Computersalectronics AUGUST 1983 Formerly Popular Electronics $1.50

Computersalectronics AUGUST 1983 formerly Popular Electronics $1.50

Printers for Small Computers Radio Shack's New Micro Color Computer Testing the Microbuffer II Printer Interface Compact DiscDigital Audio Systems

Also In This Issue: 08 o heT !Latest Flat -Panel Displays 1111 First 4024 1427 Look at Magnavox's CD Record Player

www.americanradiohistory.comAmericanRadioHistory.Com You can wait for industry siandards to mandate improved performance. Or you can have it now on Maxell. The Gold Standard. The refinements of The Gold Standard, from clear and accurate. And lubricants reduce fric- oxide particles to lubricant to jacket, are uniquely tion between head and disk for a longer media Maxell. And therefore, so are the benefits. and head life. To house it, we then Our unique, uniform crystals assure dense a constructed a new jacket heat - oxide packing. So you begin with an origi- resistant to 140° F to withstand drive nal signal of extraordinary fidelity. A signal heat without warp or wear. And we safeguard in ways that leave industry created the floppy disk that standards in our wake. leads the industry in error -free performance and durability. An advanced binder bonds oxides to the base material preventing time All industry standards exist to and money- wasting dropouts. assure reliable performance. Calendering then smooths the sur- The Gold Standard expresses face for a read /write signal that stays a higher aim: perfection. mexeII. IT'S WORTH IT Computer Products Division, Maxell Corporation of America, 60 Oxford Drive, Moonachie, N.J. 07074 201 -440 -8020 Circle No. 30 on Free Information Card

www.americanradiohistory.comAmericanRadioHistory.Com the KLH Solo Price Slashed List Price $199- Suggested Retail $169 January 1983 Dealer Cost $106 NOW $68 It's been killing us. We bought these KLH stereos in April, but we agreed not to sell them till June. You see, the local KLH dealers still had lots of them in stock. Most were selling the Solo for $169 (the very cheapest discount ad we've seen was $129). And, the dealers had to have time to sell out their stock before our ads hit. So, we've been raring to go since April, while we've sat on DAK's best buy ever. The KLH Solo was built to sell for $169 to $199 and to wholesale for $106. It represents the very top end, state of the art in electronics. It's the audiophile's choice in personal stereos. But, unfortunately because of our last recession there just haven't been as many rich audiophiles around. So KLH ended up with 14,000 of these remarkable stereos. DAK bought them all for cold hard cash. So if you're into absolutely the best sound in cassettes, complete with auto- reverse, dual flywheel anti -rolling design, and if you'd like incomparable FM reception from the included FM stereo tuner pack, the KLH Solo is for you. And don't worry. All of our KLH Solos are brand new factory sealed direct from the manufacturer. The KLH Solo will make the sound of your cassettes and FM stereo explode with life. It gives you auto- reverse. The sound is simply breathtaking, and so is the incredible $68 price. It's vibrant. And, the sound seems to other high end personal stereo. super stability with other top of the line be alive. The KLH Solo brings thun- Then, when you've left them in the stereos, then you'll really appreciate the deringly powerful realism to personal dust, do the same test against the tuner achievement that the Solo represents. stereo. And frankly for its $169 price in your own stereo system. You might The Solo is only 1/4" wider than a tag, it had better sound great. just be in for a very big surprise. cassette box (4Yz" X 31/2" X 1 Y2 "). It oper- In a market flooded with cheap Hong The FM tuner pack simply fits into the ates on only two AA batteries (not in- Kong imports, the KLH stands out as the Solo like a cassette. And retracting pins cluded). And,it's backed by a limited 90 Audiophile's choice. And even though direct -connect it with the Solo. day warranty by KLH. DAK is able to offer the KLH Solo to you The FM signal goes directly into the TRY THE KLH SOLO for just $68 (a $101 saving), let's look at amplifier, not through the head and it RISK FREE what has made it worth $169. works off the deck's power. It uses the Take the Solo on walks, as you corn- u headphone cable as a super antenna. mute to work, while you work or relax. ñv -ñ There's no tape /tuner switch because Don't put it away when you get home DEALER PRICE SCHEDULE the KLH Solo is intelligent enough to or to the office. With our optional cable, EFFECTIVE JANUARY I. 19E3 know when its tuner pack is inserted. you can plug into your home or office But, all of the above wouldn't mean stereo system for continuous nonstop 5 200 no 99 95 1.19995. 110E. 00 anything if it weren't for the incredibly p ay of your favorite cassettes. Here's a sensitive FM tuner circuit. It utilizes a stereo you can use all the time. AUTO REVERSE sophisticated 20 pin integrated circuit If you aren't 100% satisfied, simply The anti -rolling transport of this deck to produce dramatically alive FM sound. return it to DAK in its original box within is incredibly stable. It uses twin match- ALL THE BELLS AND WHISTLES 30 days for a courteous refund. ed stabilization flywheels in conjunction The Solo comes with a heavy duty pro- To order your KLH Solo with FM Tuner with a specially designed motor to give tective leatherette case, a matching case Pack risk free with your credit card, call you rock stable bidirectional play. that holds 3 cassettes, a shoulder strap toll free or send your check not for the With auto reverse, your cassette need and a removable wrist strap. the $169 suggested retail price or even never stop. It just plays back and forth You can attach the case to your belt or the $103 Jan 1 983 dealer cost. Send just over and over again. It makes listening look at this, there's a 'screw -on' living $68 plus $3 for postage and handling. while you're on the run a real pleasure. hinge belt or waist band clip too. Order No. 9683. CA res add 6% tax. And, at home or in the office, with our So many features. There's a metal/ And there's more. We have a bonus optional home stereo cable you can plug normal equalization switch. The Solo cable that you plug into an earphone this auto-reversing deck into any 'aux' reverses automatically plus even its re- jack on the Solo and into any stereo 'aux' jacks on your stereo system for an eve- verse button is power assisted. inputs on your home stereo. Just add $4 ning or a day of uninterrupted music. There are 2 LED arrows to show tape ($1 P&H) Order No. 9200. Wait till you hear the quality of the direction. And while we're on the sub- Never buy batteries bonus. We'll in- sound from this audiophile cassette deck. ject of 2s, there are 2 headphone jacks clude a charger and 4 nicad batteries And, while this deck is plugged into your and 2 volume controls. (that's two in and two charging) so you'll stereo system, you can copy cassettes Along with the 2 stability flywheels, always have music. It's a $24.65 retail by playing them on the Solo and copying there are 2 capstans. There's only one value, but it's yours for just$12.99 ($1.50 them on your home cassette deck. mute button. But, it cuts off the sound on PEtH) Order Number 9206. FABULOUS FM STEREO TOO 2 channels to hear the outside world. Here's where you can really hear the The stereophones are the latest Sam- difference. The Solo provides FM recep- arium Cobalt mylar® diaphragm type that tion that is incredible. We think you'll deliver earth shaking thunderous sound DAK get more and cleaner FM stations than with such precise definition and detail, INDUSTRIES INCORPORATED with any other personal stereo. that music is almost three dimentional. TOLL -FREE 1- 800 -423 -2636 But don't take our word for it. Test it BUT IT'S THE SOUND f busy, after hours, on weekends or in CA yourself. Start at the bottom of the dial Take the KLH Solo to your local HiFi CALL TOLL-FREE ...1- 800 -228 -1234 and compare station to station with any store. Compare its dramatic sound and 10845 Vanowen St., N. Hollywood CA 91605 Circle No. 67 on Free information Card

