORE POSITION 1 HINHAX t. BSTVL(A1) . BSTVL(A -1I1 ENO; 1 RETURN TRUE IF REFUTATION 1 ONDATEtHOVESIINTw11; IF SMTR THEM EN01 MRITEI' NEV BEST. PRUNE; '11STVLIA1) . STVLIA -111; BSTVL(JNTK -21 1. INTV; 1 RESTORE ALPHA 1 EN01 SORTITIVALUE,HOVES,JNTM -111 IF Swift THEN 1 SORT PRELIMINARY SCORES 1 WRITELN 10 PRINT TRACE LINE 1 FOR INTK 1. AK TO ZK 00 ENO: 1 MIMHAX 1 KILLR(IKTK) t. MULNVi 1 CLEAR KILLER TABLE I

146 December 19780 BY TL Publications In 000uí pAGE: 0000 STOCKI.SRC 0000 0000 0000 COBOL (V2'0) 0000 **CIS DIVISION. ++ CATION 0000 IDENTIFICATIONSTOCK-FILE- 000010 FOCUS LTD. 0000 000020 OR. MICRO 0000 AU DIVISION 0000 000030 ENVIRONMENT SECTION 000040 CONFIGURATION MDS-800.900. 0000 000050 SOURCE- COMPUTER. MS 0000 000060 OBJECT-COMpUT R.MD- 0000 0000 000010 INPUT -OUTPUT "STOCK.IT" 000080 PILE ASSIGN 0020 FILE -CONTROL. 000090 STOCK-INDEXED 0020 ORGANTBATION 0020 000100 DYNASTOCK- CODE 000110 ACCESS 0020 000120RECORD KEY 000130 DATA DIVISION. 32. 000140 SECTION. RECORD 000150 STOCK-FILE: FD X(4). 000160 STOCK-ITEM. PIC C(X(24) 000110 O1 02 STOCK-CODE pI pRODUSI2E 000180 02 -SIZE PIC 9141 000190 02 UNIT CO STORAGE VALUE "STOCK"STO- 000200 WORKING-STORAGE cis 000210 PIC X(21) X(591 "DESCRIP' 000220 02 ASK- VALUE 02 X(161 000230 FILLER VALUE " PIC 000240 ASK- Xl S' 02 ST- DESpIC "UNIT 000250 02 X(391' VALUE FILLER X12. 000260 02 SIZE PIC SCREENSCREEN-HEADINGS.- 000210 02 ASK-SIZEREDEFINES p3C X(1b)TC 0002B0 O1 ENT FILLER X141' 000290 02 STOCK-CODE 02 CRT' X(16) X(24) 000300 ?IC pI- 000310 02 FILLER COBOL CRT-PROD-D X1561 0003 02 p1 - PIC 9(4). 000330 p2 FILLER SIZE CRT-UNIT- 0011 000340 02 PIC X. 0016 000350 p2 FILLER PROCEDURE DIVISION. 002F 000360 0030 000310 SRI DiSpLAYOSPACE' 0036 000380 STOCK-FILE. 0040 000390 OPEN I- SCREEN-READINGS. DISPLAY 004E 000400 0065 ENTER-IT' 000410 NORMAL-INPUTCE TO 006F MOVE SPA - 000420 ENTER-IT. 0011 DISPLAY 000430 TO END-1T. CT- ERROR. 0010 000440 gpp. TO CORRE 0083 CORRECT-ERROR.ACCEPT G 000450 STOCK-COEENOT NUMERIC C- 0069 IF CRT- pRODUCT-DES 000460 O 0091 IF pESC T 000410 UNIT -SIZE 009A CET-UNIT-SIZE TTO STOGÓ CODCORRECT ERROR 000480 MOVE TO 009B 000490 MOVE INVALID CRT-STO- 009F 000500 MOVE CRT-CODE-ITEM; WRITE INPUT. 000 000510 - GO To NORMAL 0084 000520 000540 END-1T' STOCK-FILE. From Micro Focus Ltd. 000540 CLOSE SPA - ". 000550 OISpLAY . PROGRAM 000560 DISPLAY 000510 STOP RUN. 000580 LIST CIS COBOL is the Compact, Interactive, Standard COBOL which offers END for the first time a cost- effective key to full commercial use of microcomputers. It can be used simply and naturally, offers facilities unavailable with other forms of COBOL, and produces efficient code without wasting space. For example, a 32K byte sytem is sufficient to run the compiler or a substantial application program. CIS COBOL contains the most relevant parts of the ANSI 74 standard plus extra facilities to provide a powerful interactive business language.

The CIS COBOL Object Pack is available for shipment on IBM compatible diskette to users of a variety of 8080/Z80 based computers running the CP /M* or ISIS* Operating Systems.

Dealer and Application Vendor terms are available Evaluation copy $500 in USA, 2 weeks delivery, payment by cheque, American Express or Visa.

Micro Focus offers a CIS COBOL licencing package to OEM's including access to internal documentation and program source plus an Interfacing Kit to enable CIS COBOL to be implemented quickly in the OEM's own hardware and software environment. The CIS COBOL compiler is itself written in COBOL making it self compiling and thereby extremely portable. MICRO FOCUS LTD 58 Acacia Road, London NW 86AG, ENGLAND, UK Telephone 01- 702 -8843 TLX 28536

CP /M is a trademark of Digital Research and ISIS is a trademark of Intel Corporation. Circle 216 on inquiry card. BYTE December 1978 147 Listing 1, continued..

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1,18 ItIASKITS Vita L o 3at3oaa

9600 BAUD CASSETTE RECORDER An ASYNCHRONOUS NRZ type Recorder with remote motor start /stop. Error rate 108 at 4800 BAUD. Can be used from 110 to 9600 BAUD into a UART - no clocking required. This is not an audio recorder. It takes RS232 or TTL signals from the terminal or computer and gives back the same signals. No audio interface is used. Motor start /stop is manual or through TTL or RS232 signals. Tape speeds are 1.6" / 3.0" and 6.0" per second. 110 volt, 60 Hz, 5 watts. (220 Volts on special order). Can use high quality audio cassettes (Philips Type) or certified data cassettes. Recommended for DATA LOGGING, WORD PROCESSING, COMPUTER PROGRAM RELOADING and DATA STORAGE. Manual control except for motor start /stop. 6800, MODEL CC -9 8080 or Z80 software for file or record searching available on request with order. Used by major computer manufacturers, Bell Telephone and U.S. Government for program reloading $200.00 (4800 Baud) and field servicing. $220.00 (9600 Baud and 220V/50 Hz) AVAILABILITY - Off the shelf.

PROVIDES MONITOR AND TAPE SOFTWARE in ROM. TERMINAL and TAPE PORTS on SAME BOARD. CONTROLS ONE or TWO TAPE UNITS (CC -8 or 3M3B).

This is a complete 8080, 8085, or Z80 system controller. It provides the terminal I/O (RS232, 20 mA or TTL) and the data cartridge I /O, plus the motor controlling parallel I/O latches. Two kilobytes of on board ROM provide turn on and go control of your Altair or IMSAI. NO MORE BOOTSTRAPPING. Loads and Dumps memory in hex on the terminal, formats tape cartridge files, has word processing and paper tape routines. Best of all, it has the search routines to locate files and records by means of six, five, and four letter strings. Just type in the file name and the recorder and software do the rest. Can be used in the BiSync (IBM), BiPhase (Phase encoded) or NRZ modes with suitable recorders, interfaces and software. This is Revision 8 of this controller. This version features 2708 type EPROM's so that you can write your own software or relocate it as desired. One 2708 preprogrammed is supplied with the board. A socket is available for the second ROM allowing up to a full 2K of monitor programs. Fits all 5100 bus computers using 8080 or Z80 MPU's. Requires 2 MHz clock from bus. Cannot be used with audio cassettes without an interface. Cassette or cartridge inputs are TTL or RS232 level. 2S10 (R) CONTROLLER AVAILABILITY - Off the shelf. $190.00, Tested & Assmb.

DOUBLE DENSITY FLOPPY DISK CONTROLLER

A new floppy controller for 5" and 8" drives utilizing the new 1791 chip to provide single or double density recording. Flip the switch to use one or the other mode. Can load memory from single density and re- record it double density on the same drive so you can transfer or re-record your programs and files. Comes with new format program for double density on disk to replace your old single density format program. (Soft Sector IBM format). $295. Assembled and tested. SHIPPING STARTED OCTOBER '78.

PEGASUS DOUBLE DISK ENCLOSURE and POWER SUPPLY

Holds one or two drives, has two drive power supply. 110 or 220V. Comes empty or filled with Shugart drives. Varia- tions preclude listing prices. Call or write for full details.

SHIPPING STARTED OCTOBER '78.

Z 80 BOARD for SWTP COMPUTER

Now you can use the 8080/Z80 software programs in your SWTP 6800 machine. Re- places your MPU board with a Z80 and ROM so that you are up and running with your present SWTP memory and MPS card. 1 K ROM on board replaces MIKBUG and enables you to use XITAN Z80 software which we can supply. AVAILABILITY - Off the shelf. $190.00, Tested & Assmb.

For U.P.S. delivery, add $3.00. Overseas and air shipments charges collect, N.J. Residents add 5% Sales Tax. WRITE or CALL for further information. Phone Orders on Master Charge and BankAmericard accepted. National Multiplex Corporation 3474 Rand Avenue, South Plainfield NJ 07080 Box 288 Phone (201) 561 -3600 TWX 710 -997 -9530 Circle 279 on inquiry card. BYTE December 1978 149 (ANSA; 1 POTENTIAL COMMAND KEYWORO 1 PROCEDURE xxxCM01* 1 PROCEDURE TO EXECUTE Listing 1, continued: COMMAND )

BEGIN IF A THEN FUNCTION RORGNTIVAR LIRAS ITOT 1 GET NEXT TOKEN FROM COMMAND INRA RETURNS TOKEN IN A. BEGIN RETURNS TRUE IF NON -EN0TT xxxCMOT 1 EXECUTE COMMAND 1 TOKEN. GOTO llt ( EXIT 1 A TOKEN IS ANY CONSECUTIVE ENO; COLLECTION OF ALPHANUMERIC ENO: 1 RORCMO ) CHARACTERS. LEAOING SPECIAL CHARACTERS IGNORED. 1 PROCEDURE ROLINE: 1 GET NEIT INPUT LINE FROM USER 1 VAR INTJ I TJT 1 STRING INDEX ) VAR INTC I TC: 1 SCRATCH 1 BEGIN INTJ s TJ: 1 STRING INDEX ) WHILE IJNTJ ZJ1 ANO IOROIILINE(JNTJ11 OR01 -v-11 00 JNTJ s. JNTJ11 BEGIN N: TO 1 A t. R EA DL 1 ADVANCE NEXT LINE INTJ I AAI INTJ 1 AJ: WHILE IJNTJ ZJI ANO IINTJ ZA1 ANO (ILINEIJNTJI IN (- A- .. -9 -11 00 WHILE NOT EOLN ANO IINTJ ZJ1 DO BEGIN BEGIN AUNT.); s ILINE(JNTJII t COPT CHARACTER TO TOKEN 1 READI ICARD( INTJ11: I. COPT INPUT LINE 1 INTJ s INTJIt 1 ADVANCE POINTERS 1 INTJ s. INTJ1: JNTJ I. JNTJlt ENO: ENO; WHILE NOT EOLN 00 RORGNT I. INTJ AA: ( RETURN TRUE IF ANYTHIWG REAOIINTCIT I. SKIP REST OF INPUT LINE 1 MOVED 1 WHILE INTJ ZJ 00 WHILE IINTJ ZJ1 ANO IILINE(JNTJI IN 00 BEGIN JNTJ I JNTJ1i 1 SKIP REST OF TOKEN 1 ICAROIINTJI I. - -I t BLANK REST OF LINE 1 ENOI 1 RORGNT ) INTJ 1= INTJlI ENOS ICAROIZJI 1= . s SET ENO OF COMMANO 1 JNTJ I. AJ: I. RESET INPUT LINE POINTER 1 ENO: 1 ROLINE 1 PROCEDURE RORSFT; ( SKIP FIRST TOKEN IN COMMANO LINE 1 VAR FUNCTION ROPNOvITB: 1 EXTRACT NEXT COMMAND INRA 1 RA: 1 SCRATCH -1 FROM INPUT LINE. INTO s TBI t SCRATCH 1 RETURNS TRUE IF NON -EMPTY COMMANO. 1 BEGIN JNTJ I. AA 1 INITIALIZE SCAN 1 VAR s= INTO RORGNTIINRAII 1 THROW AWAY FIRST TOKEN 1 IMTJ I TJ: I. STORING POINTER 1 ENO: 1 RORSFT -1 BEGIN KMILE IJNTJ ZJ) ANO IICAROIJNTJI = -) 00 JNTJ 1= JNTJ1: T. SKIP LEAOING BLANKS 1 INTJ 1. AJ1 PROCEDURE RORCMO 1 TEST FOR ANO EXECUTE COMMAND WHILE tJMTJ ZJ1 ANO IICARO(JMTJI ; -1 00 EIITS TO COMNANO EXIT IF BEGIN COMMAND IS PROCESSED. ) ILINE(INTJI I= ICARO(JMTJ1: IMTJ 1= IMTJ;: JNTJ 1 JMTJ.1; ENO: IF IICAROIJMTJ) _ :'1 ANO IJNTJ ZJ1 THEN JNTJ 1= JNTJ1: I. SKIP SEMI-COLON 1 RORMOV I. INTJ . AJ; s. RETURN TRUE IF NON -EMPTY ; WHILE IMTJ ZJ 00 BEGIN ILINEIINTJI I. ' If BLANK FILL LINE 1 NEW SOFTWARE FOR IMTJ I. IMTJ:: ENO: YOUR COMPUTALKER! ILINE(ZJI I: '.-: ( STORE COMMANO TERMINATOR 1 JNTJ t. AJI 1. PRESET COMMAND SCAN 1 ENO* 1 RORMOV 1

SOFTWARE PACKAGE 1l FUNCTION RORNUMITIT I. CRACK NUMBER FROM COMMANO LINE. RETURNS NUMBER IF NO ERROR. EIITS TO COMMAND EXIT available now IF ERROR. 1 VAR INTO 1 TB: I. SIGN 1 CTEDIT A new parameter editor INTI I TI: I. VALUE 1 CSEDIT Editor for CSR1 input BEGIN CTEST CT -1 Hardware diagnostic WHILE IJNTJ ZJ1 AND IILINE(JNTJI -) 00 JNTJ t. lt I SKIP LEADING BLANKS 1 PLAY DATA To hear the data files IF ILINEIJNTJI THEN MEMVOICE A vocal memory dumper RESIN INTO I. TRUE; 1 HUMBER IS NEGATIVE 1 KEYPLAY Subr. to play letters /digits JNTJ I. JNTJ.1: I. ADVANCE CHARACTER POINTER 1 PIANO A simple musical keyboard ENO ELSE BEGIN INTO I. FALSE; I. NUMBER IS POSITIVE 1 8080 Assembly Language IF ILINEIJNTJI THEN L * L * L L JNTJ In JNTJ.1: I. SKIP LEADING 1 Sources included END; CPM 8 ", North Star, Micropolis, INTI I. WI WHILE ILINEIJNTJI IN (- 0- .. -9 -1 00 Tarbell, CUTS, MITS ACR, BEGIN IF INTI MAxINT /10 THEN paper tape INTI I. 10INTI.ORDI ILINEIJNTJI I- 0R01 -0 -1 ELSE RORERRI- NUMBER TOO LARGE IT on any of the above media $30.00 JNTJ 1= JNTJ1: 1. ADVANCE 1 calif. res. add 6% sales tax ENO; IF ILINEtJNTJ; IN t- A- .. -Z -1 THEN RORERRI' OIGIT EXPECTED IF INTB THEN INTI 1= -INTI: I COMPLEMENT IF NEGATIVE 1 RORNUM I= INTI: 1 RETURN NUMBER 1 COMPUTALKER CONSULTANTS ENO: 1 RORNUM 1 1730 21st Street, AB PROCEOURE Santa Monica, CA 90404 (MACHO: I. COMMAND - SET UP POSITION 1 VAR (213) 392 -5230 INTM 1 TM: 1 COLOR 1 INTS 1 TS: s POSITION ON BOARO 1

150 December 1978 (0 BYTE Publications Inc Circle 53 on inquiry card. Listing 1, continued: LETONEI- FPAOKF -.FPADCRIFSIII LETONEI- FPADKB '.FPAOCRI F611; LETONE(- FPADKN .,FPAOCRIF7111 LETOMEI- FPADKR -.FPAOCRIFIIII PROCEDURE BOAADV(AITI)1 I. ADVANCE N FILES 1 LETOMEI'FBLOK -,FPBLOKII LETONEI- FPCONN -.FPCONN11 BEGIN MONET" 1; IF INTS.A < IS THEN LETONEI- FRDUBL '.FRDUBLI1 INTS I. IMTS.A LETONEI- FRK7TN 11 ELSE LETONEI- FTRADE -.FTRADEI1 INTS I. OSI LETONEI- FTROSL -.FTRDSLI( ENO( I. BOAADV 1 LETONEI- FTRPOK '.FTRPOKI: LETONEI- FTRPNN -.FTRPNNI( LETONEI- FLAKING -.FNKINGI( LETONEI- I LETONEI'FMN -.FMMINN11 PROCEDURE BOASTO(AITP11 O. STORE PIECE ON BOARD 1 INN LETONEI'FNPNN 11 BEGIN LETONEI'FMRDOK -.FRRDOKII BOARO.RBISIINTSI I. AI LETONE I- HINDOM - .RIMOOM1( RORERRI- NAME IF INTS < IS THEN ILLEGAL LET VARIABLE '11 INTS 1. INTS.:: ENO; ENGT 1 BOAST() ') 211 1 LET CONNANO EXIT 1 ENO( 1 LETCMO 1

BEGIN 1 BOACMO 1 PROCEDURE PLECHOC - CLSTAT; I. CLEAR STATUS FLAGS 1 1 CONNANO PRINT VARIABLE 1 LSTMV I. NULMV: 1 CLEAR PREVIOUS MOVE 1 FOR INTS 1. AS TC ZS 00 LABEL 21i BOARO.RBISIINTSI 1= NT; ( CLEAR BOARD 1 1 PRINT LET COMMAND EXIT 1 INTN I. LITE( PROCEDURE PRIONE INTS'I. 1I 1 TEST FOR AND PRINT VARIABLE 1 REPEAT (A tRA 1 1 TEST VARIABLE MANE 1 IF ILINEI JNTJI IN l' P'.' R '.'N'.'B'.'0'.'K'.i'.'0'.'1'..' 6'1 THEN B ITI11 1 VARIABLE 61 CASE ILINE(JNTJI OF -P -1 BOASTOIXTUNPIEP.INTM)11 B EGIN IF INRA A THEN -R -1 BOASTOIXTUNP(ER.INTNII "N"s BOASTO(XTUMP(EN.INTM111 B EGIN NRITELNIA.B11 'B -1 BOASTOIXTUMPIEB.INTNI)I GOTO 211 C. EXIT -0 -1 BDASTOIXTUNP(EO.INTM111 1 ENO( -K -1 BOASTOIXTUMPIEK.INTNI)I END( I. PRIORE 1 -L -1 INTN I. LITEI '0'1 INTN is OARKI "1"."2"."3"."4"."S"."6"."7","11": BOAADVI0R0IILINEIJNTJII- ORO('0'111 B EGIN I' PLECNO 1 ENO NHILE RORGNTIINRAI DO ELSE B EGIN A- .. -9 -1 THEN IF ILINEIJNTJI IN 1- PRIONEI-FKPSHO '.FKPSN01; BEGIN PRIONEI-FKSANO '.FKSAN01; FOR INTS 1= AS TO ZS DO

PRIONEI-FNAXMT '.FMAXMTIS . BOARD.RBISIINTSI Is NTT PRIONEI-FNODEL '.FNOOELI: CLSTAT; 1 CLEAR STATUS 1 RIONEI-FPADOR '.FADCRIFlIIt RDRERRI- ILLEGAL BOARD OPTION -l; PRIONEI-FPADON '.FPAOCR(F211( END; RIONEI-FADOB -.FADCRIF3111 JNTJ I= JNTJ.:; PRIONEI-FPADOF -.FPADCRIF611( UNTIL JNTJ = 2J% PRIONEI-FADKF -.FADCR(FS11( ENO: 1 BOACMO 1 PRIONEI-FPADKB -.FADCRIF611( PRIONEI-FADKN -.FADCR(F711( PRIONEI-FPAOKR -.FPAOCR[F611: PROCEDURE ENDOW; 1 COMMAND - END PRDGRAN 1 PRIONEI-FPBLOK '.FBLOK1: PRIONEI-FPCONN '.FPCONNI: B EGIN PRIONEI-FPFLNX 1( GOTO 9; I. ENO PROGRAM 1 PRIONEI-FRDUBL '.FROUBLI: ENO; 1 ENOCNO 61 PRIONEI-FRK7TH '.FRK7TH17 PRIONEI-FTRADE -.FTRADEI: PRIONEI-FTROSL '.FTRDSLI( PRIONEI-FTRPOK -.FTRPOKI: PROCEOURE GONCNDI 1 COMMAND - GO N MOVES 1 PRIONEI-FTRPNN '.FTRPNNIS PRIONEI-FMKING '.FNKINGI: B EGIN PRIONEI- 11 GOING 1= RORNUMI I. CRACK NUMBER 1 PRIONEI-FKNINM '.FNNINMIT IF GOING <. 0 THEN PRIDNEI- '.FNPANN1i GOING 1= l; PRIONEI-FNROOK '.FMROOK11 GOTO tt to EXECUTE MACHINES MOVE 1 RIONEI-NINDON -.KINDONI; ENO; 1 GONCND .1 RDRERRI- ILLEGAL VARIABLE NANE '11

211 1 PRINT LET CCNNAND EXIT 1 ENO: PROCEDURE INICNOI ( CONNANO - INITIALIZE FOR A NEU ENO; 16 PLECMD 1 GANE 1

B EGIN GOTO II I. INITIALIZE FOR A NEM GANE 1 PROCEDURE PRICMD( 1 CONNANO - PRINT BOARD 1 ENOi C. INICNO '1 B EGIN IF RDRGNTIINRAI THEN PRINTBINBDRDI PROCEDURE LETCNDI ( COMMAND - CHANGE VARIABLE 1 ELSE PRINTBIBOARD.RBISPI LABEL ENO: to PRICMD '1 211 16 LET CONNANO EXIT 1

PROCEDURE LETONE to TEST FOR ANO SET ONE VARIABLE 1 PROCEDURE PAMCMOI 1 COMMAND - PRINT ATTACK MAP 1 IAIRAI to VARIABLE MANE 61 VAR BITIII to VARIABLE 1 B EGIN W HILE RORGNTIINRAI DO BEGIN IF INRAIAAI -T- THEN IF A INRI THEN PRINANIATKTO1 B EGIN ELSE B I= RORNUM: 1 GET VALUE 1 IF INRA(AAI . 'F- THEN LOTO 21: I. EXIT 1 PRINANIATK FRI END( ELSE END; 1' LETOME 1 RDRERRI- ATTACK MAP NOT 'TO. OR 'FROM -11 ENDS 1' PAMCMO 1

B EGIN IF RORGNTIINRAI THEN PROCEDURE POPCMO: C. COMMAND - PRINT DINER STUFF 1 B EGIN LETONEI-FKPSHO '.FKPSNOIS LETONEI-FKSANO '.FKSANO)i VAR 1 1 CASTLE TYPE INDEX 1 LETONEI-FMAXNT '.FMAXNTII INTO TOI LETOMEI-FNODEL '.FNOOELI: LETONEI-FPAOOR -.FPADCRIFlIIt B EGIN LETONEI-FPAOON '.FPADCRIF211: W ITH BOARD DO LETONEI-FPAOOB -.FPADCRIF111: B EGIN LETONEI-FPADOF '.FPAOCRIF411: NRITELNIXTMAIRBTNI.- TO MOVE. -11

December 197X © BYTE Publications Inc 151 BDARO.RB50 T. BDARD.RB50 (OS11 Listing 1, continued: ENO; 1 STACAK 1

NRITELMIRBTS,' ENPASSANT."); PROCEDURE STACAO: I. ALLON CASTLE QUEEN SIGE 1 NRITELMI'MOVE NUMBER',RBTI1; FOR INTO 1. LS TO OL DO BEGIN IF INTO IN RBSO THEN IF IMTM = LITE THEN WRITELN(XTQAUINT01,- SIDE CASTLE LEGAL.-11 BOARO.RB50 1. BOARO.RBTQ ILL1 ENO; ELSE ENO; 1 POPCMO "I BOARO.RB50 1= BOARD.RBSQ IOL1; ENO; I. STACAQ 1

PROCEDURE PMVCMO; 1 COMMANO - PRINT MOVE LIST 1 PROCEDURE STAORK; 1 SET BLACK OPTIONS 1 VAR INTN 1 TW; 1 MOVES LIST INDEX 1 BEGIN IMTM 1. DARK; BEGIN ENO( 1 STAORK 1 LSTMOV; 1 LIST LEGAL MOVES 1 FOR INTN 1= AN TO JNTW -1 DO BEGIN NRITE(INTWIG,- -1: PROCEDURE STAEMP; I. SET ENPASSANT FILE 1 PRIMOVIMOVES(INTN111 IF INTN /LPP + INTN DIV LPP THEN BEGIN PAUSER: IF NOT RORGNTIINRAI THEN ENO; BEGIN ENO; 1 PMVCMO I CLSTAT; I. CLEAR STATUS 1 RORERRI- ENPASSANT FILE OMITTED '1: END;

PROCEDURE SWICMO: 1 CORNANO - FLIP SNITCH 1 STAEPFI'OR ',F111 STAEPFI'0N ',F21; LABEL STAEPFI'QB ',F31; 21; I. SNITCH OPTION EXIT 1 STAEPFI'0 ',F101 STAEPFI'K ',FS); STAEPFI'KB ',F611 STAEPFI -KN ',FT); PROCEOURE SNIONE C. PROCESS ONE SWITCH 1 STAEPFI'KR ',F81; (AIRA: I. SNITCH NAME 1 CLSTAT; 1 CLEAR STATUS 1 VAR BIM; t SNITCH 1 RORERRI' ILLEGAL ENPASSANT FILE '1: ENO; I. STAENP 1 VAR IMTJ 1 TJ; I" SAVE COMMANO INOEX 1

BEGIN PROCEDURE STAGOS; 1 SET SIDE TO MOVE 1 IF INRA = A THEN BEGIN BEGIN IMTJ I. JMTJ; 1 SAVE CURRENT POSITION 1 BOARD.RBTM 1. INTM1 IF RORGMTIIMRA) THEN JNTM 1. INTMi BEGIN ENO I. STAGDS 1 IF INRA + -ON THEN B 1= TRUE 1 TURN SWITCH ON 1 ELSE IF INRA . 'OFF ' THEN PROCEDURE STALIT; U. SET WHITE OPTIONS 1 B I. FALSE 1 TURN SWITCH OFF 1 ELSE BEGIN JNTJ I= IMTJ: I. RESTORE CURRENT POSITION IMTM 1= LITE; PRIS WIIA,B1; 1 PRINT SNITCH VALUE 1 ENO; I. STALIT 1 ENO ELSE PRISNIIA,B1; LOTO 211 I. SNITCH OPTION ExIT 1 PROCEDURE STAMUM: I. SET MOVE NUMBER 1 END; ENO; 1 SWIONE 1 BEGIN BOARO.RBTI I= RORMUM; ENO; I. STAMUM 1 BEGIN 1 SNICMO 1 211 1 SNITCH OPTION EXIT 1 WHILE RORGMTIINFAI 00 PROCEDURE STAOPT 1 TEST STATUS OPTION 1 BEGIN CAIRA; I. TEST OPTION 1 SNIONEI'EC '.SNEC1: PROCEDURE STAxxxl; I. PROCEDURE TO EXECUTE IF SNIONEI'PA -,SNPA1: EQUAL 1 SNIONEI -PS - ,SNPS1; SWIONEI'RE - ,SWRE1: BEGIN SNIONEI'SU - ,SWSU); IF INRA = A THEN SNIONEI'TR ',SNTR); BEGIN RORERRI' INVALID SNITCH OPTION '1; STAXxx( I. EXECUTE PROCEDURE 1 ENO; LOTO 211 1 ExIT STATUS OPTION 1 ENO; 1 SNICMO 1 ENO( ENO; I. STAOPT 1

PROCEDURE STACMO: 1 COMMAND - STATUS CHANGES 1 BEGIN 1 STACMO 1 LABEL CLSTAT; 1 CLEAR STATUS 1 211 I. STATUS COMMAND OPTION EXIT 1 INTN I. LITE; 1 DEFAULT SIDE WHITE 1 VAR 211 1' STATUS OPTION ExIT 1 INRA 1 RAI 1 CURRENT TOKEN 1 WHILE RORGNTIINRAI DO INTN t TH1 1 SIDE BEING PROCESSED 1 BEGIN STAOPTI -0 ',STADRKI: STAOPTI -EP ',STAEMP); STAOPTI'G ',STAGOSIT PROCEDURE STAEPF 1 PROCESS EP FILE 1 STAOPT I'L ',STALIT)( (AIRAI 1 TEST TOKEN 1 STAOPTI'N ', STANUM11 BITF1; I. EQUIVALENT FILE 1 STAOPTI'00 ',STACAKI( STAOPTI'000 ',STACAQI( BEGIN CLSTAT; IF A INRA THEN RORERRI' INVALID STATUS OPTION '11 BEGIN ENO; IF INTN LITE THEN ENDS I. STACMO 1 BOARO.RBTS I. XTRFSIR6,B1 ELSE BOARD.RBTS t. xTRFSIR3,B1; LOTO 211 1 EXIT STATUS OPTION 1 PROCEDURE NHACMO; 1 COMMAND - WHAT? 1 END; ENO; 1 STAEPF 1 BEGIN NRITELNIMOVMS)S I. PRINT LAST MESSAGE 1 ENO; 1 WHACMD 1 PROCEDURE STACAK: 1 ALLOW CASTLE KING SIDE 1

BEGIN BEGIN 1 READER 1 IF IMTM = LITE THEN 111 1 COMMAND ExIT 1 BOARO.RB50 I. BOARO.RB50 (LS) WHILE NOT RORMOV 00 ELSE ROLINEI

152 December 1978 © BYTE Publications Inc Listing 1, continued: FUNCTION DIFFER 1 COMPARE MOVES 1 1A. B(RM) I. NOVES TO COMPARE 1 (TB) 1 TRUE IF MOVES ARE DIFFERENT ) IF SMEC THEN B EGIN 1 ECHO LINE ) VAR . RITE1^ -1: INTB s TB; 1 SCRATCH ) FOR INTJ I. AJ TO 2J-1 DO .RITEIILI))E(INTJIII B EGIN .RITEL)): INTB a IA.RMFR <. B.RKR1 OR ENO: IA.RMTO <. B.RMTD) OR IF ILI))E(AJ.1I IN f-..-.-.-Y-.-I-I THEN IA.RMCP <. B.RMCP)) BEGIN IF A.RMPR B.RMPR THEM INRA I - 1 EXTRACT KEYWORD ) IF A.RMPR THEN INRA(AA1 I. ILIME(AJ1: DIFFER I INTB OR (A.RMPP <. B.RMPP1 INRA(AA.11 I. IIINE(AJ.11: ELSE RORSFT: 1 SKIP FIRST TOKEN ) IF .RM00. B.RMDO TMEN RORCMDI-BO -.BOACM01: IF .RSOO THEN RORCM01-EN -.ENDCM01: DIFFER 1. INTB OR IA.RMOS <. B.RMQS) RDRCM01-G0 -.GONCM01: ELSE RDRCMD(-IN -.INICMDI: DIFFER a INTB RDRCMDI-LE -.LETCMDI: ELSE RDRCMO(-PB -.PAMC)101: DIFFER I. TRUE RDRCMDI-PO -.POPC1401: ELSE RDRCMDI-PL -.PLECMD11 DIFFER 1 TRUE; RORCN01-PM -.PMVCM01: ENO; 1 DIFFER ) RDRC)IDI-PR -.PRICMDI) RDRCMDI-ST -.STAC)I01( RORC1101-S. -.SMICMO); RORCNDI-.H ^.MHACM01: PROCEDURE SETSQD I. DEFINE SPECIFIC SQUARE RDRERRI- INVALID COMMAND -1( DESCRIPTOR 1 END: IA ITSt I. SQUARE TO DESCRIBE ) BIRO; ENO: I. READER / 1 SYNTAX TO USE 1 VAR CISR: 1 SET OF POSSIBLE RANKS 1 VAR D15F1( 1 SET OF POSSIBLE FILES 1

PROCEDURE MINENG B EGIN 1 GENERATE MINIMUM C I. (R1..RB1( I. INITIALIZE TO DEFAULTS .1 ENGLISH NOTATION 1 (F1..FB1: 1IRM) 1 MORE TO NOTATE I D 1= B)RA); WITH B DO 1 LEADING COMMENT ) B EGIN VAR IF RDKO AND RDNB THEN D 1. IXTSFIA11( INTN I TN) 1 MESSAGE INDEX I IF (NOT RDK01 AND RDMB THEN CASE XTSF(A1 OF PROCEDURE DDCHR I ADD CHARACTER TO MESSAGE ) F1.F6 (BITC11 IFI.F$7; I CHARACTER ) F2.F7) 3. [F2.F7I) F3.F6) (F3.F6IT B EGIN F4 v (F41) MOVMSIINTN1 A; 1 ADD CHARACTER 1 FS I 1a IFS]: IF INTN < ZN, THEN END( INT)) I. INTN.1; 1 ADVANCE POINTER ) IF RDRK THE END: 1 OOCHR 1 C I. (XTS (All( END; END; 1. 5ET500 1 PROCEDURE ADDSQR 1 ADD SQUARE TO MESSAGE 1 (A ITS; ( SQUARE TO ADD ) BIRD): 1 SQUARE SYNTAX 1 PROCEDURE RINGEN 1 PRODUCE MINIMUM ENGLISH NOTATION FOR B EGIN MOVES AND CAPTURES ) MITM B 00 1AIRM; 1 MOVE OR CAPTURE 1 B EGIN RITI: I. FIRST SYNTAX TABLE ENTRY 1 IF ROPC THEN CT111 I. LAST SYNTAX TABLE ENTRY DDCHRIXTUCITPU(NBORD(BI) I); 1 IF RDSL THEN LABEL OOCHRI / ^1: - 21. I. EXIT AMBIGUOUS MOVE SCAN 1 IF ROKO THEN 1 EXIT RINGER 1 IF XTSF(AI IN (F1..F41 THEM 22t DOCHRI -0 -1 VAR ELSE INTG TG: I. PROMOTION PIECE 1 ADOCRRI -K -1: INTI TI: 1 SYNTAX TABLE INDER ) IF RONB THEN INT. TM: I. MOVES INDER 1 CASE XTSF(A1 OF INLR SR: I. RANKS DEFINED ON LEFT 1 F1.FB3 OOCHRI -R -1: IMRR SR( 1 RANKS DEFINED ON RIGHT 1 FZ.F7) DOCHRI -N-1: INLF SF; I. FILES DEFINED ON LEFT ) F3.F6 AOOCNRI ^B-1: INRF 5F1 I. FILES DEFINED ON RIGHT 1 F4 I OOCHRI-O -1: F5 I AOOCHR / ^K -); BEGIN END; FOR INTI I. B TG C DO / FOR EACH SYNTAX ENTRY 1 IF RDRK THEN MITN SYNTR(INTI1 DO IF JNTM = LITE THEN BEGIN CASE RTSRIA1 OF IF A.RMPR THEN R1. OOCHRI -1 -1: INTO I A.RMPP R2) AOOCHRI -2 -1: ELSE R3, OOCHRI ^3 ^1: INTG 1= PB: R4) OOCHR( ^4 ^1: SETSOOIA.RMFR.RYLS.INLR.INLF1( I. SET SQUARE SETS 1 R5 DOCHR1 -5 -1: SETSQOIA.RMTO.RYRS.INRR.INRF1: R63 DOCHRI -6 -1t -7 FOR INT. I. ..1 TO JNTM -1 00 R7) ADOCHR1 -1: IF DIFFERIMOVES(INT.I.A1 THEN RBI AOOCHRI -8-1: IF INBORD(A.RMFRI = NBORDIMOVES(INT.I.RMFR11 AND END (A.RMCP MOVESIINT.I.RMCP1 THEN ELSE MITM MOVES(INTMI DO CASE YTSR(A) OF IF IRTSR(RMFRI IN INLR1 AND Rl) OOCHRI -B -1: IRTSRIRMT01 IN INRR1 AND R23 OOCHR1 -7 -1: IRTSF(RMFRI IN INLF1 AND R33 AOOCHR1 -6 -1; IXTSF(RMTDI IN INRF) AND R4, OOCNR( -5 -1: ((RMPR AND IINTG RMPP)) OR (NOT RMPR)) THEM R5) OOCHRI ^4 ^1) GOTO 21; 1 ANOTHER MOVE LOOKS THE SAME 1 R6, DOCNR1-3-11 R73 AOOCHRI ^2-1: I. NO OTHER MOVE LOOKS THE SAME ) RBI OOCHR1 -1 -1: OOSORIA.RMFR.RYLS); 1. ADO FROM SQUARE ) END( DOCHRIRYCH1( 1 ADD MOVE OR CAPTURE 1 ENO; DOSORIA.RMTO.RYRS1: I. ADO TO SQUARE 1 END; 1 OOSOR 1 GOTO 22; 1 EXIT BINGEN 1 21. 1 TRY NEXT SYNTAX 1 END; 22. I. EXIT RINGEN 1 PROCEDURE AOOIRO 1 ADO MORO TO MESSAGE 1 END) 1 RINGER 1 IAMBI 1 TEXT OF MORD ) 1 LENGTH Of MORO ) BEGIN 1 MINENG ) VAR MOVES I. - INT I TAI 1 CHARACTER INDEX ) 1 CLEAR MESSAGE 1 INTN t )).1: 1 INITIALIZE MESSAGE INDER ) BEGIN OO.R01B.2A1: 1 ADD INITIAL COMMENT 1 FOR INT I. AA TO B DO OD.RD1-- -.21: DOCHRIA(INTAI); MITH DO END; 1 OOMRD 1 BEGIN

December 1978 (fl BYTE Publications no 153 JNTJ I. JNTJ.1T I. SKIP BLANKS 1 Listing 1, continued: INTC t. ILINEIJNTJ)t I. NEXT CHARACTER 1 IF (INTC .1 OR (INTC 1.) THEN GOTO 1St 1 EXIT SCAN 1 ENDI NCHIN 1 INTBS I RETURN TRUE IF CHARACTER IS IF RMOO THEN 1 CASTLE I NOT IN STRING 1 BEGIN ENOt NCHIN AOOW1101.0 -0 -.311 1 1 IF RHOS THEN AODWA01 -0 .211 ENO I. FOUND A MOVE. EXITS ELSE 1 NOT CASTLE I PROCEDURE YRMHITt 1 CAPTURE 1 TO AMBIGUOUS MOVE IF THIS IF RMCA THEN POSSIBLE MINGENIA. SYNCF.SYNCL) IS THE SECOND MOVE. THE MOVE I. SIMPLE MOVE 1 SAVES IN INRM ELSE OTHERWISE. MINGEN(A.SYMMF.SYNMLIt 1 IF RHPA THEN 1 PROMOTION 1 BEGIN BEGIN I. SECOND POSSIBLE MOVE AOOC HRI.lt IF IFMV THEN GOTO 171 1 TRUE; 1 FIAT POSSIBLE MOVE AOOCHRIXTGC(RMPP11t IFMV I. 1 INRM 1. MOVESIINTWIL I. SAVE MOVE '1 ENO: AOOWR01. -01: ENOt 1 YRMHIT .1 IF RHCH THEN I. CHECK ) BEGIN AOOWR01CHECK .511 PROCEDURE rRMCOMi I. TRMHIT IF RMMT THEN I. CHECKMATE 1 COMPARE SQUARES. CALLS A001001-MATE .Al; IF MOVES(INTMI MOVES THE AOOCHR(..1; RIGHT TTPE OF PIECE. CAPTURES ENO THE RIGHT TYPE OF PIECE, ANO ELSE MOVES TO ANO FROM POSSIBLE IF RMMT THEN 1 STALEMATE 1 SQUARES 1 AOOWROI.STALEMATE..101t ENO: BEGIN ENO; 1 MINENG 1 WITH NOVES(INTMI DO IF 1XTSR(RMFRI IN INIR1 AND IXTSF(RMFRI IN INLF) ANO IXTSR(RMT01 IN IMRR1 ANO PROCEDURE MTNOVE: 1 MAKE MACHINES MOVE 1 IXTSFIRMTD) IN INRFI ANO (NOT RMILI ANO VAR (BOARD.RBISIRMFRI = INTPI THEN . INRM 1 RN: I. THE MOVE 1 IF RMCA IFCA THEN IF RMCA THEN BEGIN IF RMCP INCP THEN CR EA TEt 1 INITIALIZE DATA BASE 1 YRMHIT INRM 1. HOVESISEAFCHIS 1 FIND THE BEST MOVE 1 ELSE IF INRM.RMIL THEN ELSE BEGIN 1 NO MOVE FOUND 1 TRMHITI

GOING I= DI ENO: 1 TRMCOM I IF LSTMV.RMCH THEN I CHECKMATE 1 NRITELNI CONGRATULATIONS..) ELSE F. STALEMATE 1 NRITELNI. DRAWN. 1 PROCEDURE TRMCAPt 1 SEMANTICS CAPTURE 1 ENO ELSE BEGIN BEGIN IFCA I. TRUE; MINEHG(INAN.' MY MOVE '11 1 TRANSLATE MOVE TO ENGLISH END: 1 YRMCAP I WRITELN(MOVMS1t I. TELL THE PLAYER ) THEMOV(INAM11 1 MAKE THE MOVE 1 IF SWSU THEN WRITELN(BOARO.ABTI...NODES. NOOES...BSIVL(AKIIt PROCEDURE TRMCASt I SEMANTICS CASTLE I ENO; ENO; ( MTMOVE 1 BEGIN IFOO I. TRUEt ENO: 1 TRMCAS 1 PROCEOURE VRMOVEt 1 MAKE PLAYERS MOVE 1

LABEL PROCEDURE YRHCPCI I. SEMANTICS CAPTURED PIECE '5 11. 1Z. 13. 14, IS. 1. SYNTAX MODES 1 16. O. SYNTAX ERROR 1 BEGIN 17. 1 AMBIGUOUS MOVE 1 CASE INTC OF le: 1 NORMAL EXIT 1 P1 INCP A. XTUMPtEP.OTHER(JNTMIIt R1 INCP 1. XTUMPIER.OTHER(JNTMIIt vAR N1 INCP 1. XTUMPIEN.OTHER(JNTM)It INTB I TB: 1 VALID MOVE FOUND 1 BI INCP I. XTUMPIEB.OTNER(JNTMIIT INTC 1 TCt 1 CURRENT CHARACTER 1 0.1 INCP 1. XTU)PIE0.OTIlER(JNTMIII !NTH I TJt 1 MOVES INDEX 1 ENO; ENO: 1 YRMCPC 1 INTP I TP: 1 MOVING PIECE 1 INCP I TP; 1 CAPTURED PIECE ) IFCA 1 TBt O. CAPTURE 1 I O. IFPR TBt PROMOTION 1 PROCEDURE TRMCOSt 1 SEMANTICS - CASTLE LONG 1 IF00 t Tet O. CASTLE 1 IFOS t TOT O. QUEEN SIDE CASTLE 61 BEGIN INTG 1 TG; 1 PROMOTION TYPE 1 IFOS I. TRUE; IFMV I TBt 1 MOVE FOUND 1 ENO: 1 TRMCOS 1

IFLO 1 TB; I R. N. OR B ON LEFT 1 IFLF I TB; 1 K OR 0 ON LEFT 1 IFRO 1 TBt 1 R N. OR B ON RIGHT 1 PROCEDURE TRMLKOI I. SEMANTICS - K OR 0 ON LEFT 1 IFRF I 1ST K OR 0 ON RIGHT 1 BEGIN INLF 1 Sit I. FILES ON LEFT 1 CASE INTO OF INLR 1 SRt 1 RANKS ON LEFT I K1 INLF 1. IFS..Fe1 INLF: F. KING SIDE 1 INRF I SF; I FILES ON RIGHT 01 -Q1 INLF I. IF1..F41 INLF; 1 QUEEN SIDE 'I INRR 1 SRI O. RANKS ON RIGHT 1 END; IFLF I. TRUE: INRM I RR: I. THE MOVE ) ENO: 1 TRMLKQ 1

FUNCTION NCHIN 1. DETERMINE IF NEXT INPUT CHARACTER IS NOT IN A GIVEN SET .1 PROCEDURE TRMLRBt 1 SEMANTICS - R. N. OR B ON (AISCt I. SET OF CHARACTERS TO CHECK 1 LEFT 1 PROCEDURE TRMXXXI 1 SEMANTICS ROUTINE TO CALL IF NEXT CHARACTER IS IN SET 1 BEGIN ITBL 1 TRUE IF CHARACTER IS MOT IN CASE INTC OF SET 1 R -1 INLF I. tFt.FR) INLF¡ 1 ROOK FILE I -N -1 INLF I. tF2.F7) INLF; 1 KNIGHT FILE I VAR BI INLF 1= IF3.F61 INLF: I' BISHOP FILE 1 INTB 1 TOT 1 SCRATCH ) ENO: IFLO I. TRUE: BEGIN ENO: 1 TRMLRB I INTB t. NOT (INTC IN A1; IF NOT INTB THEN BEGIN TRMXXXI 1 EXECUTE SEMANTICS ROUTINE 1 PROCEDURE TRMLRK: I SEMANTICS - RANK ON LEFT 1 JNTJ 1. JNTJ.11 1 ADVANCE PAST CHARACTER 1 WHILE (JNTJ IA BEGIN ANO 1(ILINE(JNTJI 1 OR (ORO(ILINE(JNTJ11 ORO(IC111 00 IF JNTM LITE THEN

154 December 1978 © BYTE Publications Inc Computer Chess

CHESS SKILL IN MAN AND CHESS AND COMPUTERS by MACHINE edited by Peter W David Levy. Frey. Chess and If you enjoy playing game endless varia- A of chess, then you will thor- tions, chess has challenged Computers oughly enjoy this book, our skill for centuries. This David levy which is loaded with chess book surveys our current games played by computers. understanding of human The first chapter describes chess skill and covers the the earliest chess "ma- subtleties of coaxing a machine," the famous Auto- chine to play chess. The ini- maton chess player that tial chapter and appen- toured Europe and America. dix present a brief history There is a detailed account of the computer chess tour- of Torres y Quevedo's in- naments. The next two vention that played the chapters describe the essen- ending of King and Rook tials of how humans and against King. There is also a computers play chess. The description of how com- fourth chapter provides a puters play chess, including detailed description of the an account of early Soviet Northwestern Chess Program, attempts at chess program- currently the national champion. ming that contains much The following three chapters discuss several di,e information hitherto unpub- alternative approaches to chess program- d p'; lished outside the Soviet Union. In ming. the final chapter, a former cap- 6f.9' dyJ fb'R I p+' Many examples of computer play tain of the U.S. Olympic chess team asses- SO Ix are given, which provide an excellent ses the present status of chess skill in human 9C6 Ill} insight into the problems facing chess and machine. 217 pp. $14.80 hardcover. programmers. 145 pp. $8.95.

1975 U.S. COMPUTER CHESS CHAMPIONSHIP by David Levy. 1976 U.S. COMPUTER CHESS CHAMPIONSHIP by The sixth annual U.S. Computer Chess Championship, held David Levy. in October 1975, was a tournament in which twelve computer pro- This book includes a detailed analysis and des- grams competed against each other. This book includes a detailed cription of all the tournament games played at the analysis and description of all the games, presented by David Levy, seventh annual U.S. Chess Championship held in Octo- the tournament director. 86 pp. $5.95. ber 1976. 90 pp. $5.95.

AN EDITOR /ASSEMBLER SYSTEM FOR 8080/8085 BASED COMPUTERS by WJ Weller and W T Powers. This 148 -page book contains complete information for initializing and using a powerful new A New Book! editor /assembler and debugging monitor system, and the full SOURCE text of both. The assembler fully supports all Intel instruction mnemonics as well as the entire language used in PRAC- TICAL MICROCOMPUTER PROGRAMMINGTM: THE INTEL 8080. The editor /assembler is resident in less than 8K RAM and will run on any 8080, 8085 a Z80 based computer with peripherals which transfer on a character by character basis or can be made to do so by buffering. The user supplies his own I/O drivers. The text editor is extremely simple to use and does not require irrelevant line numbers. Also included is a program to convert Processor TechnologyTM format tapes to a format useable by the editor /assembler. This system is not the usual "quickie" software, riddled with errors and limitations, but a professionally created, thoroughly tested and debugged system. At $14.95 it is the best software bargain you are ever likely to see. AND BY THE WAY... paper tape object copies of all of this software are sent FREE to book purchasers when the coupon at the back of the book is returned to Northern Technology Books. 81/2 x 11 format. $14.95.

For your convenience in order- STANDARD DICTIONARY OF COMPUTERS AND INFORMATION PROCESSING 2nd Edition by Martin ing, please use this page plus the order form on page 138. H Wei k. DIAL YOUR BANK CARD This is a very complete, fully cross -referenced dictionary. It goes a step farther in that it ORDERS TOLL FREE includes full explanations, practical examples, many pertinent illustrations, and supplementary (800) 258 -5477. information for over 12,500 hardware and software terms. It cross -references the terms to other closely related concepts, and appended to each definition, as the need arises, are explanations, tutorial information, examples, usage areas, and cross -references for further clarification of con- ßITS inc cepts and meanings. 390 pp. $16.95 hardcover. (No photo)

Circle 35 on inquiry card. BYTE December 1978 155 Lirting 1, continuerP

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Text continued from page 144

A second and somewhat more challenging project would be to develop a transposition table for the program. This requires the availability of unused memory (at least 8 K bytes and preferably 16 K or 32 K bytes), an efficient hashing scheme, and a set of decision rules to select among positions when a collision occurs (ie: two positions Look to North Star hash to the same address in the table). Another problem is that the use of a staged And Computer Enterprises evaluation process and the a -ß algorithm For often provides an imprecise evaluation score Unbeatable Prices. (ie: the machine has determined that a position was not optimal but has not invested The North Star Horizon Computer System. the time to find out exactly how bad it was). (With wooden cover and all standard items.)

If the programmer succeeds with the trans- Item List Cash position table, however, move calculation Code Description Price Price NS -H -1 Horizon 1 kit $1599. S1299. will take 30 to 50 per cent less time in most NS -H -1 /A Horizon 1 Assembled $1899. S1559. NS -H -2 Horizon 2 kit $1999. S1639. middle game positions and 60 to 90 per cent NS -H -2 /A Horizon 2 Assembled $2349. S1926. less time in many end game positions. North Star S -100 Boards NS -ZPB Z -DOA 4 mhz Processor kit $ 199. S 163. A third area for improvement is the eval- NS -ZPB /A Z -80A 4 mhz Processor Assembled $ 259. S 212. uation function. Our program presently has NS -16K 16K 250ns RAM kit $ 399. S 327. NS -16K /A 16K 250ns RAM Assembled $ 459. S 376. only a rudimentary function. The reader should compare it with the one used by Chess 4.5 which is described in detail by Slate and Atkin. Their evaluation function provides an excellent starting point for re- vising our present function. In part 4 we will P O. Box 71 Fayetteville, N Y 13066 discuss the advantages of using a conditional evaluation function, ie: one that changes depending on the stage of the game and on the It's A Great World . presence of special features. One implemen- Big Computer .. tation of this strategy is the special end game ... but you only need program described by Monroe Newborn in Chess Skill in Man and Machine. The Computer Corner It is appropriate for us to add two important disclaimers at this juncture. Although we have carefully tested each of the routines in the program and played several chess games, it is still possible that there are a few minor bugs in the program. If you find one, a letter to one of us or to BYTE would be appreciated. Secondly, our chess program was written primarily for pedagogical purposes. For this reason it is not a production program and does not run very efficiently. If you are the competitive type, our program should provide many useful ideas, but you should not expect it to compete successfully in tournament play unless you make extensive modifications and additions. Don't know "bytes" from "bagels "? computers. Courses range in scope The courses given in our Seminar from "Introduction to Home Com- A chess program has a tendency to grow Room will get you "up and running ". puters" to "Professional Business and change its personality as the program- From home computerists to busi- Systems." Scheduled classes will ness people, our professionals include appropriate course mate- mer becomes more familiar with each of its have a course for you. rials and instruction by computer many limitations. It provides a constant We offer classes with a hands -on professionals. challenge for those of us who are too com- approach using various micro- Processor Technology SOL pulsive to tolerate obvious weaknesses. In Commodore PET & KIM fact one must be careful not to become North Star HORIZON APPLE II totally obsessed with this project. We do not l wish any of you to lose your job or your (compu White Plains Mall, 200 Hamilton Avenue spouse because of a chess program. White Plains, N.Y. 10601. (914) WHY -DATA corner Hours: Daily 8 Sat. 10 -6, Thurs. 10 -9 Circle 65 on inquiry card. December 1978 © BYTE Publications Inc 157 Continued from page 10 plex problem can be handled with small, LIGHT SEEKING ROBOT easy to understand pieces of code. One recovery from transmission errors. Add of the thoughts about module size is, I enjoyed your "On Building a Light - to this the fact that the protocol has therefore, that a module ought to be Seeking Robot Mechanism" article page been in service a number of years, and able to fit on one printed page. This is so (August 1978 BYTE, 24). The sonar description caught my eye, since I I am sure readers will find the literature that all the information about the worth reviewing. module is in one place and the pro- am working on a similar problem, and grammer won't have to thumb through the approach in the article appears to be Carroll Perkins several pages to read the code for a single more complex than necessary. TO + TL POB 333 module. Having experienced "modules" and TO + TR describe a unique point in Pilot Mountain NC 27041 running as long as 10 to 15 pages, the plane. Only if human interaction heartily agree with this philosophy. with this data were intended would it be SIZING UP In professional programming instal- necessary to translate this to O and TO. MODULAR PROGRAMMING lations, this idea has frequently been An array in memory could map the translated into a local standard of about plane, or decision points could be established and checked against current I enjoyed the "Top -Down Modular 50 lines of code, since this is the number Programming" by Albert D Hearn in of lines which are printed on an 8.5 by values. We must be careful to avoid lim- the July 1978 BYTE, page 32. I thought 11 inch (21.59 by 27.94 cm) page iting the robot to human perceptions. he did a good job of explaining the sub- coming out of a line printer (allowing

ject. While I realize that he was pur- for headers, footers, etc). For the John Gledhill 678 Washington Av posely trying to simplify matters, I do personal computer enthusiast, however, #4 take exception to his comment that a this limit might be more conveniently Yuba City CA 95991 module should be no more than 50 lines set at 24, 32 or 40 lines -the size of the long. video display. CIARCIA'S CIRCUIT CELLAR The concepts of structured pro- For many more complex problems, gramming are intended as guidelines, it is possible that a significant module I am not one for writing to a maga- not as the dogma a programmer's cannot be constructed in 24 lines. This for zine, but your article "Let Your Fingers religion. All of the better known pro- is no problem -just make the modules Do the Talking" (August 1978 BYTE, ponents of the methodology stress this longer. The point is to try to restrict the page 156, and September 1978 BYTE, point, along with the idea that you must module size to a length which enhances page 94) was right on! I read magazines approach the study of structured pro- the programmer's ability to understand and use the ideas and never let editors gramming with your eyes open, making the code. know. I sometimes write the authors. your own evaluation. In this light let us Mr Ciarcia's article was just the best explore the 50 line limit. James Fleming idea for a teacher like me. One of the bases for breaking a pro- 2220 Sims Dr I have been trying to get such an idea gram up into modules is so that a com- Columbus IN 47201 and equipment for my kids in my classroom. This article has helped me take one more step toward my ideal computer learning system for my kids. The touch Announcing .. . panel is a great help for younger kids. Thanks! SMALL BUSINESS COMPUTERS Magazine I will be busy building the hardware and developing the software. I can't The magazine for users and potential users of wait for the next article. Tell Steve to small business computer products and services keep the software coming and tell him what a great contribution he has made.

The monthly magazine for businessmen in the process of purchasing or installing their first corn - I can't wait to see my kids' reaction. puters.

