October 1979 S2.50 kilobaud MICROCOMPUTING for business . . . education . . . FUN!

In This Issue—35 Articles Including: Special Emphasis on 6800 Systems Six Articles The World Power Systems Scam page 56 Exatron's Stringy Floppy: a Mass Storage Alternative page 98 Ulysses in Computerland: in Quest of Business Systems page 128 Inexpensive Logic Analyzer page 172 Complete Table of Contents on page 5. Fpcot PEflGCM

One-Drive System: S399. (40-track) & $675. (77-track) Two-Drive System: S795. (40-track drives) & S1350. (77-track drives) Three-Drive System: $1195. (40-track drives) & S2025. (77-track drives) Requires Expansion Interface. Level II BASIC & 16K RAM

Low Cost Add-On Storage for Your TRS-80*. In the Size You Want. When you're ready for add-on disk storage, we're ready for you. Ready with six mini-disk storage systems — 102K bytes to 591K bytes of additional on-line storage for your TRS-80*.

• Choose either 40-track TFD-100™ drives Whether you need a single, 40- — 197K, 394K and 591K bytes for one-, or 77-track TFD-200™ drives. track TFD-100™ add-on or a three-drive two and three-drive systems. add-on with 77-track TFD-200™s, you PATCH PAK #1™, our upgrade • One-, two- and three-drive systems im- get more data storage for less money program for your TRSDOS*, not only mediately available. from Percom. extends TRSDOS* to accommodate 40- and 77-track drives, it enhances • Systems include Percom PATCH PAK Our TFD-100™ drive, for example, TRSDOS* in other ways as well. PATCH #1™, on disk, at no extra charge. PATCH lets you store 102.4K bytes of data on PAK #1™ is supplied with each drive PAK #1™de-glitches and upgrades one side of a disk — compared to 80K system at no additional charge. bytes on a TRS-80* mini-disk drive — TRSDOS* for 40- and 77-track operation. The reason you get more for less and 102.4K bytes on the other side, too. from Percom is simple. Peripherals are Something you can't do with a TRS-80* • TFD-100™ drives accommodate "flippy not a sideline at Percom. Selling disk drive. That's almost 205K bytes per disks." Store 205K bytes per mini-disk. systems and other peripherals is our mini-disk. • Low prices. A single-drive TFD-100™ main business — the reason you get costs just S399. Price includes PATCH And the TFD-200™ drives provide more engineering, more reliability and PAK #1™ disk. 197K bytes of on-line storage per drive more back up support for less money. > Enclosures are finished in system- In the Product Development Queue ... a printer interface for using your TRS-80' with any compatible "Tandy-silver" enamel. serial printer, and ... the Electric Crayon™ to map your computer memory onto your color TV screen — for games, animated shows, business displays, graphs, etc. Coming PDQ!

™ TFD-100. TFD-200 PATCH PAK and Electric Crayon are trademarks ot PERCOM DATA COMPANY •TRS-80 and TRSOOS are trademarks ol Tandy Corporation and Radio Shack wtiich have no relationship to PERCOM DATA COMPANY

To order add-on mini-disk storage for your TRS-80*, or request additional literature, call Percom's toll-free number: 1-800-527-1592. For detailed Technical infor- mation call (214) 272-3421. PERQOM Orders may be paid by check or money order, or charged to Visa or Master Charge credit accounts. Texas residents must add 5% sales tax. PERCOM DATA COMPANY, INC. 211 N. KIRBY • GARLAND. TX. • 75042 Percom peripherals for personal computing' E NTRTEC DATA SYSTB^IS I SUPRBRAIN

The Honor Graduate There's been a lot of talk lately debugger. And, with SuperBrain's office typewriter. Sophisticated about intelligent terminals with S-100 bus adapter, you can even add users will acclaim SuperBrain's twin small systems capability. And, it's a 10 megabyte disk! Z-80 processors which transfer data always the same. The systems More than an intelligent terminal, to the screen at 38 kilobaud! Inter- which make the grade in perfor- the SuperBrain outperforms many facing a printer or modem is no mance usually flunk the test in other systems costing three to five problem using SuperBrain's RS- price. At least that was the case times as much. Endowed with a 232C communications port. But best of all, you won't need a PhD in com- until the SuperBrain graduated with hefty amount of available software puter repair to maintain the Super- the highest PPR (Price/Perfor- (BASIC, FORTRAN, COBOL), the SuperBrain is ready to take on your Brain. Its single board design makes mance Ratio) in the history of the servicing a snap! industry. toughest assignment. You name it! General Ledger, Accounts Receiv- So don't be fooled by all the fresh- For less than $3,000*, SuperBrain able, Payroll, Inventory or Word Pro- man students in the small systems users get exceptional performance cessing ... the SuperBrain handles business. Insist on this year's honor for just a fraction of what they'd all of them with ease. graduate ... the SuperBrain. expect to pay. Standard features in- Your operators will praise the clude: two dual-density mini-flop- SuperBrain's good looks. A full = NTE3TEC pies with 320K bytes of disk storage, ASCII keyboard with a numeric key- 64K of RAM to handle even the most pad and function keys. A non-glare, DATA sophisticated programs, a CP/M • dynamically focused, twelve inch Disk Operating System with a high- = SYSTEMS screen. All in an attractive desktop 2300 Broad River Road, Columbia, SC 29210 powered text editor, assembler and unit weighing less than a standard (803) 798-9100 TWX: 810-666-2115

•Quantity one. Dealer inquiries invited. Solve your personal energy crisis. Let VisiCalc Power do the work. With a calculator, pencil and paper you can spend hours plan- Or say you're an engineer working on a design problem and are ning, projecting, writing, estimating, calculating, revising, erasing wondering "What if that oscillation were damped by another 10 and recalculating as you work toward a decision. percent?" Or you're working on your family's expenses and Or with VisiCalc and your Apple* II you can explore many wonder "What will happen to our entertainment budget if the more options with a fraction of the time and effort you've spent heating bill goes up 15 percent this winter?" VisiCalc responds before. instantly to show you all the consequences of any change. VisiCalc is a new breed of problem-solving software. Unlike Once you see VisiCalc in action, you'll think of many more prepackaged software that forces you into a computerized uses for its power. Ask your dealer for a demonstration and dis- straight jacket, VisiCalc adapts itself to any numerical problem cover how VisiCalc can help you in your professional work and you have. You enter numbers, alphabetic titles and formu- personal life. las on your keyboard. VisiCalc organizes and displays this You might find that VisiCalc alone is reason enough to information on the screen. You don't have to spend your own a personal computer. time programming. VisiCalc is available now for Apple II computers, with Your energy is better spent using the results than forother personal computers coming soon.The Apple gettiitg them. II version costs just $99.50 and requires a 32k disk system. Say you're a business manager and want to project For the name and address of your nearest VisiCalc your annual sales. Using the calculator, pencil and dealer, call (408) 745-7841 or write to Personal paper method, you'd lay out 12 months across a Software, Inc., Dept. K, 592 Weddell Dr., sheet and fill in lines and columns of figures Sunnyvale, CA 94086. If your favorite on products, outlets, salespeople, etc. You'd dealer doesn't already carry Personal calculate by hand the subtotals and summary Software products, ask him to figures. Then you'd start revising, erasing give us a call. and recalculating. With VisiCalc, you simply fill in the same figures on an electronic "sheet of paper" and let the computer do the work. Once your first projection is complete, you're ready to use VisiCalc's unique, powerful recalculation feature. It lets you ask "What if?',' examining new options and planning for contingencies. "What if" sales drop 20 percent in March? Just type in the sales figure. VisiCalc instantly updates all TM—VisiCalc is a trademark of other figures affected by March sales. Personal Software, Inc. 'Apple is a registered trademark of Apple Computer, Inc. kilobaud micro info T.M. [Iji This symbol next to a title in MICROCOMPUTING ™ the table of contents indicates that the article is a business- application article. Manuscripts Contributions in the form of manu- contend och '79 scripts with drawings and/or photo- graphs are welcome and will be con- sidered for possible publication. We The SWTP Computer System First ot a two-part series on disks for SWTP P. Shuman, P Stark 30 can assume no responsibility for loss or damage to any material. Please PAIA 8700 Revisited Continuing coverage ot the 8700. This time-making music. Rod Hallen 40 enclose a self-addressed, stamped Inexpensive TRS-80 Printer Interface Small System Hardware's TRS-232. Sherman P. Wantz envelope with each submission. Pay- 44 ment for the use of any unsolicited 46 Eyes for the AC-30 Mod to add monitoring features to the AC-30. Jerry Sorrels material will be made upon accep- tance. All contributions should be di- 48 Expanded TRS-80 Disk Operations First in a two-part series. Allan J. Domuret rected to the Microcomputing editorial offices. "How to Write for 56 Anatomy Of a Scam The World Power Systems scam and how it fell apart. Terry Kepner Microcomputing1' guidelines are available upon request 60 jjj Business Software Made Easy A business-software-writing primer. Ernie Brooner 64 KIMCTR Measures Capacitance An enhancement to KIMCTR (May 1979). Clement S. Pepper Editorial Offices: 72 More TRS-80 Horsepower Adding 16K of memory and "Level III" BASIC. Ronald W. Cowart Pine Street Peterborough NH 03458 78 Probos V Build an inexpensive, effective logic probe. Sreve Dominguez Phone: 603-924-3873, 924-3874 82 PET'S Keyboard Grows Up Send your Munchkin-size keyboard to Oz. Robert W. Baker Advertising Offices: Hurricane! Track hurricanes with this program. Bryce Segar 84 Elm Street Peterborough NH 03458 88 Video DMA Interface for SWTP Systems Add direct memory access. D. Holten, J. Boehme Phone: 603-924-7138. 924-7139 94 Ultimate Consumer Computer This British-initiated system will be available in the U.S. Frank J. Dertler Circulation Offices: 98 The Exatron Stringy Floppy An alternative to cassettes (slow) and disks (expensive). Bill Harvey Elm Street 102 Calendar Program What will the boys at the service station say? Sreve Tabler Peterborough NH 03458 Phone: 603-924-7296 104 Four More Commands for SSB DOS Increase the BFD-68 repertoire Terry Perdue

110 Arena Go into battle with your computer Richard Price To subscribe, renew

116 File Directory Analysis for North Star DOS organize your NS disk files Edwin Mime or change an address: Write to Microcomputing, Subscrip- 120 Report on the Centronics 779 Printer An "opinionated but accurate" evaluation. Glen A. Deibert tion Department, PO Box 997, Farm- ingdale NY 11737. For renewals and 122 Beefing Up PET Get machine language and BASIC in your PET. Kendal T. Rogers changes of address, include the ad- 124 AMI'S EVK Series Part 1 of a three-part series on a 6800 alternative. David L. Tietz dress label from your most recent issue of Microcomputing. For gift 128 jj Ulysses in Computerland Obstacles in setting up a business system. J. Craig McLanahan subscriptions, include your name and address as well as those of gift recip- 132 Apple's Documentation Strikes Again The Apple ll Programmer s Aid ROM. Kenneth Miles ients. Postmaster: Send change of address information to Microcom- 134 Caps Lock, Not Shift Lock Give your shift fingers a break. Dr. Michael R. Dunlavey puting, PO Box 997, Farmingdale NY 11737. 136 Hardware Random Number Generator Try a hardware approach. Ken Barbier 138 Bit Rate Clocks for Your Serial Interface An alternative to all the UART applications, fl. ft Derynck Subscription problem or question: 150 Exploring the Inequality of Bus Buffers All buffer chips are not created equal. John R. Cameron Write to Microcomputing, Subscrip- 154 Elfish Ideas Speed up your Elf's input-output. Glen A. Popiel tion Department, PO Box 997. Farm- 158 ingdale NY 11737. Please include an Load Programs the SIMPL Way Check out this author's loader; you might use it too. Harold B. Combs address label. 162 Pig Latin Is this the ultimate in program protection? Ken Klosson

166 Touch Handle with care! This icebreaker could be a jawbreaker Adrian R. Thornton Kilobaud Microcomputing (ISSN 0192-4575) is published monthly by 170 Program Debugging Straighten out misbehaving programs. Bob Bosen 1001001, Inc., Pine St., Peterborough NH 03458. Subscription rates in U.S. 172 Hardware Testing in Suspended Animation Build an inexpensive logic analyzer K. D. Tentarelli are $18 for one year and $45 for three years In Canada: $20 tor one year and 176 Sweetening the Bytesaver Increase the Bytesaver's usefulness with this mod. Steven K. Roberts $51 tor three years In Europe, send 89,-DM in Euroscheck or send credit card information to: Monika Nedela. Publisher's Remarks-6, Output from Instant Software, Inc.-8, Books-9, Markstr. 3, D-7778 Markdorf. W. Ger- PET-pourri —16, New Products-21, Letters-27, Classifieds-108, Contest!-108, many. South African Distributor: KB Microcomputing, PO Box 782815, Dealer Directory-109, Corrections-109 Sandton, South Africa 2146 Austra- lia: For subscriptions write — Katherine Thirkell. Sontron Instru- ments, 17 Arawatta St.. Carnegie, Vic. 3163 Australia. All other foreign sub- scriptions are $23—one year only (surface mail). Second-class postage paid at Peterborough NH 03458 and at additional mailing offices. Phone: 603-924-3873. Entire contents copy- Cover This month's cover shows the Exatron Stringy Floppy (ESF) in use as the mass-storage subsystem for the SWTP right 1979 by 1001001, Inc. No part of microcomputer. The ESF fills the gap between the standard cassette and the floppy disk. For less than the cost of the lat- this publication may be reprinted or ter, the ESF provides comparable reliability and eliminates the aggravation of slow operating speeds and high error rates otherwise reproduced without written of most cassette systems. For more information on the ESF see pages 15 and 98. permission from the publisher PUBLISHERS REMARKS Wayne Green

Three? Five? Ten? Let's take two, delivering programs and promo- stores per rep area . . . right now. Like to Make $20,000 so we'll be sure to be underesti- tion materials. One should have a Can you sell TRS programs to A Month? mating in every way. 1 think there familiarity with microcomputers, Radio Shack stores? If you can't, will be more like 500 stores in each with selling, with bookkeeping, then you sure should stay in some Yes, I know: It sounds in- area within a couple years. I'll be with software, plus the determina- other business. Better go get a teresting if the work isn't too hard disappointed if Instant Software tion to succeed. degree as an engineer and not have and the hours not too long. does not have 1000 programs re- It will take some time to develop to work again. There is a need, I feel, for the leased by mid-1980. But taking the a reputation and to build up com- development of manufacturers' low-ball estimate of 500 programs, missions. Of the 50 stores in an representatives in the microcom- two average per month per store, area, probably no more than five Paris Micro/Expo puting industry. I was making we come up with retail sales per or ten are already stocking Instant some calculations of what a rep store per month totaling $15,000. Software ... the rest will have to Sybex's micro show in Paris was might be able to earn to see if the Fifty stores will make $750,000 in be sold. There will be resistance well attended, with some very field is attractive enough to bring sales for the rep in his area. A rep . . . there always is to something familiar names exhibiting. Here people into this business. The would thus get a 10 percent com- new, no matter how beneficial it are some more photos of people figures look good. mission on wholesale ... or about is. Some dealers won't want to and exhibits at the show. Let's say we divide the country $45,000 per month commissions. carry software for the TRS-80 be- into about 20 areas. With about If it turns out that there are cause they aren't selling it. This 1000 computer stores currently in 10,000 stores instead of 1000 sell- means you'll have to show them business, this would allocate about ing computers, multiply the above how this will bring more cus- Software Support Critical 50 stores per area. This is probably figure by 10. If we have twice or tomers into their store and permit all one rep could handle without three times the number of pro- them to take advantage of the Several of the smaller manufac- hiring assistants, since he is going grams released, double or triple rapidly growing and highly lucra- turers of microcomputer systems to have to get around to most of that number. If I'm wrong and tive market in accessories for the haven't thought very far ahead these stores at least once a month. sales are only one tenth of my TRS. It means showing the dealer and as a result are not aware of the What would the rep do? Well, if estimate that is still $4500 a month that most newcomers to com- importance of software to their we take as an example a rep for In- in commissions per rep. puting are coming in via their pur- sales when the time comes that stant Software, he would check If I'm near right in my projec- chase of a TRS or other small sys- other systems have a large supply the display in a store, make sure it tions, we're going to have a bunch tem rather than as a hobbyist, as it of inexpensive software. was a couple years ago. is well placed, make sure it is well of millionaire reps. Let's exaggerate just a trifle to stocked, that all the newest re- Stores won't be doing badly But even with five dealers and get the concept. Let's suppose that leases are prominent, that our either. At the low figure of only 100 program packages and a prospective microcomputer posters are on display, that store $15,000 sales per month, their with the average retail price at $8, customer has been lured into a clerks know how to demonstrate profit will run about $6000! A a rep can right now, without store and is looking over system A the new programs, answer any library of 5000 programs would growth, make nearly $500 per vs system B. One has the support questions on programs from bring in around $60,000 in profit month in commissions. Each extra of several thousand programs- clerks, replace any troublesome per month! store brought on line should in- some right down his alley for programs, report to the factory on So how can one get into this crease the monthly commissions business, some just a help in his sales, on any problems, on good lucrative rep business? This is not by a minimum of $160. business, plus some games, securi- vibes and anything else of value to for the lazy. It means working If we add in the 2300 Radio ty, data base, word processing, the factory. hard seven days a week for a long Shack associate stores and fran- etc., which look good. The other As the library of programs in- time building up the business. It chise stores, all of which have the system has no programs available creases, a rep is going to have his means having a car so you can get freedom to deal directly with In- at all. The price on the two systems hands full keeping stores in stock to all of the dealers . . . and even- stant Software through a rep firm, is similar. Which do you think he and keeping records of sales, mak- tually a van or even truck for we're adding about 115 more will buy? ing sure the billing is correct and that stores stay on time with pay- ments. This isn't much of a prob- lem when there are only 100 pro- grams, but Instant Software is aiming at supporting a library of several thousand business, scien- tific, educational, game and home programs. Every store will have a program library, which will be a large part of their business, prob- ably accounting for much more sales and profit than hardware. But let's say that our rep is han- dling just 50 stores, that there are only 500 programs so far released (one year from now at the latest), Here is the Heath exhibit. Actually, the interest in that the average retail price of the kits seemed to be less than expected, so the new programs is about $15 ($8 for Heath line of assembled units will probably better games, $15 for educational pro- fit the European temperament. Europeans don7 One of the most crowded booths alt through the grams and $100 for business) and seem to be interested to a high degree in the hobby show was the Tandy booth. The TRS-80 is a best that each store sells an average of aspect of microcomputers, but rather in using them seller in some parts of Europe, and just getting . . . how many? Two per month? for practical business and scientific applications. started in others. •E: laoboua MICROCOMPUTING "

PUBLISHER/EDITOR Wayne Green EXECUTIVE VICE PRESIDENT Sherry Smythe ASSISTANT PUBLISHER/EDITOR Jeffrey D. DeTray MANAGING EDITOR John Barry EDITORIAL ASSISTANTS Dennis Brisson Susan Gross ADMINISTRATIVE ASSISTANT Dotty Gibson PRODUCTION DEPARTMENT MANAGER: Noel R. Self Sybex did a brisk business in their books, some of Reinhard Nedela and Sherry were busy at the Kilo- STAFF: which have now been translated into German and baud Microcomputing booth with subscriptions Cathy Callahan and Instant Software sales. Robert Drew French. James H. Gray II Bruce Hedin Carl Jackson suckered into buying these pro- have both the hardware available Ken Jackson Actually, the prices of the two Dion Owens systems will not be similar because grams, which are usually pub- and the language and operating Patrice Scribner the software support of one sys- lished at a higher price than the system before you can get a good Robin M. Sloan John W. White tem will so increase its sales that better programs 1SI is publishing. start. TYPESETTING there will be substantial cost The growth of software publish- Much of the business software now coming into Instant Soft- Barbara J. Latti reductions to pass along to the ing has been held back to some Sandie Gunseth customer . . . and to the dealer in degree by the costs of lab hard- ware for publication has been Mary Kinzel terms of higher profits. A dou- ware. The more money that has to developed by individual pro- Holly Walsh bling of production in this field be put into hardware, the less is grammers for custom applica- PHOTOGRAPHY available for salaries and the peo- tions . . . often in conjunction W. H. Heydolph seems to result in a dropping of Tedd Cluff manufacturing costs of about 25 ple needed to get the work done. with a local Radio Shack store. Terrie Anderson percent. This can mean a drop of Manufacturers may eventually Some of these programs are in- PROJECTS EDITOR about four times that to the recognize this and work out some dicative of what we can expect in Jim Perry customer. system for helping software the future—programs, for in- ASSOCIATE EDITORS Unfortunately for the systems publishers with their work . . . stance, for specific hospital func- Phil Feldman and with equipment. tions, for working with blood Rod Hallen manufacturer who does not push Len Lindsay hard for software support, the testing systems to speed up their Tom Rugg more software developed for an- operation and print out the Peter Stark results of hundreds of tests, to Sherm Wantz other system, the more will be Ken Widelitz developed. It is self-generating. Business Software work with patient monitoring BOOKKEEPER And the more software there is, equipment to keep a record of Knud E. M. Keller the better all of it is going to be. In- The development of top-notch many factors and alert someone MARKETING/CIRCULATION MGR. stant Software is getting much business software for microcom- if anything gets out of acceptable Robert LaPointe more selective about the software puters is, as I predicted, taking a parameters, to determine the BULK SALES MGR. lot longer than games . . . and doses of certain medicines from Judy Waterman being accepted for publication. ASST. CIRCULATION MGR. With some dismay, we are already for obvious reasons for anyone tests by other equipment. seeing our rejects coming on the who gives it any thought. It takes We'll be seeing this depth of Donna Taylor ASST. MARKETING MGR. market from smaller publishers, a lot of time, experience and business software developing in genius to write really good busi- many fields. We've already some Harold Stevens and we know that disappointment CIRCULATION ness programs; plus you have to surprisingly sophisticated real is ahead for the people who get Pauline Johnstone COMPUTER PROGRAMMING Richard Dykema INSTANT SOFTWARE MICRO LAB William F. Gollan Scott Spangenberg Palmer T. Wolf Stan Wszola EUROPEAN MARKETING DIR. Reinhard Nedela AUSTRALIAN DISTRIBUTOR Katherine Thirkell

—ADVERTISING - Aline Coutu. Mgr. Bill York Marcia Stone Nancy Ciampa Gaye Halbig Lori Mugford Rita Rivard Eve Anderson Kevin Rushalko Carol Symonowicz estate packages, but they are As a publisher, I can look for- Add in the replies to various polls, with the BASIC ROM, which nothing to what we'll have in a ward to word processing helping and you have more need for com- comes built in. year or two when most brokers prepare material for publication. puters to provide a better product The Apple II came with Integer will not only have immediate in- Computers can then be used to lay at a lower price. BASIC installed, and you had to formation on their inventory, but out pages and set them ready for The microcomputer will be able add Applesoft via a plug-in board also data on all neighboring inven- printing, even to making the print- to help every business to operate at to get floating point numbers, tories and a wide range of calcula- ing plates directly. Editors can use lower cost and with more efficien- high-resolution routines and a tions possible on the myriad of a computerized index to list pub- cy. Plus it will take a lot of the much more complete BASIC. The methods for financing real estate. lished material for fast referenc- drudgery out of the work by doing Apple II + system has the Ap- The forms will be done automati- ing. Computerized soliciting of most of the routine. I think we will plesoft built in, and you have to cally, along with all billing, title bids for printing and paper will be seeing all of these programs plug in an Integer BASIC card to search and legal aspects. provide efficiencies and cut costs. evolving for microcomputers, and run your programs written in that I had to laugh at the innocence Computerized mail will speed I'm hoping that Instant Software version ... or to speed up some of one manufacturer who thinks material for publication from will be the major distributor of functions. Delivery is expected of microcomputer business soft- remote writers and editors. Com- these programs ... all over the soon on the Integer BASIC ware as a "bad joke . . . written puters can help with determining world. boards. by amateurs." I hope he keeps his the imposition of pages on a larger In May we opened up Europe The Instant Software Apple non-micro business going ... he press. Computers help work out for software distribution. South programs—Golf (0018A), Bowl- may need it. Many of the pro- the best ratio of advertising to Africa should be next in Septem- ing (0040A), Math I (0073A), grams we are seeing are being writ- editorial material, taking into con- ber. Asia will be opened up in Oc- Math II (0098A)—are mostly in ten by old-time professional pro- sideration the number and place- tober. The more outlets for soft- Applesoft. Trilogy (0040A) and a grammers, some with PhDs in ment of two-color ads, three-color ware there are, the more royalties second run of Math I (0040A) are computer science. Being a PhD ads, four-color ads and editorial for the programmers . . . and the in Integer BASIC. Apple owners doesn't mean you are stupid and material with color. better programs we'll have to help not having both languages should don't know where the money is, Then we need computers to take sell systems. Will systems with be careful when buying packaged and the big money for the free- care of daily orders from in- poor software support sell? I can't programs and make sure they lance computerist lies in soft- dividuals for current and back think of any reason they should. match the ROM they're using. ware—business software right issues. Computers can also handle now, then educational, and finally orders from dealers and whole- all kinds. Computers can handle salers. Computers will speed up Ripped Off? just about any timesaving applica- shipping and billing, bookkeep- New Apple! tion once the programs are avail- ing, handling plastic money, keep- If you have a serious problem able. I will again predict that the ing an inventory record and sales Though I've seen no releases yet with a microcomputer firm, send eventual uses for our microcom- records of all transactions. These, from Apple, the stores are now them a letter with all the facts in puters will surprise all of us. The in turn, will provide reports for the selling a new model, the Apple detail, plainly and simply, and surface is just being scratched and, circulation people so they know II +. We'll probably hear more send a copy to me. Kilobaud as new programs are developed, which ads are working best and about the changes involved, but Microcomputing protects its read- the need for more will follow. what covers sell better than others. the immediate difference has to do ers more than any other magazine.