www.americanradiohistory.comAmericanRadioHistory.Com Computers&Electronics AUGUST 1983 VOLUME 21, NUMBER 8

FEATURE ARTICLES

A SUPER CHIP FOR NEXT -GENERATION 30 PERSONAL COMPUTERS Tony Zingale /A look at Intel's upcoming iAXP 188 CPU.

COMPACT DISC DIGITAL AUDIO SYSTEMS 40 David Ranada /How the new digital audio 4.7" playback record system works.

HIGH -GRADE DATA CONVERTER FOR THE 63 APPLE II Robert C. Nicklin /Part 2: Checkout, calibration and use.

PRINTERS FOR SMALL COMPUTERS 1 Al Burawa /Guidelines to buying impact -type printers. COLUMNS THE SOUL OF CP /M 80 M. Waite & R. La fore /Part 4: The most hidden part of CP /M -the BIOS. 12 COMPUTER VIDEO GAMES LEARNING 16 -BIT MICROCOMPUTER TECHNOLOGY 93 George Meyerle /Part 6: How to use machine language LES SOLOMON ON COMPUTER HARDWARE programming. 22 The "Truly Portable" Sinclair /Timex.

9 TELETEXT EXPERIMENTS BY NETWORKS 24 COMPUTER SOURCES Leslie Solomon /Providing worldwide software distribution.

THE ELECTRONICS SCIENTIST ENGLISH BROADCASTS AUDIBLE 96 Forrest M. Mims, III/Flat Panel Displays /A Tunable 10 1 IN NORTH AMERICA /Glenn Hauser 60 -Hz Hum Filter.

EQUIPMENT REVIEWS DEPARTMENTS

MAGNAVOX MODEL FD1000SL COMPACT 5O DISC PLAYER EDITORIAL /Art Salsberg 4 Friendly Computers.