The practical how -to publication written in non -technical language and stressing business applica- Harold R Whitlock tions for small computer systems. Each monthly issue includes: 616 2nd St FEATURE SURVEY REPORTS: Such as, Software Packages for Small Business Applications, White Bear Lake MN 55110 Small Maru /actunng Systems. lnuentory Control Systems, Microcomputer Business Appliactions, and so on. A QUESTION OF PATENTS APPLICATION STORIES: Real-life examples of computer applications in the small business environment - capabilities, benefits, what to watch for, and much more of direct interest to the small I read with interest the articles en- businessman. titled "Let Your Fingers Do the COMPUTER PROFILES IDEAS AND INNOVATIONS INFORMATIVE ADS Talking," as they relate to a noncontact touch scanner or panel. As you are SPECIAL CHARTER SUBSCRIPTION Receive the next 12 issues of Small Business aware, the University of Illinois has two 12 issues @ 50% off Computer Magazine for just $9... 5171.off the patents covering the touch panel de- cover price scribed in the article. They are US patent numbers 3,775,560 and 3,860,764. My Mail the coupon today to: SMALL BUSINESS COMPUTERS Magazine company represents the University of 33 Watchung Plaza Montclair, NJ 07042 Illinois Foundation in the licensing of MIIMMINIMINIUMEMENIEUMNIMENNIMENUIIMM these patents. SMALL BUSINESS COMPUTERS Magazine 33 Watchung Plaza Montclair, NJ 07042 While we have no objection to your description how build the touch YES. Enter my charter subscription at the 1,: price cost of $9 for 12 monthly issues. of to panel, I would appreciate your taking Check enclosed. BM me. appropriate steps to notify BYTE readers that, if they desire to build the Name touch panels commercially, they will Organization need a license under our patents. These patents have already been Address licensed to several companies in the US City/State Zip and their foreign counterparts licensed INIMINIMENIMMIMMIMIMEMIMEMINIIMMENNIMINNIMEMINIIM abroad. We are willing to provide licens-

158 December 1978 ()BYTE Publications Inc Circle 328 on inquiry card. ing terms and conditions to interested feature. I just liked to go in after work cessing was done in analog. A degree of commercial entities. and play Star Trek or Empire against differential comparison was incor- Thank you for your consideration. other people on the system throughout porated, to provide for the variableness the country. of fundamental pitch in each speaker. A Sidney Alpert The design illustrated in BYTE was Template matching was used, with a University Patents Inc done from scratch and any resemblance great deal of "cut- and -try" programming 2777 Summer St to Plato is purely coincidental. I just effort. And if Mr Georgiou thinks the Stamford CT 06905 got an idea for it one Friday afternoon Bell Labs version of 1952 was "gro- and brought the completed unit into tesque," he should have seen this one, Steve Ciarcia replies: the office Monday morning. built from old television sets and record players. While I am personally aware of Although the machine displayed journalistic freedoms with regard to VOICING AN OPINION about a 90 percent recognition rate for patents, many readers may not be. Your my voice (it had obviously been pro- statement is well taken. It should be Congratulations to Bill Georgiou for his excellent primer on speech recog- grammed that way), I was constantly further noted that the University of surprised during public demonstrations nition in June 1978 BYTE ( "Give an Ear Illinois patents appear to cover the how would react correctly to a to Your Computer," page 56). This often it scanning principle and not the design "stranger's" voice. With a practice, wide -ranging and complex topic was little circuitry. even a feminine voice could speak the presented in a most understandable word "open" and see my little solenoid form, yet did not sacrifice excessive PLATO AND THE TOUCH PANEL detail. lock snap back. The article has rekindled my interest As Mr Georgiou stated, voice recog- I lead a double life: during the night in the field, and I shall be looking for- nition has a rather long history, and has I make up little things for my own ward to implementation with my micro- intrigued avid experimenters such as Apple, but during the day I become a processor now. myself for some time. Back in 1965, I rising young training executive of the designed and built a demonstration unit CDC Plato terminal. F Wallace capable of differentiating ten different And that's why Steve Ciarcia's article Burroughs Business Machines Ltd words or short phrases, and activating on touch input units brought me up with POB 861 one of ten relays upon completion of a start - because his touch panel is Winnipeg, Manitoba analysis. The project was awarded a first nearly identical to the touch panels CANADA R3C 2P7 prize at the Canada -Wide Science Fair put on the first Plato terminals! I'm that year. taking about the original Magnavox The implementation was not unlike CALLING ALL COMPUTERS terminals that brought Plato out of the figure 12 in the article, an automatic lab in Illinois and into the world. Those gain control stage followed by multiple I got quite a zing out of Donald terminals, just like Steve's monitor, bandpass filters, except that all pro- Newcomb's letter on the evils of radio had a picture frame around them with 32 LEDs and 32 phototransistors. In fact, there are only minor differences between them and Steve's design except for the aspect ratio - Plato terminals have square screens. The Plato panels even had a built -in circuit that triggered the 0.1 second beep Steve mentioned in his article. One minor difference was that Plato panels had the LEDs on the top and the phototransistors on the bottom. Steve's method is better - the old touch panels would fail regularly whenever the sun shone on them at the wrong angle. Those old panels are obsolete now. TURN YOUR COMPUTER Both CDC and the other Plato terminal INTO A TEACHING MACHINE maker are using different designs, under direct control from an internal micro- The staff at Program Design did not learn processor. But there are still plenty of about educational technology from a book - the old Magnavox boxes out there, in we wrote the book! We have been innovators in schools and colleges across the country. such teaching materials as programmed instruc- In fact, three microprocessor systems tion and multimedia presentations. We also belong

that I know of display output through to that minority in education who actually test ma- a gutted and rewired Magnavox box, terials to see that people can learn from them. bought on the "orange and black Now Program Design brings this experience to the personal market." (named for the color of the computer field. PDI is developing a line of educational and old plasma screens, you know.) game programs for the whole family -from preschool child to adults. Silas S Warner 8 Charles Plaza Program Design educational software uses the computer's full teaching Baltimore MD 21201 potential in exciting and effective ways. Programs are simple to use and memory efficient, and most important ... they teach! Steve Ciarcia replies: TAPES NOW AVAILABLE FOR THE TRS -80, PET. APPLE Il Thank you for the vote of confidence. It may interest you to know that SAMPLE OUR SOFTWARE FOR$2.00. Send us$2.00, your name, address, and I worked for Control Data Corporation type of computer, and we'll send you a tape for your computer with actual samples of for three years as a process control our programs. engineering consultant. During that time Or circle our number on the reply card for a printed catalog. I became familiar with Plato, but never Department 200 PROGRAM DESIGN, INC. 11 IDAR COURT GREENWICH, CONN 06830 have, to this day, used the touch input

December 1978 ID BYTE Publications Inc 159 communications between computers, having just read the DOC's (the Canadian FCC) proposals on the "Packet Radio Service." Welcome to the 19th century, Mr Newcomb! 65. The DOC is proposing not 1 MHz, AIM but the entire amateur radio 220 MHz band and very likely will finalize at 220 -221 MHz, leaving room for a communicator class or GRS (CB) service in the remaining 4 MHz. Our FCC, which Only $375. works very closely with the DOC, is thinking along the same lines. Unquestionably, we'll have radio Get a head start with communications between computers within the next year or two. I, for one, computers the easy, inexpensive am extremely excited by the fantastic possibilities, and am already working on way with Rockwell's AIM 65. suitable equipment. I'd appreciate hearing from others working along the For learning, designing, work or just fun, the R6500 same lines. Advanced Interactive Microcomputer (AIM 65) Donad L Stoner W6TNS /7 offers features you won't find on other comparably John Hancock Bldg priced systems. Mercer Island WA 98040

Alphanumeric 20- Column Thermal IDEAS NEEDED FOR Printer for Hard Copy Listing PROJECT TO AID DISABLED

Alphanumeric 20- Character The Spain Rehabilitation Center at Display the University of Alabama Medical Center has a project underway to Dual Cassette, TTY and demonstrate both the utility and General- Purpose I /Os economic feasibility of the new generation of personal computers for use by R6502 NMOS Micro- the severely disabled. The program- processor mability of the computer will allow it to serve as a general purpose appliance to Read 1K Byte /Write be used as an aid to communication and RAM Memory education as well as for environmental System Expansion Bus control and entertainment. This system, as currently envisioned, Connector will consist of a microcomputer; an on PROM line storage device for programs and /ROM and RAM Expansion Sockets data; two television monitors for user Advanced Interactive Monitor Firmware feedback and information display; a printing device for typed output; a Big, Terminal -Style Keyboard speech recognition device for vocal input of commands, data, and text; a power Optional Two -Pass, Symbolic Assembler and line controller for environmental con- BASIC Interpreter trol; and a telephone dialing and answering device. We are attempting to select components which are widely AIM 65 is available from your local Hamilton /Avnet distributed and serviced as well as being distributor or send the coupon below to: plug compatible and economically Microelectronic Devices, Rockwell International, priced. P.O. Box 3669, Anaheim, CA 92803 or phone Programs will be written or pur- (714) 632 -3729. chased to perform specific functions in each of the four general areas mentioned above. However, we would be very inter- IGET ME STARTED! ested in receiving ideas from your Send me more information on AIM 65. readers, particularly those who are Have someone phone me at disabled, those who have disabled friends or relatives, and those who have personal Name computers and would like to develop hardware or software for the system on Address their own, regarding specific functions which they would like to see developed and which could be accommodated by the proposed microcomputer system. We are looking forward to receiving input from anyone who may be interested in this project. Op Rockwell International Charles Healey where science gets down to business Spain Rehabilitation Center UAB University Sta Birmingham AL 35294

160 December 19780 BYTE Publications Inc Circle 313 on inquiry card. Other BOMB comments about the MAXIMIZE I3YT[' Bits August issue include: YOUR MICRO! Best BYTE I have read in o 8080/Z80 System Software long time. Please devote more dis- Purchasing a microcomputer system, even at cussion to Pascal. The language in today's low prices, is a significant investment. its beauty, compactness and read- Pascal for Computer Club Members And to utilize that investment to its full extent ability is worth talking about. requires a solid base in system software. Don't Would to know more The UCSD Pascal Project has an- like about just accept what comes with your hardware ... the extensions being discussed for nounced a special offer for bona fide there's a better alternative! the language. computer clubs. The UCSD Pascal soft- OPUS /ONE: Business -oriented, block- struc- ware, which normally sells for $200, The article by Weems ( "De- tured high-level language. Includes such will be made available to club members signing Structured Programs ") capabilities as extended arithmetic precision at a sustantial discount if the club assists (up to 55 digits), multi -character variable was easy to comprehend and in the copying and production costs for names, and easy to use string operations. delivered o valuable message. disseminating the software. For more Includes a built -in DOS with random access information, computer clubs should files. This was one of your best contact Tracy Barrett, CO 21, UCSD, OPUS /ONE $99.00 issues. I having related articles La Jolla CA 92093. like in one issue. OPUS /TWO: Extends the capabilities of OPUS /ONE with such features as error trap- To be fair, not all the comments were ping, machine code and OPUS subroutine Attention: HAL 9000 Owners as positive as the last three. The follow- calls, overlays, and more disc file commands. ing BOMB card was also received for the OPUS/TWO $195.00 We have just received word of an month of August: important new book: Programming FORTE: An OPUS run -only system monitor, Instructions for the HAL 9000 Com- perfect for end -user installations. Runs all puter, revised edition. The new edition OPUS Language programs. of the HAL 9000 handbook has been BOMB: avit'e 0.0".. 7aoi*o, 71oa alu FORTE $60.00 updated to incorporate improvements S.O.S.: (Single-user OperatingSystem) A full- suggested by this versatile machine's .CAI q r function DOS which includes OPUS /THREE, users. In the manu- n.a.tw.r. surviving particular, ,..7rw.~..uw.ÓOr. r..x.,,... a text editor (TEXTED), an assembler facturers suggest that priority be given tout Ratini (ASSEMBL), and a package of useful system Mid* to the retrofitting of small explosive I Mambo Poo For Goad Vert Good Excellent Wool utility programs. charges at strategic points in the central 7 10 5.0 S $385.00 memory unit. (fiv 4]] 10 7 10 10 TEMPOS: The ultimate microcomputer Authorized by 1á system software package. A multi- user /multi- 10 tasking DOS which will handle up to 7 Arthur C Clarke 10 b interrupt- driven terminals simultaneously, in a Chief Semantic Controls Engineer m 10 11 7 10 true time -sharing environment. Includes Colombo SRI LANKA 171 4 7 10 1] 7 10 OPUS /THREE, TEXTED, ASSEMBL, and 14 7 10 7 10 many utility programs. Some BOMB Reflections r.1 o 7 10 TEMPOS $785.00 ; 10 it 10 All packages are upward -compatible. That is, Occasionally we like to share some of t.7D; 10 programs and data developed under the unfettered comments, pro and con, comae u Tits riff rf TNí OPUS may be run at any higher level, up that arrive monthly on the BOMB cards, Arti.* N.AG 'r you tar. `1.144144/ /ONE to and including TEMPOS. our system for reader response through a /r fNv+,. 4.41r k. r«. 6.A'.ere.e/,ro,( rift rtet Ff postacard at the back of the magazine. (l Standard device drivers are available for many /o j1>,1, t c 4,5 t aY or The following BOMB card came from /VI .P.lTi re common peripherals; all packages include an anonymous Pascal enthusiast: System Generation capability, allowing the user to interactively add drivers for any I/O We have been suitably chastened. device, including disc drives. BOMB: BYTE'. loo 4101 This is the first time we have been ac- Like to know more? Circle the inquiry number cused of not being subjective enough, below or contact your dealer for your free and we will attempt to examine the pro- copy of our system software brochure! For blem as subjectively as possible....CM complete information, order your user's

Rating manual now, and we'll apply the price toward Incremental Motion Control Symposium purchase of the software. Please add $1.50 per For 7b Goad Very Good Excellent Wool m 17 Issues a Call Papers 6 6 7 (L for manual (set) for shipping/handling within the . , f U.S. (Master Charge and VISA accepted). The Eighth Annual Symposium on OPUS User's Manual $12.50 7 Incremental Motion Control Systems S.O.S. Set (inc. OPUS Manual) $20.00 i and Devices will be held at the Ramada TEMPOS Set (incl. OPUS Manual) $20.00 7 7- Inn, Urbana IL, May 21 thru 24 1979. 7 Dealer & O,E,M. inquiries invited. A call for papers has been issued by 41 7 Prof B C Kuo, director of the sym- ] , 7 16 7 posium, which is sponsored by the ! ,70 ADMINISTTIVE 17 Incremental Motion Control Systems :.0 :» la 7 10 Society, in cooperation with the Univer- SYS EMS .7 : sity of Illinois, Dept of Electrical Engi- Comme ts neering, and Warner Electric Brake =INC. and Clutch Company of Beloit WI. Do The symposium will encompass a broad area with sessions devoted to 1642 S. Parker Road, Suite 300 tutorial papers as well as original con- Denver, Colorado 80231 3 IA al (ff-A4 tributions, covering step motors, (303) 755 -9694 Circle 2 on inquiry card.

December 1978 ©BYTE Publications Inc 161 Circle 33 on inquiry card.

We've got an exciting ground floor opportunity for you to participate in the incredibly fast- growing retail personal computer business. We're Byte Industries. Incorporated?' and we're ufle,ing individual Byte Shop"' franchises, nationwide. Here's your chance to share in the expanding retail personal computer business!

AS A BYTE SHOP YOU GET: The nationally recognized Byte Shop trademark. A broad, full -line inventory of small- business and personal computer products National and regional advertising support. Comprehensive technical and business management training, and on -going advisory services. You Are What You Eat Aid in local site selection, and professionally designed store interiors. Exclusive. protected territories. machine tool control systems, computer metals, mining and metallurgy, power, To qualify, you should have an interest controls, linear and AC /DC motors, process measurement and control, stan- in computers, and a desire and ability clutch -brake devices and systems, and dards and practices, telemetry, test to operate your own business. Retail related incremental motion control measurement, water and wastewater, experience and a sales background at applications. Exhibit space will be avail- pulp and paper, and biomedical instru- management level is a plus. A theoretical or working knowledge of computer able. mentation. Paper topics should intro- technology is helpful. Investment is The call for papers, both theoretical duce or explain techniques or inno- roughly $100.000 with an initial equity and practical, related to incremental vations in instrumentation and control contribution of at least 540.000. motion control systems and devices, systems design, testing, operation and requests authors to submit a summary of maintenance. The papers may be either If you've got what it takes, then you're about 500 words by January 1. Final theoretical in nature or application ready for your own Byte ShopJM manuscripts will be due around mid oriented. The deadline for unsolicited Write or call Dave Pava, our franchise March. Send all summaries and inquiries abstracts is February 5 1979. The appro- development manager now. to Dr B C Kuo, POB 2772, Station A, priate forms should be requested from: Champaign IL 61820, phone (217) ISA /79, Instrument Society of America, 333 -4341. 400 Stanwix St, Pittsburgh PA 15222.

A Call for Papers 40873.98000 American Management Association The Instrument Society of America Offers Courses for EDP and NonEDP has issued a call for papers for its 1979 Professionals conference and exhibit, ISA /79. The BYte In 0,TVW. conference will take place at the O'Hare The American Management Asso- Exposition Center in Chicago IL, from ciation's Information Systems and Tech- Yes. I m interested in a Byte Shop' Franchise Please send me your Franchise October 22 through 25 1979. The nology Division is offering courses for Information packet today. conference theme, Instrumentation for both the electronic data processing Name Energy Alternatives, will emphasize (EDP) and nonEDP professional Address current practices in instrumentation managers. A sampling of the courses design and implementation. Papers are offered include: systems analysis and City being sought in the following areas: design computer security, minicom- State Zip analysis, automatic control, chemicals puters, distributed data processing, Phone_ and petroleum, cryogenics, data handling fundamentals of EDP, office auto- Byte Industries. Incorporated and computation, education and train- mation, EDP applications to human 930 West Maude ing, food, glass and ceramics, main- resources and much more. The courses CA 94086 Sunnyvale tenance, management, marine sciences, run through March 1979. A brochure (408 739-8000 OB1

162 De,r "her 1978 BY TE Publications Inc HOBBYISTS! ENGINEERS! TECHNICIANS! STUDENTS! describing these courses is available from Write and run machine language programs at home, display video the American Management Association, graphics on your TV set and design microprocessor circuits -the 135 W 50th St, New York NY 10020. very first night -even if you've never used a computer before! Addendum ELF II featuring RCA COSMAC ElF II by microprocessor! In the September 1978 BYTE we NETRONICS mini- COMPUTER $9995 published a write -up in the "What's As luttrsd as FORTRAN and BASIC must be translated into machine language before a computer can understand them. With ELF in POPIAAR New ?" section on an assembly language II you build a solid foundation in computers so you'll really development system for 8080 and Z -80 EILCTRONCS know what you're doing, no matter how complicated things get. microcomputers (page 198). We would Shoal with Video output also makes ELF II unique among computers like to pass along some additional optimal Its Nssoq Boasts, selling for such a low price. Attached to your TV set, ELF I I CIAO BOARD "' I Kiwis Board. becomes a fabulous home entertainment center. It's capable of information, which we have just re- providing endless hours of fun for both adults and children of ceived: the PDS development system is all ages! ELF II can create graphics, alphanumeric displays and fantastic video games. available for $99 and is operational on No additional hardware is required to connect ELF I I to any Z -80, 8080, and 8085 computer your TV's video input. If you prefer to connect ELF II to your antenna terminals instead, simply usea low cost RF modulator using the North Star or Micropolis (to order one, see coupon below). Model II disk units. Contact Allen ELF 11's 5 -card expansion bus (connectors not included) allows you to expand ELF II as your needs forpower grows. If Stop abou and get on Ashley, 395 Sierra Madre Villa, Pasadena reading computers your hands une!With you're an engineer or hobbiest, you can also use ELF II as a ELF II and our new by Tom Pittman, you can CA 91107. Short Course counter, alarm, lock, thermostat, timer or telephone dialer, or master computers in no time at all! ELF II demonstrates all 91 for countless other applications. commands an RCA 1802 can execute and the Short Course quickly teaches you how to use each of the 1802's capabilities. ELF lI Explodes Into A Giant! ELF ll's video output lets you display an alphanumeric Thanks to ongoing work by RCA and Netronics, ELF II readout or graphics on any TV screen or video monitor plus add -ons are among the most advanced anywhere. Plug in the enjoy the latest video games, including an exciting new GIANT BOARDand you can record and playback programs, target /missile gun game that was specifically developed for edit and debug programs, communicate with remote devices ELF II. and make things happen in the outside world. Add Kluge Board But that's not all. Once you've mastered computer funda- to get ELF II to solve special problems such as operating a mentals, ELF II can give you POWER with add-ons that are more complex alarm system or controlling a printing press. among the most advanced found anywhere. No wonder I EEE Add 4k RAM board and you can write longer programs, store 1313g$ chapters plus hundreds of universities and major corporations more information and solve more sophisticated problems. I3YT['$ have chosen the ELF II to introduce their students and per - Expanded, ELF II is perfect for engineering, business, sonnel to microprocessor computing! industrial, scientific and personal finance applications. No other small computer anywhere near ELF II's low price is Far Learn The Skill That May Soon Be backed by such an extensive research and development pro- MorelmportantThan Your College Degree! gram. The ability to use a computer may soon be more important to The ELF -BUG x Monitor is an extremely recent break- your earning power than a college degree. Without a knowl- through that lets you debug programs with lightening speed Chess Bug edge of computers, you are always at the mercy of others when because the key to debugging is to know what's inside the it comes to solving highly complex business, engineering, in- registers of the microprocessor and, instead of single stepping dustrial and scientific problems. People who understand com- through your program, the ELF-BUG"' Monitor, utilizing Due to an oversight on our part, a puters can command MONEY and to get in on the action, you break points, lets you display the entire contents of the regis- number of errors appeared in the must learn computers. Otherwise you'll be left behind. ters on your TV screen at any point in your program.You find out immediately what's going on and can make any necessary October 1978 "In This BYTE" entry ELF II Is The F -A-S-T Way To Learn Computer Fundamentals! changes. Programming is further simplified by displaying 24 bytes of RAM with full address, blinking cursor and auto (page 4) for "Creating a Chessplayer" computer background is now, Regardless of how minimal your scrolling. A must for serious programmers! to program a in almost no time at all. by Peter W Frey and Larry Atkin. The you can learn computer Netronics will soon be introducing the ELF II Color That's because Netronics has developed a special Short Graphics & Music System -more breakthroughs that ELF I I introduction implies that Peter Frey is And Programming in Course on Microprocessor Computer owners will be the first to enjoy! one of the creators of Chess 4.6. This is non -technical language that leads you through every one of t he RCA COSMAC I802's capabilities so you'll understand Now BASIC Makes Programming ELF II Even Easier! not true. The program was written by everything ELF II can do...and how to get ELF 11 to do it! Like all computers, ELF II understands only "machine Larry Atkin and David Slate. Peter Frey All 91 commands that an 1802 can execute are explained to language -the language computers use to talk to each other. you, step -by -step. The text, written for Netronics by Tom But, to make life easier for you, we've developed an ELF II was also erroneously referred as to Pittman, is a tremendous advance over every other program- 'IlnyBASIC. It talks to ELF I I in machinelanguageforyou so "David" Frey, and Larry Atkin as Larry ming book in print. that you can program ELF II with simple words that can be Keyed specifically to the ELF II, it's loaded with "hands typed out on a keyboard such as PRINT, RUN and LOAD. "Atkins." We sincerely apologize to all on" illustrations. When you're finished, ELF II and the 1802 Do... will no longer hold any mysteries to you. "Ask Now What Your Computer Can concerned for these errors. Can It Do For YOU!" In fact, not only will you beable to use a personal computer But What creatively, you'll also be able to read magazines such as Don't be trapped into buying a dinosaur simply because you Address Change BYTE...INTERFACE AGE...POPULAR ELEC- can afford it and it's big. ELF II is more useful and more fun TRONICS and PERSONAL COMPUTING and under- than "big name" computers that cost a lot more money. stand the articles. With ELF II, you learn to write and run your own programs. You're never reduced to being a mere keypunch operator, In the "What's New ?" section of If you work with large computers, ELF II and our short Course will help you to widerstand what makes them tick. working blindly with someone else's predeveloped software. November 1978 BYTE we reported on No matter what your specialty is, owning a computer which A Dynamite Package For Just $99.951 you really know how to use is sure to make you a leader. ELF a new product from TSA Software (page With ELF II, you learn to use machine language-the funda- II is the fastest way there is to get into computers. Order from 216). This company has notified us of a mental language of al computers. Higher level languages such the coupon below! change of address. Their new address --SEND TODAY! - 1 NOW AVAILABLE FOR ELF N- Deluxe metal cabinet for ASCII Netronics R&D Ltd., Dept. 0000 is: 39 Williams Dr, Monroe CT 06468. O Tom Pittman's Short Course On Mi- Keyboard, $19.95 plus $2.50 p &h. 333 Litchfield Road, Phone croprocessor 5 Computer Program M- ELF II Tiny BASIC on cassette New Milford, CT 06776 (203) 354 -9375 ing teaches you just about everything tape. Commands include SAVE, Yes! I want to run programs at home and Tilt! about II or any LOAD, ±, x, +, ( ), 26 variables A -Z, there is to know ELF have enclosed: 599.95 plus $3 postage Written in non- LET, IF INPUT, PRINT, RCA 1802 computer. /THEN, s handling for RCA COSMAC ELF II kit, language, it's a learning TO, GO SUB, RETURN, END, technical GO for power supply (required), Some errors crept into the Pinball breakthrough for engineers and laymen REM, CLEAR, LIST, RUN, PLOT. $4.95 $5 for RCA 1802 User's Manual, $5 alike. $5.00 postpaid! PEEK, POKE. Comes fully docu- Wizard program that appeared in my for Short Course on Microprocessor S Deluxe metal cabinet with plexiglas mented and includes alphanumeric -67 HP -97: Hewlett - Computer Programming. article "The HP and dust cover for ELF II, $29.95 plus generator required to display al- your I want mine wired and tested with Packard's Personal Computers" (June $2.50 p &h. phanumeric charactersdirectlyon additional hard- power supply, RCA 1802 User's Manual ELF II connects to the video input TV screen without page code in a andShortCourse Included for just $149.95 1978 BYTE, 112). The of your TV set. If you prefer to use ware. Also plays tick -tack -toe plus that uses ELF II's hex plus $3 WI step 69 of listing 1 (page 114) should your antenna terminals, order RF drawing game I am also enclosing payment (including Modulator, $8.95 postpaid. heyboard as ajoystick. 4k memory re- read "35 00," not "36 00 "; the key postage d handling) for the items checked GIANT BOARD° kit with cassette quired. $14.95 postpaid. Short Course on 71ny at the left. entry is correct, however. Also, step 189 I /O, RS 232- C(1 -f'Y I/O. 8 -bit P I /O, Tom Pittman's Total Enclosed (Conn. res. add tax) decoders for 14 separate I/O instruc- BASIC for ELF I I, $5 postpaid. (page 115) should read "RCL B 36 12," $ Check here if tions and a system monitor /editor, Expansion Power Supply (required you are enclosing Money Order or Cashier's not "RCL 6 36 06," and step 139 should $39.95 plus $2 p &h. when adding 4k RAM). $34.95 plus $2 Check to expedite shipment. Kluge (Prototype) Board accepts up p &h. read LBL 0 21 00 instead of LBL 0 21 USE YOUR VISA Master Charge to 36 IC's. $17.00 plus $1 p &h. ELF-BUG `S Deluxe System Monitor (Interbank 16. 4k Static RAM kit. Addressable to on cassette tape. Allows displaying the #- - - on your TV at # My apologies to any readers who any 4k page to 64k. $89.95 plus $3 p &h. contents of all registers Account any in your program. Also dis- Gold plated 86 -pin connectors (one point Signature Exp Date might have experienced difficulties in plays 24 bytes of memory with full ad- required for each plug -in board). $5.70 PHONE ORDERS ACCEPTED (203) 354-9375 using the program. postpaid. dresses, blinking cursor and auto scroll- for serious program. Print Professional ASCII Keyboard kit ing. A must the mer! $14.95 postpaid. Name with 128 ASCII upper/lower case set, Craig A Pierce 96 printable characters, onboard regu- Coming Soon: A -D, D -A Converter, Address lator, parity, logic Light Pen, Controller Board, Color 2529 S Home Av selection and choice City of 4 handshaking signals to mate with Graphics & Music System...and more! Brewyn IL 60402 almost any computer. $64.95 plus $2 State Zip Call or write for wired prices! L&h. - DEALER INOUIRIESINVITED Circle 280 on inquiry card. December 1978 ©BYTE Publications Inc 163 be discussed include floating point mathematics, lookup tables, number base conversion, interrupt programming, searching and sorting. Contact Dr Linda Leffel, Donaldson Brown Center for Continuing Education, Virginia Poly- technic Institute and State University, Evert U0e08 Blacksburg VA 24061, (703) 951 -5421.

December 6 -8, Data Processing Oper- ations Management, Washington DC. In order to gain optimum coverage of December 4 -6, 1978 Annual Conference This 3 day seminar will emphasize the your organization's computer confer- of the Association for Computing management skill and techniques appli- ences, seminars, workshops, courses, etc, Machinery, Sheraton Park Hotel, cable to the data processing operations notice should reach our office at least Washington DC. Contact Dr Richard function. Contact Phillip M Nowlen, three months in advance of the date of Austing, Dept of Computer Science, director, Center for Continuing Edu- the event. Entries should be sent to: cation, The University of Chicago, Event Queue, BYTE Publications, 70 University of Maryland, College Park Main St, Peterborough NH 03458. MD 20742, (301) 454 -2004. 1307 E 60th St, Chicago IL 60637.

December 3 -5, Ninth North American December 4 -6, Minicomputers and Dis- December 12 -14, Midcon /78, Dallas Computer Chess Championship, tributed Processing, Atlanta GA. This Convention Center, High Technology Sheraton Park Hotel, Washington DC. 3 day seminar will examine the uses, electronics show and convention. The 1978 annual meeting of the Asso- economics, programming and implemen- Contact Electronic Conventions Inc, ciation for Computing Machinery will be tation of minicomputers. Contact Philip El Segundo CA, (800) 421 -6816 (toll the site of this chess championship. This M Kowlen, director, Center for Con- free). will be a 4 round Swiss style tournament tinuing Education, The University of with participants restricted to com- Chicago, 1307 E 60th St, Chicago IL December 13, Computer Networking puters. Two rounds will be played on 60637. Symposium. Sponsored by the IEEE December 3 (1 PM and 7:30 PM), one Computer Society's Technical Com- on Monday (7:30 PM) and the last December 4 -8, Microcomputer Software mittee on Computer Communications round on Tuesday (7:30 PM). Deadline Design, Virginia Polytechnic Institute and the Institute for Computer Sciences for entries is October 20. Contact and State University, Blacksburg VA. and Technology of the National Bureau Prof M M Newborn, School of Computer This workshop will develop assembly of Standards. This symposium will high- Science, McGill University, Montreal language programming skill for 8080 and light papers of practical and research Quebec H3A 2K6, CANADA. 8085 based microcomputers. Topics to experiences concerning both computer and communication networks. Contact Dr George Cowan, Computer Sciences Corp, 6565 Arlington Blvd, Falls Church Content- Addressable Memory VA 22046. December 13 -15, Distributed Mini- for the S -100 bus computer Networks, Executive Tower Inn, Denver CO. This seminar will Discussed and dreamed about by Adds 17 associative memory func- address the minicomputer from the computer scientists for years, Con- tions to instruction set of Z -80 or 8080. viewpoint of the distributed network tent- Addressable Memory (CAM) Applications: user. The structure and management of a is now here at an affordable price. Pattern Recognition Information large data base and software problems CAMs have been so costly to build Retrieval Compiling & Interpreting with the trade -offs of languages utilized, that few have actually been pro- Natural Language Processing hardware types, input and output duced. Now Semionics has devel- Code Compression Artificial Intel- options, device controllers, system oped a simplified design, lowering ligence failure and recovery, sample application the cost by two orders of magnitude. Price: $325 case studies and the economics of mini- This new memory is called Recogni- computer applications will be covered 4K firmware package of REM tion Memory (REM), the in depth. Contact The Institute for since (like routines: $80 human brain) it can recognize words, Professional Education, Suite 601, 1901 patterns, etc. N Fort Myer Dr, Arlington VA 22209, Adding a REM board to an ordinary Z SEMIONICS (703) 527 -8700. microcomputer converts it into a very 41 Tunnel Road Berkeley CA 94705 December 18 -21, Microcomputer Data powerful machine known as a Con- (415) 548 -2400 tent- Addressable Parallel Processor Acquisition, Instrumentation and Measurement Systems, Virginia Poly- (CAPP). technic Institute and State University. Features: Course to be given by the authors of the 4K bytes per board Bugbooks. Contact Dr Linda Leffel, Static -no refresh needed Donaldson Brown Center for Continuing Education, Virginia Polytechnic Institute Can be used as ordinary RAM and State University, Blacksburg VA or as CAM 24061, (703) 951 -5421. RAM access time: 200 ns 4 CAM access time: µs January 8 -12, Structured Programming Multiwrite- writing into multiple and Software Engineering, George locations with one instruction Washington University, Washington DC. Masking -for individual bit This course is designed for experienced access program architects, designers and Multiple REM boards accessed managers. It will provide up to date in parallel technical knowledge of logical expression, analysis and invention for performing and managing software archi-

164 December 1978 © BYTE Publications Inc Circle 323 on inquiry card. tecture, design and production. Presen- tations will cover principles and appli- SELECTOR II cations in structured programming and software engineering. Design workshops A QUERY LANGUAGE with analysis and review sessions will provide actual practice in problem A REPORT WRITER H8 solving. Contact George Washington FILE SYSTEM ISAM University, Continuing Engineering Edu- AN PROGRAMS cation, Washington DC 20052.

GAMES January 15 -17, Minicomputers and Dis- What does SELECTOR Eleven computer games, including Black- tributed Processing, San Francisco. For jack, Hangman, 23 Matches, Tic- Tac -Toe, II do? Well just about Silly Sentence Maker, Poem Writer, Word details, see December 4 -6, Atlanta. Puzzle, Backtalker, Math Quiz, Caricature everything . . . Printer, and Typing Speed Drill, (Stock Nc January 17 -19, Distributed Minicom- 101.1, Cassette, Requires Ext. B.H. Basic Simply define a file Issue 10.01 or 10 02, S10) puter Networks, Ramada Inn, Arlington VA. For details, see December 13 -15, record with item names Denver. and types (money fields PERSONAL FINANCE Includes two programs. Personal Budget January 24-27, International Microcom- or dates, etc.). Pick key provides a personal accounting system and helps reconcile your checkbook. Interest puters /Minicomputers Microprocessors fields. Enter data. calculates simple interest. compound '79 /Japan, Harumi Exhibition Center, interest, and mortgage amortization Tokyo. Contact ISCM, 222 W Adams St, At any time you can schedules. (Stock No. 102 1, Cassette. Chicago IL 60606, (312) 263 -4866. Requires Ext. B.H. Basic, Issue 10.02, S10) select records by key for updating or deletion. Or January 30- February 1, Communication COOK'S HELPER Networks Conference and Exposition, you can select collect- Two programs to help the cook Menu pro- Sheraton Park Hotel, Washington DC. ions of records by the duces nutritious, within -calorie- limits Designed to bring together communi- menus. Shopper makes your trip to the grocery store more enjoyable by arranging cation network users, consultants, ven- data they contain (like your grocery list in the shelf order of your dors and regulatory officials so that all blue -eyed ladies favorite store. prevents backtracking to issues can be discussed and analyzed. look for missed items. (Stock No. 103.1. It is particularly aimed at executives speaking French who Cassette. Requires Ext. B H. Basic, Issue who 10.01 or 10.02. $10) and managers purchase communi- purchased Gizmo 500's cation products and services. Contact The Conference Company, 60 Austin St, in March). You can have MAILING LIST Newton MA 02160. Features programs for the creation, updat- that information dis- ing, sorting, and printing of mailing lists played or summarized and labels. Highly flexible, with provision February 1 -3, Microprocessor Program- forcodingeach entry, sorting on any desired ming Workshop with a Take -Home on your screen or listed field, printing selectively by code. printing Microprocessor, Jefferson Plaza Building. on various sizes and layouts of labels. on your printer properly (Stock No. 104 1, Cassette. Requires Ext. Arlington VA. Sponsored by the IEEE, B.N. Basic. Issue 10.02. $20) this 3 day workshop is intended for the titled, paginated, for- practicing engineer, engineering manager matted, totaled, aver- and programmer. The course objective MAILING LIST -DISK is to provide state the art This disk -based package contains features of information aged, max -ed or min -ed similar to those of the cassette version in order to acquire an understanding ... as you desire. above, plus the addition of a feature that of the place of microprocessors as permits computerized printing of form replacements for wired logic and as SELECTOR II does all of letters to persons on the mailing list. (Stock controllers; to provide the capability of No. 114 1, Diskette, Requires HDOS your fielding, finding, Basic. $30) understanding the design of systems involving microprocessors; and the formatting and fuming All programs are recorded on cassette or to program the Motorola M6800 diskette ready for use with your Heathkit ability for you. All you need do H8 computer. Each package comes com- microprocessor in machine language. All plete with program listings and user in- students will have their own micro- is issue orders. structions. A discount of 10% is given if processor and laboratory equipment. II more than one item is ordered at once. SELECTOR is avail- Price includes shipping to U.S. destina- Contact IEEE Service Center, 2145 tions. Items are in stock for immediate Hoes Ln, Piscataway NJ 08854. able for Microsoft shipment. Extended Disk BASIC February 13 -15, The National Office and CBASIC, on diskette, Exhibition and Conference, Harbour Castle Hilton Convention Center, with user's manual for Toronto Ontario. This 3 day exhibition $255 including 1 year EdProlncorporoted will provide a showplace for approximately 100 exhibitors in the areas of maintenance. Dealer in- 6580 Buckhurst Trail word processing, office computers, Atlanta, GA 30349 quiries gladly accepted. Please send the following: office equipment and furniture. Contact Amount Enclosed Canadian Office magazine, 2 Bloor St W, GAMES @ 510 Suite 2504, Toronto Ontario, CANADA PERSONAL FINANCE @ 510 Micro -Ap COOK'S HELPER @ 510 M4W 3E2, (416) 967 -6200. MAILING LIST @ 520 8939 San Ramon Road MAILING LIST -DISK @ 530 February 14 -16, The IEEE International TOTAL Phila- Dublin, CA 94566 Less 10% Discount if Ordering Solid -State Circuits Conference, Two or More Items delphia PA. Forum for the presentation AMOUNT ENCLOSED S - of new advancements in all aspects of Name solid -state circuits. Contact Lewis Street Addr 301 Almeria Av, POB 343788, City Winner, Gables FL Circle 218 on inquiry card. Slate ZIP Coral 33134.

Circle 113 on inquiry card. December 1978 ©BYTE Publications Inc 165 computers. The membership fee is $10 edition contains reviews of current work per year. For more information, write in the field, a forum for the exchange of Clebs ad to Albert Brunelli at POB 69, Berlin NH information, an ongoing bibliography, 03570. and news about pertinent hardware and NeWSlettePs software. Membership and a subscription Denver Amateur Computer Society to Micro -Psych costs $10 per year. For more information about this newsletter, The Denver Amateur Computer contact Marc D Schwartz, MD, 26 Attention: Robot Enthusiasts Society now has permanent club quar- Trumbull St, New Haven CT 06511. ters and office at 1380 S Santa Fe Dr, The Robotics Newsletter is a month- Denver CO 80223. The club meets the Connecticut Computer Club Welcomes ly periodical for robot enthusiasts on third Wednesday of every month at All Level Hobbyists both the hobby and professional level. 7:30 PM. For further information, It presents timely articles on micro- write to the society's president, Mike The Connecticut Computer Club, computers, batteries, motors, automata Dymtrasz, at the above address or call which is a few years old, consists of an theory, sensory devices, manipulators, (303) 979 -6441. informal group of software and hardware biophysical analogs, robot history, etc. people who meet on a monthly basis to Yearly subscriptions are $8. Contact the The Okaloosa Computer Hobbyist Club exchange ideas. Speakers and demon- International Institute for Robotics, strations are of general group interest. POB 615, Pelahatchie MS 39145. We have been notified that the The club meets the first Thursday of Okaloosa Computer Hobbyist Club has each month at either the Suffield Northern New England Computer been formed in Ft Walton Beach FL. Library or The Computer Store of Society The meetings are held on the second and Windsor Locks. A newsletter is available fourth Tuesday of each month and all to members at a yearly cost of $5. Albert Brunelli has written us that a interested persons and newcomers are Contact Leo Taylor, 18 Ridge Ct W, new computer club has been formed "up welcomed. For more details, write to W Haven CT 06516, (203) 933 -5918. here in the north woods." It is located Loretta R Guske, # 72, 32 Denton Blvd in Berlin NH and is called the Northern NW, Fort Walton Beach FL, (904) Quad City Computer Club New England Computer Society. They 242 -5938. meet the second Thursday of each We have heard from John E Greve, month at 7 PM at the New Hampshire Computers in Mental Health Newsletter president of the Quad City Computer Vocational Technical College, Milan Rd, Club (QC3). The club, devoted to all Berlin. Their aim is to set up an area Micro -Psych is a newsletter for pro- phases of hobbyist computing, meets on that is accessible to loca! people where fessionals interested in the use of com- the first Sunday of each month at 7 PM they can learn about and use small puters in mental health. Each bimonthly at the Rock Island Arsenal classroom # 5, Rock Island IL. The dues are $6 per year, which includes a newsletter. For more information concerning this club, contact John E Greve, 4211 7th Av, Rock Island IL 61201. S -100 BUS COMPATIBLE. The EMM 1104 single card plug -in memory has been field tested and proven in a variety of systems including the Poly 88, Apple 11 Users Group in Portland OR IMSAI, MITS, COMPAL-80, TLD and CREMENCO. 16K BYTES ON A CARD. Convenient plug -in card, fully burned -in, tested and guaranteed by one of The Apple Portland Program Library the industry's largest memory suppliers. NMOS STATIC RAM. The 4K Exchange, or APPLE for short, has been static RAMs have been proven in applications ranging from single chip formed as a users group for owners of memories to IBM 370 add -on systems. They are fast, the Apple II. They are interested in reliable, and no refresh cycle is required. exchanging programs and ideas with See your dealer, or contact us for complete information. EMIR other clubs. Send a self- addressed stamped envelope for an application form to Ken Hoggatt, 9195 SW Elrose S -100 Bus Compatible Memory Ct, Tigard OR 97223.

16K bytes on a card Canadian PET Owners Start Users Group

The Vancouver PET Users Group NMOS static RAM recently held their second meeting. Attendees included 40 owners and 15 PETs. The club format includes a short presentation by a PET owner on programming, or PET hardware news from Commodore and other sources. This is followed by PET patter and program swapping. For more information about this club, write to Richard Leon, Vancouver PET Users Group, POB 35353, Station E, Vancouver British Columbia, CANADA.

TRS -80 Computing

A complimentary copy of TRS -80 Computing has been sent our way. This 32 page first edition is packed with TRS -80 news including articles by a Commercial Memory Products, a Division of Electronic Memories & Magnetics Corp. TRS -80 designer, a Radio Shack repair- 12621 Chadron Avenue Hawthorne. California 90250 Telephone (213) 644 -9881 man, and a couple of programmers; an article on how to install your own 16 K

166 December 1978 © BUTE Publications Inc Circle 132 on inquiry card. The byte integrated circuits and save; a 10 Rothenberg THE END page schematic, and considerably more. The price for 12 issues is $10 and is available from Computer Information OF YOUR Exchange Inc, POB 158, San Luis Rey CA 92068. SYSTEM Chicago Area Computer Hobbyist Exchange Forms User Groups INTEGRATED

In keeping with the club's philosophy of dedication to investigating FINANCIAL the roles and uses of microcomputers and related small size computing devices in the hobbyist field, the Chicago Area SYSTEM Computer Hobbyist Exchange (CACHE) has recently announced the formation of user groups. According to the club's newsletter CACHE Register, the North under Star, SOL and Digital Group user groups are active and going strong. The CP /M, Put this SOROC IQ 120 at the H- 11 /LSI -11 and computer aided in- CP/M* end of your system for fast and struction user groups have formed but silent input/output. are not meeting regularly. There are other groups in the formative stages. $79500* CACHE members meet on the third GENERAL LEDGER Sunday of each month at 1 PM in the Northern Illinois Gas Building, Golf ACCOUNTS RECEIVABLE and Shermer Rds, Glenview IL. Contact Bill Precht, president, POB 52, S Holland ACCOUNTS PAYABLE IL 60473. PAYROLL Attention Minneapolis /St Paul

Apple I I Users INVENTORY CONTROL

We have been notified by Dan Buchler, 13516 Grand Av S, Burnsville MN 55337, that an Apple II users group has been formed in the Minneapolis Easy to use, self -guided. and St Paul area. The purpose of the You don't have to be a CPA! group is to promote the exchange of user Put this T.I. 810 printer at the developed programs and technical infor- end of your system for fast and mation among Apple II users. Help in documenting programs will be offered. reliable hard Price: $500 each -copy output. Contact Dan Buchler for further information. Complete manuals: $8 each $169500* Immediate Delivery Newsletter for Users of Digital Group Equipment Requires only 32K system

BRIDGE (Bidirectional Reflections for the Illumination of Digital Group Requires CBASIC ** Enthusiasts) is an impressive newsletter devoted to helping fellow Digital Group Prepaid or COD only owners over the voids. The cost of membership is $6, which entitles you to Send CP /M serial # with each order six issues of the newsletter. The most recent newsletter contains a couple of articles, items for sale, random bits of Also available: information of interest to Digital Group Put this TELETYPE 43 at the Complete Legal Billing System equipment owners and much more, end of your system for reliable including a letter from BYTE's Steve Only$1995. Manual $8. low -cost input /output. Ciarcia, an occasional contributer. If this newsletter is of interest to you, it can be obtained by writing to the Digital $99900* Group Independent Users Group, POB *plus 2% handling. 316, Woodmere NY 11598. Rothenberg Shipped freight collect. INFORMATION sysTEMS, INC. Rockwell's AIM 65 Users Group 260 Sheridan Avenue An AIM 65 users group is being Palo Alto, CA 94306 formed for Rockwell's computer -on- (415) 324-8850 MICROMAIL BOX 3297 SANTA ANA. CA 92703 I (714) 731 -4338 J a- board. A bimonthly newsletter will be available in January 1979 for $5 per year. Article contributions are welcome. *CP /M is a trademark of Digital Research For Also DIABLO. LEAR /SIEGLER. DEC. more information about this group, * *Add $100 if CBASIC is also needed contact Don Clem, RR #2, Spencerville Write or call for a free catalogue. OH 45887. Circle 328 on inquiry card.

Circle 222 on inquiry card. December 1978 © BYTE Publications Inc 167 A I Halsema 32014 Grenville Ct Partitioned Data Sets Westlake CA 91361

Figure 1: Information ar- SYSTEM VOLUME TABLE VOLUME TRACK SECTOR LIBRARY EMPTY CONTROL rangement for a small OF CONTENTS SERIAL MAP MAP CONTROL BLOCKS partitioned data set. TRACK NUMBER BLOCK

SOURCE LINKAGE ASSEMBLER EDITOR EDITOR FREE OBJECT SEDITR ASSM LEDITR OBJECT OBJECT SPACE CODE CODE CODE

DIRECTORY MEMBER ENTRIES FOR DATA MEMBERS RECORDS

If you have a floppy disk and are having Designing the Partitioned Data Set trouble keeping track of where your programs and data are written on it, this simple Four things are required for definition file organization technique may provide the of a partitioned data set. First, a map for automated management of disk space you defining those areas on the disk that are in need. use (allocated). For this we create a track A partitioned data set (PDS) is a file map that defines each track on the disk with divided (or partitioned) into areas, each one bit. If the bit is set to 1, the corres- About the Author area containing data not related to data in ponding track is free. If the bit is set to 0, other areas. For example, a system library the track is in use. For a disk with 77 tracks, Mr Halsema is project might contain a source editor, assembler a 10 byte track map is sufficient. The posi- leader of a funds transfer and linkage editor. Each of these programs tion of each bit in the map defines the system for a subsidiary of could be stored in a separate partition in a address of its associated track. The first the First National City partitioned data set. The partitioned areas bit in the map defines track 0, the second Bank. At home he owns in which these programs would be stored bit defines track 1, etc. The track map is a SwTPC 6800 with cas- are called members of the data set, so the referenced whenever a data set is allocated sette storage and video partitioned data set just described would or scratched, so the smallest data set possible terminal. contain three members, as in figure 1. would be 1 track in length. Second, we need a sector map to keep track of which sectors are in use and which

are free. As in the track map, we assign 1 bit Volume label 6 bytes in the map to each sector. If our disk has 10 Number of table of contents sectors 1 byte sectors per track, the sector map must be Tracks per volume 1 byte 770 bits in length, so we assign 97 bytes to Sectors per track 1 byte Bytes per sector 2 bytes it. As in the track map, the position of each Track map 10 bytes bit defines the address of the associated Sector map 97 bytes Unused 10 bytes sector. The sector map, table 1, is used when a member is created in or deleted from a data set. (lb) Data set name 6 bytes Third, a control block for defining the Beginning address of data set 2 bytes name and location of the partitioned data Ending address of data set 2 bytes sets is needed. These blocks can immediately Length of logical records in data set 1 byte Length of directory in sectors 1 byte follow the maps, and should contain space Unused 4 bytes for the data set name, starting track address of the data set, length of directory in tracks, Table 1: Possible arrangement for the label record (1a) and data set control and the ending track address of the data set. block (1b) for a partitioned data set. Following this control block are similar

168 December 1978 © BYTE Publications Inc Member name 6 bytes (DISKINIT ` data area address for Start of member 2 bytes \ End of data area address for member 2 bytes I Number of logical records in use 2 bytes Data type of member 1 byte COMMAND Unused 3 bytes OUTPUT READ COMMAND TEXT

Table 2: Format for the directory entry information. MAPT CREATE TRACK MAP control blocks for other data sets and unused (free) control blocks. A free control MAPS is block indicated by the name field being CREATE filled with binary Os. SECTOR MAP The maps and the control blocks can all fit on a single track. This track is called the WRITE FIRST volume table of contents (VTOC) and begins VOLUME TABLE OF CONTENTS SECTOR with the volume label, also known as the volume serial number (VSN). If we want a multitrack volume table of contents, we need to define how many tracks are in the table for use by the access method software. SEEK NEXT SECTOR A byte for a count of the tracks in the volume itself should be included. If our system is to handle different formats and densities it would be wise to include the NO WRITE A ZERO FILLED SECTOR format information in the table of contents. The access method software could then read the count of the number of tracks on the disk and the number of sectors per track MOVE TO FIRST SECTOR OF DATA directly from the table and be able to STORAGE AREA handle several formats without modification. In order to avoid wasting disk space, 16 L byte logical records can be blocked 8 to a 128 byte sector. A single track volume table WRITE ZERO of contents blocked in this way could handle FILLED SECTOR 136 partitioned data sets. The fourth item required for a partitioned data set is a directory for the members in the data set. The SEEK NEXT directory, table 2, begins at the first sector SECTOR of the first track of the actual data storage area. The directory entries are 16 bytes long and packed 8 to a 128 byte sector. Each NO entry contains the name of the member, the starting and ending track and sector addresses of the member, the count of the number of sectors actually used by the member, and Figure 2: Disk initializa- EXIT ) the data type of the member. The data type tion program. may be:

0 : Source data.

1 : Core image object data. Implementation

2 : Relocatable object data. The first program we need is a disk initial- Both source and BASIC programs may be ization routine such as the one in figure 2. stored in a member of data type 0, while The initialization routine creates and empties data type 2 is used as input to a relocating the volume table of contents track and clears loader, linking loader or linkage editor. the data storage area by setting it to O.

Data type 1 is used for storing nonrelocatable The user is required to enter the volume programs. serial number and the beginning and ending Now that the design of the file structure track numbers of the data storage area. The is complete, we can design software that will track and sector maps are created so that the create, manipulate and delete members and bits corresponding to the data storage area data sets. are set to 1 (free space) and all other bits

December 1978 © BYTE Publications Inc 169 (ALLOCATE

COMMAND OUTPUT READ COMMAND TEXT

LOOK SEARCH ON LINE DRIVES FOR PROPER DISK

NO ERROR ) \\ EXIT

SEARCH TABLE OF CONTENTS FOR DATA SET NAME

MEMBER DATA SET

NO YES ¡ ERROR I\ EXIT

SEARCHD SEARCHT SEARCH DIRECTORY SEARCH TRACK FOR MEMBER NAME MAP FOR SPACE

Figure 3: The ALLOCATE routine, used to put a new YES NO file onto the disk and update all pointers to indicate that the file is NO present. SEARCHS SEARCHV SEARCH SECTOR SEARCH VOLUME TABLE MAP FOR FREE OF CONTENTS FOR SPACE EMPTY CONTROL BLOCK

ERROR NO NO ERROR EXIT EXIT

YES

SE ARCH D SET SPACE SEARCH DIRECTORY STATUS "IN USE" FOR EMPTY ENTRY IN TRACK MAP

BLOCK ERROR NO EXIT BUILD CONTROL ( BLOCK

YES

SET DIRECTORY SET SPACE IN SECTOR MAP SECTORS "IN USE" IN USE" IN SECTOR MAP

REWRITE VOLUME REWRITE VOLUME TABLE OF TABLE OF CONTENTS CONTENTS

BUILD SET DATA STORAGE DIRECTORY ENTRY AREA TO ZERO

( EXIT )

170 December 1978 © BYTE Publications Inc Circle 8 on inquiry card. are set to 0 (space used). The volume label, PUT A HANDLE a count of the tracks used by the volume table of contents (permanently set to 1) and ON YOUR TRS 80® Matched set of custom built cases to protect and store your computer. the maps are then written on the first sector Dustproof Durable Vinyl Construction Keyboard of the first track of the disk. All other Convenient Handsome Black Textured Finish, Protective skids Luggage Style Handle Cassette Machne Accessories I sectors of the table of contents track are I INSIDE VIEW set O. Every to binary sector of the data Cm 8/25.00 storage area is also set to O. Initialization -r--3 of the disk is now complete. Once the disk has been initialized, we can allocate data sets on it by using the allocate routine. The allocate routine shown in figure 3 actually consists of two routines: one to allocate data sets, and one to allocate members in a data set. To allocate a data set, the Case A /35.00 Molds ,x Wawa Mona. user enters the volume serial number of the Special! Order A Set disk, the name of the data set to be allocated Save 10% Your Cost $54.00 (six characters maximum), the number of Get Protection For Your sectors to be used for directory, and the TRS 80 Now number of tracks to be devoted to the data Order Yours Today! Made in the USA by Ambico Inc., 101 Horton Ave. Lynbrook, N. Y. 11563 area. Note that the space used for the directory is included in the amount of space r Send Check or Money Order to: Ambico Inc. entered for the data area definition. 101 Horton Avenue Lynbrook, New York 11563 The allocator routine then reads the Case A $35.00 Case B $25.00 volume table of contents track and verifies Set: Case A and B $54.00 that the volume serial number on the disk Send To matches that entered by the operator and Name the data set name be used does Zip that to not Address already exist. If neither test fails, the track Please add $2.00 per case shipping and handling charge. N.Y. State map is scanned for contiguous free space residents include sales tax. Al equal to the amount requested by the user. If the free space is found, the necessary bits are reset to 0 in the track map. The data set control block is now built by moving the required data into an empty block in the table of contents. The sector map is also on updated the sectors used the Sold to reflect by directory and the updated volume table of contents is rewritten on the disk, com- pleting the allocation of a data set. Soli To allocate a member, the user must provide the volume serial number of the disk as well as the name of the data set of which Talk the member will be a part, the member's toThe name (six characters maximum), member Microcomputer data type, and the number of sectors to allo- P eople A Sol computer system can be a big help to any cate to the member. The allocator program small business. In more ways than one. Solis versatile. It can do your ledger. Solve engineering again verifies that the proper disk is on line problems. Help you keep up with paperwork. Sol can even entertain and that the data set exists. Obtaining the you. Sol will do most of the things you can do with a minicomputer, address of the partitioned data set's direc- for one quarter the cost. And it can grow with your ability to use it. tory from the control block for the data set, Sol is dependable. Each one comes with a full year's warranty. And when you do need service, just call us. We don't sell what we the allocator verifies that a member with the can't keep running! same name as that being allocated does not If you, along with hundreds of others, are sold on Sol, there's already exist. If all is well, the sector map is only one thing left to do. Talk to The Microcomputer People " at scanned for contiguous free space in the Computer Mart of New Jersey and Computer Mart of Pennsylvania. data set's data storage area sufficient to Write or call us today. Sol is brought to you from Processor Technology by The satisfy the user's request. If space is available, Microcomputer People." an empty directory record is used to create a directory entry for the member. The Processor Technology sector map is then updated and the directory Computer Mart of New Jersey and table of contents are rewritten on the 501 Ro ute27. Iselin, NJ 08830 201 -283 -0600 Tue -Sat. 10 00-6 00 Tue. 6 Thur. tif 9 00 disk. Computer Mart of Pennsylvania We now have a partitioned data set with The Microcomputer 550 DeKalb Pike. King of Prussia. PA 19406. 215-265-2580 People e Tue Thur 11 00-9 00 Fri. 6 Sat 10 00 -6'00

Circle 73 on inquiry card. December 1978 © BYTE Publications Inc 171 Circle 374 on inquiry card.

TERMINALS FROM TRANSNET a member allocated in it. To use this mem- PURCHASE ber, we need an access method to perform 12-24 MONTH FULL OWNERSHIP PLAN the input /output (10) operations involved 36 MONTH LEASE PLAN in opening the data set, finding the desired PURCHASE PER MONTH member, reading and writing the data in PRICE 12 MOS. 24 MOS. 36 MOS. DESCRIPTION the member, and finally closing the data S 75 S 52 DECwriter II $1,495 $145 set. In addition, it is useful to have the 137 95 DECwriter III, KSR 2,695 257 access method open members sequentially. DECwriter III, RO 2,095 200 107 73 Given such an access method, we could DECprinter I 1,795 172 92 63 VT100 CRT DECscope 1,595 153 81 56 graduate from doing physical 10 to a far TI 745 Portable 1,875 175 94 65 simpler logical IO in which we need only TI 765 Bubble Mem 2,995 285 152 99 specify the volume serial number of a disk, 66 TI 810 RO Printer 1,895 181 97 a data set name and a member name in TI 820 KSR Terminal 2,395 229 122 84 order to read or write data. The access QUME, Ltr. Qual. KSR 3,195 306 163 112 QUME, Ltr. Qual. RO 2,795 268 143 98 method takes care of error processing, ADM 3A CRT 875 84 45 30 10 initialization and completion. The HAZELTINE 1400 CRT 845 81 43 30 access method would be used by the source HAZELTINE 1500 CRT 1,195 115 67 42 editor for saving source lines in members, . 56 HAZELTINE 1520 CRT 1,595 153 81 and the assembler would use it for reading DataProducts 2230 7,900 725 395 275 program source lines and writing program DATAMATE Mini floppy 1,750 167 89 61 FULL OWNERSHIP AFTER 12 OR 24 MONTHS object code. This means that two members 10% PURCHASE OPTION AFTER 36 MONTHS would be open simultaneously, but the ACCESSORIES AND PERIPHERAL EQUIPMENT access method should be able to handle ACOUSTIC COUPLERS MODEMS THERMAL PAPER RIBBONS INTERFACE MODULES FLOPPY DISK UNITS that situation. PROMPT DELIVERY EFFICIENT SERVICE In order to free space on the floppy disk, deletion programs are required. Scratching RAÌNSNET CORPORATION a data set would deallocate the space used 2005 ROUTE 22, UNION, N.J. 07083 by the members in the data storage area 201 -688 -7800 (recorded in the sector map) and clear the track map bits used for the overall space allocation for the data set. The data set control block is then filled with binary Os, freeing all space previously allocated. Scratching a member requires that the sector map be updated and the directory entry for that member be rewritten as binary Os. The deletion programs should be written to be as forgiving as possible of operator errors. After the operator has finished giving the delete command, the program should echo the command and wait for operator verification. All this is needed in order to avoid accidentally destroying irreplaceable data. Another useful program is the volume Don Lancaster's ingenius design provides software table of contents lister. The list program controllable options including: reads the data set control blocks from Scrolling Full performance cursor disk, formats and displays the informa- Over 2K on- screen characters with only tion contained in them, and indicates how 3MHz bandwidth much space is allocated to each data set and Variety of line /character formats including how much free space remains. As an added 16/32, 16/64 .... even 32/64 feature, the lister could be made smart enough to use the data in the data set User selectable line lengths control blocks to find and display the contents the member's entries, TELL ME MORE! ( send instruction manual for the TVT -6 Kit of directory with full operational details. $1 enclosed. thereby providing a powerful tool for ( SEND FREE CATALOG controlling the data on the disk. Name: As with all good things, the free space Address. on the disk will soon come to an end. The obvious solution is to delete a few members ELECTRONICS. INC. City: Statt: or data sets to make room for new things, but this has the disadvantage destroying DEPT. 12 -B, 1020 W.WILSHIRE BLVD., OKLAHOMA CITY, OK 73116 of

172 December 19780 BYTE Publications Inc Circle 298 on inquiry card. Circle 81 on inquiry card.

ESSENTIAL programs and data that may be important. Good Software is Essential for an Efficient Business. s A better solution would be to place Now, the finest in software at a price you can afford. We are definitely the affordablesl these programs into cheap archival storage PROGRAMS CURRENTLY AVAILABLE: li in a format that simplifies their restoration INVENTORY PROGRAM PACKAGE onto the disk. Thus, the members or data sets Inventory Addition to be saved would be written to magnetic Update tape by an unload program and written j;Search back on the disk later with a load program. Analysis (Current month) a The unload program reads the data set Analysis (Year to date) Vendor File control block of the data set to be unloaded Also generates 7 additional user reports and much, much more. and writes it on tape. It then reads the direc- Cost $175.00 - - si tory entries for the members of the data MAILING LIST PROGRAM set and writes the one selected to tape, fol- Print formating in 80 or 132 columns. lowed by the data for the member from the - Cost $20.00 - data storage area. It continues to write direc- The above programs are designed to run under the following: s CP in CBASIC ( tory entries followed by member data until /M also IMSAI IMDOS 'CP/M in BASIC E the request entered by the user is completed. in Debbi (Source code included) ICOM FDOS -III The load program reads the data from the 8" Disk IBM 3740 Format. i tape and necessary allocates data sets and if EXTENSIVE CONTRACTORS ESTIMATING PROGRAM members before writing the data into them Literature available upon receipt of your letterhead from the tape. Currently Under Development: The partitioned data set file organization Billing technique has been used successfully on Payroll many large systems and can be easily adapted General ledger for use by the hobbyist. In order to avoid Specializing in custom software for the AM -100 Datafacs System Inc. Eastern Division a situation similar to that encountered with 2440 W. Catalpa, Chicago, III. 60625 audio cassettes, standards should be formu- CP /M is a Trademark of Digital Research Corp. lated now so that disks can be interchanged AM -100 is a Trademark of Alpha Microsystems. from user to user.

Art -by- Computer Em is here! 22 START -AT -HOME IlCOMPUTER BUSINESSES in "The Datasearch Guide to Low Capital, Startup Computer Businesses" CONSULTING PROGRAMMING SOFTWARE PACKAGES COM FREELANCE WRITING SEMINARS TAPE /DISC CLEANING FIELD SERVICE SYSTEMS HOUSES LEASING SUPPLIES PUBLISHING TIME BROKERS HARDWARE DISTRIBUTORS SALES AGENCIES HEADHUNTING TEMPORARY SERVICES USED COMPUTERS FINDER'S FEES SCRAP COMPONENTS o File 13 File 60 COMPUTER PRODUCTS AND SERVICES FOR THE HOME Plus -- Loads of ideas on moonlighting, Black -on- white, 9 3/4H by 12 3/4W reproductions going full -time, image building, revenue of computer generated designs. See Jan 78 Byte building, bidding, contracts, marketing, professionalism, and more. No career or a 12 phone or write for flyer. Set of for planning tool like it. Order now. If not $20.00; singles $2.00 each. Minimum order: 2 completely satisfied, return within 30 prints. Orders less than $10.00 and all orders days for full immediate refund.

from cutside continental U.S. add $2.00 for 81/2 x 11 ringbound 156 pp. $20.00 and Payment be in US postage handling. must Phone Orders 901-382 -0172 dollars. California residents add 6% sales tax. Master Charge OK (include card # and DATASEARCH exp. date) or send check or money order to. Incorporated 5694 Shelby Oaks Dr., Suite 105. Dept. B. Memphis, TN 38134 Leland C. Sheppard Rush of "Low Capital Startup Computer Bus,nesses" a I $20 PO Box 60051, Dept. B -copies per copy to me right away. Sunnyvale, California 94086. Phone: (408) 733 -8651 NAME /COMPANY ADDRESS Also available at selected retail outlets. CITY /STATE /ZIP Check Enclosed D Bankamericard D Master Charge

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Circle 93 on inquiry card. December 1978 ©BYTE Publications Inc 173 Ppopamming Quickies

Tic -Tac -Toe in BASIC

Mike Stoddard Tic -Tac -Toe is a game that has been few logic errors which put the player on a 16681 Lynn St turned into a computer program thousands more even level with the computer. There is Huntington Beach CA 92649 of times. Although it is fun to play with a a fighting chance against the now imperfect computer, the best a human opponent can opponent. The program logic that scans the hope for is a draw game. After a short time rows, columns and diagonals has been the player loses interest because he or she altered to produce countermoves much like never has any chance of winning. My version those of a person just learning the game. plays a regular game except that there are a After playing dozens of games with the machine, if the player is lucky, the pattern of moves that fool the machine will emerge

THE GAME OF TIC- TAC -TOE. WERE ARE 4 POSSIBLE GAMES Figure 1: This one and allow the player to beat the machine is of WHICH YOU CAN WIN. THE BOX SQUARES ARE NUMBERED* the patterns that can be every game. One such pattern is shown by I 2 3 used to always beat the 4 5 6 the sample game of figure 1. 7 8 9 computer. There are three To change the program logic back to AM NOW READY TO PLAY. YOUR MOVE FIRST. a other winning strategies 4 I WILL PUT AN X IN BDX 5 YOUR TURN. playing perfect game every time, change 2 LETS PUT AN X IN BOX 9 YOUR TURN. the value of Z at line 1140 from 1 to 2. that will result in a win for I AN X IN BOX 3 WILL STOP YOU. YOUR TURN. 7 CONGRATULATIONS. YOU WIN THIS GAME. the human player. This hint should allow any good hacker to

O o x figure out how the program works inter- O X - nally. You can have fun playing the com- n - X puter and showing your friends you are, I AM NON READY TO PLAY. YOUR MOVE FIRST. indeed, smarter than the computer!

No adjustments. No calibration. What it means to you. OPTIONS

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174 December 19780 BYTE Publications Inc Circle 359 on inquiry card. Listing 1: BASIC source code listing for 1500 IF L1<>2 LOTO 1570 1510 IF L(1)'L(3)<>13 LOTO 1570 Tic - TacToe game. 1520 IF K(1,3)<>9 LOTO 1570 1530 LET N.:I 1540 LET K(1,3).4 1550 LET K(l,2)I 1000 REM "14" = =a- TIC- TAC-TOE WITH A TWIST 1560 LOTO 1760 1010 REM 02 -05 -77 WRITTEN BY MIKE STODDARD 1570 LET N ? =:1 1020 REM 1580 COTO 1200 1030 DIM K(3,3),L(9),C4(12) 1590 LET M =3 1040 PRINT " \215 \THE GAME OF TIC -TAC -TOE. THERE ARE 4 POSSIBLE GAMES. 1600 LET 111,5 1050 PRINT "WHICH YOU CAN WIN. THE BOX SOUARES ARE NUMBERED:" 1610 LOTO 18'/0

1060 PRINT " \215\ 1 2 3 \215\ 4 5 6 \215\ , 7 8 9 \215 \" 1620 LET 1417 1070 FOR I =1 TO 3 1630 LET N1 =2 1080 FOR J =1 10 3 1640 COTO 1090 1090 LF1 K(I,J) =9 1650 LET M =11 1100 LE1 LI(I- 1) +3+J) =0 1660 LET N1'3 1110 NEXT J 1670 COTO 1090

1120 NEXT I 1680 LET M. 1'? 1130 LET K3.1 1690 LET N1=4 1140 LET Z =1 1700 LOTO 1090 1150 PRINT "I AM NOW READY TO PLAY. YOUR MOVE FIRST. 1710 LET L(6) =N 1160 COSUB 29(10 1720 LOTO 2960 1170 IF F.1 CO10 1160 1730 LET L(6) =N 1180 LET L(1)=Ll 1740 PRINT lAH (7). "AN X IN BOX ";N; "WILL STOP YOU. YOUR TURN." 1190 LET 02.1 1750 LOTO 1820 1200 COTO 2400 1760 LET L(6).N 1210 IF K(2,1')<>9 LOTO 1250 1770 PRINT TAR (7). "I WILL PUT AN X IN YOUR TURN " 1220 LET K(2,2).4 1780 LOTO 1020 1230 LET Neu 1790 LET M =27 1240 COTO 1270 1800 LET 1S3 =5 1250 LET K(1,11.4 1810 LOTO 10'10 1260 LET N=l 1820 GOSUB 2900 1270 LET L(:)N 1830 IF F =1 COTO 1820 1280 PRINT 1A8 (7), "I WILL PUT AN X IN BOX ")Ni" YOUR TURN." 1840 LET K1'2 1290 OOSUB 2980 1850 LET L(/) =1.1 1300 IF F.1 GOTO 1290 1860 LET N2.4 1310 LET L(3)=L1 1870 LOTO 1200 1320 LET N2 =2 1880 REM COIUUMN ADD SUBROUTINE 1330 COTO 1200 1890 LET K2 =1 1340 LET M =11 1900 FOR I =1 TO 3 1350 LET N11 1910 LET N4 =0 1360 COTO 1090 1920 FOR J1 TO 3 1370 ON I COTO 1420, 1380 1930 LE1 N4'N4 +K(I,J> 1380 IF L(1) +L(3)< >6 COTO 1420 1940 IF N4 =M LOTO 2230

1390 LET N. I 1950 NEX1 J 1400 LET P(1,1)(4 1960 NEXT I 1410 COTO 1440 1970 LET K2 =6' 1420 LET M=22 1980 FOR J =1 TO 3 1430 COTO 1890 1990 LET N4 =0 1440 LET L(4) =N 2000 FOR I= 1 10 3 1450 PRINT lAB (7)i "LET'S PUT AN X IN BOX ",Ni" YOUR TURN." 2010 LET N4'N4 +K(I,J) 1460 COSUB 2900 2020 IF N4 =M LOTO 2230 1470 IF F.1 G010 1460 2030 NEX1 1 1480 LET L(5) =L1 2040 NEXT J 1490 ON Z G010 1570, 1500 2050 LET KP'

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Send us your check or money order NOW! Motorola Microprocessor Evaluation Kit Il We can also bill to your Master Charge or Visa if you include the number and expiration date. Enclose total for entire package or any items desired plus applicable state and local It includes: taxes (include an additional $5.00 for shipping MEK68R2 ... $199.95 and handling). Be sure to include your name Accessory board for complete interface between D2 Kit, ASCII and address and print clearly, making checks keyboard and video monitor or TV set. Has custom ROM with payable to Motorola Inc. video driver. Mall to: -Software programmable line and character format: Motorola Mail Order Sales 16 x 32, 16 x 64, 24 x 80 -up to 24 lines by 165 characters. P.O. Box 27605, Tempe, AZ 85282. -5 x 7 character format with upper and lower case. MEK6800AB ... $79.95 a Motherboard with card guide, two 86 -pin slots and five 60 -pin slots. MMS68104 ... $395.00 4 Memory board with 16K x 8 bytes of RAM. POWER SUPPLY ... $99.50 Fully- regulated +12 Volts at 1 Amp and +5 Volts at 6 Amps ... r capable of powering complete system with possible expansion. MEK6800D2 ... $235.00 MOTOROLA The ever popular D2 (in Kit form only) to develop and evaluate Semiconductor Products Inc. M6800 Microprocessors.