OUTPUT FROM ISI Sherry Smythe

The number of programs avail- tant to stock programs for systems developing program packages for used. Should the day come when it able for microcomputers is grow- other than those they are selling. them for mass publication. seems better to sell a program on a ing slowly; most of the new entries The dealers who are stocking pro- The crew at Instant Software disk. Instant Software will go that still are games. Dealers are not en- grams for all systems are finding has been growing. The programs route. In the meantime, most pro- thusiastic about this. They prefer that their program sales are sub- are now all cataloged on a TRS-80 grams—even the disk-based pro- to see business-oriented software stantially better as a result. with a couple disks, as are the grams—are easily transportable since these programs will not only Perhaps 85 percent of the new- associate editors and their spe- via cassettes, and this saves some provide program sales, but also comers to microcomputing these cialties. There is more and more money. will help to sell their systems. days are entering via a TRS-80, work for associate editors as more We're geared up to check out Oddly enough, one of the best and stores with no TRS-80 prod- programs are being translated for and produce programs based on business programs released ucts are effectively chasing away use on more systems and also into NEWDOS, which is getting very (Business Cycle Analysis, a power- their best sales prospects. foreign languages ... in addition good marks from users. Judging ful management tool) so far has Prospects for business pro- to the usual evaluations of newly from reader reports, it appears to been for the TRS-80, and Radio grams are better and better. About submitted programs. be superior to TRSDOS. Shack stores are prohibited from half the programs now being sub- selling programs other than those mitted for publication by Instant released from Ft. Worth. This Software are business-oriented. may be costing stores thousands of Oh, the umpteenth financing pro- Disks Educational Programs computer sales and costing Radio gram arrived long ago and aroused Shack into the millions. Mean- as much interest as another ver- Increasing numbers of pro- Games are not needed. Pro- while, computer stores are en- sion of Hangman or Mastermind. grams are being submitted on grams already listed as available joying the bonanza, and TRS-80 When you consider how many disks, which is fine with us. There are not badly needed. Educational owners are forced to find their business programs there are to be is little reason for a business, even programs are very much in de- neighborhood computer store to written, you wonder at this rein- a small business, not to invest in at mand. But look here—if you are get any serious support for their venting of the wheel. Many pro- least a dual-disk system. Without going to write a program to teach system. grammers are now getting to- that minimum of on-tap memory, Many dealers have been reluc- gether with business friends and few significant programs can be (see OUTPUT, page 190) BOOK REVIEWS

ent and fully decoded address kits produced these days. The first if cheap video is for you without The Cheap Video Cookbook lines. Some systems just cannot part of this chapter discusses cir- unnecessarily investing money Don Lancaster meet these requirements without cuit theory and the construction of that would have been better spent Howard W. Sams & Co.. Inc. additional hardware, which means Don Lancaster's latest TVT, the on some more RAM or even an- Indianapolis IN more $$$. TVT 6-5/8. All components are other book. If you opt for the lat- 1978, 256 pp., paperback installed one by one, and each step ter method, 1 suggest you hide Since the video interface de- is checked off after completion. behind a bookshelf to avoid evil scribed in the book was designed There are also several excellent looks from the shopkeeper! All of us at one time or another for 6500- and 6800-based systems, full-size patterns for the PC have probably yearned for a video computers with such chips as the Ste>e Dominguez boards and solder mask. In addi- terminal. Some of us were rich F-8, SC/MP, 1802 and even the Golden CO tion, chapter 4 contains complete enough to afford one, but the rest 8080 will require modification to construction details for four addi- of us had to be content to struggle be compatible. Depending on the tional add-on modules that give with our eight puny data LEDs un- system, these modifications could the TVT 6-5/8 extra features such til the day came when we could af- be extensive and difficult. Not on- Programming in PASCAL as graphics (black and white and ford a good terminal for our own. ly that, but the software will have Peter Grogono color) and lowercase alphanu- Well, that day has arrived. Don to be translated as well. In short, Addison-Wesley, Inc. merics. With the TVT 6-5/8 and Lancaster has come to our rescue conversion to another CPU will 1978, $10.95 each module is a troubleshooting with his latest "cookbook," The introduce new problems and take Cheap Video Cookbook, which guide to help isolate errors in con- your creative talents to solve. If you've been wondering what explains in detail how you can de- struction and programming. The all the hoopla about PASCAL is sign and build your own terminal Since the video system in this chapter winds down with informa- then this is the book for you. Since for less than $20! book is based around the 650x tion concerning modifications and you'll probably be seeing a lot of microprocessors, it is necessary part of a chess program utilizing The big secret behind cheap PASCAL anyway, what with the that you be familiar with the 6500 the color-graphics module. video is that there is relatively little Apple II, TRS-80 and other ver- machines as well as the KIM-1. hardware used—a handful of The principles of transparency, sions coming out, you may as well The author recommends that prior gates and a character generator. which allow' the CPU to compute buy the book now and save your- to this book you read the follow- The key to the system is the micro- data and run the video interface self some time later. processor. Utilizing several rou- ing: The TV Typewriter Cook- simultaneously, are discussed in You can probably already tell tines in conjunction with a video book (Sams 21313); An Intro- chapter 5. Several methods are that 1 like this book. As a matter interface, the microprocessor does duction to Microcomputers, shown along with the 6500 soft- of fact, I can't say enough good all the "housework" such as Volumes I & II (Osborne 2001 and ware required to make them work. things about it. If we'd had text- generating the video and sync 3001, respectively); user's manuals books like this when I was in signals. By changing your soft- for the 6500 and KIM-1; user's Four appendices finish the school, we wouldn't have needed ware structure, you can change manuals for your system. book. Appendix A is simply a list- teachers. Grogono takes you by your terminal's characteristics. As ing of the ASCII code, while ap- Obviously, The Cheap Video the hand and leads you through a result, you can have a very sim- pendix B is an octal-hex-decimal Cookbook is not intended for the the very most fundamental con- ple terminal or a very versatile one conversion chart (rather handy!). beginning hobbyist. cepts of programming through the with almost any feature you could Appendix C contains the pin-outs The Cheap Video Cookbook most powerful features of want. Features include: any dis- of several ICs used throughout the contains five chapters. Chapter 1 PASCAL. The text is liberally il play format from 1 x 16 to 24 x circuits described in this book. deals with the foundations of lustrated with actual programs 80; various character fonts from 5 Appendix D repeats the PC board cheap video, how it works, w hat it and easy-to-understand syntax x 7 dot matrix to Old English; 256 patterns scattered in chapter 4. can do and which CPU to use. diagrams (finally—easy-to-read x 256 black and white graphics; Two new and very important con- Overall, the book appealed to syntax diagrams!) that make 96 x 128 color graphics; a host of cepts are also introduced: the Scan me. The material is presented in a learning the language a snap. control features such as scrolling Microinstruction and the Up- clear, easy-to-understand manner and reversed video. stream Tap. (provided, of course, you have the Chapter 1, an introduction to computer programming, includes Chapter 2 shows how to design necessary background material The important thing to notice is a discussion of what a program is the software for the cheap video previously mentioned) and can be that no matter how advanced a and a short introduction to system. Here we discover how to mastered in a fairly short time. My terminal you want, the price you PASCAL to help you get your feet build programs for the scan micro- biggest complaint is that the soft- pay for an extra option is not an- wet. I have a strong feeling that instruction, alphanumeric dis ware and most of the hardware is other fancy 1C, but rather another even a non-programmer can learn plays, high-resolution graphics designed primarily for the 6500 portion of your memory. And you to write PASCAL programs with and full-performance cursors. series CPUs. don't need much memory either; no help but this book. Chapter 1 is Editors and graphics loaders are Although I believe that every IK will keep you busy for quite a part of the reason for this. while. also described in detail. Inci- computer system can be adapted dentally, owners of KIM-1 sys to use cheap video techniques in Chapters 2, 3 and 4 cover much While the video system de of the language. With these first scribed in this book has a lot going tems will be able to use these pro some way, I don't recommend this grams right out of the book. book to anyone who doesn't own four chapters under your belt for it (low cost and versatility), it you'll be ready to try some pro- Chapter 3 involves the design of a 6500 or 6800 microcomputer. also has a few disadvantages. The grams of your own. The clarity of the video interface. The circuit is However, if you do own another most serious one, perhaps, is that the book and the well-chosen ex- designed step-by-step from the in- type of system and are sincerely in- it will not readily work with many amples should make these about a struction decoding PROMs to the terested in a $20 video terminal CPUs. The CPU must meet cer- weekend's worth of reading even output circuitry. Finally, you are and you are willing to put much tain demands if the video interface for a total beginner. is to function properly. One re- shown how to interface the system time and effort into it, then I sug- Chapter 5 covers some of the quirement is that the microproces- with a KIM-1 and how to add a gest you either borrow a copy or functions PASCAL performs sor be able to advance the program video input to an ordinary TV set. read the first chapter in the book- store before you purchase the counter once every microsecond Chapter 4 is like an instruction book. That way you can determine It must also have 16 always-pres- booklet for the many electronic (see REVIEWS, page 14) •MO SHEHTIRB'S .... SMALL SYSTEMS JOURNAL

Introduction

Our objective in this issue is to give the reader brief descriptions of two systems included in the OS-DMS grouping—General Ledger and Payroll—which have not yet been shown in our previous articles. Several of the reports created by these systems will be shown in order that the reader might better understand the purposes of the systems

OS-DMS General Ledger System In the normal office environment there is a need to keep track of how much business is done by the firm. Whether the amounts earned are normal or not and whether the company is making a profitable return on its investments are samples of questions constantly posed about a business. The figures utilized to answer these questions are measurements of money, and the process of working with these figures is called accounting. The most basic accounting report used in the process of keeping track of a firm's activities is the general ledger, and any specific series of operations designed to reveal the financial status of a firm is called a general ledger system. A general ledger system may be manual or automated. It may be very simple for a small firm or extremely complex for a large corporation with multiple divisions or departments. In all cases, however, the basic objectives of having a general ledger are the same: enable I an«*'INc| | I.LWtl I CHa*T oil I (.1 msti I KuimsJ I Mill I ftCCOWIsJ | UW I management to know how the firm is faring financially as well as make decisions and forecasts from an informed position. The OS-DMS General Ledger System is designed to fit into this office environment in the FIGURE I OS-DMS GENERAL LEDGER LOGIC FLOW DIAGRAM following manner. Cash is earned or borrowed, spent or loaned, and in other ways comes and goes. This The first area we shall look at is the input function This general ledger system has tv cash flow should be carefully controlled. This is the objective of the cash receipts and specific input routines—one to handle cash receipts and disbursements and the other disbursements portion of this system. All incoming and outgoing funds are entered in detail work with all other types of entries. The main difference between the two is that the form on the computer through the console terminal in a clerical operation. The payer or payee creates a detailed transaction file of all entries, whereas the latter posts directly to tl name, the date, a reference number of some type, a general ledger account number and the general ledger master file. Sample input journals are as follows: dollar amount of each activity are put into the computer as the transactions take place. An input journal of the events that take place in this operation is printed so that the person overseeing the cash flow (the manager) may review the activities when the need arises. Periodically, cash receipts journals and cash disbursements journals are printed in order to CASH RECEIPTS OR DISBURSEMENTS INPUT jOURNAL 01 26/79 have records of the cash activities of the firm. At the ends of accounting periods, totals from each general ledger account affected by the cash flow from the period are posted to PAYER, PAYEE DATE ACCT • the general ledger, and the cash books for that period are closed. STARTING NEW ACCOUNTING PERIOD While cash transactions make up a large activity area in business, many accounting en- SUBTOTAL 0 00 tries do not include a movement of funds. Buildings and equipment must be depreciated. Items are bought and sold for promises to pay. Taxes and other expenses are accrued ADD RECORDS through a certain date. All these entries must appear in the company's books . . . CASH RECEIPTS . . . In this general ledger system, these types of transactions are entered separately from the IOHNSON BAKERY 01/03/79 203756 1020 250 ( r ( cash movements. The routine through which these entries are made prints the general jou - SMITH LUMBER CO 01 05 79 33398 4010 1 59. nal. a normal accounting entry ledger Through this general journal, records are maintained APEX STORES INC 01/10/79 12205 1020 500 ( as to what activity has gone on at what time. CONSOLIDATED TRUST 0110/79 330856 4010 3579 ! The data entry is constant in both the cash and non-cash areas. The end of an accounting JACKSON DRUGS 01 12 79 222556 1020 3001 period is a point at which the entries for one measurable time period—usually a month or a W1W CAFETERIA 01/15/79 330564 1020 325 ! year—are stopped so that their contents may be worked with, totaled, compared to other CITY FINANCE CO 01 17/79 440322 4010 1399.! like periods and evaluated. This is the closing of the books. Reports such as the general SUBTOTAL: 6514 51 ledger, the operating statement and the balance sheet are printed for middle and upper management's needs. Data is stored for historical reference and analysis. Management per- sonnel now have reports concerning a standard time period in a common format with which ADD RECORDS they may make decisions that affect the future of the firm. ... CASH DISBURSEMENTS . FIRST NATIONAL BANK 01/110/7 9 44032 2015 115 1 This system produces all the reports mentioned above. It also takes care of expansion or WILLIAMS EQUIPMENT 01 12/79 22034 5010 304 restructure of the general ledger system. Protection of the data through disk backup is an ACME INSURANCE CO 01/ 15/79 33944 5250 157.1 integral part of this operation. OfFICE PAYROLL 01 15/79 22045 5410 3022 ! The OS-DMS general ledger is open-ended. Though this system is large, and in itself is SUBTOTAL: 3599.29 complete, it is just a part of the needed product for most users. Through the use of the various other modules and the nucleus utilities of OS-DMS. there is much that may be done to expand its capabilities. Every user s needs are different, so this is a necessary state. It is ... END RUN . . . felt that the base provided here can support this expansion. FIGURE 2 CASH RECEIPTS OR DISBURSEMENTS INPUT jOURNAL GENERAL IOURNAL 1/23/79 9:46 OPERATING EXPENSES SALES EXPENSES DATE ACCT NAME DESCRIPTION REF NUMBER DEBITS CREDITS SALES SALARIES , 2053 69 1 1.21 19858 55 1 1.99 I 10/79 1030 IOHNSON EQUIPMENT 33085 2579 40 ADVERTISING \ 359 98 1.97 3476 18 2.10 1/10/79 2010 ACCOUNTS PAYABLE 33085 2579 40 TOTAL SALES EXPENSES 2413.67 13.18 23334 73 14 09 1/10/79 1040 HAYES OFFICE SUPS 33057 13.78 GENERAL EXPENSES 1 10/79 2010 ACCOUNTS PAYABLE 33057 13.78 SALARIES 684 30 3 74 6615 50 4 00 1/13/79 1330 GLOVER SUPPLY CO 33058 308.00 RENT 152.55 .83 1476 21 89 1/13/79 2010 ACCOUNTS PAYABLE 33058 308 00 TELEPHONE 392.23 2.14 4070 63 2 46 TOTAL GENERAL EXPENSES 1229.08 6.71 12162 34 7.35 1/16/79 4010 ALLIED STORES 55098 4500 00 1 16 79 1020 ACCOUNTS RECEIV 55098 4500 00 TOTAL OPERATING EXPENSES 3642 75 19 89 35497.07 21 44 1/16/79 1020 55098 CORRECTION 55098-C 4500 00 NET PROFIT—LOSS 6635.29 36.23 1898331 1 1.47 1 16/79 4010 55098 CORRECTION 55098-C 4500 00 1/18/79 1030 ALLIED STORES 55098 4500 00 FIGURE 5 OPERATING STATEMENT 1/1879 4010 SALES 55098 4500 00

Other reports necessary for the smooth operation of a general ledger system are the utility TOTALS: 16401 18 16401 18 reports. Included in this category are printouts such as a chart of accounts and a formatted NET 0.00 master file listing In the OS-DMS system, these two reports appear as follows FIGURE 3 INPUT GENERAL IOURNAL In addition to the printouts from these input runs, we should also look at the end-of-period statements. The first of these is the balance sheet, and the standard OS-DMS format is as CHART OF ACCOUNTS 9/30 78 follows:

BALANCE SHEET ACCT « DESCRIPTION DEBIT CREDIT FOR PERIOD ENDING 9/30/78 ASSETS CURRENT ASSETS 1020 CASH ASSET DEBIT ASSETS 1030 ACCOUNTS RECEIV CURRENT ASSETS ASSET DEBIT 1040 INVENTORY ASSET DEBIT CASH 8591 99 1050 PETTY CASH ASSET DEBIT ACCOUNTS RECEIVABLE 6572 76 TOTAL CURR ASSETS MINOR TOTAL INVENTORY 4502 78 PETTY CASH 753.83 FIXED ASSETS 1510 LAND TOTAL CURR ASSETS ASSET DEBIT 1520 BUILDINGS ASSET DEBIT FIXED ASSETS 1530 DEPRE—BUILDINGS ASSET CREDIT LAND 12301 38 1540 EQUIPMENT ASSET DEBIT BUILDINGS 51348 55 1550 DEPRE—EQUIPMENT ASSET -9417 67 CREDIT DEPRECIATION—BUILDINGS TOTAL FIXED ASSETS EQUIPMENT 10753 20 -4301 75 OTHER ASSETS MINOR TOTAL DEPRECIATION—EQUIPMENT 1810 PREPAID DEPOSITS TOTAL FIXED ASSETS TOTAL OTHER ASSETS ASSET DTHER ASSETS TOTAL ASSETS PREPAID DEPOSITS MINOR TOTAL TOTAL OTHER ASSETS LIABILITIES MA|OR TOTAL TOTAL ASSETS 81633.63 CURRENT LIABILITIES -I ABILITIES 2020 ACCOUNTS PAYABLE LIABILITY CREDIT 2URRENT LIABILITIES 2030 DIVIDENDS PAYABLE LIABILITY CREDIT 2040 INCOME TAX PAY LIABILITY ACCOUNTS PAYABLE 3419 82 CREDIT 2050 INTEREST PAYABLE LIABILITY CREDIT DIVIDENDS PAYABLE 4106 09 2060 INSURANCE PAYABLE LIABILITY CREDIT INCOME TAX PAYABLE 1821.69 FIGURE 6 PORTION OF CHART OF ACCOUNTS INTEREST PAYABLE 532 43 INSURANCE PAYABLE 378 66 TOTAL CURR LIABILITIES OS-DMS GENERAL LEDGER MASTER FILE LISTING 9 30 78 ONG-TERM LIABILITIES LONG-TERM NOTE ACCT # DESCRIPTION PREV BAL TRNSACTNS TOTAL LONG-TERM LIABS 1000 ASSETS )THER LIABILITIES 1010 CURRENT ASSETS PREPAID SERVICES 1020 CASH 6270 46 2321 53 TOTAL OTHER LIABILITIES 1030 ACCOUNTS RECEIVABLE 7191 22 -618 46 TOTAL LIABILITIES 1040 INVENTORY 2503 48 1508 30 TOCKHOLDERS EQUITY 1050 PETTY CASH 778 40 -24 57 COMMON STOCK 1499 TOTAL CURR ASSETS 40000 00 1500 FIXED ASSETS RETAINED EARNINGS 18983 31 TOTAL STKHOLDERS' EQUITY 1510 LAND 12301 38 0 00 TOT LIABILITIES S. EQUITY 1520 BUILDINGS 51348 55 000 1530 DEPRECIATION—BUILDINGS -8692.23 -725 44 1540 EQUIPMENT 10753.20 0 00 IGURE 4 BALANCE SHEET 1550 DEPRECIATION—EQUIPMENT - 3980 66 -321 09 1799 TOTAL FIXED ASSETS Jong with the balance sheet, the other primary end-of-p«riod report is the operating state- 1800 OTHER ASSETS lent. often referred to as a profit and loss statement. The standard OS-DMS operating 1810 PREPAID DEPOSITS 507 21 21 35 ratement has the following format:

OPERATING STATEMENT CURR BAL RCD TYPE DEBIT CREDIT SOURCE OPEN I OPEN 2 FOR PERIOD ENDING 9 30/78 H (HEADER) H (HEADER) CURR % CURR YTD % YTD 8591.99 A (ASSET) 3W CASH ESCRIPTION AMOUNT SLS AMOUNT SLS 6572.76 A (ASSET) 4E A/R EVENUES 4502 78 A (ASSET) 25 INV ALES 18509 10 101.06 167705 43 101 29 753.83 A (ASSET) 7T 0 ALES RETURNS 194.35 1.06 2142 56 1.29 3 (MINOR TOT) NET SALES 18314.75 100 00 165562.87 100 00 H (HEADER) OST OF SALES 12301.38 A (ASSET) M 51348.55 A (ASSET) M BEGINNING INVENTORY 1508 30 8 24 2503.48 1.51 -9417.67 A (ASSET) M ADD: PURCHASES 10210 44 55.75 103750 54 62.67 10753 20 A (ASSET) M DED: PURCH RETS S. ALLOWS 820 75 4 48 9331 25 5.64 -4301.75 A (ASSET) M TOTAL GOOD AVAIL 12539 49 68 47 1 15585 27 69.81 3 (MINOR TOT) EDUCT: ENDING INVENTORY 4502.78 24 59 4502 78 2.72 H (HEADER) TOTAL COST OF SALES 8036.7 1 43 88 111082 49 67.09 528 56 A (ASSET) M ROSS PROFIT 10278 04 56.12 54480 38 32.91 FIGURE 7 PART OF GENERAL LEDGER MASTER FILE LISTING

OHIO SCIENTIFIC 1333 S. Chillicothe Road • Aurora, Ohio 44202 • (216) 562-3101

* Reader Service—see page 227 Microcomputing, October 1979 11 In addition to the reports shown above, of course, there is some form of printed documen- POSSIBLE DEDUCTIONS tation created by practically every operation performed within the system. This Is designed I FICA 2 FEDERAL INCOME TAX to assist the user in recording his actions, but even more, to allow him to see where he has 3 STATE INCOME TAX 4 LOCAL TAX skipped an operation. In all cases, the objective of the system has been to assist the user In 5 INSURANCE 6 OTHER DEDUCTIONS the management of his firm and give him belter control SELECT DEDUCTIONS FICA IS THIS DEDUCTION TO BE USED ? OS-DMS Personnel/Payroll System FEDERAL INCOME TAX IS THIS DEDUCTION TO BE USED ? Payroll is a normal part of any business that employs more than one person. In order to STATE INCOME TAX comply with various laws, an employer must maintain records of each payroll run made for IS THIS DEDUCTION TO BE USED ? N the firm In response to this need. Ohio Scientific has developed the Personnel Payroll LOCAL TAX System under OS-DMS. IS THIS DEDUCTION TO BE USED ? N The programs in this computerized system allow the operator to perform three basic per- INSURANCE sonnel functions. The first is to compile and maintain an accurate employee data file, the IS THIS DEDUCTION TO BE USED ? N second is to generate reports from this data, and the third is to run payroll. OTHER DEDUCTIONS The various primary options available in this system are as follows: IS THIS DEDUCTION TO BE USED ? Y ENTER THE AMOUNT Of THE EMPLOYEE DEDUCTION ? 50 00 PERSONNEL AND PAYROLL SYSTEM FIGURE I I EMPLOYEE DEDUCTION CHANGE

(1) INSTRUCTIONS (2) EMPLOYEE EARNINGS REPORT (3) CHECK FILE REPORTS At the end of the run the totals for the entire payroll run are made. These are needed f (4) PAYROLL FOR ALL ACTIVE EMPLOYEES several reasons, most importantly to insure that the amount of money being paid out (5) PAYROLL FOR INDIVIDUAL EMPLOYEES known and can be deposited in the payroll bank account to cover the checks being issue (6) EDIT PAYROLL INFORMATION (7) EDIT EMPLOYEE INFORMATION (8) EDIT CHECK FILE INFORMATION (9) SORT PAYROLL INFORMATION (10) SORT EMPLOYEE INFORMATION PAYROLL FOR 7 3 79 TODAYSDATE: 7 20 79 (99) EXIT FIGURE 8 PERSONNEL PAYROLL MENU TOTAL NUMBER OF EMPLOYEES PAID 4 AVERAGE OVERTIME HOURS I 86 TOTAL REGULAR PAY 1749 35 From the menu above, the various options available to the operator may be described as TOTAL OVERTIME PAY 51 74 follows: TOTAL COMMISSIONS 0.00 Option I presents to the operator a series of instructions as to how to run the system prop- TOTAL OTHER PAY 0 00 erly. TOTAL GROSS PAY Options 2 through 5 are covered in detail following this explanation. Options 6 through 10 TOTAL FICA 1 10 40 are file maintenance operations used to put new employees on the file, change the informa- TOTAL FEDERAL 228.58 tion in their records when needed and sort their records in various sequences as the occa- TOTAL STATE 15.97 sions warrant These runs, while not the producers of the end product, are used with TOTAL LOCAL 18.02 regularity to maintain the various files. Options 4 and 5 perform the same operations with TOTAL INSURANCE 37.50 one primary difference: the payroll run for an individual does not update the computer files. TOTAL OTHER DEDUC 0 00 When an out-of-cycle check is run for an employee, then the editing programs should later TOTAL DEDUCTIONS 410 47 be used to enter the data into his records. TOTAL NET PAY 1390 62 The sequence of operations for all payroll runs starts with the presentation to the operator of the run options. These are shown on the monitor screen and set the pattern for the entire FIGURE 12 PAYROLL SUMMARY run Following this, the entries for the individual employees are made The computer gets these through a dialogue with the operator as shown below

EMPLOYEE NAME ALCORN ALAN EMPLOYEE NUMBER 0 WAGE EMPLOYEE When all the entries have been made and the totals printed, the check stubs may be print) for the employees. A variation of this run is to have the computer print the actual checl- « NO COMMISSIONS » but since check designs vary significantly from company to company, the actual che REGULAR HOURS WORKED ? 80 printing program is riot included as a part of the system. OVERTIME HOURS WORKED ? 2 3 OTHER PAY ? I 23. I I FIGURE 9 EMPLOYEE HOURS ENTRY For filing purposes, the payroll register is printed and is then available for historical us<

With the information now known, the calculations of the individual's payroll figures are made and the following display of the results is made on the monitor screen:

EMPLOYEE NAME: ALCORN ALAN CHECK FILE REPORT FOR THE 7 3 79 PAYROLL TODAY'S DATE: 7 29 79 PAGE EMPLOYEE NUMBER: 0 WAGE EMPLOYEE

REGULAR PAY 400 00 OHIO SCIENTIFIC 7/3/79 OHIO SCIENTIFIC 7/3/79 OVERTIME PAY 17 25 NAME: ALCORN ALAN NAME: BEACHLY jERRY COMMISSION: 0 00 REGULAR HRS. 73.75 REGULAR HRS 80.00 OTHER PAY 123 22 GROSS PAY: 540 47 OVERTIME HRS 2 50 OVERTIME HRS 32 DEDUCTIONS PAY RATE 5 00 PAY RATE 3 75 FICA 33.13 REGULAR PAY: 368 75 REGULAR PAY: 300 00 FEDERAL INCOME TAX 79 51 OVERTIME PAY: 18.75 OVERTIME PAY: 1 80 STATE INCOME TAX 6 01 COMMISSIONS: 0 00 COMMISSIONS 0.00 LOCAL TAX 5 40 OTHER PAY: 0 00 OTHER PAY: 0 00 INSURANCE 7 50 GROSSPAY 387 50 GROSS PAY 301 80 GROSS DEDUCTIONS 131.55 NET PAY 408 92 DEDUCTIONS DEDUCTIONS IS THIS CORRECT > N FICA: 23.75 FICA: 18.50 (1) EARNINGS CHANGE (COMPLETE CHANGE) FEDERAL: 48 33 FEDERAL: 32.90 (2) DEDUCTION CHANGE STATE: 2 95 STATE: 2.05 (3) SKIP THIS PERSON LOCAL: 3 88 LOCAL: 3.02 ? 2 INSURANCE: 7 50 INSURANCE: 0.00 FIGURE 10 EMPLOYEE PAYROLL CALCULATIONS VERIFICATION MISC: 000 MISC: 0 00

If the employee deduction change is desired, the following series of questions and answers takes place between the operator and the computer OHIO SCIENTIFIC 7/3/79 When ends of reporting periods pass, various reports are required for numerous govern- NAME: CALOWAY |OHN mental agencies as well as the firm s own needs To provide the data necessary for the pro- duction of these reports, the employee earnings record Is often used. This report prints all REGULAR HRS 80 00 payroll information about a given employee or about all employees for whatever payroll or OVERTIME HRS 0 00 group of payrolls is specified at the start of the program It is formatted as follows: PAY RATE 733 83

REGULAR PAY: 733 83 OVERTIME PAY: 0 00 COMMISSIONS: 0 00 OTHER PAY: 0 00 733 83 GROSSPAY NAME: |OHN DOE ADDRESS: I 234 SOUTH LAKE STREET DEDUCTIONS KENT. OH 44240 FICA: 44.98 PHONE: 898-1 121 FEDERAL: 87 90 OVT TOTAL PAY REG OVT STATE: 8 15 PERIOD REG HRS RATE PAY PAY LOCAL: 7 34 ENDING HRS HRS INSURANCE: 22 50 57 00 0.00 57 00 0 00 456 00 0 00 MISC: 0 00 1/2/79 1/16/79 87 75 0 00 87 75 8 00 702 00 0 00 0 00 73 00 8 00 584 00 0.00 TOTAL DEDUCTIONS 170.87 1/30/79 73.00 0 00 82 00 8 00 656 00 0 00 NET PAY 562 96 2/13/79 82 00 2/27/79 86 50 0.00 86.50 8 00 692.00 0 00 0.00 88 50 8 00 708 00 0 00 FIGURE 13 CHECK STUBS 3/13/79 88 50 3/27/79 70 00 0.00 70 00 8 00 560 00 0 00 4/10/79 76 50 0 00 76 50 8 00 612 00 0 00 4/24/79 85 00 0.00 85 00 8 00 680 00 0 00 5 8/79 83 50 0.00 83 50 8 00 668 00 0 00 5/22/79 86 50 0 00 86 50 8 00 692 00 0 00 ten FIU REPORT FOR THE 7 3 79 PAYROLL TOOAY'S DATE: 7 29 79 6/5/79 129 25 0 00 129 25 8 00 1034 00 0.00 6/19/79 80 00 0.00 80 00 8 40 672 00 000 iME ALCORN ALAN 7/3/79 86 00 0 00 86 00 8 40 722 40 0 00 EG HRS 73 75 REG PAY 368 75 FICA 23 75 IVT MRS: 2 5 OVT PAY 18 75 FEDERAL 48 33 COM PAY 0 STATE 2 95 TOTALS FOR THE PERIOD OTHER PAY 0 LOCAL 3 88 INSURANCE 7 5 REG HRS : I 171 SO REG. PAY: 9438 40 OTHER 0 OVT HRS: 0 00 OVT. PAY: 0.00 COM. PAY: 0 00 387 50 GROSS DEDUC 8641 NET PAY 301 09 OTHER PAY: 466.02 iME BEACHLY |ERRY EG HRS 80 REG PAY. 300 FICA: 18 5 GROSS PAY: 9904 42 IVT HRS 32 OVT PAY 1 8 FEDERAL 32 9 COM PAY 0 STATE: 2 05 .Y RATE: 3 75 OTHER PAY. 0 LOCAL: 3 02 INSURANCE 0 OTHER 0