RADIO SHACK TRS-80 MODEL 4 53 6 NEW PRODUCTS 60 RADIO SHACK MC -10 MICRO COLOR COMPUTER 104 COMPUTER MART /ELECTRONICS CLASSIFIED

MICROBUFFER II PRINTER INTERFACE FOR 78 APPLE II 120 ADVERTISERS' INDEX

COVER ART BY JAMES HEGEDUS

August 1983, Volume 21, Number 8. Published monthly by Ziff -Davis COPYRIGHT c 1983 BY ZIFF -DAVIS PUBLISHING COMPANY. All rights reserved. Computers & Electronics (ISSN 0032 -4485) A. Abrams, Secretary. One year subscription rate for U.S. and Possessions, Publishing Co., at One Park Ave., New York, NY 10016. Richard P. Friese, President; Selwyn Taubman, Treasurer, Bertram New York, N.Y. 10016 and at additional mailing offices. Authorized as $15.97; Canada, $20.97; all other countries, $23.97 (cash orders only, payable in U.S. currency). Second Class Postage Paid at including ELECTRONICS WORLD trademark registered. Indexed in the second class mail by the Post Office Dept, Ottawa, Canada, and for payment of postage in cash. POPULAR ELECTRONICS Photography, Skiing, Stereo Review, Electronic Experimenter's Handbook, and Tape Reader's Guide to Periodical Literature. Ziff -Davis also publishes Boating, Car and Driver. Cycle, Flying, Popular P.O. Box 2774, Boulder, CO 80302. Please allow at least eight weeks for Recording & Buying Guide. POSTMASTER: Send address changes to COMPUTERS & ELECTRONICS. Circulation Dept. may not be reproduced in any form without permission. Requests for change of address, enclosing, if possible, an address label from a recent issue. Permissions. Material in this publication New York, NY 10016. permission should be directed to Elizabeth Amado, Rights and Permissions, Ziff -Davis Publishing Co., One Park Ave.,

2 Computers & Electronics

www.americanradiohistory.comAmericanRadioHistory.Com IF PERSONAL COMPUTERS ARE FOR EVERYBODY, HOW COME THEY'RE PRICED R OBO?

A personal computer will be far more is supposed to be a ..ß,t,.4, challenging than computer for persons. those you could Not just wealthy ever play on a persons.Or whiz -kid * game machine alone. persons. Or privileged And as great as all persons. $1395" 5999` $135 this sounds, what's III 16K But person persons. APPLE® Ile 64K TRS-80' IBW PC 64K even greater-sounding In other words, all the persons whom other home computers can't. Including is the orice. Its hundreds of dollars less Apple, IBM, and Radio Shack seem to some of those that cost a lot more. than that of our nearest competitor. have forgotten about (including, most (Take another look at the three comput- So while other companies are trying likely, you). ers above.) to take advantage of the computer But that's okay. Because now you can By itself, the Commodore 64 is all revolution, it seems to us they're really get a high -powered home computer the computer you'll ever need. Yet, if taking advantage of something else: without taking out a second mortgage you do want to expand its capabilities Their customers. on your home. some day, you can do so by adding a *Manufacturers' suggested list prices as of March 20. 1983. Monitor included with TRS-80 Ill only. Commodore Business It's the Commodore 64. We're not full complement of Commodore pe- Machines. PO Box 50CR, Conshohocken. PA 19428; talking about a low- priced computer that ripherals Such as disk drives. Modems. Canada -3370 Pharmacy Avenue, Agincourt. Ont.. Can. M1W 2K4. can barely retain a phone number. And printers. We're talking about a memory of 64K. You can also play terrific games on Cr. commodore Which means it can perform tasks most the Commodore 64. Many of which Apple is a registered trademark of Apple Computer. Inc. COMPUTER TRS -80 is a registered trademark of Tandy Corp IBM is a registered trademark of International Business Machines Corp.