2060 LET N4 =0 Languages 2070 FOR 1,1 lO 3 2080 LET J =1 2090 LET N4 =N4 +)((I,I) 2100 IF N4-M LOTO 2230 FORM 2110 NEXT I 2120 LET K2 =4 2130 LET N4 =0 On Expressing 2140 FOR I =1 TO 3 2150 LET J =4 -I 2160 LET N4 =N4'K(I, J) 2170 IF N4 =M LOTO 2230 Multiple Condition 2180 NEXT I David Faught 2190 IF K3=5 GOTO 2210 2200 ON NI LOTO 1370, 1650, 1680, 1790, 1620 603 S Hazelton Av 2210 PRINT TAB (7), "THE GAME IS A DRAW." 2220 LOTO 2700 Wheaton IL 60187 2230 IF M =3 LOTO 2260 2240 IF K(1,.1)'9 LOTO 2500 2250 ON K2 GUTO 2290, 2310, 2330, 2360 Having been interested and active in corn - 2260 PRINT TAB (7), "CONGRATULATIONS. YOU WIN THIS GAME." 2270 LOTO 2700 puter programming for some 10 years, I have 2280 REM COEFFICIENT EVALUATION SUBROUTINE 2290 LET Jß,1 .1 watched with great anticipation the advent 2300 LOTO 2240 2310 LET 1=1-1 of the personal computer. In my own hobby 2320 LOTO 2240 and professional I have used 2330 LET 1.1 d programming, 2340 LET J=.Y -1 a rather large number of languages and have 2350 LOTO 2240 2360 LET 1-I -1 discovered through many painful experi- 2370 LET ,1 =Jrl 2380 LOTO 2240 ences and uncounted hours of debugging 2390 REM CONVENT 1 -9 SUBSCRIPT TO I -J VALUE 2400 LET N4,0 that, in general, regardless of the language 2410 FOR I =1 TO 3 2420 FOR J =1 TO 3 being used, a modular top -down approach 2430 LET N4 =N4 +1 developing new programs is by far the 2440 IF L1 =N4 LOTO 2470 to 2450 NEXT J easiest to understand and use. Unfortu- 2460 NEXT 1 2470 LET )((1,J) =1 nately, my first experiences with program- 2480 ON N2 GOTO 1210, 1340, 1590, 1590, 2740 2490 REM CONVERT I -J VALUE TO 1 -9 SUBSCRIPT ming consisted of occasional use of a Tele- 2500 IF N2í)4 GUTO 2550 2510 IF N1 =2 Gm O 2540 type terminal on a timesharing BASIC 2520 LET 2530 LOTO 2:5I,0 system. I still use BASIC for some of my 2540 LET NIA 2550 LET K(l,J) 4 hobby programs, but I find that unless some 2560 LET N=0 skill in program organization is used, a 2570 FOR J1=1 '10 3 2580 LET N,N'I BASIC program can very easily become a Everything you always wanted

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176 December 1978 O BYTE Publications Inc Circle 202 on inquiry card. rat's nest of inserted problem bypasses the languages mentioned above. ELSE we and altogether impossible to read. I recently forget, these languages also contain a state- obtained a copy of a primer on Pascal in ment which allows the testing of a variable the hopes that it would provide some state and the optional performance of one knowledge and insight into providing a pro- of several alternative functions depending per means of improving program structure on the state encountered. In BASIC, this is through language format and syntax rather the "ON . . . GOTO . . ." statement; in than relying on my own experience in this Pascal it is the "case . . . of ..." state- area. I can now see why this language has ment, and in COBOL it is the "GO TO ... become much more popular as a first lan- DEPENDING ON . . ." statement. FOR- guage in many universities and I hope that TRAN also has this capability in a limited it will continue to grow in popularity and way through the use of the numeric IF wide usage. rather than the logical IF. In my humble

At various times in the past I have tried opinion, Pascal's implementation of this my own hand at designing a source language feature is far more meaningful not only which would provide a much more meaning- to program structure but also to under- ful approach to program structure which standing the condition which is actually must be at least as important as function. I being tested. Many times when this struc- Figure 1. have no new language to propose in the ture is used in BASIC or COBOL, it is the cause of this interest, having never tried to powerful feature which justifies the use IF condition 1 statement 1 condition 2 statement 2 implement one of the languages I have of that "hairy" computation to adjust condition 3 statement 3 designed, but I do have some comments the conditions which are actually present which may be of interest to those who are to be an integer between 1 and 10. Pascal's also involved in the search for the "perfect implementation of this structure is still condition n statement n language." not perfect because it takes some extra In various languages, to my knowledge effort in defining data types to assure END including BASIC, Pascal and COBOL, there that one of the alternatives will indeed ELSE statement is at least one statement which tests a condi- be picked. Correct me if I'm wrong, but tion and will or will not perform a specified there is no explicit way to specify what function depending on the outcome of the should be done if none of the states for test. This is, of course, the IF statement in which there are alternatives is actually

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Circle 82 on inquiry card. December 1978 © BYTE Publications Inc 177 Figure 2. found. I believe it would also be somewhat not evaluating the original condition 1 if tricky to use this single Pascal statement statement 1 is omitted. This means that to perform one function if the variable only the concatenated expressions which IF X being tested is less than 50, to perform are formed will actually be evaluated. Simple <50 PRINT X; another if the variable equals 50, or to examples of possible forms of this type of a = 50 PRINT X;XX a the value is statement are shown in figure 2. >50 PRINT X perform third if greater than

50, for example. I believe that this statement structure END These are obviously closely related condi- provides an excellent aid to properly or- tions and would ideally be resolved with a ganizing program structure. It has the simple statement structure. Note that these capability of directly relating associated IF X = types of tests are possible in most any states in an easy to understand manner

1 SET Y =X language: however, my suggestion is that and provides the flexibility which a multiple 2 SET Y, Z =X there should be an alternative to this some- condition test should have, without having 3 SET Z =X times confusing structure. to go through any complex manipulations END Rather than having one statement to test to resolve the conditions present to any a single condition and another to resolve particular restrictive form. ELSE multiple conditions, why not make the I would welcome any and all comments SET X =1 single condition test a simple subset of the on this proposal and am always interested multiple condition test? A loosely defined in finding more about the "perfect lan- statement structure which would satisfy guage" if you have any suggestions. IF X =0 this requirement is shown in figure 1. As this LET Y =ZZ statement is parsed, the statement becomes Perhaps a reader with language design a multiple condition test when it contains experience would core to comment on the AND Y =1 multiple conditions. When additional condi- various examples and suggestions proposed. PRINT Z tions are encountered, each is concatenated Readers should note that none of the to the first condition to form a new condi- examples of figure 2 follow the prototype AND Y =2 tional expression which is then evaluated to of figure 1 completely. But the examples PRINT Z, Y determine if the statement associated with of figure 2 might provide interesting vari- the new condition should be executed or ations on the multiple condition suggestion END not. The one restriction I would like to see if they prove unambiguous to a language ELSE PRINT X on this type of a structure would entail translator or interpreter.... C H

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178 December 1978 ©BYTE Publications Inc Circle 84 on inquiry card. J O'Loughlin can handle without the demands a second 908 Salem Dr language would require. Huron OH 44839 It should also be pointed out that Pascal has little or no following outside the aca- Pascal Critique demic community. It wouldn't be the first time that a language enjoying a great deal of a admiration at the academic level has failed and Comment to gain acceptance as a viable tool in the real world of data processing. Languages are used and live only on the basis of perceived use- I have just finished reading your August fulness, the availability of experienced

1978 issue and would like to comment. I practitioners, and widespread implementa- am more than a little disappointed with the tion of the language. Pascal now has none of volume of coverage given to Pascal. Whatever those attributes. the relative merits of the language that In my opinion the number of users of amount of discussion isn't merited in my any language speak many silent volumes that opinion. There currently is no affordable by weight of numbers signal acceptance of a implementation of the language available to language more than any theoretical pro- the typical computer enthusiast. If and when posals or arguments about the relative

Pascal is available I believe it will have a very advantages of competitive languages. rough battle trying to compete with both the pricing and heavy usage that BASIC en- But there is an affordable implementation joys today. of Pascal - the UCSD system is available

Another problem I think you have failed separately, or bundled with various manu- to address is the effect of the huge invest- facturers' products. As a means of learning a ment in time and money many have made in new language, conversion of one or two pro- BASIC. Just what is to become of that? Con- grams as tutorial experiments is just fine. version? An unlikely prospect given the Pascal should only be thought of as an historical example of the COBOL and PL /I avenue to more effective creation of new controversy. Use both languages? Again an programs. unlikely prospect. Most people have all they As for "no following outside the academic

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Continuing Comments on APL have to map out in advance exactly what it is he will ask the machine to do. At the root of the matter is the consideration that there is no clean distinction between "implementing a program" and Timothy J Stryker John Howland's "Comments on APL's simply "invoking a system utility." Suppose, 477 Hope St Characteristics" in the May 1978 BYTE for example, we wish to check on the value

Providence R 1 02906 Languages Forum, page 143, are for the of some variable, for example J, during an most part well thought out. However, it APL terminal session. We simply type: seems to me that he is missing something when he states that an APL programmer who composes programs on line is "similar Now suppose that the value of J is lower to the person who opens his mouth and than we expected, so that we become inter- begins to speak before engaging his brain." ested in the first J elements of the array A. The whole point of having an interactive We type: language facility is based on the fact that the programmer does not always want to Af t 'lleca J) suIINIIIIN;CS -1 beta _1 The stand -alone I icta Tape Storage System. BETA -1 is the answer to the many requests MECA has received for a universal tape unit. So we are proud to present the first mass storage solution for non -S100 bus microcomputers. Now you can own a BETA -1 complete, assembled and tested, for only $399. STANDARD FEATURES

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180 December 1978 © BYTE Publications In Circle 220 on inquiry card. But now perhaps we realize that j is actually able to get, on line, while still maintaining the number of pairs of quantities in A and so cogency of thought, the more productive in order to examine the set consisting of he will be. the first element of each pair we type: Mr Howland justly defends APL's right to left order of evaluation from those who A[-1+2Xi J] would make it left to right: 3 -6 equals 2 is not a pleasant prospect. However, a I could go on, but I think the point is clear: valuable property for any language /environ- at what level of complexity have we stopped ment to possess is one which allows short, merely using the facilities of the environ- transparent programs to be entered quickly ment and started writing a program? and easily, without any need for pencil and My own view is that the above distinction paper in the process. My suggestion to the is immaterial and that what matters is simply APL terminal manufacturers, if they haven't that the environment be structured to done so already, is to implement an option maximize the programmer's capability to whereby each line could be entered from accomplish the job at hand expediently. right to left (in much the way one fre- When the job at hand is large and compli- quently find oneself writing out lines of APL cated, there is no question but that at on paper, that is, starting at the righthand present hardware costs the most expedient edge and working leftwards). In this way, recourse involves writing out the bulk of the objective of simplified on line program what is to be typed in beforehand. Likewise creation could be achieved at no cost in the when the job at hand is trivial and trans- way of incompatibility with existing APL parent (eg: inspecting A[ t J ), it is undeni- processing precedence. ably the case that writing it down before typing it in is a waste of time. In between Reacting just slightly to the last para- these two extremes, things are not so clear, graph of your letter, a question comes to and the point at which paper and pencil mind: is it the terminal manufacturer's become necessary will depend both on the responsibility or the APL interpreter- writer's individual programmer involved and on the responsibility to make the input sequence system. However, what is clear is that the run from right to left? With a fast enough more complex the programmer finds himself terminal, it is possible to rewrite the last

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Circle 378 on inquiry card. Circle 77 on inquiry card. BYTE December 1978 183 A Proposal for a Kitchen Inventory System, or Technical Don't Byte the Wand That Feeds You Forum

Richard Shuford A practical and natural application for ing the software may be used to read the Editor your home computer is an inventory system Universal Product Code. The scanning for the kitchen. Such a system would relieve wand provides a quick and easy method humans of the details involved in making to identify a given item without keystroking out a grocery list. any information into the computer. It One convenient way of keeping track of will, unfortunately, be necessary to do some the various items in the pantry is to use keystroking to set up the system. One the information that is now provided on minimal implementation of an inventory most food packages specifically for that system might be set up in the following purpose, namely, the Universal Product manner. For each grocery item in stock, Code, or UPC. This is, of course, put there a data base would exist containing: for use by food stores, but there is no reason that the UPC cannot be used in the home. a representation of the Universal The Universal Product Code appears Product Code for a given item, Technical Forum is o fea- on a product label as a patch containing a human language description of ture intended os on interactive bar codes, with a line of human readable the product including brand name, dialog on the technology of personal computing. The sub- numbers underneath. This distinctive design generic name, and size or quantity, ject matter is open -ended, and has now become familiar to most North the minimum quantity that should the intent is to foster dis- American shoppers. Information contained be kept on hand, cussion and communication in the bar codes can be read by an optical optional information on the item's among readers of BYTE. We sensing device connected to a computer. ask that oll correspondents shelf life, supply their full names and At present many computer experimenters any other information which is addresses to be printed with are equipping their computers with an deemed useful (for example, which their commentaries. optical sensing device, a bar code reader members of a household like a partic- that has a scanning wand, for the purpose ular item). of scanning the new machine readable software which uses similar bar codes. A As the supply of an item becomes de- good example of such software is the pleted, the container is thrown out. Immedi- PAPERBYTEtm series of books which ately before disposing of the container, BYTE Publications produces. It is probable though, the UPC bars are scanned. The that the same scanning wand used for read- computer stores this code in a table of

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184 December 1978 ©BYTE Publications Inc Circle 400 on inquiry card. items which are depleted and should be cardinal rules of computer use, which is: restocked. Prior to setting off on a shopping garbage in - garbage out. trip, the user requests a display (preferably Special arrangements would still be on a hard copy device) of depleted products. necessary to handle those products not The computer uses the depleted products marked with the UPC in many stores, such table to reference the master data base, as fresh meat and local produce. It might and retrieves the human language description be possible, with knowledge of the encoding of the product from the master data base method of the UPC, to make a custom UPC and displays it for the user, along with other bar code symbol by hand. This could be information. If the display is on a hard copy mounted permanently near the garbage can device, the user simply tears off the paper scanning station and scanned instead of a and uses it as a grocery list. package symbol. The computer could then Probably the best way to establish and at least note that the supply of a non - maintain the data base is with the use of an encoded item was depleted and call atten- interactive program. The user would build tion to the fact. the data base from scratch by starting with An ingenious tinkerer could no doubt those items on hand at the time. For each find many ways to improve the system. item, the UPC bar codes are scanned, then For example, some means to indicate the user types in the other information exactly which nonencoded item is depleted about the item. (Note that it is not necessary might be devised. And it might prove useful for the numeric product code to be key - to scan a package as it is bought, to verify stroked by the user.) After the initial data that it is back in stock. Also, the addition is stored, the interactive program may be of a modem for telephone communication executed to update the file with information gives rise to many possibilities. for new or different products. It is not A computer equipped with a modem necessary to start with a huge data base could, with the proper programming, call containing data for every possible product. a computer equipped food store and auto- Each household would keep information matically order the necessary grocery items. tailored specifically to its needs in its data And given the proper programming both base. in the home and at the store, it could dial The size of the data base is dependent up several different stores, compare prices on the number of different products a given and order from the store which provides household buys. It should be noted that the lowest price for the entire list. With each brand of a given generic item has its electronic transfer of funds, the computer own code. The data base may be kept small could even automatically pay the grocery if a single brand of a given item is used bill. consistently. The procedure of reading the Automating the kitchen inventory should UPC bar codes just before consigning the give people the time to develop new recipes container to the garbage follows one of the or new computer applications.

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Circle 401 on inquiry card. December 1978 BYTE Publications Inc 185 He did not want his optional entertainment chip tampered with; his films, recordings, reading and fantasy trips had all been carefully selected,

carefully tested over the Lawrence F Willard years. POB 202 Yalesville CT 06492

At the moment he was staring at the glowing figure 3 in disbelief. Three messages The Mother Chip for him during the night? How unusual! Twombly was a nobody; no family, no friends, no job. He didn't have to work, and so never would be allowed to. He lived on the regular income from his trust fund, Jonathon Witherspoon Twombly floated and, with Minnie's help, he kept his outgo up out of a warm and comfortable world of exactly equal to his income. It was a good drifting, unconnected images to begin, un- life. fortunately, a new day. He stared at the He removed Minnie from her niche and cream colored ceiling, as he always did, to keyed in a command. The four foot square read the wedge of light that fanned from screen built into the wall at the foot of his the top of the window shade to intersect bed lit up and the readout began: a discolored area of the ceiling in a fairly significant manner. Nine o'clock, he guessed, MSG 1 BELLOGRAM 7.6.97 2207 66234621 disdaining for three and a half seconds the BP P12 TWOMBLY, JONATHON W 779 28 88980 BMA absolute accuracy of his Minnie on the YOU ARE HEREBY CITED BY TRAFFIC bedside table. He rolled over and looked CONTROL OFFICER 229 BOSTON CITY at it, stubbornly translating 24 hour time POLICE FOR MOVING TRAFFIC VIOLATION to his own archaic measure. His guess was 7.6.97 1201 HOURS PL 2395 SEC. 8. B. SECTOR a mere four minutes and ten seconds slow. QUADRANT 9 FINE 25 DOLLARS REMIT WITHIN 24 HOURS TO AVOID ARREST Pretty close, he noted contentedly. PC JOHN KELLEY. The mini -mini -micro -processor, his own personal computer link to the vast and Twombly swore mildly (he was not an complex world of 1997, winked at him aggressive man). He'd had the car on manual with a softly glowing numeral 3. Not much five minutes during the entire day and he'd larger than a deck of playing cards and managed to get a ticket. He might as well half as thick, Minnie rested upright in pay now and get it over with. He didn't even her umbilical slot, absorbing power for her bother to call up the picture the cops had About the Author batteries and sharing her thoughts with the surely filed. He didn't want to see himself house computer in its basement hideaway. on the screen making an ass of himself. Pay- Lawrence F Willard has A rather old microprocessor, Mike ran the ment of the fine would wipe the picture out been a journalist and free house, but Minnie was boss as long she was of the police computer banks. He punched lance writer for over 30 plugged into the table, or as long she was on up his bank balance, confining it to Minnie's years, contributing to Twombly's person and not more than a mile small screen. $207.81. Even with seven cents many magazines, including distant from the house. Beyond that range added as interest during the night, it wasn't New Hampshire based she could integrate with Mike up to a a healthy balance. He swore again, mildly, Yankee Magazine. A ham distance of 40 miles using the high power and punched in the command, the amount radio operator, Larry car facilities, and beyond the 40 mile radius and the police computer address, checked it teaches journalism and she could use the worldwide network of on the screen and punched the execute media courses at Man- relay stations. But that cost money and was button. $182.66. The city had $25; the chester Community Col- rarely necessary. Jonathon Twombly did not bank had its 15 cent service charge. lege in Manchester CT. travel very much or very far. Twombly called up the second message:

186 December 1978 : BYTE. Publicaiium Inc Circle 138 on inquiry card.

MSG 2 VIDEOPHONE CALL 0231 7.7.97 CENTRAL HOTEL RM 63 Be SELECTRIC® in your HI TWOMB OLD CHAP. REMEMBER ME? PUDDY, ROOMY, WESTERN U? IN TOWN choice of output printing FEW HOURS. HOW ABOUT A DRINK? NOW. LEAVING SUNUP. 766 26 0589 CHEERS. The highest quality printer available is affordable to you as your output printer. Any IBM SELECTRIC' Twombly shuddered, wiped the screen typewriter can be converted. clear. He had set Minnie to store night calls, Does not affect normal operation or appearance. not wake him up; he wasn't sorry. He called Uses existing screw holes in the typewriter, thus up the last message: no tapping or drilling is necessary. Does not affect eligibility for IBM warranty or MSG 3 BELLOGRAM 7.7.97 0800 66091532 service when installed according to ESCON FBCC BOSSOFF TWOMBLY, JONATHON W instructions. 779 28 88980 BMA YOU ARE HEREBY REMINDED Compare the economics: APPOINTMENT THIS OFFICE ANNUAL ESCON Conversion System $ 496.00 CHECKUP AND FIVE YEAR REPROGRAMMING 1400 HOURS THIS DATE. New IBM SELECTRIC° PREPARE FOR ROUTINE PHYSICAL, (purchased from IBM) $ 815.00 PSYCHOLOGICAL TESTS TO DETERMINE Complete high quality printer $1311.00 AGING FACTOR. ALL NEW PROGRAM CHIPS TO BE INSTALLED, INCLUDING OPTIONALS. Other SELECTRIC Conversion Systems Over $1800 YOU MAY RETAIN OR CHANGE OPTIONALS. tested and assembled (kits available) NOTE: WHEN THE HELL ARE YOU GOING TO LET US REPLACE YOUR ANTIQUATED Choice of S -100, RS232, IEEE -488 or parallel port. MINI FOR NEW ATOM POWERED MODEL? Factory turnaround installation available. P. T. HARRIS BUCHIEF.

Twombly wiped the screen. Of course he Escon Products, Inc. hadn't forgotten. Minnie had already placed 171 Mayhew Way, Suite 204, an order for a car. Good old Minnie. Like Pleasant Hill, CA 94523 hell they would replace her. Not yet. He sat (415) 935 -4590 for a moment, thinking. They'd find him five years older, reflexes a bit slower. New programming would compensate. Obstacle detection devices would take over a little sooner when he drove on manual, putting CPFlids CPAids CPRids CPPids him a little less in control. His heart would be monitored more carefully and his medi- Microcomputer software developed by save unit would probably get newer, more a CPA with an M.S. in Accounting powerful drugs. Minnie would probably calm him down a little quicker when he got overexcited. Did he want his optional NOW! In time for the upcoming entertainment chip tampered with? No. tax season. His films, his recordings, his reading, his fantasy trips had all been carefully selected, carefully tested over many years. They MASTER TAX PROGRAM would do without futher change. Twombly got up, dressed (he wanted no Includes: Schedules - A, B, C, D, E, G, R, RP, TC, SE Forms - 2210, 4728, 4797, 5329, 4825 help from the waldos, those mechanical Optional Schedules - 2108, 2441 servants that Mike controlled), and dropped Computes Tax 8 different ways to Insure minimum tax liability Used to file hundreds of returns this past tax season

Also Available: STANDARD TAX PROGRAM Includes Schedules A, B, G & TC 00L -

Runs in north star basic, C basic and CP /M

96 CALL: [216] 678 -9015 Located at 1640 Franklin Ave., Kent, Ohlo 44240 (in th. Trans -Ohio Building) A division of COMPUTER TAX SERVICE

DEALER INQUIRIES WELCOME

Circle 79 on inquiry card. December 1978 © BYTE Publications In 187 Minnie into his inside jacket pocket from which nobody but he could remove it without calling out the police emergency vehicles and perhaps the National Guard; anyway, nobody had ever tried it. He went into his small but luxurious dining room to eat the late breakfast Minnie had summoned for him. He was served by one of his two household waldos, which glided across the carpet on a cushion of air, delicately bearing 64KB MICROPROCESSOR a plate of scrambled eggs in hands that could bend a steel I beam into a pretzel. Mike operated the waldos, using their MEMORIES sensory substitutes for eyes, ears and sense of touch. Twombly had programmed Mike S -100 - $695.00 to speak through the waldos' vocoder LSI 11 - $890.00 systems in an almost human male voice, and he had also fixed it so that when Minnie 6800 - $995.00 wanted to speak to him verbally through Mike, the waldos underwent a startling CI -s100 - 64K x 8 on a single board. change of sex, answering in suitable Plugs directly into the IMSAI, MITS, feminine tones. She spoke to him now TDL, SOL and most other S -100 Bus above the plate of scrambled eggs. computers. No wait states even with "I have ordered you a car, a Whinger Z80 at 4Mhz. Addressable in 4K in- Electric, to be here at one o'clock. Very few of the agencies still have those in their crements. Power requirement 6 watts. inventory. They are, as you know, obsolete. CI-S100 64K x 8 Price $695.00. Next year we will have to pay the antique CI -1103 - 8K words to 32K words in a car premium to get one."

single option slot. Plugs directly into "I know, I know; we'll worry about that LSI 11, LSI 11/2, H11 & PDP 1103. next year." Twombly ate his eggs, retired to Addressable in 2K increments up to his study and programmed the next lesson in 128K. 8K x 16 $390.00. 32K x 16 $890.00 his study course, "Late 19th Century and CI-1103 32K x 16 qty. one. Early Twentieth Century External Bathroom Architecture in Rural Areas." Fifteen CI -6800 16KB to 64KB on a single - minutes before the hour of one o'clock he .. 7111 board. Plugs directly into Motorola's llá was standing on the sidewalk in front of his EXORcisor and compatible with the townhouse awaiting the Whinger Electric. ` 1 ' evaluation modules. Addressable in He was not alone. Standing a few feet away 4K increments up to 64K. 16KB $390.00. from him was the occupant of the neigh- CI-6800' 64K x 8 64KB $995.00. boring townhouse, a Professor John or CI -8080 - 16KB to 64KB on single Carmody, who taught English to first year L ..a' e students at Radcliffe. Twombly wondered I board. Plugs directly into Intel's MDS whether he should activate his noninter- Lié2t 800 and SBC 80/10. Addressable in OltL{ ! course signal, but Minnie's low buzz indi- 4K increments up to 64K. 16KB $390.00. cated that the good professor had activated CI-8080 64K x 8 64KB $890.00. his own, thus solving the problem. It was, of course, the grossest kind of social blunder Tested and burned -in. Full year warranty. to speak to or take any notice of a person radiating a nonintercourse signal. Just then the signal stopped, and before Chrislin Industries, Inc. Twombly could activate his own signal, the Computer Products Division professor spoke to him. 31352 Via Colinas Westlake Village, CA 91361 213 - 991 -2254 "Since your signal is off, sir, may I be permitted conversation with you ?" Circle 46 on inquiry card. It was now too late to emit a nonintercourse signal, and the grossest kind of social impropriety not to answer. "My dear Professor Carmody, you may indeed converse with me," said Twombly. "Nice day, isn't it ?"

"Yes, I perceive you are waiting for a car ?"

188 December 1978 C BYTE Publications In l,llóle .40 ul I niyuiiy t.aik.i.

"Indeed, yes. I am headed into the center of the city, to government sector. Do you wish to share my car ?" "No, no, my dear Mr Twombly; my own is on the way. Would you be interested in a small wager, say five dollars, as to which vehicle arrives first ?" "That would be most sporting," agreed Twombly. "Shall we say ten dollars ?" "Done," said Professor Carmody. Although neither could now erect the nonintercourse barrier, by mutual unspoken 6800 OWNERS more was said. agreement nothing At exactly At last a real world fully addressable SS -50 one o'clock both vehicles came into view, control interface. Control robots, appliances, arriving from opposite directions. organs, solar devices, etc. Applications limited Twombly's arrived a fraction of a second only by your imagination. Easy to use with machine language as well as basic. Fully buffered before the professor's. The professor nodded board plugs directly onto mother board and rein token of defeat, and entered his car. sponds to any address defined by user. 8 fast Twombly's bank balance would shortly grow relays latch data while 8 opto- isolators allow by ten dollars. He felt very good about that. handshaking capacity. Kit $98.00 Entering the two seater electric, he took Assembled and tested $125.00 Minnie from his inside jacket pocket and inserted it in the slot in the dashboard. It EXTENDER BOARDS in was now his car, for a daily rental fee, until Extend both the 30 and 50 pin buses SWTP 6800. he removed Minnie and gave the car a signal Both for $19.95. to return to its depot. He put the car on Visa & Master Charge Ariz. Res. add 5% Sales Tax automatic and keyed in the destination. He WRITE FOR DETAILS could not get a traffic ticket as long as the car was under automatic control by the TRANSITION ENTERPRISES INC. city's own traffic computer which directed Star Route, Box 241, Buckeye, AZ 85326 the symbiotic duo of Minnie and the car's computer. Twombly leaned back, completely re- laxed in the knowledge that he was in the safest environment ever known to mankind. No matter what difficulties there were, through rain, fog, sleet or snow the car would transport him without danger. If he Having Reservations About Your Software had a heart attack, his medisave implant would go into action, administering RUNT NO MORE! adrenalin, electric shock, or whatever else Smoke Signal Broadcasting presents the was needed for the few minutes it would take for help to arrive. Minnie would work through the car computer and signal system 6800 Fortran to coordinate the meeting of the car with the nearest mobile medical unit, which Complete FORTRAN Compiler for the 6800 would be receiving a flow of medical data Produces Relocatable Object Code and electrocardiograms. It was exceedingly Included with the compiler is the Smoke Signal Linking to die in an automobile, or on the difficult Loader which loads the object code produced by the street for that matter. Minnies could work compiler into any portion of memory specified by the directly into repeaters mounted on tele- programmer. Fortran is completely integrated to operate phone poles no more than a mile apart with DOS68, Smoke Signal's Disk Operating System and throughout the entire city. is ideal for scientific applications, number crunching and At government center the car parked 3 dimensional array processing. FOR -68 $99.00 itself to wait until Twombly's return, since ATTENTION SWTPC MF -68 OWNERS: Our MF -68 -U he had not given it instructions to return kit includes DOS68 and extensive upgrades to your hard- to the depot. He took Minnie out of the ware to allow operation with all Smoke Signal Disk dashboard slot and returned it to his inside Software. MF -68 -U $269.00 jacket pocket, stepped out of the car onto a moving walkway, and was carried into the We're the "CHiEF" in 6800 products software building that housed the Boston office of the Federal Bureau of Computer Control. .le OKE SHIM, BROADCASTING'G He took the elevator to the twelfth floor 6304 Yucca /Hollywood, CA 90028/(213) 462 -5652

Office of Programming and Adjustment, where he underwent a battery of tests which proved that he was five years older. Program Library for His Minnie was sent to one of many labora- NORTH STAR * COMPUTERS tories where highly skilled technicians $500 - ONE TIME FEE made new program chips and inserted the Get ALL the programs we write or update FREE for life! chips in the Minnie to replace the ones Includes many business application programs (Osburne & which had served Twombly well for five Associates), utilities, public domain programs, and modifications years. It was late afternoon when Twombly to North Star Extended Basic that allow appending as an execu- left; an hour after that, one of the techni- table statement and the addition of 8" floppy disks drives to cians approached the lab chief with an your present North Star System. (Hard disk units to be available almost microscopic program chip in the in near future). Call or write for free copy of Micro Mike's palm of his hand. Program Library Newsletter. "We have a condition red, I think," he Complete Business North Star told the chief. This is the alternate program Systems entertainment chip from Twombly's with modem connection Owners Minnie." to our Program Library move up to "Carson," said the chief, "that simply cannot be. He couldn't get out of the 1. Horizon Il Computer 8" Floppy Disks 2. 32KRAM building without a full complement of Completely compatible with 3. ADM -3A Terminal chips; the master computer wouldn't let your present system. Includes 4. IP -125 Printer him through the door." all software necessary to 5. DC Hayes Modem Board Carson, his face almost as red as the little run your present programs on 6. All Connectors Et Cables on pro- either 8" or 5'/e" drives or both. dot the chip which meant alternate $4995.00 gram, said: He had a full complement

st drive & controller of chips. I got the wrong one in. He got an Expandable anytime by $995 experimental chip I was designing for my addition of 8" drives. $795 each additional drive wife's Minnie." Micro Mike's "What kind of an experimental chip ?" 905 Buchanan, Amarillo, Texas 79101 asked the chief in tones that made Carson's 806 -372 -3633 flesh creep. "You might call it a babysitting chip," said the technician, "although it doesn't

just sit. I can tell you that we're in a great deal of trouble if he activates that chip. We have to prevent that." KIMSI "Condition red," sighed the chief. We have to key into his Minnie by way of the house computer, but we'll have to get authorization from Washington. I'II notify Harris; it's his problem. He won't like it much." "I don't think we have time. He'll most likely activate the entertainment chip after he finishes dinner; Twombly is predictable."

We have to take time. After that J E The KIM to S -100 bus Lewyt scandal, where the untouchability Interface /Motherboard of our beloved director was found wanting, we've been under very rigid orders about Combines the power of the 6502 with the flexibility of the S -100 bus invading the privacy of private computers. Attaches to any unmodified KIM We've got to get authorization." Complete interface logic and fully buffered motherboard They got it after a three hour delay, but in one unit On -board regulation of power for KIM as Carson feared, it was too late. When the Eight slots of S -100 compatibility for additional RAM, special code got them access to thé Video and I/O boards, PROM Programmers, Speech Twombly house computer, it reported that processors... Includes all parts, sockets for ICs, one 100 pin connector, Twombly had activated the alternate pro- and full Assembly /Operating documentation gram entertainment chip. The chief sighed and requested a complete readout from the Kit $125, Assembled $165 time of activation. All units shipped from stock FORETHOUGHT PRODUCTS CHIP ACTIVATED 2030 HOURS. SEQUENCE COMPLETED: UNDRESSING, BATHING, F 87070 Dukhobar Rd. # DRYING, POWDERING, DIAPERING. AS Eugene, Oregon 97402 _J INSTRUCTED BABY HAS BEEN PUT TO BED

WITH WARM BOTTLE. BURPING TO TAKE PLACE ON COMPLETION OF FEEDING. ESTIMATED TIME: THREE MINUTES FROM NOW.

"We can do without the burping," yelled the chief. "Carson, override the program at once; switch off the alternate program. My

God, I think we have a law suit on our hands. You and I will end up in the coal mines."

"Program is off, chief. I'll see if I can get an informal but detailed report from his Minnie... it's coming now." Chief of Laboratory Q, George Justine, had chewed the nails down to the quick on one hand and had started on the other when Carson leaned back in his chair and actually smiled. "Twombly started to panic when the waldos grabbed him and started to undress him, but calmed down and gave in when he couldn't stop them. He seemed to be actually enjoying the bath, and when he was put to bed with the warm bottle he slurped it down and actually cooed. He is now in a deep, peaceful sleep, and his Minnie reports that his blood pressure is normal for the first time in months." "Well, we're not off the hook yet, but it looks better." "Chief, we'll call him in tomorrow and explain the mistake, and apologize. We'll give him back his entertainment chip and I'll take back the babysitter chip." SMOKE SIGNAL BROADCASTING'S

"I doubt it. I mean, we can call him in, but something tells me he isn't going to give LFD-68-2 up that chip. It fits in too well with his psychological profile. We'll have to give it to Dual 8 Inch Floppy Disk System him in addition to the entertainment chip.

We'll gain one thing; I think we can get LFD-68-1 $1395.00 him to take the newer model Minnie, be- L F D-68-2 $1895.00 cause the one he has doesn't have room for any more alternate programs. If he wants to play baby, he'll have to exchange Minnies,

and I think he will."

"I hate to lose that babysitter chip; I put a lot of work in on that." "Carson, that's going to be the least of your worries. We're going to have to fill FEATURES: out lots of reports... you are. There'll be SS -50 Bus Compatible lots of investigations and an awful lot 500K Bytes of Online Storage of flack. There is one possible ray of light: Expandable to 1 Megabyte there may be other people like Twombly, Completely Software Compatible with Existing BFD -68 Systems and this may prove to be some kind of Mini -Disk

legitimate therapy. I don't know. That's Users that require at least 500K of online data storage will find the LFD -68 floppy system fits the bill. This system uses for the psychologists to decide. Right now standard 8 inch floppies to provide this increased capability. we have to get ready for the worst, charges The controller provides the capability of supporting up to four of invasion of Twombly's privacy. We 8 inch drives for a maximum system capacity of over 1 megabyte of online storage. This system is complete with system We panicked. went to the top to get software and available in two configurations. The LFD -68 -1, authorization to enter the computer of a a one drive system or the LFD -68 -2, a two drive system. private citizen, citing clear and present danger. What did we achieve? We stopped SMOG SIGNAL BROADCASTING a man from getting burped. " 6304 Yucca /Hollywood. CA 90028/(213) 462.5652

Circle 320 on inquiry card. December 1978 BYTE Publications Inc 191 The Frill -Size Floppy Disk OeskTopWoodeps Drive System Introductory Price of $1,995 (List Price $2,495) Fully Assembled and Tested Commander Two full -size 8" Shugart drives Power supply, interface, cables, cooling fan, strong aluminum chassis, attractive wood cabinetry. in Chief Controller with Western Digital 17718 controller chip and on board prom boot strap loader for CP /M "', which is the disk operating system Software recommended and available separately from EAS including assembler, text editor and debugger, and EAS's I/O A Game for the TI -58 handlers (BIOS) together with powerful utilities. Available with or without con- Programmable troller. Capable of formatting diskettes Calculator 90 day parts and workmanship warranty. S -100, Z -80, 8080 compatible. Larry Kollar Storage capacity is a quarter of a million bytes per drive, a total of a W Wadsworth Hall half a million bytes per system Room 225 Shugart drives used in our systems have the most mechanical Michigan Technological University reliability of any flexible disk drives on the market. Houghton Ml 49931 Dealer inquiries are invited.

Commander in Chief is a TI -58 snowball war game for one player (see listing 1). Electro Analytic Systems, Inc. After entering the program, press E. This PO Box 102 Ledgewood, NU 07852 clears the memory and initializes the random Phone: (201) 584 -8284 number generator (program 15 in the library CP /M' is a trademark of Digital Research, Inc. module). You are now ready to play. Enter the number of snowballs you want up to 100 and push A. If you try to enter more than 100 snowballs, the program will place only 100 snowballs in your register. No iceballs allowed. After a few seconds, the calculator will NOT A KIT come back with a 1 or a flashing 1. If the 8v015A, 5A, ± 16vit 3A power Rack mountable display flashes, you are at war. Next, you 15 slot motherboard estimate how many snowballs the enemy Card cage has and push B. The display will flash how Fan, line cord, fuse, many snowballs the enemy actually has. switch, EMI filter Following this, it will display a 1, 0 or -1 Desk top version option, 8v00A, ±16vrt10A option and then the year number; or the display voltage monitor option Rack will flash 9.9999999 99. If this occurs, 100 pin connectors optional mounted there has been a holocaust and the enemy model From is rendered inoperative. If there is no holo- S200 caust, the 1, 0 or -1 tells you whether you have won, achieved a standoff, or lost; then the year number is displayed. You and your Desk top model enemy have lost half of your snowballs and From $235 each of you will add more on the next year. If there is no war at all during the year, Write or call for a copy of our you have the option of declaring war. The detailed brochure which includes procedure is the same as that in which the enemy has declared war. If you can make it our application note through ten years, you win the Snobel Peace Prize. BUILDING CHEAP COMPUTERS. ACKNOWLEDGEMENTS INf EGRAND "Commander in Chief," The Pocket Calculator 8474 Ave 296 Visalia. CA 93277 (209) 733 9288 Game Book, Schlossberg and Brockman, Bantam Books, 1976. We accept BankAmericard /Visa and Master Charge Thanks to David Nahakian for helping me with some of the program sequences.

192 December 19780 BYTE Publications Inc Circle 179 on inquiry card. Sample Game

Your Total Total Enemy Year Snowballs Snowballs (not seen)

1 100 68 (No war, go on to the next year) 2 180 127 (No war) 3 260 209

(Enemy declares war. Player estimates 191 snowballs, an error of 18. This is multiplied by the actual enemy snowballs and the number of his snowballs. The resulting holocaust factor is 978,120. The holocaust factor needed to cause a holocaust is 1,500,000. There has been no holocaust, so each power loses half his /her snowballs, discarding fractions. Player wins.)

4 130 104 (No war) 5 230 197 (No war) 6 330 224

(Player declares war and estimates 251 enemy snowballs, an error of 27. The holocaust factor is 1,995,840. There has been a holocaust; and both sides are blitzed.

Loc. Keys Commentary Listing 1: Commander in Chief, a game for the 000 \\ Random number generator. ( Pgm J Texas Instruments TI -58 006 R/S ) (*Lb' programmable calculator.

012 100 is maximum number of snowballs Note that some of the CD operations of this TI calcu- 018 ) added is one turn. (*Lbl C lator series allow multikey 024 ( STO) ( 10 ) Lower limit entries into one location. 027 ( STO1 Upper limit This is indicated by an Add enemy snowballs asterisk within the key. 032 (*Pgm ( C ) 038 ( STO ) ( 1 1 ) 042 ( STO ) ( 20 ) 046 (RCL) ( 20 ) War ? 051 (*Lbl ) (sUM) 057 RCL ) ( R /S) 063 RCL ) (*Pause) C) Enemy snowballs flash 068 (RCL ) ( 00 Holocaust factor (RCL 077 OSTO ) 079 Maximum holocaust factor 0 ) ( 0 ) ( 0 ) C ) 086 (RCL) (RCL) 092 0 (STO 098 (RCL) O 104 (STO ) 110 O 111 ( *Op ) ( 10 ) Signum function (Who won ?) 113 ('Pause) (Pause) ( RCL) ® (GTO) 119 (CLR ) (RCL Flash year number ( R/S ) 127 (CLR) You are rendered inoperative!

December 19780 BYTE Publications Inc 193 FORTRAN and Its Generalizations

W Douglas Maurer Room 634 It really is a necessary part of your knowledge, even if you're never going to University Library Building write FORTRAN programs. George Washington University Washington DC 20052

I he average small system user will not be one has to write, in assembly language, able to use FORTRAN as a programming something like "load i; multiply by j; sub- language tor his or her system. Some small tract i; add j; divide by n; store in k" in systems have BASIC, and there is at least order to calculate the new value of k. On one FORTRAN system for the 8080 (avail- most small systems, the job is even harder able from Microsoft), but FORTRAN is than this. We have to call subroutines for still chiefly a language for large computers multiplication and division, and in an 8080 (including minicomputers and mid -size com- based system, even addition and subtrac- puters). Nevertheless, there are many situ- tion of quantities in memory cannot be ations in which a knowledge of FORTRAN done directly: the right addresses have to be is important even to the small system user. loaded into H and L first. However, when

I he most important of these is in the de- we are describing an algorithm, rather than scription of algorithms. It is of no use to writing a program, the formula above is describe an algorithm in, say, INTEL 8080 what interests us, and we would like to assembly language, since this would not write it directly. In FORTRAN, we would make sense to users of Motorola and other write microcomputers; so algorithms are very often described either in FORTRAN, or in K = (11-1+J )/N some other algebraic language. FORTRAN, though, seems to be the one that is used There are several differences between the most often for this purpose, since more FORTRAN version and the original formula. people know FORTRAN than any other Some of them are due to the fact that we algebraic language. have to be able to key the FORTRAN

I here aie hundreds of books on FOR- formula into a system on a terminal or a RAN today, all of which are written for keypunch. For instance, we have to use the large system user who is, presumably, upper case letters instead of lower case and actually going to use FOR FRAN to solve we have to use the slash (/) to mean problems. It is very rare that one finds a "divide." The parentheses are necessary desci iption of FORTRAN w-`.tten for those because, if we did not use them, that is, if who merely need to understand algorithms we wrote written in FORTRAN, but who are going to rewi ite those algorithms in some other K = I* J-I+J/N language themselves. The present article is written to fill this need. the formula we would be expressing would I he basic function of an algebraic lan- actually be guage, of course, is to allow one to write algebraic expressions directly. Given a k = formula like

since division takes precedence over k addition.

194 Ueummer 1975 b1 I L Yubl,euUn In, The last difference between the formula statements in a program, but only one END and its FORTRAN version is in the use of statement. the asterisk ( *). This is necessary whenever (5) READ. A READ statement in we have a multiplication, since IJ, just as in FORTRAN is largely self-explanatory; thus assembly languages, would be the name of a READ (5, 91) N, A, B reads in three quan- single variable. In FORTRAN, the name of a tities and calls them N, A, and B. The 5 in variable must start with a letter, can contain this statement is a FORTRAN convention: only letters and digits (although some the standard input medium (as opposed to versions of FORTRAN allow a few extra any special tapes or disk files which might characters, most do not), and has a maxi- be used) is referred to as unit number 5. mum length which depends on the system The 91 is a reference to a FORMAT state- being used. Typical maximum lengths for ment which describes, in this case, in what identifiers are eight characters (IBM 360 and format N, A, and B are going to be given. 370) and six characters (UNIVAC 1100 This FORMAT statement can be ignored series, DECsystem 10). by the person who is merely interested in In addition to the use of formulas of this what the algorithm does. kind, FORTRAN involves a number of other (6) WRITE. This is very much like statements which express commonly en- READ, except for one peculiar convention: countered sequences of instructions. Among when one of the quantities to be written out these are: is a constant string, then this string is found in the associated FORMAT statement, rather (1) GO TO. Where the 8080 assembly lan- than in the WRITE statement itself. An guage user writes JMP K, meaning "Jump to example should make this clear. Suppose we K," and the 6800 user writes BRA K, want to write out the sentence THERE meaning "Branch to K," the FORTRAN ARE 7 ERRORS IN THE ABOVE PRO- user writes GO TO 15, meaning "Go to GRAM. We have a count in our program statement number 15." Statements in FOR- TRAN have numbers rather than names, and the numbers have nothing to do with addresses in the machine; they can be assigned PET 2001 PET 2001 PET 2001 PET 2001 PET 2001 PET 2001 PET 2001 . m arbitrarily and do not even have to be in s o oN sequence (as they do in BASIC). ó TM (2) IF. The keypunches used by many 9 : PET m large system users do not have the charac- ö N ters <, >, 4, >, or* (although they do have DOCUMENTATION =) and FORTRAN therefore uses .LT. (less á than), .GT. (greater than), .LE. (less than or NOW! N equal), .GE. (greater than or equal), and .NE. (unequal). Thus A is less than B, "If á -0 then go to statement number 15" would be TIS m oó written in FORTRAN as oN f WORKBOOKS FOR THE COMMODORE PET 2001 ó Getting Started with Your PET WB -1 $4.00 IF (A.LT.B) GO TO 15 á Covers the fundamentals of PET BASIC: calculator 1m and program mode, data input and output, data ó FORTRAN is distinguished from BASIC representation, program storage on the cassette. ó f PET String and Array Handling WB -2 $3.95 (and ALGOL, PL /I, and various other alge- á Covers string and substring search, concatenation, braic languages) by requiring the parentheses replacement and manipulation. N after the keyword IF, and also by not PET Graphics WB -3 $4.95 ó making use of the word THEN. FORTRAN Covers use of cursor control and special graphics symbols to draw plots, histograms, and sketches. 9 also uses .EQ. (equal) in comparing, and not PET Canette I/O WB -4 $4.95 the character =, which is reserved for assign- Covers OPEN, CLOSE, string and numeric data files. ment statements involving formulas (such Miscellaneous PET Features WB -5 $3 95 Covers the clock, random number generator, upper "0 as in K = (I I +J) /N, discussed above). *J- and lowercase alphabetic characters, saving memory (3) STOP. This signals the end of an space, etc. algorithm, although a large system will not Add $1.50 for shipping and handling. TIS 9 actually stop at this statement, but will go P.O. Box 921 on to do the next job (assuming that there Los Alamos, NM 97544 Money back guarantee ó are more jobs waiting to be done). (4) END. This is simply the last statement in a program and has nothing to do Pet is a trade mark of Commodore Business Machines Pl with stopping, which can happen at any w 0. time. That is, we can have several STOP PET 2001 PET 2001 PET 2001 PET 2001 PET 2001 PET 2001 PET 2001

ONLY PROGRAMMERS called NERRS, which is, in this case, equal to 7. We would like to write a statement SHOULD BE something like ALLOWED TO SORT! WRITE "THERE ARE ", NERRS, " ERRORS IN THE ABOVE PROGRAM ". Isn't that ridiculous? They're your files, your information and your needs. Take control of them now In FORTRAN, however, we have to write with something like SORT-80 WRITE (6, 92) NERRS available separately (for only $95.00) or as part of where statement number 92, the FORMAT FMS -80, the only fully integrated microcomputer statement, is File Management System. From initial file defini- 92 FORMAT (' THERE ARE ', 13, tion through selective report generation, FMS -80 ' ERRORS IN THE ABOVE PROGRAM'). takes you every step of the way interactively. The 13 here is the format for NERRS (a Also ask about REMOTE -80 Intelligent Terminal three digit integer), while the 6 in the Software; SCREEN DESIGNER -interactively WRITE statement is like the 5 in the pre- create and utilize video forms; and MLU -the ceding READ statement; that is, unit num- complete Mailing List Utility. All run under any ber 6 is the standard output medium. CP /M -based system (IMDOS, CDOS, etc.). Where constant strings are not present, BASIC interfaces implemented for most through WRITE is very much like READ. That is, CALL, and all have unique benefits. we can have a statement WRITE (6, 93) DEALERS: Have we got a deal for you! Liberal N,A,B which will write out the quantities packages discounts and painless evaluation - N, A, and B. In some versions of FORTRAN, we're waiting to hear from you. we find PRINT 93,N,A,B with the unit COMPUTERS PLUS, INC. number 6 left out; the only thing to remem- 678 S. Pickett St. ber here is that we are not printing out the Alexandria, VA 22304. (703) 751 -5656 number 93, as this is the FORMAT statement number, just as before. (7) DO. Suppose we want to repeat a group of statements N times. Then, just CATCH THE before these statements, we can write

S -100 BUS DO 25 I = 1, N Q LIST SPECIAL PRICE CASH PRICE Tarbell Floppy where the last statement in the group to be Disk Controller Kit 1900° 15995 repeated has statement number 25. This will Percom Cassette not only cause the statements to be repeated, 8995 Interface Kit 7495 but will set the index I to a different value Mullen Extender Board each time: 1 the first time, 2 the second time, and so on up through N the last time. with Probe Kit 3500 29°° (8) CALL. The FORTRAN programmer SSM VBI -B can write CALL SUB, just like the 8080 Video Kit 14995 11995 programmer (the 6800 programmer would Godbout Econoram write JSR SUB, meaning "Jump to sub- IC8K Kit (Static) 1350° 11 495 routine SUB "); the difference arises when the subroutine SUB has parameters. Where IMC MB -1 12 the small system user has to figure out his Slot Motherboard -Bare 690° 4495 own way of passing parameters, FORTRAN North Star Horizon does this automatically. If the parameters 1 Kit 159900 13390o are A, B, and C, for example, the FORTRAN Check Our Prices on programmer simply writes CALL SUB(A, North Star, Vector Graphic, Cromemco, B, C). Solid State Music, TDL, Mullen. (9) SUBROUTINE. At the beginning of Quantities Limited. Shipping and Insurance Extra. every subroutine there is a statement like Prices Quoted Include Cash Discounts. SUBROUTINE SUB(X, Y, Z), which says BUS...5 that the name of this subroutine is SUB and - 1 Ci c that its dummy parameters (sometimes Address...7 White Place called formal parameters) are X, Y, and Z. Clark, N.J. 07066 This means that if SUB is now called as is, I nterface...201- 382 -1318 above (that with the statement CALL SUB(A, B, C)), then X corresponds to A,

196 December 1978 0 BYTE Publications Inc Circle 316 on inquiry card. Circle 294 on inquiry card. Y corresponds to B, and Z corresponds to C. (10) RETURN. This is used in a sub- 1IPI5 routine in place of STOP; it stops the sub- 8K STATIC RAM routine and returns to the program (which DIGITAL ASSEMBLED could possibly be another subroutine) which S -100 called this subroutine. If we use STOP in RELIABILITY a subroutine, the entire job will stop. QUALITY 1:, (11) FUNCTION. In FORTRAN there a are certain special functions: SQRT (square DEPENDABILITY SIN (sine), COS (cosine), and the root), TWO INDEPENDENT 4K BLOCKS SELECTED like. Thus the FORTRAN statement Y = ADDRESSING BY PLUGGABLE JUMPERS AT BOARD EDGE ONBOARD SWITCH WRITE PROTECTSAJFPROTECTS ALL8K SQRT(A) sets Y equal to the square root PROTECT OR EACH 41( BLOCK CAN BE PROTECTED VN FRONTPANEL also ALL S100 BUS LNES ARE FLLLY BUFFERED of A. But FORTRAN allows the pro- BUFFERING ONE LS-17L LOAD PER LNE

grammer to make up his own functions. 21L02 RAMS - TIC BKRS TYPICALLY REOURES 1 5 AMPS LOW POWER ATB VOLTS - 4 ONBOARD 5 VOLT REGULATORS These are coded like subroutines, with two 0, 1, OR 2 WAIT STATES MAY BE SELECTED WAIT STATES MA A PLUGGABLE JUMPER exceptions. We start a function with a THE BOAT) IS (LASS EPDXY WITH SILS SCREEN LEGEND, statement like FUNCTION F(X, Y, Z) QUALITY FULL SOLDER MASKS ON BOTH SEES FLOW SOL CEP/JO CCU CONTACTS which tells us that F is the name of the IF NOT SATISFIED RETURN THE UEAMAGED 5545 WITHN GUARANTEE E DAYS FOR FILL REFLFE - ALSO W DAY LMITED WARRANTY

function and X, Y, and Z are the dummy STOCK TO a0 DAYS CALL BETWEEN 830 Aro no TO RESERVE DELIVERY YOUR SIRS OR FOR PADRE !FORMATION parameters. At the end of the function MEMORY DISABLE IS IMPLEMENTED VIA PHANTOM (PIN 671 (normally just before RETURN) we write PHANTOM COMPETE TESTNG NOT OFLY OF ALL MEMORY CELLS BUT ALSO F = e, where e stands for whatever we want TESTING OF ALL SUPPORT CIRCUITRY AN) OPTIONS the value of the function to be. If we then INTRODUCTORY 450 n 250 ns use the function F by U = F(A, B, PRICE writing SPECIAL ASSEMBLED /TESTED $14995 $18995 C), then, just as before, X corresponds to CALIFORNIA RESIDENTS ADD 6% TAX A, Y corresponds to B, Z corresponds to (714) 992- 5540 C, and e will now be computed and U will 2555 E CHAPMAN AVE. be set equal to e. SUITE 604 (12) DIMENSION. This is used to define FULLERTON, CA 92631 tables (arrays). DIMENSION A(50), for example, defines a table of 50 variables which are called A(1), A(2), and so on up ATTENTION COMMODORE PET' OWNERS through A(50). We can also, of course, make reference to A(I), A(J +1), and the like. sloo DIMENSION B(3, 3) defines a matrix of UH

nine variables, B(1, 1) through B(3, 3), PERIPHERALS ADAPTER) (MEMORY and we can make reference to B(I, J) if IN ELECTRONICS awAwv TMs PETS RC.

and J have values 1, 2, or 3. AN S -100 BUS ADAPTER FOR THE COMMODORE PET` PLUGS INTO ANY 5 -100 BUS MAINFRAME - ' ""' ,-.- (13) REAL. Most large systems, of course, CONNECTS TO PET VIA RIBBON CABLE (PROVIDED) FULL S -100 BUS EMULATION

I 0I I I have floating point representations for real USE DMA DEVICES UKE CROMEMCO DAZZLER' t II ' ° ,I EXPAND THE PETS MEMORY 8 I/O FORTRAN assumes MEETS PROPOSED IEEE 5 -100 BUS SPECS , numbers. that every 1 'III II 1 l I I EASY TO ASSEMBLE -SOLDER MASK, LEGEND 8 SOCKETS Y. f variable represents a real number unless its 5199.95 KIT, 5279.95 ASSM. & TESTED + 5.00 SHIPPING. e 4 - H. {

name begins with I, J, K, L, M, or N, and The S100 MPA was the FIRST and is shill ha BE ST S.100 Bus Adaplm on lh marllel. This well thought out board actuapy meets IM proposed IEEE speoñcahas lathe S-100 Buswhch inures carpaltliky la the wet range al SIDO Bus perpwrala Now you even this rule can be overridden by a REAL ran easily expend your PET. men., and LO capebibes. THE 5.100 MPA CAN ALSO BE A SlAND ALONE 6502 CPU BOARD FOR THE 5.100 BUS statement. Thus specifies REAL LAMBDA WA, the adlean al a 6502 clip and a law other companenS IM 5.100 MPA bermes a stanóala a CPU board la the S-100 Bus -tile aay one Io otler such mrrplele opmpatabaty. Just order Ne Stand -Ala. Option Kn la an adanonal 549.95. LAMBDA to represent a real number, even though its name begins with L. OTHER HUH ELECTRONICS ACCESSORIES FOR YOUR COMMODORE PET Ths BEEPER- Automadcaly beeps when cassette LOADS and SPIES are completed. Also can beep under (14) INTEGER. The INTEGER statement progam control Just 524.95 + 2.00 slsppng Fully assembled and tested The PETUNA -Music Board that is actually an 8-bit DAC. Our software makes ìt play up to lour notes at once. allows us to define variables whose names do Software included External amp and speaker required. Just 529.95 . 2.00 shipping and handling Fully assembled and tested. not begin with I, J, K, L, M, or N to be in- Ths VDEO- Abws use of a standard monitor or TV with the PET. Great for classroom or remote viewing. tegers rather than real numbers. An integer BUFFER Designed so that MAR Enterprises SURR'MOD II pugs right on allowing use of Standard TV's. Just 52595 + 2.00 shipping and handling With SUPR'MOD II for standard TV's -559.95 + on a large system is typically 32, 36, 48, or 2.00 shlppng and handling Assembled and tested. The COMBO- A Pella and a Video Buller al on one board. You save 510.00!! 549.95 + 2.00 sfepprg and 60 bits long; an integer on a minicomputer handing-with SL1PRMOD II -57995 + ZOO shipping and handling or a midsize computer is typically 12, 16, ALL HUH ELECTRONICS PRODUCTS ARE AVAILABLE FROM STOCK FROM LEADING 18, or 24 bits long. COMPUTER STORES OR FACTORY DIRECT. CALL OR WRITE FOR MORE INFORMATION. (15) COMMON. Normally, when we have ::J1429 MAPLE STREET SAN MATEO, CA 94402 * NOW AVAILABLE: a variable in a subroutine which is called (475) 573 -7359 TRS -80 to S -100 Bus Adapter!!! J, and in (for example) another variable maserchai9e the main program (or another subroutine) DEALER INQUIRIES INVITED ELECTRONICS ; which is also called J, these are treated by FORTRAN as two different variables. The

Circle 172 on inquiry card. December 19780 BYTE Publications Inc 197 Circle 321 on inquiry card.

n n n n n Available for Immediate Delivery exception to this rule occurs when J appears in COMMON statements in both programs. uu n TRS -80 OWNERS The rules for writing COMMON statements A n properly are complex; but in a published n SOFTWARE NOW AVAILABLE program, one may always assume that the n CASSETTE OR DISC (DOS) rules have been properly followed. Every so often, one will be faced with BUSINESS - Complete small business, inventory control, invoicing, accounts receivable, accounts payable, a program written in some algebraic language general ledger, mailing list, payroll. other than FORTRAN, such as ALGOL or n PL /I. The main differences between these GAMES - Exciting new games to make your TRS -80 u more fun. languages are as follows: n HOME - Complete home budget, checkbook, savings, (1) GO TO. Statements in FORTRAN and loans. BASIC have numbers, but statements in n n ALGOL and PL /I have names. When a name n OVER 100 EXCITING PROGRAMS tt -MORE ADDED EVERY DAY- is defined is followed by a colon. n it (2) IF. Most algebraic languages other p EDUCATION - ELECTRONICS - MARKETING PROGRAMS FOR PET AND APPLE than FORTRAN use the additional keyword

Level I BASIC and Level II BASIC THEN, and many also allow the keyword (Level II available on disc) ELSE (meaning "otherwise "). Thus IF a p Choose printer option on many programs tt Custom programs available THEN Q ELSE y means "If a is true, then tt We also purchase original programs do the statement(s) p; otherwise, do the SEND FOR A COMPLETE LIST OF PROGRAMS NOW! u statement(s) y."