GROSS PAY: 301 80 GROSS DEDUC 56 47 NET PAY: 245 33

LMECALOWAY |OHN EMPLOYEE EARNING RECORD [EG HRS 80 REG PAY 733 83 FICA 44 98 TVT HRS 0 OVTPAY 0 FEDERAL: 87 9 SOCIAL SECURITY NUMBER III 12-2222 COM PAY: 0 STATE: 8 15 DATE HIRED I 4 74 7 34 :Y RATE: 733 83 OTHER PAY: 0 LOCAL DATE TERMINATED MARITAL STATUS SINGLE INSURANCE 22 5 ALLOWANCES I OTHER 0 OCCUPATION ASSEMBLER

GROSS PAY: 733 83 GROSS E7EDUC 170 87 NET PAY: 562 96 OTHER GROSS FICA FED STATE LOCAL OTHER GROSS NET PAY PAY W.T W T W T W T. W.T DEDUC PAY LME SMITH SANDY [EG HRS: 77 06 REG PAY 346 77 FICA: 23 17 3 82 4 56 0 00 106 32 349 68 )VT HRS: 4 62 OVTPAY 3119 FEDERAL: 59 45 0 00 456 00 27 59 70 35 COM PAY: 0 STATE: 2 82 1 14 54 816 54 50 05 181 65 12.19 8 1 7 0 00 252 06 564 48 3 78 lY RATE: 4 5 OTHER PAY 0 LOCAL 0 00 584 00 35 80 102 97 6 38 5 84 0 00 1 50 99 433 01 INSURANCE 7 5 59 29 7 I 5.29 43 85 143 05 9 56 7 15 7 50 21 It 1 504 18 OTHER 0 0 00 692 00 42 42 1 34 70 8 98 6 92 7 50 200 52 491 48 GROSS PAY. 377 96 GROSS DEDUC 96 72 NET PAY 281 24 107 81 815 81 50 01 1 76 46 12.17 8 16 7 50 254 30 561 51 0 00 560 00 34 33 96 08 5 90 5 60 0 00 141 91 418.09 0 00 612 00 37 52 1 10 70 6 98 6 12 7 50 168 82 443 18 C.URE 14 PAYROLL REGISTER 89 18 769 18 47 15 160 60 10 91 7 69 7 50 233 85 535 33 0 00 668 00 40 95 127 50 8 38 6 68 7 50 191 01 476 99 14 71 706 71 43 32 139 37 9 35 7 07 7 50 206.61 500 10 nother format used for saving and filing the information is that used for the earnings and 0 00 1034 00 63 38 255 70 12 90 10 34 7 50 349 82 684 18 Ktuctions summaries If there are few types of earnings and deductions, these two may be 80 49 752 49 46 13 1 54 93 10 49 7 52 7 50 226 57 525 92 ^mbined as a single report. 0 00 722 40 44 28 144 70 9 74 7 22 7 50 213 44 508 96

FICA W T 606 78 FEDERAL W T 1998 76 AYROLL SUMMARY FOR 7 3 79 TODAY'S DATE: 7 29 79 STATE W.T : 127 75 LOCAL W T : 99 04 IAME REG HRS OVT HRS PAY RATE REG PAY OVT PAY COM OTHER OTHER W T : 75 00

,LCORN ALAN 73 75 2 5 5 368 75 18.75 0 0 EACHLY |ERRY 80 32 3 75 300 1.8 0 0 GROSS DEDUCTIONS 2907 33 NET PAY: 6997 09 ALOWAY |OHN 80 0 733 83 733 83 0 0 0 MITH SANDY 77.06 4 62 4 5 346 77 3119 0 0 FIGURE 16 EMPLOYEE EARNINGS RECORD AYROLL SUMMARY FOR 7/3/79 TODAY' S DATE: 7 29/79 PAGE: 2

IAME FICA FEDERAL STATE LOCAL INSURANCE OTHER

ALCORN ALAN 23 75 48 33 2.95 3 88 7.5 0 IEACHLY |ERRY 18 5 32 9 2 05 3 02 0 0 The next issue will conclude our series of articles on OS-DMS with a discussion of the new :ALOWAY IOHN 44 98 87 9 8 15 7 34 22 5 0 Educational Testing System. Quotation/Estimation System and the enhanced Inventory ,MITH SANDY 23 17 59 45 2 82 3.78 7.5 0 System including order entry, inventory explosion and forecasting. IGURE 15 EARNINGS AND DEDUCTIONS SUMMARIES

OHIO SCIENTIFIC 1333 S. Chillicothe Road • Aurora, Ohio 44202 • (216)562-3101 puter-science major, I feel that an are, of course, under control of and the most accurate advice. Un- introductory book like this should the operating system, and are in- fortunately, this book contains REVIEWS make no assumptions about the variably quite flexible. almost none. The chapter on soft- reader's background. A program- I am not trying to nitpick. I ware lists computer languages (from page 9) ming text not directed toward em- want to make it plain that these are without explaining their features bryonic engineers w ill be welcome. only a couple of examples of the or intended uses. It ignores the such as CASH statement, scalars, Maybe someday I'll write my own. abysmal lack of technical expertise subject of application programs, subranges and sets. Chapter 6 in- William L. Colsher displayed by the authors— which which is of paramount importance troduces arrays and records; chap- Lisle IL makes their poor attempts to ex- to the business user. ter 7 presents files. Titled plain technology to the naive In summary, the writers have "Dynamic Data Structures," reader a real imposition on his tried to cover an incredibly be- chapter 8 covers pointers and valuable time and a waste of his wildering array of technical topics linked lists in one of the most lucid $15.95. And they don't know in a book intended to be a guide to treatments I've ever seen. Chapter Computer Power for the when to quit, roaming far afield selecting a business computer. 9 finishes up the language with the Small Business from the subject of business com- And they do cover these topics— GOTO statement and some dis- Charles J. Sippl, Fred Dahl puters to discuss everything from with an impenetrable rubble of un- cussion of dynamic memory allo- Prentice-Hall, Inc. microphones to robots, in great necessary definitions and technical cation. Englewood Cliffs NJ detail and with gross inaccuracy. inaccuracies, preventing the busi- As soon as you have some grasp 1979, $15.95 I never knew that those funny nessman from finding what little of the language, you can read little bar codes on packages in the good advice the book does con- chapter 10, which covers program This book is full of words. Vir- grocery store are what is known as tain. But the silly advice over- design. This is handy for the be- tually all of them are arranged into the "Universal Produce Code." whelms the good . . . for in- ginner who may not have any idea grammatically correct sentences. Just try to stick one on a head of stance, the suggestion that the at all how to go about developing, Virtually none of these sentences lettuce! businessman should read such testing and debugging a program. can convey any useful information publications as "Digital Design," Moving on to the subject of the For the non-programmer who to the intended reader, the small which is exactly what its name im- requirements for a business com- wants to learn how, this chapter businessman. plies, a periodical for digital-de- puter, the picture caption on page alone is worth the price of the If we may begin with a sum- sign engineers. 77 opens with the statement that book. Appendix D, "Program mary, this is the worst "technical" "RCA's Cosmac VIP is certainly One accurate statement that the Standards," should be read along book I have ever seen. The writers applicable to business uses . . . ." book does contain is that the book with this chapter for a good don't understand the technology The photo shows a gentlemen la- itself (ignoring pictures) "could understanding of what makes a they attempt to report on (in much boriously keying in what appears easily be contained on a single program a good or bad piece of too much detail); they don't un- to be a multiple-page program floppy diskette." Perhaps the work. derstand the requirements for through the VIP's tiny keypad. book should be on a floppy. It business computing; and there is A section of the book simply Now, the VIP is a fine little ma- would make it easier to return it to no way that their intended reader, titled "Further Reading," with no chine as far as it goes, and it can be the seller. And it should be re- the small-business "operator" chapter or appendix number, is a used as an introduction to micros; turned, on the grounds that it is (their term), could get past the boon to somebody like me who as the basis on which to build a not at all what it is advertised to flood of meaningless (to him) knew absolutely nothing about hobby computer; or as a toy. But a be: "a complete and practical technical detail to what little good PASCAL before he picked up this business computer it certainly is guide" to selecting and using a advice the book contains. book. This section contains a good not! business computer. PASCAL bibliography along with To support these contentions, But save the return postage. information on the PASCAL The writers just don't seem to let's look at the authors' reporting Don't buy this book. Users' Group. Used in conjunc- know what computing or data of computer technology. "A One final, ironic quote from tion with your local college storage a business requires. Hence 12-inch rectangular CRT usually Sippl and Dahl: "Something is library, this section w ill easily take their statement that "a year's displays 32 characters in 8 lines." missing in the business computer care of your spare time for about a worth of records can very likely be (Emphasis mine.) Now, they are market: knowledgeability." They month. supposed to be talking about contained on—at most—two flop- pies." Did they ever interview provide a prime example of the Appendices A and B cover, in business computers, including anyone using a computer in busi- truth of that statement! summary, the vocabulary and syn- micros, but that description fits ness? What research led to this as- Ken Barbier tax of PASCAL. The syntax ap- the crudest of TV games at best. tounding conclusion? A year's Borrego Springs CA pendix (B) contains all those "Usually?" worth of records for an entire marvelous syntax diagrams that "The standard floppy is 9 inch- small business on two floppies? It are spread throughout the text. es square." (The italics are theirs would seem to be a wonderful I've copied mine and have them this time, saving me the trouble!) dream. Maybe it was. pinned to the wall in front of my If floppies were nine inches on a Logic—Home Study Course desk for quick reference while I'm side they would loose one of their Similarly detached from reality Milton Howard Aronson still learning PASCAL. Appendix finest attributes: the ability to be is the statement, in the context of Measurement & Control C, the last of the appendices, can shoved into a "standard" file discussing the smallest ($2000) sys- Pittsburgh PA be safely ignored unless you hap- folder in a "standard" file tems, that software costs "can be 32 pages. Paperback, $3 pen to be using the CDC imple- cabinet. It makes me wonder if the as much as half the cost of the mentation of PASCAL. It con- authors ever saw a floppy, or a hardware." This statement ap- If you are in any way mixed up tains a discussion of the peculiar- ruler. pears to be based on a single exam- with computers or logic devices, ple of a system used to control an ities of that implementation and is While on the subject of flop- you probably should have this air-conditioning system—not a rather interesting, but probably pies, the writers warn the reader to course. The course is actually a business computer as such. It is of- not much use to most readers of be on the lookout for "t>refor- "home study" article reprinted fered to a reader contemplating the book. matted" floppies, which they in- from the September-October 1970 the purchase of a business com- After raving about the book for sist means "hard-sectored." (Just issue of the trade magazine Medi- puter as advice on what to expect eight paragraphs I have to register the opposite is the case, of course.) cal Electronics and Data. It be- his software to cost. At best it is a my one complaint. Virtually all Their warning is ridiculous to gins by explaining what logic is gross underestimate. the examples in the early part of begin with, as they claim that Pre- and what it does. Assuming no the book are mathematical. So are formatting will force the user to It is in the field of business soft- particular background in either the exercises at the end of the adapt his file size to that required ware that the prospective com- chapters. Despite being a com- by the Preformatting. File sizes puter user needs the most advice, (see REVIEWS, page 108) ttitm I isiusiBinr Secretary, Fred Waters which has data file capability, as STRINGY FLOPPY FOR SWTP well as compatibility with Micro- soft BASICs on other machines. This month the newsletter of EDIT loads the TSC Text Editor, the Exatron Stringy Floppy an excellent line- and content- Owners Association (ESFOA for oriented editor with many local short) addresses the SWTP ver- and global commands. ASMB sion. in keeping with the theme runs the TSC Assembler, a fast of this issue. mnemonic assembler with object If you haven't taken a close code generation into memory or JIM MA YNARD WORKING ON SOFTWARE FOR THE SS 50 ESF look at the front cover, do it into a Stringy Floppy. now. You can see that the Exa- Other system commands in- NOW HEAR THIS! Membership in the ESI OA is automatic when tron Stringy Floppy is capable clude HSAVE, HLOAD. NEW- you purchase an Exatron Stringy Floppy. One of the purposes of of earning a living at the office TAPE, and ASN. For a system this Newsletter is to tell you about some of the interesting and useful as well as in the more traditional having one drive, no drive num- projects which have been completed by ESIOA members. Jim May- role as "Keeper of the Games". ber is specified in the command. nard, an expert programmer and hardware designer, has spent many This exciting new subsystem con- If you have a two-drive system, many hours during the past year developing the SS-50 version of the sists of a controller and up to you specify the drive number if ESF. Jim accomplished this monumental task singlehandedly and two transports. Combining the the command addresses the drive deserves a big round of applause from all SS-50 computer owners. economy of tape with the speed not designated as the system Jim has some other exciting projects nearing completion. and reliability of the disk, Exa- drive. This designation can be Many other major software and hardware projects are in the works tron gives you another choice. changed using the ASN com- and will be reported on here in coming issues. The CONTROLLER is a mand. NEWTAPE is the routine for certifying new wafers. A Users Groups, and the word has complete system on a board, ESF FOR THE TRS-80 comprising a synchronous serial fourth EPROM socket with room spread. interface, a data encoder, a clock for another IK of memory is Have all of you TRS-80 own- You don't find many sub- recovery circuit, and the nec- available for system expansion. ers out there seen the first two systems of this quality with an essary latches for peripheral The TRANSPORT uses state- ESFOA Newsletters? In the unconditional 30-day money- control. Also on board are of-the-art digital and linear tech- August and September issues of back guarantee. And there are EPROMs containing the soft- niques. It reads and writes Microcomputing? If you didn't, none, we believe, with a one-year ware drivers. There are four 14.400 bits per second, or op- borrow a friend's, or go see your full warranty. To quote from sockets for 2708s: three are used tionally 7200 bits per second, dealer, and read them - they de- the Users Manual, the specific- for the basic system software. with a typical error rate of 1 in scribe the TRS-80 ESF. It's purpose of the 30-dav money- The EPROMs occupy memory 100,000,000 bits. The transport delivered assembled and tested back guarantee is to ensure that addresses SC000-SCFFF in the has an average life of over 3500 at the factory, and within sec- all ESF owners are satisfied ESI standard configuration. However hours. It has controls for motor onds of connecting it up you the controller is addressable to on, fast forward, tape mark, are ready to go. If you have any any 4K block in memory, and wafer present, write protect, and questions about it, or need more HOW TO ORDER you can order custom EPROMs write enable. Power is supplied information, or want to order in any block to fit your system. by the controller. one. use our toll-free number. All versions of the Exatron See the ordering information in Stringy Floppy are covered by UTILITIES firmware consists The WAFER is a high-impact the box below. a 30-day moneyback guarantee of the low-level drivers and an plastic case, about the size of a and a one-year full warranty. The I/O package designed to reduce business card, and 3/16 of an The ESF for the TRS-80 has ESF' is delivered from the factory monitor dependency. No calls to inch thick, enclosing an endless met with great success. It fills assembled and tested. Prices for a monitor are used: I/O is accom- loop of tape. The tape is wound an obvious need, and thousands the SWTP version are given com- plished by direct manipulation somewhat like that in the famil- of the TRS-80 owners were, in plete in the text above. The TRS- of a serial interface for the con- iar 8-track cartridge. Wafers are effect, looking for the ESF be- 80 version is $249.50. which sole, and a parallel interface for available with various lengths of fore they even knew of its includes Microsoft Level III the printer. The console I/O is tape: 5, 10, 20. and 50 feet. The existence. Disks are still expen- BASIC. Instant Software on ESF done through a vector which average life of the wafer is 2500 sive. and are needed when you wafers are available at the list may be changed after initializa- passes. have to store millions in bytes, price. BUS-EX, the TRS-80 bus tion. The board cold-start rou- but they are not what most extension, is $15 for the 2- tine sets the vector at Port 2 if personal computer owners are PRICES for-1 model, and $5 for each there is nothing at Port 1. The looking for. Audio cassette re- added connector. Wafers at 5. printer is set at Port 7. The corders and playback machines, Cntrlr + Trnsprt $250.00 10, 20 and 50 feet are $2.50 utilities program has many use- along with audio-style cassettes, Trnsprt only $124.50 each and $20 for 10. Shipping ful subroutines which can be have their shortcomings, and TSC 6800 BASIC $39.95 and handling is $3.00 per order. used by other programs. YOU don't need to be told Microsoft BASIC $43.00 about that. [You should see CA residents add tax. Order fast SYSTEMS SUBROUTINES TSC Text Editor $31.00 some of our mail! Extracts from by calling our toll-free number are also contained in the firm- TSC Assembler $33.00 some of the letters, with horror below and giving your Visa or ware. The command TBAS will Advanced Programmer" stories and condemnation of MasterCharge number. load and execute TSC 6800 Guide $20.00 cassettes and recorders are ac- User's Manual and informa- BASIC, the fastest BASIC runn- tually unprintable! ] SoESFsare tion package is available at no ing on an 8-bit microcomputer. Ctrlr, 2 Trspts, Micrsft. & TSC being shown by their owners charge. Shipping and handling The command MB AS will load software $499.95 with pride to their local TRS-80 and execute Microsoft BASIC, is $3.00.

If you have any questions about the product, about Exatron, or HOT LINE 800-538-8559 ESFOA, please call the Hot Line. Address letters to ESFOA, 3557 Ryder St., Santa Clara, CA 95051. (408) 737-7111 Stringy Floppy is a trademark of Exatron Corporation ^en WITHIN CALIFORNIA

'Instant Software on ESF wafers are available at the regular HSTprice DET-POURRI

Good news at last. Things are help a lot. The 2040 disk utilizes automatically RUN. create a dual-density copy of it) looking up at Commodore, and the PET's IEEE port and comes and two memory tests, PageTest good news seems to be on the ho- set up as device #8. The manual and BlockTest. The examples on rizon. In my last PET-pourri I shows how to change this if you the other side are very helpful in was a bit hard on Commodore. need to. Which Disk for Your PET? showing how to use the com- This was due to a lot of negative Presently, the 2040 disk works mands explained in the manual. comments from other users as only with the new PETs. Soon Do you own several PETs, or Currently, Computhink is ship- well as lack of information from Commodore will begin shipping do you also have an Apple and a ping dual-density, dual miniflop- Commodore. Commodore is now- new ROMs for the old PETs; TRS-80? If you answered no, py drive systems for the PET. By trying to remedy all that. Many then the 2040 disk will work with then the Nestar dual-drive full- early fall 1979, they should be new people are being hired. Train- the upgraded old PETs. You can size floppy disk system is not for shipping this configuration with ing programs for PET dealers only write on the front side of you. The Nestar Cluster One is an added bonus: You can read have now been started. With a each diskette, which holds about ideal for schools. Up to 15 PETs, both sides of each diskette with- good training course, PET deal- 170K, but you can use the reverse TRS-80s and Apples can hook up out having to take it out and flip ers will now be able to help PET side of the diskette if you careful- to one Cluster One. Contact it over, thus having four sides of users locally with specific infor- ly cut out a notch on the left side Nestar (810 Garland Dr., Palo dual-density diskettes on line—or mation and assistance. Final ver- similar to the notch on the right. Alto CA 94303) for the name, ad- 800K on line. sions of the PET printer and Beware, however, that even the dress and phone number of your Computhink offers more than dual-floppy manuals are now be- smallest particle allowed inside nearest Nestar dealers. hardware. They also have a PL/M ing polished and should be avail- may ruin the diskette. compiler available for their disk able soon. I've seen preliminary A significant improvement has system. A BASIC and FORTRAN copies of these, and they are a been made in the Commodore compiler will be available soon. vast improvement over the pre- disk operating system. DOS 3.1 is Computhink Disk and News Also available now is a compre- liminary manuals. now included with every system. hensive data base. Contact Com- Commodore has products that It takes all the drudgery out of Most readers probably only puthink for details on these. I believe are far superior to the operating the floppy. Take errors have one PET. Two available others in the field. The problem is as an example. In the program disk systems, which I have seen learning how to unleash the hid- mode, your program can have a work, are worth your considera- den power in the PET, printer subroutine to check for errors. tion. One, of course, is the Com- Computhink Disk Notes and floppy. Full potential of the The final manual lists routines modore disk. The other is from PET is now beginning to be real- that do this. In the direct mode, Computhink (3260 Alpine Rd., In the short time that I've had ized. Both the PET printer and you only need to hit one key, > Menlo Park CA 94025). Compu- the Computhink dual-density disk floppy include microprocessors (greater than), and the error mes- think's disk system has been out system I've developed a Menu as controllers. A complete PET sage is displayed on the PET for over a year already. Readers program, written for the new system (computer, printer, flop- screen. in the East and Midwest should DOS, that will enable you to load py) can handle very sophisticated The new DOS also eliminates contact New England Electronics and run any program on either uses. In the future we should see the need to type OPEN and (NEECO), 679 Highland Ave., drive by hitting only one key. The some comprehensive, serious soft- PRINT# commands for accessing Needham MA 02194, the Com- program first puts a directory on ware available. the disks in direct mode. Now you puthink distributor for that sec- the screen. Then an index-key tion of the country. NEECO now character is printed in front of Some of this software is al- simply type > followed by what- has a new disk operating system each entry. The program checks ready being finalized. Commo- ever you normally would have as well as a dual-density option. which key is hit and goes to the dore has just signed a contract had to enclose in quotes in a Both sides of each diskette may correct location on the screen. It with the author of a fantastic PRINTS statement. Loading a be written on, unless the disk pro- PEEKs at what name is there and word processor. I saw a prelimi- program from disk is now easy. tect notch is covered, then the assigns it to F$. It then loads and nary version and was amazed. It Just type / (slash) followed by the diskette cannot be written on. runs F$ from drive D. The pro- was easy to use and had features I program name. DOS takes over With dual density, each diskette gram keeps track of which drive thought were only available on and does all the work for you, in- can hold about 200K. Presently, the directory came from and al- dedicated word-processing sys- cluding deciding which disk has the Computhink disk will only lows you to hit one key to see the tems. I should have a copy of it the program. If you begin with work with the old PETs; soon, it directory from the other drive. If within the week, so next month I the character t (up arrow) instead should be available for the new you modify each of your pro- should be able to relate more of / the program automatically PETs as well. grams to end by loading Menu, about it. will run once loaded. And re- you can have a continual chain member, the PET can use pattern The Computhink disk system is taking almost all the work out of matching for finding the pro- designed to be plugged into Com- running programs. gram. The program Backgammon puthink's Expandamem. It uti- Commodore Disk 3.4 can be loaded and run with lizes the PET memory expansion I'm not a professional pro- the following direct command: port rather than the IEEE port. grammer. My program is a bit tB*. Commodore's 2040 dual-disk The system comes with a diskette long and can be written in a more unit holds a great deal of poten- The asterisk tells the PET to containing utilities on one side condensed form, but the program tial. The reliability problems with load the first program that begins and helpful examples of disk pro- now includes many remarks and the earliest units have apparently with the characters preceding the gramming on the other. The utili- will be helpful in developing your been remedied, and the disk oper- asterisk. In this case, PET would ties include: Monitor, Datafile, own version. ating system has been improved. load the first program beginning Diskcopy (to copy a complete The trick is in learning to use the with B. If another program, such diskette from one drive to the system. The preliminary manual as Baseball 2.5, preceded Back- other), Random-Format (sets up Disk Software that comes with the disks is not gammon 3.4 on the disk you a direct-access file), DensityCopy too helpful. The final manual is could use: tBAC*. Once loaded (allows a dual-density drive to read Business Software is available being completed now and should into memory the program will a single-density diskette and for the Computhink disk from HARDWARE FOR TRS-80 SOFTWARE BY ACS • Pertec Disk Drives F0200 $375 00 ea. • Monitor No. 3 $29.95 These are 40-track Drives that are completely compatible Complete Machine Language Monitor for TRS-8U features Find, EDIT, Relocate, Symbolic Dump to Tape. etc. with the TRS-8ffTSnd Radio Shack Drives. 3.0 DOS included. • Monitor No. 4 $49.95 Will allow Turning Diskette over and Write on other side. All of the commands that reside in Monitor No. 3, plus: L 4 Drive Cable for Pertec Drives S35.00 RS-232 I/O. Disk Program I/O, Symbolic Dump to Oisk for • DECwriter III. 132 Character $2500.00 Loading into Disk Editor/ASM.. Track & Sec I/O for 110 to 9600 band El A tractor feed keyboard printer. This modification. is truly the nicest printer available. (30 day delivery) • PCLEND $15.95 • 701 Centronics TRACTOR FEED Will Patch ASCII files of Basic Programs or text or DATA Bidirectional Printer $1500.00 FILES so that they may be loaded into the Disk Version of the Electric Pencil for Editing purposes comes on Cassette 2'/> times as fast as the Radio Shack 779 Printer, has full that will automatically create a Disk file of PCLENO. size 132 Char. Carriage Bell tone. Complete with Cable • MAKE TAPE AND MAKE DISK plug in and use. Shipped Freight COO. for Cassette Dealers S69.95 • 200 m 16K Dynamic Memory Clips for Keyboard or Expan- These are two programs that will allow you to take any type sion Interlace, Lifetime Guarantee, complete $110.00 of Program from Disk and store it on tape for mailing Lifetime Guarantee. Complete with Instructions and Jumper purposes. When the user receives the program in the mail Blocks. on cassette, it is loaded into the computer which will • 10 Key Numerical Keypad Kit $79.95 automatically make a Disk file of the program. • CP/M 8. C BASIC for the TRS-80 » • TRS-80® Level II - 16k $750.00 CP/M Includes: M0VCPM, STAT, PIP, Dump, DDT, ASM • Expansion Interface $275.00 (8080), ED, plus 6 user manuals. • RS-232 C Interface $ 89.00 CP/M $150.00 C Basic 2 Includes: XREF2, CBAS2, and manuals. C BASIC 2 $99.95 ORDER NOW AND SAVE • G2 LEVEL III BASIC for TRS-80 Special $39.95 • TELCOM - Telecommunications for the TRS 80 '?..... $29.95 Just list the items you want Telecommunications for the TRS-8tt! allows one TRS-80" and mail this convenient coupon. to communicate with another through the RS-232-C over the phone line.