COMMODORE 64. UÑDER $600. cenirt buy a better computer at twice the price

Circle No. 29 on Fr ttormatio-t Card www.americanradiohistory.comAmericanRadioHistory.Com EDITORIAL tions before the TV progressed into its ucts like the mouse, touch pad, light friendly mode. pen, and touch -sensitive video screen. How about an electronic typewriter? In the software area, authors are using Usually it's a cinch to slide paper into metaphors and icons, and, in general, a the machine, turn it on, and produce more graphic approach to the interface hard copy. Truly a friendly machine between man and machine. you might say. But how about when you Machines such as Apple's Lisa have try to take advantage of some of its spe- taken a giant step in the direction of the cial features, such as automatic tabs and friendly computer. Of the less- expensive error correcting-or what about the ba- machines, Epson's QX -10 and Radio sics such as setting margins and center- Shack's Model 100 appear to be moving ing copy? Does a typewriter seem a little in the right direction with important ap- less friendly now? Let's also mention plications packages built in. Current that both the TV and the typewriter are machines such as the IBM Personal "dedicated" machines, meant to do one Computer and the Commodore 64 will specific job. become more friendly with the addition Before we return to our original ques- of software such as VisiCorp's VisiOn, tion, let's look at the computer in con- which is an easy -to -use window-orient- Friendly Computers trast to the other machines. Firstly, the ed software system, and Commodore's computer is not a dedicated machine. It Magic Desk, which uses pictorial im- ARE computers "friendly "? I suppose if can handle a wide variety of tasks as we ages to convey information to the user. I asked that question of 100 people, 99 all know. Secondly, when a computer is Are computers friendly? The answer would probably respond with a re- used to accomplish a task, the user usu- right now is no. Will they be more sounding "No!" But what is a friendly ally wants it to perform many sophisti- friendly in the future? Yes, definitely. computer anyway? Let's dodge the cated functions. Take word processing Will they ever be friendly in the same question for a bit, and examine some as an example. We are not satisfied to sense as a TV or typewriter? Probably other supposedly friendly machines. place a sheet of paper in a printer and not. But then again, you can never hope The first one to come to mind is the use the computer's keyboard to produce to accomplish with a TV, typewriter, or television receiver. Is it truly friendly? hard copy. We want the computer to do any other dedicated and "dumb" ma- Consider TV's purpose: to bring enter- all the normal tasks like setting mar- chine the same things you can accom- tainment and information into the gins, centering, etc. We also want it to plish with a computer. home. Now how much effort does it check spelling, move paragraphs take to accomplish this purpose? Just around, add footnotes, and maybe even turn on a switch -very friendly. How- suggest (thesaurus -like) possible alter- ever, think back to the time when you nate words to use. No wonder it seems first bought the TV. If it had a mechani- unfriendly at times! cal tuner, you just plugged it in, turned But hardware manufacturers and ate Zza,7 it on, and selected a channel. But if it software authors are really striving to had pushbutton electronic tuning, you make the computer more friendly. In had to set (or fine tune) the desired sta- the hardware area, we are seeing prod-

WILLIAM S. DAVID Comp«tersalectronies Consumer Computers Publisher formerly Popular Electronics Electronics Magazine Division ARTHUR P. SALSBERG Larry Sporn President Editorial Director J. Scott Briggs Vice President, Marketing Carole Mandel Vice President, Circulation LESLIE SOLOMON and Technical Director Editorial Executive Offices Eileen G. Markowitz Vice President One Park Avenue General Manager JOHN R. RIGGS New York, New York 10016 Managing Editor 212 725 -3500 Peter J. Blank Creative Director EDWARD I. BUXBAUM Ziff-Davis Publishing Company Art Director Sales Offices Richard P. Friese President Albert S. Traina President, Consumer ALEXANDER W. BURAWA New York Office Senior Editor Magazine Division Tom Ballou 212 725 -3578 Furman Hebb Executive Vice President JOSEPH DESPOSITO Ken Lipka 212 725 -3580 Paul H. Chook Executive Vice President Technical Editor Marketing and Circulation STANLEY VEIT Midwestern Phillip T. Heffernan Senior Vice Presidents Technical Editor Suite 1400, 180 N. Michigan Ave., Sidney Holtz ANDRE DUZANT Chicago, IL 60601 312 346 -2600 Edward D. Muhlfeld Technical Illustrator Sales: Robert Vanek Philip Sine CARMEN ROBLES Baird Davis Vice Presidents Production Editor Western George Morrissey Selwyn Taubman Treasurer NEWMAN J.E.M. Associates JEFF Bertram A. Abrams Secretary Editorial Assistant Francisco Bay Office Park Contributing Editors: 1750 Montgomery Street Editorial correspondence: COMPUTERS & ELEC- Walter Buchsbaum, Len Feldman San Francisco, CA 94111 415- 989 -4643 TRONICS, 1 Park Ave., New York, NY 10016. Editorial Glenn Hauser, Julian Hirsch Joe Mesics contributions must be accompanied by return postage and Forrest Mims will be handled with reasonable care; however, publisher Representation in Japan assumes no responsibility for return or safety of manu- scripts, art work, or models submitted. J.S. Yagi ABC: Iwai Trading Co., Ltd. The publisher has no knowledge of any proprietary 603 Ginza Sky Heights Bldg. rights which will be violated by the making or using of any Member Audit Bureau items disclosed in this issue. of Circulatio.is 18 -13, Ginza 7 -Chome Tokyo, Japan 104