LE (3) STOP. ALGOL does not have a tt 80 SOFTWARE STOP statement; to stop in the middle of 25469 Hardt Street, Loma Linda, CA 92354 a program, one writes GO TO a, where is n a (714) 962 -3423 a label (followed by a colon) just before n END at the end of a program. tttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttt (4) END. In ALGOL and PL /I there are two kinds of END. One is used just as in FORTRAN, and the other is in the middle $1195 of a program paired with BEGIN. The statements between BEGIN and END are called a block (or sometimes a compound statement), and may take the place of a single statement wherever one can legally occur in the language. PL /I also requires an END U.S. ROBOTICS TELETYPE SERIES MODEMS -300 MODEL 43 paired with each DO. 300 BAUD 103/113 COMPATIBLE 10 OR 30 CHAR /SEC (5) READ. PL /I has two kinds of READ, ACOUSTIC /HARDWIRE VERSIONS 132 COLUMNS one called READ and the other called GET. ORIGINATE /ANSWER VERSIONS UPPER /LOWER CASE The GET variation is used when built -in U.S. Robotics now combines the price /performance leader in 300 Baud Modems format conversions are to be exercised. with the price /performance leader in hardcopy terminals to bring you teleprinter capability at incredible package prices. Some variations of GET involve no 10 at USR310 Originate Acoustic Coupler + Teletype Model 43 KSR = S1195 all, causing conversions in memory. ALGOL, USR330 Originate /AutoAnswer FCC Certified Modem as it was originally defined, has no input + Teletype Model 43 KSR = S1365

USR -320 AutoAnswer FCC Certified Modem + Teletype Model 43 RO = S1215 statements at all, but many ALGOL pro- Stand alone modems and teletype available: grammers assume that there is a subroutine Teletype 43 KSR with RS232C S 1095 called inreal(x), which inputs the real num- USR -310 Originate Acoustic Coupler (Operates with any standard telephone) S139 ber x, and similarly ininteger(x), which in- Direct' Telco' puts the integer x. Connect OAA Style Style (6) WRITE. PL /l uses WRITE as well as USR330 Originate /Auto-Answer Modem S324 S185 another form called PUT. WRITE corres- USR320 Auto -Answer Modem S299 S160 Certified Package. Connection to phone lines via standard extension phone ponds to READ and PUT corresponds to jack.) GET. ALGOL has outreal(x) and outin- l'Connection to phone lines via CBS-1001F OAA which can be leased from phone company for approximately S5.00 /mo. plus installation fee.) teger(x) to correspond to inreal(x) and Interfaces for stand alone modems: ininteger(x). USR310 RS232C only - (7) DO. In PL /1, in order to repeat USR320 and USR330 - RS232C and 20 ma. (Specify with order. If both interfaces are required. add S10 to unit price.) certain statements from 1 = 1 to N, we All products include a 90 day warranty and optional annual maintenancs package. Add I % I 1 shipping and handling in the continental U.S. write DO = TO N (note the word TO), Illinois residents add 5% Tax. followed by the statements to be executed, U.S. ROBOTICS, INC. followed by END. In ALGOL, we write 2440 N. Lincoln /Chicago, IL 60614/(312) 528 -9045

for 1: =1 step 1 until N do begin, followed

.. ,rr11 by the statements, followed by end; if there d, is only one statement to be repeated, then begin and end are not necessary (although al tr they may appear). In BASIC, we write ,. , . , p'r `M` FOR 1 =1 TO N, followed by the statements, t followed by NEXT I. (8) CALL. In BASIC we write GOSUBn, meaning "Go to a subroutine at statement number n "; subroutines in BASIC do not have names as they do in FORTRAN, <), Terminal® The Retro ALGOL, and PL /I. In ALGOL, we leave out raphtcs PC card mounts easily in the Lear Siegler the word CALL; thus SUB(A, B, C) by ADM -3A to provide you with an affordable graph - itself is a statement which calls the sub- ics computer termi nal. routine SUB. Features: (9) SUBROUTINE. Subroutines in Z -80 Based Point Plotting ALGOL and PL /I are called procedures, 512 by 250 Automatic Vector and where in FORTRAN one would write Dot Matrix Generation SUBROUTINE SUB(X, Y, Z), in ALGOL Simple Plug -in Optional TEKTRONIX one writes procedure SUB(X, Y, Z), and in Interconnect Software Compatibility PL/I one writes SUB: PROCEDURE(X, You will be impressed with the packaging, per- Y, Z). The situation in ALGOL is especially formance and price of the Retro- Graphics card. confusing because a subroutine is written Write or phone today for complete specifica- inside the program of which it is a sub- tions. routine, at the beginning of that program DIGITAL RESEARCH & ENGINEERING with all the other declarations (real, integer, 5223 Glide Drive Davis, CA 95616 and the like). This makes it very difficult, (916) 756 -8055 in practice, to figure out where the first Dumb Terminal is a registered trademark of Lear Siegler Inc. statement of an ALGOL main program is, particularly if it has a lot of nested subroutines. You have to start at the beginning of the program and work your way through all the subroutines, each of which is declared by a procedure statement with a matching end (which you have to find); then you suddenly come, with no warning, upon a simple statement like is =1 and, believe it or not, that is where you are supposed to start executing. (10) RETURN. In PL /I you write RETURN(e) to correspond to F =e followed by RETURN in FORTRAN, where F is the name of a function. (11) FUNCTION. The terms correspond- BET, ing to the FORTRAN FUNCTION for ALGOL and PL /I are INTEGER PROCE- DURE, REAL PROCEDURE, and the UOU DIDN T KNOW! /*Pa Pending like; the adjective before PROCEDURE OAE'S new PP- 2708/16 tells you whether the value of the function PROM Programmer is the only programmer with all turn cermet trimmers (for is supposed to be an integer, a real number, precision pulse width and these features: amplitude alignment) Converts a PROM memory or whatever. All packaged in a handsome socket to a table top pro- aluminum case (12) DIMENSION. In BASIC, one writes grammer: No complex inter- DIM instead of DIMENSION. In ALGOL, facing to wire -just plug it PP- 2708/16 ..A & T $295. into a 2708 memory socket' one writes integer array or real array; in A short subroutine sends PP -2716 (Programs Intel's PL /I, one writes DECLARE, which may be data over the address lines 2716) A & T $295. to program the PROM shortened to DCL (and usually is). DE- Programs 2 PROMS for less CLARE in PL /I is an all- purpose declaration than the cost of a personality module. (2708s and TMS having dozens of variations, but DECLARE 2716s) Connect 2 or more in paral- A(100), sometimes followed by various lel for - super production Oliver Advanced Engineering, Inc. other keywords, is roughly like DIMENSION programming 676 West Wilson Avenue Complete with DC to DC as is Glendale, Calif. 91203 A(100) in FORTRAN, real array switching invertor and 10 (213) 240 -0080

SUPERKIM A[1:1001 in ALGOL (the 1 here is the MICROPRODUCTS HAS THEM lower bound on subscripts, which may be MICROPRODUCTS announces Superkim. capacitor Superkim has eight latched arbitrary in ALGOL, although it is always 1 its new singleboard control computer for priority interrupts which are individ- commercial. industrial and hobbyist uses. ually resettable under software control. in FORTRAN). Superkim can accommodate 4K RAM and This feature is absolutely essential for 16K EPROM onboard implementing highly useful real time (13) REAL. In the REAL systems ALGOL, This super controller can be applied to any as a situation where intelligent control is MICROPRODUCTScan supply a hardware attribute refers to representation float- desirable: such as any manufacturing or interlace and a software downloading production line process where automa- routine for the APPLE II and a firmware ing point number. ¡Note that the attribute tion is possible or to automatic tool receiver routine, located in a 2716 EPROM. operation or to real time data collection. for installation in the Superkim. This F LOAT performs this function in PLII, and The board has a large prototype area greatly facilitates software development suitable for mounting Analog to Digital. for the Superkim because of the powerful that REAL in PL /l is used only to distin- Digital to Analog converters, relays and MICROPRODUCTS/APPLE II Co- resident other interface devices. assembler. the MICROPRODUCTS/ guish real from complex numbers. ..BL] APPLE II to PR -40 interface and the large Superkim is totally compatible with all memory available in the APPLE II. The (14) INTEGER. BASIC assumes that all KIM -1' software and most KIM -1 and software can be instantaneously trans- from II APPLE II hardware interfaces. It has TTY. mitted your APPLE software devel- numbers are real; integers will be treated as RS232 and audio cassette interfaces as opment system to your Superkim RAM for well as an onboard 5 volt. 3 amp and 12 instant checkout and use. if they are real numbers, which usually volt regulator. rectifier diodes and filter 'KIM -1 a a product of MOS Technology works the way we want it to, although some operations like division must be watched carefully. In ALGOL, all integers must ap- APPLE 11 pear in integer statements. DEVICES BY MICROPRODUCTS (1s) COMMON. In PL /I, all main

MICROPRODUCTS /APPLE II PR -4Oand Centronics Interface 49.95 routine variables are common (called MICROPRODUCTS/APPLE 118-be parallel output portcard ...44.95 "global" in PL /I parlance) to internal sub-

MICROPRODUCTS /APPLE II co- residentasserroferoncassette . 19.95 routines (ie: the subroutine is declared by a MICROPRODUCTS /APPLE II co- resident assembler onnappyüsc 25.00 MICROPRODUCTS /APPLE II EPROM programmer 99.95 PROCEDURE statement within the MICROPRODUCTS /APPLE 115 volt EPROM sodrel edepler .. .. 14.95 boundaries of the calling PROCEDURE and

MICROPRODUCTS /APPLE Ilmodem . 129.95 its END) unless is redefined in the sub- MI CROP RODUCTSSuperkim single board control computer 395.00 it MICROPRODUCTS 16cnaracteralphanumericLCD 795.00 routine. The EXTERNAL attribute is used MICROPRODUCTS /KIM -1 Improved keyboard uth double sided. gold plated pc board 30.00 to share variables between external pro- MICROPRODUCTS cedures. In ALGOL, any variable in a main Dealer inquiries invited 2107 Artesia Blvd. / Redondo Beach / CA 90278 program may automatically be used in any residents add 6% sales tae 12 131 37 4 -16 73 of its subroutines, unless there is another variable declared in the given subroutine that has the same name. (16) Assignment statements. In ALGOL, the symbol := is used where = is used in Why FORTRAN, BASIC, and PL /I. In addition, = is used where .EQ. is used in FORTRAN. Some versions of BASIC permit, and some Pay require, the word LET at the beginning of More? every assignment statement. Why pay for more printer than you need? Our (17) Semicolons. Every statement in series 40 printers offer more features for less ALGOL ends with a semicolon unless it is bucks than any other commercial quality printer followed by end. Every PL /I statement is on the market today. A complete stand -alone 40 followed by a semicolon. column impact dot matrix printer with a 64 There are hundreds of other differences character ASCII set. Includes power supply, between the various algebraic languages, but casework and interface electronics. Single these are the basic ones which are required quantity price for the parallel ASCII interface to be able to read published algorithms in model is $425. Serial RS232 /current loop FORTRAN, ALGOL, BASIC, and PL /I. interface models start at $575. OEM discounts Most such algorithms, with a few notorious available. exceptions, are presented in such a way as to use only the rules described above. The For more information write to: reader whose appetite has been stimulated by the possibilities of algebraic languages MPI 2099 West might do well to supplement his small 2200 South, Salt Lake City, Utah system knowledge by renting a small amount 84119 or call (801) of time (perhaps $100 worth) on a large 973 -6053. system and trying out various features of FORTRAN, PL /I, and the like. This is, of course, in addition to the use of cross assemblers and cross compilers, which still require large systems to produce small system object code.

200 December 1978 BYTE Publications Inc Circle 265 on inquiry card. *************************** ********* * SOFTWARE NEW BASIC SOFTWARE :FROM REAL WORLD SIMULATIONS * P. O. BOX 2528 ORANGE, CA. 92669 * PRO I OOTBALL HANDICAPPING PROGRAM (714) 774 -1270 41( * INCLUDES USER'S GUIDE, THEORETICAL DEVELOPMENT, SAM-

BASIC SOI I WARE * * PLE INPUT DATA AND OUTPUT. MAKE MONEY WITH YOUR NORTH STAR I RS -MO APPLI. COMPUTER 10K . * $26.00 NORTH ST A.R BASIC on diskette, ready to run. North Star I utorial I, I utoríal II, DRAW POKER SIMULATOR I utori.l III (Release 4) teaches North Star Basic, Word Processing. Accts. Payable, GARDENIA, CA. RULES (DECK INCLUDES JOKER). YOU PLAY 4( Accts. Receivable, Payroll, General Ledger, Medical /1'ml. Accts., Rec. Billing, AGAINST UP TO SIX OTHER PLAYERS CONTROLLED BY THE Inventory, Sales Analysis, Computer Chess, Mailing Labels, Personnel System, PROGRAM. IMPROVE YOUR POKER SKI LLS. 13K $18.00 it

MANY MORE AVAILABLE. I.ACI I INDIVIDUAL SYSTEM 335.00 CHESS SCRAMBLE .4( TOTALLY INTEGRATED SYSTEM (,\ /R, A /P, GI.N. LIDGER, PAY, LL ITLR EXCITING NEW CHESS GAME FOR TWO PLAYERS AND A COM * PUTER. OF GENERATOR, BUS. STA I IS TICS) in Binder Complete Doc. $150.00 COMBINES THE LUCK ELEMENT BACKGAMMON WITH

Checkbook Bal., Budget Planner, Coll Handicapper, Game Disk, X -RA I I.0 Story CHESS SKILL AND STRATEGY. 11K S9.00

Generator. MORE AVAILABLE. LACH INDIVIDUAL SYS I LM $25.00 MODEL ROCKET /AIRPLANE PERFORMANCE SIMULATOR it A LLOWS YOU TO "FLY" YOUR MODEL DESIGN BEFORE BUILDING 41( IQ TEST, MEMORY Diagnostic, Pers. I finance, Bus. Statistics, Crypt° Encoder, IT. INCLUDES INSTRUCTIONS ON HOW TO MEASURE OR CALCU- Sign Mal.er, Menu Planner $15.00 EACH LATE ALL INPUT DATA. 10K $26.00 SINGLE or DUAL DRIVE, MK Free Memory Required. BEAM DEFLECTION AND STRESS PROGRAM ALLOWS FOR VARIABLE CROSS SECTION, ANY END CONDITIONS, TRS.80 on cassette (Level Numerous Games, Examples, STAR TREK, WUM- ' I). ELASTIC BED OR DISCRETE SUPPORTS. GREAT DESIGN AID FOR '* PUS, MORE only $3.95 EACH BOOKSHELVES, CANTILEVERED DESKS, SLAB BRIDGES, SUN * BASIC TUTORIAL (Learn Basic Programming) $9.95 DECKS, ETC. 7K $26.00 STOCK MARKET ANALYSIS $9.95 * MANY MORE. ALL PROGRAMS ARE IN NORTH STAR BASIC AND MAY BE * APPLE on Cassette. Many Games, Examples, WORLDPOWER, STARTREK, ORDERED ON DISK FOR AN ADDITIONAL S2.00. SOFTWARE BOWLING, BINGO $5.95 EACH LIBRARY SPECIAL. TAKE ANY FOUR OF THE ABOVE PROGRAMS BASIC TUTORIAL (Learn Basic) $9.95 FOR S49.00. INSTRUCTIONS ARE INCLUDED FOR CONVERSION STOCK MARKET ANALYSIS $9.95 TO OTHER BASICS. CALIFORNIA RESIDENTS PLEASE ADD 6% BUDGET PLAN $5.95 TAX. APPLE DISK BUSINESS SYSTEMS, AIR, A /P, etc. ONLY $35.00 PER SYSTEM *

Order by Phone (714) 774 -1270, UPS COD, or Mail Order Today. REAL WORLD SIMULATIONS

Over 1000 Systems Sold, Order Now . P.O. BOX 4107 SOI TWARE BOOKS SAME PRICE FOR ALL SYSTEMS TORRANCE, CA 90510 CA ":ADA: Please remit in U.S. dollars only. J * * * ** * * * * * * * * * * * * * * * * * * * * * * * * * * * * * **

HERE IS THE LATEST AND BEST IN 8080/Z80 DISK SOFTWARE

CP /MT° FDOS and Utilities From $145 Xitan Package A3+ (as keyed above) From $409 Microsoft FORTRAN -80 $400 Micro Focus CIS Cobol $500 Microsoft COBOL -80 $625 Source Disk Based Disassembler $80 Microsoft Disk Extended BASIC $300 ZASM Zilog'" Mnomonic Assembler $45 Microsoft MACRO -80 MACRO Assembler /Linking Loader $149 XY BASIC Process Control Language $300 Microsoft MACRO -80 (as above) w Subroutine Library $219 SMAL /80 Structured Macro Assembler Language $75 Microsoft EDIT -80 Line Editor $89 CBASIC Compiler /Interpreter BASIC $95 Xitan SUPER BASIC (A3) $99 MAC Macro Assembler $100 Xitan DISK BASIC (A3 +) $159 SID Symbolic Instruction Debugger $85 Xitan Z -TEL Text Editor (A3. A3 +) $69 TEX Text Formatter $85 Xitan Text Output Processor (A3. A3 +) N/A General Ledger $995 Xitan Macro ASSEMBLER A3. A3+) $69 Accounts Receivable $750 Xitan Z -BUG (A3 +) $89 NAD Name & Address Processor $79 Xitan LINKER (A3 +) $69 QSORT Disk File Sort /Merge Utility $95 Xitan Package A3 (as keyed above) $249

Most software available in a variety of diskette formats including: IBM 8" single and double density; North Star CP /M; Micropolis CP /M; and 5" soft sectored. All Lifeboat software requires CP /M to operate.

Watch for the December 1978 release of the above software on Processor Tech Helios II; Altair Disk; and iCOM Microdisk systems. Available from computer stores nationwide or order direct from: LIFEBOAT ASSOCIATES 164 W. 83rd Street New York, N.Y. 10024 (212) 580 -0082

BYTE December 1978 201 This is a reply to a statement in Mr Fylstra's article "Convert Your TV Set to a Video Monitor," which appeared in the May 1978 BYTE, page 22.

While I will not contest Mr Fylstra's Comments on the statements and arguments that the direct video entry method is definitely superior Technical to the radio frequency (RF) entry method,

I must take a stand against his statement Forum that the radio frequency entry method RF Entry Method "...is enough to display at most about 32 characters per line." Mr Fylstra has accurately identified and reported the pros and cons of the two methods, but an for Video Monitors individual reading his article and contem- plating a 64 or 80 character per line display would immediately discard the possibility of the radio frequency entry method. My Victor A Wiseman experiences should prove this to be unfair. 7960 Grand Oaks Ct When considering the options I had for Gurnee IL 60031 adding a video display to my SOL -20, I considered buying a monitor for $180, converting my television for direct entry, and using the radio frequency entry method.

Since I already had a portable television

suitable for the job, I decided against spending $180 for a monitor. This left me with the direct video and radio frequency entry

methods. I then armed myself with a Sams Photo -Fact folder and performed some exploratory surgery on my television. This

Photo 1: Author's system convinced me that I could use the direct with Processor Technology entry method, but it would require some SOL-20 computer and rear care and time to do properly. I finally view of RF entry video decided that the most expedient method display. would be the radio frequency entry method; the cost was low enough so that, if it didn't

work out, I would not have lost much. As it turned out, the radio frequency entry method proved entirely satisfactory for my

needs and I have been using it for the past year and a half.

Photo 1 shows my system. The processor 713 t;IS(t,128),IST3,211,IS(?57,1t),IS16,5121:ET is a SOL -20 which incorporates everything Ifi1,I6qS on a single printed circuit board, including the video display generator. The output of 7f0311-710 this generator is fed through the black cable 71IN etts fi1IïF Qt1PUT WORD coming from the back of the SOL and across 7118 PQi11T #2;Zf11,28),3(o,256),lir5.14i,3+33 : is a 7199 RETtJdI the back of the television. This part of 11M RF?!ets MAW FIELDS section of shielded coaxial cable supplied 11818 QIRSM R(D,3),R(D,4): BRIT ,",TS with the SOL -20 kit. It is connected to a 11101 IF LD1(TS)4 REM LET TS4f(R(D,2),R(D,2)+R(D,1)-1% small aluminum box containing a Pixe- I1.8311 LIT TS-#10f(TS,RtD,UI Verter, a battery pack of 4 AA cells, and an 110411 QR50R R(D,3),R(D,4): PRINT ß; on /off switch (hidden). The radio frequency 11164 LET QS:R(D,2),RtD,21+47(D,1)-1)=T$ output from the Pixe -Verter is fed through 1I2`A RE1A4 3D® REItzss WORD RIMS a twisted pair of solid conductor wires to 3122 DATA 1á,1 ,1,4,1,1,3,f,4,2,3,2,5,6,3,7,6,11,3,13 the small black connector on the back of / the television set. This connector was L supplied with the set and is used for connecting an external antenna. The upper binding posts are for VHF and the lower are for UHF, the switch in the center is for Photo 2: Typical display of the system. a local /distant setting (it is set for local).

202 December 1978 © BYTE Publications Inc 1976/1977 Cover Price To further improve plus postage service to our customers we and handling have installed a toll -free E STE \WATS line in our Peterborough, New Back Issues for sale Hampshire office. If you would

1IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIi like to order a The following issues available: BYTE's subscription '75 '77 '78 New BYTE, or if = September January February December February March you have a March April Toll -free April May question relat- '76 May June February June July ed to a BYTE March July August E April August September Subscriber subscription, = June September October July October November you are invited = November November December December W.A.T.S. Line to call* _ * Cover price for all issues thru August 1977 (800)258 -5485 is $1.50 plus $.25 postage and handling ($3.50 total foreign). September '77 thru between 8:00 AM and issues are plus postage = current '78 $2.00 $.50 4:30 PM Eastern Time. and handling ($4.00 total foreign). fluuuuuuuuunuuuuunuuuuuunuuuuuuunuuuunuwc (Friday 8 AM - Noon). (800) 258 -5485 *Calls from conti- Send requests with payment to :: BYTE Magazine nental U.S. 70 Main Street We thank you and look Peterborough, NH 03458 forward to serving you. only.

1 ttn: Back Issues

this publication A Message is to our Subscribers available in microFoffn From time to time we make information of interest to the BYTE subscriber list them in the mail. Used are !!!OO 11111111111111° 'MN available to other companies our subscribers' names and 0: ilailiii1Rt©®III who wish to send our addresses only (no other fii- - ®AN®-cm subscribers promotional information we may have is NEE -°aeikio©- ci®ur - material about their products. ever given). itkit We take great care to screen MIN these companies, choosing While we believe the only those who are reputable, distribution of this and whose products, services, information is of benefit to or information we feel would our subscribers, we firmly Please send me additional information. be of interest to you. Direct respect the wishes of any University Microfilms International mail is an efficient medium subscriber who does not want 300 North Zeeb Road 18 Bedford Row for presenting the latest to receive such promotional Dept. P.R. Dept. P.R. Ann Arbor, MI 48106 London, WC1 R 4EJ personal computer goods and literature. Should you wish to U.S.A. England services to our subscribers. restrict the use of your name, simply send your request to Name Many BYTE subscribers BYTE Publications Inc, Attn: Institution appreciate this controlled Circulation Department, Street use of our mailing list, and 70 Main St, Peterborough NH City look forward to finding 03458. Thank you. State Zip

BYTE Decernber 1978 203 The television itself is a Sony Model 9 -51 UW with a 9 inch (13.5 cm) diagonal screen. It is over 11 years old and well -used.

About the Photos

All photos were taken with a Leica M3 with a 50 mm F/2 dual range Summicron lens, using Tri -X ASA 400 35 mm film. The ray *,-.;V-. 1? delayed shutter release was used to dampen 'akairfghijklwaprbtaff.r effects. Photo 1 was taken with ' -mew, -.4211S1R; (_}701!#1015lt1410 vibration \. existing light from a window on a sunny 'alktie#!tt; i Lnelplrstrutrnyz4: r !'láig( )s+, -.V2366789c;(=ì?8MIEF9íIA4MPES7iA1A7N day at 1/60 second at f/5.6. Photos 2 and 3 'abciefghi fttastapgrstivatyzt:r were taken at a distance of 21 inches (53 )a+,-.41Z34543;'&4: !'Mal( ; ' =renocre6HI11nAfegrasvaya ,,s cm) at 1 /30 second at f /4. The bright dia-

'abcàef9k1 lit Iarsapgr'stuuay_, . ,' gonal bands seen on the screen are due to !'1154( )a+, -_ /1/6456789:; (=)*RB(IlfFß'I.DQH!8i giSifNiAl3 \I the discrepancy between the shutter speed, the scan rate of the television, and the focal : 'Malt )a+, -.41Z366789:; (_ )7!!79:1Ef8+I1K111ICKR57t.M4r-Z. ',l plane camera used to take abcde?gh i ji 1snoptrstwrotyz r. )' shutter of the ' $ Z ( ) a+, -. 41Z366789:; ( =>tiNCEEF9C12ttfgi5T}.M0,")} the photos. The darkening at the top of the ' abcdrrjh 1 fit lrlrsapqrstwrrx9zt t r screen, the heightening of the characters RF Ar at the top, and the slight slanting of the I characters is due to the poor vertical and horizontal linearity of the set. The slight fuzziness of the display at the left of the pictures is due to depth of field restrictions. Overall, photos 2 and 3 accurately represent Photo 3: Selected portion of the available character set, what is seen by the human eye and brain (eye persistency eliminates the bright diagonal bands). Photo 2 is a common display 6f a portion of a program listing using all upper case characters. Photo 3 is a generated display of a selected portion of the available charac- 't'ISA] ter set. Control characters were eliminated, since they would cause unwanted display functions like carriage returns and screen SUPER clearing. Photos 2 and 3 each show one or SPECiALS more lines with 64 characters each. Photo 3 is most indicative of the limita- IMSAI's New Series of Dual- Floppy Com- tions of the radio frequency entry method. puter Systems. All fully assembled. The lower case characters m and w show a Each includes 8085 processor, dual 51/4 " definite merging of the dot pattern. The floppy driver, 32K RAM, Serial and Parallel upper case versions also show this effect I/0, IMDOS software. Just add your favorite to a lesser degree. In normal use, however, terminal. the human eye and brain manage to fill in gaps in definition. Item List Cash Code Description Price Price I hope this material will show that the

IM-PCS -40 180KB Disk Storage $2695. $2291. radio frequency entry method is capable IM- PCS -42 400KB Disk Storage $2995 $2546. of producing a very satisfactory video dis- IM- PCS-44 780KB Disk Storage $3695. $3141. play of 64 characters per line. IMSAI's Great Video Data Processor Series Complete computer systems include, Keyboard 9" CRT, 32K RAM, 8085 processor,

Serial and Parallel I /O. Dual 51/." disk drives, IMDOS software.

Technical Forum is o fea- IM-VDP-40 180KB Disk Storage $4495 $3821. ture intended os an interactive IM-VDP-42 400KB Disk Storage $4695. $3991. IM-VDP-44 780KB Disk Storage $4995. $4246. dialog on the technology of personal computing. The subject matter is open -ended, and the intent is to foster discussion and communication among readers of BYTE. We ask that all correspondents supply their full names and P.O. Box 71 addresses to be printed with Fayetteville, N.Y. 13066 their commentaries.

204 December 1978 ©BYTE Publications Inc Circle 70 on inquiry card. Continued from page 6 sity of California at San Diego (UCSD) in a phone conversation this past September 20. space potential of the current 8 bit micro- This is the development of a microcomputer processors has effectively become saturated. chip set which directly executes the UCSD This saturation of memory address space Pascal compiler's p -code intermediate lan- in the 8 bit 40 pin package microprocessors guage. The firm responsible for this inno- with a mere eight parts leads to the next vation is Western Digital, 3128 Red Hill Av, new high in semiconductor technology's POB 2180, Newport Beach CA 92663. In current innovations: the testing and sub- phone conversation with Dr Larry Lotito sequent approach to volume production of Western Digital I found out some more of three excellent large scale microprocessors details about the processor, which he and which provide 23 and 24 bit address spaces Ken jokingly call a "sand casting" of the capable of reaching 8 or 16 million bytes of UCSD p -code interpreter. This first high memory (or peripheral hardware.) I refer level language machine in microprocessor of course to the new crop of 16 bit tradi- form will come to market in several forms tional microprocessors introduced by Intel, in January of 1979. Zilog and Motorola. Perhaps the first such As readers familiar with the development part was the Intel 8086 announced last of minicomputer technology into micro- spring and most likely in production by computer form will recall, Western Digital the time this is written. (From one contact was the semiconductor manufacturer which

I heard mention of an even newer 8087, designed and first supplied the chip sets for but have not seen any written information the Digital Equipment Corp (DEC) LSI -11 on such a part to date.) The second part, product several years ago. These chip sets announced shortly after the 8086 last consist of a microprogram controller and a spring, is the Zilog Z -8000. But what appeals set of read only memory programs which to my mind, after hearing engineering intro- emulate the desired computer's architecture. ductory talks on all three of these new After the first LSI -11 parts had been created products by representatives of the com- and marketed, DEC began its own in house panies, is the Motorola 68000. It is my own semiconductor fabrication efforts and personal favorite, providing a 24 bit byte Western Digital turned out to have less of a address space and a relatively simple system design concept without elaborate memory paging and address bus multiplexing requirements. It is the kind of 16 bit micropro- 16K RAM' cessor I like, namely one with a separate FULLY STATIC 24 bit byte address bus, a 16 bit bidirectional data bus and simple power supply KIT $350 requirements. If I were to build a new 10 SLOT MAINFRAME system of the homebrew variety at the TT -10 KIT 5325 10 SLOT TABLE TOP present time, it is the one I would most MICROCOMPUTERS likely use. For the moment then, the three TT-8080. . .KIT $440 processors from Intel, Zilog and Motorola SYSTEM WITH 16K & I/O are the best possibilities for overcoming TT- 8080 -S. ..K IT 51050 the address limitation problems which CARD CAGE & 1 become very real as the 64 K dynamic MOTHER BOARD memory parts come to market. ECT- 100. ..KIT 5100 The third major development of the CCMB-10. . .KIT S75 1 WITH CONNECTORS current crop of large scale integration & GUIDES technology is that of new video display ECT -100- F. ..KIT $200 controller chips. These parts are actually iìliIiiiiiíiíiítirì CCMB- 10- F.. .KIT 5125 1 in production at the present time, and are, CPU'S, MEMORY no doubt, quietly buried in the designs MOTHER BOARDS 1 of many of the personal computing pro- PROTOTYPING BOARDS EXTENDER CARDS ducts which have come to the market POWER SUPPLIES for the first time in late 1978 and those 1 which will arrive in early 1979. We've SHIPPING EXTRA DEALER INQUIRIES INVITED already received a number of articles on this kind of device, articles which readers ELECTRONIC CONTROL TECHNOLOGY 1 will see in an upcoming special issue on the IFACTORY ADDRESS: MAILING ADDRESS: theme of video graphic interfaces. 763 RAMSEY AVENUE P. O. BOX 6 HILLSIDE. N. J. The final and most exciting development 07205 UNION, N. J. 07083 (201) 686 -8080 of recent months was relayed to me by Ken Bowles of the Pascal project at the Univer- I J

Circle 120 on inquiry card. December 1978 © BYTE Publications Inc 205 16/4 +1 E PROM /RAM BOARD Z-80 SOFTWARE There is much more, including complete systems; for more S -100 Compatable Z COS 1.0 Cassette operation system information, send for our flyer. -Sockets for up to 16 2708's for the Zapple monitor a Dojen/ PCE Electronics Eprom addressable in 4K blocks Teletek UCRI. Allows cassette 4782 Dewey Drive runs save load TDL Rom at-any IK boundary a from /Xiton basic. Fair Oaks Ca. 95628 Disable/enable rom or any eprom $25.00 to 4 eprom waitstates VIDEO 1.0,2.0 Full cursor control muster charge .5% for shipping, 0 excess refunded Solder mask - silk screen video driver 64x16 (1.0) or 80x24 (2.0). visa $130- kit $155- assembled $20.00 .calif. residents ram add $5 for 250ns SPHINXMON 1.0 A complete system .phone orders add 6% sales (916)966 -2208 tax Software on Dalen /Teletek tape monitor (4K). TDL /Xitan compatible or add $5 for 8 CPM disk, send CPM interactive. $55.00 COD requires .all products mop. prices subject to chonge 50% deposit guaranteed

market for its microprocessors than might bination of Pascal compiler, editor and have been expected. disk operating system written in Pascal. The In the past two years or so, several assembler for this machine is the UCSD variations of the basic 16 bit architecture of Pascal compiler, and its "assembly language" this chip set have been offered on a custom is Pascal. basis, and at least one such variation has One of the most interesting forms in appeared in the form of an advanced S -100 which the Western Digital Pascal Micro bus computer (MCP- 1600). Of course, Engine will be made available is as an as- Western Digital has continued to supply sembled black box computer which contains standard parts for the digital systems the following hardware: the Pascal Micro markets, such as floppy disk controller Engine processor; 64 K bytes of program- chips, and serial communications interfaces, mable memory; two RS -232 serial terminal among others. With the experience of pro- ports capable of operations at up to 19,200 ducing more than one read only memory bps; two parallel ports for support of a microcode definition for the MCP -1600 printer; a floppy disk controller with direct microprocessor system design, it was not memory access which is capable of inter- hard for the firm to write the microcode facing four floppy disk drives of 8 or 5 inch needed to emulate a new design, a "P- size, single or double density; and a power engine" that executes the intermediate supply for the processor. (Users will thus language codes produced by the Pascal com- have to supply a terminal and the actual piler developed by UCSD. Western Digital floppy disk drives with their own power calls the resulting chip set the "Pascal supplies.) Given the special introductory Micro Engine" and considers this name their price of $1995 for the first 500 systems proprietary trademark. According to Larry, produced, and the $2995 price after the this product will be widely available in introductory period, this package is truly several forms in January of 1979. What is amazing. It is intended as a development significant is that the software development system for the MCP -1600 Pascal Micro system for this chip set is the UCSD Pascal Engine chip set, even though it will cer- system without any modification: a com- tainly be available through the more pro-

PET PRINTER ADAPTER

GET HARD COPY FROM YOUR The CmC ADA 1200 drives an $98.50 ADA 1200B COMMODORE PET USING A RS -232 printer from the PET Assembled and tested STANDARD RS -232 PRINTER IEEE -488 bus. Now, the PET owner can obtain hard copy $169.00 ADA 1200C listings and can type letters, With case, power supply and RS -232 connector manuscripts, mailing labels, (11 tables of data, pictures, in- Order direct or contact your local computer store voices, graphs, checks, needle- Add $3.00 for postage and handling per order. point patterns, etc., using a 1200B ' 1\ 1200C CONNECTICUT microCOMPUTER standard RS -232 printer or 150 POCONO RD, BROOK FIELD, CT 06804 terminal. (203) 7759659

YOUR 6800 BASIC BOMBING?

Try our guaranteed Basic with print using statements, renumbering with automatic revectoring, random disc files and more. (Specify Smoke Signal Broadcasting or cassette) $ 50 Editor - Text Processor with mailing lists and labels, full disc handling capabilities. (Specify Smoke Signal Broadcasting or Flex) $100 MSI version of Editor - Text Processor with custom DOS $125 Super Payroll includes initial loader, payroll, editor -text processor, 941 and unemployment compensation reports, departmental analysis, up to 10 states and 10 additional cities (or local governments), and more. (Specify Smoke Signal Broadcasting, Flex, or MSI $400

6800 Specialists Custom Programming Our Specialty Phone Hours Mondays, Wednesdays, Fridays 3 PM -5 PM AAA Chicago Computer Center Saturdays 1 PM -5 PM 3007V2 W. Waveland Avenue Calls will be answered by answering set at other times. Chicago, IL 60618 (312) 539-5833

gressive local dealers to the personal com- relative to the LSI -11 which uses very similar puter trade. hardware. Designers who are interested in Western Digital, however, considers itself creating dedicated microprocessor systems mainly a semiconductor manufacturer, so that use the most advanced and reliable one of the reasons for the relatively low software development techniques will find price on the development system's processor this chip set a natural one to use. Designers kernel is to promote sale of the chip sets for of personal computing products will also use in new designs. We can expect to see find it useful, for the extremely powerful more than one personal computer manu- UCSD Pascal software system fits naturally facturer taking advantage of this develop- into the machine. ment, for the characteristics of the directly This announcement of a high level lan- executed p -code method allow programs guage machine for Pascal is perhaps the high to run from six to eight times faster than point of the current crop of wonders which would be possible using the LSI -11 versions include the 64 K memories, large scale of the software. microprocessors and video controllers. Some In the LSI -11 version of the UCSD people have disputed the relevance of high system (or any other conventional pro- level languages like Pascal, on the ground cessor's version) there are two levels of that they demand expensive systems, but emulation. At the first level is the hardware the arrival of the relatively inexpensive needed to execute the instruction set of the Western Digital machine next month is particular microprocessor, be it 8080, perhaps the last word on that argument for LSI -11, 6800, 6502 or any other instruction now. The nature of the new levels of sophis- set. The second level comes in when the tication in the larger microprocessor chips particular microprocessor runs an interpreter such as the 8086, Z -8000 and 68000 com- which emulates the P- machine. With the plement the new heights of memory density Western Digital innovation, the P- machine in the 64 K chips and further indicate both is directly executed by the hardware which the need for and practicality of high level is seen by the system designer. This direct languages like Pascal in future personal execution is the reason for the improvement corn puters.

MONMY SEE MONKEY DO JUST LIKE A MULLEN CONTROLLER

Thanks to B opto- solotar inputs, the CB -1 Controller Board Kit (SBB) con "see' a variety of cond- tions, and pass this information along to your computer; the computer then makes app:opncne deci- sions, and tells the CB -1 what to "do." B on -board switches con ether drive low power loans cirectly. or trigger Mullen 500 Watt control modules. And what con a CB -1 dol Users report applications varying from environmental hewing systems to

automatic cat feeders . . . and we hear about more uses all the time. In fact. right now we're hear ing about lots of applications thanks to our Controller Board Applications Contest. Stop by your local computer store for details, an entry blank, and an in- person look at the CB-I If your computer would like to move up the evolutionary path and acquire appendages to go along with its intelligence, the CB -1 is the place to start.

Put your computer to work for you . . . we make it easy. MULLEN Computer Products BOX 6214, HAYWARD, CA 94545

Circle 267 on inquiry card. December 1978, BYTE Publications Inc 207 Circle 32 on inquiry card. The Independent Newsletter J)°31 of Heath Co, Computers 0

The independence of Buss is a crucial factor in opinions of a single reviewer. It shares news of its significance to users (and prospective users) compatible hardware & software from other vendors of Heath Co. computers. Information on new prod- as well as reviews of books that can help you get ucts is presented to Bus:; readers as it leaks out the most out of your computer system. of Benton Harbor, not held back to suit the plans Every issue of Buss travels by first class mail of the manufacturer. This has been true from its (outside North America it goes by air for only $2 first issue, which directed attention to the 8080 extra). Your 12 -issue subscription can be on its and LSI -11 months before any advertising appeared way to you within a week. You have the choice of on the H8 and H11. buss features candid accounts starting either with the latest issue or with all of owners' experiences with their computers --this available back issues. Send $7.50 to Buss, 325 -B is far more valuable than an article based on the Pennsylvania Ave. SE, Washington, DC 20003.

priced GE portable, and the interference with my first setup was pretty bad. Something about the length of the lead

to the TV set got me to thinking. I remem- T8chnic8I ber making dipole antennas, and somehow 4 feet seemed like a familiar dimension. Channel 3's picture carrier frequency is about 61 MHz, for a wavelength of about Forum 5 meters. The cable from the modulator to the color set is about 4 feet (1.2 meters) long or almost exactly a quarter wave. That makes it a very good antenna for any harmonics (60 thru 65 MHz) of the Apple Resonating Modulators clock, character generator, etc. The cable is looped through a large ferrite toroid, which helps quite a bit, but a simple modification

Allen Watson I l I makes things even better. All you have to do 430 Lakeview Way is add an 18 inch extension cable, thus Redwood City CA 94062 mistuning the channel 3 antenna, and 90 percent of the interference will disappear.

As a recent Apple I I purchaser, I enjoyed We just got around the problem of radio your review of the Apple II (March 1978 frequency interference with our Apple ll

BYTE, page 1 8). I was especially interested by use of the M & R Enterprises UHF to see that you encountered most of the modulator recently acquired. Without even

same problems I did, such as the inter- putting a single toroidal balun core on

ference with the color receiver. I too am the coaxial cable, the same Panasonic using the M & R Enterprises modulator that color television runs without any inter- installs inside the Apple II along with a low ference.... CH

ILLUSTRATING BASIC AN INTRODUCTION TO THE STUDY A Simple Programming Language OF PROGRAMMING LANGUAGES

DONALD ALCOCK D. W. BARRON

"Here's a book . .. to introduce complete beginners to the "One of the most interesting books available in the field of BASIC language in a charming way. Every page is illustrated computer science. Not a mathematical treatise, this text in pen and ink style; even the body of the text is might be retitled: 'Everything you always wanted to know handlettered by the author. ... Alcock's experience in about computer languages (but were afraid to ask).' " - lecturing about computers to students of all ages shows in his Choice lucid writing and dry humor.... Of the many texts on Hardcover $14.9 5 Paper $ 5.9 5 BASIC, this is one of the most engaging." - Computer Dealer Cambridge University Press Hardcover S 1 0.9 5 32 East 57th Street, New York, N.Y. 10022 Spiral -bound Paperback $3.95

Texas Instruments Introduces 5 V 64 K Byte Programmable Memory A New Color Graphics Computer from Chromatics

Texas Instruments has introduced the with improved cycle times, while bit TMS 4164, a single 5 V 64 K byte density is quadrupled. As a result of the dynamic programmable memory, lower power dissipation, the TMS organized as 64 K byte by 1. It comes in 4164 features a 256 cycle refresh with a 16 pin dual -in -line package, and allows a 4 ms maximum refresh period. upward compatibility with the 16 K Due to TMS 4164 refresh com- byte dynamic programmable memory. patibility with the 16 K byte program- The TMS 4164 single 5 V power mable memory, the basic refresh con- Chromatics Inc has introduced the supply design is TTL compatible, offers troller timing does not require major CG series line of full 8 color graphic and lower power dissipation, and is more changes. The only provision required is alphanumeric readout computers. The immune to system noise. Compact for an 8 bit refresh counter and multi- line consists of 13, 15 and 19 inch mod- layout, and an optimized desigh and plexer when upgrading to 64 K byte els featuring noninterlaced screen process combination for 5 V only from a 16 K byte system. Also con- refresh, high resolution shadow tubes, operation result in improved perfor- tributing to higher system operating and 512 by 512 or 512 by 256 individu- mance. efficiency is a 1.3 to 1.6 percent refresh ally addressable and color selective dots. Access times range from 100 to 150 overhead time, compared to 2.4 percent Each model employs a Z -80 processor ns maximum, with minimum cycle times on the 16 K byte programmable with full memory and input and output of 200 to 250 ns. Power dissipation is memory. (10) structure. The 13 inch model 200 mW maximum or 3 /AM maximum The TMS 4164 is priced at $125. starts at $8995. per bit. Comparing the 462 mW power For further information write to Texas A bulletin describing the system may dissipation of the 16 K programmable Instruments Inc, Inquiry Answering be obtained from Chromatics Inc, memory at 375 ns cycle time, total Service, POB 1443, M/S 669, Houston 3923 Oakcliff Industrial Ct, Atlanta maximum power dissipation of the new TX 77001. GA 30340. memory is a reduction of 60 percent, Circle 593 on inquiry card. Circle 594 on inquiry card.

New Keyboard for 64 and 80 Character Display Video Boards

This new MKB -2 keyboard is designed for use with the 64 and 80 character display video boards. Standard features on the M KB-2 include: a numeric key pad, upper and lower case, cursor control keys, 2 key rollover, and automatic repeat on all keys. The M KB -2 is assembled in a heavy duty steel case with parallel interface, strobe or pulse and on board regulation (5 V, 12 V), and comes complete with standard DB25S connector and black double injection molded keys. The price of the M KB -2 is $149. For further information, write to MicroAge, 1425 W 12th PI #101, Tempe AZ 85281. Circle 595 on inquiry card.

Expanded Book Catalog from BITS Software Handbook of Statistical THE Techniques PROGRAMMING 16,4 6800 MICROPROCESSOR BITS Books to erase the impossible asp

This self- instruction workbook is a guide to the fundamentals of assembly This software handbook, entitled language and machine code programming SIMPLE, comprises over 100 conver- of the 6800 microprocessor and its A new expanded BITS catalog is now sational computer programs written in peripheral devices. Considerable coverage available, featuring books on micro - BASIC for teaching statistics and exper- is given to programming of input and computing and other related subjects. imental design to students from all output devices. The asynchronous com- There are new books on business and engineering, science, business and social munications interface adapter and pe- calculators, Pascal, artificial intelligence, science disciplines. Course organization ripheral interface adapter, each with robotics, programming, hardware, games around the modular structure is consid- its various modes of operations, are and much more. ered; and the manual contains a descrip- explored in detail in both noninterrupt BITS has a complete selection of tion of each program, the program input and interrupt modes. Program design and professionally reviewed microcomputer and format requirements, a sample documentation are emphasized along books (over 150 titles), including a problem, a copy of the terminal user with programming hints and aids. number of self- published works. Their dialogue and an explanation of what the Programming the 6800 Microprocessor inventory has been expanded to include results mean in practice and the BASIC by R W Southern is available from a greater number of posters and specialty program itself. Southcroft Publications, POB 11703, items of interest to the computer enthu- The price for this manual is $10.95. Station H, Ottawa CANADA K2H 7T8, siast. Request your free catalog from For further information contact Sterling for $6.75. Submit US funds for US BITS Inc, Dept 3, POB 428, Peter- Swift Publishing Company, POB 188, delivery; Canadian funds for Canadian borough NH 03458. Manchaca TX 78652. delivery. Circle 564 on inquiry card. Circle 565 on inquiry card. Circle 566o n inquiry card.

New Publication Devoted to New Text on Basic Pulse Circuits The basic building blocks of modern TRS-80 User computers, radar, television and pulse Dump Publications has announced communication circuits are presented the release of a software publication for in this programmed text entitled A users of the Radio Shack TRS -80 micro- Programmed Course in Basic Pulse Cir- computer system. Dump is a monthly cuits, by the New York Institute of periodical incorporating news, informa- Technology. tion, and running software ready to load This 293 page programmed learning from a 33 1/3 revolution per minute text is organized in a logical sequence disk record. The Dump disk can be of interrelated steps. Discussions on loaded into the TRS -80 system with the switching devices such as unijunction use of an ordinary phonograph. transistors and silicon controlled rec- Each issue contains a wide variety of tifiers are included. All devices are programs from finance and education to solid state, and some material on inte- games and machine language. Programs grated circuits is presented. Each chapter are provided with complete documenta- begins with a set of objectives and tion and line editing information for concludes with a set of criteria tests to Level I and II BASICs. measure progress. A 1 year subscription costs $20. For The price of this text is $9.95 and it more information, contact Dump Pub- can be obtained from McGraw -Hill Book lications, POB 2454, Jacksonville FL Company, 1221 Av of the Americas, 32203. New York NY 10020. Circle 567 on inquiry card. Circle 568 on inquiry card.

210 December 19780 BYTE Publications Inc The New Hobby World Catalog

Your source for factory prime, professional quality equipment. Computers, add -on boards, IC's, sockets, resistors, supplies, tools, test THE BEST FOR BOTH WORLDS equipment, books, and more. Shop your buy list Factory prime electronic equipment for both the at Hobby World. You'll find what you want, and at discerning hobbyist and the professional a solid savings.

This month's specials.

161( MEMORY ADD -ON FOR APPLE Hobby World Carries TAB Books! Affordable books for OR TRS-80 the hobbyist. Hobby World helps out with a 10% Hobby World price is only $99.00 (specify when discount. (Order by number, and don't forget the 10% ordering) discount)

NEW FROM SSM.THE CB -1 8080 CPU BOARD AT A Computer Circuits and How LIST PRICE HOBBY WORLD SUPER SPECIAL, (See SSM ad for specs) They Work #538 $5.95 It's Loaded. Its Blue. IT'S ONLY $119.95 Beginner's Guide to THE NEW ELENCO 3'/2 DIGIT SOLID Computer Logic #548 $5.95 STATE MULTIMETER Computer Technician's in performance: measures The ultimate resistance to Handbook #554 $9.95 .01 ohms, voltage to 100 micro -volts, current to one micro -amp. Assembled and tested, with 2 -Year Build Your Own Working warranty. Lists at $99.95. Hobby World: $74.95 Robot #841 $5.95 Programming WAHL ISO -TIP CORDLESS SOLDERING IRON Microprocessors #985 $6.95 Includes ni -cad batteries and wall plug transformer. Lists at $19.95, but Hobby World has it for $14.95! Beginner's Guide to Computer Programming #574 $9.95 S100 WIRE WRAP BOARD Over 3600 holes, for super versatility. Provisions for 4 Digital Electronics: regulators. Double- sided, plate -through. All S -100 pins Principles and Practice #585 $5.95 labelled for number and signal. The PT -1. Hobby World Price: Only $30.00 Microprocessor/Micro- programming Handbook #785 $6.95 Hobby World TELEPHONE ORDERS 19355 Business Center Drive "6 Inside Calif: 213 886-9200 Computer Programming Northridge. CA 91324 Outside Calif:800 423.5387 Handbook #752 $9.95

Order by mail. Just write. Or order by phone. Toll free outside SEND ME THE FOLLOWING SPECIALS! California. Item Quantify Price SEND ME A CATALOG!

Name

Address PostagelHandling S1.50

City State California Residents add 6% Sales Tax Satisfaction 100% Guaranteed Charge My MC VISA Signature Expiration

Circle 170 on inquiry card. BYTE December 1878 211 High Speed EXORcisor Memory What's New? MEMORY

16 Bit Microcomputer Module

'.,' >_ lr`,

{i I llrit'i «.,'e ' I

ï ,Itu.lautu!Al" jj\ M¡ Designed specifically for operation cco Cti (Mgli71 -- a U\ . yN i ' with Motorola EXORcisor and ,1 erq MEC 6800 evaluation module is Chrislin t I ' 4n;.. Industries' new C16800, 16 K by 8 bit semiconductor memory system. The new memory allows expansion to 32, 48 and The TM 990/100M series offers up to prototyping system. A user's manual 64 K bytes by interchanging the 4027 4 K words by 16 bits of erasable read detailing the hardware and software of 4 K by 1 bit dynamic memory with the only memory and up to 2 K words by 16 the TM 990 board will be supplied with 16 K equivalent. No further modifica- bits of static programmable memory on each unit. A wide line of accessories and tion is required. The CI6800 memory board. The board also contains two serial peripherals also available. board plugs directly into existing EXOR- input and output (10) ports; one is in- Pricing on the fully assembled and cisor connectors.

tended for remote usage with a terminal tested TM 990/101M -1 including 1 K It allows maximum processor or modem, the other for local usage with word by 16 bit erasable read only mem- throughput with the use of hidden re-

Texas Instruments' 301 Microterminal, ory and 1 K word by 16 bit static pro- fresh control logic on board. Data access an EIA terminal or a Teletype. grammable memory is $625 in single time is 300 ns and cycle time is 750 ns. The TM 990/101 M series offers three quantities. Inquiries should be forwarded On board memory select is available programmable interval timers, up to 17 to Texas Instruments Inc, Inquiry Ful- in 4 K byte increments up to 64 K words interrupts and 16 lines of programmable fillment, POB 1443, M/S 653 (Attn: of memory. A write disable switch on parallel 10. The TM 990 series is sup- TM990), Houston TX 77001. board makes the programmable memory ported by Texas Instruments' AMPL Circle 555 on inquiry card. a read only memory to the outside world. Complete board power consumption S -100 Compatible Single Card Plug -In NMOS Memory is under 5 W. The boàrd size is 5.75 by 9.75 inches (14.61 by 24.77 cm). For more information, contact Chrislin In- dustries Inc, 31312 Via Colinas #102, Westlake Village CA 91361.

Circle 556 on inquiry card.

The system consists of the memory array with support electronics including address and data buffering, timing and control, and voltage regulation. The memory array is divided into four 4 K by 8 bit memory blocks, and each block can be assigned to a 4 K byte address block within a 0 to 64 K byte range. Operating modes are read, write and deposit. The deposit mode is a phase memory cycle consisting of a write followed by a read. For complete information contact This 16 K word by 8 bit program- assembly which is fully burned -in and Electronic Memories and Magnetics mable NMOS memory system is S -100 tested. The Model 1104 uses EMM 4 K Corp, 12621 Chadron Av, Hawthorne and card size compatible. The EMM byte static programmable memories, CA 90250. Model 1104 is a single card plug -in and no refresh circuitry is required. Circle 557 on inquiry card.

212 December 1978 © BYTE Publications Inc PLACE ORDERS TOLL FREE: 800/42800/421 -5809 Continental U.S. SASE 800/262-1710800/262 -1710 inside California Computer Products EPROM BOARD NITSKITS RAM'N'ROM EXPANDOR'S BLACK BOX PRINTER TRS i U (16K any EPROM) $117.00 This 64- character ASCII impact -80 ION MR -8 (1K RAM, uses printer with 80- column capability MEMORY EXPANSION KITS 2708) $99.50 is portable and uses standard 4116's MR -16 (1K RAM, uses 8'A" paper and regular typewriter 2716) $99.50 ribbon. Base, cover and parallel (16Kxl, 250ns) EPM -1 (uses up to 4 K interface are included. Assembled 8 for $85.00 of 1702) $59.95 and complete with manual and JG8/16 (uses 2708 or documentation. TRS -80 KIT 2716) $69.95 includes connectors and only $430.00 instructions $98.00 MICROPROCESSORS (90 day manufacturer's warranty) F8 $16.95 Z80 (2MHz) $20.00 sAnm Z80A (4MHz) $25.00 8080A CDP1802CD 517.95 TRS -80 Interface Cable for Black Box Printer with full documentation 2650 $19.95 with mating connectors: $48.00 Kit $100.00 AM2901 $20.00 (must be used with expansion module, +8v/1 amp power 6502 $11.95 supLlyequ red). Assm. & Tested $149.95 6800 $16.95 -i Bare Board $30.00 6802 $25.00 Power Supply for TRS -80 /Black Box Printer $49.00 8008 -1 $12.95 8035 $20.00 8035 -8 $21.00 »STATIC RAM , SADE Z80 8080A $10.00 JDME7 PARALLEL /SERIAL with provisions for ONBOARD 8085 $23.00 SPECIALS and POWER ON JUMP TMS9900TL $49.95 INTERFACE 2708 8080A SUPPORT DEVICES 2114's,low power (1024x4) S -100 compatible, 2 serial 2 MHz I/O ports, 1 parallel I /O. 8212 $2.90 1 -15 16 -99 100 + Kit $135.00 8214 $4.65 Kit JG -P /S $124.95 Assm. & Tested $185.00 8216 450ns 8.00 6.95 5.50 $2.75 Ass. & Tested 4 MHz 8224 (2MHz) 4.30 250ns 9.00 8.00 6.50 JG -P/SA $179.95 8224 -4 (4MHz) $9.95 Kit $149.95 8226 $2.75 TMS4044/MM5257, low power Bare Board 8228 $6.40 with manual $30.00 Assm. & Tested $199.95 8238 $6.40 450ns 8.00 7.50 6.50 Bare Board 535.00 8243 $8.00 8251 $7.50 250ns 9.95 8.75 8.00 MD -690a CPU BOARD 8253 $20.00 FLOPPY DISK INTERFACE 8255 $8.50 4200A (4Kx1, 200ns) JADE FLOPPY DISK (Tarbell S -100 Compatible 6800 MPU 8257 $20.00 board) 1K x 8 RAM, PROM 8259 $20.00 9.95 8.50 8.00 expandable to 10 K. 8275 $75.00 Kit $175.00 8279 $18.50 Assm. & Tested $250.00 $199.95 USRT S.D. Computer Products S2350 $10.95 "Versa Floppy" ja. shugart DISK DRIVES UARTS Kit $159.95 AY5.1013A $5.25- Assm. & Tested $189.95 A Y 5 -1014 A $8.25 TR 16026 $5.25 Gook! TMS6011 $5.95 STATIC RAM BOARDS \ IM6402 $9.00 IM6403 $9.00 DYNAMIC RAM BOARDS JADE 8K Kits: 450ns $125.95 BAUD RATE GENERATORS EXPANDABLE TO 64K , 250ns $149.75 aart,_,. - _, MC14411 $10.00 14411 Crystal $4.95 6800 PRODUUT 32K VERSION KITS Assembled & Tested: 6810P 450ns $139.75 6820P 6.60 Uses 4115 (8Kx1, 250ns) 250ns $169.75 6821P 6.60 be 6828P $11.25 Dynamic RAM's, can Bare Board: $25.00 6834P 16.95 expanded in 8K increments up 6850P $8.65 16K - Uses 2114's (low power) 6852P $11.00 to 32K. Assembled & Tested: 6860P $9.25 8K $199.00 6862P $12.00 RAM 16 (250ns) $375.00 SA 400 $295.00 6871P $28.75 16K $255.00 RAM 16B(450ns) $325.00 Single- density 51 /a ", 35 track 6875P $8.75 24K $310.00 drive. 6880P $2.50 MEM -2 Kit: 68810P $6.00 32K $369.00 250ns $285.00 SA801 R $495.00 KIM SUPPORT DEVICES Single-sided 8" floppy disc 64K VERSION KITS 16K with memory management 6102 $8.00 drive. 6502 $11.95 Assembled & Tested: Uses 4116 (16Kx1, 250ns) OM 2700 -S $750.00 6520 $10.00 RAM 65 (250ns) $390.00 6522 $9.25 Dynamic RAM's, can be Includes SA801 R disk drive, 6530 $15.95 expanded in 16K increments RAM65B (450ns) $350.00 10" x 10" x 16" cabinet, 6530 -002 $15.95 power supply, data cable, fan, 6530 -003 $15.95 up to 64K. 32K Static AC line filter. 6530 -004 $15.95 Assembled & Tested: 6530 -005 $15.95 16K $292.00 6532 $17.95 32K $432.00 250ns $795.00 S -100 MOTHER BOARDS CHARACTER GENERATORS 48K $578.00 450ns $725.00 2513 Upper ( -12+5) $6.75 64K $721.00 250ns Kit $575.00 JADE 6 -SLOT 2513 Lower ( -12T5) $6.75 Kit $41.95 2513 Upper (5 v-olt) $9.75 2513 Lower (5 volt) $10.95 ALL PRICES SUBJECT TO CHANGE Assembled & Tested $56.95 MCM6571 up scan $10.95 Bare Board $24.95 MCM6571 A down scn $10.95 PROMS WITHOUT NOTICE 9 -SLOT "LITTLE MOTHER" 1.702A $8.00 2708 $9.95 2716'(5 +12) TI $25.00 Kit $85.00 2716 (5v) INTEL $60.00 SA Dn Assembled & Tested $99.00 2758 (5v) $23.40 Bare Board DYNAMIC RAMS Computer Products $35.00 416D/4116 (250ns) $12.50 13 -SLOT "QUIET MOTHER" 2104/4096 $4.00 4901 W. ROSECRANS AVENUE 21076 -4 $3.95 THE PIGGY IS Kit $95.00 TMS4027/4096 1300ns) $4.00 Department "B" COMING! MM5270 $4.50 HAWTHORNE, CALIF. 90250 Assm. & Tested $110.00 MM5280 $3.60 Bare Board $40.00 STATIC RAMS Q-- /I\ 1 -15 16 -100 }- SLOT "STREAKER" 21 L02 1450ns) $1.50 $1.20 uw d 22- 21 L02 (250ns) $1.75 $1.50 w!nESs Assm. & Tested $149.00 2101 -1 $2.95 $2.60 140 2111-1 $3.25 $3.00 21121 $2.95 $2.65 FLOPPY DISK Cash, checks, money orders, and credit cards accepted. JADD CONTROLLERS Add freight charge of $2.50 for orders under 10 lbs and VIDEO INTERFACE 1771601 $39.95 S -100 Compatible Serial 1781 $69.95 $1.00 service charge for orders under $10.00. Add 6% KEYBOARD CHIPS Interface with Sockets Included. sales tax on all parts delivered in California. Discounts Kit $117.95 AY5-2376 S13.75 available at OEM quantities. Assm. & Tested $159.95 AY5.3600 S13.75 Board with AMM5740 S 18.00 Bare MM5743 $1800 WRITE FOR OUR FREE CATALOG manual $35.00

Circle 195 on inquiry card. BYTE December 1978 213 Microprocessor Analog Interface Module What's New? PERIPHERALS

24 Channel Digital Input System for Motorola Microcomputers

lfi .aai [111ái1N1fii1 The Wince Analog Interface Module enables laboratory and control engineers to interface thermocouples and other transducers to a microprocessor and interface the microprocessor to motors, servos, etc. Options include a 16 channel multiplexer, an 8, 10 or 12 bit analog to digital converter and one or two 8 bit digital to analog converters. The base price is $99. Write to Wintek Corp,

c..r.r,il;..- 1;1 i..r. :.vi 902 N 9th St, Lafayette IN 47904 for i . . I . . ; r further information. Circle 553 on inquiry card.

Computer Video to UHF RF Interface Modulator

This single board microperipheral ac- the board is read, logic 0 represents an cepts 24 digit inputs. MP710, with an open contact (low voltage); logic 1, a on board power supply, operates with closed contact (high voltage). Each read dry relay contacts and MP710 -NS with command inputs the status of eight voltage input (wet relay contacts). Each channels. Address bits AO and Al select group of eight inputs is isolated from the set of inputs to be read. The remain- other groups and from the computer bus der of the address lines are used to select up to 600 VDC. In MP710 -NS, isolation the board itself. The address block occu- between inputs is 300 VDC. pied by each board is selectable and can MP710s are electrically and mechani- be located anywhere in memory. Micro is cally compatible with Micromodule and The price of the MP710 is $355 in The -Verter designed to inter- EXORciser microcomputers and operate quantities of one to nine. For further face microcomputers to color or mono- from their +5 VDC supplies. They are information contact Burr -Brown, Inter- chrome television receivers as an alternative the video The Micro - programmed as memory locations and national Airport Industrial Park, Tuc- to monitor. with each input using one memory bit, son AZ 85734.: Verter operates in the UHF channels above channel 14, beyond the normal any read command may be used. When Circle 551 on inquiry card. range of switching harmonics, and is designed to interface directly with the Apple II as well as with most other Process Control Output Module microcomputers. It comes complete with The PCO -1A process control output video cable and radio frequency (RF) module provides two complete 4 to 20 output stub coupler and requires no di- mA or 10 to 50 mA process control cir- rect connection to antenna terminals cuits on one Wyle microcomputer sys- except in special cases. The radio fre- tem output module. The 4 to 20 or 10 quency signal is coupled directly into to 50 ranges are independently select- the UHF tuner input via a 1 cm stub able for each circuit, and both outputs coupler on the back of the modulator. are short circuit protected. The PCO -1 A The approximate size of the unit is 2 is priced at $345 per module (2 output by 3.5 by 4.5 inches (5.5 by 8.5 by 11.5 circuits). Contact Wyle Laboratories/ cm) and it is priced at $35. For more in- Computer Products, 3200 Magruder formation contact ATV Research, 13th Blvd, Hampton VA 23666. and Broadway, Dakota City NE 68731. Circle 552 on inquiry card. Circle 554 on inquiry card.

214 December 1978 ()BYTE Publications Inc Introducing the simple TRS -80 Up -grade

Fast, easy, guaranteed expansion to 16K at less than half the price of Radio Shack. yo reed sstem9cade ás,8010You a 1ßK Ithaca Audio makes SverYi it simple No falsestarts and finding you need some little item or special tool. Our'Kit contains all the parts: 8 prime dynamic ft . i ' ;6KPPMN \nsv"`tons RAMs and a complete set of preprogrammed gata.E toWoleWdltel anC hou5ehod s jumpers. No matter which model you have 0 teyteo mts . tamin9 1 a (even i f you later purchase Level I I software), teQ 1ted'1s r,e Nev+ P^o9 n you're covered. !03, \th' P Complete Instructions Our easy -to- follow directions cut installation time to just minutes. You can do it yourself -with no soldering! All you need is a household screwdriver. Available now, only $140 100% Guarantee Order from your favorite retailer. If by Like our kit, simple: if a part ever fails, we chance he hasn't stocked them yet we'll ship replace it, FREE. him your Kit right away. For technical assistance call or write to: ITHACA AUDIO Phone: 607 /273 -3271 P.O. Box 91 Ithaca, New York 14850 Available off- the -shelf at these fine computer dealers.