Orders received by 6:00 p.m. shipped next day on Master Charge, Visa, Send Check or Money Order payable to — Certified Check or Monev Order. Personal Checks require 14 days to SOFTWARE • P.O. Box 60097 Nashville, TN 37206 clear. No C.O.D. Collect calls not accepted. All Hardware warranted for 90 days Quan. Description Unit Price Total except Radio Shack equipment which is warrant- • Check ed through Radio Shack. Software guaranteed for replacement only. Prices subject to change • Money Order without notice. • MasterCharge AUTOMATED • Visa COMPUTER ^ A75 Card No. HANDLING CHARGE $1.50 SOFTWARE SERVICE TENN. RES. ADD 6% SALES TAX TOTAL Exp. Date. (615) 244-2798 Name Division of Address Scmpi^r liicrld NC. City _ State Zip- 625 Main Street • Nashville, TN 37206 0 REN THIS IS MENU FOR T>ISK 1 REN IT IIANPLES UP TO 3? FILES both Dr. Daley (425 Grove Ave., 2 REN IT HANDLES ALL CHARACTERS IK Berrien Springs MI 49103) and } REN NAMES EVEN SIMPLE REVERSE 4 REN FIELD IF THE REVERSE FIELD Sawyer Software (201 Worley 5 REN IS TURNED OFF U1 THIN THE NAME Rd., Dexter MO 63841). Business 6 REN 7 REN Software for the Commodore to INPUT "tCLRH 2 DOUNlt 2 RIGHT 3UHICH DRIVE! t[ 3 LEFIJ-JD disk is available from both NEE- 20 POKE 525,ltP0KE 527,99 30 «D,D CO and CMS Software (5115 100 PRINT "[HOnEUIlHIT THE [RVSJKEYCOFFJ OF TOUR PROGRAM CHOICEJJI- Menefee Dr., Dallas TX 75227). 110 PRIKT -[UPJlliHIT [RVS)«IOFF]ILEFTKDOUN]-[UP] TO STOP - HIT [RVSJ>[OFF3[DOUN]CLEFT3*[UP] FOR DRI 190 N=3:Be8!REK FIRST INDEX LOCATION Next time I hope to have more in- 195 F»0:REN INITIALIZE END FLAG formation on these. 197 IK>0:REN INDEX KEY INITIALIZE 200 FOR L=0 TO 19 It appears that both Dr. Daley 205 IF F=l THEN GOSUB 9200lG0T0 290:REN END HAS SEEN FOUND ALREADY 215 IF PEEK (N+L*40*2I»134 THEN F-1iCOTO 290:REM THIS IS THE FREE TRACK LINE and Programma International 220 POKE N«LM0,L*I29:REH THIS IS THE INDEX LETTER (3400 Wilshire Blvd., Los Angeles 230 POKE H*L*40*1,31iREN THIS IS A " • 290 NEXT L CA 90010) are offering programs 294 L«L»l:GOSUB 9200 on Computhink diskettes as well 300 IF F»1 THEN lOOOsREn SKIP SECOND COLUNN - ALREADY DONE 305 N«3290?:IK'0:REN SECOND COLUNN as on cassettes. (A software an- 310 FOR L=0 TO SiREN c Oft UVUXYZ nouncement for Programma in 320 IF F.| THEN GOSUB 9200:0010 390 330 IF PEEK(N*L,40*2>"134 THEN F'lsGOTO 390 Micro mentioned this, and Dr. 340 POKE N»I34 THEN F'ltGOTO 590>REN END FOUND 540 POKE N»L<40,L«147:REN THIS IS THE INDEX CHARACTER to see which disk system will be 550 POKE M»L*40*1,31 :REN THIS IS A " " supported by each of the many 590 NEXT L 1000 GET AAI!IF AA«'-- THEN IOOOJREM GET CHOICE PET companies. 1010 IF «»!••<• THEN 9990 1020 IF AAI»">" THEN D«2-D+1:GOTO 20:REM CHANGE DRIVES 1100 A>ASC (AAI > 1200 IF A>64 AND A<85 THEN N'32890|L»A-65|GOTO I300:REN SKIP 2ND COLUNN 1205 H-32909:REN FOR SECOND COLUNN 1210 IF A>'B5 AND A<»90 THEN L•A-65-20:GOTO 1300 New PET to Printer Update 1220 IF A>M8 AND A<>57 THEN L'A-42:G0T0 1300:REM FOROI23454789 1230 IF A>-35 AND A<«37 THEN L'A-19:GOTO 1300 1240 PRINT "CHONEU 3 RIGHTHRVS3PLEASE CHOOSE ONLY AN INDEX LISTEDCOFF]- The new PET is a big improve- 1250 GOTO 1000 ment over the old PET. I haven't 1299 END 1300 FI"""SRV»0!REH INITIALIZATION yet used a PET printer, but I'm 1305 PRINT -[HOME][ 23 DOUNH 3 RISHT]>»»»»»»CRVSJHERE IT CONES... [OFF]" told that it can print uppercase 1310 FOR Ks0 TO 15 1320 FL"PEEK(N*L*40*K)tREN VALUE OF CHARACTER and lowercase letters as they ap- 1322 IF FL>128 AND RVO THEN GOSUB 9000 pear on the screen. I don't know 1 324 IF FL<1X1 AND RV»I THEN GOSUB 9500 1326 IF FL>I28 AND RV-2 THEN GOTO 9400 why Commodore didn't do this in 1328 IF FL>I28 AND RV«1 THEN FL-FL-128 their 2040-floppy manual. The 1330 GOSUB BOOOtREN CONVERT TO STRING CHARACTER 1390 NEXT K good news on the manual is that it 2000 IF RV THEN GOSUB 9700 is only temporary; a final im- 2010 IX,D,F» 8000 REM CONVERT PEEK 10 CHR« proved version is now being com- 8002 REN FL IS PEEK VALUE pleted. There's a problem in us- 8004 REN FT IS CONVERTED FOR CHRI 8006 REM Fl IS THE STRING CHARACTER ing a printer such as the Teletype BOIO IF FL>»0 AND FL<-3I THEN FT"FL*44 43 via RS-232. Apparently the old 8020 IF FL»>32 AND FL<«43 THEN FT-FL 8030 IF FL>»44 AND FL<»95 THEN FT=FL»128 PET did not use true ASCII code, 8040 IF FL>*96 AND FK-127 THEN FT*FL»64 and the RS-232 interfaces cor- 8100 IF FLO 28 THEN F H = CHRI (FT > :GOTO 6800 8800 REM Fl I IS CHRI FOR THIS CHARACTER POKE rected for this. The new PET 8810 FMFI»FII sends true ASCII code, which is a 8999 RETURN 9000 RV'ltREN REVERSE FOUND good improvement, but either the 9010 FI=FI»"(RVS]" interface made for the old PET 9020 FL»FL-12B 9099 RETURN will have to be modified or a pro- 9200 IF IK«1 THEN 9299 gram written to convert upper- 9210 1K-1 9215 POKE HH*40-40,30:REN • case to lowercase. If anyone has 9220 POKE MH*40,1 37: REM I 9225 POKE N»L»40»1,I42:REN N the answer, please contact me. 9230 POKE NiL«40«2,l32!REN D 9235 POKE N*L440 + 3,I33:REM E 9240 POKE N»L«40»4,152:REN X 9245 POKE N»L«40»5,I60:REM 9250 POKE N»L«40>6,I39:REN K 9255 POKE NH«40*7,133:REN E 9260 POKE N«L*40*8,I53:REM 1 Upgrades for Old PET 9299 RETURN 9500 RV-2:REM REVERSE FOUND AND TURNED OFF 9510 FI>FI.-[0FF3" Old-PET owners now may buy 9599 RETURN a set of new ROMs for their old 9600 PRINT -CHONEU 2 RIGHTKRVS]TOUR FILE NANE IS TOO CONFUSING FOR ME[OFF3" 9610 GOTO 1000 PET. There are two types of 9700 FI»LEFTI(FI,I6> ROMs. Both are packaged in a set 9799 RETURN 9990 PRINT -[HONEH 21 DOUN]- of seven ROMs and are priced at 9992 POKE 525,9 $89.95 per set from Commodore 9994 POKE 527,145 :REN UP 9996 FOR Z-528 TO 533:P0KE Z,32:NEXT ZsREM SPACE (3330 Scott Rd., Santa Clara CA 9998 POKE 534,I45:P0KE 535,HUREN SHIFT RETURN 95050). To upgrade your old 9999 END PET, simply remove the old ROM Menu program (contact author—not c/o Microcomputing, please—for missing part of line 110). set and replace it with the new OUR VISIBLE MEMORY ADDS FUNCTION AND FUN TO YOUR 6502

This DOT MATRIX display board doubles as an 8K MEMORY You can use it as a display, memory expansion or both with graphic and text display software available You get resolution graphics with no wait states, no snow, and no processor overhead K-1008 ASSEMBLED and TESTED $240 00. BARE BOARD 540.00 K-1008-1 GRAPHIC/TEXT UTILITY SOFTWARE LISTING 520 00

As a dot matrix formatted 200 high by 320 wide, it allows high resolution patterns to be displayed and evaluated It enhances system performance for data acquisition displays, math equa- tion plotting, etc.

For charts and graphs, it is valuable in the educational, research and business fields. Shown to the right is a single period of a complex frequency waveform and its frequency spectrum chart.

The way you check line-by-line with an A P Intra-Switch or Intra-Connector. You plug your Intra-Switch in-line with standard socket connectors, and instantly you've got a separate, For text display, dot matrix is the ultimate Any character set the user desires is possible. Even subscript and superscript in independent on-off switch for each at right angles. Instant line-by-line the same column, and—mixed text and graphics The improved man-machine interface for an unskilled operator increases pro- and every line in your flat ribbon probeability—and an easy way to ductivity. cable. To switch, you nudge with a tap your system and daisy chain it pencil point. It's that quick. into new areas. Imagine how much time and Both Intra-Connectors and Intra- trouble Intra-Switch will save you in Switches come in 20, 26, 34,40 and your diagnostic and quality testing, 50-contact models. your programming and selective Where? At your nearby A P deal- line Inhibiting. er. Where's that? Phone (toll-free) Or, plug in your Intra-Connector 800-321-9668. And ask for the com- (see box) the same way, and you plete A P catalog, The Faster and have an extra set of male contacts Easier Book.

Graphics allows you to program games with much more ac- curate representation of your game because YOU DETERMINE AP PRODUCTS THE SHAPES on the display, not a ROM character generator. Our LIFE program allows tremendous creativity in creating INCORPORATED ^22 complex colonies for observation of generation growth and decay Box 110 E* 72 Corwin Drive Painesville, Ohio 44077

Developed by a leading group of New England engineers for in- Tel. 216/354-2101 terface with the three 6502 KIM BUS systems (KIM, VIM. AIM). TWX: 810-425-2250 The K-1008 requires only the processor card and its power sup- ply to function as a memory Add a monitor and you have graphics and text display available Micro Technology also makes K-1000 Power Supplies, K-1005 Card Files, K-1002 8 Bit Music Systems (with advanced software), K-1020 Regulated Wire Wrap card, K-1012 IO/COMM/PROM/2708 Programmer Faster and Easier is what we're all about. card. K-1016 16K Memory, all sold assembled and tested or as Dare boards Write for technical information, prices and terms.

Overseas orders—include $3.00 for shipping

Micro Technology Unlimited l-' M44

P.O Bos 4596 Manchester NH 03109

v' Reader Service—see page 227 Microcomputing, October 1979 19 ROM set. Once upgraded, your save his old ROM set. Who knows scribed in detail in Pipeline, Vol. Meadow NY 11554. old PET will use the same mem- —maybe someone will put out a 4, No. 2. Pipeline d available free DAK Industries and Long ory locations as a new PET. board for the new PET allowing from Conduit. Simply send a Electronics have been Thus, most PEEK or POKEs it to use the old ROMs.) postcard and ask to be placed on mentioned, but I have no ad- used in old PET programs will their mailing list. dresses to list. not function properly and may Microphys Programs (2048 even lock out your PET. You can Ford St., Brooklyn NY 11229) modify your programs using my Program Protection Encore has announced nearly 100 pro- conversion chart starting on p. 72 grams in various subjects, mainly Stop Key Disable of the July issue of Microcomput- Many software companies are for high schools. Subjects in- ing. Since programs using ma- concerned about illegal copying cluded are chemistry, physics, To disable the STOP key, your chine-language subroutines prob- of their programs and are now at- utilities, math and vocabulary. program will have to determine ably won't work with the new tempting to protect their pro- Several of these programs are on which version of PET it is run- ROM upgrade, what becomes of grams from being copied. Com- also being offered by Commo- ning. A PEEK at location 50003 your old ROM set? Do you throw puthink has a method to protect dore. Some of the programs are will confirm whether it's a new or it away? disk programs with their disk sys- computer assisted instruction, an old PET. A new PET will re- Small System Services, Inc. tem. I've also discovered an easy while others are individualized in- turn a 1, while the old PET will (900 Spring Garden St., Greens- method with their system. Of struction. return a 0. See my article on p. 72 boro NC 27403), has what seems course, I won't tell you how it's Programs from both Conduit of the July issue for a discussion to be an excellent answer to this done, but any software marketer and Microphys should prove use- on using this information. Briefly, ful in the classroom. Commodore the following line will allow you also has announced programs for to use variable PT as the PET educators. Their programs in- Type: 0 PT = PEEK(50003).

1 PT = PEEK(50003):SL = 537 - 393«PT:DL = 136- 87.PT:POKE SL. Dl. clude a series in elementary lan- To disable the STOP key on the guage arts written by Thorwald old PET, POKE 537,136; on the Example 1. Esbensen. I hope to see these new PET, POKE 144,49. Micro soon. I have seen other programs Software Systems (PO Box 1442, by Mr. Esbensen, and he does a Woodbridge VA 22193) was kind wonderful job of making them 900 PT = PEEK(50003):SL = 537 - 393

DOS is composed of four pro- TRS-80 Minifloppy Disk Drive grams: a menu, a simple disk file manager, disk utilities (which in- Percom Data Co., 211 N. clude backup, erase and copy) and Kirby, Garland TX 75042, is the Percom notebook. One of the advertising a TRS-80-compatible niceties is a merge command that add-on minifloppy disk drive. will merge a routine from disk into You can purchase a single, double a program in memory. This allows or triple disk-drive unit to expand building an extensive subroutine your present system. You will need file on disk and merging into the an expansion interface, TRSDOS program. You write the subrou- diskette and TRSDOS manual to tine once and then call it up use the Percom drives. These same anytime you want it. items are required to run the ISI did have one problem with Tandy (Radio Shack) disk drives. the Wangco drives. There is an in- Apple II Business System. Instant Software, Inc. (1SI), terlock device in these drives that purchased a triple drive unit, we were activating by finger to get which arrivedjvith three Wangco the door closed. The disk drives personal computer and home en- BASIC interpreter. Model 82 disk drives (Pertec FD are mounted on edge in the Per- tertainment center in one. It can be The Imagination Machine has a 200 disk drives are also used), a com housing unit. With the hous- used for educational guidance, built-in music synthesizer with a cabinet with power supplies, a ing on its side, the disk drives are home and personal-budget man- range of three octaves including new ribbon interconnect cable, horizontal with their doors open. agement, as well as for leisure-time sharps and flats. Expandable op- a MICRODOS diskette and In this position the interlocking activities such as games of skill, tions include printers, floppy MICRODOS manual. Each disk device started working properly. chance, dexterity and multi-player disks, word-processing capa- drive is packed separately, and This particular door interlock re- competition. bilities and expandable RAM plus you have to assemble the units into quires proper orientation to func- Through a simple hookup with coupler modems. the case. The only tool we needed tion, but this in no way impairs the your existing TV set, you can start APF Electronics, Inc., 444 was a straight-blade screwdriver. use of the drives. We overcame the up your Imagination Machine, Madison Ave., New York NY The disk drives were ready to be problem of the sticking door inter- which is user programmable. At 10022. Reader Service number connected to the TRS-80 in about lock. A103. half an hour. " high resolution, the system's color That the Percom system func- graphics consist of 128 x 192 The best surprise came when we tioned properly the first time is characters with up to eight color tried to run the system. All three recommendation enough, but variations. disk drives functioned properly couple that with MICRODOS and Standard features include 10K Business System right from the start. We had a its low cost, and you have a good ROM and 9K RAM memory, Tandy single drive that we sent system for the money. Reader Ser- typewriter-type keyboard, 53 keys back to Tandy three times before it The Apple II Business System vice number P64. with a unique shifted "BASIC functioned correctly. The Wangco combines all the advantages of a Edward E. timer Keywords" button, two game- drives are slower (40 millisecond personal computer—portability, Technical Dept., ISI style controllers, 32 characters x track access time) than the Shugart accessibility and affordability— 16 lines screen format, six function drives used by Tandy, but the time with versatile business software. built-in cassette tape deck, digital difference is not a significant fac- The configuration includes the and audio information record/ tor during operation. Data trans- Apple II Plus Computer, which is Imagination Machine playback, built-in microphone I fer to and from the disk drives has an upgrade of the Apple II first jack, cartridge connector plus an I been solid and error free. sold in 1977, 48K bytes of RAM The Imagination Machine is a internal operating system and memory, two disk drives, a video The MICRODOS is a simple, monitor, a printer and the Con- I yet versatile, disk operating system troller software package. I for the TRS-80, but it is not com- The system has an expanded I patible with TRSDOS. MICRO- version of built-in BASIC that makes it well suited for business problem solving. In addition, an Auto-Start ROM chip provides automatic disk loading as the system turns on, reset protection and easy screen editing. The Con- troller business software package, designed especially to meet the needs of smaller businesses, con- sists of three program modules:

In our July 1979 mention of Microsoft's M6800 BASIC (p. 16), we failed to state that the BASIC is licensed only on an OEM contract basis; it is not now directly available to end users. Percom's TRS-80 triple drive unit. APF's Imagination Machine. costs $249.95. Percom Data Company, Inc., 211 N. Kirby, Garland TX 75042. Reader Service number P62.

Video/Disk for the Sorcerer

A new Video/Disk peripheral attachment for the Sorcerer com- puter from Exidy Data Products, 390 Java Drive, Sunnyvale CA 94086, contains a 12 inch video display and dual mini-floppy disk drives with data storage capacity The LVM-80. Exidy's Video /Disk. of 630,000 words. The swivel- based unit attaches directly to the General Ledger, Accounts Re- large business mainframes. The Electric Window because the gen- Sorcerer's keyboard enclosure to ceivable and Accounts Payable. vocabulary capacity of the erated display is like a window- form a desktop computer system The Controller package in- LVM-80 is 512 seconds of speech, through which you can observe the no larger than a video terminal for cludes a unique fail-safe feature of or approximately 1024 individ- memory space where characters small-business data processing. The disk drives utilize a unique the data entry system that signals ually addressable messages. are being input and manipulated, precision metal positioner to typing errors with an audible Memory capacity of the LVM-80 this product is convenient in all ap- achieve their storage capacity. warning. The Controller auto- is 16K (EPROM) and can be plications, but has particular value matically makes copies of data erased and reused should the user in text and word processing where The high-performance video files for historical purposes in case require reprogramming of the the effects of editing and line display utilizes a P31 phosphor for of lost originals and automatically vocabulary by Votrax. justification are instantly visible. readability and a 20 MHz band- prints reports before the system The LVM-80 communications Electric Window features in- width for clear pictures to easily will allow the user to close out the processor services up to 64 clude: two character generators— handle computer generation of monthly books. The system costs simultaneous telephone lines and, one for standard characters and 240 x 512 graphic resolution. $4995. through a process of digitizing ac- one that can be programmed for Software included with the hard- Apple Computer, Inc., 10260 tual human speech, can "speak" special characters—dual intensity, ware consists of the popular Bandley Drive, Cupertino CA words and phrases with a quality highlighting alphanumeric dis- CP/M operating system, Z-80 as- 95051. Reader Service number that is virtually indistinguishable play; display scrolling controlled sembler, text editor, linking loader and Microsoft Disk Extended A28. from the original speaker. by a single programmable register; BASIC. The Exidy Video/Disk Votrax, 500 Stephenson High- descenders on lowercase letters for costs $2995. Reader Service way, Troy MI 48084. Reader Ser- improved readability; program- number E44. vice number V26. mable display positioning; and Graphics Digitizer programmable interlaced or non- interlaced scan. The Electric Win- The Simple II is a new digitizer dow is compatible with standard aimed at systems with graphics ap- Video Display Board video monitors. The instruction Microcomputer Modem plications ranging from medical manual supplied with the Electric Window includes a complete op- analysis to interactive graphics to The Electric Window video dis- The Micromodem 100, a com- erating system listing. An optional engineering design. The Simple II play board is memory-resident, plete data communications system PROM operating system is also is an 11 x 11 inch self-contained programmable and displays up to for S-100 microcomputers, com- available. The Electric Window digitizer with 400 lines per inch 24 80-character lines. Named the bines on a single board functions resolution and 10 mil accuracy. X-Y output is variable up to 240 coordinate pairs per second. The Simple II, from Talos Sys- tems, Inc., 7419 E. Helms Dr., Scottsdale AZ 85260, will replace the Simple One as the firm's small low-priced graphics digitizer. The new unit will sell for $1065. The Simple II will not replace the 600 series digitizers the firm currently offers, but will serve where high resolution, backlighting or rear projection are not necessary. Reader Service number T70.

Digitized Audio Response System

The Votrax LVM-80 is a solid- state multiplexed audio response system that provides multi-line audio output and Touch-Tone in- put handling capability for micro- computers, minicomputers and The Simple II. The Electric Window. that formerly required a modem, an automatic calling unit and serial and parallel interfaces. The new board is a sophisticated com- puter-to-computer or terminal-to- computer modem for small com- puter systems. The Micromodem 100, fully S-100 bus compatible, including 16-bit machines and 4 MHz pro- cessors, converts digital data into analog signals for transmission over regular voice telephone lines. Because it is a Bell System 103 compatible modem, it can com- municate with the most commonly The VDB-1 Smoke Writer. The Micromodem 100 and Microcoupler. used modems in North America. It operates at either of two software- selected baud rates—300 baud and 16 Perimeter Park Drive, PO Box good use of this video board. Price for practicing specific positions. a jumper-selectable speed from 45 9884, Atlanta GA 30319. Reader is $349. Price is $119.95. to 300 baud—and is equipped with Service number H20. Smoke Signal Broadcasting, Chafitz, Inc., 1055 First Street, an FCC registered Microcoupler 31336 Via Colinas, Westlake Rockville MD 20850. Reader Ser- data access arrangement that feeds Village CA 91361. Reader Service vice number CI51. the signal into the telephone line number S46. through a modular connector pro- Smoke Writer vided by the local telephone com- pany. Because of this direct con- The VDB-1 Smoke Writer is a Computer and Terminal in One nect feature, the Micromodem 100 fast SS-50 bus video display board Batten-Operated can automatically answer the featuring the MC6845 CRT con- Chess Computer NCE/CompuMart, PO Box phone or dial a number. The troller chip to provide total control 8610, Dept. PI, Ann Arbor Ml Microcoupler provides direct ac- over display formats. The new The Boris Diplomat is a full-fea- 48107, combining the PET com- cess to the telephone system with- board controls an 80 x 24 display tured, microcomputer-based chess puter and NCE's own design in a out the losses or distortions asso- with 32 graphic characters and has computer that is designed for direct spin-off from the PET tech- ciated with acoustic couplers and nology, announces the TC 2001, a upper and lowercase characters travel. It is compact (8 x 7 x 1 >/i without a telephone-company- computer and a terminal in one with lowercase descenders. 128 inches), portable and battery op- supplied data access arrangement. unit at a price lower than a ter- character graphics are optional. erated (operates several hours on minal alone. The TC 2001 func- Its programmable character set, a six AA batteries, not included, or The Micromodem 100 serves as tions as a full duplex, dumb ter- total of 128 characters, is in a 2K on the ac adapter, included), with a convenient data communica- minal that can be used in con- EPROM with 256 character 4K a built-in chessboard with pieces. tions tool between home and of- junction with remote timesharing EPROM optional. Designed with various opera- fice. an automatic data collector services, and also as an advanced The Smoke Writer video tional strengths, the Diplomat will from remote terminals, an intelli- personal computer. It incor- play at a level that will teach a gent terminal and allows imple- board's other important features porates one of today's most pop- child or will keep the attention of a mentation of remote software include: reduced intensity or ular microprocessors, the MOS master. As a teacher, it suggests maintenance and customer sup- reversed video, programmable 6502, for fast and reliable opera- moves for the unsure beginner. port. It sends programs, letters display rate (10-5000 characters tions. It is available with 8K, 16K The position programmer allows and other data over the telephone per second), protected fields, ad- of RAM memory. The ROM and provides access to remote data dressable cursor, 2K video display more advanced players to set up memory size is 14K. The TC 2001 bases. It is software compatible RAM accessible by the CPU as special board positions to practice uses BASIC language (Level 11) with the D. C. Hayes Associates standard RAM memory, 128 bytes specific strategies. Beginners can and is fully expandable through 80-103A Data Communications of scratchpad RAM and IK use the position programmer to re- IEEE, TTL parallel, second cas- Adapter, but offers improved per- EPROM for software drivers. move pieces for handicapping or formance and a direct connect and Either a business program that receive sensitivity of - 50 dBm. needs protected fields or a cursor- D. C. Hayes Associates, Inc. based editor application will make

The Boris Diplomat. The TC 2001. Welcome to Percom's Wide World

Each LFD mini-disk storage system includes: • drives with integral power supplies in an enamel-finished enclosure • a controller/interface with ROM operating system plus extra ROM capacity and 1K of RAM • an interconnecting cable • a comprehensive 80-page users manual Low-Cost Mini-Disk Storage in the Size You Want. Percom LFD mini-disk drive The LFD-400'" and -400EX" systems systems are supplied complete and the LFD-8001" and -800EX® systems and ready to plug in the moment are available in 1-, 2- and 3-drive configurations. The -400, -400EX drives they arrive. You don't even have store 102K bytes of formatted data on to buy extra memory. Moreover, 40-track disks, and data may be stored on software support ranges from either surface of a disk. The -800. -800EX assembly language program drives store 200K bytes of formatted data on 77-track disks. development aids to high-speed The LFD-1000'" systems (not pictured) disk operating systems and have dual-drive units which store 800K business application programs. bytes on-line. The LFD-1000" controller accommodates two drive systems so that a user may have as much as 1 6M bytes on-line. Mini-disk storage system prices: 1-DRIVE 2-DRIVE 3-DRIVE MODEL SYSTEM SYSTEM SYSTEM For the SS-50 Bus: LFD-400" $ 599.95 $ 999.95 $1399.95 LFD-800" 895.95 1549.95 2195.95 For the EXORciser* Bus: LFD-400EX" S 649.95 $1049.95 $1449.95 LFD-800EX'4 945.95 1599.95 2245.95 LFD-1000" (dual) $2495.00 (quad) $4950.00 — EXORciser Bus LFD-400EX.' -800EX " Systems