4 Computers & Electronics

www.americanradiohistory.comAmericanRadioHistory.Com Quantity Discounts Available Wabash diskettes are packed 10 disks to a carton and 10 cartons to a case. The economy bulk pack is packaged 100 disks to a case without envelopes or labels. Wabash Please order only in increments of 100 units for quantity 100 pricing. With the exception of bulk pack, we are also willing to diskettes accommodate your smaller orders. Quantities less than 100 units are available in increments of 10 units at a 20% surcharge above our 100 unit price. Quan- $1.29 each: tity discounts are also available. Now get Wabash Order500 or more disks at the same time and deduct 1%; 1,000 or Quality at a CE Price more saves you 2 %; 2,000 or more saves 3%; 5,000 or more saves 17 For over years, Wabash has been making high quality 4%; 10,000 or more saves 5 %; 25,000 or more saves 6 %; 50,000 and dependable computer products. Wabash diskettes or more saves 7 %, 100,000 or more saves 8 %, 500,000 or more are made to provide error -free performance on your com- saves 9% and 1,000,000 or more disks earns you a 10% discount puter system because every diskette has been totally and off our super low quantity 100 price. Almost all Wabash diskettes hypercritically tested. Since you can now buy Wabash are immediately available from CE. Our efficient warehouse computer products directly from CE, the world's largest facilities are equipped to help us get you the quality product you distributor of magnetic media, you can now get maximum need, when you need ill. If you need further assistance to find the flexible disk that's right for you, call the Wabash savings on every order. You can compatibility even order toll -free. hotline. Dial toll-free 800-323-9868 and ask for your compatibility New Wabash Six Year Warranty representative. In Illinois or outside the U.S. dial 312 -593 -6363 The quality of Wabash diskettes is stressed throughout between 9 AM to 4 PM Central time. the entire manufacturing process. Aftercoating, all Wabash Buy Wabash Diskettes with Confidence diskettes go through a unique burnishing process that To get the fastest delivery from CE of your Wabash computer gives each diskette a mirror -smooth appearance. Wabash products, we recommend you phone your order directly to our then carefully applies a lubricant that is specially form- Computer Products Division and charge it to your credit card. Be sure to calculate your price ulated to increase diskette life. Then, to keep using the CE prices in this ad. Written out foreign purchase orders are accepted from approved government particles, a unique heat agen- seal bonds the jacket and liner cies and most well rated firms at a 30% surcharge for net 30 together to help prevent contamination. After 100% hyper- billing. For maximum savings, your order should be prepaid. All critical testing and certification, Wabash then packages sales are subject to availability, acceptance and verification. All each diskette, (except bulk pack) in a super strong and sales are final. All prices are in U.S. dollars. Prices, terms and tear resistant Tyvek° evelope. The final Wabash product is specifications are subject to change without notice. Out of stock then shrink -wrapped to insure cleanliness and reduce items will be be placed on backorder automatically unless CE is contamination during shipment. Wabash diskettes are so instructed differently. Minimum prepaid order is $50.00. Mini- mum purchase order$200.00. All shipments are F.O.B. Ann Arbor, very reliable that Wabash now offers a six year warranty in Michigan U.S.A. No COD's please. Non case of in -certified and foreign defects materials orworkmanship on all diskettes checks require bank clearance. purchased directly from Communications Electronics. For shipping charges add $8.00 per case or partial New...Wabash Diskette Duplication Services case of 100 8 -inch flexible disks or $6.00 per case or Communications Electronics has teamed up with Wabash to partial case of 100 51/4 -inch mini -diskettes for U.P.S. provide a single- source solution for the diskette duplication ground shipping and handling in the continental U.S.A. requirements of software developers, OEM's and distributors. All service is in- house, to give you fast, dependable service. In Mail orders to: Communications Electronics, Box 1002, most cases, delivery can be completed in five days. Whether Ann Arbor, Michigan 48106 U.S.A. If you have a Visa you require 100, 1,000, or 10,000 copies per week, call CE or Master Card, you may call and place a credit card order. first for a no obligation price quote. For additional information, Order toll -free in the U.S. Dial 800 -521 -4414. In Canada, please write us on your letterhead with your requirements. order toll -free by calling 800 -265-4828. If you are outside CE quant. the U.S. or in Michigan SAVE ON WABASH DISKETTES 100 price dial 313- 994 -4444. Telex anytime Product Description Part # per disk (S) 810 -223 -2422. Order your Wabash diskettes today. 8" SSSD IBM Compatible (128 B /S, 26 Sectors) F111 1.89 Copyright E1983 Communications Electronics" Ad #U12483 8" SSSD Shugart Compatible, 32 Hard Sector F31 A 1.89 8" SSDD IBM Compatible (128 B /S, 26 Sectors) F131 2.39 MEMBER 8" DSDD Soft Sector (Unformatted) F14A 2.99 Mastercard 8" DSDD Soft Sector (256 B /S, 26 Sectors) F144 2.99 DIRECT MAIL 8" DSDD Soft Sector (512 B /S, 15 Sectors) F145 2.99 MARKETING ASSOCIATION 8" DSDD Soft Sector (1024 B /S, 8 Sectors) F147 2.99 51/4" SSSD Soft Sector w /Hub Ring M1 1 A 1.49 u 5'/4" Same as above, but bulk pack w/o envelope M11 AB 1.29 OrderToll-Free! wabash 51/4" SSSD 10 Hard Sector w /Hub Ring M41 A 1.49 5'/4" SSSD 16 Hard Sector w /Hub Ring M51A 1.49 800 -521 -4414 error -free 51/4" SSDD Soft Sector w /Hub Ring M13A 1.79 In Michigan 313 -994 -4444 diskettes 5'/4" Same as above, but bulk pack w/o envelope M13AB 1.59 TM 5'/4" SSDD 10 Hard Sector w /Hub Ring M43A 1.79 51/4" SSDD 16 Hard Sector w /Hub Ring M53A 1.79 51/4" DSDD Soft Sector w /Hub Ring M14A 2.69 5'/4" Same as above, but bulk pack w/o envelope M14AB 2.49 /COMMUNICATIONS 5'/4" DSDD 10 Hard Sector w /Hub Ring M44A 2.69 51/4" DSDD 16 Hard Sector w /Hub Ring M54A 2.69 ELECTRON ICSTM 51/4" SSQD Soft Sector w /Hub Ring (96 TPI) M15A 2.59 51/4" DSQD Soft Sector w /Hub Ring (96 TPI) M16A 3.69 51/4" Tyvek Diskette Envelopes - Price per 100 Pack TE5 12.00 Computer Products Division SSSD = Single Sided Single Density; SSDD = Single Sided Double Density; DSDD= Double Sided Double Density; SSQD= Single Sided Quad Density; 818 Phoenix Box 1002 Ann Arbor, Michigan 48106 U.S.A. DSQD = Double Sided Quad Density; TPI = Tracks per inch. Order TOLL-FREE 800- 521 -4414 or outside U.S.A. 313 -994-4444 CIRCLE NO. 19 ON FREE INFORMATION CARD