AL: Huntsville: Computerland, 3020 University Drive. N.W., (205) 539-1200. CA: Berkeley: Byte Shop, 1514 University Ave.. (415)845-6366. Marina DelRsy : Base 2.13480 Beach Ave.. (213) 822 -4499. Mt. View: Digital Deli, 80 W. El Camino. (415) 961 -2670. DE: Newark: Computerland of Delaware, Astro Shopping Center. Kirkwood Highway. (303) 738 -9656 FL: Tempe: Microcomputer Systems. 144 South Dele Mabry, (813) 879 -4301. IL: Niles: Computerland, 9511 North Milwaukee Ave.. (312) 967 -1714. Oak Lawn: Computerland, 10935 South Cicero Ave., (312) 422 -8080. KS: Overland Perk: Personal Computer Center, 3819 West 95th St., ( 913) 649 -5942. Wichita: Computer Systems Design, 906 North Main St.. (318) 265 -1120. KY: Louisville: Computerland, 813 -B Lyndon Lene, (502) 425 -8308. MA: Cambridge: Computer Shop. 288 Norf olk St.. (617) 661 -2670. MD: Rockville: Computerland, 16065 Frederick Rd., (301) 948 -7676. MI: Royal Oak: Computer Mart,1800 W. 14 Mlle Rd., (313) 576 -0900. NJ: Budd Lake: Computer Lab of NewJersey, 141 Route46, (201) 691 -1984 Clark: S -100, 7 White Place. (201) 382 -1318. Iselin: Computer Mart of New Jersey. 501 Route 27, (201) 283 -0600. Succasunna: Computer Hut,15 Route 10, (201) 584 -4977. NY: Buffalo: Computerland. 1612 Niagara Fells Blvd., (716) 836-6511. Dewitt: Computer Enterprises, 3470 Erie Blvd. E., (315) 637 -6208. Ithaca: Computerland of Ithaca. 225 Elmira Road. (607) 277- 4888. New York City: Computer Mart of NY, 118 Madison Ave.. (212) 686-7923. Johnson City Micro World. NYPENN Trade Center. RM 217. 435 Mein Street. (607) 798 -9800 OH: Cincinnati: Digital Design, 7694 Comargo Rd., (513) 561 -6733. Dayton: Computer Solutions, 1932 Brown St., (513) 223 -2348. OK: Oklahoma City: Mlcronlcs, 2834 N.W. 39th St.. (405) 942 -8152. TX:Austin: Computerland, Shoal Creek Plaza, 3300Anderson Lene, (512) 452 -5701. Houston: Houston Computer Mart. 8029 Gulf Freeway. (713) 649 -4188. UT: Orem: Johnson Computer Electronics, 699 N. 1060 W.. (801) 224 -5361. VA: Alexandria: Computers Plus. 678 So. Pickett St., (703) 751 -5656. Arlington: Arlington Electronics Wholesalers, 3636 Lee Highway. (703) 524 -2412. VT: Essex Junction: Computer Mart of Vermont. 159 Pearl St., (802) 879.1683. CANADA: Ontario: Miss ssaugua: Arista Microsystems. 1455 Gregwood Rd.. (416) 274- 6033. Toronto: Computer Mart Ltd. 1543 BayviewAve.. (416) 484 -9708. WEST GERMANY: Munich: A.B C. Computer Shop, Schelling- strasse 33. 8000 Munchen 40. Microcomputer Shop. Toelzerstr. 8. D -815 Holzkirchen. ISRAEL: Haifa: Microcomputer Eng. Ltd , Haifa 31 -070.

BYTE December 1978 215 Hard Copy Graphics Terminal What's New? PERIPHERALS

Z -80 Arithmetic Processing Unit Fully compatible with the Zilog Z -80 MCB, this high speed arithmetic

processing unit board ( HAPUB) provides the hardware necessary to accomplish arithmetic, trigonometric, inverse trigonometric, logarithmic, exponential and square root functions. HAPUB simplifies software and allows the Z -80 to perform other operations while This plotter system, called accomplishing these functions. Also Panographic -84, has a resolution of 100 featured are fixed point integer single steps per inch in the X and Y directions and double precision (16 and 32 bit), and a cumulative error of less than .020 and floating point single precision inches (.05 cm) in 10 inches (25.4 cm) (32 bit) operation with bidirectional of travel. The drives are stepping motor conversion capability. The board is operated for zero drift and no adjust- compatible with the Zilog Z -80 card ments. Interfacing with a computer is cage and 8 bit bidirectional data bus and via eight wires from the plotter to a costs $749. Contact Signal Laboratories parallel port. When driving the plotter Inc, 202 N State College Blvd, Orange from BASIC language programs, com- CA 92668. plete handshaking is not required since Circle 525 on inquiry card. the plotter response is considerably faster than the speed at which BASIC can drive it. If the user wishes to drive Triple Output DC Power Supply the plotter from a machine language routine, full handshake capability is available. The polarity of handshake signals is switch selectable. Options available at present consist of a computer operated pen lifter and a vacuum formed plotter cover. Soft- ware provided with the system is written in BASIC and listings of these short routines are provided. The price for the plotter kit without pen lifter and cover is $995. The pen lifter kit sells for $85, as does the molded plotter cover. A factory assembled plotter with pen lifter and cover sells for $1400. For more information, write to Pan Dynamics Inc, 2950 Nebraska Av, Santa Monica CA 90404. Circle 526 on inquiry card.

Where Do New Products Items Come From?

The information printed in the new products pages of BYTE is obtained from "new product" or "press release" copy sent by the promoters of new products. We ±12 Power -One has announced an addi- isolation between the 5 V, V and openly solicit releases and photos tion to their Hi -Vol series triple output ±15 V outputs allows the user to arrange from manufacturers and suppliers DC power supply line. The new model, polarities to suit specific applications. to this marketplace. The infor- is Standard features designated HCAA -60W, built in the include 115/230 mation is printed m ore or less as a industry standard package size for a VAC ±10% AC input capabilities, first in first out queue, subject to 60 W triple output open frame power +0.05% line and load regulation, and occasional priority modifications. supply. This model outputs 5 V at 6 A full protection against short circuit While we would not knowingly with adequate overvoltage protection, and overload. Maximum output ripple print untrue or inaccurate data, or +12 to 15 V at 1.0 A, and -12 to 15 V is 3 mV peak to peak. data from unreliable companies, at 1.0 A. The -12 to 15 V output may Each unit is tested and burned in our capacity to evaluate the probe changed to -5 V at 0.4 A by jumper - and carries a 2 year warranty. The size ducts and companies appearing ing two printed circuit board terminals. is 9.0 by 4.87 by 3.2 inches (22.86 by in the "What's New ?" feature is Targeted use in systems requiring 12.37 by 8.13 cm) and weighs 7.5 for it necessarily limited. We therefore DC voltages, the HCAA -60W is multiple pounds (3.36 kg). The price $84.95 cannot be responsible for product will power combinations of most semi- from Power -One Inc, Power -One Dr, quality or company performance. conductor devices including TTL, PMOS, Camarillo CA 93010. NMOS, CMOS and linear devices. Total Circle 527 on inquiry card

216 December 1978 0: BYTE Publications Inc

A 1 FORNiA DÎqiTAL Post Office Box 3097 B Torrance, California 90503

This is a one time purchase of CLAREPENDAR NEW Surplus keyboards, re- General Instrument Carp. cently aquired from the Tele- communications Division of the Even it we have to give them KEYBOARD Singer Corporation. Quiet away, we're going to ship more 43's In 1979 than the aggregate ASCII ENCODED The keyboard features 128 BUSS of all our competitors. The Iron I ASCII characters in a 63 key Oulel Buss California Industrial quality engineered. No short cuts hard been taken format, MOS encoder circuitry 52995 to produce this mother board. Active termination Model43AAA (TTL) "N" key rollover, lighted shift circuitry prevents d crosstalk. Minutes-M 1 s . tinedd Ira FRI lRRBOtO! lock, control, escape and re- 8803 -18 Goxyp EACH 3 10 25 ' 11.11101111110101111 - pete functions. I11r -r"Ir 1 ItII I I 18 slot I rl i t !L $925. 875. 850. 825. and s QsNlleseE - Sloped pannel positive feel In- switches, makes this profes- IMSAI RS -232 Interface "K "Addt759D sh°luDDIni sional quality keyboard an excellent buy at only ,$84.95. KÉ $64.95 Limited Quantities. HEXADECIMAL KEYBOARD Maxi- Switch heaadenmal keyboards are designed Or s RS rs SACS Ntet isdmputor systems mat require 4011 output 3 4 $3495 6 7 9 0 seat[ IS \ in clard hex code. .29- Box of 10 FTB N 95 REPEAT et- Each assently consist, of le her melt. Q W E ® e® rtm rua catty sealed read swllenes and TTL "ono SON OC oT AC x BEL vT FF is Ihordebouncecircunry. NULL A S D F G H J K ) Lrrt Reliable low friction accial ream sue CAM EC SYI STM plungers erec rodiledl°ribs. smooth CTRL SHIFT z x V B N SHIFT CTRL operation andlong lit. oil his premium keyboard. DISKETTES SPACE Requires smote 5 roll supply APPLE /TRS -80 Vyerbatim. Mini - Soft sector Edge CONNECTORS Connectors $24.88 FROM ATARI your choice COLOR TELEVISION SPECiAL DB25P I male plug &hood r. R.F. MODULATOR ar GOLD '1385 The Alan Re Modulator I Ompul« data to ba DB25S female 5ll PIN j)` a,ssd diteopunan your APPLE 11 100 UNIVAC television IMSAI /ALTAIR this unit converts $395 sal Iron, Ins AMCI, and 16K MEMOR tinsel Solder.125 s .250 54.95 3ís10.00 KEYBOARD Qty fe. male hd. Imul wiw.12Scenters 54.95 3.'513.00 COLOR GRAPHICS. SOUND 10 3.45 2.45 Altair soldertail. 140 row $5.95 3/$15.00 ope;sleslom 415 u0plv Ccn. 25 3.15 2.25 1.05 SPECIALS Mit.5ug. 100 2.85 1.90 .95 22/44 Kim eyelet.156" $1.95 3/35.00 connector and Retail .. 500 2.25 1.60 .85 25/50 solder tab .156" $1.09 3. $2.00 u v. R $1024 36/73 wide post w,w.156 51.95 $5.00 naxcavned instructions nemahc 11195 IN 1.97 1.37 .73 3' ',stymied PLUS SHIPPING 5.100 PROTOTYPE BOARD Certified Digital APPLE RS -232 lExtender Board ennuya 51998 SOHAV ,nth , m $59.95 caaress Scotch CASSETTES Serial Interface aeeoabg ana ARANO Interfaces Darkroom bnlg for SIO0 systems. Wonrt dropa BIT! Roo ln' or02 urcorrr.nee 16 Apple II to InuI1M x3495 pin IC s. 5 b us burn a ats DISKETTES *5so Teletype or Facilitates design and trou- odng hps. 10P coaress CALIFORNIA Timer Kit select switch. a 5 roll reg,. other seri- As featured In the August '78 issue bleshooting of all S -100 mi- leIm onamore Sinch Soft(IBM1 INDUSTRIAL wW ldPWire wrap bread. is an al printer. of POPULAR ELECTRONICS. crosystems. Includes logic 8inch32sector board sm..ar lathe GP100 Authorized T'me I second to 10 hours probe along with high -low Alulwsw rowroap1ol a'I Vas Mini Soft sec. Dealer of ELECTRONIC and pulse LED display. d sax y sins d Information ono Mini 10 Scotch Brand seams n conbhoaoa. sector $3495 upon request. Also available, the Mullin regubor on gaud ro'oge 16 Data Products SYSTEMS pie 000 Mini sector C13-1 controller board Î$88. ions T umbwheel MEMORY TERMINAL switch CRT Ten position DYNAMIC 1 -7 8 -32 32+ Sanders Associates BCD 4115 8Exl 11.95 11.50 5139 ea. 4110 16Kx1 1 3. 95 13. 00 1 2.25 These used vldto display terminals were (fpplc II & TRS 80) in working condition when we purchased 10 50 * your choice 4164 IlFal * * a 1116 .89 them front the reservation division of I 100 Ik 10 50 major U.S. airline. As you may be aware, publishers CAPACITORS $98 $.88.81.73.66 The terminals are R5 -232 and should gas require advertisers to submit their SPOT Miniature Toggles ad copy 60 to 90 days prior to "press" -. ily interface to most microcomputers. CON ON NONEON date. That much lead time in a volatile market place, ro facilitate a quick liquidation of these ELECTROLY TICS 7101 , 7107Í6t ON-OFFImnt.ON) such as memory circuits, makes it extremely difficult units, we are offering them as ea. 10 50 -is, 7108 CR Obi to project future cost and availability. ON-Imoment. non -returnable for only $149. 80,000/10v. 395 349 295 Rocker 1BT DPDT To obtain the best pricing on memory we have made Please Include $35.00 for shipping, 4500/50v.S149 135 119 Rotary -3P -4 .Pox. volume commitments to our suppliers, which in turn Rotary 3F-6-Pas. the balance will be refunded. 1000/15v S.55 49 45 affords us the opportunity to sell these circuits at the mal PushB ON.O.) S.39ea. 4'51 most competitive prices. Please contact us if you SPECIAL SPECIAL SPECIAL DIP Switch if you have a demand for volume state of the art mem- .1 S.12 .09 .07 PowerAdapter Only 10,000 disc Available 10 25 100 l8 ory products. .01 disc .06 .05 .04 si 49 6vdc,140mA $139 'a 5129115 .97 83 STATIC 1 -31 32 -99 100 -5C -999 ll:C 7vdc, specify 21 L02 450nS. 1.49 1.19 1.05 .95 .89 1.4 A. 5.50 NE555H Leads Ian out to tit 018005. 21L02 250nS. 1. 69 L 49 1.45 e 9 vdc$00mA. 1.19 - 50 $69 Mini DIP social. 2114 11tix4 450 6.95 G. 50 6.25 6.00 5.75 Conductor Ft. 10 vAc,300mA. 1 95 l,v^ * 2114 1 Kc-1 300 8.95 8.50 8.00 WIR 3 for $.98 4044 411x1 450 8.95 8.50 8. oo o IBBON TWISTED 25 toe A7.01).100 í1950 40-14 41tix1 250 9.95 9.50 1.00 : PAIR 4045 1Kx4 450 8.95 8. 50 8.00 * DISCOUNT 1045 1KxI 250 9.95 9. 50 9.00 * Transistors 5257 low pow. 7. 95 7. 50 7.05 6.75 6.45 ea. 10 50 100 Wire Wrop &enter CIRCUITS 2N22224 .20 .18 .16 .15 SPECIAL 2N3055 .69 .65.59.55 Heavy IC SOCKETS M13055 .79 .75 .69.65 ZAOA 4 AllI, 24.95 AY5 -1013A LIART 4.95 01.1 I`Ill duty grounded .4. ..p low pro ile ea. 25 50 ea. 25 50 8080A CI'U 9.95 Floppy Disc Controllers 2N3772 159 149 1.39109 12v.ct. 175mA. power cord and mating pin 8085 22.50 WD 1771 single D. 39. 95 2N3904 .15 .11 .09.07 TRANSFORMER chassis connectors. 8 17, 16 15 wvótr.i 8086 Intel 16 bits WD 1781 Double D 65. 00 v.d .07 16 bits 2N3906 .15 .11 .09 14 37, 36 35 18 17 16 rslsso0o 49.95 WD1791 D/D3740 1."-;'5 TRIMMER Page Wire Wrap Kits Diodes POTENTIOMETERS 16 38 37 36 19 18 17 to 25 100 precut & stripped 52995 -r 1 -15 16 -63 64+ 24 99 93 85 36 35 34 E PROMS 1N4002 000,..08 06.05 2K 5K 10K 506 BW 630 1702A 21i 4.95 4.50 4.00 KIT No.1 66 ?5 AO 169 155 139 63 60 58 1N4005 608e..10.08.07 X14 900 Assorted Lengths 2708 8i`. 9.95 9.50 9.00 r 5 for 5.98 HOBST WRAP-30 1114148 signal .07.05.04 r rapactrip Joel 2710 10K 19.95 * * KITNo.2 51995 soll. K YNAR WRAP 'M 2532 32K * * * red 50 100 rs 2800 Assorted Lengths umbo ea. 10 25 100 20 :98 500 1,000 11,000 J 250' Bulk Wire 5545 LED's s15,1ä1109 16' 14' 12, 59. 515. 5105. 1213) 679.9001 Ae mercMnmea sold es. Califon. Indutld 1la prrmlum oraer. orwm ..e ahrsnee the um. do remtlmo PLEASE INCLUDE $1.00 SHIPPING ON ORDERS LIMPER L Is 00 Callfor renle add 6, gain .s Money hack guarantee. Sorry. ea COD's F*eel an orders add 10'. Credit cards accepted. 520 minimum Circle 39 on inquiry card. BYTE December 1978 217 Floppy Disk Systems Software Transparent to RT -11 What's New? MASS STORAGE

Mass Storage Unit Expands System 88 Filing Capabilities

The new Remex -11 floppy disk systems are integrated hardware and software units that connect directly to the PDP -11 Unibus or LSI -11 Q bus. The systems are available with a utility function that permits data interchange between IBM 3740 diskettes and any RT -11 supported device. The new plug compatible versions of the Remex -11, the Remex 11/11 and 11/12, are completely software transparent to the RT -11 software on the LSI -11 computers while offering added features. The Remex -11 provides read only memory bootstrapping as a standard feature as well as individual write protect PolyMorphic Systems has increased nesses and professional offices. switches to each drive, busy and error the storage capacities of its System 88 Present owners of any System 88 status indicators, and an automatic re- microcomputers through the microcomputer can add the 88 /MS introduc- initialize function. tion of a new option, the 88 /MS, which mass storage unit with no changes in For increased performance while consists of two drives for 8 inch floppy their equipment's operating system. still maintaining media compatibility disks. One disk can hold 1.2 M bytes, or Ready to use packages are available for with PDP -11 and LSI -11 systems, the more than 500 pages of text. A System doing tasks such as accounts receivable. Remex 11/21 and 11/22 are available. 88 microcomputer with one or two For more information on the 88 /MS, These systems will accept up to four 88 /MS units can handle all the files and contact PolyMorphic Systems, 460 Ward diskette drives. Data can be transferred processing needs of most small busi- Dr, Santa Barbara CA 93111. in 16 bit words, and up to 65 K words can be transferred in a single input/ Short Length Cassettes Designed for Personal Computers output (10) operation. For additions, the data buffer in the RT -11 controller can be increased to two full sectors. The Remex 11/31 and 11/32 employ 16 sector and track soft sectoring format. A contiguous file allocation structure increases throughput by as much as 50 percent. Both media compatible and expanded capacity systems connect to the PDP -11 by a bus extension cable; therefore no 10 slot is required. Remex -11 prices begin at $3195 complete. For further information contact Marketing Manager, Remex Division, Ex-Cell-0 Corp, 1733 E Alton St, Irvine CA 92713. Circle 597 on inquiry card.

New Floppy Disks from Omni Products Company

New floppy disks are available from Omni Products Co, POB 223, Marlton NJ 08053. The disks include a full IBM compatible, soft sectored version, as well as Shugart compatible, hard sectored and Memorex compatible, hard sectored versions. They are designed to meet or ex- Microsettes are short length, high of tape in the C -10 Microsette provides ceed IBM and ANSI standards, and a quality cassettes designed for micro- slightly more than five minutes of written guarantee is furnished. Prices are computers. They feature a premium recording per side. For additional in- $4.95 in quantities of one through nine quality Philips cassette and high energy formation about the C -10 Microsette and $4 for orders of more than 50. audio tape. Each cassette comes in a write to Microsette Co, 777 Palomar Include $1.50 for shipping per order. NJ hard, 2 piece Norelco style box with Av, Sunnyvale CA 94068. residents should include 5% sales tax. two extra labels. The 50 foot length Circle 596 on inquiry card. Circle 598 on inquiry card.

218 December 1978 ©BYTE Publications Inc O. : .;.. -, " 16K E -PROM CARDN : . IMAGINE HAVING 16K OF SOFTWARE ON LINE AT ALL TIME! . 5 -100 KIT FEATURES: Ilmsai/Altairi Buss Compatible! . .. 1. Double sided PC board with solder V e mask and silk screen and gold plated - -- contact fingers. ¢ eels .1 i.. till l. .I::..!.. Rli'. 55...... 2. Selectable wait states. - .95 kit 3. All address lines & data lines buf- a 5 9 tend: ... . 4. All sockets included. regulators. :.ii 5. On card 1 ( SPACIAL OFFER: .. KIT INCLUDES ALL PARTS AND SOCKETS (except 2708's). Add $25. for I Our 2708's (450NS) are $8.95 .. assembled and tested. - when purchased with above kit. . :.ii .. NEW PRODUCTS FOR 1979 . New Products are Scheduled for delivery during January 1979. Some may be available sooner. Call. Z -80 CPU KIT 16K STATIC RAM KIT DUAL DENSITY FLOPPY DISC CONTROLLER $129 - ... $295 For S -100 Buss. Reliability and For S -100 Features Buss. Jump Quality assured. Uses WD1791 .... on Reset capability. We feel this For SS -50 (S.W. TECH. 6800) Controller Chip. For 51/4 or 8 inch i ..... Fully static uses 2114 . board has the most correct Buss. drives. Full IBM and S -100 PSYNC signal for trouble free RAM's. 450 N.S. At last, aquality compatible. Perfect for use with operation. Complete kit. More RAM board for this popular Buss CP /M. Special P.L.L. design for .... maximum reliability. Assembled & data on request. (for 4MHZ at an affordable pprice. Complete q Tested - $219 Additional Data .. ADD $10) kit. Additional Data on request. on Request. CPM Is a Trademark of Digital Research of California. .... COMPUTER PARTS ALARM CLOCK CHIP FULL WAVE BRIDGE .... N.S. MM5375AA. Six Digits. NOT ASSOCIATED WITH DIGITAL Z -80 - $19.95 8080A - $6.95 4 200 PIV. RESEARCH OF CALIFORNIA, THE With Data. New! AMP. 2.25 SUPPLIERS OF CPM SOFTWARE. . Z -80A - 24.95 8212 - $2.49 each 69C 10 FOR $5.75 ....S IS.... NS! 2708 EPROMS MOTOROLA 7805R VOLTAGE REGULATOR 450 Now full speed) Prime new units from a major U.S. Mfg. 450 N.S. Same as 7R except 750 output. Access time. 1K x 8. Equiv. to 4 -1702 A's in one package. Same as 5VDC output. .... 44c each or 10 for $3.95 $15.75 ea. $995 00- é .. PRICE CUT 529500 ASSEMBLED ESTED COMPLETE KIT 16 K STATIC RAM KIT ADD $30 . .. OUR LATEST COMPUTER KIT! FULLY S -100 COMPATIBLE! FULLY STATIC, AT DYNAMIC PRICES! ' 1 .. WHY THE 2114 RAM CHIP? - - " -" -. - . . . KIT FEATURES: We feel the 2114 will be the next industry I...... 1. as four 4K RAM chip (like the 2102 was). 1,1 separate standard -- g 11111111111, 1111, Blocks.ressable This means price. availability, and , I -- ' ' - l' 2. ON BOARD BANK SELECT circuitry. .... quality will all be good! Next. the 2114 is '' - Í. " 1 i t ) -' (Cromemco Standard) Allows up to FULLY STATIC! We feel this is the ONLY - -_ -011 1 1i1i,1 ,",,',11'111,11. . . 512K on Ilne way to go on the S -100 Buss! We've all , j t li 'I..) . 3. Uses 2114 (450NS) 4K Static Rams. . heard the HORROR stories about some Sir 1' 4. ON BOARD SELECTABLE WAIT ... Dynamic Ram Boards having trouble I 1 { STATES. with DMA and FLOPPY DISC DRIVES. + I ,_ '1 PC with problems? T 11E \ 1 5. Double sided Board, solder Who needs these kinds of mask silk screened layout. Gold - ' And finally. even among other 4K Static j plated contact Lingers. RAM's the 2114 stands out! Not all 4K h1 b. All address and data lines full rrPTTT I I_ ' y '! static Rams are created equal! Some of rli buffered. the other 4K's have enable i `1 .w clocked chip t' 7. Kit includes ALL parts and sockets. lines various timing windows just as and 8. PHANTOM is jumpered to PIN 67. roe.. critical as Dynamic RAM's. Some of our PC BOARD WITH DOCUMENTATION - $33.00 BLANK 9. LOW POWER: under 2 amps TYPICAL 16K use these ..... competitors boards SUPPORT IC'S + CAPS - $19.95 from the 6 Volt Buss. is . sise ctrick devices. But not us! The 2114 .S y LOW PROFILE SOCKET SET - $12.00 10. Blank PC Board can be populated as the ONLY logical choice for trouble- any multiple of 4K. seis ... free. straightforward design. 2114'S 4K RAM'S - 8 FOR $69.95 ...fire .. (450 NS) 8,995°° .eels .... SUPER SPECIAL: BUY 32 KITS (512 KILOBYTES) (8 -64K BANKS) for 5.... NATIONAL SEMICONDUCTOR MAtOO8A SALE! Newt REAL TIME BRAND NEW 1N4148DIODES.SILICON. Computer Clock Chlp JUMBO CLOCK MODULE Same as 1N914. New, FEATURES N.S. MM5313. Features FOUR JuMBOv INCH LED DISPLAYS factory prime, Full Leads. BOTH 7 segment and siso .... $695 12 HR REAL TIME FORMAT á ' , ,r. I 6 24 HR ALARM SIGNAL OUTPUT 100 FOR $2 BCD outputs. 28 Pin siso i 50 OR 60 H. OPERATION LEO BRIGHTNESS CONTROL - 1000 FOR $17.50 DIP $4.95 with Data ..s / i// / ; / ; Z FOR POWER FAILURE INDICATOR 1.. a; ETA SLEEP a SNOOZE TIMERS :sise. L 00... DIRECT LED DRIVE (LOW RFD 16K DYNAMIC RAM CHIP COMES WITH FULL DATA .sise 4I (AC XFMR 51.961 410NS S... 16K X 1 Bas 16 Pm Package Same asM sick 41164 250 NS access. cycle _ for the art RAM 32K and WK RAM boards ASSEMBLED! NOT A KIT! COMPARE AT UP TO TWICE lime Our best price yet Ihis stale o ..eels .. using this chip are readily available Th se are new. fully guaranteed devices by a .... VERSION! OUR PRICE! major mfg ZULU PERFECT FOR USE VERY LIMITED STOCK? We nave . fiend. numw. of m 2C4 MR RUI iime. WITH ATIMEeASE. MANUFACTURER'S CLOSEOUT! $14.95 each 8 FOR $89.95 . rs'MMA1008D - $9.98 e TERMS: Add 300 postage, we pay balance. Orders under $15 add 756 handling. No C.O.D. We accept Visa, Master - I..... Digital Research Corporation charge, and American Express cards. Tex. Res. add 5% Tax. (OF TEXAS) Foreign Canada) 20% P & H. 90 Day ... `P. O. BOX 401247Y /GARLAND, TEXAS 75040/(214) 271 -2461 Money alltems. .. '': . ...:. . .i- ¡ Circle 100 on inquiry card. NBYTE December 1978 219 Paper on S -100 Bus Standards of INTEREST to DESIGNERS What's New? A reprint from Computer Magazine entitled "Proposed Standard for the S -100 Bus," Preliminary Specification, S Bus Manual Details New Temperature Switch -100 Prototyping Circuit Board IEEE Task 696.1/D2 was presented at Accommodates up to An 8 page manual detailing the prop- the 1978 National Computer Confer- 70 Integrated Circuits erties and applications of Midwest Com- ence. This document is a specification ponents Inc's temperature switch is for both timing and signal disciplines and available from the company. This switch was prepared by two members of the utilizes a reed switch and temperature IEEE Computer Society Microprocessor activated magnets for sensing. For this Standards Committee. It is available by manual, write to Midwest Components sending a self- addressed, stamped en- Inc, POB 787, 1981 Port City Blvd, velope to Robert G Stewart, 1658 Muskegon MI 49443. Belvoir Dr, Los Altos CA 94022. Circle 607 on inquiry card.

Intelligent Keyboard Has Capacitive Keyswitches

This new solid state keyboard uses a serial and parallel input /output (10), second generation microprocessor and and n -key rollover (3 key rollover low profile capacitive keyswitches. The being standard). keyboard uses an 8 bit single integrated The switches have a life expectancy This new prototyping circuit board is circuit processor with on chip read of 100 million operations. The legends bus and shape compatible with Altair only memory, programmable memory are selectable from a wide selection of and IMSAI microcomputer boards. It and erasable read only memory. All key symbols and letters in a host of lan- holds up to 70 14 or 16 pin dual -in -line functions are software controllable. The guages and disciplines. packages (DIP) or any combination microprocessor permits automatic re- For further information about this of DIP sockets with 0.3, 0.4, 0.6 or peats, multiple application programs in keyboard, contact C P Clare & Company, 0.9 inch (0.76, 1.02, 1.52, 2.29 cm) a single intelligent encoder, field pro- 3101 W Pratt Av, Chicago IL 60645. lead spacing. gram changes using new firmware, Circle 609 on inquiry card. The 5.3 by 10 by 0.062 inch (13.46 by 25.4 by 0.16 cm) Model 8804 circuit board from Vector Electronics 8080 Processor Board Offered has 100 (50 each side) card edge contacts on 0.125 inch (0.32 cm) centers to accommodate an S -100 bus organization. Two 100 hole rows of individual 0.1 inch (0.25 cm) spaced pads across the top of the board permit additional input /output (10) via ribbon wire assemblies. Wrap posts may be fabricated by inserting Vector's T46 -5 -9 wrapped wire pins into the holes. For wiring convenience, power and ground buses are in an offset ladder pattern on opposite board sides. One corner of the 8804 may be used for a low profile heat sink with two regulators in the TO -220 packages. The leads of one regulator position are prewired to power input, ground and regulated power. The other regulator position is uncommitted. This S -100 bus 8 bit processor board for all integrated circuits. The 8804 plug board is priced at uses the 8080A processor. 74LS244 bus The 8080 board is $175 assembled $21.95 each in quantities of one to four. drivers are utilized to provide low power and $1 20 in kit form. For more informa- For further information, contact Vector with higher drive capability. A switch tion write to Electronic Control Tech- Electronic Company, 12460 Gladstone selectable jump on reset circuit is pro- nology, 763 Ramsey Av, Hillside NJ Av, Sylmar CA 91342. vided for use in systems without a front 07205. Circle 606 on inquiry card. panel. Low profile sockets are provided Circle 610 on inquiry card.

220 December 1978 © BYTE Publications Inc A COMPUTER INTERFACES & PERIPHERALS V V E For free catalog including parts lists and schematics, send a self -addressed stamped envelope. E

APPLE II SERIAL I/O T.V. TYPEWRITER 8K STATIC INTERFACE * Part no. 106 RAM Q Part no. 2 Stand alone TVT Baud rate is continuously adjustable 32 char /line, 16 from 0 to 30,000 Plugs into any periph- lines, modifications Part no. eral connector Low current drain. RS- for 64 char /line in- 300 232 input and output On board switch cluded Parallel 8K Altair bus memory ASCII (TTL) input selectable 5 to 8 data bits, 1 or 2 stop Uses 2102 Static memory chips Mem- bits. and parity or no parity either odd or Video output 1K ory protect Gold contacts Wait states On on board memory even Jumper selectable address board regulator S -100 bus compatible Vector Output for compu- SOFTWARE Input and Output routine input option TRI state buffered Board only ter controlled cur - from monitor or BASIC to teletype or other serial printer. $22.50; with parts $160.00 Program for using an Apple II for a video or an intelli- ser Auto scroll gent terminal. Also can output in correspondence code Non -destructive curser Curser inputs: up, down, left, to interface with some selectrics. Board only - $15.00: right, home, EOL, EOS Scroll up, down Requires +5 with parts - $42.00. assembled and tested - $62.00. volts at 1.5 amps, and -12 volts at 30 mA All 7400, TTL chips Char. gen. 2513 Upper case only Board only RF MODULATOR* $39.00: with parts $145.00

MODEM * Part no. 107 Converts video to AM modu- Part no. 109 TIDMA* lated RF, Channels 2 or 3. So Type 103 Full or half powerful almost no tuning is re- duplex Works up to 300 quired. On board regulated baud Originate or Ans- 1--f---" 7'lóit : . . power supply makes this ex- wer No coils, only low 3lfi.:ÌL' tremely stable. Rated very cost components TTL highly in Doctor Dobbs' Journal. Recommended input and output -serial 6 F. is by Apple. Power required is 12 volts AC C.T., or Connect 8 ohm speaker r 3 IUI --_- +5 volts DC Board $7.60; with parts $13.50 and crystal mic. directly to board Uses XR FSK demodulator Requires +5 volts Board $7.60; with parts $27.50 : itlntttlmllmliltlltIIIl111IDltlftttlIllIIIÌ' RS 232 /TTY Part no. 112 DC POWER SUPPLY* Tape Interface Direct Memory Access Record INTERFACE and play programs without bootstrap loader (no Part no. 6085 prom) has FSK encoder /decoder for direct con- a regulated +5 Board supplies volts nections to low cost recorder at 1200 baud rate, Part no. 600 at 3 amps., +12, -12, and -5 volts at and direct connections for inputs and outputs to a Converts RS -232 to 20mA 1 amp. Power required is volts AC digital recorder at any baud rate. S -100 bus com- current loop, and 20mA current at 3 amps., and 24 C.T. at 1.5 volts AC patible Board only $35.00; with parts $110.00 loop to RS -232 Two separate amps. Board only $12.50; with circuits Requires +12 and -12. parts excluding transformers $42.50 volts Board only $4.50, with parts $7.00 oneravo te' TAPE INTERFACE * UART & BAUD RATE Part no. 111 GENERATOR* RS 232 /TTL* Play and record Kansas Part no. 101 City Standard tapes Converts serial to parallel INTERFACE Converts a low cost tape and parallel to serial Low recorder to a digital re- cost on board baud rate corder Works up to 1200 generator Baud rates: 110, Part no. 232 baud Digital in and out 150, 300. 600, 1200, and Converts TTL to RS -232, are TTL -serial Output of 2400 Low power drain +5 and converts RS -232 to board connects to mic. in volts and -12 volts required TTL Two separate circuits TTL compatible All characters contain a start bit, 5 to of recorder Earphone of Requires -12 and +12 volts 8 data bits, 1 or 2 stop bits, and either odd or even parity. recorder connects to input on board No coils a 10 pin All connections go to.a 44 pin gold plated edge connec- All connections go to gold plated edge Requires +5 volts, low power drain Board $7.60; tor Board only $12.00; with parts $3500 with connector connéctor Board only $4.50; with parts $7.00 with parts $27.50 add $3.00 with connector add $2.00

ELECTRONIC SYSTEMS Dept. B, P.O. Box 21638, San Jose, CA. USA 95151

Mention part number and description. For parts kits add "A" to part number. In USA, shipping paid for orders accompanied by check, money order, or To Order: Master Charge, BankAmericard, or VISA number, expiration date and signature. Shipping charges added to C.O.D. orders. California residents add 6.5% for tax Outside USA add 10% for air mail postage, no C.O.D: s. Checks and money orders must be payable il US dollars. Parts kits include sockets for all

I Cs, components. and circuit board. Documentation is included with all products. All items are in stock, and will be shipped the day order is received via first class mail. Prices are in US dollars. No open accounts. To eliminate tariff in Canada boxes are marked "Computer Parts." Dealer inquiries invited. 24 Hour Order Line: (408) 226 -4064 * Circuits designed by John Bell

Circle 125 on inquiry card. BYTE December 1978 221 What's New? SILICON Single Channel DMAC from Western Digital Single Chip Z80-SIO for LSI Microcomputer System

A low cost single channel direct memory access controller (DMAC) has been introduced by Western Digital Corp, 3128 Red Hill Av, POB 2180, Newport Beach CA 92663. The DM 1883 is said to be fully compatible with all popular microprocessors built today. It includes the following features: control of all memory handshaking and device control; full 16 bit memory address and block length capability; block or word move; automatic end of block '(EOB) shutoff and interrupt on EOB or error detection; and the option of auto load and bus timeout interrupt. The DM 1883 is powered by a single +5 V supply. A high speed, dual channel, multi - data in data communications networks. Circle 624 on inquiry card. protocol serial data communications Each of the SIO's full duplex channels controller circuit, the single chip Z80- has four control lines for most com- Second Sourced TR 1953 USART SIO, has been introduced by Zilog, monly used modems. Applications in- Replaces 8251 10460 Bubb Road, Cupertino CA dude fiber optics, microwave trans- 95014. The SIO is designed to work with mission and satellite communications. Zilog's Z -80 microcomputer family and For systems with 2.5 MHz clock rate, also interfaces with most other 8 bit and the SIO's data rate goes up to 550 16 bit processors. The serial 10 con- K bits per second, while in a 4 MHz troller, an N /MOS 40 pin device, is a system, it's up to 880 K bits. Price is peripheral component that can control $49 in small quantities. communications peripherals and format Circle 622 on inquiry card.

Complex Sound Generator Integrated Circuit q ``' Aj I <

222 December 19780 BYTE Publications Inc A "Smar t" VIDEO BOARD VOTI1 e EW -2 001 KIT At A "Dumb" Price! VIDEO BOARD + A MEMORY BOARD + AN I/O BOARD - ALL IN ONE!

STATE OF THE ART DEDICATED $199 NUMBER OF I C s REDUCED BY 0% FOR HIGHER RELIABILITY MASTER PIECE 95 OF ENGINEERING FULLY SOFTWARE CONTROLLED Priced at ONLY Basic Software Included SPECIAL FEATURES: Programmable no. of scan lines OPTIONS: S -100 bus compatible Underline blinking cursor Sockets $10.00 Parallel keyboard port Cursor controls: up, down, left, 2K Static Memory On board 4K screen memory right, home, carriage return (with Sockets) $45.00 (optional)* relocatable to main Composite video 4K Static Memory computer memory *Min. 2K required for operation of this board. (with Sockets) $90.00 Text editing capabilities (soft- DISPLAY FEATURES: Complete unit, assembled ware optional) and tested with 128 displayable ASCII charact- 4K Memory S335.00 Scrolling: up and down through ers (upper and lower case alpha- video memory numeric, controls) Basic software on ROM . S20.00 Blinking characters 64 or 32 characters per line Text editor on ROM .... S75.00 Reversed video (jumper selectable) Provision for on board ROM 32 or 16 lines DEALER (jumper selectable) CRT and video controls fully programmable (European TV) Screen capacity 2048 or 512 INQUIRIES WELCOMED Character generation: 7 x 11 dot matrix

8080 SUPPORT CPU ASCII KEYBOARD KIT $74.00 8212 $3.00 A SOSO $7.75. 8214 7.95 8216 3.50 8228 5.95 RAM -2114 8251 7.95 1 Kx4 450ns 8255 8.50 $8.00 Additional Improvements: Double Size Return Key GROUNDED WIRE WRAP WIRE Computer Grade Control Characters Molderd on Key Caps A.C. CORDS KYNAR 28 AWG Capacitors Power: +5V 275mA OPTIONS: $2.95/100 Feet 5000 mfd 60VDC Upper and Lower Case Metal Enclosure Painted 6 Ft. -$1.19 Blue, Red, White $1.50 Full ASCII Set Blue and White $27.50 $ EDGE CONNECTOR WIRE WRAP PINS 7 or 8 Bits Parallel Data 18 Pin Edge Con. 2.00 44 Pin $1.25 - 72 Pin $1.75 - 100 Pin (S -100) $5.45 Optional Serial Output I.C. Sockets $ 4.00 Serial Output Provision MISC. Selectable Positve or IC's CMOS LINEAR Transistors (Shift Register) $ 2.00 & Diodes Negative Strobe, and DM8810 3/$1 4011 6/51.00 I.C.'s Strobe Pulse Width DM8210 $2 ea. 2N3906 7 /$1 Upper Case Lock Switch for 4022 2/$1.70 LM320K-5 .99 N8TI5 $1 ea. 2N4400 9/$1 2 Key Roll -Over Capital Letters and Nos. $ 2.00 4023 4/$1.00 LM320-12 .99 2N403 9/1 9024 2/$1.50 Assembled (on Sockets) 4071 5 /$1.00 LM709N 11/$1 2N22222A 4/$1 3 User DEfineable Keys 93L08 $1.50 ea. 1N4003 12 /âl and Tested $90.00 93L09 2/$1.50 LM710H 6/$1 1N4005 10 /$1 P.C. Board Size: 93L24 $1 ea. LM711H 6/$1 1N4148 14/$1 17- 3/16" x 5" LM741M 7/$1 SCR 400V 4A, T0220 $ .80 APPLE II I/O BOARD KIT SHIPPING: Keyboard and Video Board: $3.50; nnnRs 125 Plugs Into Slot of Apple II Mother Board

California residents add 6% sales tax 18 Bit Parallel Output Port 1 free software listing for ELECTRONICS WAREHOUSE Inc. (Expandable to 3 Ports) SWTP PR40 or IBM selectric 1 Input Port PRICE: 1603 AVIATION BLVD. 15mA Output Current Sink 1 Input and 1 Output - REDONDO BEACH, CA. 90278 or Source Port for $49.00 TEL. (213) 376 -8005 Can be used for peripheral equipment such as printers, 1 Input and 3 Output WRITE FOR FREE CATALOG floppy discs, cassettes, Ports for $64.00 Dealer Inquiries Invited Minimum Order: $10 paper tapes, etc.

Circle 130 on inquiry card. BYTL December 1978 223 A System for Data Handling What's New? SYSTEMS The VP (video processor) series is a complete computer system with standard interfaces for expandability. The basic unit includes: video monitor, A Single Board Microcomputer System encoded keyboard, minifloppy disk drive, 32 K bytes of programmable memory, serial RS -232 port, four counter timers, printer port, 16 programmable IO lines, and a Z -80 processor. Interface electronics and card cage are available for use with S -100 boards. The main processor board allows expansion to 48 K bytes of programmable memory, 8 K bytes of erasable read only memory, four additional counter timers, and 48 programmable IO lines. The disk controller works with either 8 inch (20.32 cm) or 5.25 inch (13.34 cm) floppy drives and supports three additional drives. All VP series units include a video display offering programmable screen formats with up to 80 characters per line and 24 lines per frame. The video processor has graphic capabilities and supports an optional light pen. Reverse video, blinking and highlight for single characters or fields are included, as well as an underline or block cursor. The entire VP series includes the CP /M disk operating system. Also available are several BASIC interpreters and the C -BASIC compiler. Text editing and assembler are included with the software. The smallest system, VP -80, includes 32 K bytes of programmable memory. It is available to dealers and educational The SYM -1 is a complete micro- byte read only memory system monitor; facilities for $3995. All units are as- computer including keyboard, display 25 general purpose input /output (10 sem bled and tested. Contact Data World and operating software. Some of the lines; SUPERMON software system; Inc, Ravensridge Dr, St Louis MO hardware compatible with KIM board 7541 features of this stand -alone system 63119. include a SY6502 microprocessor device; and more. Other hardware features Circle 627 on inquiry card. 1 K bytes of user programmable include oscilloscope output display and memory, expandable to 4 K bytes in four general purpose 10 buffers. board sockets; 28 key audio response The SYM -1 is priced at $269. Con - Low Priced Microprocessor Comes keypad; RS -232 and current loop tact Synertek, 3050 Coronado Dr, Santa Completely Assembled interfaces allow operation of the system Clara CA 95051. This complete ready to use micro- with video or Teletype facilities; 4 K Circle 626 on inquiry card. processor offers an economical solution for both scientific applications and industrial usage. The MICRO -68 com- New Microcomputer System puter system is priced at and from OSI software for the 6502, 6800, 8080 or $495 Z -80. comes completely assembled. Built Its features include: single chassis around the Motorola /AMI /Hitachi 6800 construction, which can be either table- processor, the MICRO -68 comes with top mounted or rack mounted, including its own integral power supply, 16 button dual 8 inch floppy disks for 500 K bytes keyboard, 6 digit LED display, and of on line storage, 32 K bytes of static 128 words of programmable memory. programmable memory, one RS -232 The 512 MON -1 Bug programmable port, and Ohio Scientific's triple pro- read only memory contains all the ser- cessor board which supports the 6502A, vice necessary to load programs easily, 6800 and Z -80 processors. The system inspect and edit them as necessary, comes complete with a 6502 disk insert break points for debugging, and operating system and BASIC for disk execute. Memory expansion to 64 K and multiple processor switching soft- bytes and full 16 bit input and output ware. The unit features modular con- can be obtained via the edge connectors, struction with an 8 slot mother board, which are provided for. All of the mem- Ohio Scientific has announced a new of which only four slots are used in the ory lines of the MICRO -68 can be buf- microcomputer system, designated the base machine. Additional options in- fered on board. The MICRO -68 comes C3 -OEM. Its applications include use as clude: additional memory, a 16 serial in a hardwood cabinet with a transparent a general purpose computer or controller port input and output (10) board and smoked Plexiglas lid. The unit measures in large equipment such as medical diag- a 96 line parallel 10 board. 9 by 16 by 2 inches (22.86 by 40.64 nostic equipment, scientific equipment, Single unit price is $3590. Contact by 5.08 cm). Contact EPA Electronic analytical equipment and industrial con- Ohio Scientific, 1333 S Chillicothe Rd, Product Associates Inc, 1157 Vega St, trol applications. It is also suited for Aurora OH 44202. San Diego CA 92110. small systems software since it will run Circle 628 on inquiry card. Circle 629 on inquiry card.

224 December 1978 © BYTE Publications Inc DIODES/ZENERS SOC KETS /B R I DG ES TRANSISTORS, LEDS, etc. 1N914 100v 10mA .05 8 -pin pcb .20 ww .35 2N2222 NPN (2N2222 Plastic .10) .15 1N4n05 600v 1A .08 14 -pin pcb .20 ww .40 2N2907 PNP .15 2N3906 PNP (Plastic - Unmarked) .10 1N4007 1000v lA .15 16 -pin pcb .20 ww .40 2N3904 NPN - Unmarked) 1N4148 (Plastic .10 75v 10mA .05 18 -pin pcb .25 ww .75 2N3054 NPN .35 1N4733 5.1v 1 W Zener .25 22 -pin pcb .35 ww .95 2N3055 NPN 15A 60v .50 Ti P125 PNP 1 N753A 6.2v 500 mW Zener .25 24 -pin pcb .35 ww .95 Darlington .95 LED Green, Red, Clear, Yellow 1N758A 10v .25 28 -pin pcb .15 .45 ww 1.25 D.L.747 7 seg 5/8" High com -anode 1N759A 1.95 12v .25 40 -pin pcb .50 ww 1.25 MAN72 7 seg corn-anode (Red) 1.25 1N5243 13v If .25 MAN3610 7 seg com-anode (Orange) 1.25 Molex pins .01 To -3 Sockets .25 1N5244B 14v .25 MAN82A 7 seg com -anode (Yellow) 1.25 2 MAN74A 7 seg corn-cathode (Red) 1.50 1N5245B 15v IS .25 Amp Bridge 100 -pry .95 FND359 7 seg com -cathode (Red) 1.25 25 Amp Bridge 200 -pry 1.95 C MOS - T T L - 4000 .15 7400 .10 7473 .25 74176 .85 74H72 .35 74S133 .40 4001 .15 7401 .15 7474 .30 74180 .55 74H101 .75 74S140 .55 4002 .20 7402 .15 7475 .35 74181 2.25 74H103 .55 74S151 .30 4004 3.95 7403 .15 7476 .40 74182 .75 74H106 .95 74S153. .35 4006 .95 7404 .10 7480 .55 74190 1.25 74S157 .75 4007 .20 7405 .25 7481 .75 74191 .95 74L00 .25 74S158 .30 4008 .75 7406 .25 7483 .75 74192 .75 74L02 .20 74S194 1.05 4009 .35 7407 .55 7485 .55 74193 .85 74L03 .25 74S257 (8123) 1.05 4010 .35 7408 .15 7486 .25 74194 .95 74L04 .30 4011 .20 7409 .15 7489 1.05 74195 .95 74L10 .20 74LS00 .20 4012 .20 7410 .15 7490 .45 74196 .95 74L20 .35 74LS01 .20 4013 .40 7411 .25 7491 .70 74197 .95 74L30 .45 74LS02 .20 4014 .75 7412 .25 7492 .45 74198 1.45 74L47 1.95 74LSO4 .20 4015 .75 7413 .25 7493 .35 74221 1.00 74L51 .45 74LS05 .25 4016 .35 7414 .75 7494 .75 74367 .75 74L55 .65 74LS08 .25 4017 .75 7416 .25 7495 .60 74L72 .45 74LS09 .25 4018 .75 7417 .40 7496 .80 75108A .35 74L73 .40 74LS10 .25 4019 .35 7420 .15 74100 1.15 75491 .50 74L74 .45 74LS11 .25 4020 .85 7426 .25 74107 .25 75492 .50 74L75 .55 74LS20 .20 4021 .75 7427 .25 74121 .35 74L93 .55 74LS21 .25 4022 .75 7430 .15 74122 .55 74L123 .85 74LS22 .25 4023 .20 7432 .20 74123 .35 74H00 .15 74LS32 .25 4024 .75 7437 .20 74125 .45 74H01 .20 74S00 .35 74LS37 .25 4025 .20 7438 .20 74126 .35 74H04 .20 74S02 .35 74LS38 .35 4026 1.95 7440 .20 74132 .75 74H05 .20 74S03 .25 74LS40 .30 4027 .35 7441 1.15 74141 .90 74H08 .35 74SO4 .25 74LS42 .65 4028 .75 7442 .45 74150 .85 74H10 .35 74S05 .35 74LS51 .35 4030 .35 7443 .45 74151 .65 74H 11 .25 74S08 .35 74LS74 .35 4033 1.50 7444 .45 74153 .75 74H15 .45 74S10 .35 74LS86 .35 4034 2.45 7445 .65 74154 .95 74H20 .25 74S11 .35 74LS90 .55 4035 .75 7446 .70 74156 .70 74H21 .25 74S20 .25 74LS93 .55 4040 .75 7447 .70 74157 .65 74H22 .40 74S40 .20 74LS107 .40 4041 .69 7448 .50 74161 .55 74H30 .20 74S50 .20 74LS123 1.00 4042 .65 7450 .25 74163 .85 74H40 .25 74S51 .25 74LS151 .75 4043 .50 7451 .25 74164 .60 74H50 .25 74S64 .15 74LS153 .75 4044 .65 7453 .20 74165 1.10 74H51 .25 74S74 .35 74LS157 .75 4046 1.25 7454 .25 74166 1.25 74H52 .15 74S112 .60 74 LS 164 1.00 4049 .45 7460 .40 74175 .80 74H53J .25 74S114 .65 74LS193 .95 4050 .45 7470 .45 74H55 .20 74LS367 .75 4066 .55 7472 .40 74LS368 .65 4069/74C04 .25 4071 .25 MCT2 .95 LINEARS, REGULATORS, etc. 4081 .30 8038 3.95 LM320T5 1.65 LM340K15 1.25 LM723 .40 4082 .30 LM201 .75 LM320T12 1.65 LM340 K18 1.25 LM725N 2.50 MC 14409 14.50 LM301 .45 LM320T15 1.65 LM340K24 1.25 LM739 1.50 MC 14419 4.85 LM308 (Mini) .95 LM324N 1.25 78L05 .75 LM741 (8-14).25 4511 .95 LM309H .65 LM339 .75 78L12 .75 LM747 1.10 74C151 1.90 LM309K (34oK-5185 7805 (340T5) .95 78L15 .75 LM1307 L25 LM310 .85 LM 340T 12 .95 78M05 .75 LM1458 .65 9000 SERIES LM311 D (Mini) .75 LM340T15 .95 LM373 2.95 LM3900 .50 9301 .85 95H03 1.10 LM318 (Mini) 1.75 LM340T18 .95 LM380 (8-14 PIN) .95 LM75451 .65 9309 .35 9601 .20 LM320K5(7905)1.65 LM340T24 .95 LM709 (8,14 PI N).25 NE555 .35 9322 .65 9602 .45 LM320K12 1.65 LM340K 12 1.25 LM711 .45 NE556 .85 NE565 .95 MICRO'S, RAMS, CPU'S, NE566 1.25 E -PROMS NE567 .95 74S188 3.00 8214 8.95 INTEGRATED CIRCUITS UNLIMITED 1702A 4.50 8224 3.25 MM5314 3.00 8228 6.00 7889 Clairemont Mesa Boulevard, San Diego, California 92111 MM5316 3.50 8251 8.50 (714) 278 -4394 (Calif. Res.) SPECIAL 2102-1 1.45 8255 8.50 DISCOUNTS 2102L -1 1.75 8T13 1.50 All orders shipped prepaid No minimum Total Order Deduct 2114 9.50 8123 1.50 Open accounts invited COD orders accepted $35 - $99 10% TR160213 3.95 8124 2.00 $100 - $300 15% TMS 4044- 9.95 8197 1.00 Discounts available at OEM Quantities California Residents add 6% Sales Tax $301 - $1000 20% 2107B -4 4.95 All IC's Prime /Guaranteed. All orders shipped same day received. 8080 8.95 2708 9.50 24 Hour Toll Free Phone 1- 800 -854 -2211 American Express / BankAmericard / Visa / MasterCharge 8212 2.95 Z80 PIO 8.50

Circle 180 on inquiry card. BYTE December 1978 225 TELEPHONE/KEYBOARD CHIPS 7400 Tit. AY-5-9100 Push Button Telephone Dialler $14 95 S974711 79 /y AY-5-9200 Pep erb ry [Haller 14.95 59747314 29 Ebctronlc HomrVigilite AY-5-9500 OS Clock Genera70 4 95 5974009 16 S9747311 35 56711609 .69 Seanky Timer AV-5-2376 Keyboard Encoder (88 keys) 14 95 1174001 15 5674746 35 53741691 99 7 95 .d P.1»ePwmrva .9N conndmlao las 'b. HD0165 Keyboard Encoder 16 keys) 59740211 15 5674755 49 59741626 1.95 N'nw.a.RY.I.red.dglMarrvraonallyn+xltn MCN-.ae. 74C922 Keyboard Encoder 16 keys) 9 95 5974033 la 5974/69 35 597416314 89 r.andb.gar.oel.n.n9gN+onarHOatn ex x. p.nwn 5974049 la 597479,7 5 00 53741646 89 *le Km rmway EM CHIPS 5974059 20 51974309 50 59741691 89 ICM7045 CMOS Precision Timer 24 95 Ww.m orner wy11. 597406h 29 59711329 99 59741669 1.25 ebnrmrNcaum.n ranvnwlalaeywq ICM72C5 CMOS LEO Slopwalchnimer 19 95 MINA" drn.arwwnraomaaml.swdpl7u.« w9418.40450 5974076 29 59141339 59 59141619 1.95 ICM72C7 7.50 wrwaa 4015 lchormrl.rwr.ram77 7rv«viPel.v.r.. Oscillator 00,009er 5574097. 20 5974859 79 59741109 1 59 ICM72C8 Seven Decade Counter 1995 w.n9 Hawn. lmlikoom and 7.5cam 4975n9 NM P. . rdrrl. 5974099 20 5714867. 35 597417213 6 00 I. MOM*, VAN l.awn Iw ICM72C9 Clock Generator 6 95 1 75 pock .11, mom 5N7110N la 597413914 59741736 1.25 44.4444.4411 Ne a 110 rom. Menke.":' 1p< 5974119 25 5671909 45 567417/3 89 ^ . c m O r l p e ISM 7A dun m.» 1 Me MA. wrMy m. NMOS READ ONLY MEMORIES A48e..71.467 noam.lHome 557/726 25 5971994 59 567/1756 .79 MCM6571 128 X 9 X 7 ASCI Shined with Greek 13 50 5674139 40 5974979 43 54741764 .79 MCM6571 128 X 9 X 7 Math Symbol A Pictures 13 50 E.1 to n.x'i, m. Vq r. uno r.W Hn+ r wiw7M VIM LEO CMC.. 5974146 70 5914939 43 59741776 79 Part Number 13 W s P. wW wnwe n,deqtl.nr WNnV pamm rd 7.ndm pA+ MCM6575 128 X 9 X 7 Alphanumeric Contrd 50 S47116N 25 517416 65 59741796 I 95 Nam e. w,aourdepodr W!+. M-ro.d.dH.mw Character Generator 5974176 25 174959 65 56141806 79 aar.. a1w. o,e ow vox. W aw rKa6.ue VGL-1 59/+209 20 5.74966 65 59741819 1 95 MISCELLANEOUS 1.7717,7.7157774077,350775 S974219 29 5474976 3 00 56747826 79 TL071CN 0uad Low Noise bi-tet Op Amp 2.49 5474224 39 56741009 89 59741949 195 $39.95 ea. Switching 4.49 oMv4G 11 C.wee.u..w .on TL491CN Regulator 5974239 25 59711079 35 591411359 1 95 eorx , w wro TL496CP Single Swlching Regulator 1.75 5674754 79 54741096 59 59741869 9 95 ws.P 11C90 Diolde 1071 Prescaler 1995 59147671 29 54741169 1 95 567418136 3 95 ....,ar....aww+myw. 41a.rvl.. tar +o.wr 95090 HI -Speed Divide 10 It Prescalel II 95 54;47'4 25 53741219 35 56741907, 1 25 4533 Photo -DarienQ Ion 0pto- 110!3101 3.95 597/2974 39 54741226 39 59711916 125 MI(50240 Top Octave fre4. Generator 17.50 5974306 56741929 .79 20 54111235 49 DISCRETE LEDS TIMEX T1001 D50025CH 5Mha 2 -phase MOS clock Driver 3.75 5974326 25 55741259 49 59741939 79 111308 red num. display w /rlteg logic chip 10.50 -200 dl a. 2r 5974376 25 59747269 49 59741941 89 LIQUID CRYSTAL DISPLAY MM5320 TV Camera 55eIc Generator 14.95 75 69 X05566 red 5/51 .125 dl.. FIELD 597438,7 25 59741323 5,7711956 EFFECT MM5330 5'7 Digit DPM Logic Block 5 95 XC556G green 441 XC2C9R red 5.51 5,771391, 25 5.141314 75 5,774196,7 99 10110 111 3'2 091 0,0 Convener Set 25 00 set XC556Y yellow 4/S1 XC209G 4 5h7 i6N 20 5,771141,7 79 5374197,7 99 green 51 e a 5,7141989 I 49 XC556C clear 4101 XC2C9Y yellow 4/S1 76477 5674417. 89 59747429 1 95 LITRONIX ISO -LIT 1 SN 54741994 1 49 .200- dla. 5674426 49 56711136 2 95 .185- dia. Photo Transistor Opio- lSolAor SOUND GEN B1A106 5474436 75 567414111 7 95 59745200 4 95 XC22R re0 5/51 XC526R red 5/á1 llllP (Same as MCT 2 or 4N251 Generates Complex Sounds 59.1446 75 517/1/51 19 59142519 1 79 XC22G green 4/51 XC526G green 451 Low Power . Programmable 5171+59 75 514741479 1 09742799 79 XC22Y yellow 4151 95 XC526Y yellow 451 40.017 5- CHARACTERS 5674466 69 567/1/81, 129 597428371 2 25 dia. 2/99¢ .170' XC526C clear 4/51 THREE ENUNCIATORS 3.95 each 5h714711 59 53741503 89 097471349 3 95 MVIOB red 4 /SI 2.00" X 120" PACKAGE GAME CHIP AND CRYSTAL 5674407. 79 59741579 59 54712654 3 95 .190- dia. TV .085' dia. INCLUDES CONNECTOR 5674506 59747579 69 XCI71R red 5/51 69-3 .8500- I and 2 01 MHZ Crystal (Chip 5 Crystal 10 59 59743659 M050 red 631 5974519 20 55111536 59 59743666 69 %CI I7V green 4/51 T 1001-Transmissive 57.95 induces score 47splay. 6 games and soled angles. etc INFRA RED 7.95 /Set 541+534 70 54741514 99 91743676 69 LED %C7 yellow 441 T1001ARellective 8.25 I,4- .114- x1/16- Ilal 5474544 20 597115574 79 59743686 69 %0111[ Uear 451 092C5 53.40 XR2242CP 1 50 541 XR21C 4.40 4 5,774594 25 S717/1563 79 59743909 1 95 X62264 25 5974609 20 59741576 65 59743937. 195 X6215 4.40 X62556 3 2C DISPLAY LEDS X6.320 1.55 EXAR X62567 2 99 20% Obcoun1100 pp combined order 25% -1000 pee combined order X6.1555 1.50 063403 1 25 TYPE PO AMITY NT PRICE 17PE POLARITY NI PRICE 01555 39 591800 3 20 864136 125 C04000 23 00,070 ;5 MALI I Commot Anode +en 270 2 95 IAN 6730 Common Awee.'ed _ I 560 99 99 192208 4 40 X64151 2 C04001 23 C/MDS C04071 MAN2 5 a 1 Dot MaS+.eI 300 4 95 AR/ 6740 Common CJ17ode-red.0 0 580 99 X0.556 85 49 XR567CP 99 X62207 3 85 X64194 1 45 004002 23 004028 89 [D1072 1144 3 Common Calhaerred 120 25 IAN 6750 Common Cale9 de-red : I 560 99 X6567CT 1 25 092208 064202 3 004006 1 19 CD4029 1 19 0040'6 1 39 MAN 4 Common Camdd,red 187 195 MAN 5760 Common kW e-red 580 99 5.20 60 CD4007 25 C04030 C040131 23 XR1310P 1 30 092209 1.75 X64212 2 05 49 6411 7G Common Anode-Breen 300 1 25 6p9 6793 Common C,Inodo-red 99 XR1468CN 3 85 892211 C04009 49 CD4035 99 03+082 23 MAN TV Comma, Anodeyelow 300 99 0171 Common Allode. red I 300 99 094556 75 49 X61488 1 39 X62212 1 15 C04010 [04040 7 19 [0409' 99 VAN 72 Common 0131777* 300 99 01704 Common Camodred 300 99 áá5 X64139 1 1 2.49 091489 39 012240 3 45 864741 117 CD+m1 23 cD4041 25 [04098 MAN 74 Common 041770 a led 300 1 25 04707 Common Modeled 300 99 25 99 MCII109 14 95 003012 CD4012 Anorlt LOW 1 49 MASI 82 Common 4e 300 99 06728 Common Cahod -red 500 TYPE VOLTS W PRICE C01013 39 COITO 14 95 MCII/10 MAN 5/ CommHCa000e -wlbw 300 99 01141 COmow44,00e -led 1 25 DIODES 914007 100 PIV I AMP 12'r 00 CD1014 139 C04044 as MC11411 14 95 MAN 3620 Common AnoOe.oran3e 300 99 04746 Common Mode -red _ 1 630 149 1701.19 TRE W PRK5 194003 200 PII I AMP 12100 CD4015 1 19 CD4045 1 79 MC11.119 95 MAN Common Anode-orange 1 300 99 red 3630 I 01747 Common Anode 600 1 19 400m 76/46 33 4100 16+001 400 P701 AMP 2 1 D0 [03016 49 [D4047 2 50 M[14133 19 95 MAN Common 3640 eahod -wanpe 300 99 OLI49 Common CaIodered - 1 630 1 49 79751 400m 51 4100 19+005 600 PII I AMP 10 1 CO 003017 1 19 [040+8 135 M[11$06 75 MATI 4510 Anode 300 red Common orange 99 0L750 Common Cal *71 600 1 49 1,7752 5 4 6 4COm 100 11,40116 800 NV 1 AMP 10 100 C040113 49 MC11507 99 99 CD4049 MAN 4640 Common Ca1154e ual9e 400 99 0033B Common Catnode.red 110 35 11,753 62 4001 41D3 814007 1000 PIV 1 AMP IO 1 00 CD4019 19 001050 19 Mc14562 11 50 MAN 4710 Common Anode -red 400 99 F1,070 Common Cathode 250 69 94751 6 e 4001 111 00 ,1,3600 50 200m 6100 004020 119 C04051 119 MC14583 3 50 I MAN 4730 Co-mow, Anode -red + 400 99 117,0358 1 Common calked - 357 99 4 1 11341411 111757 913 400. 00 75 6111 15 1 00 004021 1 1 39 CD4O53 19 C3/5Ce 3 95 MAN 4740 Common Catl,noereS 400 99 F90359 Common Camode 357 75 11,759 12 0 400. 4 1 00 161151 35 1077 17 I OC 19 004022 1 CD4056 2 95 031510 139 MAN 4810 Common Anodeye+ow 400 99 760503 Calhade(9105001 500 Common 99 B 2 4 1 13959 400. 00 114305 75 2577 IS 1 00 1 MAN 4843 [34023 23 [04059 9 95 C1511 29 COrNrlan Calhod yePO0 400 99 17.3507 Common Anode IF 505101 500 99 14965 15 40071 4 1 00 134734 5 6 IA 28 79 19 004024 LD4060 1 c0/515 2 95 MAN 6610 Common Anode -orange+) 0 560 99 50827730 Anode.rea Common 300 I1 165232 5 6 500. 28 471735 6 2 Iw 2a C04025 23 79 c04518 129 MAN CD1O66 6630 Carnal Andeorange _ 1 580 99 I1415P 3430 COmmm Anode-red 500 2 10 145734 E2 500,. 28 1134736 6 8 1w 2a [04026 2 25 CD40fi8 39 CD4520 1 29 MAN 6640 Common CelhodeoIange-0 0 560 99 HOSP 3403 Common Cathode red 930 2 10 135235 6 8 500m 28 074738 a2 1w 2a 074027 69 CD4069 45 C04566 2 25 MAN 6650 Common cathode-orange 1 560 99 50827300 4 a 7 141 01011 RHO 600 19 95 165236 7 5 50077 28 191742 12 Po 2a MAN 6660 Common Ann /e-orange 560 99 S082 7302 4 7 591 004.4407 600 19 95 195242 17 50077 28 16+744 lí 28 74 COO 39 74[183 2.49 MAN 6580 Common CAhodorange 580 99 5082. 304 Overrange 37713[717 11 503 1500 74C00 74[164 (_ 815245 15 5W'n 28 1911133 50 PI1135 AMP 1 60 7{02 39 2 49 AIAN 6710 Common Anode +ed -0 0 560 99 5382.1340 4 17 591 o,on.Heudennal 600 22 50 16156 25 40m 111181 100 74004 39 71085 2 49 74[173 2 5 6100 P1035 AMP 170 7m 1%58 150 6100 161185 158 P135 AMP 1 74C0B 49 74090 1 95 7/C197 219 70 194854 180 10m 5 , DO 1141186 200PIV3S AMP 1 180 74C10 39 74093 95 74[193 2 49 RCA LINEAR CALCULATOR CLOCK CHIPS MOTOROLA 154001 507101 AMP l7100 1141188 74C14 1 400 PIV 35 AMP 3DO 95 71C95 1 95 74C195 2/9 CHIPS CA30131 2 15 CA3082I1 2 00 /DRIVERS 995309 S4 95 MC140817 SI 95 14C20 74C107 39 175 740922 5 95 4 95 CA20231 2 56 C430836 150 995725 52 95 9615311 MCl/OR8 5 75 74C30 39 740151 2 90 74[923 6 25 SCR AND FW BRIDGE RECTIFIERS CA3035T 2 995312 4 95 M[1439- 2 95 45 CA30851, 85 995735 2 95 15A:1 74[12 195 71[154 3 00 74C925 5 95 MC3022P 6360 1009 SCV,, 018191 51 95 CA3039T 1.35 CA30671 3 75 DM/569 2 00 9745014 4 95 2 95 74C48 249 740157 2 15 740926 8 95 C38M 3511-101 5CR 195 CA3016N 1 30 CA31307 1 995316 695 903061P 3 50 7.473 49 39 D619865 1 00 89 740160 2 80[95 150 MM5318 7767370 16A 191 300', CA3059N 325 CA3140T I25 095887 75 995 M10161744161 7 50 SCR SO 74[71 89 74061 2 +9 80097 SO 74745369 MC1071P 3 95 MOI 9 0 I 126 .. 711V 0430035 3 25 [A3607 1 25 DMSSB9 75 795 FW 8ß106E REC 1 95 78MG 9!4533' i91-4 4 I03A 175 LM7104 79 CA3080T 85 CA34019 49 9374 7 sog 95 MCIOJOP 6 95 980 3 '2A 7005 FW BRIDGE REC 195