Data Terminal & Two-Cassette Interface — the CIS-30+

I|«MIN»1 T4PI DATE

»u'0 LOCAL CIS-30 * PEP5CM

• Interface to data terminal and two cassette recorders with a unit only 1/10 the size of SWTP's AC-30. • Select 30, 60 or 120 bytes per second cassette interfacing: 300, 600 or 1200 baud data terminal interfacing • Optional mod kits make CIS-30+ work with any microcomputer. (For MITS 680b. ask for Tech Memo TM-CIS-30 + -09.) • KC Standard/Bi-Phase-M (double frequency) cassette Upgrade to 6809 Computing Power. Only $69.95 data encoding. Dependable self-clocking operation Although designed with the SWTP 6800 owner in DIP header, and re-inserting the original • Ordinary functions may be accomplished with 6800 mind, this upgrade adapter may also be used with components. Also available for your upgraded Mikbug* monitor most other 6800 and 6802 MPUs. The adapter is system is PSYM0N® (Percom SYstem MONitor), Prices: Kit, $79.95: Assembled, $99 95. Prices include a comprehensive instruction manual. Also available: Test supplied assembled and tested, and includes the the operating system for the Percom 6809 Cassette, Remote Control Kit (for program control of 6809 IC, a crystal, other essential components and single-board computer. PSYM0N® on 2716 ROM recorders), IC Socket Kit. MITS 680b mod documentation user instructions. Restore your original system by costs only $69.95. On diskette (source and object and Universal Adapter Kit (converts CIS-30+ for use with merely unplugging the adapter and a wire-jumpered files), only S29.95. any computer). of 6800 Microcomputing 6800/6809 SOFTWARE System Software And looking into' is just what 6800 Symbolic Assembler — Specify assembly options you do with the Electric at time ol assembly with this symbolic assembler. Source listing on diskette $29.95 Window- as you peer right Super BASIC — a 12K extended random access disk BASIC into memory space where lor the 6800 and 6809. Supports 44 commands and 31 func- tions. Interprets programs written in both SWTP 8K BASIC characters are being input (versions 2.0, 2.2 & 2.3) and Super BASIC. Features: 9-digit and manipulated. Display BCD arithmetic. Print Using and Linput commands, and much is memory-resident, more. Price $49 95 T0UCHUP" — Modifies TSC's Text Editor and Text Pro- programmable and generates cessor for Percom mini-disk drive operation. Supplied on up to 24 80-character lines. diskette complete with source listing $17.95 Other features include: Operating Systems INDEX '" — This easy-to-use disk-operating and file man- standard character agement system for 6800 microcomputers is fast. I/O devices generator plus provision for are serviced by interrupt request. INDEX1" accesses peripherals optional special character the same as disk files — new devices may be added without changing the operating system. Other features: unlimited generator number ol DOS commands may be added • over 60 system The Electric Window.® entry points • display only those files at or above user-specified • dual intensity, high-lighting file activity level • versions available for SWTP MF-68, Smoke's alphanumeric display Worth Looking Into. $249. BFD-68 and Motorola's EXORciser*. Price $99.95 MINIDOS-PLUSX " — An extension of the original • scrolling by a programmable WINDEX'" is a fast video display driver program for MINIDOS'" for LFD-400" mini-disk systems, MINIDOS- register • programmable the Electric Window'" . WINDEX " also features: PLUSX1" manipulates files by six-character names. Supports display positioning program and keyboard control of character up to 31 files. Resident commands include Initialize, Save. generators • displayable control characters — under Allocate, Load. Files (directory list), Rename and Delete. • programmable interlaced or program control • automatic scrolling • a driver Supplied on 2708 ROM with a minidiskette that includes non-interlaced scan routine for the parallel input keyboard feature of the transient utilities such as Copy, Backup, Create, Pack and Print Percom 6809 Single-Board Computer, the SBC/9™ Directory. Price $34.95. • descenders on lower case • auto-linking to PSYMON'". the ROM operating PSYMON '" — Percom SVstem MONitor for the Percom letters • users manual with single-board/SS-50-bus-compatible 6809 computer accom- system for the SBC/9'" • Prices: ROM version: modates user's application programs with any mix of peripher- application instructions and S39.95; LFD-400™ compatible diskette (source and als without modifying programs. PSYMON- also features listing of WINDEX® driver. object files): S29.95. character echoing to devices other than the communicating device, sophisticated register and memory dump routines and more. Price (on 2716 ROM) $69.95. PDQ from PDC! WINDEX" — Described in detail elsewhere on this page. In the product development queue and available soon: the SBC/9" Business Programs (Single-Board-Computer/6809) — stands alone as a control computer, but also General Ledger — For 6800/6809 computers using Per- compatible with the SS-50 bus for use as an MPU card. Includes PSYMON® (Percom com LFD mini-disk storage systems. Requires little or no SYstem MONitor) in a 1K ROM and provides for additional 1K of ROM. Also includes 1K knowledge of bookkeeping because the operator is prompted of RAM. Features: Super Port — provision for multi-address. 8-bit bidirectional data with non-technical questions during data entry. General Ledger updates account balances immediately — in real time, and will lines • an intelligent data bus for multi-level data bus decoding • an on-board 110-baud print financial statements immediately after journal entries. User to 19 2 kbaud clock generator • extended address capability — to 16 megabytes — selects and assigns own account numbers: tailors financial without disabling baud clock or adding hardware. And much more. Supplied with statements to firm's particular needs. Provides audit trail. Runs PSYMON® and comprehensive users manual. Price S199.95. under Percom Super BASIC. Requires 24K bytes of RAM Supplied on minidiskette with a comprehensive users manual. Price $199.95 Full Feature Prototyping PC Boards FINDER " — This general purpose data base manager is written in Percom Super BASIC. Works wth 6800/6809 com- puters using Percom LFD-400™ mini-disk drive storage sys- All of the features needed for rapid, tems. FINDER " allows user to define and access records using straightforward circuit prototyping. Use his own terminology — customize file structures to specific needs. Basic commands are New. Change. Delete, Find and 14-, 16-, 24- and 40-pin DIP sockets Pack. Add up to three user-defined commands. FINDER plus • SS-50 bus card accommodates 34- and Super BASIC require 24K bytes ol RAM. Supplied on minidisk- 50-pin ribbon connectors on top edge, ette with a users manual. Price $99.95 10-pin Molex connector on side edge* I/O Mailing List Processor — Powerful search, sort, create card accommodates 34-pin ribbon and update capability plus ability to store 700 addresses per connector and 12-pin Molex on top edge minidiskette make this list processor efficient and easy to use. Runs under Percom Super BASIC. Requires 24K bytes of RAM. Supplied on minidiskette with a users manual. Price $99.95. From the Software Works Development and debugging programs for 6800 nCs on disk- • I/O card is 1-% inches higher than ette: SWTP I/O card • interdigitated power Disassembler/Source Generator $30.95 conductors • contacts for power regulators Reloc'tng Disas'mblr/ Segmented Text Gen $40.95 and distributed capacitance bypassing Disassembler/Trace $25.95 • use wire wrap, wiring pencil or solder Support Relocator Program $25.95 wiring • tin-lead plating over 2-oz copper Relocating Assembler/Linking Loader $55.95 conductors wets quickly, solders easily SmithBUG** (2716 EPROM) $70.00 • FR4-G10 epoxy-glass substrate.

1/2-Price Special on Hemenway Software! CP/68+ disk operating system $ 49.97 STRUBAL+? compiler $124.97 EDIT68 text editor $ 19-97 To place an order or request additional literature call toll- MACRO-Relocating Assembler $ 39.97 free 1-800-527-1592. For technical information call (214) Linkage Editor (LNKEDT68) $ 24.97 Cross Reference utility $ 14.97 272-3421. Orders may be paid by check, money order. COD or PEFGOM charged to a VISA or Master Charge account. Texas residents must add 5% sales tax. PERCOM DATA COMPANY. INC "trademark of Percom Data Company. Inc* 211 N KIRBY GARLAND TEXAS 75042 PRICES AND SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE * trademark of Motorola Corporation (2141 272-3421 tTrademark of Hemenway Associates Company ••SmithBUG is a trademark of the Software Works Company complement number. User-select- able output ranges of 0 to + 5 V, 0 to +10 V, ±2.5 V, ±5 V and ± 10 V are available. The board may be addressed as I/O ports or memory mapped. Only four lines of software are required to pro- gram these DACs. Price is $395, assembled and tested. Tecmar, Inc., 23414 Greenlawn Ave., Cleveland OH 44122. Read- er Service number T68.

The DE-80. Super Isolator sette and memory ports. Versions supply included. wait states are available. The PB1 Now you can protect against ex- are available with either a full in- Microsette Co., 777 Palomar has gold-plated edge contacts, treme interference with the Model dustry standard or calculator-type Ave., Sunnyvale CA 94086. Read- plated through holes, low-profile ISO-3 from Electronic Specialists, keyboard, which includes a er Service number M67. sockets and factory prime parts; Inc., 171 S. Main Street, Natick cassette drive. Price of the unit the PC board is made of FR-4 blue MA 01760. The Model ISO-3 in- with 8K RAM is $795. epoxy and is solder masked for cludes "superfiltering" for each As a terminal, the TC 2001 ease of assembly. Price is $145, of three 3-prong sockets. Heavy- S-100 EPROM Programmer and works at a 300 baud rate. It ac- kit, and $219, assembled and duty spike and surge suppression 4K/8K EPROM Board cepts RS-232 and outputs TTL tested. is also included. voltage. The TC 2001 has both up- Solid State Music, 2116 Walsh Intended for microprocessor in- per and lowercase characters, as The PB1 programming board Avenue, Santa Clara CA 95050. stallations in industrial or severe well as graphics, on the 40 charac- for 2708 and 5 V 2716 EPROMs is Reader Service number S108. interference-prone environments, ter by 25 line CRT display. A PET designed to meet all manufactur- the Super Isolator also provides computer can be converted to ers' data sheet requirements for protection against damage from obtain the same terminal capa- programming 2708s or 2716s. PB1 lightning and electrical machinery bilities by plugging a module, sold has two separate programming D/A Converter Board spikes and surges. It connects to through NCE for $69, into the circuits so 2708 or 2716 (5 V) the ac line with a standard 3-prong user port. NCE also offers an EPROMs can be programmed The Tecmar S-100 D/A board plug and can isolate and protect an acoustic coupler and cable for without modifying the board. designed for applications requir- 1875 Watt total load, with each both originate and answer mode. Two textool programming sockets ing high-speed accurate digital-to- socket capable of isolating a 1000 Reader Service number N7. are provided for easy insertion and analog conversion, including real- Watt load. Price is $72.95. Reader removal of EPROMs being pro- time applications, supports four Service number E36. grammed. Programming voltage independent high-speed digital-to- is generated on-board by a dc-dc analog converters (DACs) with as- converter—no need for an exter- sociated latches. Each DAC op- Data Enhancer nal power supply. Programming erates completely independent of Level II BASIC Shorthand sockets are DIP switch address- the rest. The DACs have a conver- The DE-80 is an attachment be- able to any 4K boundary. Special sion time of three usee, which en- tween the Radio Shack TRS-80 TSHORT is a Level II BASIC safety features to prevent acciden- ables them to operate at maximum and its cassette player to enable shorthand that gives you single tal programming include an LED computer speed. A 12 bit latch you to read marginally recorded keystroke entry for 32 difficult-to- indicator and an on/off switch for drives the inputs of each DAC. data over a wide range of volume programming voltage. Software Another four bit latch for each settings on the recorder. It will listings are included for checking DAC holds the four new most sig- allow you to read either Level I or EPROM erasure, programming nificant bits waiting for the arrival Level II cassettes from a volume and verification. of the new least significant byte. setting anywhere between 4 and 10 on the Radio Shack CTR-type re- The board also includes four This allows the DAC to hold its corders, as compared to between 5 additional on-board EPROMs previous value until an entire new to 6'/i if no enhancer is used in be- that are independently addressable word is presented to it. tween. However, the DE-80 can- by DIP switch to any 4K (2708) or All the latches are set to zero by not make up for bad recordings or 8K (2716) boundary above 8000 reset. To modify the contents of a major tape dropouts where data hex. Unused sockets do not enable latch, and hence the output of a has distorted playback wave- data bus drive. The board is fully DAC, send two bytes to the de- forms, hum and variations in buffered, and 0 to 4 clock cycle vice. The input is a 12 bit two's The Model ISO-3. amplitude. The DE-80 consists of a small 4 x 2'A inch box with only the read wire coming in and out of the box. It is inserted between the recorder and TRS-80 so there is no warran- ty violation from this improve- ment. The data enhancer also has an LED lamp that glows when data is being detected. The LED is useful for locating gaps between programs when more than one WIMffKKF^* program is recorded on the cas- sette. Price is $45 with the power PBl EPROM programmer. Tec mar's D/A board. type, long and/or repetitive com- self-executing "Go To 10" func- mands. TSHORT saves consid- tion (line 10 may contain w 1 erable programming time—up to "RUN"). TSHORT includes the J VY» 90 percent—and, by providing 100 most popular and difficult Level II ELSE LEFT $( RIGHTS INK LINE percent accuracy, eliminates the BASIC commands such as programmer's biggest frustra- "RIGHT$(", "LEFT$(", "IN- tion—syntax errors. Immediately PUT", "LPRINT", "CLOAD", s D I |fn G | H after each single keystroke entry, "PRINTUSING", "GOSUB", GOTO the entire command is spelled out etc. GOSUB RETURN DEFUSR SYSTEM in its normal format on the moni- TSHORT comes on cassette- 7 tor and/or listing, i.e., there is no one side for Level II and the other X c V B code to interpret. for DOS. What really makes

TSHORT features a KUSTOM TSHORT easy to use is the set of GJ( STR$( CHR$( VARPTRI LENI key, changeable anytime, for user- pressure-sensitive decals (white let- defined functions up to 64 char- acters of instruction, as well as a fsee PRODUCTS, page 191) Keyboard with TSHOR T commands.

method to protect segments of a a protected program, then he ting. I do not think a system Overprotective? program while allowing modifi- should identify the fact so the should become a standard just cations of those areas that need to buyer knows what he is getting. because it has numbers. (Star- I want to comment on the topic be customized. Paul W. Sparks lings, blackbirds and crows are of protected programs. To put Also consider for a moment Gales Ferry CT not national birds.) I feel the mi- my remarks in context, I should what are the potential sources of crocomputer is headed for the mention that I am writing and program violation. I think that "back door," and that's a have programs for sale and have out-and-out plagiarism is mini- "10-4." Let's at least make this had articles accepted to be pub- mal, and there are legal means of "Whipping" POKE electronic machine a little more lished in current trade magazines. dealing with this. The major useful to society. Let's start inter- All this means is that I have some source or irritation lies with the When you append two or more facing with the real world! stake in the issue of copyright. No "make a copy for me" syndrome programs (see Roger L. Pape's Tim Ziller doubt I would be furious if some- between friends. This significant- "Whip File Wipeouts," July 1979, Grand Island, NB one copped my programs for his ly reduces the market for the au- p. 39), it may be necessary to add own and went into competition thor of the program. the step CLEAR:RESTORE in Tim, I can see you 're gonna just with me. I believe that this problem can the command mode if your mem- love my new magazine, 80- However, there is another side be minimized by good leadership ory size disagrees with what it MICROCOMPUT1NG. Oh, I of the coin that should be consid- in the user clubs and education of should be (add this step after re- agree with the need for gadgets to ered before we all go running off the potential users by editorials POKEing the start of the program permit our systems to reach out to put a lock and chain on our and letters such as this. I also pointer to its default value). and accomplish tasks such as lawn programs. I've never met a pro- think that this is the only solution In addition, it should be noted watering, feeding the English spar- gram that I have not wanted to because if someone is smart that the start of the program rows, scratching our back, replac- change to meet my own idiosyn- enough to protect a system, then pointer will not always be ing our aging mailman. Go take a cracies. Even more important is there is always someone else that 16548,233 and 16549,66. If 10-100, good buddy. —Wayne. that in this industry we have man- is just a little bit more clever who TRSDOS is up, for example, it will aged to develop a myriad of in- will find a way around the block. be 186 (LSB) and 104 (MSB). compatible systems . . . even Micros are just too simple. If you use someone else's disk with the same names. For exam- One final thought on the sub- system, or some newer or older ple, I could run a Cursor program ject. The development of Ameri- version than 2.2, PEEK these loca- designed for 8K memory on tape, can literature is based upon the tions without a program in the Greatly enjoyed "Murphy's but if that program was designed examples of the past. I feel that RAM and use those values. Keep Laws" (August 1979, p. 44). to use a cassette file system I'd much the same idea applies in the in mind that to PEEK or POKE Dzwonkiewicz's maxim: Nega- sure want to convert it to disk area of good programming. One above 32767 you must use the for- tive thinking produces negative files. I could not do that on a pro- learns from concrete examples of mula: - 1'(65536-desired ad- results. Positive thinking also tected program. successful programming on the dress). produces negative results. What about the differences— market. The plethora of books on Robin L. Salmansohn Dorsey F. Burk not trivial—between the 8K PET, beginning programming and the Abington PA Rancho Murieta CA the CMC and the new 16/32K dearth of any good material on graphics version? Although a lot advanced programming is readily can be done to program around evident. In my opinion, the wide- these differences, I doubt that we spread use of protected programs For the Birds Meet You in Philly will be able to ever get to write a will adversely affect the quality of "universal" program. I can't. our industry in the long run. I personally feel we are wasting I am involved in trying to de- In my mind there is no way to In conclusion, I think the au- our time and energy, especially in velop, for profit, microcomputer handle a good utilization pro- thors and publishers of programs printed form, for gadgets and applications for certain areas of gram without allowing for modi- should consider carefully the po games whether "hard or soft." the health-care industry, and I fications for a use peculiar to the tential impact of protected pro- I'm really upset about the enor- would like to establish communi- user, and that's what we are writ grams prior to utilizing that tech- mous press coverage some cheap cations with other individuals ing for. One solution may be a nique. At least if one is marketing systems, i.e., TRS-80, are get- and organizations who are inter- ested or involved in this particu- anyway. Again, many thanks to 8080 code. This is primarily due feel I was robbed! Almost any- lar area of microcomputer en- Dave Morr for making available to the index registers and bit one, novice or not, is going to deavors. Also, I am planning to his well-thought-out program, operations; although there are have a hard time with it. Your re- attend "Personal Computing and I hope that these tips may be lots of registers, memory opera- views should provide such warn- '79" in October in Philadelphia. 1 of value to some readers. tion capability has been signifi- ings! am hoping that I might get a cantly increased. While 8080code David F. Miller Kendal T. Rogers chance to meet some of these peo- must always shove data through Niles IL Fountain Valley CA ple while I'm there. In fact, I'm the single accumulator, I find proposing to get together during I want to commend you on that fewer than half of my Z-80 your continuing publication of I'd like some more opinions on that weekend in Philadelphia subroutines ever access the ac- this since most of the comments on such a group who, for now, I will excellent applications articles for cumulator at all. Because I the TRS-80. An an amateur-radio the book have been enthusiastic. call Health Care Microcomputer learned 8080 first, it took me Ken, aren't you blowing a few Entrepreneurs. operator, I was especially pleased months to learn to program that with the article by David Morr on minor things out of proportion? In addition to wanting to hear way, but now my subroutines are using the Baudot teleprinter for There are some really lousy books from anyone who is interested in faster and only half as long. TRS-80 hard copy. The software on the market; let's go after these. this area of activity and who ran nicely without modification, Furthermore, "Intel standard Readers, if you get suckered into wants to exchange correspon- except that I got no automatic mnemonics" are very confusing, buying a bad book, please do write dence, I would like to receive spe- CR-LF after 72 characters. and when applied to Z-80 op in so we can pass the word, but be cific indications of interest and codes, incomprehensible. sure you have it in perspective.— However, when I first entered intent from those individuals who Come on, people, teaching Wayne. it and then typed LLIST or would be interested in participat- 8080 code first is like teaching LPRINT, nothing would hap- ing in such a meeting during that people to cut their lawn with a pen. Then I discovered that the weekend (October 5-7). sickle before they can learn to use driver addresses were not loaded a riding lawnmower. It's a waste Plus and Minus Thomas H. Swalenberg at 16422 and 16423 decimal. I of time. HCSMS found that by adding the follow- Let me take this opportunity to PO Box 13089 ing BASIC statements: Richard Rodman Columbus OH 43213 Vienna VA thank you for a great rag—one POKE 15422,176 that is well worth the air-mail POKE 16423,1267 So write an article telling us how to postage to New Zealand. Thank OK, your letter has been pub- the program would function start writing Z-80 code, or at least you for the advice to jump in and lished. Now I expect you to keep properly. Keep up the good work, give a good reference to read on get my feet wet by buying some Microcomputing readers up to and how about some RTTY-ori- it. — Wayne. kind of micro even before I fully date on what develops. — Wayne. ented Baudot input-output pro- understood what was really going grams for the TRS-80? on. PS. I used Rod Hallen's The Movie Was Great . . . . I have been a computer "pro- More on Morr "Monitor" program from the fessional" for the last 11 years, June 1979 issue to load Morr's I purchased Rodnay Zaks' but am now learning things about Many thanks to Dave Morr for hex listing! Programming the 6502 on the computers I never knew. It is rea- his "TTY" program in the Au- basis of your review in the July A. Podolsky, M.D. sonably difficult to stay up with gust 1979 issue of Microcomput- 1979 issue. Your reviewer men- Oak Park MI the play at this distance, although ing (p. 38). The program is fast, tioned: "On the negative side, we have an active club here in and it makes BASIC listings very It is not Baudot code, it is Murray Zaks' book contains a lot of typo- Auckland. code (see June 1978, p. 4). Those readable thanks to the special graphical errors . . . most of Some U.S. vendors are much confounded Frenchmen have been symbols used in the printout. For them are trivial . . ." This is the more helpful than others. I'd like taking credit for this for too long. those of you who are using a 60 understatement of the year! This to put a plus by the names of Jade Murray was an American, and our wpm Baudot machine, as I am book contains not only "lots," and Personal Software, and a printers are and have been using (Teletype KSR-32), a couple of meaning hundreds, of trivial minus by the names of Commo- Murray code and not Baudot. Got changes that I've found success- typos, but is generally illiterate in dore and Ohio Scientific. ful might be of interest. it? Other than that, thanks for the English construction, (Example, additions and notes; any others Jim Kennedy As mentioned in the article, lo- on page 46, "Exercise 3.1: Close from other users of the system will Auckland New Zealand cation 7F93 must be changed; I now this book.") be appreciated. The whole idea of found that 24 hex was the right However, more important is this magazine is to allow comput- value for my machine. I also Zaks' lack of precise understand- erists to help each other— Wayne. found that, apparently due to the ing of the 6502. I thought I could speed of the program, reversing pick up some pointers on the 6502 Thanks the carriage-return and line-feed from this book, but it is so rife routines produced better results. Lawn Care by Computer with substantial errors that you Since your publication of my This involves changing 7EFD to must check every line if you really letter (July 1979 Computer Clin- 02 and 7F02 to 08. If you prefer a In "Machine-Language Moni- wish to use it. For example, on ic) asking for help in obtaining 64-character-wide paper printout tors for the TRS-80" (August page 219 he has the code: previous Popular Electronics ar- so that it will match the CRT of 1979, p. 114), author Robert Ed- ticles on the COSMAC Elf there has been a tremendous response the TRS-80, then change 7EA1 to monds recommends that persons ADC MOO RESTORE BIT from your readers, and I have re- 3F. To use the cassette motor learn 8080 code first because it is ROL CHAR SAVE BIT IN CHAR control relay for keying as shown a subset of the Z-80 code. ceived all the information need- ed, and more, on the COSMAC in Fig. 2 of the article, simply This is a common mistake; it After the ADC command, the Elf. Among your readers who change 7F88 to 14. arises because Zilog engineers carry will be clear. The ROL will sent copies of the Elf articles were Before running the TRS-80 for wanted to preserve compatibility always rotate a zero into CHAR Mr. Don Hartley, AR; Mr. John a hard-copy printout, make sure with existing software. However, so the bit won't be saved in Lund, IN, Ms. Joyce Weisbeck- that your TTY's carriage is re- the additions are not mere "en- CHAR! er, NJ; and Mr. Jeff Duntemann, turned and that the machine is in hancements." They comprise a If I buy a book, I prefer it to be NY. I would like to thank them the LETTERS mode. The pro- different logical architecture that mostly correct. Then I can learn for their enthusiastic help. gram does not print on the CRT is more elegant and efficient than from it and not always have to be screen when talking to the TTY, that of the 8080. Optimal Z-80 on the defense against minor and Moses Huang but this is very seldom needed code is structurally different than major errors. With this book, I Singapore Food for Thought

Someday, every child will benefit from computer-assisted instruction.

Why not give your child the head start he deserves?

.For the Apple* .For the TRS-80**.

Math Tutor I Math Tutor II Teacher

The Math Tutor I package is designed to Math Tutor 11 is designed to complement the This practical program allows you to input help younger children learn the concepts of Math Tutor I package and introduces students any number of questions and answers from the mathematics. It uses the technique of positive, to more advanced mathematical principles. fields of science, languages, history—you name immediate reinforcement. When the child Again, it uses the technique of positive rein- it. Using this data, the computer will prepare enters a correct answer, he or she is rewarded forcement by offering rewards for correct several types of tests, quiz students—providing with the opportunity to move a spaceship, cast a answers—a principle long recognized as effec- up to three hints per question—even offer magic spell, or rescue a man from a most unfor- tive in helping students develop healthy at- graphic rewards for younger children, all at the tunate fate. By using this method of positive titudes towards study. To keep pace with in- user's discretion. True or False tests may also be reinforcement, children will learn to associate dividual pupil's development, all of the pro- given. mathematics with pleasant experiences, as op- grams in this package may be used with any one Included with the Teacher package is a posed to the stark reality of numbers that has of four levels of difficulty. Package includes: separate program, Teacher Data transfer, that driven so many pupils to an early dislike of allows several tests to be recorded sequentially math. The program also provides the opportu- on one cassette, thereby permitting the ad- Car Jump nity for parents to indulge in a unique learning ministration of whole lessons without the in- experience with their children, while introduc- Make the car jump over the buses. Every convenience of loading individual cassettes. ing them to the exciting world of microcomput- time your student correctly calculates the areas Teacher is effective, practical, easy to use— ing. Teachers can also use the program in a of various geometric planes, the number of bus- perfect for teachers, parents, businessmen or classroom setting to provide that extra incen- es in the line is increased by one. anyone faced with learning a lot of material in tive. Math Tutor I contains the following pro- the shortest possible time. Furnished with blank grams: Robot Duel data cassette. Each time a student correctly answers a Order No. 0065R $9.95 Hanging question involving volumes of geometric solids, he's allowed one shot at the computer "robot." If your local Instant Software dealer A variation of the traditional game of Hang- For every incorrect answer, his shield power doesn't have the program you're looking for, man. In Hanging, students must spare the drops, and the enemy robot is given the oppor- you can order direct: Just use this order graphic character's "life" by correctly answer- tunity to shoot back. ing the questions posed by the computer. blank or call Toll-Free 1-800-258-5473. Sub Attack Spellbinder Students get to practice using percentages as The student is cast as a magician competing they maneuver their sub into the harbor. A cor- against another magician who's controlled by rect answer lets them fire their torpedoes at the the computer. He must answer the questions enemy fleet. Address about fractions correctly in order to cast magic Order No. 0098A $ 7.95 clouds, fireballs, and other spells at his rival. City Note: All programs in this package require Ap- State Zip Whole Space plesoft II BASIC. The student is given the opportunity to Check Money order lead an attack on an evil planet. Every time a correct answer is given to a math problem posed •Apple and Applesoft II are trademarks of Apple Compuier Inc. VISA AMEX Master Charge by the computer, he can move his ship closer to 'TRS-80 is a registered trademark of Tandy Corp. his goal. Every wrong answer gives the enemy Card No. an opportunity to fire back. Expiration Date Order No. 0073A S7.95 See page 71 for Signed Date Note: The Hanging and Spellbinder programs require Applesoft U BASIC. The Whole Space valuable coupon offer Order your Instant Software today! program can run in Integer BASIC. Quantity Order No Unit Cost Total Cost

As with all Instant Software programs, Math Tutor I & II and Teacher are sold complete with detailed instructions that take even the novice step by step, from loading and running the program, through suggestions for use and care of cassettes. i Handling $1.00

Total Order

Instant Software Inc. Dept. 69J3 Instant Software Inc. Peterborough. N.H 03458 USA Peterborough, N.H. 03458 603-924-7296 L. Phillip Schuman 1627 Woodcutter Wheaton IL 60187

Peter A. Stark PO Box 209 Mt. Kisco NY 10549

Thoughts on the SWTP Computer System

Part 6 of this series finds a coauthor, Phil Schuman. In this installment, Pete and Phil take a close look at three of the six disks that are available for the SWTP computer system.