www.americanradiohistory.comAmericanRadioHistory.Com NEW PRODUCTS

RCA ALL -PURPOSE TERMINALS RCA's line of all- purpose terminals (APT) for multi- database timesharing and dedicated, direct computer- connected applications have either full - stroke or membrane keys and come with or without a 12" terminal. Features include menu -controlled operation; programmable "personality" to match communication requirements for each database; built -in, direct -connect 300 -baud modem; tone or pulse auto -dialing of up to 26 stored phone num- I i, I I I l bers; and automatic log -on. Standard 60 -key alphanumeric keyboard in- rriiilti Ì cludes two user selectable keys and there is also a 16 -key calculator pad. Full- keystroke with terminal (shown): $598. Circle No. 83 on Free Information Card

FULL LOGIC REVERSE MAINTENANCE MONITOR

CAR AUDIO CASSETTE RECEIVER AM and 6 FM illuminated station presets, Yamaha's FM Auto- The YCR -900 cassette receiver from Yamaha features 18 matic Noise Control, and adjustable muting threshold. Specs: W /channel output into 4 ohms, both channels driven. It also has sensitivity, 17.3 dBf; 50-dB quieting, 20.7 dBf; alternate channel electronic synthesizer tuning, automatic reversing, and a bot- selectivity, 80 dB; S/N, 65 dB; frequency response, 30- 15,000 tom- loading tape transport with full logic control. Tuner section Hz. $550. has automatic "seek" and manual tuning in both directions, 6 Circle No. 84 on Free Information Card

NETWORK CAPABILITY IN PORTABLE COMPUTER TeleTote I, from TeleVideo Systems Inc, is claimed to be the first portable computer with the capability of being connected to a network. An optional RS -422 port enables it to be linked to a TeleVideo network for access to shared files, printers, and electronic mail. Weighing 25 lb, it has a 9" display screen with 640 by 240 graphics resolution. Display is 24 lines by 80 characters. It has a Z80A CPU, 64K RAM, expandable to 128K, a 368.6K (formatted) 51/4" floppy -disk drive, a SuperMouse port for cursor manipulation, and two RS232 printer /modem ports. $1499. Circle No. 86 on Free Information Card BRIEFCASE COMPUTER WITH DISK DRIVE The Pied Piper has a full ASCII keyboard, is built around the Z80A CPU, and has an integral slim -line minifloppy disk drive with 748K bytes (formatted) and accommodations for a second 748K -byte floppy drive. The STM Electronics Corp. computer has 64K RAM, 4K ROM, 2K video display buffer, and 2K ROM for character generation. A 5M- or 10M -byte hard -disk subsystem can be added. It can interface a standard CRT monitor providing a 24 -line by 80- character format. An r -f modulator is also available. For hard -copy printout, there is a parallel port for Centronics /Epson -style printers. The Pied Piper operates on CP/M 2.2 and the Perfect Software package (word processing, spelling dictionary, electronic spreadsheet, and data filing/merging system) is included. Di- mensions:4" X 20" X 11 "; weight: 12.5 lb. $1299. Circle No. 85 on Free Information Card

www.americanradiohistory.comAmericanRadioHistory.Com 16K TIMEX SINCLAIR 1500 The Timex Sinclair 1500 features 16K RAM (expandable to 32K), extended BASIC, and 40 moveable keys. Each key can perform as many as six functions including key- word entry. The 1500 is said to be compatible with all of the peripherals and software available for the TS1000. Additionally, instant -load software cartridges can be inserted into a low -cost interface that plugs into the computer. $79.95. Circle No. 88 on Free Information Card