99 1 MM5611 9 95 4 141066 LINEAR LM711N 39 CA3051N 2 00 0A16009 3 50 C A LED dover 50 MC4044P 50 1.31.3009 80 697239rH P112907 PMsIX LM340K 18 1 35 55 7/1 00 TRANSISTORS 27.390+ 100 IC SOLOERTAIL LOW PROFILE (TIN) SOCKETS , LM3111C9M 35 LM7336 I.00 - C10681 r,. 1 50 97E3oss 263905 L93404-24 35 1.24 2549 5C100 100 1M302H 75 LM739,7 119 1-24 25-49 5C-100 MPSA05 30 L914137 1 25 293392 5100 263906 4 l'In I pan LP 517 16 15 22 S 37 IM3341 1 00 p. LP 1.M3401.6 125 LM74106 N 35 36 35 MPSA06 51100 29339a 5100 261013 31uu pol LP 20 19 18 24pinLP 3 1033511 37 71597 1 60 LM3401 8 1.25 L9741-146 39 36 6 00 13567 1 100 244173 6100 16 LP 4 H 35 pn 22 21 20 28 pin LP 71598 LM30701 L713407-12 1.25 L9747311 79 44 43 6 100 P313568 4:I00 P1,1249 4100 LM308C4 le pm LP 29 28 27 36 60 .H 100 1M3107-15 1 Dn Se 90409 25 197499 H 39 59 1 75 PN3569 41 00 P61250 /11 00 20 pn LP 34 37 63 14301 110 193401.11 30 10 pin lPLL PP 62 1 25 LM13106 2 95 SOLOERTAIL STANDARD (TIN) 61 40410 1 75 6195363134 S11 00 2991400 /n 00 193098 1 25 1M3407 24 10573 75 125 LMISBCN H 59 99 51 I MP53702 5100 264401 4100 14pin5T 527 25 24 1111111 2aprnsr S 90 LM31001 1 15 191589 100 MC188N 195 29918 4 1 00 293701 76 Din ST 1 3 1 76 1.15 5100 264402 4100 151311911 9p 16pnsr 30 27 25 1313704 195 MC14B9N 2922191 2100 9P53704 1 195 1.6 1 45 5 00 264403 4100 la pm ST 35 32 30 40 ín51 130 LM312H 195 1M37371 3 25 11114969 95 2922214 4100 293705 5100 254419 5100 L613171( 6.50 24SMST 49 45 12 SOLOERTAIL STANDARD (GOLD( L93773 4 00 LM1S56V 1.75 2922224 5100 MP53705 5 100 295096 4100 S 63 LM31BC6H 150 1.93804 125 MCI7415CP 300 57 2112169 5100 263706 5100 265067 1100 515 530 27 29 26 pIn SGS I 1 1613194 130 LM3BOCN 99 1921111 195 100 90 7112369A 4 I DO 114153706 14a 5100 265085 4100 51150 35 32 29 16 1M3206ó 135 36 on SG 1 40 1 76 9E57359 1.4138111 179 16129019 295 5 1 00 243707 110U 6 pin SG 38 32 5130 265059 1 35 10 1.7 145 LM3206 .5 2 35 1 79 pn50 1.59 262484 L1A3826 L1130533 150 4100 263711 5 I 00 295129 ta pen SG 52 17 43 51CC LM320112 1 35 965076 a 00 LM30656 149 WIRE WRAP SOCKETS 292906 4100 2937244 65 P135131 5100 1IÁ12014-15 I 35 147104 6 0] LA09011131011 49 242,107 31 00 22PmWws.95 85 15 2713125A 100 P55138 5r00 1032011.11 135 aP6vow S 39 35 31 LEVEL 43 14529A 4 95 0939056 59 (GOLD) 252925 5100 263772 2 1OpnWW 45 41 37 21 pin WW' 105 95 85 25 755139 5100 1.3132124 1 35 395 L439099 125 113E2955 I 25 NE531110/ 1 25 1 10 293523 I 00 i pIn PAY 39 38 37 ?BP nWW 140 265210 5100 160201-5 125 0113551* 763053 2 I 6E5361 600 59 00 263903 1 16pin1NY 43 42 41 36pnWw 159 145 1 30 S 100 295149 3 20 0743201,5 2 1 25 9E5401 4 600 80385 95 1 753055 69 P62727 P71375 71 1 18pnwW 75 68 62 40prnww 175 I 55 40 30 7N5951 h 1131018 1 25 ME5414 4 95 L11754509 49 - 1 1507201.12 25 N65SON 1 30 '545116 39 1 UISCCAPAGT0R15 L31720145 25 NE555V 39 T5152CN 39 CAPACITOR CORNER 1/4 WATT RESISTOR ASSORTMENTS LL,... 1 -5% 0 am _ LM32o1-18 25 NE5561 99 75453[. 39 !.4 00M CHr.7 153 1111.1 EMU 10 HI OS 04 103201.24 1.25 6E5608 5 00 7545101 39 03 0010F 05 Ó44 035 ASST. 1 5e. -.iì18.1 3) HM 19 HM 545 334.411 22 p! 05 04 03 0047PF 05 LM323X-5 5 95 9E561B 5 00 15491C9 /9 11MM SO PCS $1.75 04 035 47 pl 05 04 03 01P5 19324N 1 BO 05 04 033 365626 500 7549211 89 651171.1 e2 OHM WO OMM 17p tow 15p 1'.71.1 100 PI 05 04 03 0220 06 05 04 LM339N 99 4E5656M 125 154935 89 ASST. 2 5.4. 15o Cam 220 OHM !IT OW 3104mM 39001W so PCS 1.75 220 pl 05 01 05 0470" OE 05 04 1 1M31065 35 1 75 6E5G501 7549+14 89 17001 05 04 IPF 170 ERA 567 OHM reto 114M 035 12 09 075 19340K.5 1 35 RC4156 IVO 1X14 r 65567V11 99 1 25 F30493195699 FILM CAPACITOLe 3 1. 1}6 1M34IX41 1.35 NE5709 4 95 RC1151 5 95 ASST. Sei, 1.8e / so PCS 1.75 12 001n'1 10 07 022.1 13 11 Oa LM340512 1 35 LM7031M 69 RC1194 5 95 3.314 3.9. 1 :6 5 7. 0022 12 10 07 04,1 21 17 13 1934061$ 135 1M709N H 29 804195 4 49 8847m1 12 10 07 11F7 77 23 17 ASST. 4 5 ea a 2. lOk 124 153 E18. 50 PCS 1.75 01.1 12 10 07 229 33 741500 23 1/15138 69 27 72 726 216 13a. 197, 170 420`/. GIPPED TANTALUMS I901101 CAPACITORS 741507 23 74LSOOTTL 7415139 69 1/391 78 23 17 15/356 ASST. 5 5 e. 56k 666 873 ION 120? 50 PCS 30 26 21 744502 23 741547 69 7415151 69 1.75 15/755 25 23 17 22/755 31 27 27 74503 23 741551 23 7415155 69 1904 160k ??0k 2706 711 22.754 75 23 17 33,250 31 27 27 711504 29 741554 23 745157 69 ASST. 6 5 ea 3901 470k 561 681 571 50 PCS 1.75 33 350 20 23 17 4 7125 12 716505 29 746555 23 1415160 89 4.7.350 1,2M 28 23 17 6 8 250 36 3e 25 1U I 56 I.I1 2.:61 740508 23 716573 35 1415161 89 58.350 20 23 17 10 25V 40 35 79 746574 ASST. 7 5 ea 2.7M 3.0M 1.954 17M 5.151 50 POS 74509 29 35 7415162 .89 1.75 1.01350 28 23 17 15 25V 63 50 10 141575 711510 23 49 7415163 89 MIMATURE ALUMINUM ELECTROLYTIC CAPACITORS ASST. OR Includes Resistor Assortments 1 -7(350 PCS.) $9.95 741511 W 741576 35 7415161 99 ea. A.lai 1aa 6491.11.513 74013 49 741576 39 7465175 79 17 51 15 13 10 47 755 10 71514 99 741583 75 7415191 249 55.00 Minimum Order - U.S. Funds Only Spec Sheets - 251( I 0 505 16 14 II 47 50V 16 14 11 741515 29 741595 99 7415190 89 California Residents - Add 6% Sales Tax 1979 Catalog Ayallable -Send 410 stamp 3 3 50V 14 12 09 1D165 15 13 10 1 1 25V I 741520 23 7413136 35 745191 89 S I3 10 1 0 255 16 11 11 10 250 15 13 74521 29 741590 49 7415192 89 10 I 0 505 16 11 11 10 50V 16 14 12 1 1.16V 15 13 741522 29 741592 .59 7415193 89 PHONE 10 2/25V 17 15 12 4 7 250 15 13 74526 29 741593 59 746519+ 89 sO9f 10 9 2- 50V 24 20 113 1.7 ORDERS 51 16 14 II 741527 29 741595 79 745195 89 /71250 19 17 15 10 165 11 12 09 29 741596 89 7415253 79 74528 ,g1 --' arreco WELCOME 47.50V 25 21 19 10.75V IS I3 10 71530 23 7415107 35 790257 69 100 25V ELECTRONICS (415) 592.8097 24 20 18 10.500 16 14 12 79532 29 7/15109 35 7415258 1 39 100,506 35 30 75 4750V 24 21 '19 7165112 35 7415260 71537 35 55 220 21 32 28 25 1011 16V 19 IS 14 74540 7/60123 99 7415279 41 29 59 MAIL ORDER EL /:Cl ROVICS WORLDWIDE 220.50i 45 38 1125V 24 20 18 - 470755 741542 69 7413125 69 7465367 59 33 79 77 100 50/ 35 30 28 1021 HOWARD AVENUE. SAN CARLOS. CA 94070 1000 164 7415132 79 7485368 59 SS 50 IS 220 1130 23 17 16 7415136 39 715670 195 Advertised Prices Good Thru December 2205165 70 67 55 470.71 31 78 77.

226 BYTE December 1978 Circle 200 on inquiry card. MICROPROCESSOR COMPONENTS The Incredible

mnA /BORIA SUPPORT DEVICES CROPROCESSOR MANUALS BOSON ELECTRONICS CPU S 995 M -280 User Manual 6750 "Pennywhistle 103" (JamecoKjtS 8212 6.011lnpv 3 25 :ONput M-COPiE02 User Manual 7 50 8214 Priority Interrupt Cmlrtl 5 95 M.2650 User Manual 5 00 8216 & -0ieckmul Bas Driver 3 49 Regulated Power Supply 9224 Clock Generator/Dryer 3.95 ROWS ame Bus Drver 3 49 $139.95 Kit Only 2513(2140) Character Generalor(upper case) 5995 9228 System Driver is born . Uses LM 309K Connoenam 595 2513(3020 Character Generalorybwer case) 9 95 TM P. ely*Metla 103 capable of letorae8 data lo and aua.o ape 011.00 8238 System Controller speed Ieq recorder a nor ln able lo Heat 595 2516 Character Generalor 1095 curial alemmislorine Communicate downy n;h . sink provided 8251 Prog Comm 1N(USARTI 795 M/A5231e4 2016111I Read Only Memory 1.95 anolher modem and terminal lu telephone ' hamming and comnuntadom In . P.C. board construction 8213 Rog Interval Timer 14 95 addition .illslreeolcmic aladIaSlm.nt5 andts builtwlhiron precision. reaOEyavnable 8255 Rog Pernh 1 /O(PP5 995 RAM'S pads Provides a solid 1 amp ÇL . 8257 Pro! DMA Control Oa. Trenamiutm 1w VIS ..... 1995 1101 256 91 sulk SI 49 Freg1Rcy-5hil1 Keying. lull. duplex pue -duplex 5V 8259 Rog. Interrupt Conlml seleclablel 1995 1103 102461 99 Mlll Oats Rat. 306 Baud . Includes components, 01007/100 SUPPORT OEVICES 2101(8101 25694 Sc51.1e 3 95 MC6100 MPU S14 95 Oils Format Asynchronous Seral Irelurn lo mark level required hardware and instructions 202 1024 %1 Sape 1.75 1,C692CP M'U WIE Crock and Ram 2415 21107 102491 SIMIO 1.95 bellaeen each 16.110len Fregwreles Sizes. 3 -1/2" x 5" x 2" high MC6115911 1208 s1Mic Ram 5.95 2111(1111) 25604 stalk 395 Receive Chenal 2525 Nt la apace. 2225 He la mark Transmit Channel Fn MC6B21 Perrph Inlet Amp1(MC6820) 74! 2112 250(4 Slalic MOS A95 menton Shaikh selected. Low (normal) 1070 space, 1270 magi High space. 2225 mal. IAN828 Rmly Inentpl Controller 1295 2114 102194 Slat. 450ms 9 95 on Read. Seoul*Ky -46 Wm auousleally coupled JE200 $14.95 MC583S4.11 102498 Bee ROM (MC671A3S.9) II 95 21141 102404 Rabe 450ns low power 1095 Tr.namo Level 15 dOm nominal Ad,elable horn -6 06m 9C6950 Asynchronous Comm Adapter 795 2114 -3 102464 Sat. 300m 10 95 Io -20 d6m MC6852 Synchronous Serial Dale Adapt 995 2114L -3 1024 %4 Static 350ns low power II 95 MC6860 IwO&O. Fr.wency 101191040 _frequency rekrence aulorwlically adults lo Function Generator Kit 0.600 bps Oional MODEM 12 95 5101 25664 Rmc 795 Wow for operation between 1800 Ha and 240310 616862 2400 Bps Mo& 4IW 14 95 52102107 409691 Dynamic 4 95 0191)11 Data 15111K5 BIA 05.232C or 20 m9 ear mil loop 41 MC6810A aced 3SIave Bus. Trans (ÁC9726) 2 25 7489 1694 Stato 1.75 (receiver . Provides 3 basic wave- 00010 kled and non -pilon MICROPROCESSOR MSCELLANEDUS 745200 256 %1 Static 4nslal5 4 95 CRPS- Power RyalnreeMs 120 VAC. singe phase 15 Wens forms: sine, triangle & 93421 256 %1 514.. 2 zaogeoC) CPU - 95 - 51995 POFekS All components mount on a by UP0414 4K Dynamic 495 ongle 5' 9' square wave 2909(280.1) Cm 2495 16 pin (M84027) wow board MI components m.I1ád COP1802 CPU 1995 RirtsReal/lies a VOA, Audio D:Cila101, Frequencyeguency Counter and/or . Frequency range from 1 Hz UPD416 168 Dynamic 16 N 95 DsulmaPe t ago 2650 MPU 1995 pin 1MK41161 to 100K Hz 8035 994 MPU w clock RAM 1/0 Ines 1995 TMS4044- 4K Slal c 1a 95 P8085 CPU 1995 Output amplitude from 4511. TU5990011. 16.Bí, MPU w/hamw *e. multiply TRS -80 16K Conversion Kit íM54015 0 -volts to over 6 volts &dude 4995 102494 51x14 14 95 2117 16.38491 Oyna1.c 350m 9 95 Expand 4K TRS SHIFT REGISTERS your -80 System to 16K. Kit (peak to peak) pane marken 1651500H Da 25 B4 Dynamic comes complete with: Uses a 12V supply or a t s 61115262 no Dynamic 4 1.00 M05031 Rai 50 &I Dynamic 6V split supply 9946049 Dual 16 &I Slate. 50 ' 8 each UPD416 (16K Dynamic Rams) M45069 Clod 100 &t SMOG . Includes chip, P.C. board, 50 PROM'S Documentation conversion MM510H Dual64 Be kcuenualor 50 for 1702A 2018 FÁ605 5595 components and instruc- MM5016H 500512 91 Dynamic .89 11452516 1611' E9909(4151 2716) 49 95 25041 1024 Dynamic 395 tions. (2716) 'Rewires single 05V power supply TRS -16K $115.00 2518 Rex 32 B4 Static 495 1M52532 4948 EPIOM 8995 Special Offer - Order both your TRS -16K and the 2522 Oat 132 Bee Slatc 295 270B BK EPROM 10 95 JE2206B $19.95 2524 512 SRI. 99 Sup'R' MOD ll Interface kit together (retail value 2716 4.1 16K' EPROM 2995 2525 024 Dynamic 295 'Wewtres 3 robages -5V..5V, .12V $144.95) for $139.95 2527 Oua1256 &I Slat c 295 only 5203 2048 F1105 14 95 2528 Stat 250 State 400 6301 -1(7611) 1024 11181 Bunter 3 49 Digital Stopwatch Kit 2529 Dual 240 &1 Slat. 4 00 6330. 97602) 256 Open C &boar 2 95 292 aad BO Bo Slati. 2 95 12523 71x4 Open Collector 395 COMPUTER CASSETTES w 2933 1024 Slate 2 95 w It 825115 4096 Butler 19 95 HIGH Use Intersil 7205 Chip 3341 Filo 695 . 6 EACH 15 MINUTE . 825123 3268 Tr state 3 95 de sae ate 741.0670 494 Repslel 6a IrrStIMI 1 95 QUALITY C -15 CASSETTES . Plated thru double -sided 74186 512 511 Open Collector 9 95 WART'S . PLASTIC CASE INCLUDED P.C. Board 74188 256 TR Open Collector 3 95 9.9.5.1013 30. BAUD 5 95 745287 1524 Slatic 2 95 12 CASSETTE CAPACITY LED display (red) . ADDITIONAL CASSETTES . Times to 59 min. 59.59 sec. with 1,114.5 The Sinclair PDM35. AVAILABLE NC -15 -52.50 ea auto reset \P Quartz crystal controlled A personal digifl . __ `, CAS -6 . Three stopwatches in one: muhimeter for only S 59 5 single event, split (cummulative) $14.95 T.eAwkM .eMUMM and taylor (sequential timing) (Case and 6 Cassenes) O CM1.41eae1 . Uses 3 penlite batteries w nae ImSloldroa' AreureqW naGna 1. daa tl rwn, . Size: 4.5" x 2.15" x 90" News,, g con afford to own. d,eilal Now Io.M,1,nPn nTe,4nn SUP 'R' MOD II multtm le ACakkal411,-4111M kaue I5lulddY UHF Channel 33 TV Interface Unit Kit .A.,w., w.as.iA 1 D. : ,a,m. JE900 $39.95 11. N111, lyrYltal!,-.n.pt,J. , *Wide Band B/W or Color System 1Kethw n,1K,nI. e.1leaJ a,nlnn.. pCCwwMSe..s01 KanFe I Mm2 wmA * Converts TV to Video Display for , i P,,,1. ai . A Jipla^ .J 6. ativl LIP."a '5 Sta,10 I l,u 4aed,91 0.11 n1 hRt,tenlo,n w Pv,v , ! Tli!S1u.lan myM, -i. wlr.lpde Nun 1a.,e."wmnolM' home computers, CCTV canera, 4-Digit Clock Kit 51.1,1y l'UMa<.11n g. 111,1 Ii ow no .,l1n ,1J.1 makeYramdeiJl Apple II. works with Cromeco Daz- n xwuru.nlSmogul Ow mn.ln,n. and 1.rn e1y -am ala. i wr Range , i,.mNili zler, SOL -20, IRS -130. Challenger, on a Apral nmtrm ei ar rLCu r aih ,nF,nr wt human, n,R.R_ F. 1:a_ ,,. ma,kaeJ in mgN hot trh, P..k< we . iaha+ , U. and cIr imnrc hnhln r. aw111 ,.m,nm,:..iwla,n.,e,'eae. etc MOD II is pretuned to Channel 33 wkkle: e : ne (UHF). XMAS SPECIAL - Get your PDM -35 P.ee9pl A e nane,. or * Includes coaxial cable and antenna AC PLUS the 117 volt Adapter and Sx.: hlalrJarJ arm foe transforme. . Bright .357- ht. red display reWienrLF. Padded carrying case for only . Sequential flashing colon dnhb..r 11eÁ.. padded MOD Il $29.95 Kit . 12 or 24 hour operation (Retail value$73.85) $64.50 . Extruded aluminum case (black) PKPRECISION 3'h-OIOII Portable OMM 100 MHz Custom Cables & Jumpers . Pressure switches for hours, minutes and hold modes Oybt05d P,oHClel 3 05h 8 -Digit . Includes all components, case and wall transformer LED ospay =0= Baton or AC °wale. 20 Ha100 MHO Range . Size: 3 -1/411 o 1 -3/4" x 1.1/4" Auto /e,mnq Counter 6-LE0 Display . Four power souces Oma Iva 01 ohm reaololui CrySlalconl'oled Pme9ase banelies. 110 or 2709 with Ovnange read., JE730 $14.95 Fully Aulonulk charger 12V with auto DB 25 Series Cables meg input impendence 111111 10 Palate - comp9le1y bghler adapter and enemy Part No. Cable Length Connectors Pride a Accuacy 1. lypca Ot'I cunu,n.0 7 2.109 purer supply 0825P -4 -P 4 FI 2-DP25P $15.95 ea. R.N.: DC Vertage 0.1000V Sut -175- r 7 Sr MAX-100 4 Ft 1.OP25Pn -255 6 -Digit AC Village 0.1000V 5 63 $134.95 DB25P -4 -S 516.95 ea Fred Response 50 400 HI DB25S -4 -S 4 ft 2 -DP25S S17 95 ea Sc AC LI MOI 0.100mA Dip Jumpers Clock 455154nó 0.10 meg ohm DJ14-1 ft. 1 14 Pin S1 59 ea 99 a Out 64 ít44 192 OJ16-1 It 1 -16 Pin 1 79 ea Accnlorlee: 79 Kit Model 2800 DJ24-1 h. 1 -24 Pin 2 ea ACCESSORIES FOR MAX 100: AC Adapter BC -211 69.00 DJ14-1-14 fl Pin 2.79 ea $99.95 Molala C4reer EWmSWtor 2 -14 . Bright .300 ht. common cathode display Rechargeable ft 19 C.eelwith HlI use Power 115001F banery Model loo - CIA $3.95 DJ16-1-16 2 -16 Pin 3 ea Battselee BP -26 20.00 . Uses MM5314 clock chip 1 Vpw4,1aiing Ma1 CMear/Dlminator DJ24-1-16 ft. 2-24 Pin 4 95 ea ,1 (Watt aua Case LC -211 V AC Mad.1 100 CAI $9.95 Switches for hours, minutes and hold functions Carrylno 7.50 use 110 - For Custom Cables A Jumpen, See JAMECO 1979 Catalog Ion Pricing . Hours easy viewable to 20 feet Simulated walnut case 6 Digit 50MHz Frequency Counter r . ß.g. Mini -Max 3 CONNECTORS . 115 VAC operation Guaranteed Irequency range of 100 Hz to 50 MHz 25 Pin -D Subminiature . 12 or 24 hour operation Full 6 digit display with antiglare window

- - Fully automatic -range. polanty, slope. logger. input level swdNltng not required . Includes all components. case and wall transformer ^ V O825Plas pictured) PLUG S2 95 -- - Lead -zero blanking -All zeros to the Ielt of the first non -zero digit are blanked 600 Hertz . Size: 6 -3/4' x 3 -1/8" x 1.3/4' and Mega Hem dedmal points automatically light up when the unit Is turned on. 0825S SOCKET 3 50

1 - -- Built in Input overvoltage protection. DB51226 -1 Cable Cover for DB25 P or S 75 JE701 $19.95 Use 9V Banery or 110/2200 power. ComPfete with mini antenna Lightweight - Only Boz. MINI -MAX $89.95 63 -Key Unencoded Keyboard Jumbo Accessories For Mini -Max 6 Part No. Description Price 6 -Digit MM-A4 Antenna S395 MM-c5 Carrying case 5 95 MM-IPc Input cable win dip leads 3 95 Clock MM-AC2 110V adapter 9 95 MM -AC3 220V adapter 9 95 This is a 63 -key, terminal keyboard newly manufactured by a Kit $5.00 Minimum Order - U.S. Funds Only Spec Sheets - 25e large computer manufacturer. it Is unencoded with SPST keys, Residents Add 1979 Available 41 C unattached to any kind DI PC board. A very solid molded 13 . Four .630" ht. and two .300" ht. common anode displays California - 6% Sales Tax Catalog -Send stamp plastic x 4' base suds most application. IN STOCK $Y9,95 . Uses MM5314 clock chip /each . Switches for hours, minutes and hold functions PHONE . Hours easily viewable to 30 feet ORDERS Hexadecimal . Simulated walnut case ameco WELCOME Unencoded . 115 VAC operation ELECTRONICS (415) 592 -8097 . 12 or 24 hour operation . autea rJJxno.o w rra... Keypad . Includes all components, case and wall transformer MAIL ORDER ELECTRONICS - WORLDWIDE 19 -key pad includes 1 -10 keys, . Size: 6 -3/4" x 3 -1/8" x 1 -3/4' 1021 HOWARD AVENUE, SAN CARLOS, CA 94070 ABCDEF and 2 optional keysand a JE747 $29.95 Advertised Prices Good Thru December shift key. $10.95/each

Circle 200 on inquiry card. BYTE December 1978 227 Thick Film Crystal Clock Oscillator What's New?

Get Your Feet Wet with a Solderless Breadboard Without Wringing Your Wallet Dry derless bus strips, four 5 way binding posts, a metal ground base plate, non - marring feet and all required hardware. When complete, its 630 tie points permit r flexible configurations of as many as six 14 pin dual -in -line package integrated circuits. Of the four binding posts, one is grounded to the ground base plate permitting high distributed capacitance and LOCO II is a thick film crystal clock low distributed inductance for enhanced oscillator in dual -in -line (DIP) package high speed circuit operation. The three form. Six discrete frequencies are avail- remaining 5 way binding posts can be able: 19.6608 MHz, 18.432 MHz, and used to interconnect the circuit on the 16.000 MHz. PB -6 to power and signal lines and the This miniature oscillator is .820 by outside world. Kit is priced at $15.95 .520 by .250 inches (2.08 by 132 by The PB -6 Pronto -Board Kit comes from Continental Specialties Corp, 70 .64 cm), operates from 5 VDC and complete with a preassembled bread- Fulton Ter, New Haven CT 06509. drives 10 TTL gates. boarding socket, two preassembled sol- Circle 545 on inquiry card. The LOCO II provides master clock frequencies that can be divided to discrete universal asynchronous receiver Compucruise Reduces Fuel and Repair Expenses transmitter (UART) frequencies for various data transmission rates, or they tures, inside, outside or coolant. Its can be divided to provide multiple out- fuel management system indicates aver- puts which can drive combinations of age fuel consumption, fuel used and transmission rate generators, micro- remaining, plus distance and time to processors and LSI circuits in the same empty. The precision quartz crystal computer system. time computer features time, elapsed The LOCO II is priced below $5. For time, trip time, stopwatch and alarm. further information, contact Motorola The trip computer displays distance, Component Products, 2553 N Edington, time and fuel to arrival. A total of 44 Franklin Park IL 60131. functions can be commanded by the Circle 549 on inquiry card. touch of a button. Compucruise features cruise control that will accelerate your vehicle to any preselected road Attention Builders: Cases to House Prototype Electronic Circuits speed, can be instructed to adjust to traffic flow and has a resume feature. Either metric or English units can be Compucruise is an automotive micro- displayed. With a command module no computer combining a 20 button back- larger than a hand held calculator, lighted keyboard, 5 digit blue fluores- Compucruise can be flush or bracket cent display, and appropriate sensors to mounted, and complete hardware and provide a fuel management system, trip installation instructions are included. computer, clock and digitally displayed The price is $189.95 from Zemco Inc, cruise control. Compucruise monitors 1136 Saranap Av, Walnut Creek CA speed, distance, fuel flow, time, battery 94595. voltage and choice of three tempera- Circle 546on inquiry card.

Master System Clock for LSI -11 Low Cost Erasable Read Only Memory Eraser A master system clock for use with Digital Equipment Corporation (DEC) The Information Central E -PROM LSI -11, LSI -11/2, and PDP -11/03 com- Eraser is a 2 part unit consisting of a These Design Mate cases are designed puter families has been announced by 2537 A ultraviolet lamp and a base that to house prototype electronic circuits. Nortek Inc, 2432 NW Johnson St, holds up to two erasable read only mem- They are made of high impact one -piece Portland OR 97210. The dual width ories. It operates from 115 VAC. The insulated plastic and feature a slope module combines the features of a price is $45; Illinois residents should front panel, a metal bottom and include KW-11L real time clock, a KW-11P add 5% state tax. For more information mounting screws. programmable clock, and adds an contact Information Central Inc, 5521 There are two models of the Design

RT -11 compatible date and time N Broadway, Chicago I L 60640. Mate case: the DMC -1 measures 6.75 by clock. Circle 547 on inquiry card. 7.5 inches (16.15 by 19.05 cm) with a An independently powered micro- height that slopes from 1.5 to 3.25 processor helps insure that date, time inches (3.81 to 8.26 cm); the DMC -2 and programmable count are maintained be used as an external event counter. measures 5.63 by 6.0 inches (14.30 by when the processor is not running. The basic unit with standard power 15.24 cm) with a height that slopes Simple operating system modifications supply and installation instructions is from 1.5 to 3 inches (3.81 to 7.62 cm). eliminate the need for manually setting priced at $600. An optional battery The DMC -1 is $6.95 and the DMC -2 these values on power up. backup power supply is available to is $5.95. For further information contact 13 programmable time rates from provide protection against power failures Continental Specialties Corp, 70 Fulton

1 MHz to once per hour are available. for up to 24 hours. Ter, New Haven CT 06509. The programmable clock may also Circle 548 on inquiry card. Circle 550 on inquiry card.

77R n..n.6..10711 nRVTFVw..,.,..i... BUY FROM THE BIGGEST NCE/CompuMart 1250 North Main Street, Department KBC8 P.O. Box 8610 Ann Arbor, Michigan 48107

PET with 81( user V.Oeo Butler - add a THE PET memory $795.00 conventional monitor $19.95 Second Cassette drwe CONNECTION $99.95 BETS( - PET to S-100 I O RS -232 Printer Adapter Motherboard assembled board KH $105.00 $98.50 Assembled With power supply Case 6 $160.00 óB25 $169.00 EXPANDAPET - Economical 6K mop expansion for the PET Ism Beeper PET - contr oiled dudes I daughter board) $43500 beep $19.95 without daughter board $395.00

Hams! Add a NEW ASCII INTERFACES PET to your rig. READER /PUNCH for Reader /Punch 8 LEVEL PAPER MC lOo r M 65 Nam Interlace r TAPE READER and inhcluded software You simply 0..Z Boards 6 Caeles p.ug the unit into PET and Oí $22C your RS232 Serial ready to display tunsmii SJO annd receive ether CW or RTTY at Board Cades Power Suppr airs 100 up In WPM parallel 1490 ASSEMBLED KITS r USED (97 day Serial Il l SELECTRIC -BASED $175.00 Board Power Sup./ LOW -COST PRINTER warrantY) Cades $ 99.95 TERMINAL FOR PET Do Cu mentabon Paralie, 1515 FOR PET Package $15.00 Sepal Irec S895 Tors is completely remrbisned Teletype ready SECOND CASSETTE We have iMer laced our IC Moll. a KSR 33 terminal to PET Use wahinelEEE aaabusasa anus l+ w PETS interlace Io FOR PET 599 use $895 ih. peiipneui Nom Gom71000ie bÖ ec Onal lO Ideal IO. WOsA 0,04 qwh you the ab.lily Io use oÓ1 I apr Processing sopnCalrons INTRODUCTORY 0kÍ inpw ana one Or uI Pm :mrhies etc Sain once il bought.. PE T 9795 PRICE SORCERER tae lags

Vora IM on boed PAY WE WANT TO BUY gr.e4 ROY PACs 10.60 modes Inc anginal Kin, e.panrlPUle single USED MICROCOMPUTERS Peieenl lA manner ROM Cruel Cn l'0 sea Parel'O ssamlaed Any Quantity Operators Renard Top we.u.rnour cale log simply add Now a 5th Generation $179 a monitor and lape decks lo corn. wit Pone, in Terminals: Urgently needed: Immoralal Later ROM PACs will otter loPPIS209 2480 Assembly Language APL PILOT. Word Processing and a DOS EXPAND YOUR KIM SYSTEM Peripherals PAC for disk.based FORTRAN and COBOL What a system for 9895 Introductory Sale Price - .[6051 Manufacturers surplus Sorcerer BK 5695 KIM to 100 Board Immediate Delivery S Sorcerer 161( 91150 Kit S125 Sorcerer 32k 91395 Closed stores stock 161( E.pan n 5299 Assemble° 5169 24 x 80 display RS -232C interface Connector set 115 VIDEO TERMINAL 110 to 9600 Baud KIMA 1119 12'r CRT Monitor E.pansron board lóLno óac,'rd.splay 126pr.ntabk Remote screen control characters software MICRO TECH POWER SUPPLY UNIT [ASCII CASH 3 sensi iMerlaces Uses 8048 microprocessor Assembled 5319: RIte 1 0 true composte railed State -of- the -art design KIM ENCLOSURE oIimpati0ie ieyward,upun TTL AVAILABLE easy pope? n Cire roui KIM a tenre,Y0 0 ance NO alterations required Mu r A full capability terminal completely Kyde. 1CO Black Call Today: (313) 994 -3200 23.50 Aslemmeda tested NOW 5187 assembled with a 90 day warranty for less than you'd pay for a kit. TC -71 SELECTRIC TERMINALS TopOualrly punting terminal Deane leratim with 65.232 PIT ccode in. ;ena+ +KW.EwY eludes de. 130 r une 23' Rani. 'N.aen ASCU 6802 I tan's me It tier Ira 1111 COmpucd - rrrn for cod conversionion y rara a dean rein catalog for delaIS / I

ASCII 9695 - soar based .1+R0 Besuldu1120 129 color ` gr.phk Refurbished 9695 _.. 41( Graphics RAM 9395 \- s, maim 16K ROM Disk BASIC ` CRIamwnp in Ills \ peals 5 en pee Model 3 4K RAM S1495 Acoustic Copley irlsre mint soppy 6593 le Mel al n1' Buktiln 51k n,, 50 10 Unes n ne Model 4 166 RAM 91795 NY ration pre Interlace ASCII FOR TC timi[ p 15232 INTERFACE -71 10r rein alele Ye Model 5 32K RAM lea SYM -1 $2395 Full Ilse keyboard .113413 . sous $179 Preprogrammed drake ....all ESYN.11.10 0000110 COatier 1, 5 A5CIi IC' $159 From Synertek 5269.00 Rockwell New Acoustic Coupler PIKE-VERTER Autocomputer S PAN 5159 59.95 NCEiCompumrl Inc. breaks the AI now 300 M65 prit. barrl.r. with baud The nugmalwOedloRF c Folly raged. and ipi 98.232C acoustic coupler. For only Co n, any a, ambled. ant ha. goodTVntna 91s1) eel an tested ACen551$ IX 65k NAM on $ You u.mUld. mon .iidrl. Wee III PROGRAMMER SANYO lend Ion. unit seek,' accept. the board) Slender telephone bndset for Ne.rdec,nal at der ralur 1115100., on60110 lull or 1.11 duplaa operation. Com- calculator converter Pavedul 4k ROM DebuaMOnlior PLOTTERDLOTTE R MONITOR piele wRh power supply and cents HI PLOT" sachets 1131 add,I,enI la RAM ICI ROM 06042099 dua , i,n,i i $149 detect IIYfL the unit Is housed in an Reg. 20 Col. ASDI Thermal pruner III 559.95 NOW $53.95 UM. ern em I 11 Inanes adracnve case for desk top us.. I1..vm1n I Rep Ana t / 10115011 hairnet. M red ase P. 5129 fun Om 151 eayl Alpnan 11.115 200 or 100 increments yet mcr. 240 st.1, I3 re Pet small II 01 In. or 410 steps per The AUTOCOMP mounts in or on 20.1 A501 l man2 PORT 10 DAY RETURN PRIVILEGE WOW M 005. EIS R3232C (Sena) darn and SI con YOU' pus1113u003 application Cann lei ITC 2.uY. 61.111. TTL. [Parallel] $l 085 1101 prpvrd.5 LEO readouts of She 1.. 29 pig IN pens 90 day limited warranty tolluwnng 0ming luncuona Inalae- W.V. Conn. Ils out I(IM51 in per- 1-800 laneoul MPG Average Mec Poet 2-100 MSN) Newest, most products Used Distance Traveled asp 131.1 exciting MATROX VIDE Cor- Bon connectors lobby coin. rect Time 1111.610 sonal computing Eery Peer connections 521 RAMS S -100 'AUTOCOMP can be installed on Outstanding values inosi AmencM and Japanese ma. OBIlse, tk ROM Assem91.i 1Isl ALT 2480 2aLN SOCI, - Jul. are ran, asset nose with tenor 0,51.1 5295 All items fully assembled and tested and is NOT me om 9tUSK ROM -256 k $375 1534 ALT 256 756 301 mended rot European . mpun unless otherwise stated. dnplay $355 Send for our catalog for more detailed and credit card orders, except as noted. product information. Michigan residents add 4% sales tax. Foreign orders on prepaid add 100/ additional handling (U.S. funds only). P.O.'s Sorry - NO C.O.D. 's. All prices subject to change Ant say trarle .I' Rai. uve+ accepted from D8.0 rated companies. Toll FREE without notice. Write for giant FREE catalog. phones open from 9:00 AM - 7:00 PM EST. Open In the Ann Arbor area? Retail store open 11:00 AM - accounts invited - call for credit application. All or- 7.00 PM Monday- Friday 10:00 AM - 5:00 PM Satur- ders add 4% shipping 8. handling. Same day shipment days.

Circle 283 on inquiry card. BYTE December 1978 229 Circle 115 on inquiry card. -- Electrolabs PO Box 6721 Stanford, 40 01. 94305 *TI Sockets 1 cent per pin. All low profile solder tail B pin - pin. 415.321.5601 TL 345567 The "Pro" fully encoded ASCII KEYBOARD by Cherry. Auto RE- TLX-+M -- PEAT feature, 5 special function keys. 300mA /5V. (Shown as Hard and Soft Sectoring mounted in The Case', Below) $119.00, 3/99.00, 10+ /89.00 Single and Dual Density Double side configuration as a retrofit at any time. USED SYLVANIA The Dumb Terminal for Smart People 110/220V, 50160Hz 12" MONITORS 80X24 with full 128 char. ASCII UC +LC *Pin for pin compatable with Shugart 800,801, 850,851 Working: $69.95 font with all control characters displayed. 300 -19,200 baud RS232. 2nd font addressable (S0 pin edge connector) Cold Chassis, 25Ibs. from keyboard in you -program -it 2708 for THE FANTASTIC! PRICE BREAKTHROUGH! With P39 (Green) APL, Graphics sets, etc. Plug in monitor $425 EACH MERRY Tube 109 I/O connector, 110VAC and you are ready. MEMOREX FIVE -FIFTY CHRISTMAS INCLUDES: 'The Case', Cherry Kbd. A used Double Sided Retrofit$300 monitor, ESAT 200A, all options except vector addressable cursor and modem. LATEST REVISION: ESAT 200B (BILINGUAL) Bulletproof design and construction. Normally $675.00 What you always Stand Alone Single Board Communicating Terminal wanted your ADM3 to be: 80X24 Standard Format SYSTEM "A" $649.00 10/$599.00 Split Speed 110 to 19,200 Baud Two Fonts, 128 Char. ea. in 2708 EPROM Full Feature Cursor, Page X mit., Scrolling 5V @3A, 8 "X14" Board. Requires only a keyboard and almost any monitor for the best terminal for the money anywhere! Supplied with U &LC ASCII in one font. $329.00 NEW P4 (White) NEW! 32 K, S -100 Universal Static Store. Accepts 2114 RAMs or Tube 99 * 70 ns, 3625 PROMS paging up to 8 Mby. Board only with manual "The Case" Beautiful and sturdy and paging software $69.00. 32 Kby RAM 450 ns $679.00, 250 ns anodized aluminum case in deep black designed to contain the $789.00. We have software application notes for multi -task multi - ESAT 200A, and with a bezel cut out for the Cherry 'Pro' keyboard. user applications utilizing paging feature. (installed as shown above) Choose deep brown, light yellow, or crim- son to accent or color code your installation. The only choice for Shilling and Handling: Surface: $o.4o/Ib. Air: $0;75/Ib., 1.00 minimum hard -use institutional and educational applications. $69.00, 10/ 59.00 Cal. l ax: 6.5% Insurance: 50.50 per $100.00

CHRISTMAS SALE (Dec. only) WAMECO INC. Ìwmcjnc 5% OFF ON ALL KITS AND

FDC -1 FLOPPY CONTROLLER BOARD will drive PCBD ON PREPAID ORDERS ONLY FORMERLY CYBERCOM /SOLID STATE MUSIC. Shugart, pertek, remic 5" & 8" drives up to 8 drives, (charge cards & C.O.D. are not included on this offer) on board PROM with power boot up, will operate (not included). CB -1 8080 Processor Board. 2K of PROM 256 BYTE DC DEC.E & AN. ONLY SPECIAL PCBD ...... $23.95 MIKOS PARTS ASSORTMENT RAM power on /rest Vector Jump Parallel port with WAMECO AND CYBERCOM PCBDS status. Kit 125.95 FPB -1 Front Panel. (Finnally) IMSAI size hex dis- WITH MB -6A Basic 8KX8 ram uses 2102 type rams, S -100 plays. Byte or instruction single step. PCBD special, buss. Kit 450 NSEC $123.95. PCBD.....$24.95 DEC. & JAN. $39.95 MEM -2 with MIKOS #7 16K ram MB -7 16KX8, Static RAM uses Protection, with L2114 450 NSEC $249.95 uP410 MEM -1 8KX8 fully buffered, S -100, uses 2102 type fully buffered KIT $299.95 rams PCBD $24.95 MEM -2 with MIKOS #13 16K ram MB -8A 2708 EROM Board, S -100, 8K8X or 16KX8 OM -12 MOTHER BOARD, 13 slot, terminated, S -100 with L2114 250 NSEC $269.95 kit without PROMS $75.00 board only $34.95 MB -9 4KX8 RAM /PROM Board uses 2112 RAMS or CPU -1 8080A Processor board S -100 with 8 level 82S129 PROM kit without RAMS or PROMS $72.00 MEM -1 with MIKOS #1 450 NSEC 8K vector interrupt PCBD $25.95 RAM $123.95 10 -2 S -100 8 bit parallel /10 port, zh of boards is for RTC -1 Realtime clock board. Two independent in- kludging. Kit PCBD CPU -1 with MIKOS #2 8080A CPU 89.95 $46.00 $25.95 terrupts. Software programmable. PCBD ...... $25.95 10 -4 Two serial I/O ports with full handshaking MEM -1 with MIKOS #3 250 NSEC 8K EPM -1 1702A 4K E rom card PCBD $25.95 20/60 ma current loop: Two parallel I/O ports. RAM 144.95 Kit $130.00 PCBD $25.95 EPM-2 2708/2716 161(/32K OM -12 with MIKOS #4 13 slot mother EPROM CARD PCBD $24.95 board 89.95 VB -1B 64 x 16 video board, upper lower case Greek, composite and parallel video with software, S -100. 0M -9 MOTHER BOARD, Short Version of 0M -12. RTC -1 with MIKOS #5 real time clock 60.95 PCBD Kit $125.00 PCBD $25.95 9 Slots $30.95 VB -1B with MIKOS #6 video board less MEM -2 16K x 8 Fully Buffered 5ltair Compatible Mother Board, 11 x 11 th x Ye ". molex connectors 99.95 2114 Board PCBD Board only $39.95. With 15 connectors...... $94.95 $25.95 EMP -1 with MIKOS #10 4K 1702 less Extended Board full size. Board only $ 8.95 16K RAM BOARD by HWE fully buffered, bank se- EPROMS 49.95 With connector $12.95 lect standard to IEE buss gold fingers, solder mask, EPM -2 with MIKOS N11 16 -32K EPROMS plated thru holes, silk screened PCBD $25.95 less EPROMS 48.95 SP -1 Synthesizer Board S -100 S -100 KLUDGE BOARD by HWE for glass epoxy 9 with MIKOS #12 9 slot mother PCBD $39.95 KIT $135.95 over 2600 plated through holes, 4 regulators with board 67.95 all S -100 functions labeled, gold fingers. 82S23 $1.50 PRIME SUPPORT PCBD .... $29.95 MIKOS 82S123 1.50 8080A $ 9.95 PARTS ASSORTMENTS ARE ALL FACTORY PRIME PARTS. KITS INCLUDE ALL PARTS LISTED AS REQUIRED 82S126 1.95 8212 ...... 3.25 FOR THE COMPLETE KIT LESS PARTS LISTED. ALL SOCKETS 82S129 1.95 8214 INCLUDED. 82S130 3.95 8224 3.49 82S131 3.95 L21111 4 {450 NSEC) 7.25 VISA or MASTERCHARGE Send account number. interbank MMI6330 1.50 L2114 (250 NSEC) 7.99 number, expiration date and sign your order. Approx. postage M5600 1.50 2102ÁL -2 1) will be added. Check or money order will be sent post paid In M5603 1.95 2102AL -4 ..___... 1.30 U.S. If you are not a regular customer, please use charge, M5604 3.95 21L02 (450) 1.25 cashier's check or postal money order. Otherwise there will M5610 1.50 27080 (National). 8.95 419 Portofino Drive be a two -week delay for checks to clear. Calif, residents add iIo 5% tax back 30 day guarantee. We cannot accept re- M5623 1.95 4116 Ram) 14.99 ((Apple pp San Carlos, California 94070 turned IC's that Awe been soldered to. Prices sublect to M5624 3.95 -Please send for IC, Xtstor change without notice. 810 minimum order. aí.50 undo, chars. on orders I..e than 810.00. and Computer parts list.

230 BYTE December 1978 Circle 229 on inquiry card. 1is4 co Pe e o 5-i to- NE

aey' . sYo° mc s 5 s P.upES e\c 1 F 910::16:::::e . ;\8 pn\y ¿élleellest: b jie\0 Ste!ni and.t the 5 eesu Sy 11 d I m ème ßeb èmß\a\a\\o0` ptt ay the xA Daps el°Ka9e of enoh ` p^ Ien9 11 eo9es\l, the 00 m0 'voltmet0lf oN(cussen°Spe t° 15 s\ seap 1\80l\08 5 gill med \0 05' lest" EX 888 a\V tt!\\ p19t8 yteet fyted ith roompe not op"J`S9e 55;:s \ 9 ÑOt\\OOPetoofté ples°ItsuSeat Seó l.Hx6gagó'p a\Jè Oa Ces * a Nt 0 ori9 Ins ses e Doen Id.pof O e e In to "a,14:,::: POJ"es Ja\n9Pcoo Wateß tectfoho lle coa le{estDlellc haye Is a\\en Ff om It me^torlst pme^ " ti^8 illiln9 tto anz catH` f¡e tl ódein,e^ttltilP9bô^'oeU sac°co"On eropti+ó u "e, 5 m K Suneri o mPJ\ a"e,ao° ß site n stfumOPet pst aleo ONS' t,angs. c9"\m' 0 1 ac 9e6 soNjGin 9 `G t" tanges. OP\wns' preVe eegf \OVIeN oJt G\ \0 n\ W co Fl Gn$ 44 CN ' Sote 2pV arg°s' ,nq Y pd the JP x\ \pmvvai \o toJ vp 15 e V \n 0 vlpN e Hold tb \nP JpdstpTVl\b\e t3 2.2; vatàtvoSO 7 '4\14'0".4 JoJsr 1e ' ,nges.onaeñstraPmen oul dent at xS.9C 8¡t`lt ompa tobe, énacKn a° SnaPs °t SO Pti. 5,0 alea JoJ vaca.Y 5J,eeb aY"undotn óew` 9 81netapsl r Kpso9at wa eMNV én ar9eóv oe U Ovo\I,\ooom x \S MN `nc" not á 3 .\oPa rrlt $615* n ónbé 8eoblect 1 X. \ jet`é tn nooK ?I` etv na á óñ st \^P°\tvdgjeeV°.ált+ by ..va. ts ca tne \nP`n eò \ . \ v SS oP s e90belt et NO. a Jss sP"ng nd a,ne ON.N x\ dty 1p 'OP ma otne 0qvo` lootdl \ 2951 PretorK KeeP k r o ÿl50PFmJmPJ; 2.JS0 51pN sf VUtleo" p ,o \pt,\KJN \o2gp b as C,L7. C1ù s° V.. JSIe m5-g- eN lt.iAU me9mPensaópe, 7 10(,114N'4; xma9 tne p

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Kt 3 Vi it r n rotc I 1 IOCCItlO ' 3 LEVEL GOLD WIRE WRAP SOCKETS SALE MS -15 MINISCOPEW. Sockets purchased in multiples of 50 per type may be comb bed o bes price Rc4r5.100 enna 6 Cn.rpm unit LM3A 3dig 1%DC $134.00 1-24 25 -49 50 -99 100 -249 250 -999 1K-5K 15 megahertz th. 158.50 bandwid 8 .41 .38 .35 .31 27 23 LM3.5A 31/2 dig .5 %DC....$ External and Internal trigger. PROBE 1C pin LM40A 4 dig .1% DC $ 209.00 Time bas l microsee. lo 05 Secldly 21 PROBE It with the 14 pin' .39 .38 .36 32 29 27 settings. JS:. purchase LM4A 4 dig .03% DC $ 250.00 I of SCOPE 16 pin' .43 42 .39 .35 32 30 Battery or lins Operation. led the MENTION Or Rechargeable batteries and charger in- Automatic 4 line sync modes this MalA21NE Power consumption < IS watts cluded vcn rcrn_ Otio SO P0. rr moot. a3= 18 pin 63 58 54 47 42 36 Measures Volts, AC Volts, and Ga.w4au Iss DC Ohms mma 2r N14 W TS 0 pounds 20 pin 80 75 70 63 58 53 Current mad $17. 22 pin* .90 .85 80 70 61 57 Automatic polarity, decimal and overload 545. indication MS -215 Dual Trace Version of MS -15 $ 435. 24 pin 90 84 78 .68 63 58 Rechargeable batteries and charger 5 -100 BUS EDGE CONNECTORS S Measures DC Volts, AC Volts, Ohms and 28 pin 1.10 100 90 .84 76 71 Current 40 pin 1.50 1 .40 1.30 1.20 1 04 89 and overload Automatic polarity, decimal All sockets are GOLD 3 level CIOSed enlry End and Slde slaeable 2 level Solder Tail Low

Indication 5100 WWO SO IOOCnt 125x, SIDO 510 Con 125 Gen Peoloe Ten Six kris and Dip Plops avaaabte CALL FOR QUOTATION No zero adjustment and no fullscale ohms 21EVELWIRE Vmu 025 rq porle DIP sotole TAIL adjust un 250%Wed rows GOLD piled vECTOpoEE ma FM S also AC 59 1024 rs,04..d GOLD Mr 40 Batteryoperated - NICad batteries; 0.00 0225 5150 a9 1024 LIQUID CRYSTAL DIGITAL line operation. 5.00 1215 350 CLOCK-CALENDAR Large I ED display for easy reading without 80510 50 100 C44, 125 cm DIP R413 SO 100 Cfni 075,,, For AutO. Horn., Office Interpolation SOLDER 741L on 040 sWar1ew5044 PIERCED SOLDER 5411(0 "Hs same Small in size (2e215415) Sue: 1.9 "H e 2.2 "W x 4" D t GOLD ;0.D 6008 m0e,,eoaa 35 Push button for seconds release for dale. Pane B labor guaranteed 1 year Ciocka mount nywner with either 3M 0041214. $ 3.50 Tin eland option Other Popular Edge Connectors sided or VELCRO. Included 370.0C lp !A.merceae 1116..G 22 44 Con, 156 cm 85443 22 44 Cc, ISO CIrs WHRF 2 MODELS AVAILABLE PIERCED SOLDER EcELES Inns .., GOLD LCD IDI Roman. mum.1 rune On $Sl.cOnIened Purchase any of the LM series GOLD peed r4 71 batteries for wuo Man o.., 59 1024 LCD 102 run on 12 von system and a Os. Meters and buy the LEATHER CASE 6300 127S 02 S0 head LCO 101 erLt0102 for 1C 41 OEM and 04,. meny Mar connCIn, av tLv rn o. n....r.on $34.95..