here are six disk systems SWTP MF-68 system into an ware and the software. One is no allow you to flip a disk over and Tavailable for the SWTP SSB-compatible system that good without the other. More- use the back, some may move system at this time—three large will run SSB software. It costs over, there has to be good soft- the head from track to track a lit- floppy and three mini-floppy. $270. (With this kit, some drives, ware support; the world s best tle faster and some may have The large ones (Midwest Scien- a case, power supply and cable, hardware will do you no good more tracks. tific Instr., SWTP and Smoke you could build your own SSB- without a good selection of soft- The drive has to be mounted Signal Broadcasting) are more compatible system.) ware available. Let's talk about in a case and connected to a expensive and quite possibly Peripheral Technology Asso- the hardware first. power supply. Since the con- outside the reach of many. But ciates, 3848 Hampton Dr., Co- Mini-floppy disk systems con- troller board is powered by the the three minis are more rea- lumbus GA 31904, sells a disk sist of several parts. First, there mainframe, the power supply is sonably priced, and are the sub- controller, model FD-1, which is is the controller. This printed cir- only for the drive or drives. It ject of this review. They are: compatible with SWTP MF-68 cuit board contains the elec- mounts in the same case. There The LFD-400 from Percom software ($27 for a bare board, tronics for controlling the disk are small differences here Data Company, 211 N. Kirby, $110 for a wired controller). With drives and mounts inside the among the three systems. Garland TX 75042, at $600 for a this board you could change an computer. The SSB and Percom Percom's basic one-drive wired single-drive system or SSB or Percom system into one boards are large and fit into the system comes in a small case $1000 for a wired dual-drive compatible with SWTP MF-68 50-pin bus in the SWTP system, for just one drive; it has a small software. (Or, with your own system. next to memory or CPU boards. supply only capable of powering drive, case, power supply and The BFD-68 from Smoke Sig- The SWTP controller is a smaller one drive. A two-drive system cable, you could build your nal Broadcasting, 31336 Via Co- board that plugs into the 30-pin has a larger case and two power own.) linas, Westlake Village CA I/O bus. (If your system is supplies. Updating from a 91361, at $800 for a single-drive Likewise, Percom sells their already overloaded with boards single-drive system to a two- and has no empty slots in one wired, $1140 for a dual-drive controller separately for $115, drive system either results in bus or the other, your decision is system or $1480 for a triple-drive wired; using this you could two separate one-drive cases or made right here.) system. A less expensive single- modify an SSB or SWTP system requires an extra charge for a drive system ($650), called the into a Percom, or build your own. Then there is the drive. All of larger case. ABFD-68. comes without case The Micro Works, PO Box the commonly used drives, such The SWTP case comes with or power supply. 1110, Del MarCA 92014, offers a as the Shugart SA-400, Wangco two drives and a power supply The MF-68 from Southwest retrofit kit (model DM-85 at $40) model 82. Pertec or whatever, for two. (Expanding beyond two Technical Products Corp., 219 for combining 5-inch mini and are exact replacements for each requires a second case and W. Rhapsody, San Antonio TX 8-inch regular floppy drives on other. They have the same power supply.) It's not available 78216, at $900 kit, $1000 wired the same SSB disk controller. It mounting screws, the same con- with just one drive. for a two-drive system. only works with later controller nector and the same connec- The SSB case and power sup- boards. There are also several hybrids tions. You could mix two dif- ply are adequate for three among these systems. Smoke ferent drives in the same sys- drives, regardless of whether Disk System Hardware Signal sells an MF-68-U kit, tem, although there are good you buy the single, dual or triple which includes the SSB con- A complete disk system con- reasons not to do so. There are system. troller board, to change an sists of two parts—the hard- slight differences: Some drives Connecting the controller with the drives is a cable. Most The commands are groups of the SWTP system, the disk boot Western Digital 1771-01 floppy systems use a 34-wire flat cable programs that will perform is in SWTBUG; in the SSB sys- disk controller chip for disk for- with crimped-on connectors at selected functions, such as tem, it is in ROM on the con- matting and is fairly uncompli- both ends. In multi-drive sys- LOAD or SAVE, for the user. A troller board; in the Percom cated, with just 13 ICs. The tems, one end of the cable sim- basic set of commands is usual- system, the entire DOS is in 1771-01 chip does all the work; ply has two or three connectors, ly supplied with the system; ROM and does not have to be most of the other ICs are used separated by about 6 inches, some additional commands booted. just for buffering inputs and out- which connect the same cable may be available at extra cost, Another word to learn is IPL, puts. to all drives at the same time. and the user has the option to or initial program load. This is The bootstrap may be entered With the exception of three write his own commands in the logical sequence of bringing by hand, or you may use the disk wires in the cable, which select assembly language or add other a DOS up to a state of readiness. bootstrap in SWTBUG. DOS oc- a particular drive, all other wires software that will be treated as This may involve a booting, cupies 4K of RAM at addresses are shared among all three commands. along with any other housekeep- 7000-7FFF; in addition, certain drives. The monitor is that portion of ing functions, before the system FLEX commands require a large This makes the wiring simple, the system that will maintain is ready for commands. buffer area, and, therefore, the but has one disadvantage: control, prompt for and check Let's introduce another word system also requires at least When you read or write on one syntax of commands and inter- that will be used later. A diskette 12K of RAM starting at address disk, all the drive motors go on face to file-management rou- has a write-protect notch along 0000. This area is used fairly together. This lack of indepen- tines. The monitor is usually a one edge. When this notch is left seldom, however, and is other- dent motor control means that set of subroutines that may be uncovered, that disk is unpro- wise available for programs (such as to hold the BASIC inter- there is wear and tear on the accessed by the user (in assem- tected and can be written on. preter, for instance). unused drives and disks as well. bly language) by way of a But when a piece of tape is The disk drives and the Per- jump table, with an instruction placed over the notch, the FLEX has its own sophisticat- com and SSB controllers use such as JSR GETLINE or JSR system senses the tape and will ed terminal I/O routines and, 34-pin two-sided card-edge con- ERRMSG. not write on that diskette. Hence therefore, does not depend on nectors; the SWTP controller The file-management portion the diskette is write-protected— the ROM monitor to provide this uses an AMP 87365-4 pin-type is the set of routines and sup- protected from being written on. function. This means that any connector. Thus the same cable porting work areas that access With this introduction, let's programs you write should use could be used for either Percom the diskette for reading and look at each disk system one at the FLEX I/O routines, rather or SSB controllers, but another writing. In addition, a directory a time. than MIKBUG or SWTBUG I/O connector has to be installed if is maintained to ease in the routines. This is somewhat of a SWTP MF-68 it is to be used on the SWTP con- searching of the diskette for problem; FLEX contains equiv- alents of the INEEE. OUTEEE or troller. (By the way, the Radio specific files. The SWTP MF-68 consists of PDATA routines of the ROM Shack TRS-80 also uses a card- All of these components of a large cabinet with two drives, a monitor but does not have some edge connector, so the same the DOS may be resident in power supply, controller board, of the others you might use. drives and cable could be used memory, but usually the com- connecting cable, a DOS and such as OUT2HS or BADDR. on SSB, Percom and TRS-80 sys- mands and other low-usage rou- Disk BASIC. The DOS is called Hence, it may be difficult to tems.) tines are kept on the diskette FLEX and is written for SWTP by and only loaded into memory as Technical Systems Consul- work your way around it. Software Requirements needed. tants, Inc. (TSC, Box 2574, W. The system uses soft-sector Along with the hardware, you In addition, some DOS Lafayette IN 47906). Although diskettes, which have only one need some software. This is systems have other functions. only two drives are supplied, two index hole and therefore have to where the big differences really There is sometimes a set of rou- more can be added with an ex- be formatted before they can be are among various systems. As tines for terminal I/O, that is, for pansion kit. used. This is done by the DOS, far as the hardware is con- communicating with the ter- The controller plugs into port but requires several minutes for cerned, the three systems are all minal. For example, the SWTP 6 of the I/O bus in the main- each disk. differently designed and built, DOS has its own routines for frame. But it requires that a The FLEX disk operating sys- but basically all work equally communicating with the ter- jumper be placed across two tem is included in the price of well. For most people, it's the minal, while the SSB DOS uses pins in I/O slot 5. SWTP sug- the disk system (although TSC software that sways them from the MIKBUG or SWTBUG ROM gests that you pull out the is now supplying a more ver- one system to another. to perform the actual I/O. motherboard and solder the satile DOS called FLEX 2.0 on Disk software consists of two When the computer system is jumper underneath, but a much their own, at a price of $75). parts-the disk operating sys- first started, there must be some easier way is to simply plug a FLEX commands reside on tem, or DOS, which is the entire way of starting up the DOS. The few extra female Molex connec- the diskette. The system comes package of software used to SSB and SWTP systems keep all tors of the type used on the I/O with a basic set of commands. control the diskette, and the ap- of the DOS on the diskette and boards into slot 5 and connect Also, TSC has written additional plication programs, such as a require a mini loader to read the the pins on top. In any case, this ones and sells them at extra BASIC interpreter, assembler or beginning portions of the DOS jumper uses one of the user- cost, and commands can also editor, which are used with the into memory. Once enough of defined (UD) lines on the bus be written by the user. Any ex- DOS. the DOS is able to run, it loads and also makes it difficult to use ecutable file on the diskette may The DOS is the essential pro- the rest of itself into memory. port 5 for any other purpose be used as a command; FLEX gram that controls everything The function of reading the be- (since its select line is being will attempt to load and start ex- the disk system does. It is usual- ginning portions of DOS into used by the disk). Thus the con- ecuting any command entered ly broken down into three areas memory is called booting, and troller really uses up two I/O on the terminal. The command of responsibility: commands, the mini loader program is slots. names, therefore, do not have the monitor, file management. called the boot or bootstrap. In The controller uses the any special naming conven- tions. If, for example, you enter The first two commands are STARTUP.TXT, which can con- back data without errors. Any the word CLOAD, FLEX will look part of the DOS and sit in mem- tain a set of commands that will defective sector is automati- on the diskette for a program by ory all the time: automatically be executed as cally removed from the disk that name to execute. If the pro- soon as FLEX is booted. Hence, simply by not being linked in the GET—load a file into memory gram exists, it will be loaded and all the assigning of terminal out- chain of empty sectors. In this and return to FLEX. run. Hence, additional com- put, system disk, working disk way, the DOS can use a disk MON—return to monitor (MIK- mands, beyond the functions or other system parameters can even if it is not perfect. BUG or SWTBUG). that FLEX normally has, can be be automatically done at start- When a file is placed onto an easily added to the system. The remaining commands re- up or IPL. This is specially in- empty disk, it goes in the first side on the disk and are called FLEX prompts the user with tended for beginners or busi- empty available sectors, and + + + and uses control-H or into memory only when needed: ness users who don't want to be then the pointer in the directory some user-defined character as APPEND—merge two or more concerned with the nitty-gritty is updated to point to the first the back space. The control-X is files into one. of booting the system and get- empty sector beyond that. As a used to delete an entire line. A ASN—assign system and work- ting it going. disk is filled up, each file goes FLEX command called TTYSET ing disk drives. into the next empty sector in the controls these and other charac- BACKUP —create a mirror- FLEX Features chain. teristics of the terminal. For in- image copy of a diskette. FLEX maintains a directory At this point, there is one stance, TTYSET controls the BUILD—create a small text file. on each disk of the files that are linked chain of all the empty line length, whether the system CAT—list a directory of diskette stored on it. File names consist sectors; in the directory, there is echoes or does not echo char- on specified drive. of one to eight alphanumeric one pointer that points to the acters being input, and so on. COPY—copy selected files from characters (the first of which first of those empty sectors. This command sets the total en- one disk to another. must be a letter), followed by a Moreover, for each file on the vironment as far as the terminal COPYNEW—copy only those period and a three-character ex- disk, there is a directory entry is concerned. It even keeps files that do not already exist on tension, which specifies the that points to the first sector track of the number of lines the second disk. kind of file it is. For instance, used by that file. Each sector, in printed, so that output can be DELETE—delete a file from the commands have the extension turn, points to the next sector of separated into pages on the disk, erase its name from the .CMD; text files end with .TXT; that file. In both cases, the chain printer. A pause option allows disk directory and free up the BASIC source programs have an ends when the last pointer is the output to stop at the end of a space formerly used by it. extension of .BAS. 0000, indicating there is no page; hence, users with CRT ter- EXEC—process a text file as a The diskette is divided into 35 more. minals can set up the paging list of FLEX commands. tracks, and each track is further But when a file is deleted, its and pause so that FLEX will fill JUMP—start executing a pro- divided into 18 sectors. One name is erased from the direc- up an entire screen with output gram at a specified address. track is reserved for the direc- tory and its sectors are re- and then wait until the user has LINK—set a pointer to inform tory, with the remaining 34 leased, that is, their chain is read it before going on. the bootstrap program where to tracks holding a total of 612 sec- added to the chained link of Since the SWTP disk system find the FLEX DOS on the disk- tors. Each sector contains 124 empty sectors. Now when a new is normally supplied with two ette. data bytes, for a total usable file is added to the disk, it may drives, it has provisions for us- LIST—display the contents of a disk capacity of 75,888 bytes. start to use space that has been ing each drive for a different pur- text or BASIC file. But since the DOS has to be on released from previous dele- pose. Using the ASN, or assign, NEWDISK—format a blank disk- at least one disk, the first disk's tions. command, you can assign one ette with soft sectors. capacity is closer to 50-60K In an intelligent DOS, new disk as a system disk and the P—steer the following com- bytes; only the second and files will be placed into those other as a working disk. The sys- mand to use a parallel printer on following disks in a system will areas of the disk that are big tem disk will have the DOS, its port 7 instead of the terminal. generally have the full amount enough to hold them, if at all commands, BASIC interpreter, RENAME—change name of file. usable. possible; in a dumber DOS, they assembler or editor, while the SAVE—save a specified region Within a disk, sectors are will simply be placed into the working disk will have the data of memory on the disk and op- allocated dynamically. That is, a first sectors in the chain of files used by these programs. tionally assign it an execution given file may be spread out all available ones. FLEX uses the This has the advantage that you address so it can start ex- over the disk, not necessarily in latter technique, but either way, can write-protect the system ecuting when reloaded. adjacent sectors. When starting often there will be no single disk and protect it from acci- SAVE.LOW—used to save com- with a blank disk, a disk-for- place big enough on the disk to dental erasure by an errant pro- hold a new file. In that case, it mands that will be loaded into matting process numbers all gram, while leaving the working will get spread out among sec- the higher memory addresses sectors and chains them to- disk unprotected so it can be tors all over the disk. used by FLEX. gether. That is, the directory written on. TTYSET—set terminal charac- holds the address of the first This has several advantages teristics and environment. empty sector, that sector holds and disadvantages. Released FLEX Commands VERIFY—reread the disk after a pointer to the next empty sec- space is immediately available every write to check that there Here is a short summary of tor, and so on down the line. to new files, rather than empty were no disk errors. FLEX commands supplied with Each sector is chained or linked sectors being left here and VERSION—display the version the system. (There was an ex- to the next one. This is called a there, unused. (For instance, number of a specified com- cellent review of this DOS by linked list, which links together Percom's disk doesn't do this; mand. Mickey Ferguson in Kilobaud, all the empty sectors. when a file is deleted on the Per- BASIC—start the BASIC inter- October 1978, p. 72.) These com- While DOS is formatting the com system, its sectors are at- preter. mands are referred to as the disk, it is also checking each tached to the file just before it on the disk. They cannot be Utility Command Set, or UCS, or In addition, FLEX has provi- sector to make sure it has no used by other files until a PACK sometimes just as disk utilities. sions for a file called defects and can store and read program is run to pack all the assembly language. In this However, these are all func- through BFFF (which means used sectors together and close case, all diskette I/O functions tions not spelled out in the FLEX you may have to add one or two up all the empty holes.) Since are scheduled through a user- manual that comes with the disk more memory boards), thus files get spread out all over a created work area called a File system; you must purchase releasing all ol the lower 32K of disk, this evens out the wear on Control Block (FCB). An FCB is DOS Advanced Programmer's memory for user programs. the disk surface, rather than required for each file while it is Guide for $5 to learn how to use (Since FLEX is then in a new concentrating it at the begin- being used. Several routines are them. This manual describes area, old FLEX commands or ning of the disk. available in FLEX to assist the how to use disk I/O for assem- programs will have to be On the other hand, when files user in properly loading the FCB bly-language programs, but changed to work with it.) are spread out all over the disk, with the correct information. does not give any source listing The new TSC FLEX versions more time is needed to read and Once it has been properly of FLEX. Hence, you cannot go differ from mini FLEX in a num- write programs. For instance, it primed, it must be opened for beyond the standard techniques ber of important ways. First, the takes several times longer to I/O; after the I/O operations are as they are described in the new FLEX offers more storage load a large program from the complete, the FCB must be manual. No source listings of per disk. Instead of 18 sectors SWTP disk than to load the closed. FLEX or its commands are per track with 124 data bytes same program from the Percom These functions are request- available. each, the new FLEX formats the disk. Thus, it may be necessary ed by placing the appropriate FLEX is a versatile DOS and disk with ten sectors per track, to reorganize a FLEX disk occa- function code in the FCB and has an excellent collection ot with each track having 252 bytes sionally, if just to speed up the calling the FMS. The FMS rou- related programs available for it. of data. One track is reserved for access time. tines, in turn, will handle the The basic FLEX, which is sup- the directory, so that the remain- FLEX handles disk I/O with its disk-related I/O and process a plied with the SWTP disk system ing 34 tracks hold 340 sectors, File Management System character at a time for the user. at no charge, is called mini for a total of 85,680 bytes (in- (FMS). These routines are resi- This is convenient for the pro- FLEX, but even so it is quite a stead of the 75,888 bytes in mini dent in memory, accessed via a grammer. since most non-disk package. FLEX). New FLEX disks, therefore, have almost 13 per- jump table, and provide the programs operate with charac- TSC is now selling several cent greater storage capacity necessary functions to access a ter-at-a-time I/O and are easily other versions of FLEX, in- than mini FLEX disks, though file. adapted to disk for this reason. cluding FLEX 2.0 for the SWTP this becomes significant only BASIC and other application FLEX supports normal se- disk ($75), FLEX 2.0 for the when each file is relatively large. programs available for use with quential access, along with ran- Smoke Signal Broadcasting This is because a small file of. FLEX take care of reading and dom access. In addition, space mini-disk ($90) and FLEX 1.0 for say, 120 bytes takes up one sec- writing disk files automatically. compression and other special full-size Smoke Signal disk. The tor in both systems; but in the But it is also possible to use the options are available, if re- new FLEX systems require 8K of 124-byte sectors of mini FLEX it disk for programs written in quested in the FCB. memory from address A000 6800 SYSTEM SOFTWARE Unmatched • Field Proven • Documented • Industry Wide

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K* Reader Service—see page 227 Microcomputing, October 1979 33 wastes only four bytes, whereas time with a QCHEK command. printing to be overlapped with which is an important feature. If in the 252-byte sectors of the QCHEK can also be used to the main program itself, by us- you want to keep a file secret, new FLEX it wastes 132 bytes. delete individual files from the ing a buffer area in memory and you can also prevent it from be- Since each sector contains queue, or an XOUT command interrupts to allow the printer to ing listed in a catalog printout. twice as many bytes in FLEX as can delete all files that have an run at the same time as the com- Some other minor differences in mini FLEX, a given file will .OUT extension. puter processes data. This is an- are that some disk-resident contain only half as many sec- Printer spooling is a tech- other approach to the problem; commands, such as BACKUP. tors. One reason for the slow nique commonly used in large FLEX may work out better in COPYNEW or MEMTEST, don't speed of FLEX is that after every computer installations, and this some cases, INDEX may be bet- come with the new FLEX, or that sector is written, FLEX waits for is a first in the microcomputer ter in others.) if a file is not found on one of the drives, FLEX will look at the the disk to turn around and then area. But it also introduces The new FLEX differs from other drive. reads the sector to make sure some problems. For instance, if mini FLEX in several other ways. there are no errors. Since the program output is going to a For example, a disk is assigned What about other software? new FLEX contains only half as disk, what happens if the disk a name when it is first initialized With mini FLEX, as part of the many sectors in a given file, this becomes full? Furthermore, if (though there is no mention in system purchase price, you get process takes only half as long. the program whose output is go- the manual of the name ever be- SWTP Disk BASIC Version 3.0. Thus the new FLEX is faster ing on disk also happens to be ing used for anything). Files can This is essentially SWTP 8K than mini FLEX. using the same disk for files, the be protected from being delet- BASIC, which has been modi- A major feature of the new running time may be appre- ed, renamed or written over. fied to work with the disk. The FLEX is printer spooling. This is ciably lengthened by the need especially useful for running for the head to move from track BASIC programs that require ex- to track. tensive—and slow—computa- Since the print queue may Listing 1. tion, combined with long print- contain several different files to NAN FLEX-ISC EDITOR OPT TAP,NOG outs. Basically, spooling takes be printed, there will often be a • t************************* printer output and stores it back need to stop the printout be- • • FLEX TSC/EDI TOR • on the disk as a file, at high tween files to change to a dif- • •••». FLEX-FNS FUNCTION CODES **»•* 0000 10 EQU 0 CALL FOR 1/0 speed, instead of printing it. At a ferent kind of paper, move to the 0001 READ EQU t OPEN FOR READ later time, while running another top of a new page or make some 0002 UR1TE EQU 2 OPEN FOR URITE 0004 CLOSE EQU < CLOSE FILE program whose output is also other adjustments. Unfortunate- • • ***• FCB LAYOUT **•«• 0000 XFC EQU 0 FCB'O FUNCTION CODE going on disk, the first pro- ly, FLEX doesn't appear to have 0001 XES EQU t FCB+1 ERROR STATUS a convenient way of inserting a 0003 XUN E0U 3 FCB*3 DRIVE NUHBER gram's output can be printed 0004 XFN EQU 4 FCB+4-11 FILE NANE from the disk file at the same wait into its queue. OOOC XEN E0U 12 FCB»12-14 EXTENSION NANE 0001 TXT ESU 1 'TXT- F0RI1AT time. In this way, the program If there is a lot of printing to 003B XCN E0U 59 FCB»59 C0KPRESS FLAG 0000 XON EQU 0 CONPRESSION ON can continue running at top be done, the disk may be on for a 00FF X0FF EQU IFF COHPRESSION OFF speed without waiting for the long time during the printing; be- • **••• FLEX-FNS ENTRY POINTS »•»•• 7803 FNSCLS EQU <7803 FNS CLOSE printer, while the printer can run cause of the design of the SWTP 7806 FNS EQU 17806 FNS CALL ***** « FLEX: ROUTINES continuously without waiting controller, the motor will run 7103 UARNS EQU • 7103 FLEX UARrt START for the program. Essentially, two continuously during an extend- 7115 INBUFF EQU 17115 INPUT DATA INTO LINE BUFFER 7127 GETFIL EQU 17127 LOAD FCB FRON LINE BUFFER things go on at the same time. ed print session. During an hour 71 2D SETEXT EQU 1712D SET FILE EXTENSION 7I3C RPTERR EQU I7I3C REPORT DISK ERRORS (The MP-T timer has to be in- of printing, the disk will make 7118 PSTRNG EQU 171 IB PRINT STRING ENII IN 104 stalled in the computer to use 18,000 revolutions; most disk 71 IE PCRLF EQU I7IIE PRINT CR AND LINE FEED 1 rlL.IIPt rCfl Uhf the spooling feature.) and drive manufacturers specify 1491 ORG 11491 1491 CE 15 0E OR LDX •FCB POINT TO OUR FCB There is another use for disk life as two or three million 1494 86 01 LDA A BREAD CODE FOR OPEN READ revolutions, but 18,000 revolu- 1496 A7 00 STA A XFC,X STORE FUNCTION CODE INTO FCB spooling. It is possible to run a 1498 BD 78 06 JSR FNS CALL FLEX FNS program, store its output on tions in one hour is still a large 149B 26 59 BNE ERR BRANCH IF OPEN ERROR 1 49D 86 00 LDA A 110 CODE FOR 1/0 PROCESSING disk, and then examine that out- number. I49F A7 00 STA A XFC,X STORE FUNCTION CODE INTO FCB MAI 39 RTS put on a CRT terminal before Finally, printer spooling 1t trif1L et rcn UKu deciding whether to print it or would be a much more valuable I4A2 CE 15 0E 0U LDX •FCB POINT TO OUR FCB 14A5 86 02 LDA A IURITE CODE FOR OPEN URITE not. This avoids a waste of feature if there were some provi- 14A7 A7 00 STA A XFC.X STORE FUNCTION CODE INTO FCB 14A9 BD 78 06 JSR FNS CALL FLEX FNS paper—and time—if a pro- sion for a second printer. (In- MAC 24 48 BNE ERR BRANCH IF OPEN ERROR gram's results are not exactly cidentally, it is designed for a MAE 86 00 LDA A 110 CODE FOR 1/0 PROCESSING 1 4B0 A7 00 STA A XFC.X STORE FUNCTION CODE INTO FCB what is wanted. parallel printer in port 7, not for 14B2 39 RTS TCD1 tnniPlWH T MAIL To implement printer spool- the terminal.) MB3 BD 71 IE ASK JSR PCRLF PRINT CR AND LINE FEED (Percom's INDEX DOS takes I4B6 CE 15 CE LDX IASKNSG POINT TO OUR '? NESSAGE ing, the new FLEX has several 1 4B9 BD 71 18 JSR PSTRNG FLEX STRING OUTPUT RTN new commands. The 0 com- another approach. Program out- 14BC BD 71 15 JSR INBUFF INPUT RESPONSE INTO BUFFER MIF CE 19 0E LDX HFC! POINT TO OUR FCB mand is used to specify that the put can be routed to the disk, as 14C2 BD 71 27 JSR GETFIL LOAD FCB UITH DATA FRON BUFFER in the new FLEX, but its printing 14C5 25 09 BCS SERR BRANCH IF SYNTAX ERROR output of the following program 14C7 CE 15 0E LDX •FCB POINT TO OUR FCB is to go to disk with an .OUT ex- at a later time cannot be over- MCA 86 01 LDA A ITXT CODE FOR TXT' MCC BO 71 2D JSR SETEXT SET EXTENSION NAME tension. After the output is on lapped with other processing; it MCF 39 RTS MD0 BD 71 IE SERR JSR PCRLF PRINT CR AND LINE FEED the disk, the PRINT command is would have to be handled as a MD3 CE 15 D7 LDX •SYNTAX POINT TO ERR NSG used to instruct FLEX to put that separate job all by itself. This MD6 BD 71 18 JSR PSTRNG OUTPUT SYNTAX ERR NSG MD9 20 DS BRA ASK GO ASK FOR IT AGAIN program in a spooling queue to provides the option of examin- )1/UDTT/ UK 1 1C t Cll3 U MDB FF 15 E5 RU STX XSAVE SAVE X-REG be printed when its turn comes. ing output before printing, but MDE F7 15 E4 STAB iSAVE SAVE B-ACCUH The status of programs in the doesn't save the time that FLEX queue can be checked at any does. Instead, INDEX allows the 5AVE, LOAD and APPEND com- not allow random files, a big The new FLEX 2.0 includes FLEX routines used, along with nands of BASIC allow saving limitation to some users. the text editor, assembler, ad- information concerning the ind loading BASIC programs on Having written FLEX. TSC is vanced programmer's manual FCB. The next segments of soft- he disk; cassette commands the biggest force behind other and documentation as part of ware show the open file, close ire now TSAVE, TLOAD and systems and application pro- the price, so that if you plan to file, prompt for file name and TAPPEND. grams available for it. They have purchase these, the improved common I/O routines. These In addition, BASIC allows se- an excellent text editor ($31.50 FLEX package is a better deal. new segments are added to the quential data files on the disk. A for the disk version) for prepar- On the other hand, programs editor software and referenced jisk file is opened with an OPEN ing text and program files, an that run under mini FLEX require by some patches to the editor ;ommand, which ties a BASIC assembler ($31.50), a text pro- changes to make them run pointers. At the end of the listing iile number with a specific cessor ($40). a debug package under the new FLEX; in some are the patches that reset the lamed file on the disk. Subse- ($43). a package of disk utilities cases major changes may be pointers within the editor to quent READ, WRITE and RE- ($100). a disk sort-merge pack- needed. Furthermore, the new reflect the newly added disk STORE statements read or write age ($75) and even a super-fast FLEX price does not include a software. Dn the file and can reset it to the BASIC interpreter ($50), which is BASIC interpreter; the new TSC A certain sequence of events beginning, in a sequential claimed to be the fastest BASIC super-fast BASIC in the new must take place to properly ac- fashion as if the data were going on any 8-bit micro yet. But it only FLEX 2.0 form costs $55 (and in- cess a disk file. Before the FCB has sequential files, not random to tape. When data is done, you cludes random disk files). is opened, it must be loaded files. close the file. This BASIC does Other FLEX-compatible soft- with the correct information. ware is available from Com- The proper file name, with op- puterware Software Services tional extension and drive number, must be set into the 1 (830 First Street. Encinitas CA 14EI CE 15 0E LDX IFCB POINT TO OUR FCB FCB. This was done using the I 4E4 80 78 06 JSR FNS CALL FLEX FMS 92024) and includes a PILOT in- 14E7 26 07 BHE RERR CHECK FOR 1/0 ERROR. OR EOF FLEX INBUFF routine to accept 14E9 FE IS E5 L0X XSAVE RESTORE X-REG terpreter, and various games data from the terminal, placing I4EC F6 19 E4 L0« B BSAVE RESTORE B-ACCUM and utility programs. I4EF 39 RIS it in the line buffer. The FLEX • COMMON ERROR REPORTER ••»»• Ed Smith's Software Works UFO A6 01 HERD IDA A XES.X RETRIEVE ERROR CODE routine GETFIL is then used to I4F2 81 08 CBP A NOG CHECK FOR EOF C0DE*08 (PO Box 339. Redondo Beach parse the line and load the FCB MF 4 27 09 BED EOF IF FOUND. EOF— ELSE ERROR CA 90277) also has FLEX soft- I 4F6 80 71 3C ERR JSR RPTERR PRINT DISK ERROR CODE with the data that it finds in the I4F« 80 78 03 JSR FNSCLS CLOSE ALL OPEN FILES ware, including a macro-assem- 14FC 7E 04 41 JNP EDIT GO BACK TO EDITOR PROGRAM line buffer. The SETEXT routine 0441 EDIT EQU 10441 PRINT '?' AND EDITOR PROMPT bler, disassembler, trace/debug is then used to specify an exten- I READ EOF ROUTINE package and others. A PILOT in- 1458 READ25 EQU <1458 RETURN TO PROCESS READ sion of TXT. The file is now 1 444 REA04 EQU 11 464 EOF HAS SEEN READ terpreter is also available from I4FF 86 04 EOF LDA A ICL0SE CODE FOR CLOSE FILE capable of being opened by a ISOI A 7 00 STA A XFC.X STORE FUNCTION CODE INTO FCB SWTP. 1503 BD 78 06 JSR FNS CALL FLEX FMS call to FMS. After the file is pro- A BASIC renumbering pro- 1306 26 EE BNE ERR BRANCH IF ERROR ON CLOSE cessed. it must be closed by a 1508 FE 15 E5 LDX XSAVE RESTORE X-REG gram for FLEX BASIC version 1501 7E 14 64 JNP READ4 CONTINUE UITH 'EOF' PROCESSING call to FMS. > CONSTANTS AND TERMINAL MESSAGES »•»•• 3.0 is available from Lehigh I50E FCB RUB 192 192 BYTE BLOCK FOR OUR FCB Once the file is closed, the I5CE 46 ASKNS6 FCC -FILE? ' Computer Works ($10, 1132-2 15D6 04 FCI 4 Tilghman. Allentown PA 18102). FCB may be used for any I/O to 1507 S3 SYNTAX FCC SYNTAX ERROR I5E3 04 FCB 4 Microware Systems Corp. (PO any tile. In this case, only one I5E4 BSAVE RNB 1 SAVE B-ACCUM FCB is used for both reading I5E5 XSAVE RNB 2 SAVE X-REG Box 4865, Des Moines IA 50304) 15E7 00 FCB <0D SET BEGINNING OF EDITOR BUFFER also sells mini FLEX software, and writing of the edit buffer. I5E8 BUFFER EQU • USER BUFFER AREA > OVERLAY OLD CODE, including their A/BASIC com- 020C ORG I020C I/O VECTORS SSB DOS-68 020C 7E 14 08 JNP RU READ ROUTINE piler ($150) and related inter- 020F 7E 14 DB JNP RU URITE ROUTINE preter and debugging software, Like the SWTP system, the 0212 4F FF FOB «4FFF •••• SET MEMORY LIMIT •••» a LIST interpreter, as well as a SSB system consists of a cabi- 0272 0R6 •0272 COMNAND TABLE 0272 04 41 F DB • 0441 GAP IS NOV INVALID chess program and Eliza, a fas- net, power supply, controller cinating computerized psychia- board, cable, a DOS called 0358 ORG •0358 0358 CE 15 E8 LDX •BUFFER POINT TO OUR NEU EDITOR BUFFER trist program. DOS-68 and Disk File BASIC.