LOW-COST DOT-MATRIX "BANANA" The Gorilla / "Banana" dot -matrix printer, features 50 cps print speed, dot -addressable graphics, 5 X 7 dot matrix, tractor paper feed, self -inking ribbon cassette, parallel or serial interface, and 10" carriage. From Leading Edge Products, it can print either 10 or 5 cpi, the former providing 80 columns. Printhead pressure is adjusted with a 7- position switch. Four special character sets are included for US, UK, Germany, and Sweden. Has rotating thumbwheel advance and single- hammer construction. Weighs 10 lb. $249.95. Circle No. 87 on Free Information Card

PORTABLE COMPUTER IS IBM -PC COMPATIBLE The Columbia VP is an 8088 -based microcomputer said to provide IBM compatibility in a portable package. It features a 9" video monitor, two 5 i/a" half -high floppy -disk drives, IBM -standard keyboard, 128K RAM (expandable to 256K), an RS232 interface, and parallel printer interface. Video display is 600 X 200 or 320 X 200 pixels. Disk drives are 320K double-sided, double- density. Dimensions: 18" X 14" X 8 "; weight: 32 lb. $2995. Circle No. 89 on Free Information Card

TELEVISION WATCH Claiming it to be the first television watch, Seiko has introduced a digital wristwatch that also contains a 1.2" LCD TV screen and weighs less than 2 oz. Ac- companying the wrist unit are a pocket -size power - pack /tuner and stereo headphones (which also contain the antenna). The set will receive all 82 vhf and uhf channels and FM stereo radio. The display has 31,920 elements. $495. Circle No. 90 on Free Information Card

ENHANCED DAISY -WHEEL PRINTER

Smith -Corona's TP -II has a dual interface for RS232 or Centronics operation; a 10/12 -pitch ASCII 93- character printwheel; panel switches for form fed, line feed, and self test; interior switches for baud rate, parity, and character length, and for foreign languages; automatic under- score; programmable margins and tabs; and 256- character buffer. Print speed is 12 cps. $895. Optional tractor feed, $149. Circle No. 91 on Free information Card

August 1983 7

www.americanradiohistory.comAmericanRadioHistory.Com "I built this 16 -bit computer and saved money. Learned a lot, too:'

Save now by building the Heathkit H -100 The H -100 is easy to build the step -by -step Heathkit ycurself. Save later because your computer manual shows you how. And every step of the way. you investment won't become obsolete for have our pledge "We won't let you fail:' Help is as close many years to come. as your phone, or the nearest Heathkit Electronic Center. And what better way to learn state -of- the -art computing Save by bui ding it yourself. You can save hundreds of techniques than to build the world's only 16-bit 8-bit dollars over assembled prices when you choose the new computer kit? To run today's higher- speed. higher -per- I- -100 16 -Bit /8 -Bit Computer Kit money you can use formance 16 -bit software, you need an H -100. It makes a to buy the peripherals and software of your choice. significant difference by processing more information at H -100 SERIES COMPUTER SPECIFICATIONS: faster speeds. DIAGNOSTICS: USER MEMOFY: Dual microprocessors for power and compatibility. The 128K -768K bytes Memory self -test H -100 handles both high -performance 16 -bit software MICROPROCESSORS: on power -up 16 -bit: 8088 AVAILABLE SOFTWARE: and most current Heath Zenith 8 -bit software. 8 8085 Z -DOS (MS -DOS) -tit: Want room to grow? The H -100 s standard 128K byte CP M -85 DISK STORAGE: Random Access Memory complement can be expanded Built -in standErd Z -BASIC Language 5,25 disk drive, Microsoft BASIC to 768K bytes - compared to a 64K standard for many 320K bytes,disk Multiplan desktop computers. SuperCalc KEYBOARD: WordStar And the industry- standard S -100 card slots support Typewriter -style, MailMerge memory expansion and additional peripheral devices . 95 keys.13 Data Base furction keys, Manager increasing future upgradability of the H -100. 18 -key numeric pad Most standard High -capacity disk storage, too. The H -100 s 5.25" floppy 8 -bit CP; M GRAPHICS: disk drive can store 320K bytes on a single disk. The Always in gray hics mode Software 640h 225v resolution: computer also supports an optional second 5.25 "' and up to eight colas external 8 floppy disk drives. And an optional multi - are available megabyte internal Winchester disk drive COMMUNICATIONS: will be available in the near future. Two RS -232C Serial Interface Ports and oie parallel pert

'23K bytes standard. Optional. The H -100 gives me the most for my computer dollar!