8803 Plugboards INub mi=' .4TÁm.sy r2 MOTHER BOARD FOR u /km i res 47. SITO eus á.Pn MICRO w.dw. a'> COMPUTERS fiiar:ar,ss um. waW 0 31q.t2>.-' 3677 9 z 4.5' Iwsb LOS 6" L Universal MCCCrrocompuleNprotessor 3682 9.6" 4.5" MdM4.,4aturnYlMl O 4500.10 Irse with S 100 bus Com $10.90 7.71 $10.97 jpi,. n too cmxn2 w ee with veal Slur 5 hardware 5 3 It 3677 -2 6.5" o 4.5" %IRV 3690-12 ra rgp1 x a r,xHCe IO e 1 16 3682.2 6.5" 4.5" dew«.r 3662 x CARD EXTENDER 1 -4 5 -9 10 -24 6.5" 4.5" eivwr.w1 r r,.1 $9.81 $9.74 Card Extender has 100 519.95 sii es 515 96 Hi- Density Dual-In -Line $7.65 .. contacts-50 per side on 125 Gen. Purpose D I P .yt'v0v0110.4Pbpn.nw.-R

PRICE. S16.95 FM -7 PC BOARDJ' C50 With HOLDER 5103582 Rechargeable 115 relit' ea 5inced 1t Batteries AS STANDARD ngnungrwlln preclslonly LOW -PROFILE O SC.5 ur. ' 0 Charger BASE . BASE /1 Ielsd For p.o1 rliec'n+50hO0MSl , With . Unll 315 -S same as 315 rP $215 ïa&pIa Rechargeable hol with It bat ro G 1 Blllerlei Fulues novae BY uonp nie ne v011.5 SC S Preecae, Ine range ei umodate "SIN" Ins F4 { laquent, Mnr. yen.19 10 te 10 60 sax+. ma á ONm m Chaflgl y bawds Id 512 WU' Inr ODH VHF 6 UHF It.uIncy un051 The 0,7u1. Unit PRICE.$1795 $54.95 $ 98 nies n LED 1u0011 1,0onp 7591 asslubn ins FM 1 un ce PRICE ne S 511.95 cabana to a accuracy 0, 0 DM 1!: I SC is Murals glary 4á per lacis une Asa 30 rampa teary STANDARD $49.95 Pan smrwety a p0wor0 rodsod nain cna,per art inducted Omens., eel eau re l 9' \\VISE MEAD PRICE S11.95 A66e\ \ x21 Ws79 D me units may tie&maned s4W12157 M as VACUUM BASE Frequmryün Par is S laoop.wareeee war SPECIAL rat slandaoudn 6 160 HORIZONTAL 11S Late, use $20.00 304 JAW VISE HEAD A PRICE: $12.95 Price s175° SPECIAL I 14CS2 100 for °1401 PRICE:$1295 + . \\66 PRICE: MA1003 16CS2 100 for f16" 516.95 JI) a12y4E1 14 pin C52 10 for r2'

- 16 ale C52 Bier '`,III WIDE OPENING ahem CAR CLOCK O `V_ VISE HEAD loose low cost DIP sockets will accept PANAVISE TILTS, TURNS, AND . w width plugs ROTATES TO ANY POSITION. ---/ ao Bright Green Fluorescent Display Crys- both standard and chips. IT MOLDS YOUR WORE i tal Time Base Assembled. add For usa with chips. the sockets offer IOW lust profila height of only 125" above the board EXACTLY WHERE YOU WANT IT. PRICE:$12.95 switches and 12 VOC. T hase socketa ara end stacxabi -f- PRIORITY OINE ELECTRONICS© 24 PIN DIP PLUGS WITH COVERS o WRAP POST 16723B Roscoe KIv i iulve

tall boards on ims page) Terms VISA. MC. BAC. check. Money Order. C OD . U S Funds Only LA residents add 6% sales tax Mini- T -44 pkg too S 2.24 mum woe, 510.00 Orders less than $75.00 include 10% Shipping and hano,ing excess refunded Just in case T-44 pkg please your phone no coon 1Nm 179 1000 914.00 inc'ude A -11 hand Installing 3/ $1.00 tool S 2.00 Send to. our latestbrOChure phone orders welcome (213) 893 -8202 OEM and Insblul,onal Inquiries invited 40/ 9 44 g.00 8 for 9 416 16K Ram's ". Visit our now r tc loc14116 -80, XPAIT00 -RA for APPLE, TRS 800) 423_5633 Visit new rotcil 213) our loss 893 -8202 BRAND COMPUTER POWER SUPP NEW Output Specifications under continuous current loads 5 Volts et 17 Amps ± 2%, 50 my ripple & noise maximum

S Vohs at 125 Amps x 5 %. 50 my n ODle& noose maelmum 12 Volts .r 3 Amps _ 3%. ISO ma ripple d s Oise Indent-mot, 11t 12 Volts ß 2 75Amps c r. 150 mtopple& noise maelmum o 24 Volts V 3 5 Amps a 5 %. 150 me 'apple & noise maximum o o 5 Volt supply has remote sensing and overvoltage protection o Input I I5CAC or 230 VAC. 46 61 11z, complete .ilh standard 115 VAC 3 rire line card. ONLY '12995* We made a fantastic buy of this great offer and pay 'price includes UPS delivery In the continental US on these BRAND NEW only a traction of a large TeleDynamic power sup- computer manufacturers Perfect for Computer Systems with Discs. plies They are shipped to acquisition cost. Supply is you in the original factory limited. we suggest you Great for a Bench Supply. cartons. Take advantage phone your order In CONTINENTAL SPECIALTIES CORPORATION Logic Probes and Digital Pulsers

G0LOGIC PROBES CSC logic probes are the ultimate tool for breadboard design and testing. These handheld units provide an instant overview of circuit conditions.Simple to use: just clip power leadito circuit's power supply. set logic family switch to TTLIDTL or CMOSIHTL. Touch probe to test node. Trace logic levels and puhesthraughdieital circuits. Even stretch and latch foreasy pulse detection. - Instant recognition of high. low or invalid levels, open circuits and nodes. Sim pie. dual level detector LEDs tell it quickly, rorrectly. HI (Logic "1'1: LO (Logic DIGITAL PULSER MODEL LP-2 "13'1. Also Inrorpa blinking pulse detector. e.g. HI and 1,0 LEDs blink an The ultimate in speed and ease of operation. Simply connect clip leads to 1 l's a or off. tracking "I" or 'V stales at square wave frequencies up to 1.5 MHz. Economy version of Model LP Safer than a voltmeter. More accurate than a positive and negative power, then touch DP probe to circuit node: scope. Input Impedance: 300.000 ohms. Minimum Detectable Pule.: 300 ns. aulnmal.r polarity sensor detects high or loss condition Depress the Pulse LED blinks on for 1/4 second during pulse transition. Choice of three circuits models to meet individual requirements: budget, project and speed of logic or Maximum leput Slgoal IFrequ..cyl: 1.5 MHz Pelee Detector (LEDI: High pushbutton and trigger an opposite polarity pulse into the clreml Fad suits. speed train or single event. Pulse Memory: None. troubleshooting includes injecting signals al key pointa in TTL. DTL. CMOS or CSC Model LP -2 Logic Probe-- Net Each $24.95 other popular circuits. Test with single pulse or 100 pulses per second via built MODEL 12,1 in dual control push button: button selects single shoe or continuous modes. Hand held logic probe provides instant reading of logic levels for TTL DTL. MODEL I, P.3 LED indicator monitors operating modes by flashing once for single pulse or OIL or CMOS. Input Impedance:100.000 ohms. Minimum D bin Pulae:50 High speed logic probe Captures pulse. as shore as IO n. Inpul Impedance: cnnUnuou41, fora pulse train Completely automatic. penal size Iabdield pulse ns Maximum Input Slgeel IFregpeacyl: 10 MHz. Pulse D LEDI: High 500.000 ohms. Minimum Delectable Pule.: 10 ns. Maximum %put Signal IFr.- generator for any family of digital circuits Output. Tm stale. PoisrIty: Pulse speed train or single event. Poise Memory: Pulse or level transition detected queacyl: 50 MHz. Pulse Detector ILEDI: High speed train or single event. sensing auto polarity. Sync sod Source: 100 tord Pulse Trae: 100 pps. LED in- and stored. Pulse Memory:Pulse or level transition detected and stored. dicator: Flashes for single pulst: slays Ill for pulse train. CSC Model I P -1 Logic Probe- Net Each $44.95 CSC Model 13,.3 Lodi. Probe - Net Each &69.95 CSC Model DP-1 Digital Pulser Not Each $74.95 e.w Digital IC Testers and DIP JUMPERS COUNTER FLAT RIBBON CABLE ASSEMBLIES WITH DIP CONNECTORS Available with 14. 16.24 end 40 contacts. Mete with standard IC sockets. Fully assembled and tested. Integral molded -on strain relief. Llne -by -line probeebility. MAX100 PORTABLE FREQUENCY COUNTER MAX 100 is a portable. high precision frequency counter that sets nta 'tan dards in performance and value. In a compact. partahle case. it gives you con

LOGIC MONITOR 1 sinuous readings from 20112 to a guaranteed 100 MHz. with Xdigit accuracy

Fast readings with 1 6 sec. update and 1 sec sampling rate. Precise readings, Trace signals through all types of digital omits. Umt clops over any 1111' IC up derived from a crystalconlrolled lime base with 3 ppm accuracy High to 16 pons. Earls of its 16 content connects to a single bd level detector that sensitivity readings from signals as low as 30 mV, with diode overload proles drives a high intensity. numbered I,Et) readout activated when lhr applied n up to 200 V peaks Input signals over 100 MHz automatically flash the most voltage As a fixed 2 V threshold. Logic "1" turns LED on: lope "0" keeps /. i and to indicate low condition and extend life. LED off. A power seeking gale network automatically locates supply leads and significant Apt. battery battery the entire display flashes al I kilt. ` feeds them to the LM l's infernal circuitry. Saves minutes. even hours in o design. troubleshooting. debugging of equipment. Voltage Threshold: O V SPECIFICATIONS U 2 V. lapel Imperials.: 100.000 ohms. 1 Voltage Range:4 15 V ma.. ac i. any luo or more inputs. Curtest Drain: 200 mA at to V Sin: J" I. s _ w s Frequency Range: 20 I1. to 100 MHz guaranteed: 110 MHz typical 611.1 me: when O 1.75" d. open. Weight: oz.. : I o 1 sec Reeolulion: 1 11z. A count lime base error. Input Ins. CSC Model I,M -1 Logic Monitor -- Complete. peduce: 1 megahm shunted by 56 pF. Coupling: AC. Sloe Wave Seseitivlly:30

&59.95 mV RMS at 50 MHz. I I Time Base Frequency: 3.579545 MHz crystal oscillator o LOGIC MONITOR 2 Stability: s 3 ppm al 25° C. Temperature Stability: Better than 0.2 ppm °C. versatility and in Provides p- .Msian testing:tit types of digital circuits 0.50e C. Max. Aging: 10 ppm year. Display: Eight 0.6" LED digits Lead -Zero The fully Isolated power supply and selectable trigger threshold IIl you march Blanking: Decimal point appears between 601 and 701 digit when input exceeds the precise characteristics of the logic family under test. permitting more ac 1 MHz. Overflow: With signals over 91999.999 Hs. most significant deft handl r: urate measurements. The connector di.plav unit clips over any DIP IC up to \ digit flashes, allowing readings in of 100 MHz. Display Update: 1 /6..ec. 16 MATERIALS pins. The power supply module contains lie precision reference power sup plus I see gate time, Low Battery Indicator: When battery supply falls below ply and logic family selector switch. Operation is .simple. Set the threshold Di( LECIPIC UL recoanred glass hued 6.6 VDC. all digits Rash at I Hz. Power Required: In lernal.0 "AA" cells: ooive.is witch to the proper logic family. Connect back clip lead fo circuit ground. For nal. 110 or 220 VAC ch liminalor. au ton lighter adapter or 7.210 CONTACTS Non co" osve coope,enov 7}0 CMOS circuitry. the red clop is connected to circuit positive or L'a. The clip VIIC external supply. Battery Charging: 1214 hrs. Size: 1.75" h. s 5.63' r. s ChEtt E A abieco,iducic,sae o26AWG module oil then clipped over the IC and the LED display instantly gives the 7 75" d. Weight Leas than 1.5 lbs. with batteries. Itandadr 36 un coated coppeiwIhumylnsula logic slates of all pins. Logic Thresholds: CMOS. 70% of circuit Cce: HT L.. 7.5 on An eade it 9.00ve) lop end bol:om loi sago CSC Model MAX100 Frequency Coulter -Net Each $134.95 V: TTL. 2.4 V: DTL, 1.6 V: RTL. 1.2 V. Maalmum Visible Input Frequency: 30 tea, down Rats al 50% duly cycle. slat: Ted Clip. 4" I. x 2" r. x 1.75" d. when open: - MAXI00 ACCESSORIES A P DIP Jumpers are the low -cost. high Power Module. 6" r. a 5.63' d. a 3" h. max. Total Weight: 20 ors Power Re. quality solution for iumpering within a PC 117 VAC.50160 & 3.95 quired: He.10 W: alsoavallahle far220 VAC. 50.60 Ifz at slight Model 100-CIA - Mobile charger eliminator. Net Each board; interconnecting between PC boards. ly higher price. Model 100C41 -110 VAC charger eliminator. Net Each 9.95 VAC backplanes and motherboards; interlacing In. CSC Model LM -2 Logic Monitor- Complete. Model ISO CA2 -220 ch eliminator. Net Each 9.95 CD 5129.95 Model 100.IPC -Input cable with clip leads Net Each 5.95 put /Output ignals; and more. Model 100LLC- Low loss tenor 14.95 All assemblies use rainbow cable. Stan- Model OW MWA -MInn whop utenna 3.95 dard lengths are 6. 12, 18, 24 and 36 inches. ACE All- for fast, solderless, Model Model MCC -Carry race 9.95 Circuit na. 0.s.i.... 1 SINGLEENDED plug-In circuit building 236 l DIP JUMPERS Evaluator and testing DOUBLE -ENDED DIP JUMPERS T Just plug In any cancaMnte with leads to 032" dla. InIN- eonneef with ire up to 20 ga Assemmeu mead tool No. Lanpth LRpth Length Lsngth em. Contacts e° 12" 24" .w riaY scow, ewe I V 97.06 6 R 924106128 924106 18 R 924106 24 924106 36-R w /4 No Length 1241 1262 13 02 1343 iMa n41 r }t 1116x1 9,16.14/16 Ill VS 1261 Contacts 36 tMiv-i.i Ina 1116x1 .1116.1 9. MM 9241166 n 971116 1211 924116 R 9246 24 P 924116 36.0 924102 36 P 16 14 2111-16 nus 1012 Ialta si 16., ran 6265 1334 1380 1233 pli lnsm" l I224 12 e.4 sl 49/16.2 Z4 91 924126 6 R 9741I6 17 R 924126 168 9I4126 24.0 924126 36-R 92411I ER 111usv^ I irr, Unau I 640.7.1.1 46 11 24 16 1415 1450 14 IS SS 20 9590 1259 M. Ixte 1 tala 2,114 al a a.91.1 SI 95 974177 36 R aha 1641 %e.4 or 16 29M 924136 60 9I413617.8 9924136111.R 924136 24.R 924136.36.8 Iosset 01,4.9n4 40 24 o SALE 1693 1752 18.11 1873 19.88 1400 924137 36 R IC TEST CLIPS 40 © 1671 TC -14 3 in. $4.50 PRIORITY ELECTRONICS TC -16 3 In. $4.75 stock productss TC -16 fits 16723B Roscoe Blvd. Sepulveda, CA 91343 we P e 14 á 16 Sri terms VISA MC. BAC check Money Order COD US Funds Only LA residents add 6 % sales tag Mini- :easier,.Easier n entire Pin Dips. mum order 510 00 Orders less than 575 00 include 10`4 shipping and handlmg. excess relunded Jusl In case the please Include your phone no Good thru 1978 Feste

reto for ;9` +.01 Sand for our latest brochure phone orders welcome (213) 893-8202 OEMMa rid Ins NIUNOnaI inquiries i sExYA0-RANI R 06 APP 1610gS So 306 on inquiry card. V I sit our now retc II oc Circle 296 on inquiry card.

You can get you r Electric Selectric here

GTE /IS Novar Selectric Terminals MODELS AND PRICES: MODEL 5541 (IBM 2741 -Type Terminal, EBCD or Corros. Code) $695 MODEL 5550 (w /built -in cassette drive for offline data storage

or use as memory typewriter, EBCD or Correa. Code). - - $1195 MODEL 5560 (ASCII code w /cassette drive) $1295 I/O TYPEWRITER ONLY SPECIAL: MODEL 725 18M Selectric includes keyboard pickup switches, out -put solenoids, and magnet driver PCB to coordinate input/ output signals. Requires +24V and +5V. MECHANISM ONLY, cleaned and adjusted $375 CASE from terminal, with POWER SUPPLY S 75

A standard IBM model 725 Selectric Typewriter for your own 15" carriage Selectric I or Selectric II) is the heart of this off -lease batch -processing hard-copy I/O terminal. (Thousands were made for Sears and other major companies). Printing speed is 15 characters per second. Data transfer rate between terminal and CPU can be as fast as 280 cps (over 2400 baud) by means of the 350 character line buffer and built -in digital cassette tape drive which stores data from the keyboard as typed or as transmitted from a computer or another terminal. FEATURES:. Available in EBCDic or IBM correspondence code versions with ASCII translation and r I/O driver program in 8080 assembly language Microcomputer hardware interface is 10 wire EIA RS232 connector cable between terminal and standard serial I/O cardelncludes complete documentation: Operator and Service Manuals, schematics, interface instructions for microcomputer and software listing of I/O driver and ASCII translation program Optional Built-in 103 or 202 Modem available Typewriter can be serviced by any IBM technician (solenoids, switches and wires have been attached to the bottom of the typewriter without physical alteration of the factory mechanism). 'See, PERSONAL COMPUTING, September 1978, "Techno Turkey and his Electric Selectric," by Lloyd Prentice and Peter Henry. Reference in this advertisement to PERSONAL COMPUTING or to Messrs Prentice or Henry does not imply their endorsement of PACIFIC OFFICE SYSTEMS or its products.

Full documentation included PLUS interface instructions Call or write for details, quantity prices, catalog, 15 day PACIFIC OFFICE SYSTEMS, INC. where indicated. All equipment is shipped insured FO8 return privilege PLUS 90 day no charge replacement of 2600 El Camino Real, Suite 502 Palo Alto within 14 days after check clears or COC defective parts. All orders shipped from stock. No back Palo Alto, Calif. 94306 order is received. Prices may change without notice. orders, no substitutions. M/C & VISA accepted. 14151 321 -3866

POWER OP AMP .125" x .250" Z80 CPU 250mA output current copobility. Operates on os GOLD Fomoussingle chip uprocessor with all the power low os 3V. Input parameters are programmable for CHARACTERISTICS of the 8080A plus 80 additionol operations. Single system optimizing. Electronic shut down allows ELECTRICAL turn. +5V supply and single phone clock. Directly in- output to float. Packaged in 8 pin mini -dip. ..a.,-,.:'IM" Cavan ...one terfaces with stondord static and dynamic RAMS. LMI 3080N $1.94 a . óm.,..nrVw..ewroti Z80 CPU $20 Specs and applications .60 bur AM, Limn. 4Ar o.l..w Tau. Z80A CPU 128 MECHA.iIALFOR I0.*'II57mm. 16K DYNAMIC RAM BLADE Specs 11 Replace your 4K dynamics for memory expansion. I.en,nr.. IT.t r..a ZBOCTC , T x.,a+.an. . Super buy on this exact replacement for the 4116. atá.3.30..n.I Programmable four channel device That provices uPD416 (200nS) S20, 8/S144.00 I0 5óçpmonsm counting and timing functions for the Z80 CPU. uPD416 (300nS) S18, 8/5128.00 eMeA^TERIA`Lrt -. Z 8OC TC 511.00 lM, rYdmemnouu.. ..,o 21L02 -4 (450nS) CLLea.EnrI rma,.umtu..n,..wt, Z8OACTC $16.00 Special buy from major producer allows super ,is..ao.I n.wInw Specs S1 cAea. pricing on these brand new prime memories) rT.an.t a00100n0t1.1m111VA,,0,1 etrtYT MM2102AN -4L S1.44, 64/S73.60 ®7n wmmlWlm Z80 PIO .rt MriAlOW Notown n Porallel interface controller is o two port TTL com- 6502 u Processor $10.95 EDGEBOARD CONNECTORS patible interface with the CPU. Z8OPIO Coero.Iti 111.00 oul.utnt Z80APIO S16.00 CONNECTION DIAGRAMS Tows Outru.re., meld leads In m.tvllwgIcol TO.3 PACKAGE technology, is introduci, It.' new I,p°..d H!3 Specs SI TOP VIEWI ca.* to and TRI -TEK is proud to offer it 1w Ihe first tin* M ow

Í Any refund. 9usroe...,d r4l.ame eä.:..-:aá::.n.. II TRI-TEK mc. for U.S.n... n.. oge. we! w weer a o ao LIS. nd CANADA A00 6% e....vow wno.lrndertMe.wneew.pNWt. Other counm*dd15% IP cPleaseo .gO1"aeon . 7808 North 27th Avenue 0 ws CO naaesae.a. ore. Phoene., Arizona 85021 .. rooms. n 30 m °leer sew.....nwt .ne nrlub SASE .or cool.. cl.r. a.e Ir-Inno. (were not roneM. tor I .r rol. rlrm..,enee. end e.v.nmerbn. Mnele.. lul.mund peer. .50 I a..p aril Mteor* orden 1120 none 1 eel be Clpm. ra e.r.Rlw n.,ewl Inun be mode .anin .a W. mead 6:30 P.M. mow moborms oein. m... ire,* in.al.* nm.... Telephone 16021 091932. No collet, erli piers. w... srr.r e... I

234 BYTE December 1978 Circle 376 on inquiry card. Incredible! but True Precut wire is Cheaper than cutting your own! Catalog available on request. Fast Reliable Economical WIRE WRAP TOOLS No more cutting & stripping by hand Good, clean, uniform strip Cheaper than using bulk wire t,s PRECUT WIRE BULK WIRE like getting it for o0 100 pcso f3" at$.82 = 31/4C/ft. 50 ft roll at $1.99 = 4C/ft. $28 100 pcs of 6" at $1.06 = 2C/ft. 100 ft. roll at $2.95 = 3C/ft. W ire Kit# 1 at $6.95 = 21/3C/ft. HOBBY WRAP Model BW 630 with # 30 Kynar stripped 1" on each end. Lengths areoverall Colors: Red, Blue, Green,Yellow,Black,Orange,White #1 MEr WIRE KIT Wire packaged in plastic bags. Add 25C /length for tubes. pr ($6.95 Value) $ 34.95 100 500 1000 5000 L 21/2 in. .78 2.40 4.30/K 3 89/K Batteries & Charger $11.00 3 in. .82 2.60 4.71/K 4.22/K WSU 30 Hand Wrap - Unwrap Strip 6.25 31/2 in. .86 2.80 5.12/K 4 55/K Tool 4 in 90 3.00 5 52/K 4 88/K WSU 30M, for Modified Wrap 7.25 4'á in. 94 3.21 5.93/K 5.21/K BT 30 Extra Bit 2.95 5 in. .98 3.42 6.34/K 5 52/K 5'h in. 1.02 3.65 6.75/K 5.86/K 6 in. 1.06 3.85 7.16/K 6.19/K INTERCONNECT 6'h in 1.15 4 05 7.57/K 6 52/K 22" x 6.5" CABLES 7 in. 1.20 4.25 7.98/K 6 85/K SK 10 Ribboncable connectorsforconnecting 7'/2 in. 1.25 4.45 8.39/K 7 18/K $16.50 boards to front panels. or board to board. 8 in. 1.29 4.65 8.80/K 7.53/K SINGLE ENDED DOUBLE ENDED

8'n in. 1.32 4.85 9.21/K 784/K SOLDERLESS 14 pm 16 pm 24 pin 14 pin 16 p,n 24 pin 9 in. 1.36 5.05 9.62/K 8 17 /K 1'7 BREADBOARDS 91/2 in. 1.40 5.25 10.03/K 8.50/K 6 1 24 1 34 2 05 2 24 2 45 3 37

12 133 1 44 2 24 2 10 in. 1.45 5.51 10.44/K 8.83/K INCLUDING 33 2 55 3 97 Over 100 pieces of precut wire 24 1 52 1 65 2 63 2 52 2 76 4 3, 191 Addl in. 10 41 82/K 66 /K in assorted lengths - FREE' .1" 201/ 340 291 317 51..

WIRE KITS WIRE WRAP SOCKETS

1 -9 10.24 25.99 100 -249 250.999 1K -5K

#1 $6.95 #2 $19.95 8 pin' 35 33 31 .29 .25 .23 14pin' 35 33 31 29 28 .27 C C (2.2 /ft.) (1.9 /ft.) 16 pin' 37 35 33 31 30 .29 18 pin ' 60 55 45 43 40 37 250 3" 100 41/2" 250 21/2" 250 5" 20pin 84 78 71 63 59 54 250 31/2" 100 5" 500 3" 100 5,/i 22 pin' 90 85 82 78 70 60 24 pin 91 84 78 68 64 .59 100 4" 100 6" 500 3'/2" 250 6" 25 pin strip 1 25 1.05 95 80 70 65 500 4" 100 61/2" 28pin 95 89 84 80 76 .74 40pin 1 50 1.40 1 30 1.20 1 05 .90 250 41/2" 100 7" Gold 3 -Level Closed Entry Design 1 -250 ft. Roll End 6 Side Stackable All prices include gold 2 -Level Sockets Available #3 $23.95 #4 $42.95 (1.7 C/ft.) (1.5 C /ft.)

500 21/2" 500 41/2" 1000 21/2" 1000 41h" 44 Pin Solder Tail $1.75 $15 /10 EDGE CARD 100 Pin Tail 3" 5" 1000 3" 1000 5" Solder $3.50 $30J10 500 500 100 Pin Wire Wrap $3.50 $30./ 10 500' 31/2" 500 51/2" 1000 31/2" 1000 51/2" CONNECTOR ALL connectors include Gold. 500 4" 500 6" 1000 4" 1000 6" SALE! 100 pin connectors are on IMSAI. spacing. Choose One Color or Assortment

ORDERING INFORMATION Orders underS25and COD's.add52 All others. shIpped Ppd in U S n,aUPS LLJW For Blue Label (Ar) or 1st Class. addS1 e We accept Visa it Mastercharge i-EJ11 I la Most orders shipped same day 135 E. Chestnut St. #5 Monrovia, CA 91016 (213) 357 -5005 Dealer Inquiries Invited

Circle 297 on inquiry card. BYTE December 1978 235 / HEATHKIT TRS -80 Z -80 8080 SOFTWARE DOCUMENTATION WRITER Professionally written software TRS -80 At Heath Company quality documentation is in for the serious user. integral pert of the final product. Since Heath is expanding in the computer products re% MEMORY writers are needed to continue the Heath Subroutines and interactive 16K EXPANSION traditions in the software documentation area. programs from $5 in the fol- KIT $ 79.95 We are seeking applicants with: An enthusiasm for personal computing lowing areas: A desire and ability to communicate DISK DRIVES $ 399.00 software concepts Math Science Approximately four semesters of Finance Astronomy programming experience, including CENTRONICS 779 TRACTOR BASIC, one other high level language Statistics Electronics (preferably PASCAL), and the equivalent Navigation Investments PRINTERS $1179.00 of one semester of assembly language A degree k preferred, but does not have Real Estate Amateur Radio to be in computer science Music Analysis Digital Design TRS -80 & PET SOFTWARE. Heath offers competitive salary with excellent Music Synthesis Utility Functions SEND FOR FREE CATALOG. fringe benefits. challenging opportunity and e pleasant work environment. Performance Guaranteed. Send rewrite and salary requirements Write for free catalog. Or phone collect to: H T. Croon APPARAT, INC. HEATH COMPANY BENCHMARK Benton Harbor, Michigan 49022 6000 E . Evans Ave. Bldg. 2 Sr niumb,ryer COMPUTING SERVICES (616) 982-3201 Denver, CO 80222 An Equal Opportunity Employer M/F P. O. Box 385 -B1 303 -758 -7275 Providence, Utah 84332 i Circle 161 on inquiry card. Circle 31 on inquiry card. Circle 9 on inquiry card.

TRS -80 SOFTWARE RS232C Computer Compatible THE Moving Signboard 9.95 Paper Tape Transmitter /Model 612 File Handling (16K RAM req.) 9.95 " COMPUTER Loan Payment /Amortization 5.95 Prime Numbers 5.95 HARDWARE Buzzword 5.95 Day of the Week 5.95 STORE INC. Hamurabi 5.95 Pollution (16K RAM req.) 5.95 Dealers for: Tic -Tac -Toe 5.95 APPLE II, IMSAI Slot Machine (with graphics) 5.95 VECTOR GRAPHIC Petals Around the Rose 5.95 KIM -I. OAE 20% off on order of three or more Stops and starts on character at all speeds, CYBERNEX. JIM PAK One eac'h of all of the above 49.95 uses manual control or X -on, X -off 90 -260 volt, 50 -60 Hz power. 50 -9600 baud, up With Business Systems to 150 char /sec synchronous or asyn- ALPHA -1 CASSETTE SYSTEM Advanced Amway Distributor chronous; gated internal or external clock, Business System 119.95 RS232C current loop or parallel output, 16 Bits Streamlined Amway Distributor reads 5 -8 level tape, 7 -11 frames per ALPHA MICRO Business System 49.95 character, even or odd parity. Desk top or TECHNICO STARTER SYSTEM Amway SA- 1 /SA -2R Verification rack mount. Program 9.95 Addmaster Corporation Catalog Available

Circle Enterprises 416 J unipero Serra Drive 818 FRANKLIN ST., ALEX.. VA..- P. O. Box 546 San Gabriel, CA 91776 703-548-8085 Groton, CT 06340 (213) 285 -1121 1 DEALER INQUIRIES WELCOMED' Telex 674770 Addmaster SGAB E

Circle 48 on inquiry card. Circle 6 on inquiry card. Circle 71 on inquiry card.

New SA4E Bus Microprocessor Modules -Compatible with all Get your "computer nut" Atwood and 544 modules but feature 16addren lines. TRS-SO OWNERS Onboard address decoding. All bare boardeS22.50, the perfect gift. The 8K RAM Beard 121140 Hi Resolute Video 168451 IIIIIIIIIIIIWIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIBII CPU Board (6502/68021 Color Video 168471 Reel -Time Clock STATISTICAL PACKAGE ON CASSETTE original single board ONLY 58.9511 USER ORIENTED YET MORE 544 Microprocessor Card Price List free SOPHISTICATED THAN STATISTICAL PRO computer (an abacus) 5.44 Microprocessor Card Manual 53.70 GRAMS COSTING 3X AS MUCHI FULL EXPLAN Ohio Scientific Challenger II. Ill Manual 9,00 ATIONS AND TABLES INCLUDED. comes in a display case PET Technical Manual (Our Own) with Schemrtica 11.00 -ANALYSIS OF VARIANCE - 3, 4, 5, or 6 groups! KIM-1 User Manuel 5.95 with "Break Glass in KIM Katalog (Our Own/ free -CORRELATION (also provides N, means, & vars.) - KIM Komputer Enclosure 59.95 -T- TESTS -3 types - each gives r, F, Ns, OFs Emergency" printed on PAL Computer Technical Manual 7.25 Means, & Variances! Technical Book Discount Price List free -ANALYSIS OF COVARIANCE- 2group design the front. Computer Surplus Items Price List free -MEAN, VARIANCE, STANDARD DEVIATION Universal 16 -bit Memory Brochure free 2 Radio Price EACH PROGRAM RUNS IN 4Kl -Way Lin fm 6500, 6800, and memory IC Price Ust free - SPECIFY LEVEL I OR II Repaire. KIM. SWTP, or PET Repaired for 52.50 Ohio Scientific Spedal IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIJIIIIIIII New Challenger 1P with BASIC in ROM 329.95 Ohio Scientific Price List fm NEW!! THE FOLLOWING PROGRAMS Wanted: 6800 and 6502 Software REQUIRE 16K Laval II- Send $14.95 plus $2.50 Computer Class (Ohio Scientific/ Fri nba DISASSEMBLER - Shows machine code 515. postage and handling to: Wind Generators and Solar Cells Catalog 2.00 BRIDGE GAME -Play bridge/ 515. SPUR SILVER (714/ 627 9366 GAME OF U FE - Dazzling displays 55. Elecbonlc Communications Co VISA Programs d Swami developed on request. P. O. Box 366, Chino, CA 91710 Mastercharg Intelligent Design or Visit Retail Store Calif Residents Add M, M, & S SOFTWARE 13552 Central Avenue 6% Sales Tu 16 MARILYN LANE 2535 Hayward Drive WESTBURY, NEW YORK 11590 NY State residents add 7% sales tax. Santa Clara CA 95051 1Illlllllllllllllllllf

Circle 212 on inquiry card. Circle 181 on inquiry card. Circle 327 on inquiry card. VISIBLE USED FOR CHARACTER MAY BE USED IN IN MAGNETIC ENVIRONMENT OR RECOGNITION FOR A VACUUM, BECAUSE THERE IS NO INFRA RED COMPUTERS WITH UNDER WATER, HIGH VOLTAGE OR EXTERNAL CIRCUITS HIGH ALTITUDE MAGNETIC DEFLECTION

MINATURE SOLID STATE 202 VIDEO CAMERA KIT FEATURING A...100 x 100 BIT SELF SCANNING CHARGED COUPLED DEVICE

THIS UNIQUE UPDATED CAMERA KIT FEATURES THE FAIRCHILD CCD 202C IMAGE SENSOR ADVANTAGES FEATURES IN THE FUTURE Sensitive to infra red WE WILL SUPPLY A as well as visible light COMPUTER VIDEO INTERFACE CARD May be used for IR surveillance All clock voltages operate at 6V with an IR light source reguiring no adjustments Excellent for standard Higher video output signal surveillance work, because We supply the power board, so only of light weight and small size a 5V 1 Amp power source is needed All components mounted on The circuitry has been simplified for parallel 33/4" x61/2" single easier assembly sided boards Two level TTL output is supplied for Total weight under 1 lb. interfacing

We supply all semiconductors, boards, data sheets, $34900 KIT diagrams, resistors and capacitors, and 8MM lens. Add $75.00 to assemble and test Sorry we do not supply the case, batteries and 5V supply. Add $2.00 Postage and Handling

Wave UNIVERSAL 4KxBMEMORYBOARD KIT PRINTED CIRCUIT BOARD TRANSISTOR SPECIALS ull Bridges DIP SOCKETS 256233-NPN SWITCHING POW ER S 1 95 l'Hv 2A 6A 75A S69.95 B PIN IT 24 PIN .35 a CB RF NPN S 70 100 L3ó .. MRF-8004 Transistor PIN 16 . PIN .20 372102 -1 bully buffered. address lines. on ..,01. 1 I,, la 28 ,40 2:47117 IVPN Si TU 3 S 1.00 200 .75 1.25 2.00 board decoding for any 4 of 64 pages. standard S 60 ,; 5'02 GO 16 PIN ,22 40 PIN .60 2N1546 PIMP GETO3 S .75 400 .95 1.00 4.00 44 pin buss, may be used with F8 & KIM WSP S. 1 1.75 4.00 PIN .25 7 WATTLD -65 LASER DIODE IR $8.95 7540(18 O 3 S I UU 600 1.20 le 256056 71+N S. TO 3 S I 70 EXPANDABLE F8 CPU BOARD KIT 7N3670P111 $ 45 7N5086PNPS.7092 4 S 100 AUDIO POWER AMPS 7N N FI 1 S 1', SANKEN S99.00 545/ 2N3137 NPN Si RE S .05 46 UJ 5.101-0G101'Á175 S 7.80 7....,...1 Fa .,bug PSU 1 K of stale ran. RS 232 2526T S 45 1020 , 11 015 70 ER 11 4 7N]919NPN5,103RI 5 1 50 Si 20 0175 .nieil Ce. I bo CUrnenl al.on. 64 BYTE ipies.er JIKI 7HIG(,I DI'IHF_, SI hl. G IS $7850 214 bll'R Pi101, 1'J7 7N1420 NPN Si TO 5 3/5 1.00 Si 1050 50WÁ7 2N3761NPNSrTO66 5 /0 C /MOS (DIODE CLAMPED) MINIATURE MULTI-TURN TRIM POTS TANTULUM CAPACITORS 4001 16 752222 NPN S. t0 18 5 S 100 4019 37 4049 35 74C73- 65 100, 1K. 51C. 100K, 2K, 10K, 20K. 50K. NPN S. TO S .50 4002 18 4020 90 4050 35 74074 _ 757055 ] 2217F 35V 5SIOf) 60UI .:5`. 4S100 15' 200K, 500K, 1 Meg, 2Meq, S.75 each 3/02.00 IOUF 4006 95 4021 00 4053 - 10 74000 753904 NPN S. TO97 6/S 1.00 47u1 :5\ 5 SI 00 10v S 25 4007 18 4022 90 4055 1.25 70006 40 CHARGED COUPLE DEVICES 7N]906 PNP S. 10 92 6/S 1.00 68111 450 5S100 22UF 25V 5 40 4009 37 4023 18 4066 - .70 74093 .75 755290 PIN Si To 220 5 50 lUl .15V 5 SI 00 15UF 35V 3/61.00 4010 37 4024 75 4071 16 74C151 1.40 CO3 201C 1000100 Imago Sensor 895.00 2146103 PNP S, TO 720 S 55 7 711I 7065 SI 00 313UI 66 5/51.00 CCD 202C 5 S 1 4011 18 4025 18 4076 97 74C160 I OS 100.100 Image Sensor ... 0145.00 :'0.1610 I/.1 ;, I.,'. 011 33UI 20V 4SI00 4/Uf 20V S .35 4012 18 4027 4420 0 MPSA 13 NPN S. 4'S 1.00 37 14C161 I 05 VERIPAX PC BOARD 54.00 4 7UF 15V 5'51 00 68 UF 15V S 50 4013 29 4028 80 74000 .22 74C174 105 This hoard is a 1/16-single sided Paper SPOSO 74151- 61 100 UF 10V S 40 4014 75 4029 95 74002 .22 74C175 1.05 board. (DRILLED and which TTL IC SERIES 74153- 61 45 "085" ETCHED 7445- .65 741.5 SERIES IINEOAR CIRCUITS 4015 75 4030 33 7401. 24 740193 1.20 will hold up to 21 single 14 Pin IC's Or 8,18 or LOI 7400- .13 7446- 68 74154- 94 58 4016 29 4035 97 74C06 22 74C901 48 DIP IC's with bussa[ 101 OOwar supply connector 7401- .13 7447- 58 74155- i43p114 75 55 017 90 4o42 65 74010 27 740902 48 7402 - '3 7448- 68 74157- sr.307 - 30 FP IW P1:;1- Sit Iit..'S 7403- 13 7450- 15 74181- 55 306 75 018 90 4046 135 74042 85 74C914 1.10 t0.60 14 -10 4 RED. YELLOW. GREEN or AMBER 7404- 15 7472- 25 74182 .79 4 ]11 79 LARGE LED3.2" .. 641.00 7405- 13 7473- .28 74183- 55 431e 120 74164- 85 TI L -118 OPTOISOLATOR ... .75 7406 - 18 7474- .28 4 374 .70 7407 - 20 74165- 95 roses u MOLEX PINS 100 SI 00 7475- 45 Ls. 1 M 7408 18 74170- 168 1000 S8 00 - 7476- 30 4350 70 7409 - IB 31 74173- 120 oti.100 TAO s, S IS 5760 /107141K 17,4 1060, 7480- 1370 I 1 7410 - 13 7483- 74171- .95 01 :su.r. 1 .65 4 311 160 :.ii::n WATT ZENERS 33.47.56.91,10, 85 7411- 18 7485- B7 74175- 4300 05 12.15. 18.oe 22V 6 /S1.00 74176- 75 rVatr.cewH ri 112511. 7412- 13 7486- 28 4301 125 MC6860 MODEM CHIP 59.95 7413 - 36 7489 1.25 74177- 75 4347 173 MCM 6571A 7 if 9 characlr, 00,11 010 75 7414- BO 1490- 42 74180- 65 1416r 125 s vs 4,0 7416- 22 7491- 58 74181- 190 .....137 250 7417- 25 7492- 43 74190- I 00 71 sHP L4$52 250 7420- 13 7493- 43 74191- 100 L433! M aCOM Silicon Power Rectifiers 7425- 7494- 67 74192- 79 W 656 66 7428- 7495- 74193- 79 249A 22 65 NILS. 140.001 463101 275 7427- 18 7496- 65 74194- 80 560 -700 1 /0 100 06 14 30 80 500 7430 - 13 74107- .28 H111, !M M 200 0/ 20 35 1 15 4 at 6 50 7432- 72 )4121- .29 74196- 86 566 110 7437- 21 74122- .38 74279- 55 I 10 400 09 75 50 1 40 G 511 9 50 567 RIBBON CABLE 7438. 21 74123.. A5 74367- 50 90 GO') 11 30 /0 180 8 511 12.50 III 721., CRYSTALS S3.45ca. 7440 - 13 74125- 40 75375 I SO 1361] I 0. Coo M,1r .AT (COLOR COOED' p5uu #30 WIRE 800 15 35 '10 7313 1I7511 10.50 7441- .70 74126- .40 75491 50 +971 )447- 37 74150- .94 75492- 50 ;:= n 4i5rI .. 7091 25 0 /Per 1001 1 10 75 17 Goon M,1, 26 cond. 1000 20 45 T 50 2000 35 40 d. . /Pe 1 1 MI Ì RLUICCSN 1024 sta 9eanaaS"7h.cFe1 1/2 HR S 95 75 50 cona. - .911 /ner TOOT SAD 1074 IIA TA CASSETTES e,a.r' 54,11 remsler 518 9S 22 P.n SnhL, Ta .I .156 Co,.,. $1.95 4 1310 250 CTS 206.8 eight Pos tuns dq+sw,tch . 51.50 ,.is,i7 l'. 4148 .Ig914 1456 - M C15 206 4 1tnP PONhOn ng1 switCh ..S1,45 51 50 MM 5387AA new click chop which will directly P,. .ri l900 AO U;I11 ACTIVAII1) 5114 s RS232 OB 25P ,,,al. an 25 do !VP LED's 12174 Ins , I soIply & ai.Pn $5.95 9010CC 390 700V l:, S 70 DB 255 I..m41e $2 95 '"''4 ' 1,18 CONNECTORS 791 1 95 1101105 $1 tIII 120 SILICON SOLAR CELLS NO 30 WIRE WRAP WIRE SINGLE 1r356n 25" diameter AV al 500 ma 100' 51.40 54.00 REGULATORS STRAND TRIACS SCR'S ALM NRNIAOUHE TOGGLE SWIICHtS Fro 359 C.0 .4" 5.50 LED READOUTS 309K S 95 340K 12,15 PRV IA l0A 756 5A GA 35A 106 S .95 Fos 8024 4 meit DL-704 C.A..3" S ./5 723 S 50 I., 24V S 95 MIA SPOT 100 400 70 1 70 41.1 50 1 70 DP 1 70 C C 8" impia'. S5 95 DL 747 C A 6" SI ' LM 376 S 60 340' 5. 6. 8. 17 MIA 206 DT S 700 7U 1 10 175 GO 70 1 60 Fein 503 C C 5'S 85 END 803C C 8" SI 95 3201 12, 15 15.18 or 24V3 95 MTA 2061.OPDT CENTER OFF S 1,85 Fei0510CA 5 "0 85 FNDBIOCA 8"SI95 u, 24V Sl 25 78 MG MSO 206 P -OPDT CENTER OFF 000 1 10 I GO 7 60 100 1 20 270 S1.35 LEVER SWITCH s 1.85 01. 704 3" C C S B5 1 70 3 79 MG . S1.35

7enrlr FOB embddge, Maas Send 254 for our catalog Ieaiuring SOLID STATE SALES WE SHIP OVER 95% Sand Check or Money Order. Transistors and Rectifiers OF OUR ORDERS THE Include Postage, Minimum P.O. BOX 746 145 Hampshire St.. Cambridge. Mass. DAY WE RECEIVE THEM Order 15.00. C 'S $20.00 4S) SOMERVILLE, MASS. 02143 TEL 16171 547-7053

Circle 340 on Inquiry card. BY IL December 1978 237 SURPLUS ELECTRONICS COMPUTER MART LIMITED OFFER THIS MONTH, WHILE SUPPLY LASTS! of NEW HAMPSHIRE, Inc. ASCII 1111 ASCII ge SPECIALIZING IN BUSINESS ge ALL NEW! AND PERSONAL COMPUTERS Mini Discs $3.70 ea. in boxes of 10 North Star Check Balancing Pro - gram $50.00 Two -tier walnut formica enclosure IBM SELECTRIC DATA GENERAL microNOVAI BASED I/O TERMINAL for S. A. 400 Shugart $39.95 XITAN GENERAL WITH ASCII CONVERSION .9- Horizon -2 INSTALLED $645.00 APPLE II R Centronic 779 Tape Drives Cable S -100 Bus Products C Hazeltine 1500 Cassette Drives Wire SOFTWARE currently available: Li Hazeltine 1400 Power Supplies 12V15A, 12V25A, 5V35A Others, Displays AR, GL, AP, Inv., Payroll, A, B & C. A, B & D. Cabinets XFMRS Heat Word Processing, and Dental $4,150 $3,852 Sinks Printers Components Office Manager. Many other items We also stock Imsai, Seals, Okidata, Write for free catalog ADM -3A, Xitan and Cromemco. WORLDWIDE ELECT. INC. n170 Main Street Mail order only. 130 NORTHEASTERN BLVD. NASHUA, N.H. 03060 Nashua, NH 03060 TORA SYSTEM Phone orders accepted using VISA 603/883 -2386 or MC. Toll Free 1- 800 -258 -1036 29 -02 23rd Avenue

In N.H. 603.8897661 croNOVA. e a registered Astoria, NY 11105 i r, adema,k of Data Generat Corp (212) 932 -3533 Circle 395 on inquiry card. Circle 76 on inquiry card. Circle 346 on inquiry card.

CATCHAPULSE II LOGIC PROBL CIT'S SPECIALS ` 10 Nsec pulse response OF THE Open circuit detection

rReplaceable tip 6 cord MONTH oce 5.gh input impedance 4e v s Ce`' r. Pulse stretching Floppy Kit SA 801 floppy (8'1 8 disk cont. 10 Nsec SPEED AT 4 te ßtÿ Mulb tamile kit (S -100) $599 ONLY Add On Floppy Drives 1511 LEVELS 9s SA 800/1 (8 ") floppy $469 $44 SA 400 mini floppy $285 Compatible with DTI., TTL. CMOS. MOS. and Mich). Centronics 779 printer $999 a *k processors using a V to ISV power supply. Thresholds` TERMINAL SYSTEMS INC Miscellaneous automatically programmed .far mullilogic family opera - CP /M Operating System/Manuals... $89 lion. Automatic resetting memory for single or multi-pulse Send S44.95 11300 Harland Street detection. No adjustment required. Visual indication of 8" Memorex Diskettes N Hollywood, CA 91605 logic levels. using LEDs to show high, low, bad level or lhill'nr au (IBM comp.) $3.50 open circuit logic and pulses. Highly sophisticated, shirt (213) 769-6772 8" Verbatim Diskettes pociet portable (protective cap over tip and removable S : 00r. (IBM comp) $3.99 coiled cord). Eliminates need for heavy test equipment. (714) 738.4444 4" Diskettes $3.39 A definite in time and money for engineer and plus (415) 16k RAM technician 573-7723 chips $9.75 'Calif residents add (800) 423.2449 Pwr Supplycabinel (mini floppy)... $79 6,, sales tall to Pwr Supply cabinet (floppy) $225 ELECTRONICS CGMPUER INTERFACE TECHNOLOGY Peripheral Bo\ 19299. San Dicl:u CA 92119 (714) 447-1770 2080 South Grand. Grand Centre. Sente A ne, CA 92705

Circle 23 on inquiry card. Circle 377 on inquiry card. Circle 74 on inquiry card. i Datapoint CRT Terminals EPROM PROGRAMMER THE ORIGINAL -' ,. ®'fit \ - - n LANCASTER 4. Fully- Assembled - * PASCAL* Software available for F -8, 6800, 8080, ¡Guaranteed 8085, 2 -80, 6502, K1M -1, 1802. #3360 $649.50 "Imported from England" The EP2A79 will program the 2704. 2708. Add $15 packing refurbished Guaranteed Strpment FOB. no waiting TMS 2708. 2758. 2716- TMS 2516. TMS 2716. For your micro -NOVA ®, NOVA® Add S35 for scrolling mod, or do It yourself TMS 2532, and 2732 PROM type is selected by NOW -Power your KIM-I or other small processor or ECLIPSE® using ADOS or DOS o personality module which plugs into the Iront from these terminals. Up to 2 Amps al 5. 14. 25 volts. Model from of the programmer Power requirements ore 115 3360 speeds 300-4800 Baud. numeric keypad. cursor controls. Edit. Block- Transmit, search For sensationally low prices VAC, 50 60 HZ at 15 watts. It is supplied with a modes. ASCII Keyboard wth codeable optons. $70 binaries 36 -inch ribbon cable (1 4 pin plus) for connecting Green phosphor. 24 82 Ch. Ines. addressable cursor: RS -232 ser al Interface: other speeds available $140 binaries & sources to microcomputer Requires 1'1 I/O ports Manual $10. Cable klt $9.95 Dalashare /IBM com- Assembled and tested 5145, Plus $1S-25 for patible version 5649.50. Model 3000 $595.00 each personality module. Specify software. M -33 KSR Teletypes $495 00. Call us for seiviCe on CRTs. mcros. main -Lames. OPTIMAL TECHNOLOGY, INC. Contact Gamma Technology, Inc. TELECOMMUNICATIONS SERVICES CO. 800 Welch Rd., Palo Alto, CA Blue Wood 127, Earlysvllle, Vo. 22936 Box 4117, Alexandria. Vs. 22303 Phone 804- 973 -5482 703-683-4019 / TLX 89 -823 94304

Circle 284 on inquiry card. Circle 373 on inquiry card. Circle 148 on inquiry card. P.O. Box 44 OX Santa Clara, CA 95054 Same day shipment. First line For will call only:(408) 988 -1640 parts only. Factory tested. 2322 Walsh Ave. Guaranteed money back. Qual- ity IC's and other components at factory prices.

INTEGRATED CIRCUITS ELECTRONICS CLOCK MODULE Compreta 1401 done rutty to eon up 4115 tranNorma and tonton. Very Compact .Mn W and 740015 143407.16 170 C04511 94 5212 2 90 01' 11000 7430N .17 LM3401.24 1 10 C04515 252 0211 600 NAI0l24,CE.5/- 015 1 50 74029 .17 1143430 C04516 I 10 6211 2 90 102% 14.1144w. Old 74019 .19 114370 115 C04511 1.02 0224 290 9010100. C or E Sar 11.06 74099 .23 114371 1 50 004520 102 6226 5 35 102P2 irratnnx 2.26 74109 .17 114379 500 C04521 1.51 6251 150 Inabltrnewnw andin 74248 13 1113601 1 CO C04526 79 6253 1000 .mew Ws* 74209 .17 1M301 1 60 C01553 0255 9 25 amena 5 75 e /I1o1W 2.95 74221 1,39 111362 1 60 C0456ú 2 25 0257 19 50 1/21013 oar mwti. .3- 74309 20 1117039 40 C04583 4 50 6259 19 50 74428 50 1117094 .20 C04505 110 COP1802CD 1995 r/.. io.. *play it SS 744511 1AE7231109 .69 .50 0040M2 300 C7P1002D 2500 RESISTORS w wan 5% 74479 60 191133N 11 74000 26 CDP1861 12 95 10 Par 00000 03 1000 pee Op* 012 /4469 69 114741CH 35 74001 33 6820 9.95 25 par Noe 015 350 plan 020 74501 .1/ 1M/41N 25 74C10 26 6850 12 95 100par,w..015 5 pw type 6.75 747/9 .29 11414711/N 12 74C14 2.10 6502 12.50 74759 49 11414011 35 7IC20 26 KE5BOAPOS 74859 .88 1141303N 12 14030 26 IC SOCKETS 56 key ASCII I.StOtn0 Mt 562 50 mDN6 01.50 74099 100 1111334 1.10 14C46 I 95 SoIMi11 Lou Pm415 fer/ 74909 43 1111305 127 74C74 75 PIN I UP RN wP S7 Yd, AKll UnOOrd p 5500 FdN CO 74921 43 1111307 2 CO 14116 1 40 6 .15 22 30 *00.17ná 65 brdo.Na 14 95 74931 43 1611310 2.75 14190 1.15 11 16 14 35 9905 74959 69 1111451 47 14033 1.40 16 20 26 42 9001016 15 741000 .90 1111600 175 74C151 3 CO 16 27 36 .50 QUEST Cosmac Super Elf Computer $106.95 Grain. Drang.. 'roots 7016 70 747070 .29 1911612 ] 50 /40'.60 1 44 20 29 40 57 umbo Red 20 741211 .34 1111609 3.00 74C175 1.35 7 4A eee Compare features before you decide to buy any memory select, monitor select and single step. .1n.a'.e Green. Orange. Yellow .0/41 25 741239 89 1912111 1.75 74C192 165 II In 25 1E On 27 CONN. LED No.MM9 alas S31 25 There is no on 741259 39 L112902 I 50 74C221 2 CO 7 4+1 M on W. 20 other computer. other computer on Large, board displays provide output and op- Noma, rea amer. prep. dear) 741459 69 11139001 60 74C905 3 00 ergo.. the market has all the desirable bene- tional There is a 44 pin today that high and low address. 741509 95 1M3905 1 75 740906 75 BRAE WRAP lEVE13 CU11ML1TAL SPECIAL35EO 4 4110. 741519 69 11439091 .61 74C914 195 en lits ofthe Super Eli torso little money, The Super standard connector for PC cards and a 50 pin PIN PIN Comperenne of breadboard Teo 0p 741549 100 MC14507 50 74C922 5 50 11 25 14 66 N44tl 0 S 455 Fq. CB. 1121 le Ell is a small single board computer that does connector for the Quest Super Expansion Board. 741579 69 9E5401 269 74C923 S So 16 27 26 1,00 195E WRAP Y 741619 87 11E5502 65 6.95 16 57 40 1.2] 0[ 100U nod many big things. It is an excellent computer for Power supply and sockets for all IC's are in- 741629 67 615557 .43 74C926 Pastore 9,5050. $1510 7416311 .07 1E5560 79 74C927 U45T /RFO training and for learning programming with its cluded in the price a detailed 90 instruc- 6 95 OIut1AL 11ERMOME7ER 140 SO plus page 74174N 96 NE5650 1.00 A75.1013 550 got ppeer Genres 70 mm, or marnai it is 741151 90 NE5867 1 50 INTERFACE 075.1014 7.50 machine language and yet easily expanded tion manual. 32-_2 -2304. OnpoMb1 probe 000 741901 1.15 9E5677 1 20 8095 65 3341 695 accuracy Comp 0,01. en with additional memory, Tlny Basic, Accii 741929 Many schools and universities are using the .87 9E5106 5 CO 8096 65 w Pact paM 741941 65 1E5710 5.00 6097 65 PROM Keyboards, video character generation, etc. COMPUTER BOARD KITS Super Elf as a course of study. OEM's use it for 742219 1 55 76105 60 8096 65 1702A 395 74290N 165 76106 60 125 N62523 80 RAM 6aara an 5134.95 The Super Ell includes a ROM monitor for pro- 6109 2.95 training and research and development. 7436511 68 19105 .70 eno 450 1025123 353 MI EPROM an 114.95 7436/11 L0 Board x11 1.50 gram loading, editing and execution with SINGLE 66 78M05 15 6713 3 00 9625126 3.15 board w: connector Remember, other computers only offer Super Elf 74361N .66 75106 1 75 8720 5 50 9625129 3 7S Wender 1250 MI STEP for program debugging which is not in- 75191CN 10 7 5 VA* Inrnxe bord 125.00 features at additional cost or not at all. Compare .50 6723 3 9625131 3 749940 111 /5491LN .55 6124 3 50 N025132 6 /S NA EPROM bord an w o PRDM5 74 50 cluded in others at the same price. With SINGLE 16K RFA1aMatbwel belore you buy. Super Elf Kit $106.95, High 7415008 25 15191cN 89 6725 3 20 9625137 6 75 511ík al 395 CO STEP you can see the microprocessor chip 741150111 25 8726 1.69 2708 1250 W rit lax OM RR 1665.00 -K0 415.00 address option $8.95, Low address option 74150011 25 A N D 001805101 0120 275 DM65n 290 90481r1i Don operating with the unique Ouest address and 7415058 25 B0J68 4.50 0097 8223 59.95. Custom Hardwood Cabinet with drilled 119 290 0ECE41 PRODUCTS data bus displays before, during and 74150811 25 emu 13.95 8196 1 69 111671 22 50 11115965 51094885 Trnar 900 alter 14151011 .25 8701CM 22.00 1716 Intl 41.00 and labelled front panel $24.95. NICad Battery PC board 1 27 executing instructions. Also, CPU mode and in- 74151311 .40 8750C1 13 95 IDS/MEMORY RAM louder Mom. PNonbld0n Backup Kit $4.95. All kits and options also come 14151411 .90 1D130 9.95 21011 3 95 indica- 3ac0. 010e 25 struction cycle are shown on several LED 74152011 7.40 1 completely assembled and tested 25 94305111/0 2102.1 95 11 15 4.50 Er0614 00045.5 6.95 74152211 25 IC111103 950 252014 1 60 MHz for lamps. 2 4.50 S minuet...el 74152111 u IC1)107 1425 NO2 125 o 5011 425 12 Cmal Saw IN Ouestdata. a page monthly software publica- 7415309 .25 101. 4 MID 95 5 Operates 5-18 Vas DC to 5 MHz An RCA 1861 video graphics chip allows you to 74153311 39 CMOS 21016 4 95 10 MIN tionfornfor 1200 ersisavailablebysub- 425 ryrya 25.99011.048 15.66 7415381 30 C031001 Fdr. 50 2111.1 3 111161 connecttoyourownTVwithaninexpensivevideo 390 Volvo IaAril noka 50 scription for $12.00 per year. 7415749 .19 W1000 16 21122 95 20M11 3.90 modulator to do graphics and games. There is a 7415758 .47 MIMI 21 2114 1 50 32 MNa 90 P ora6rlr 10041gk 7415901 .01 C0e002 21 4116 1/.95 32761 511 400 9989486! 0220 *I speaker system included for writing your own 7415938 .51 C04005 110 25136 6 30 .6432 11111 4.50 Modal 10 1/104 1802 CO music or using many music programs already Tiny Basic for ANY System 7415958 SB9 CD400/ 21 2R02.1 1 49 3 5795 MH1 1.20 64.100.1B 5229 74151078 .35 C04150 .21 MM5262 10 2 0100 1011 1.95 Model Cassette $10.00. On ROM Monitor $38.00. KO written. The speaker amplifier may also be used 74151129 .35 c04009 39 11145280 3r5 2 097152 MN1 4 50 0066. 536900 Super Ell 74181139 .35 C04010 39 11145320 995 2.4576 MHz 450 to drive relays for control purposes. owners, 30 %oil. Oblectcode listing or MM5330 74151329 .72 C04011 21 591 3 2761 MN 450 6V 3rlgrmaaS 3 25 paper tape with manual $5.50. 74151369 .35 C04012 .11 P04110.3 4 CO 5068/044 450 12 Voi 300 m1 tran.10rw 1.25 A 24 key HEX keyboard includes 16 HEX keys 74151519 .67 C04013 36 P0/110-1 5r5 5 125 MHz 450 Original ELF Kit Board $14.95. 1267 CT 600ma 3.75 plus load, reset, run, Input, memory protect, 74151559 .67 C04014 .86 P5101L 13.95 5.7113MN 4.50 11V250maw.Mug 295 74151579 .67 C04015 .g6 4200A 9 95 6 5536 1191 453 127 CT 250 ma nuom9 350 74151629 .91 CD4016 36 82575 2 90 1431011 MHz 4.25 247 C1100 rra 395 74151638 .91 C04011 01 911024 1 75 10432MHz 450 1011 l2 amoral Mug 415 Super Expansion Board with Cassette Interlace $89.95 7451748 .95 C04016 .04 000165.5 1 95 221184 MHz 4.50 161111.no 1295 74151901 1.06 CD4019 21 MM571g0 4S0 This is truly an astounding value! This board has simply by calling them up. Improvements and 74052216 195 C01020 101 GIAY3e500.1 9 95 DISKAY LIDS CONNECTORS MAXI CA 270 2.90 711525/6 67 C04021 1,02 1301165/10 9 95 44 on edge 200 been designed to allow you to decide how you revisions are easily done with the monitor, II you 7415367e 19 3.50 110X3 CC .125 39 100pnedDe 450 MAN7574 CÚ1ó7á .7Ì 497gó 10 CO MCA 300 1.00 want it optioned. The Super Expansion Board have the Super Expansion Board and Super 1C00n 0009 01* 4.50 uIIEAII C04024 .75 416 1600 01701 CC 300 125 comes with 4K of low power RAM fully address- Monitor the monitor is up and running at the push CA3045 90 c01025 21 500108RD a1CCC CA3048 67 CD1016 1.51 CIOCKI 88000055 0L77227728 5001990 in a A75.2376 1.95 able anywhere 64K with bulb -in memory pro- of button. [117081 1.60 c04021 36 145309 310 512 50 01741/750 CNC 60e 0115.3600 13.50 51750 CC .600 195 tect and a cassette Interface. Provisions have CA1082 1 90 C04011 79 5115311 3 60 Other on board options include Parallel Input c]3089 295 c04029 102 MM5312 483 74C922 5 50 F20359 CC 357 70 70C923 5.50 CC/CA 1 35 been made for all other options on the same 1M301AN;AM 35 C04030 21 I.11I53t3 1205001507 500 and Output Ports with lull handshake They 360 11001655 1M305H 67 c04035 102 MAIS111 390 695 115501510 CC/CA 800 90 it fits neatly into .BOO board and the hardwood cabinet allow easy connection of an ASCII keyboard to the 1.1430711 35 c04010 1.02 54M5315 400 013300/07 call 220 alongside the Super Elf. The board includes slots LM30aN .69 C04041 .71 MM5316 500 ICT.M Was 3 da4 61040 60 input port. RS 232 and 20 ma Current Loop for 1143090 115 c04013 63 11045718 360 1 15 4 091 0 ,694 .60 Ru0rnlmr 1.75 for up to 6K of EPROM (2708, 2758, 2716 or 11 Li/1309K .95 001044 .63 11115369 2 10 054 55 .47 DGB teletype or other device are on board and if you 1 75 1M0111VN .90 C04046 16/ MM5641 M 15 Black 55 47 D010 Floore80016 is 14 pas 0 CO 2716) and fully socketed ($12.00 value). need more memory there are two S -100 slots for LM317T/I1 2.92 C04049 36 04045465 / 95 5 don 110048 14.50 1151469 9 117/1 11.0117 60 1M310 1 35 C04050 .36 cT7001 5 80 Kap 6043 EPROM can be used for the monitor and Tiny RAM video A Clam 39 static or boards. Godbout BK RAM LM3201t 5 0.20 504051 113 007002 0.95 Como wisosoTaook. 7520 onoloc010 Basic or other purposes. 504060 142 C77010 0.95 TIL311 Hex 950 board is available lor$127 95. Parallel 1/13 Ports 1M32303 13.15 1M3200.12 t35 C04066 .71 CP015 /25 TIW951510115 COMPUTER GRADE CAPS A IK Super ROM Monitor $19.95 is available as $9.85, RS 232 $4.50, TTY 20 ma I/F $1.95, 1M320K.15 1.35 a14o61 40 54M5375AAN 3 90 161693 10 1600 mid 200v 450 004069 11 50 1M3201.5 1.60 40 MM5375A61 4 90 1M1122A 2000 mid 457 2 50 an on board option in 2708 EPROM which has S -100 $4.50. A pin connector set with ribbon 11A3201.8 1.61 C04070 .q 7205 16 50 292369 30 3200 505 2.50 1.50 C04071 .21 7207 750 20119000 .20 been preprogrammed with a program loader/ cable is available at 512.50 for easy connection 1113207.12 5500 25V 2.50 IM3107.15 1.60 001072 21 7208 15.95 1929010 25 5800 80v 3 CO editor and error checking multi file cassette between the Super Elf and the Super Expansion 11432411 1.15 C04073 .11 7209 4 95 223083 40 1100 407 3.00 1163391 1.55 C04075 21 050026CN 3.75 2N3631 25 6100 500 301 read /write software, (relocatible cassette file) Board. 06340165 1.10 004076 1.75 05005606 3 75 283643 25 7700 50V 250 another exclusive from Ouest. It includes register 111340K.6 1.10 004071 40 MM53104 2 50 293901 10 0000 55V 2.50 The Power Supply for the SA. per Expansion Board LM310N.12 1.10 CD10B1 .11 293806 IB 91DD 65V 100 113400.15 1.10 C01g02 .21 MICS01ROC215O11 293055 69 10000 20V save and readout, video graphics driver with is a 5 amp supply with 'o. 8 18v + 12v 250 '« -5v. LM700K 24 1.00 C04110 .47 1100 1150 294400 25 33V 3513 blinking cursor and block move capability. The Regulated voltages are . 5v R t2v $29.95. 11130378 1.10 c04490 550 6802 14 95 294400 i5 13,'50°0°00 25V 5.00 Super Monitor is written with subroutines allow- 113407.4 1.10 CD4507 1.00 416000/85 Oda 095 2111102 20 55000 25V 500 Deluxe version includes the case at $39.95. 1.143407.12 1.10 C04506 4.25 0085 2700 TIP31 60 82000 15V 6.00 ing users to take advantage of monitor functions LM3407-15 1.10 cD4s10 1.02 250 29 95 TIP33A co 163000 10V 600

Auto Clock Kit $15.95 Digital Temperature Meter Kit Sinclair 3'/u Digit Multimeter Stopwatch Kit $26.95 OC dock 14th 4 -.50" displays. Uses National Indoor and outdoor. Switches back and forth. Batt. /AC oper. 1 mV and .1 NA resolution. Resis- Full six digit battery operated. 2 -5 volts. MA -1012 module with alarm option. Includes Beautiful, 50" LED readouts. Nothing like it tance to 20 meg. 1% accuracy. Small. portable. 3.2768 MHz crystal accuracy. Times to 59 in 1 yr. guarantee. light dimmer, crystaltimebase PC boards. Fully available. Needs no additional parts for com- completelyassem. case. Best min., 59 sec., 99 1/100 sec. Times std., split regulated, comp, instructs. Add $3.95 for beau- plete, full operation. Will measure -100° to value ever! $59.95 and Taylor. 7205 chip, all components minus +200`F, tiful dark gray case. Best value anywhere. tenths of a degree, air or liquid. case. Full instructions. Very accurate. $39.95 Video Modulator Kit $8.95 RCA Cosmac VIP Kit 229.00 Beautiful hardwood case w /bezel $11.75 Convert your TV set into a high quality monitor D Connectors RS232 Video computer with games and graphics. without affecting normal usage. Complete kit 25 Pin Subminiatures NiCad Battery Fixer /Charger Kit with Lull instructions. DB25P 2.95 DE9P 1.50 that won't hold a charge DB25S 3.95 DE9S 1.95 Not a Cheap Clock Kit $14.95 Opens shorted cells and then charges them up. all in one kit w /lull 2.5 MHz Cover 1.50 DA15P 2.10 Includes everything except case. 2 -PC boards. Frequency Counter Kit parts and instructions. $7.25 Complete kit less case RS232 Complete Set 6 50 DA15S 3.10 6 -.50" LED Displays. 5314 clock chip. trans- $37.50 former, all components and full instrucs. Green 30 MHz Frequency Counter Kit Iuu t,umputer ouarus and orange displays also avail. Same kit w /.80" PROM Eraser Complete kit less case $47.75 8K Static RAM Kit $127 00 displays. Red only. $21.95 Ultraviolet. assembled $49.95 Prescaler kit to 350 MHz 19.95 16K Static RAM Kit 265.00 Clock Calendar Kit $23.95 1978 IC Update Master Manual 24K Static RAM Kit 423.00 60 Hz Crystal Time Base Kit RAM Kit 449.00 $4.40 CT7015 direct drive chip displays date and 1978 IC Update Master Manual $24.50. Com- 32K Dynamic Converts digital clocks from AC line frequency to 64K Dynamic RAM Kt 945.00 time on .6" LEDS with AM -PM indicator. plete IC data selector. 2175 pg. Master refer- crystal time base Outstanding accuracy. Krt in- Alarm /doze feature includes buzzer. Complete ence guide. Over 42,000 cross references. 8K /16K Eprom Kit (less PROMS) $89.00 cludes PC board, MM5369, crystal, resistors, with all parts, power supply and instructions, Free update service through 1978. Domestic Video Interlace Kit $139.00 ,capacitors and trimmer. less case. postage $3.50. Foreign $6.00. Motherboard $39. Extender Board $8.99

TERMS: $5.00 min. order U.S. Funds. Calif residents add 6 %lax. FREE: Send for your copy of our NEW 1978 BankAmericard and Master Charge accepted. OUEST CATALOG. Include 28c stamp. Shipping charges will be added on charge cards.