0988 ORG •0988 'EXIT COMMAND The cabinet and power supply 0988 7E 71 03 JNP UARNS GO BACK TO FLEX Advanced FLEX Programming can handle up to three drives,

1303 ORG 11303 URITE COMMAND Example and the system can be bought in 1303 80 14 83 JSR ASK ASK FOR OUTPUT FILE NAME 1306 80 14 •2 JSR ou OPEN FILE FOR OUTPUT An example of using FLEX one-, two- or three-drive ver- 1309 01 NOP FMS and monitor routines is sions. I3F5 ORG

I46F ORG <1 46F DEVICE CONTROL but this version was adapted by controller in this case is a large 146F 01 FCB 1,1,1 3 NOP S FOR DEVICE CONTROL Phil for users who already have board that plugs into the 50-pin the cassette version). bus, like a memory or CPU The beginning of the listing board. Hence, it does not use up shows the entry points into the I/O slots. The hardware design of the empty sectors. File space is teresting point is that, although The BASIC disk commands controller is quite different from allocated dynamically, and free Smoke Signal Broadcasting include FLIST for listing the files that of the SWTP controller. The or available sectors are allocat- doesn't say so, this is Com- on the disk, FDEL for deleting a SWTP controller relies on a ed as needed, so the disk need puterware Software Services' file, FREN for renaming a file. bootstrap program in SWTBUG not be repacked to combine Super BASIC. It has every fea- SAVE, LOAD and APPEND for (which does not always work empty sectors (unless it is ture that we have gotten used to saving and loading programs on well the first time); the SSB con- desired to speed up the system). with SWTP cassette BASICs, the disk and CHAIN for having troller has the bootstrap pro- DOS-68 has a set of com- plus a few new ones: a STRING one BASIC program call anoth- gram and some other I/O rou- mands that are part of DOS and command allows the string er. It also supports sequential tines in a 512-byte ROM on the always in memory and an addi- length to be changed; HOME disk files (which has caused controller card; so it can also be tional set of disk-resident com- issues a home-up and erase confusion among some readers used with other monitors. mands (called transients) that command for CRT terminals; who thought, based on SSB The controller design is in- reside on the disk and are load- SKIP skips lines on the terminal; advertising, that random files teresting in other ways too. In a ed into memory only as needed. WAIT inserts a time delay; were also supported). typical SWTP system, I/O ports 0 These include four memory- RJUST allows neater printout of File commands include OPEN through 7 use the 32 addresses resident commands: columns of figures by allowing and CLOSE, READ and WRITE, from 8000 through 801F. Ad- CLOSE—close all open disk decimal points to be lined up. RESTORE (for resetting a file dresses 8020 through 803F are files. left unused for those users who EXIT—return to the monitor. want to add a second mother- GET—load file into memory and board to provide eight more I/O return to DOS. Listing 2. ports. But because of incom- RUN—load file into memory and NAN SSB-TSC EDITOR OPT TAP,NOG plete I/O address decoding, the execute it if applicable. addresses from 8000 through It also has the following disk- • • SNOKE SIGNAL TSC/EDITOR « 801F are also decoded as 8040 resident commands: ' SSB-•DFN FUNCTION through 805F, 8080 through 0001 QS04U EQU 1 OPEN FOR URITE LIST—list the directory of a 0002 QSURIT EQU 2 URITE DATA 809F and so on, all the way up 0003 OSUC EQU 3 CLOSE FILE FOR URITING specified diskette. 0004 QS04R EQU 4 OPEN FOR READ through 8FFF (or 9FFF in the SAVE—save a specified region ooos QSREAIl EQU 5 READ DATA older motherboard). The SSB 0006 QSRC EQU 6 CLOSE FILE FOR READING of memory and an optional > FCB controller interleaves its ROM starting address. 0000 XFC EQU 0 FCB+0 FUNCTION CODE 0001 XES EQU 1 FCB«I ERROR STATUS RETURNED TO USER bootstrap and I/O routines into GETH—load disk files created 0002 XUN E0U 2 FCB+2 UNIT NUNBER the empty spaces between the 0003 XFN EQU 3 FCB«3 FILE NAHE in MIKBUG punch format (S113 0009 XEN EQU 9 FCB*? EXTENSION NAflE I/O ports. That is, there are 32 ...) from assembler or patches. OOOC XFT EQU 12 FCB»12 FILE TYPE > SSB--DFN ENTRY POINTS • «•»• bytes between 8020 and 802F, DELETE—remove an entry from 7780 0DFN EQU 17780 INI T OF DFN another 32 bytes from 8060 7783 CDFH EQU <7783 SSB-D0S CLOSE ALL FILES the directory and release the 7786 DFN EQU 17786 SSB-IfISC FILE NANAGER through 807F and so on, all the space allocated to that file. 7283 ZUARNS EQU 17263 SSB-D0S UARn START SSB-INPUT STRING INTO LINE BUFFER way up to 83FF. This is a novel 72B5 ZLINEI EQU <72B5 RENAME—change the name of 7291 2FLSPC ESU <7291 LOAD FCB FRON LINE BUFFER way to sneak in some ROM into 72A9 ZTYPDE EQU <72A9 TYPE OUT ERROR MESSAGE a file. • NIKBUG ENTRY POINTS »«••• the system without interfering in E07E PDATAI EQU CONSTANTS AND system can also be used in 1514 FCS RNB 166 166 BYTE BLOCK FOR OUR FCB are the patches that reset the 0441 EDIT EOU 10441 PRINT 'V AND EDIT PROMPT assembly-language programs. 1514 00 ASKNSG FCB <0, OVERLAY OLD CODE, 020C ORG •020C I/O VECTORS vanced programmer's manual, addresses. The ZLINEI routine 020C 7E 14 DA JNP RU READ ROUTINE the SSB DOS-68 manual is much 020F 7E 14 DA JNP RU URITE ROUTINE is used to accept data from the 0212 4F FF FOB • 4FFF ...... JET NEM0RY TO BE USED more detailed and also lists the terminal and store it into the line

0272 ORG •0272 COMMAND TABLE information needed by ad- buffer. The monitor routine 0272 04 41 FOB •0441 GAP IS NOU INVALID vanced programmers. ZFLSPC is used to parse 0359 ORG •03S8 The diskette is maintained by through the buffer and load the 0318 CE IS EO LDX •BUFFER POINT TO BEGINNING OF USABLE MEMOR a disk-file-management set of FCB with the proper informa- 0981 ORG <0988 EXIT COMMAND 0988 7E 72 83 JNP ZUARMS GO BACK TO SSB DOS routines. They are accessed via tion. The extension must be a jump table that supplies entry loaded by hand, as there is no 1313 ORG 113113 URITE COMMAND 1303 ID 14 83 JSR ASK ASK FOR OUTPUT FILE NAME points for various file-handling routine to perform this function. 1314 ID 14 A2 JSR 0U OPEN FILE FOR OUTPUT 1309 01 NOP functions. These include open- In addition, the files are stored ing and closing files, reading, as memory image binary, rather 13FA ORG • 13FA URITE EOF I3FA CE 15 14 L0X •FCB POINT TO OUR FCB writing and several other special than compressed ASCII. I3FD 86 03 LDA A «0SUC CODE FOR CLOSE URITE SEQUENTIAL 13FF A7 00 STA A XFC.X STORE FUNCTION CODE INTO FCB I/O requests. As you can see, though the 1401 ID 77 86 JSR DFN CALL SSB-DFN Like the SWTP disk, all file DOS-68 and FLEX systems are 1404 27 03 BE0 11 IF OK, RETURN 1404 7E 14 EF JNP ERR IF NOT. REPORT ERROR functions are channeled different, they are set up in 1409 39 12 RTS through a user-created work similar ways. Thus, any soft- 1420 ORG II42D READ COMNAND 1420 80 14 83 JSR ASK ASK FOR INPUT FILE NAME area called File Control Block ware created for one system 1430 80 14 91 JSR OR OPEN FILE FOR INPUT (FCB). An FCB is required for should be fairly easily modified 1433 01 NOP each active file the user is ac- for the other. 1454 ORG • 1454 READ EOF 1454 7E 14 F8 JNP EOF 00 TEST FOR EOF cessing. This area acts as an in- Next month, we will examine terface to DFM to communicate the features of the Percom 146F ORG • 146F DEVICE CONTROL CHARACTERS 146F 01 NOP the user's request for I/O. The LFD-400 disk system and con- 1470 01 NOP NOP OUTPUT OF TURN-OFF CHAR 1471 01 NOP DFM routines, in turn, use it as a clude this two-part article by buffer to hold data, letting the weighing the advantages and END user access a character at a disadvantages of each of the time. Several routines are three systems. • Software for the APPLE II FORMAT

PROGRAMMA's FORMAT (Version 1.0) is a command oriented text processor de- signed to be fully compatible with PIE (PROGRAMMA Improved Editor).

MLKTIUf I1ZII Of Til HIM riMKTI FORMAT'S system of imbedded commands (within the text) give it an ease of oper- ation similar to text formatters found on THE PLANETS S15.95 SAUCER WAR $15.95 some mini-computers.

FORMAT features right margin justifi- cation, centering, page numbering, anda auto-paragraph indent.

The following commands are available in with FORMAT:

.ad Begin adjusting right margins .bp n Begin page numbered n .br Cause a line break .ce n Center next n lines without fill ACTIVE FILTERS $24.95 .fi Start filling output lines .fo t Foot title becomes t .he t Head title becomes t .in n Indent n spaces from left margin

tttttttt TEAM STANOINCS SSSSSStS .Ii n Literal, next n lines are text AHERICAH-1 NATIONALS .II n Line length including indent is n TYPE COOE »72 EflST-l CEHTRALa2 HEST-3 .Is n Set line spacing to n TYPE COOE tTJ .ml n Top spacing including head title ii i l ,m2 n Spacing after heading title 8®r i 1 s n Spacing before foot title OO YOU MONT K»E ST«T$<»/»>? I .m3 ,m4 n Bottom spacing including foot title corvticNT it» .na Stop adjusting right margins .nf Stop filling output lines FOOTBALL PREDICTIONS S19.95 BATTLESTAR I $15.95 •Pi n Page length is n lines • PP n Begin paragraph= .sp, .fi, .ti n .sp n Space down n lines, except at top .ti n Temporary indent of n jfJffiJH riT •ill n Underline next n input lines

All orders include 3% postage and handling. Apple II is a registered trademark of Apple Computer, Inc. California residents add 6% Sales Tax STATE CAPITALS $9.95 LUNAR LANDER $9.95 VISA & MASTERCHARGE accepted.

PROGRAMMA INTERNATIONAL, Inc. 0 3400 Wilshire Blvd. Los Angeles, CA 90010 a (213) 384-0579 c M 384 1116 n 384-1117 P48 camion im ct SPEEDWAY $15.95 JOY STICK $49.95 Dealer Inquiries Invited EXPAND-A PORT $49.95 in T T T

DS-68 DIGISECTOR UIO UNIVERSAL I/O BOARD INNOVATIVE PRODUCTS FOR 6800 USERS

DS-68 DIGISECTOR is a random access video digit- DM-85 DISK MIXER is an add-on board for the izer featuring 256 x 256 picture element scan and Smoke Signal Broadcasting BFD-68A Disk Con- 64 levels of grey scale, with conversion times as low troller which allows operation of both 8" and 5" as 3 microseconds per pixel. It accepts either inter- drives. Controller mode (8" or 5") is selected on a laced (NTSC) or non-interlaced (industrial) video drive-by-drive basis, so any mix of 5" and 8" drives is input. Use it for computer portraiture, moving target allowable. The 2" x 3" PC board mounts incon- indicators, precision security systems, fast to slow spicously on the back of the BFD-68A. Its operation scan conversion.. .with clever software, the Digi- is completely transparent to software. An oscillo- sector can read just about anything. Truly a pro- scope is required for the setup procedure. Kit Price: fessional tool at a price you can afford. $169.95 $39.95

M6809 EMULATOR is a machine language program B-08 2708 EPROM PROGRAMMER is a compact uni.i+tt • M£ that fits in the 6800's I/O slot. A safety switch and that will emulate all of the functions of the Motorola LED indicator provide control over the high pro- 6809 third generation microprocessor. Developed gramming voltage generated on board. An industrial for use on any 6800 system, the program allows soft- quality Textool socket and extended board height ware development and debugging. The 3K byte pro- allow effortless PROM insertion and retrieval. Fully gram is complete with a 6809 mini-monitor and commented source listings of U2708 is included in single-step trace routines. Fully commented source the Owner's Manual. $99.95 listing included. Specify Smoke Signal Broad- casting or FLEX™ disk, or KCS cassette. $49.95 U2708 utility for testing, burning, verifying and copying 2708s in EPROM. $29.95

PSB-08 PROM SYSTEM BOARD features 1K of higrth UIiO UNIVERSAL I/O BOARD helps you with your speed, low-power RAM and space for up to 8 2708 custom interfaces. It has space for a 40-pin wire EPROMs, both DIP-switch addressable to start on wrap socket into which you may plug any of any 8K boundary in memory. The exclusive I/O Motorola's 40 or 24-pin interface chips. All data and select feature allows you to move I/O locations up to control lines are connected to the appropriate edge any unused 1K block in the EPROM memory space. connector pins. All other bus connections are This permits memory expansion to a full 56K of brought out to a 16-pin socket pad. + 5 volt regulator contiguous user RAM. $119.95 and all Molex connectors are provided; regulated + 5 and ground are bused among the locations for up to 35 14-pin ICs. $24.95

P.O. BOX 1110, DEL MAR, CA 92014 714-756-2687

is* Reader Service—see page 227 Microcomputing, October 1979 39 PAIA 8700 Revisited

Back in August 1979 (p. 94), Rod presented an overview of an under-200 computer, the PAIA 8700. This time, he's going to cover a specific application for the 8700: making music.

Rod Hallen possible uses. In this article I'll thing else I've ever written. control an organ or a synthe- Road Runner Ranch explore one particular applica- Therefore, the first thing I tried sizer allows you much more PO Box 73 tion. to do with the 8700 was make freedom of expression. After Tombstone AZ 85638 Computer music seems to be some music. some experimentation I de- a popular subject. I received cided on this second method. Generating Computer Music n a recent article describing more phone calls and letters as Since I didn't have a synthe- Ithe PAIA 8700 computer, Au- the result ot my computer mu- There are two general meth- sizer, I first had to build one. I gust 1979, p. 94,1 touched on its sic article ("Music, Music and ods of generating music with a ordered the Top Octave Experi- physical characteristics, op- More Music," Kilobaud, No- computer. First, the processor menter's kit from PAIA to use erating techniques and some vember 1978, p. 82) than any- can switch one of its external as a starting point (see Table 1). leads on and off at an audio I also sent for the cassette in- rate. When amplified, this is terface option kit and enough sound; if done right, it is also RAM to fill up the board. The music. The second way is to 8700 comes with 512 bytes of use the computer to control an RAM with space on the board electronic organ or a synthe- for another 512 bytes for a total • 12 [ l 16 1-478 sizer of some kind. of 1024. This RAM is addressed CLOCK[ 2 IS ) + 239

6ND [ 3 14 1 + 253 The late, great "Music Sys- from 0 to 03FF hex. - F • 451 [ 4 13 1 + 268 tem" from Software Technolo- I quickly installed the cas- - F# ^426[ 5 12 1-284 gy is an example of the first sette kit, which worked the first 6 II + 402 [ 1 + 301 method. It has the advantage time. A bonus of the cassette • 379 [ 7 10 1 + 319 that it is easy to use and that no + 358 [ 8 9 1-338 option is a solid-state sounder 50240 external hardware other than that beeps whenever a key is an amplifier is required. In fact, touched. It also allows you to when not much volume was hear the recording and play- needed, I drove a small speaker back of your programs. Dou- directly with TTL logic. The dis- bling RAM to 1K required in- Fig. 1. A pin-out drawing and a block diagram of the Mostek 50240 advantage of this method is the stalling four IC sockets and top octave generator. Inputs are + 12 volts, ground and a clock. limited control of the type of four 2112s ICs. Outputs are 13 equally tempered semi-notes making up one octave sound produced. On the other The top octave kit contains a plus one note. hand, using the computer to small PC board, a 4001 CMOS IC and a Mostek 50240 top oc- tave generator. The latter is ac- tually a divider that puts out 13 AMPLIFIER tones derived from a common clock frequency. If one of the 13 tones is on frequency then all of them have to be right. Using a 2.00024 MHz clock, you can produce the top keyboard oc- PROGRAM PROGRAM tave. LEADS LEADS Fig. 1 is a pin-out drawing Fig. 2. The block diagram of an effective music generator. The program leads could go to a switch and block diagram of the 50240. console or a piano-type keyboard, but the real intent is to interface them with a computer output port. You can change the clock fre- quency to suit your require- ments. With a 2.00024 MHz clock and a string of binary di- viders any note on a piano or or- gan keyboard can be produced. Running these notes into vari- ous synthesizer modules will allow you to come up with any sound desired. IC4.5.6.7 • 7400 ICS ,9,IO» 7404 Fig. 2 is a block diagram PIN 7" GNO PIN I4-+5V showing how a piano keyboard could be reproduced. This sim- ple but sophisticated system is described in "Try Computer Composition" by Kenny Wino- grad (July 1977 Kilobaud, p. TO COMPUTER 102). OUTPUT PORT

Hardware Fig. 3. Schematic of a simple computer-controlled music generator. The TTL ICs could be replaced For experimentation pur- with CMOS. poses I put together the simple circuit of Fig. 3. The 4001 and the 50240 go on the PC board tual selection is determined by that comes with the Top Octave the condition of the four data Leads Lead Value Experimenter's kit, but the rest leads (DO. D1, D2 and D3) from D C B A LOW H L the computer output port. of the ICs must be mounted in L L L L 0 A 1 0 some other fashion. In my case The 74154 (IC3) is a four-line- L L H 1 B 2 0 they went onto my IC bread- to-16-line decoder. If the binary L H L 2 C 4 0 board. code on lines A, B. C and D is L H H 3 D 8 0 Two of the gates of the 4001 zero (see Table 2), then all out- H L L 4 (IC1) are used as an oscillator put lines will be high except 0. If H L H 5 with the 10k pot for frequency the binary code is 1, then all H H L 6 H H H 7 adjustment. A frequency of lines except 1 will be high. Thus L L L 8 224,960 Hz fed from the oscilla- it is possible to control up to 16 H L L H 9 tor to the clock input of the top notes. H L H L 10 An inverter (ICs 8, 9 and 10) is octave generator (IC2) will re- H L H H 11 sult in the middle octave of a inverted in each output line H H L L 12 piano with A at 440 Hz. Chang- from the 74154 to satisfy the re- H H L H 13 ing the value of C1 will move the quirements of the 7400 gates. H H H L 14 range of the oscillator. A smaller Since the signal we want to H H H H 15 value will increase the fre- pass is positive-going, it will on- quency and vice versa. ly pass through the gate when Table 2. Truth table for the 74154 four-line-to-16-line decoder. With C1 equal to 360 pf (two the control lead is also high G1 and G2 must be held low at all times or all output leads will 180 pf disk capacitors in paral- (see Table 3). The output of the stay high no matter what the condition of A, B, C or D is. Only lel), the 13 semitones of the 7400 will be inverted, but this one output lead can be low at any one time. Leads A. B, C and D middle keyboard octave are does not present a problem. are coded in binary coded decimal (BCD). The leads have the present at the output leads of I used a combination of TTL value shown on the right. The values of all of the leads in an H the 50240. It is just a question and CMOS IC logic because (high) condition are added together to get the equivalent deci- of feeding the desired tone to that is what I had available. You mal value. For instance, if A and C are high then the decimal the amplifier. The various 7400 could replace the TTL ICs with value is 5. gates (ICs 4,5 and 6) are used to their CMOS equivalents. This switch one tone at a time to the would not only cut way down on common output point. The ac- the current requirements but

Lead Output NAND Gate PAIA 8700 Computer/Controller Kit $149.95 A B C Cassette Interface Option Kit 22.50 L L H 24.95 H Power Supply Kit L H control - B Top Octave Experimenter's Kit 14.95 H L H Write to PAIA Electronics, Inc., PO Box 14359, H H L Oklahoma City OK 73114, for their complete catalog of computer and music-synthesizer Table 3. If the control lead (B) is held low, the output will never products. change no matter what the signal lead (A) does. If the control lead B is held high, then the output will change as the signal Table 1. does, but it will always be inverted by the 7400 NAND gate. pressed. It does this by sending Address Label Op Codes Mnemonics Comments a 0 to the output port between 0020 LOOP 20 00 FF JSR KEYBOARD CALL KEYBOARD SUBROUTINE notes. 0023 BO FB BCC LOOP LOOP IS NOT NEW KEY A 0 from the keyboard will 0025 8D 20 A8 STA DISPLAY STORE KEY IN DISPLAY 0028 4C 20 00 JMP LOOP GET ANOTHER KEY shut off the music since none of the gates are connected to Program A. A 6502 assembly-language program that will cause the digital display of the 8700 to the 0 lead of the 74154. Keys 1 show the key number of each key as it is pressed. Changing 20 to 40 at location 0026 will allow the computer keyboard to control the music generator in Fig. 3. through D will play the 13 notes of our scale (see Table 4). This is exactly like a piano key- board, but as I've mentioned it is better and more fun to teach the computer to play for us. Address Label Op Codes Mnemonics Comments This is accomplished by stor- 0020 LOOP 20 00 FF JSR KEYBOARD CALL KEYBOARD SUBROUTINE ing notes in memory and then 0023 B0 02 BCC OUT GOTO OUT IF NEW KEY feeding them to the music 0025 A9 00 LDA NOTONE CLEAR A REGISTER 0027 OUT 8D 40 A8 STA MUSIC OUTPUT TO MUSIC board along with the proper 002A 4C 20 00 JMP LOOP CHECK KEYBOARD AGAIN timing for each note. Program B. A slight modification of Program A disables the tone when a key is not being pressed Using the techniques pre- by putting out 0 (no tone) when the keyboard subroutine returns with the carry set (no new key). sented in Winograd's article, you can put together an inex- pensive but sophisticated mu- sic-generating system. The would also eliminate the need more of the data leads. In fact, Software 8080 software in that article for the + 5 volt supply since the for a simple piano you could re- The 8700 Piebug monitor (in would have to be rewritten in whole thing could run on +12 move the 74154 and connect its ROM) has a subroutine at FF00 6502 assembly language, but it volts. output leads directly to a group that scans the keyboard, and is a simple program and The 7400s could be replaced of switches (Fig. 4), eliminating when it finds a key depressed, shouldn't present any prob- by 74C00s or 4011s, the 7404s the computer completely. How- it returns with the number of lems. by 74C04S or 4069s, and the ever, if this is possible why do the key in the A register. It also 74154 by 74C154 or 4515. You we even need the computer? clears the carry flag if this is a Conclusion could also use 4514 in place of Yes, you can play this like a new key since the last scan. These same methods could the 74154, in which case the in- piano with the switches in Fig. Program A is a simple 6502 also be used to control other verters (ICs 8, 9 and 10) would 4, but if you are not a musician, assembly-language program devices. In fact, anything that not be needed since the output the result may be unpleasant to that reads the computer key- can be turned on or off or ad- leads of the 4514 are already in- listen to. By storing the notes of board and sends what it sees to justed electrically is a candi- verted. a composition in memory, you the digital display. It does this date for computer control, The 74C00 and 4000 series can let the computer keep track by calling the keyboard subrou- which is what the PAIA 8700 ICs are not pin-for-pin compat- of the timing and play them for tine, checking to see if it is a was designed for. ible with their 7400 counter- you. The tempo can easily be new key, and if it is, it stores the Computer music is an enjoy- parts and are generally more changed, and you can save the key number at A820 hex, which able subject for software and expensive than TTL. Motorola music code on tape in order to is the address of the digital dis- hardware experimentation. It identifies their CMOS products play it again another time. play. As you press each key, its also satisfies the urge to do with the prefix MC1. Thus the The Winograd article men- number appears on the display. something creative with your 4011 would be MC14011. Other tioned previously does a good The parallel output port ad- personal computer. When manufacturers prefix the de- job of covering both hardware dress is A840 hex, and if we friends ask if your computer vice number with CD—thus and software, so I won't try to change the 20 hex to 40 hex at can do anything besides play CD4011. go into too much detail here. location 0026 in Program A, games, it is great fun to pop in a Without connecting Fig. 3 to However, let's see how the 8700 then the key number will be music cassette and let it play a the computer, you can test the can be used to control the top sent to the output port instead tune for them.H circuit by grounding one or octave generator. of to the digital display. With our little music board connect- ed to the lowest four bits of the Key Note ifi output port, we can control the Key Note notes from the computer key- 0 NONE 7 F# board. 1 C 8 G One disadvantage of Pro- 2 C # 9 G # gram A is that a note will con- 3 D A A tinue to sound until a new key is 4 D# B A# 5 E C B pressed because the 7800 out- 6 F D C put port is a latched port that will hold its present value until Table 4. List of the notes it receives a new value. Pro- that correspond with the first gram B takes care of that by 14 keys on the 8700 key- Fig. 4. A 13-note keyboard. More than one note can be played at a shutting off the tone, except board. time in this configuration. while a key is actually being TBS DEALERS HAVE FULL SYSTEMS SUPPORT. You've just purchased But even more important, a Centronics printer. SYSTEMS EXTEN- Where do you get the SYSTEMS SIONS provides a source printer supplies needed to of supply for a series of pro- keep it functional? You've EXTENSIONS ducts applicable to all com- just purchased a disk drive. For TRS-80 and Other Microcomputer Syst puters. Through this Where do you find a publication TBS and its source of quality diskettes affiliate dealers offer over and storage devices to keep 300 items including soft- them organized? You have ware, diskettes, cassettes, invested over % 1,000 in printer supplies, storage your system. Where will units and furniture. In you find all the necessary other words, TBS and its items to keep it opera- dealers stock everything to tional? The answer: TBS make the microcomputer and its affiliate DEALERS. a full scale business system. The LIBRARY 100 At the heart of your Software Pack was pub- computer system is the lished in November of software. We now offer the 1978. Since that time, it following programs for the has been widely accepted TRS-80: TBS Business throughout the United Mail System for dual disk States and 31 countries as and printer; Check Regis- a major advancement in ter Accounting System microcomputer software. Computers of the Past Reviev. of the Electric Pencil for dual disk and printer; Computers of the Present The Diskette Revolution Now, we at TBS have Computers of the Future The TRS-80 and the Business Community Basic Toolkit, a pro- Methods to Program Your System Computer Aided Instruction expanded our endeavor to Software Background Report The Microcomputer and the Wall Socket grammers aid: System Preparation for Programming Level II Index better meet the product Standards for Professional Programming Random Ramblings Doctor, a computer diag- Security of Business Data and Programming needs of our customers. Purchase. Care and Maintenance of the Business Computer nostic program; Check- A camera is useless book II, cassette based without film; a typewriter is useless without paper; personal finance; Information System, an a computer system is useless without the necessary "in-mem" data base manager; Analysis Pad; a support to make it completely operational. TBS is columnar calculator; Terminal Control, for leading the way in systems support, and we are RS-232 tele-communications; Exerciser, for proud to announce a new concept for the micro- establishing physical fitness goals and regimens: computer industry - FULL SYSTEMS plus, Electric Pencil; Fortran by Microsoft; SUPPORT. Mainframe and minicomputer NEW DOS + ; and of course, the Library 100. industries have been following this concept for Details in full are included in SYSTEMS years. However, until now it has not been EXTENSIONS. available for microcomputer systems. TBS Full We at TBS believe in the microcomputer revolu- Systems Support is aimed at helping you, the tion. Our purpose is to serve you, the microcom- computer owner, acquire the necessary support puter owner and user, by supplying the necessary items quickly and inexpensively through a net- items you need. To this end we have published work of affiliate dealers nationwide. SYSTEMS EXTENSIONS, and it is available We also realize that there is limited material nationwide through TBS dealers and Radio Shack available on computers in general. To fill these Associate stores for only $3.00. For further infor- needs we have produced SYSTEMS EXTEN- mation please call us at the number below. SIONS. This is a unique publication which pro- vides a theoretical computer background for the The Bottom Shelf. Inc. ^B33 novice computer user and some specific points of P.O. Box 49104 programming interest for TRS-80 users. Seven- Atlanta. Georgia 30359 teen articles are included in 63 pages of solid text. Phone: 404-939-6031

Microcomputing, October 1979 43 K* Reader Service—see page 227 An Inexpensive TRS-80 Printer Interface

Why spend $300? Try Small System Hardware's $49.95 alternative.

Sherman P. Wantz Hardware auxiliary jack. regularly by suppliers whose 424 NW Lakeview Drive The assembled and tested I soon discovered that the ads appear in this magazine. Sebring FL 33870 TRS-232 interface unit arrived at connect/disconnect procedure Only two signal connections my home about three weeks was too easy to forget. There- had to be made to the BD-25 after I had mailed my check for fore, I followed the manufac- plug to tie the interface unit to $51.95 ($49.95 for the unit plus turer's advice and built a patch my teleprinter. Pin 9 provided f you own a "bare-bones" $2 to cover shipping and han- cord from audio cable, which I - 12 volts dc, and pin 10 provid- I dling) to Small System Hard- terminated at both ends with ed + 12 volts dc. These connec- TRS-80 microcomputer sys- ware, PO Box 366, Newbury Park miniature plugs (Radio Shack tions supplied the 20 mA loop tem, you will eventually want to CA 91320. catalog number 274-286). I in- current needed to operate the buy Radio Shack's $300 expan- The TRS-232 consists of three stalled the patch cord per- ASR-33 Teletype. Consult your sion interface to provide you parts: a 1 x 2 x 3 inch box con- manently between the TRS-232 teleprinter manual for appro- with additional memory space, a taining a 741 op amp IC, a tran- and the recorder's auxiliary jack priate connection points to be floppy disk capability, an RS-232 sistor, five diodes, resistors and (see Fig. 1) and can now print or made on your machine's termi- serial port and a parallel port to capacitors —all mounted on a record programs without both- nal board. feed a fast line printer. But sup- small circuit board; a cassette ering to connect or disconnect The pins of the BD-25 female pose you have a printer and tape that contains a program signal cords. socket mounted on the TRS-232 would like to connect it to your written in Level II BASIC; and a Power for the interface com- are not numbered. Fortunately, TRS-80 but can't see your way ten-page booklet that includes ponents is obtained through a however, those pins on the clear at the moment to spend instructions, a schematic dia- line-cord connection that plugs matching male connector are $300? gram of the unit, a program into any 115 volt wall outlet. The numbered; this helped me to That oversimplified scenario listing in BASIC and an assem- TRS-232 contains no off-on make the correct coupling be- described my condition before I bly-language source listing. switch. It is on when it is tween the interface unit and my read the ad in Microcomputing As the instruction booklet ex- plugged into the wall outlet. teleprinter. about Small System Hardware's plains, the TRS-232 obtains its The line-cord plug houses a If your printer does not re- TRS-232 printer interface unit. I signal via the gray cord that nor- small transformer. Current drain quire 20 mA of driving current— learned that for a modest invest- mally connects the TRS-80 com- through the transformer is so as does my machine—your out- ment I could give my TRS-80 a puter to the auxiliary jack of the small that the housing barely put signal connections to the in- hard-copy capability, thereby tape recorder. To use the printer, feels warm to the touch. terface unit will differ from satisfying at least a part of the you must remove the miniature The output signal produced those I have just described. advantage I had hoped to plug covered by a gray sleeve by the interface unit is fed to the achieve by buying Radio Small System Hardware claims from the recorder's auxiliary printer via a 25-pin BD-25 female Shack's expansion interface. to have used their interface unit jack and plug it into either of the connector that is mounted In response to the inquiry I to drive RS-232 compatible print- two jacks that are mounted at along one edge of the TRS-232's mailed, using Microcomputing's ers of all types. RS-232 is the each end of the interface unit's case. Reader Service card, Small Sys- specification number that was case. The jacks are connected in tem Hardware sent me a bro- Since the manufacturer as- given by the Electronic In- parallel so it makes no differ- chure that described its TRS-232 sumes that your printer is dustries Association to stan- ence which one you use. in detail. The brochure con- equipped with a BD-25 male con- dardize voltage and impedance vinced me that the TRS-232 was If you should want to use the nector, he provides none. I levels for transmission of digital what I needed to connect my tape recorder to dump (CSAVE) bought the appropriate male data. TRS-80 microcomputer to my a program in memory to tape, BD-25 connector for $2 at the Please note that the TRS-232 ASR-33 teleprinter so that I you must remove the miniature Orlando hamfest flea market. interface unit provides a "re- could use my Level II BASIC'S gray plug from the TRS-232 jack New connectors, some com- ceive only" one-way printer LLIST and LPRINT commands. and reinsert it in the recorder's plete with cable, are advertised capability, so don't expect it to permit you to use your printer's "pokes" your answers—using the design really is. The diagram plete listing in assembly lan- keyboard to send characters to machine language—into re- promotes the idea—whether guage and machine code of the your computer. served memory. realistic or foolhardy—that relocatable driver for the To test the operation of the anyone who can read a sche- TRS-232 is provided. The code printer interface hookup, turn matic should be able to trouble- can be placed anywhere in mem- Software your printer's motor on, type shoot and repair the interface ory since no calls and only rela- Once you have your interface LLIST on your TRS-80 keyboard unit. There should be no reason tive jumps are used. hardware installed between and press the Enter key. You for anyone to return the Level II Baud rate selection (110 to your TRS-80 and your printer, should see the TRS-232 BASIC BASIC initialization program 9600), line feed and nulls follow- you will be ready to load program that you just loaded in- cassette to Small System Hard- ing carriage return options are (transfer from cassette tape to to memory being transferred ware because he can't load it in- provided, just as they are in the computer memory) the Level II from computer memory to your to his computer. Level II BASIC program. There- BASIC program that is supplied printer. Since the instruction manual fore, with the TRS-232 interface, with the TRS-232. This program Since the TRS-232 BASIC pro- contains a listing of the entire you can obtain a print capability converts parallel data into serial with your machine-language form to operate your printer. programs as well as with those When you apply power to your that are written in Level II Level II BASIC microcomputer, BASIC. the words "MEMORY SIZE?" ap- Conclusion pear on your video monitor's screen. When these words ap- If you have a printer that you pear, you will be expected to re- want to use with your TRS-80 spond appropriately to reserve system, you could hardly ask for memory space for the TRS-232 a more reliable unit to tie com- print function program. puter and printer together than If your system contains 4K the TRS-232. Small System bytes of memory, you should Hardware claims to have used type "20360" to reserve space the TRS-232 to interface with for the 110 bytes required by the Diablo, Texas Instruments, Cen- program; if your machine con- tronics, Teletype and Selectric tains 16K bytes of memory, you printers. should type "32650." Press the Since the TRS-232 is not a kit Enter key. Now you are ready to —it comes fully assembled and Fig. 1. TRS-80 connections that place the interlace in series between tested—you will need no spe- CLOAD the 52-line TRS-232 the TRS-80 and the two output devices-printer and recorder. Level II BASIC program from cial skill, beyond the ability to cassette tape into computer follow written instructions, to in- memory. gram has served its purpose program (52 lines long—includ- stall it in series with yourTRS-80 My program loaded without after it has "poked" your ing 16 REMark lines that need microcomputer's output cable problem at a volume setting of printer's specifications into not be used), it would be far (the gray cord that terminates in "4" on my CTR-33 recorder. For reserved memory space, it is no simpler to type the program into a miniature plug enclosed in a those who use the CTR-41 re- longer needed. Type NEW to memory using the computer's gray plastic sleeve). corder, the manufacturer recom- erase it before you load the keyboard and then CSAVE it us- When you inspect the mends a volume setting of Level II BASIC program you in- ing your own computer, recorder TRS-232 hardware housed in the about "6." After the program tend using with your printer. and cassette tape. Because of 1x2x3 inch box, you may feel has loaded, type "RUN" and slight record-head-alignment that the $49.95 price you paid for Documentation press the Enter key. differences that exist among the unit is a bit steep. The price In succession, the program In addition to containing in- tape recorders, it is almost was $39.95 in December 1978 will ask four questions. Your structions for connecting the always easier to CLOAD tapes and jumped $10 at the beginning answers to three of the ques- interface unit to your printer and made on your own recorder than of 1979. However, when you re- tions will configure the program for using it, the ten-page booklet it is to load from tapes recorded member that your purchase to operate with your particular that comes with the TRS-232 on other machines. price also paid for a software printer. Your response to the contains several noteworthy ex- Having the Level II BASIC package that will allow the questions will: reconfirm the tras. If you are curious about listing in your instruction same hardware unit to connect amount of memory space you how the TRS-232 works, a sec- manual gives you peace of your TRS-80 to the next serial reserved for the program when tion of the instruction manual, mind, too. Even if you do in- printer you acquire, the price you turned your system "on"; entitled "Theory of Operation," advertently store your ini- doesn't seem too far out of line. specify the baud rate at which will explain it to you in simple tialization program cassette I am quite pleased with the your printer operates; declare terms. In this section of the next to your TRS-80 system's hardware, software and instruc- whether or not a line-feed signal manual, the manufacturer power supply and partially erase tion manual that comprise my must be sent to the printer fol- points out that the TRS-232 is it, you can always regain the use TRS-232 interface. For my $50 lowing each carriage return; and not certified as an interface that of your interface unit by typing interface investment, I obtained specify the number of nulls your will meet all EIA Standard and rerecording the program. the use of a teleprinter that cost printer requires (if any) after RS-232 requirements and speci- The instruction manual con- at least ten times that much. each carriage return. Once you fications. tains a special bonus for those Particularly for a computer hob- have answered these four ques- The schematic included with who do their programming in byist, that's not a bad invest- tions, the BASIC program the manual shows how simple Z-80 machine language. A com- ment ratio. • Jerry Sorrels 6266 Banner Ct. Riverside CA

Eyes for the AC-30

A simple modification lets you add monitoring features to your AC-30 cassette interface.

or over a year I had been I used were an SPST toggle and replaced after cutting the nector labeled LOCAL/REMOTE Fusing a Bit Boffer (see switch and a 1k resistor (see trace. What luck! on the placement diagram. "Build a Bit Boffer," Byte, Fig. 1). Now, on the bottom of the I mounted the switch at the March 1976) to load programs board connect a wire from IC14, right rear of the cabinet, out of into my SWTP 6800 computer. It How It's Done pin 11 to an unused pin on the sight but still accessible. I have worked just fine but lacked the To add this modification to rear center board connector; since considered moving the ability to change from play to your AC-30, remove the circuit next on the bottom, solder a 1k power switch to the back and record and to start and stop the board from the case. Next, on resistor, R1, from IC14, pin 11 to the monitor switch to the front recorder under software con- top of the board, cut the trace IC14, pin 16, which is +5 volts. because sometimes I forget to trol. between pins 10 and 11 of IC14 Connect one side of the switch put it in the normal position and At first this was no problem —it will be under the IC or its to the male pin that matches wonder why the computer is . .. I had enough on my hands socket. I discovered that on the the vacant board connector you not speaking to me. just getting the programs type of sockets I used (I always used. The other side of the When you want to monitor a loaded and working. But as use sockets) the plastic hous- switch connects to the pin that tape you are loading, place the time went on, I became smarter ing could be pried off the pins matches the rear center con- switch in its open position. This and lazier. will change data selector IC14c Enter the SWTP AC-30 audio from the computer to the cas- cassette interface. After using sette demodulator output. This it for a short time, I missed one causes the data to be sent to LOCAL/REMOTE of the features of my old Bit V the computer and to the termi- Boffer: the ability to display the • 5 nal. When the switch is in its normal position (closed), the data on my SWTP CT-1024 ter- R4I minal at the same time it was be- LOCAL/REMOTE AC-30 operates normally. This ing loaded into the computer. modification is especially use- This feature lets you verify if ful when you're loading some- the tape is being read properly. one's tape other than your own Also, you know when the end is for the first time without having nearing. to check its readability in the LOCAL mode first. But its best feature is that it |n ICI4c gives you something to look at If the computer receives bad while waiting for the program data during a normal load, it to load. 300 baud is just a little will send question marks to the slow! terminal. Remember: With the After looking over the SWTP switch in the monitor position, the terminal is looking at the 19 x 25 inch schematic (nice 1 and big), I came up with a simple AC-30, not the computer; but if there is bad data, the TVT way to add this monitoring fea- Fig. 1. Section of AC-30 cassette-tape-switching schematic ture to the AC-30. The only parts showing modification. should show it anyway • The InterTube II Video Display Terminal is truly representative of the latest state-of-the-art advances in microprocessor technology. Its basic teletypewriter compatability combined with its numerous "smart" terminal features satisfy the universal requirement for a low-cost, high performance video terminal. You get everything you need. An upper and lower case character set displayed on a sharp 8 X 10 dot matrix. A full 24 line by 80 character screen. A status line displayed in reverse video. A complete ASCII keyboard with an 18-key numeric pad. You get full cursor addressing, automatic repeat of all keys and individual backspace and shiftlock keys. Plus, a graphics mode for easy design and display of all types of forms. And an RS-232 serial printer port. And you get everything your operators need to make their jobs a pleasure. A hooded display that cuts glare and gives INTERTEC'S extra privacy. A wide bandwidth monitor for sharp images everywhere on the screen. Below-the-line character descenders to make reading easier. A programmable white-on-black or black-on-white display and a self-test mode for easy maintainability. INTE3TU3E11 You get high powered text editing with VIDEO DISPLAY TERMINAL such features as character and line insert/delete, full and/or partial block transmit, programmable end-of-line terminators, and protected fields. All ATTENTION OEM's and DEALERS: standard! And all for a retail price you Your customers request InterTube won't believe . . . only S995. Incredible! terminals for one simple reason. They outperform the competition so well that it's foolish to consider any other terminal. Add to that InterTube's rugged design which insures you of the reliability that brings customers back. And modular design engineering that makes service a snap! But best of all, the InterTube is readily available. Just a quick call and you'll have units in stock. Immediately! And our scheduled delivery program will help you keep them in stock. 3ood margins, good service, good delivery. Simple? You bet it is! InterTube II dealerships and OEM agreements are now available in many areas. Contact us today and start selling from stock tomorrow!

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S Reader Service—see page 227 Microcomputing, October 1979 47 Expanded TRS-80 Disk Operations

Putting "system" programs on disk is the topic in this, the first of a two-part series.

Allan J. Domuret or T-BUG from disk because into upper, unused memory with stands what is happening in 7825 Willowcrest Way these programs reside in the RSM2. Then a short block-move this simple routine, can apply Fair Oaks CA 95628 same memory area as does subroutine (15 bytes) is perma- the same technique to other DOS. nently attached to the system system programs such as To quote from the new Radio program to automatically move T-BUG, Radio Shack's Editor/ Shack "Disk Operating Sys- the entire system program to Assembler, and so on. his article has two objec- tem" manual for TRSDOS Ver- its proper memory location for The recent release of a disk Ttives. One is to explain how sion 2.0: "Most Radio Shack execution. Finally, the Tape- version of the Electric Pencil to put low-RAM machine-lan- system tapes designed for use disk routine is used to put the for the TRS-80 will not obviate guage programs on disk, a pro- with Level II TRS-80s will not program and its block-move the relevance of the procedures cedure that is not routinely sup- work under Disk BASIC be- subroutine onto disk. described in this article. The ported by the Radio Shack disk cause of differences in RAM us- Subsequently, when the pro- technique is still applicable to operating system (DOS). Sec- age under Disk BASIC and Lev- gram is loaded from disk, it is any system program, and, no ond, the techniques described el II" (pp. 5-6). On the same loaded into upper memory with doubt, there are those who may herein will serve as a good in- page of the DOS manual is a an execution address that initi- not be able to afford the new troduction to machine-language comment that states, "Do not ates the block move. The block disk version of the Pencil. programming for beginners. attempt to use Tapedisk to load move takes over and transfers Also, the ability to load the The techniques make use of tape files that load below hexa- the program to its proper mem- Editor/Assembler from disk the Small System Software decimal address 54F4 (decimal ory location. When the block eliminates much of the RSM2 or RSM2D machine-lan- 21748). Tapedisk uses this move is completed, a jump to drudgery from machine-lan- guage utility program. RSM2 area." (Tapedisk is a utility pro- the program's execution ad- guage programming. It only has many features, and only a gram that allows the user to dress completes the operation. takes a moment for your ma- few are described herein. If the place system tapes on disk, The program will then run nor- chine-language program to user does not have RSM2 in his provided that memory required mally. crash, but it takes many frus- software library, this article by the system program does Moving the system program trating minutes to reload the can still be educational. It is not overlap that required by to lower RAM in this way over- EDTASM and the source mod- suggested, however, that RSM2 Tapedisk or DOS.) In other writes DOS because DOS re- ule for making repairs. or RSM2D is an invaluable utili- words, it is not possible (nor- sides in the same memory loca- Part 2 of this article will ex- ty for TRS-80 owners. RSM2D is mally) to put a machine-lan- tion as the moved system pro- plain how to put Peter Jenning's the disk version of RSM2. guage program on disk if the gram. But this is inconsequen- Microchess 1.5 on disk and program conflicts with DOS in tial because only the system also how to make backup TRS-80 Disk Operations low RAM. program will be run—DOS will copies on cassette tape. As The comparatively low price This means that the inexperi- not be needed while the system most TRS-80 users have be- of the TRS-80 microcomputer, enced TRS-80 user cannot easi- program is running. For ex- come aware, Microchess 1.5 no doubt, contributes consider- ly put system programs such as ample, DOS and the Electric cannot be duplicated on cas- ably to its popularity, but, as an T-BUG, Electric Pencil or Editor/ Pencil normally reside in the sette tape by ordinary means. old philosopher once said, Assembler on disk with avail- same memory area, but only You paid good money, however, "You get what you pay for." It able routines such as Tapedisk. one program will be used at a to purchase Microchess, and seems that whenever a TRS-80 With a little skill and cunning, time. Wiping out DOS by over- we all know the importance of user updates or adds to his sys- however, it is possible to load writing it with the Electric Pen- having backups of valuable pro- tem, he encounters some kind these low-RAM system pro- cil does nothing to interfere grams. It is also an educational of new frustration. What I refer grams from disk, thereby elim- with normal Pencil operations. experience to learn how to du- to is a deficiency in Radio inating the need for much The "Save-to-Disk" technique plicate Microchess. I can only Shack's DOS, which precludes slower tape loading. described in this article will use encourage TRS-80 users not to loading system programs such The technique involves load- the Electric Pencil as an exam- abuse this knowledge by mak- as the Electric Pencil, EDTASM ing the desired system program ple, but the reader, if he under- ing free copies for friends. (Sorry, Mr. Jennings, but knowl- Disk BASIC occupies memory contrast to the R 0 command). represents the hex op codes, edge must be shared.) space that, when added to mem- The R command will load in the which tell the computer what to ory space used by RSM2, leaves program and will display the ex- do; and the next column group RSM2 and RSM2D an insufficient amount of mem- ecution address at the end of (JP 52DA) represents the sym- System Monitor ory for our operations on the the program. The R command is bolic code to JUMP to memory location 52DA hex. As I stated, RSM2 and RSM2D Pencil program. In spite of limi- used for reading in non-system will be used as a tool to accom- tations imposed by 16K sys- programs, but will read in sys- To find the end address, just plish our purpose. The only dif- tems, the techniques described tem programs with all coding let the memory scroll continue until a long string of zeros is ference between RSM2 and herein will still work for loading characters preserved in mem- again encountered. By now, the RSM2D is that the latter has Pencil from disk. ory. The execution address for a importance of zeroing all un- some disk-related features. After RSM2 is operational, it system program will follow the used memory as we did at the These disk features are not re- would be a good idea to clean up termination code "78" at the start should be obvious. The last quired for the techniques em- all memory locations to avoid end of the tape. instruction in the Pencil pro- ployed in this article, so they confusion later when working After loading Pencil with the gram should read: will not be referred to again. on the Pencil. Before loading RSM2 R 0 (not R) command, Subsequent references to Pencil into memory, zero out all Pencil should be in its normal 5365:29 ADD HI_HL RSM2 apply as well to RSM2D. memory locations from 4200 hex memory location, but RSM2 will The end address is 5365, and RSM2 has several tape-relat- to a place in memory just short still be in command of the ma- the 29, rather than representing ed features that enable the user of running into RSM2. For a 16K chine. To determine Pencil's a machine-language op code, is to read and write system tapes TRS-80, RSM2 resides at 6C00 to start and end addresses, use actually an ASCII character for and to read virtually any ma- 7EFF hex (see "Supplementary either the RSM2 ASCII or sym- ")". An "ADD HL,HL" sym- chine-language tape into mem- Information" provided with bolic dump commands. The bolic instruction is displayed ory (including Microchess). RSM2 documentation). The ASCII dump is faster for locat- because the RSM2 disassem- These tape features are neces- command for a 16K system ing the Pencil in memory, but bler interprets the 29 op code as sary for structuring system pro- would be: "Z 4200 6BFF." For the symbolic dump is more pre- an "ADD HL,HL" instruction. grams that will eventually be the other RSM2 versions, zero- cise in determining exact start RSM2 really has no way of tell- saved on disk. ing memory from 4200 to, say, and end addresses. ing if the 29 is an ASCII char- Before proceeding, I should 8000 will be adequate for our To get an ASCII dump, answer acter or an op code without ac- mention that either the 32K or purposes. RSM2's "COMMAND?" prompt tually running the Pencil pro- 48K version of RSM2 is prefer- Now when we load in the Pen- with: "A 4300." This will give a gram. able to working with the 16K cil program, there will be noth- scrolling ASCII display of every- This is a common fault for version. If you must work with ing else in lower RAM to confuse thing in memory starting from most disassemblers, and the the 16K version because of lim- us as to which instructions memory location 4300 hex. Stop user should always be aware of ited memory availability, it will belong to Pencil and what might the scroll as desired with the this problem so that ASCII char- be necessary for you to deter- otherwise be hanging around as space bar. Since we initially acters are not inadvertently in- mine your own memory-address leftovers from DOS or some zeroed all memory locations be- terpreted as op codes. ASCII requirements as described in other program that is no longer fore starting, and since RSM2 characters can be found easily this article. needed. The only memory loca- resides in higher memory, we with RSM2 by dumping memory Using the 32K or 48K version tions that will not be zeroed will can be certain that the first with the ASCII dump command of RSM2 should present no be the Pencil program, which we nonzero data encountered dur- and finding the English lan- problems because most TRS-80 will load. ing the ASCII or symbolic dump guage text in the program. For users quickly learn that a 16K Prepare the cassette recorder belongs to the Pencil that we Pencil, this English language system with DOS is really not and read in Pencil with the loaded in with RSM2. text is found in upper memory. enough. Consequently, they RSM2 "R 0" command. When Since the ASCII dump makes At this point, I must add that usually move up to 32K or 48K the Pencil is loaded, RSM2 will it difficult to precisely read pro- Pencil is recorded on the cas- of memory rather quickly. Those display the file name—PENCIL gram addresses, the exact start sette tape with ten trailing zeros of you who will be using the 32K —and it will also display the ex- address for the Pencil can be after the last code, 29.1 learned or 48K RSM2 can use the pro- ecution address. For Pencil, the determined with the RSM2 sym- this by loading Pencil into mem- gram address numbers exactly execution address will be 4350 bolic dump. Start the symbolic ory with the RSM2 R command, as provided in the following hex. Write down the execution dump at, say, 4300 hex by typing in contrast to the R 0 command. paragraphs. address for later use. in: "S 4300." Notice that adja- The R command will read vir- The first step in creating our By the way, in case you won- cent to the displayed memory tually any tape, whereas the R 0 disk file is to determine the dered, the Pencil execution ad- locations between 4300 and command is for reading only start, end and execution ad- dress is physically located at 434F are zeros (00) and NOPs. system tapes. dresses of the selected system the end of the cassette tape pro- This is because we zeroed all If you care to experiment, program. As was stated above, gram, and this holds true for memory before loading in the read in Pencil using the RSM2 R we will use the Electric Pencil most system programs. This is Pencil. When the dump reaches command, and at the end of the for our example. To determine how the TRS-80 knows where to 4350 hex, the start address for program you will find the ten these addresses, load either the go to execute a system program the Pencil, you will see: trailing zeros, followed by a few 32K or 48K version of RSM2 as when you enter the slash (I) after 4350: C3 DA 52 JP 52DA other characters, including the you would any typical system normal tape loading, and this is followed by the rest of the pro- '78' termination code and, at the program. how RSM2 is able to tell you gram in Zilog mnemonics. end, the execution address as I If you are still limited to a 16K what the execution address is. The first column (4350) is the mentioned above. Little peculi- TRS-80, it will be necessary to If you want to check this out, hex memory location of the first arities like these must be found work in BASIC II rather than in read the Pencil into memory instruction in the program; the when manipulating programs at Disk BASIC. The reason is that with the RSM2 "R" command (in second column group (C3 DA 52) the machine-language level. At