Circle 311 on inquiry card. BYTE December 1978 239 Low Voltage Miniature Soldering Iron What's New?

Compact Microcomputer Boards Edge Connector Features Wire Wrapping Contacts A miniature printed circuit board for Motorola 6800 parts is now available. The single sided board measures 2 by 4 inches (5 by 10 cm) and has circuits etched for the 6802 processor, 6846 read only memory, 6810 programmable memory and 6850 ACIA 10 port. Other addresses (for additional programmable memory) may be enabled by painting the back of the card with photo resistant paint, and etching away The Model Con -1 edge connector is the unused metal cladding. The board a 44 pin connector for single or double alone sells for $15. sided circuit boards 1/16 inch (.16 cm) Also available is a miniature, fully thick. The connector features .025 inch operational single board computer called (.06 cm) square 3 level wire wrapping the Ace, with 1 MHz clock, program- contacts on .156 inch (.40 cm) centers. mable timer, and a 2 K byte read only The contacts are nickel silver over memory monitor. This full scale 6802 beryllium copper, and feature a bifur- system provides for parallel data output cated bellows design that provides con- rates of up to 50 k bps interleaved stant pressure while minimizing contact The Soldercraft Model 6A is a mini- with serial output at rates of up to distortion and stress. The connector ature low voltage production soldering 500 k bps and comes completely assem- body is molded of Underwriters' Labora- iron designed for versatile microcircuit bled and tested with female connector tories and military approved Valox, an and fine instrument work. This soldering for RS -232 and 20 pin 10 power connec- insulating material of dielectric, thermal iron, when powered by a multitap 18 W tor for $99. and chemical characteristics. The Con -1 low voltage transformer, will provide For more information write Lumbert is priced at $3.49 and it can be ob- controlled temperatures of 700° F at Computer Company, 1220 W Alameda tained from OK Machine and Tool Corp, 6 V, 625 ° F at 5.5 V, 555 °Fat 5 V and #104, Tempe AZ 85282. 3455 Conner St, Bronx NY 10475. 480° F at 4.5 V from its 3/32 inch (0.25 cm) tip. The heat is generated Circle 576 on inquiry card. Circle 575on inquiry card. entirely within the tip, which provides maximum efficiency and faster heat recovery. Automotive Computer Provides Driver Controlled Information Center The Model 6A is priced at $6.90 and can be obtained by writing to the Mitchell- Hughes Co, 7534 Atoll Av, N Hollywood CA 91605. Circle 573 on inquiry card.

Wire Wrap J umpers Save Time American Data Cable wire wrap jumper cables provide a means for making temporary or permanent electrical connections between 0.025 inch (0.0635 cm) square terminal posts, such as those commonly used in integrated circuit sockets and printed circuit connectors. Small components such as diodes, resistors, and capacitors can also be temporarily connected using the jumpers. These cables offer an alternative to wire wrap or clip lead connections during the development and testing of electronic equipment. They are fully insulated and can be installed in a few seconds, generally without turning off equipment power. This self- contained driver- operated The main programming keyboard and These wire wrap jumpers are available automotive computer instantly displays memory entry and recall bars are sized in lengths from 4 inches (10.16 cm) to such data as miles to go, vehicle location, and located for easy access. Large 0.3 6 feet (1.82 m) in five colors. Both estimated time of arrival, miles per inch (0.76 cm) high intensity light assortments and color code by length gallon, cost per mile and 19 other emitting diode displays are recessed bulk packs are available. Contact sur- functions. The Prince On -Board Com- and filtered for optimum legibility faces are gold, rated for 3 A continuous. puter, which is 101/2 by 21/2 by VA inches day or night. The jumpers may be stacked up to three (26.67 by 6.35 by 3.18 cm) and weighs Other features of the unit include deep on a standard wire wrap pin. Insu- less than one pound (0.45 kg), is easily a memory scan and audio alarm which lated sleeving helps protect against installed in cars, trucks or vans by is automatically activated one mile shorts. Teflon wire and sleeving are connecting a speed transducer and fuel before reaching a programmed location. available. Contact American Data Cable flow transducer, both supplied with the The unit costs $400. Contact the Inc, 903 San Antonio Rd, Los Altos CA computer. Prince Corp, POB 6, Holland MI 49423. 94022. Function controls are color coded. Circle 574 on inquiry card. Circle 572 on inquiry card.

FP B -1 FRONT PANEL BOARD FDC -1 FLOPPY DISC CONTROLLER

* DIRECT PLUG I N REPLACEMENT * WILL CONTROL MINI OR FULL SIZE FOR I M SA FLOPPY DISCS * HEXADECIMAL READOUTS FOR DATA, * WILL CONTROL UP TO EIGHT FLOPPIES ADDRESSES, AND PORT AS CONFIGURED, WITH SIMPLE MODIFICATION WILL CONTROL UP * USES LOW COST SEVEN SEGMENT TO 64 DISPLAYS USES CPM * CAN SINGLE STEP BY INSTRUCTION * OR BY BYTE

$50 BARE $45 BARE

OTHER WAMECO INC. S -100 PRODUCTS (bare board price)

* QMB -9 Nine Slot Mother Board $35. * EPM -1 4 KBYTE 1702 EPROM Board $30. * QMB -12 Thirteen Slot Mother Board $40. * EPM -2 16 or 32 KBYTE 2708/2716 EPROM Board $30. * MEM -1A 8 KBYTE 2102 Ram Memory Board $30. * RTC -1 RealTime Clock Board $30.

* MEM -2 16 KBYTE 2114 Ram Memory * CPU -1 8080 CPU Board $30. Board $30.

WAMECO DEALERS AND DISTRIBUTORS: DENMARK UNITED STATES . Electronic. Sytem COLORADO PENNSYLVANIA Piezodan Aps. ARIZONA P.O. Box 9641 Bits and Chips Marketline Systems San 95157 Bakkedraget 55 Computer Ware, Inc. Jo.., 718 9th Street 2337 Philmont Ave. 3480 Fredenborg 214 West Southern Phone (408) 226-4064 Greeley Huntington Valley AUS TRIA Phone (303) 356 -7554 Phone (215) 947 -6670 Margreiter Data System Phone 03- 283744 Tempe, 85282 A -1070 Wien GMBH Phone (602) 968 -6312 Hobby World ENGLAND Byte Shop of Colorado Springs Micro- Computer Products Schottenfeld Gass. 11 5716 West Manchester Leenshire Ltd. 1845 N. Circle Drive 116 5. Pugh Street Phone (0222) 96 l5 65 CALIFORNIA Los Angeles, 90045 13 Cithedral View Adares Micro Computer System. Phone (213) 641-4200 Colorado Springs. 80909 State College. 16801 Phone (303) 633 -7075 Phone (814) 238 -7711 CANADA Winchester SOSS 8PR 239 Frances Street Bakersfield. 03308 Stephen Fielding Hollywood Systems The Computer Broker TEXAS Hamilton Logic Systems FRANCE Phone (805) 393 -1326 9100 Sunset Blvd. Euro Shop 12805 W. Stanford Young Electronics Service 62 Robin. Avenue Computer Suite 112 16, Rue Louis Pasteur Advanced Computer Products Hollywood. 90069 Morrison, 80465 P.O. Sox DD Hamilton, Ontario L8H 4144 Phone (303(979 -6441 College Station, 77840 92100 Boulogne 13 l0 "B" East Edinger Phone (213) 271-9726 Par Phone (7131 693 -3462 F. Jackson Electrontcs Co. Santa Ana. 92705 Phone Parts 825 -82 -52 Phone 39b -8813 Computer Technology Box 20. Site 2. RR /3 (714) lade Computer Products 4901 West Ro.ecrans Blvd. 3400 West 64th Ave. WEST VIRGINIA Aamdale, Halifax County GERMANY Denver. 80221 The Computer Corner Scotia B3L 433 Anchor Electronics Hawthorne. 90250 Nova ABC Computer -Shop GMBH 22 Beechurat Ave. Phone d76 -2920 2102 Walsh Ave. Phone (213) 679 -3313 Schellingatr. 33 Santa Clara Mitt Mini Computer Co. Morgantown. 26505 621 5. Broadway Phone (304) 292 -9700 Orthon Computers 3 000 Munchen 40 Phone (408) 246 -3696 I.C.E. House, Inc. Phone 089/282892 P.O. Box 336 Denver, 90209 12411 Stony Plain Road Phones (303) 778 -6230, Edmonton. Alberta T5N SN) Byte Shop Computer Store San Bernardino Phone (403) 488 -2921 JAPAN 3400 El Camino Real Phone (7141 888 -3690 733 -8681 Onward Enterprise Corp. Santa Clara HAWAII Robo -T ronics Suehirorocho Heim Bldg, Rm 706 Phone (408) 249 -4221 Miko Mattalo Microsy.te ms Limited 419 509 16 Avenue NW 5-5. 3- Chome, Sokokanda, Portofino Avenue 355 Royal Hawaiian Ave. Calgary T2VROJ6 Chiyoda -Ku Tokyo, 101 Byte Shop of Palo Alto San Carlos, 94070 Honolulu Phone (403) 282-9468 Phone (03) 255 -9885 2233 El Camino Real Phone (808) 922-2152 Palo Alto, 94306 PCE Electronics The Computer Shop SCOTLAND Phone (415) 327_8080 4782 Dewey Drive NEW JERSEY 3515 18th Street S. V. AIRAMCO Ltd. Fair Oaks, 95628 William Electronics Supply " DISTRIBUTOR Calgary T2T 4T9 30. Witches Linn, Ardrossan Computrend Phone (916) 966 -7033 1863 Woodbridge Avenue Ayrshire, KÁ22 -8BR Box 2541 -K Edison. 08817 Phone 0294 -65530 Anaheim, 92804 Proko Electronics Phone (201) 985 -3700 Phone (714) 533-3572 San Luis Obisbo, 93401 Phone (805) 544-5441 MINNESOTA Dealer Inquiries Invited ! D. C. I. Computer Systems P.S. Inc. 4670 N. El Capitan 1425 First Avenue North Fresno Moorhead. 56560 University Discounts Available Phone (209) 266-9566 Phone (218) 233.6682 /W777Z,, inc. WAMECO Inc. 3107 LANEV I EW DRIVE , SAN JOSE, CALIF. 95132

Circle 388 on inquiry card. 111 TL Drambér 1979 241 r ASSEMBLY BASIC COMPUTER PROGRAMMERS SHOP Our clients seek experienced mini/ NOW OPEN IN micro assembly programmers and II OHIO SCIENTIFIC software/firmware engineers for a AKRON variety of positions in process con- * COMPUTERS trol. mini diagnostics, terminal sys- Freeway tems, scientific instrumentation and Easy access from telecommunications. Higher level anywhere in Northeastern Ohio SALES & SERVICE fluency or hardware ability a plus. Many systems on display with salaries 14 -35K. Business /Home /Hobby Starting applications software up and We invite inquiries from computer opera ting. Hardware& Software professionals seriously interested in SEE 0.5.1. MOW! advancing their career. We can con. OPEN MONDAY duct your Job search on a continuous. - - confidential basis. For more informa- THROUGH SATURDAY METRO 0 . AREA & MARYLAND tion call collect. Dave Adams at (617) 11 AM till 7 PM The Math Box,Inc. 246.2815. NEW ENGLAND RECRUITERS The Basic Computer Shop ( 301) 277-6828 6 Park. Lakeside Office 2671 W. Market Street Wakefield. MA 01880 CENTRAL VIRGINIA AREA Fairlawn Plaza Fee Paid Management Consultants H/B Computers,Inc. I. Member Mass. Professional Placement Akron, Ohio 44313 Consultants (216) 867.0808 (804)295-1975

Circle 282 on inquiry card. Circle 28 on inquiry card. Circle 213 on inquiry card.

CONVERT ANY TV CANADIANS TO A HIGH QUALITY MONITOR MICRO- VERTER SPECIAL COLOR MODULATOR FOR APPLE II USERS!!

Announcing UHFu Version. Operates above channel I. Eliminares worms'

NEW Operates above the switching harmonica of the computer, nice. UvAL 11 HAMILTON LOGIC thereby yielding a cleaner. wormroee pmfuie. Tunable over a minimum of I channels. Interfaces directly with T TT TI v v V V the Apple II as well as most omer micros. Comet wllh Y V SYSTEMS video cable and OF output stub cou0ler. Two toned cowl Y type decorator cabinet. Sire. 5.5cm 10.5cm 1 11.5 cm.

Power 5V. Current aporro. I ma. Self -powered with I Specializing in logic pence!! banerits. Operating life in mess of 1000 hours MOD -- KITS on near shellhre of batteries. Excellent stability. Precise frequency adrus,ment. Ho assembly required melt, for devices, microprocessors, installation of be cries. not supplied. MODEL MVt500.

AVAILABLE FROM YOUR LOCAL COMPUTER DEALER Hot C hassis or Transformer sets memory s, TTL, Cmos, or direct from ATV RESEARCH. COST including shipping 64 -80 characters per line anywhere in USA and Canada- 535.00. By- passes tuner & I.F. etc. Normal viewing unaffected "PIt EP L E t f R " An IC type videono -RF modulator Safe -Easy installation includes FM sound subcarrier, color subcsrriei and ACVM Hi- Resolution ppd Send for your catalogue separate RV and BV inputs. Designed around Ilse $24.95 LM 1009 chip. A dtugnett dream wills full data than. Model Pt P-4500. KM form. 024.50 postpaid. RFVM Ch2-6 Modulator 7 $9.95 ppd Box "PIt E- VERTER" The original computer video'toRF Pt VAM' ÏNC. Box 29315 STONEY CREEK Interface module. Kit farm: 00.50 Model VIA - PHONE et IVRITf TODAY, DIAL 102.987.3711. s Los Angeles, Calif. 90029 L8G ONTARIO 3X7 1).0 Broadway ATV Reseirch Dakota Clry. Het, Calif. Residents add 6% Sales Tax 1I-ëtJ E8731

Circle 384 on inquiry card. Circle 157 on inquiry card. Circle 22 on inquiry card.

WE SHIP FROM STOCK r TELETYPE MODEL 43 SUPPLIES Only $985 with RS232 $1,085 INTERTUBE: Smart CRT for intelligent shoppers. Call or write for special low price. HOLIDAY SALE ON HAZELTINE TERMINALS FLOPPY DISKS, MINI OR 1500 Kit $885 STANDARD MEMOREX OR 3M Attractive 1500 Assembled 3M DATA CARTRIDGES $995 DC300A, 0C100A Durable Plastic To order: $10 shipping. 24 hr. shipping upon 3M DIGITAL CASSETTES receipt of certified check or money order. Personal 3M DR MEMOREX AUDIO checks: allow 10 days. Credit cards. Add 4 %. N.Y. CASSETTES. C60 DISKETTE CASE residents add tax. 3M DISK CARTRIDGES with each purchase of 10 Diskettes - We Also Export - WE OFFER. at regular price of $3.65 We have no reader inquiry number. COMPETITIVE PRICING Please call or write. IMMEDIATE DELIVERIES DEALER INQUIRIES WELCOME OWENS ASSOCIATES (Any fluent/4/ 147 NORWOOD AVENUE UNCONDITIONAL GUARANTEE V R DATA CORP. STATEN ISLAND. N.Y. 10304 BETA BUSINESS SYSTEMS 777 Henderson Blvd. Day, weekend, evening calls welcome. 8369 VICKERS ST.. NG -6283 448-6298 SAN DIEGO. CA 92111 Folcroft, PA 19032 (212)448 (212) 17141 5654505 = L. Call Collect: 215-583-5101

Circle 34 on inquiry card. Circle 387 on inquiry card. Circle 314 on inquiry card.

2522 BUTLER ST. DALLAS, TEXAS 75235 akin RONDURE COMPANY 214 -630 -4621 1,II computer roots

ASCII SELECTRIC DATEL SELECTRIC (IBM Selectric Mechanism) ¡ Printer Mechanism: Heavy 1 I SPECIAL SALE rrd duty input /output, Series - i¡ $875.00 745. Specifications:

ü;üüi};;((' . j Weight: 120 lbs. Dimen- r Size: 21 "Wx21 "Dx8 "H. Used Working Power I nput 115 Volt sions: 29 "Hx35 "Wx33 "D. - - -1 and Clean Print Speed: (14.8 charac- nferface: RS232 ters per second) -- - Weight: 54 lbs. (Shipping TESTED WITH Platen: 15" wide, pin feed weight 65 lbs.) N EW or form feed device option- 15" Carriage ASCII al (132 print positions). '' -- 15 CPS +' Parallel output only -15 Correspondence code sw1 ELECTRONICS characters per second ac- Half Duplex Factory cepts 7 bit ASCII parallel 132 Print Positions, 10 Reconditioned w /strobe & prints on Selec- "As Is" Complete $395.00 Pitch $1075.00 tric. The Unit still works as Working $495.00 ASCII Selectric with ASCII parallel electronics. a typewriter in off -line Reconditioned $695.00 Immediate Delivery- Shipped from inventory. mode. Used - $395

NOVATION DC3102A ,,,rlrIiirt,,, SHUGART TI 990/4 MINI -FLOPPY DRIVE Used Single Board 16 Bit Micro - - Working V' Computer r: :i ^ -- 1

' ._.... NEW $250.00 . '.7" á ,". ..;: .....i '35 ... 12V! 'rte,- m * NEW PRICE 1 © USED MODEMS &COUPLERS Z $325.00 ea. FLAT PACK ACOUSTICALr $150.00 NOVATION TC102 (Acoustic) $45.00 IMF MODEM PICK -UP AJ 233 (Acoustic) $25.00 Model SA -400 Useable with most modem RS232 Connection CF 318 (Hard Wire) $25.00 chips /kits 300 Baud Used - $17.50 (w /prints) ORDERING INFORMATION: SHIPPING INFORMATION: We ship the same day we receive a certified check or money order. Modems: $2.00 each; 2 tor $4.00 UPS. Texas residents add 5% sales tax. Please call if you have a question. Large Items & Parts: Specify Freight or Air Freight Collect Write for our CATALOG of many parts, terminals, printers, etc. Foreign Orders: Add appropriate freight or postage. All items subject to availability. Your money returned if we are out We now take Master Charge and Visa orders, Specify full number, of stock. bank number and expiration date.

ATTENTION TRS -80 & APPLE USERS IN TIME FOR CHRISTMAS A PRINTER FOR YOUR COMPUTER

$99500 Ready to plug into your computer MODEL 3S -80 for TRS -80 Ready to plug into your expansion interface. Very high quality print

MODEL 3S -PP Completely refurbished for computers with 8 bit serial IBM 731 I/O port. Selectric terminal in a new table MODEL 3S -SS TERMS: VISA, MASTERCHARGE, for computers with RS -232 Cashier Check or Money Order. Upper & lower case C.O.D. with 10% down. port. removable type ball Shipping Via Air or Truck collect. 3 S SALES $109500 for Special I/O interface P.O. BOX 45944 MODEL 3S -AA TULSA, OK 74145 Includes RS -232 card for Apple!! Heavy duty re -mfg. IBM 918/622 -1058 Specify model number on order. power supply

Circle 356 on inquiry card. BYTE December 1978 243 At last...the mechanical interface! LSI-11/2® -tliA 1011-HA® LSI -11/2 Microcomputers TURN YOUR ELECTRIC TYPEWRITER INTO A LOW COST, HIGH QUALITY Quantity Price HARD COPY PRINTER.

1 - 9 $500.00 The all new I/O Pak from Rochester 10 up $460.00 Data, Inc. interfaces the keyboard of any commercially available electric typewriter with any computer. The result: low cost, high quality hard copy. COr.1P000ilFE The eUlldln0 AL3tDmOtlOn lhet Sches best choice Write today for more information. in mainframes ! Distributor inquiries invited. To order, call or write: 0100 CARD FRAME AXIAL BLOWER USER LIST $395.00 F. Ferragonio 14 MHz 12" CRT MONITOR ASSEMBLED& TESTED 18 AMP POWER SUPPLY READY FOR YOUR CARDS Quantity and distributor Compuguard Corporation UPPER & LOWER CASE 0995.00 um ere discounts available. 4709 Baum Boulevard ASC! KEY BOARDS Pittsburgh, Pennsylvania 15213 WEALS° HAVE ROCHESTER DATA, INC. POPULATED SYSTEMS, 0100 CARDS (412) 622 -6200 LARGEST SELECTION OF 1802 SOFTWARE 3100 MONROE AVENUE ROCHESTER, NY 14618 ® Registered trademark of 111M INFINITE INCORPORATED Digital Equipment Corp, May- Cdebrmm3 Our /510 1..:. nard, MA 325 WAVERLY PL., MELBOURNE, FL 32901 - PHONE 13051 724 1588

Circle 171 on inquiry card. Circle 310 on inquiry card. Circle 47 on inquiry card.

Thinking of changing jobs? TRS -80 If you have a degree in SPECIAL engineering, chemistry, PROMOTION SALE physics, SAVE 10%, 15% or more on ALL geology or com- Computers, Peripherals, Software, puter science, The Career and ALL other fine Radio Shack® Advertiser can make you products. aware of the job oppor- couplers NO TAXES on out -of -state ship- tunities you might other- , connect: always ments. wise miss. Nationwide in FREE Surface delivery in U.S. The D otec 30 Originate Only and the WARRANTIES scope - Arranged t o save Datec 32 Originate Answer acoustic couplers will be honored provade reliable Bell System 103 113 compatible by your local Radio Shack' store. your time. Duplex or Half -Duplex. 300 bps doto communication over conventional telephones The Career Advertiser Offered exclusively by Department 4 Datec acoustic couplers ore the only couplers P.O. Box 4067 Fort HIII Station on the market with CRYSTAL CONTROL Radio Shack Lynchburg, VA 24502 for both the receiver and the nonsmitter The Datec 30 and Dotec 32 acoustic Authorized Sales Center couplers connect, lime and time again 1 117 Conway Six months (12 issues) $5.00 Please send payment with order. Mission, Texas 78572 FREE SAMPLE COPYON REQUEST (512) 585 -2766 Your name kept confidential -Notan agency P. O. Box 839 Chope) Hill, North Carolina 27514 phone: (919) 967-5605 CM)

Circle 83 on inquiry card. Circle 85 on inquiry card. Circle 304 on inquiry card.

NOW AVAILABLE ... nAn ` / BLERS r. 0. BOX 1491 GALESBURG.J IL 51401, Compucolor II DISKETTES INTRODUCES - - - THOUGHTWARE! Designed To Make The Operation DI Your VERBATIM for Your DRIVE Perumal Compute Easier And More Fun Persona 1 Color Graphics Computer THE TRS.IB POKE GRAPHICS WORKSHEET Soft Sector E in Supports buck, ease ,phot n machine y !ensues., or .n Iullerí unnraton of Level II &u5345 10 Sector baoxes I PIS or MINI 16 Sector $3 of 10 , 90 at $ 1495.00 2 pals al 25 ,Io n 58 55

THE TR5-80 GRAPHICS WORKSHEET Ea. in Those et smog m continue Me rmplemenunon of tim SET STANDARD boxe s STANDARD FEATURES: 2d 11ESET eaarnends are vMd tu aller. Soft or Hard Sector of 10 a pane al 2.5 53.95 4.10 4 Awls Meets S6 95 13" Color CRT d1 25 for Northstar j Special Graphics Pkg. THE LINE MINGER CP M 1.4 Disk &Horizon 145 Ruler shp suMn you type programs, lmn lollowmg mar. 16K Extended Disk Basic easy a.. Ow LS Mnder.- Set of 1.1.96 L 1.61or. !1/ 8K RAM Memory PLASTIC BOX lorD sakned s s3 OUR VARIABLE MINDER lies The Mildest Uall TAsgl 72 Key Keyboard Ste et vante the dadabndy of all 1762 MINTI s in a. then t e rossumdrms Allows lull mown..W Minidisk Drive t 3B18 mar long.pnua.d Programmera HAZELTINE CRT 1500 alblES1000 ')'yarn of 25 Meets $19s 2 paon of 75 Meets 55.95 Complete 1.23 Computer S AND OUR SELECTION OF NOTE PADS System: Hazeltine 1500 Horizon -2, Centronic 779 SADDLE BROOK Kees, th in t of those s of t thoughts. Passage of 6 pads 1300 een. all sense ní1m l 53.95 Visa, Master Charge, Cash, C.0 -D. STEREO INC. TOUR CHOICE OF TITLES BELOW. DON T WRITE IT OFF Ill Bubble Babble. 121 Elsa . 131 Daddy Nam. WI 203 Market St. TRS HO Owners Co, ewdlm Tmo Anyone. LSI Floor, Cony. MANCHESTER EQUIPMENT CO., Inc. J 161 Podded) Oda. DI Uncle, DMsuwon. 151 ran." say 'ton, Make ASCU OI S e l l Saddle Brook, N.J. 07662 30 Midland Ave. Hicksville, N.Y. 11801 ref more intormairen. acne Phone: (201) 843 -7500 Summer sea...summed Eddie., Call Collect: (516) 4330613 rumors nemeents Ado a J11117

Circle 337 on inquiry card. Circle 174 on inquiry card. Circle 211 on inquiry card. Circle 30 on inquiry card. MEIMEIMMMEIMMEMEIMMI All Prime Quality - New Parts Only I BECKIAN ENTERPRISES Satisfaction Guaranteed IEDGE CARD CONNECTORS: GOLD PLATED. SUBMINIATURE CONNECTORS: (DB 25 SERIES, RS 232.) BODY: Non battle, solvent resistant, high temp, G.E. Valox. The finest you can buy. DB 25P Male Plug $2.50 ea. 5 pcs. ea. CONTACTS: Bifurcated Phos. /Bronze; Gold /Nickel. DB 25S Female Socket 3.60 ea. 5 pcs. ea. DB 512121 Grey Hood 1.20 ea. 5 pcs. ea. IALTAIR S -100: Cont. /Ctrs ..125" Row Spacing, .140" DB 51226 -1A Black Hood 1.30 ea. 5 pcs. 1.20 ea. 50/100 Dip Sold. $3.95 ea. 5 pcs. $3.75 ea. D 20418 -2 Hardware Set 0.75 ea. 5 pcs. 0.70 50/100 Sold. Eye. 6.95 ea. 5 pcs. 6.50 ea. SAVE: BUY A SET: (1 DB25P, 1 DB25S, Any Hood.) 1 Set: $6.35 ea. 5 sets: $6.15 ea. IMSAI S.100: Cont /Ctrs 125" Row Spacing, .250" NOTE: For Hardware, (D20418 -2) Add $.65 /Set. 1 50/100 Dip Sold. $4.20 ea. 5 pcs. $3.95 ea. 150/100 W /Wrap 3 3.75 ea. 5 pcs. 3.50 ea. WHISPER FANS IMSAI CARD GUIDES. 0.19 ea. 5 pcs. 0.16 ea. Excellent for cpmputer cabine; cooling. This is the most quiet fan you will find. Only measures 4 3/4 square by 1% deep. U. L. Listed. CROMEMCO S.100: Cont. /Ctrs..125" Row Spacing, .250' $21.00 ea. 5 pcs. $19.00 ea. 50/100 Dip Sold. $6.50 ea. 5 pcs. $6.00 ea. Or short W /Wrap) I. C. SOCKETS. GOLD. I. C. SOCKETS. WIRE WRAP 3 TURN. OTHER CONNECTORS AVAILABLE Dip Solder. Tin. 14 pin $0.36 ea. 14 pin $0.15 ea. I100" Contact Ctrs., .140" Row Spacing. 16 pin 0.38 ea. 16 pin 0.17 ea. 22/44 Dip Sold. $2.30 ea. 5 pcs. $2.10 ea. 25/50 Sold. Eye. 2.95 ea. 5 pcs. 2.75 ea. 2708 EPROMS PRIME 8080 PRIME I40/80 Sold. Eye. 4.80 ea. 5 pcs. 4.50 ea. $14.00 ea. $9.00 ea. 43/86 Dip Sold. 4.90 ea. 5 pcs. 4.70 ea. 43/86 Sold. Eye. 4.90 ea. 5 pcs. 4.70 ea.

I.156" Contact Ctrs., .140" Row Spacing. 6/ Sgle. Row (PET) $1.00 ea. 5 pcs. $0.90 ea. WRITE FOR LARGER QUANTITY DISCOUNTS. DEALER INQUIRIES ARE 22/44 Sold. Eye. 1.90 ea. 5 pcs. 1 (KIM) .80 ea. WELCOME. I22/44 Dip Sold. (KIM) 1.90 ea. 5 pcs. 1.80 ea. 43/86 Dip Sold. 4.90 4.70 ea. 5 pcs. ea. WE ARE CONNECTOR (EDGE CARD) SPECIALISTS. IF YOU DO NOT SEE i WHAT YOU NEED IN THIS ADVERTISEMENT, PLEASE WRITE US. WE WILL .156" Contact Ctrs., .200" Row Spacing. REPLY. 15/30 W /Wrap 3 $1 .05 ea. 5 pcs. $0.95 ea. 22/44 W /Wrap 3 2.30 ea. 5 pcs. 2.10 ea. TERMS: Minimum Order 510.00: Add $1.25 for handling and shipping. All orders 36/72 Sold. Eye. 3.45 ea. 5 pcs. 3.30 ea. over $25.00 in USA and Canada: WE PAY THE SHIPPING. ' 36/72 W /Wrap 3 3.85 ea. 5 pcs. 3.70 ea. NOTE: CA residents please add 6% sales tax. 43/86 W /Wrap 3 5.50 ea. 5 pcs, 5.00 ea. NO C.O.D. SHIPMENTS OR ORDERS ACCEPTED. POLARIZING KEYS FOR ALL OF THE ABOVE: MAIL ORDERS TO:Bec/Karl 'Specify: IN Contact or BETWEEN Contact: Enterprises 1 to 49 pcs. $0.10 ea. 50 pcs. /Up $0.08 ea. SPECIAL P.O. Box 3089 12/24 Pin .156" Cont. /Ctrs..200" Row Spacing. TIN PLATED CONTACTS. IDEAL FOR PET INTERFACE & PARALLEL USER PORT. Simi Valley, CA 93063 `ffffffffffS1 .25 ea. 5 pcs. $1.10 ea. i______mil

Discount Prices on

DEC* LSI-1 1 COMPONENTS

Manufactured and tested by Digital Equipment Corporation. Compatible with DEC PDP* -11/03 and Heathkit H -11. Or build your own computer using the card cage assembly. All cards 8.5 x 5 in.

KD11 -HA LSI -11/2 Central Processor Unit. Includes power fail /auto restart, I/O DMA port, real time clock input, vector interrupt handling, firmware debugging and ASCII console routines, List $695 $ 599

MSV 11 -DA 4k x 16 -bit RAM, List $416 $ 350

MSV11 -DB 8k x 16 -bit RAM, List $850 $ 675

MSV11 -DC 16k x 16 -bit RAM, List $1375 $1095

MSV11 -DD 32k x 16 -bit RAM, List $2400 $1925

H9281 -BB 8 -slot card cage and backplane $ 155

Other components available, write MICROPROGRAMMING, INC. for catalog. Quantity discounts. Terms COD or prepaid. 1351 Larc Industrial Blvd. Burnsville, MN 55337 *Trademark of Digital Equipment Corporation Phone: (612) 894 -3510

Circle 221 on inquiry card. BYTE December 1978 245 FOR SALE: SwTPC 40 printer; 40 columns, 75 lines per minute. I've been using it for about one year and it works great!! $200 or best offer. Digital Group Phi -Deck mass storage with two drives, PHIMON, cabinet and cable. Complete documentation included, $400 or best offer. Holden

Caine, 1 Windsor PI, Melville NY 11746, (516) UacIw$IOed Ads 692-9512. FOR SALE: 8 K PET, Commodore. Too small for my needs. Two months old and completely burned in. Some software and additional manuals. Will ship anywhere in USA, $750. Mike Avelis. WANTED: My 4 K PET needs more memory. FREE: Data cable with the sale of a Persci 1070 108 Wynola Av, New Britain CT 06051, (203) Anyone with access to eight MOS 6550 pro intelligent disk controller $500 assembled and 2247016 after 6 PM EST. grammable memories please write Barry Swartz, tested. TDL SMB board (dealer demonstration 3727 Tartan Ln, Houston TX 77025. (713) 663- model). Two serial input /outputs. one parallel WANTED: Z -80 or 8080 system monitor and 6401. cassette interface and TDL 2 K Zapple Monitor 5.100 complete front panel with any available in read only memory and 2 K programmable data. Steven Friedel, 33 -44 149 St, Flushing NY FOR SALE Altair factory assembled 2510 board. memory. Fully assembled and tested, $220. 11354,1212)358-8160. Wired for T.TY and RS232. Never used. Best offer. TDL software package A with 12 K BASIC, Write or call Robert Cardamone, 304 S Penn St, Z-80 assembler, ZTEL, text output processor, FOR SALE: Sphere Boards: processor /2, cathode Punxsutawney PA 15767. (814) 9384185. all to run under CP /M format. 8 inch diskette, ray tube /1A. Best offer. Richard Likwartz, 827 manuals and notebook, $189. Call or write Ted West St, Rock Springs WY 82901, (307) 362-5316. FOR SALE RS 232 interface for Diablo printer Nakamura, 3421 Onyx St, Torrance CA 90503, with CDC interface advertised in May and June (213) 371-8138. FOR SALE: 16 K Level II TRS -80, Diablo 1200 1978 BYTE. $250. H Stone, 64 Morgan Cir, Hy-Type (without keyboards), Regency HR -212, Amherst MA 01002. FOR SALE: Best prices. 5.100 bus 16 by 64 R390 receiver. Will swap 212 for talkie with video interface (ASCII and block graphics), keypad. Karl Schneider, 4423 W Broadway, FOR SALE. Set of BYTE magazines September assembled $100. 8 K programmable memory, Muskogee OK 74401, (918) 683 -6511. 1975, number 1 to July 78, volume 3. number 7 assembled $100. Prototyping board, including (complete. except November 1977, volume 2. buffers and regulator on board $20. Full ASCII FOR SALE: KSR 35 tabletop ASCII teleprinter. number 11) 33 magazines total. Excellent con- keyboard, including user defined keys $35. Call Uses either serial or parallel input /output, $550. dition. Best offer, (614) 3893452. or write Philip Klein, 1524 Sacramento St Four SwTPC 4 K static memory boards, $75 Berkeley CA 94702, 1415) 524-9711. each. Heath 10 101 vectorscope /color bar gener- WANTED: For MBT Inc (model 015) Disk ator, $85. Gary Wachter, POB 18955, San Antonio Memory Unit: specifications, schematics and FOR SALE: HP-67 calculator for sale, program- TX 78218, (512) 655-9314. maintenance manual. This company is now out mable, automemory stack and much more. Un-

of business. I have been unable to obtain tech used, will accept reasonable bid. Call (913) 642- FOR SALE: E & L Instruments MMD-1, As- nical information through normal channels. Bert 4663. sembled and running, with Bugbooks. $250. Jim A Richardson, 13 Fern St, Natick MA 01760. Church, 3570 Cortez Dr, Dallas TX 75220. FOR SALE: MITS Altair 8800A, 8 K program- FOR SALE: Kleinschmidt teletypewriter TT-117/ mable memory, serial input /output and audio FOR SALE: 4 K Dynamic programmable FG with reperforator/transmitter, Baudot code. cassette 10. all documentation, $450. Bright memories, MK4096, MK4027, TMS4060, tinned, Used and working. $100. Tektronix type CA dual 2610 magnetic tape drive, 800 bits per inch, 27.5 speed unknown (coded for Honeywell), $2 and $1 trace plug-in unit for 585 or similar scope, $150. inches per second with two controllers for Data each. Teletypes: 35KSR, 33ASR, $450 each. Two M H Research R1008 plus and minus 300 V DC General line of minicomputers. Tape unit was Digitronics 3500 HS paper tape readers, less power supply. $25. Locarte 3 A 120 V DC power working with one of the controllers when removed electronics, $75 each. Two MFE Digital cassette supply (not isolated from AC line), $20. Lambda from system, condition of other controller un- transports and parts, $90 for lot. 14 pin DIP LT 2095M 0 to 32 V, 0 to 2 A power supply, known. Schematics and manuals included. $850. cables, $1 each. Will consider trades for Shugart $75. SwTPC 143 0 to 35 V, 0 to 2 A power L D Stricklan, 21733 Alcazar, Monta Vista CA Floppy disks for above. Carl D Cole. 1134 E supply, $20. All items plus shipping. S Lei, POB 95014, (408) 257-4805. Geneva Dr, Tempe AZ 85282. 5312, Fargo ND 58102. FOR SALE Dual trace oscilloscope. Heath 10- FOR SALE: DEC PDP -8F Minicomputer system. FOR SALE: BYTE number 1 to date, $25 year. 4510, 15 MHz. with calibrator, manuals. Like 16 K, two disk drives, video terminal, ASR 33 SCELBI BB users manual, machine language, new, $545. Digital Multimeter, Heath IM-2202 and much software. Make offer. John Robinson, assembler, monitor, editor, four issues SCELBI with manual. Like new, $160. Swan 350 Amateur 725 Berry Ln, Lexington KY 40502, 1606) 266- Computer Digest for 8008 and similar computers, Transceiver, with 117cx power supply, transmitter 1509. all for $50. Other manuals and books on control unit VFO, manuals. Good condition, $345. electronics and microcomputers. You pay postage. Robert Shostak, 1961 Camino de los Robles, FOR SALE: Kleinschmit ASCII print drum (76 Davey B Moyers, 10743 Karen Gale Ln, Jackson- Menlo Park CA 94025, (415) 3260443. columns). Electronics /parts for 311.321 printer. ville F L 32225, (904) 641-9485. Best offer takes it. Bill Vaughn, 2415 Richview WANTED: Any information that you may have CI, Garland TX 75040, (214) 495-2371 evenings.

FOR SALE -. Texas Instruments TI -59 program. pertaining to Radio Shack TRS-80 software and

mable calculator and PC-100A printer complete peripherals. I have a 16 K Level II system and WANTED: Software for the VIM-1 on cassette or with extra paper rolls, magnetic cards and pro. would like to add a printer and disk. Both must listings. N Carr. 13709 Peyton Dr. Dallas TX

gramming manuals. All for $300. Peter Ludwig, be capable of running off a 50 cycle power as I am 75240. 921 Fernwood Av, Plainfield NJ 07062, (201) stationed in Athens Greece. Robert Daniel, PSC 263 -0200 text 3576) days or (201) 753.9780 Box 2088, APO, New York NY 09223. BOWLERS NEED HELP: Hardware, software and evenings. information needed to operate a state bowling FOR SALE: Teletype 3320 printer with 5JE tournament. Robert Woods. 220 Madison St,

FOR SALE: Heathkit H-8 Computer System; punch /reader. Carterphone DX 103A -7 and Dal - State College PA 16801, (814) 2383816. expertly assembled and tested. Includes 24 K static Data Dialer: $730 plus shipping. Steven Terharr,

programmable memory, serial and cassette input/ 650 Beech, Moorhead MN 56560, (218) 236-8129. BYTE ISSUES: I have BYTE numbers 1 thru 15, output, H-9 video terminal, cassette player, all except number 11. Best offer takes them. Thomas standard Heathkit software plus Extended BASIC. FOR SALE: Centronics 101, 132 columns, 5 by 7, G McBride, 178 Mitchell. St, West Orange NJ

all documentation. I am graduating from college 165 characters per second, 8 bit parallel interface, 07052.

and must sell; asking $1725 and I will ship it. Carl uses standard size pin feed paper. $950 on trade or write Dan Harrington, 927 J St, # 498, Davis for Diablo Hytype II. Frank Bennett, (408) 732- FOR SALE: Heath HB, H9, 16 K, cassette re- CA 95616, 1916) 756-7932. 3800 ext 633 (work) or (714) 7350549 weekends. corder, assembled and running; $1200. David J Marcus, 430 Wolf Hill Rd, Dix Hills NY 11746,

OSI CASSETTE INTERFACE USERS: I have (516) 427-1926. Ek' U.VCf-4SSlf/ElJ POf./Cl' some modules for 430 board to increase reliability. Also mods for 420C for standby power and modifi- FOR SALE. SwTPC 6800 mainframe; no cards, Readers who have equipment, software or other Items cation of the OSI Audio Cassette Tape Generator just mother board and power supply. Assembled ro buy. sell or swap should send in a clearly typed nonce program to produce double speed tapes. I would and tested. $150. James VanProoyen, Weeks ro that effect. ro be considered for pubbcauon. an artier like to share information on these or similar Co Inc, 1057 Cottage Grove SE, risemenr must be clearly noncommercial. typed double Electric Grand spaced on plain refute paper, contain 75 words or less. and subjects. Phil Bryan, 529 West St. Park City IL Rapids MI 49507. (616) 2438866. Include complete name and address mformauon. 60085. These notices are free of charge and will be printed one FOR SALE: AMI EVK -300 system M6800 1 time only on a space available basis. Nonce, can be ac FOR SALE: TI 59 calculator with all standard card 1 K memory, cepred from individuals or bona fide computer users clubs computer. With programmable only. We can engage in no correspondence on these and accesories and numerous games, in perfect con- 2 K erasable read only memory and programmer, your confirmation of placement is appearance in an issue of dition, asking $220. Also for sale one slightly Prow monitor. Microassembler /Disas read only BYTE used KIM -1, in very good condition with power memory. Four parallel and one serial ports to Please note that it may rake three or fourmonrhs for an supply and all manuals. Philip Kaaret, 1113 E State 19,200 bps, 16 K board for the above, ad to appear ,n the magazine. $700. St. Ithaca NY 14850, (607) 272 -9119. $390. Zvi Peshkess, (517) 355 -3164.

246 December 1978 0 BYTE Publications Inc FOR I SALE: KIM and power supply; complete, FOR SALE: Digital Group 2.80 4 board system MUST SELL. SOL 20 with 24 K programmable working. First $200 takes it and I will ship it. including processor, 10, video terminal cassette memory: Panasonic monitor. cassette; North Star Send SASE for return of late checks. Send cer tit ied and mother board assembled. Also two 8 K controller with Shugart SA400 disk drive; music check or money order to Upchurch, 107-G Judy memory boards with ICs and sockets plus Maxi - interface board: 15 K extended cassette BASIC; Tall Oaks Dr, Greensboro NC 27408. BASIC, Editor, Super /Clock 12 software plus ASCII K disk BASIC: game pack 1 . Everything works - Keyboard and Encoder. Will take best offer. less than six months old. $3400 value for $2995. APPLE I am a Apple soft- OWNERS: collector of Asking $500. Oldrich Laznicka, 24 Payson Rd, J Andrews, 6303 Kury. Houston TX 77008, (713) ware and have over 200 programs for the Apple Belmont MA 02178, or call (6171 484-4978 alter 8693985 evenings. fl. Send me your programs on disk or cassette and 6 PM weekdays or weekends. I will trade them on a one -to -one basis. Dave FOR SALE: 8 K byte, 250 nsec, 5.100, static Garson, 5163 Rd, Rolling Hills Willow Wood WANTED TO BUY: Texas Instrument model memories, $175. IBM Selectric type balls, $10. Estates CA 90274, (213) 378-3623. SR -52 programmable calculator in good condition. IBM Selectric tool kit, $25. IBM Selectric 10 Dale Sebok, 127 Timothy Dr, Tallmadge OH pitch to t2 pitch conversion kit, $35. AC /DC FOR SALE: Digital Group Z-80 system. 34 K: four 44278, (216) 633-4297. power supply, 5 to 9 V, 20 A. overvoltage protect, digital cassette drives (Phidecks); keyboard; overcurrent protect, $80. Sunny power supply, monitor; all software (MaxiBASIC, Business FOR SALE: Digital Group complete Z -80 PhiDeck 9 V 25 A, ± 18 V - 4 A; - 9 V -4 A, $85. Stan BASIC, assembler, Star Trek, chess, etc). Total system with speech synthesizer. Major components Levine. 1802 Melville St, Ocean NJ 07712, (201) price as kit over $3300. Up and running for $3100. include dual PhiDecks, monitor, keyboard, 32 K 531 -8305. John Case, 6703 Timberhill, San Antonio TX static memory, finished cabinet, VOTRAX speech 78238. (512) 681-7504. synthesizer, and substantial software. Assembled FR IEDEN EQUIPMENT: 36 pieces, one alloter, and perfect working order. Best offer over $3000 eight regens, (two brand new -still in crates), two FOR SALE: SwTPC 6800 Computer System; 16 K (price new $37501. John Theys, 24 Walnut Av, card punches, 13 2305 slave printers, one SPD, programmable memory, serial 10, AC30 cassette E Setauket NY 11733, (516) 473 4142. SPD stand, one Computyper with program blocks interface and Smoke Signal Broadcasting 8FDÔ8 and desk, one Selectadata transmitter, three trans- disk system. All documentation and software. FOR SWAP: Will swap BYTE issues May, Novem- mitters, six power supplies, miscellaneous assort. $1400 or best offer. Craig Colvin, 817 Cheyenne ber or December 1977, for September 1976 or ment of cables, spare parts, schematics, paper tape Dr, Walnut Creek CA 94598, (415) 937-0778. January, February or April 1977. Bert Honroe. and edge punch cards. Also three McGraw Edison Schuermanslaan 65. 3070 Kortenberg BELGIUM. Voicewriters. No reasonable offer refused, plus FOR SALE: What am I offered? BYTE magazines, shipping. Ron Komara, PO8 267, Davidsville PA September 1975 to December 1976 in BYTE IBM 3705 BSM: Did anyone ever try to connect 15928, (814) 479-4674. set binder and full of 1977 copies, unbound. All a 3705 -1 Bridge storage module (core). They are perfect condition. Dick Neish, WOSIR, 904 available now as most installed model is get FOR SALE: SOL 20, two SOL 10s, Altair 8800A Marday, Sioux Falls SO 57103. converted to model 3s having FET storage. If with mother board, 24 K bytes of static program. anyone did, please get in touch. I'm having pro- mable memory, 10 board, MITS vector interrupt FOR SALE OR TRADE: BYTE volume 1, # 1 blem in the sense latch. Bert Honroe, Schuermans- board, real time clock board, ICOM dual floppy through # 10. All ten issues, top condition, $75 laan 65, 3070 Kortenberg BELGIUM. disks, ASR 33 Teletype, TDL 2- processor. Send or best offer. Don Erickson, 6059 Essex St, River offers and receive detailed list. Herbie Marsden, side CA 92504, (714) 738.3709 anytime. FOR SALE Heathkit H9 video terminal, and 608 Kelly, Silver City NM 88061, (505) 538- Heathkit H10 paper reader /punch with parallel 5229. WANTED: A Flexowriter with upper and lower board and connector cable. Fully assembled and case characters suitable for computer generated running, checked out by factory. Best offer for FOR SALE: ASR 33 like new, with recent Inte- letters. Working or not. Don Erickson, 6059 Essex both or either. R Nicosia, 234 41st St. Lindenhurst grated Circuit Touch Tone Modem. Includes St, Riverside CA 92504, (714) 738.3709 anytime. NY 11757. all manuals, $750. You ship. Also SwTPC CT1024 with scroll, 16 lines, 64 characters, upper /lower FOR SALE: MOS technology KIM -1 micro- FOR SALE: Two Innovex 200 double density 8 case, custom oak /formica cabinet, and lots of computer, manuals and power supply included, inch disk drives, $200 each. Three Innovex 420 spare parts. $225. Julian E Jetzer, 6400 Hawthorn $150, KIM -3 8 K memory board, manual and double density 8 inch disk drives, $300 each. 4 Rd. Sheboygan WI 53081, (414) 457.3366. power supply included, $100. Martin Goldberger, board Z -80 System (2.80 4BD) largely factory 15 West 72 St, New York NY 10023, (212) 874 assembled with 10 A power supply, $900. CAS & FOR SALE: Poly B8 chassis with two Altair 4 K 3176 evenings after 6 PM and weekends, C82 Phi Deck Drive System (kit) with PHI -F. static memory boards, WAMECO 8080 processor $300. Two blank 8 K memory boards. One 10.4 board, Vector Graphic Reset-n-go programmable

HELP! I was too ambitious. I have 20 M6800 kit. Robert Frieden, 359 Wilson Av, Kent OH and read only memory beard and National Multi- chips in original factory packages. Will sell for $15 44240, (216) 6737181. plex 10 board with 4800 bps digital cassette each or trade all 20 for a minifloppy drive in good deck. All are in excellent working condition. condition. Bill Ganoe, 1634 E Drachman, Tucson FOR SALE Complete set of BYTE from volume Will include nonworking S D Sales Z -80 processor AZ 85719. 1, #1 to December 1977. Perfect condition. Jim board. Sell system for $500 or will sell separately. Larus, 27 Varick Hill Rd, Waban MA 02168. W R Gillen, PO8 781, Richardson TX 75080. GTE DIABLO FOR SALE: Commercial Hytype I printer /keyboard, fully equipped; RS232 interface. FOR SALE- Digital Group TVC.64 board; operates FOR SALE: PDP BL minicomputer with 4 K core

E Grossman, 410 Albany Post Rd, Croton NY fine, with OP-System and documentation. Also and teletype interfaces. I Ehrlich, 284 Hendrix St, 10520. Radio Shack keyboard video terminal added. $175 Philadelphia PA 19116. for both. Bob Howarth Jr, RFD # 1, Box 36, FOR SALE: Complete Poly 88 system with a 41 K Lisbon NH 03585. FOR SALE: Wintek M6800 processor with ASCII programmable memory, 3 K erasable program- keyboard, ACIA, monitor, two PI As, 5 K memory/ mable memory, 8080A processor, 16 by 64 video, SHERLOCK HOLMES FANS: You are invited power supplies, and cassette tape 10. $250 or best graphics, hardware scroll, 300 and 2400 bps to correspond with Ben Fairbank, 307 Kent Av, offer. Bob Watson. 2853 Pebble Beech Dr, cassette, real time clock, serial port, four parallel El Paso Texas 79922 to consider together the Flagstaff AZ 86001, (602) 526.2312. ports, single step hardware, 2708 erasable program. possibility of undertaking various computer mable memory programmer, two DACs, 16 analyses of the "Sherlockian Canon" with the FOR SALE: AKI keyboard, matrix encoded, channel ADC, 9 inch monitor, cassette deck, all eventual goal of producing a concordance to the 60 power supply and 5 level paper tape punch, $50. 5 hardware, documentation, and extensive software stories. level paper tape reader, $50. Ron Rogers, PO8 support. There is one S -100 slot left for a card 17147, Baton Rouge LA 70893. of your own. I will consider any offer over $2200. FOR SALE: Heathkit Computer System includes Michael Dunn, 45 Livingston Rd # 501, Scar- HB computer, H9 video terminal. 16 K memory. FOR SALE: MMD-1 8080-based system for inter- borough, Ontario CANADA M 1E 1K8, (416) 266- 10 board, cassette player, all manuals. schematics. facing experimentation and software development. 1635. Also includes many programs. Completely as- Assembled and tested, $275. Norm Levin, 4408 sembled and tested. Will pay shipping. $1500. T E Sherwood Rd, Philadelphia PA 19131. INFORMATION WANTED: For G E TDM Allen, MAG -11, H$MS-11, W /C620. MCAS Eltoro

114A40 data set: I bought one and I need to test CA 92709. WANTED: Cylindrical slide rule (such as Thatcher

it, repair (if necessary), and use it. I would be or Fuller) and pocket circular slide rule (such as willing to trade printing or programming or pay for FOR SALE Altair 88008 System: full front panel, Carpenter or Sperry) or any other unusual old information. etc. Write Robert Heller, Box 51A 12 K static programmable memory, audio cassette, slide rule. Also need pocket mechanical calculator Star Route, Wendell MA 01379 (nophone). serial 10, Microterm act-1 keyboard with Sanyo (Curta). Describe and price. Dr George Wentz, monitor, cassette recorder, package II assembler PO8 626, San Marcos TX 78666, (512) 392 -2872 FOR SALE OR TRADE: Heathkit Digital Tech- and 8 K BASIC plus many programs. System after 7 PM. niques Course and Trainer, Model 15 Teletype fully operational. Total price: $1850. Additional parts including keyboards, type boxes, mainframes, equipment: Altair parallel 10 88 .4PIO, $75; FOR SALE: Centronics Printer #100: used, $750. and smaller parts. Will trade for Heathkit micro. Cromemco dazzler, $200. Cromemco bytesaver Aaron Epstein, 5437 Laurel Canyon Blvd, Suite

processor trainer. George Kelm, POB 160, Yap with 1 K erasable read only memory, $100. Com- 208. N Hollywood CA 91607, 1213) 7620020. Caroline Is, GUAM 96943. plete documentation. Call Tom, (614) 369.3866 nights. FOR SALE- Ithaca Audio Z-80 board, $35; FOR SALE: Altair 8800 mainframe with processor Percom Data Cl-812 cassette interface, $30; D C board, 1 K programmable memory, 2 K program- FOR SALE: 20 back issues of BYTE (from Febru- Hayes board, $50. All bare boards with sockets mable memory board. Ideal for hardware oriented ary 1976). Best offer takes all. Norman G Church, installed. TDL Macroassembler, text output beginner. Asking $250. Randy Soderstrom, 4601 18310 Franklin Way, Gladstone OR 97027, (503) program, ZTel. Zapple, text editor. $120 for Goldfinch, Madison WI 53714, (608) 222-8056. 659.6763. all software. Kim, Calgary CANADA. 283.6863.

December 1978©BYTE Publications Inc 247 To get further information on the products advertised in BYTE, fill out the reader service card with your nome and address. Then circle the appropriate numbers for the advertisers you select from the list. Add o 15 cent stamp to the card, then drop it in the mail. Not only do you Header Service gain information, but our advertisers are encouraged to use the marketplace Provided by BYTE. This helps us bring you o bigger BYTE.

Inquiry No. Page No. Inquiry No. Page No. Inquiry No. Page No. 297 Page Digital 735 1 AAA Chicago Computer Center 207 134 EMM /Semi 182 6 Addmaster Corporation 236 138 Escon 187 298 PAIA Electronics 172 PCE 2 Administrative Systems 161 140 Forethought Products 190 288 Electronics 206 301 PerCom Data 75 3 AJA Software 201 148 Gamma Technology 238 4 Alpha Micro Systems 82. 83 150 Godbout 105 289 PerSci Inc 15 12 Altos 42 153 Graham Dorian Enterprises CIII 302 Personal Software 91 8 Ambico 171 156 GRT Corporation 33 303 Personal Systems Consulting 106 9 Apparat Inc 236 217 H & E Computronics 183 306 Priority 1 231, 232, 233 14 Apple Computer 8 157 Hamilton Logic Systems 242 305 Processor Technology 6.7 15 Apple Computer 9 160 Heath Company 17 Program Design Inc 159 Art.by.Computer 173 161 Heath Company 236 309 PRS Corporation 71 10 Artec Electronics 113 170 Hobby World 211 311 Ouest Electronics 239 11 Artec House 125 173 Houston Instruments 35 304 Radio Shack Authorized Sales Center 244 22 ATV Research 242 172 HUH Electronics 197 322 RCA 44 23 AVA Electronics 238 174 Idea Assemblers 244 ' Real World Simulations 201 24 Axiom`21 171 Infinite 244 307 The Recreational Programmer 142 26 Base 2 Inc 63 777 Integral Data Systems 92.93 319 Rochester Data Inc 244 28 Basic Computer Shop 242 179 Integrand 192 313 Rockwell 160 30 Beckian Enterprises 245 180 Integrated Circuits Unlimited 225 314 Rondure Co 243 31 Benchmark Computing Services 236 181 Intelligent Design 236 328 Rothenberg Information System 167 34 Beta Business Systems 242 184 International Data Sciences 126 316 S-100 196 35 BITS 133. 136. 138, 139. 155 190 Ithaca Audio 81 337 Saddle Brook Stereo Inc 244 33 Byte Industries 162 Ithaca Audio 215 Scientific Research 67. 73, 78 BYTE Back Issues 203 195 Jade213 Scelbi 49. 52. 53, 61 BYTE Subscribers 203 200 Jameco Electronics 226, 227 Scelbi /BYTE Primer 137 BYTE WATS Line 203 Leland Sheppard 173 318 Seattle Computer Products 115 32 Buss /Charles Floto 208 Lifeboat Associates 201 323 Semionics 164 39 California Digital 217 212 M. M. & S Software 236 319 Michael Shrayer Software 143 43 Cambridge University Press 208 211 Manchester Equipment 244 312 Shugart CIV 83 Career Advertiser 244 213 The Math Box 242 327 Silver Spur 236 45 Central Data 107 220 Meca 180 328 Small Business Computer Magazine 158 46 Chrislin Industries 188 218 MicroiAp 165 320 Smoke Signal Broadcasting 27, 189, 191 48 Circle Enterprises 236 n5 Micro Diversions 57 326 Sofnide 141 47 Compugard Corp 244 219 MicroDaSys 19 321 Software 80 198 53 Computalker 150 216 Micro Focus LTD 147 340 Solid State Sales 237 65 Computer Corner 157 222 Micro Mail 167 350 Southwest Technical Products Corp CII 70 Computer Enterprises 157. 204 223 Micromation 31 355 SSM 80 Computer Factory 127 201 Micro Mike's 190 352 Stirling Bekdorf 122 71 Computer Hardware Store 236 227 Microproducts 200 351 Structured Systems Group 121 74 Computer Interface Technology 238 221 Microprogramming 245 353 Structured Systems Group 142 72 Computer Lab of NJ 183 224 Micro Pro International 77 356 Summagraphics 79 75 Computerland 10. 11. 87. 191 202 Microtronics 176 357 Sybex Inc 181 76 Computer Mart of NH 238 203 The Micro Works 129 355 Synchro Sound 103 73 Computer Mart of NJ & PA 171 226 Micro World 51 359 Talos 174 78 Computer Plus 196 229 MikOs 230 358 Tano 145 79 CP Aids 187 255 Morrow/Thinker Toys 23. 97 360 Tarbell Electronics 117 77 CT Micro Computer 183. 206 257 Motorola Semiconductor Products Inc 175 370 Technical Systems Consultants 123 82 Control Data Corp 177 265 mpi 200 373 Telecommonicetions Services 238 80 Cromemco 1. 2 267 Mullen Computer Boards 207 343 Terrapin 99 84 CyberiScore t78 279 National Multiplex Corp t49 377 Terminal Systems 238 91 Data Discount Center 182 280 Netronics Research 163 356 3 S Sales 243 81 Detefecs t 73 281 New England Electronics 109 346 Tore Systems Limited 238 93 Deteseerch 173 293 New England Personal & Business Computer Show 95 382 Total Information Services 195 85 Detec Inc 244 282 New England Recruiters 242 378 Trans Data Corp 183 89 Digital Pathways 144 283 Newman Computer Exchange 229 348 Transition Enterprises 189 95 Digital Research (CA) 119 285 North Star Computer 5, 29 374 TransNet Corp 172 100 Digital Research (TX) 219 286 Northwest Microcomputing Systems 59 376 Tri Tek 234 102 Digital Research & Eng t99 287 Necleonic Produce 111 University Microfilms International 203 110 Dynebyte 12, 13 290 Ohio Scientific Instruments 37. 40, 41 383 US Robotics 198 113 EdiPro t65 291 OK Machine & Tool 99 3134 Vamp 242

115 Electrolebs 230 293 Oliver Advanced Engineering 199 386 Vector Electronics 1 79 117 Electro Analytic Systems 192 284 Optimal Technology 238 387 V R Data Corp 242 120 Electronic Control Technology 205 292 Osborne & Associates 131 388 Warnaco 241 t25 Electronic Systems 22t Owens Associates 242 395 Worldwide Electronics 238 130 Electronics Warehouse 223 294 Pacific Digital 197 400 Rite', 184 t32 EMM /CMP 166 296 Pacific Of lice Systems 234 401 xitex 185 'Correspond directly with company.

COMe- BYTE's Bogoiog Mooilo) Box Pascal Blazes Into First Place "A 'Tiny' Pascal Compiler, Part 1," page Article No. ARTICLE PAGE 58, by Chung and Yuen placed first in the September BOMB. Second place went to 1 Stanley- Peterson: Fast Fourier Transforms on Your Home Computer 14 "WADUZITDO," page 166, by Larry 2 Munnecke: Designing a Universal Turing Machine 26 Kheriaty. These articles placed 2.0 and 1.5 3 Ciarcia: Build an Octal /Hexadecimal Output Display 32 4 MilliunReardonSmart: Life With Your Computer 45 standard deviations above the mean, respec- 5 Buckingham: Some Facts of Life 54 tively; first and second prizes of $100 and 6 Millen: One -Dimensional Life 68 $50 will be sent to the authors. In third 7 Douglas: Chess 4.7 versus David Levy 84 place was The Mathematics of Computer 8 Astmann: Interface Your Computer to a Printing Calculator 94 9 Gable: Zapper: A Computer Driven EROM Programmer 100 Graphics," page 22, followed by "Graphic 10 Weisbecker: An Easy Programming System 108 Manipulations Using Matrices," page 156, 11 Gerhold: Teaching With a Microcomputer 124 in fourth. 12 Weed: Clockless Multiplication and Division Circuits 128 The BOMB (BYTE's Ongoing Monitor 13 Frey- Atkin: Creating a Chess Player, Part 3 140 is in which readers 14 Halsema: Partitioned Data Sets 168 Box) our monthly forum 15 Willard: The Mother Chip 186 rate the articles in BYTE. To participate, 16 Maurer: FORTRAN and its Generalizations 194 see the card at right.

248 December 1978 © BYTE Publications Inc MASI C-72 "I own a fast -growing business and before I "I'm glad I went with Shugart drives. Look, bought my computer system I put in a lot of late when you lay out your own money for a system, hours keeping up with my accounting and you want dependable performance and good inventory control. Now the computer does my value. Do what I did. Ask for the system with the number crunching quickly, so I have time after minifloppy." hours to have some fun with the system. My son and I started out playing Star Trek on the system, and now we're learning to play chess. If it isn't Shugart, "When I was shopping around for my system, the guys in the computer stores demonstrated all the unique features of the minifloppy. I've got to it isn't minifloppy. admit that at first I didn't really understand all the technical details. But now that I use the system every day, I really appreciate the minifloppy's fast Shugart Associates random access and data transfer. I like the reliability, too. 435 Oakmead Parkway, Sunnyvale, California 94086

For a list of manufacturers featuring Shugart's minifloppy in their systems, circle reader response number. TM minifloppy is a registered trademark of Shugart Associates Circle 312 on inquiry card.