ipassMAtilir _. ; .i

www.americanradiohistory.comAmericanRadioHistory.Com Learn from outstanding documentation. One of the most important parts of any computer system is documentation - and Heathkit documentation is among the industry's best. Our instruction and operating manuals are fully detailed, in tie world -famous Heathkit tradition. Learn Ly doing. Many of our software programs come with a complete set -up and operating manual. More complete than most other software documentation each manual not only tells you what the program will do - it shows you the easiest way to accomplish each task. We bac you all the way. With Heathkit computer products, technical assistance and expertise is as close as your to ephone - or the nearest Heathkit Electronic Center.- Comple-e -echnical assistance and service is Critical circuits ere pre -assembled, making the H -100 available at over 60 locations nationwide. easier and faster to build! Buy from a leader. When you ct-oose a Heathkit com- world's Want beautiful high- resolution graphics? You can create puter, you get the backing and reliability of the You extensive charts, drawings, graphs and symbols to meet leader in quality electronic kits for over 50 years! can court on us for quality service, reliability and value your needs - using the H -100 's bit - mapped graphics at kit that give you more computer for your dollar! and its 640 x 225 pixel video display. pries the H -100 in 3c-ion. Visit your nearby Heathkit Elec- The H -100 gives you total communications flexibility. See which Three interface ports let you plug in dot -matrix and tronic Center. has the world's first letter -c uality printers, as well as other periphera s. 16 -biti8 -bit computer Compare the H -100's exceptional capabilities kit, peripherals and with other desktop computers: software programs on IBM display. See your tele- Heathkit Personal apple phone white pages for COMPUTE- H -100 Computer III the nearest store loca- MICROPROCESSORS: tion. Or mail the cou- 16 -bit. 8088 8088 - 8 -bit: 8085 6502 pon today for a FREE. RANDOM ACCESS MEMCRY full -color Heathkit Always i i graphics mede, you Minimum: 128KB 16KB 128KB computer catalog. Maximum 768KB 576KB 256KB can control each of the H- 1100's

FLOPPY D SK STORAGE 144.000 screen dots! (Colo - Per Disket e. 320KB 320KB 140KB graphics optional) Maximum nternal 640KB 640KB 140KB 8 Floppy Support: Standard - - EXPANSIOI4 SLOTS: Five S -100 Five (three Eight r (four availatlet available) CLIP COUPON AND MAIL TODAY TO: Heath Company, Dept 310 -084 LO PORTS Benton Harbor, MI 49022 Parallel: 1 Optional

Serial: 2 Optional 1 Please send my FREE Computer Catalog, with details on t H -100

OPERATING SYSTEMS: CP M -85. CP M -86 Aprle SOS City -_ State 2 -DOS (MS -D3E) PC -DOS (MS -DOS) UCSD P- System CP -218R1 Zip Information current as or 8,31182. - E xternal disk storage available soon. L Learn by building. When you build and operate the -1 -100. Heathkit Electronic Centers are units of Veritechnology Electronics Corporation. learn more this sys- Heath Company and Veritechnclogy Electronics Corporation are subsidiaries of you about sophisticated computer Zenith Rad o Corporatioi. Prices, product ava lability and specifications are tem and its unit ue 16 -bit :8 -bit software capabilities. subject to change withou- no:ice.

Circle No. 24 on Free Information Card

www.americanradiohistory.comAmericanRadioHistory.Com COMPUTER VIDEO GAMES

are there: variable page parameters, Once in a while, we come across a Hands-On Reviews rapid scroll, find and replace, etc. And new company with some really brilliant of Recently it's easy to use. computer game concepts. This is one of The principal problem with the those rare cases. The emergence of Elec- Released Q.B.F.-as with most anything you run tronic Arts with its line of "thinking" Game Software on the VIC -20-is the fact that the com- computer games may show the way for puter has a nonstandard printer output a lot of successful entries in the future. ONE of the more intriguing develop- and you need a special interface con- We've had a peek at some of the other ments for what are traditionally home - verter such as the one from Cardco games to come from this company, and type computers is the rash of "serious (about $79) that lets the computer run we think they'll be real winners. software" products coming out for such with any parallel printer. It is a cheap Archon is a combination of several machines as the Atari 800 and the Corn - and quick way to get word processing modore VIC -20. Foremost as members on a low -cost computer. of this group are the several word -pro- Another VIC -20 entry, Wordcraft 20 cessing programs we've seen -some from U.M.I. (another game house), fairly venerable, others brand new. costs a bit more (about $150), but has Atari has had its own WP for quite a some additional features that make up while; and though it is more complex for the higher price tag. For one thing, it than most, it comes with a tutorial tape doesn't require that special interface to cassette that helps make life easier for run the printer. Instead, it has specific the complete neophyte. Atari also re- programming addresses built in so it ports a new, improved WP program. will drive just about any parallel printer We haven't seen it yet, but it's supposed right from the VIC's user port. to be extra -easy to learn. Also, the Wordcraft has a 40- column One that's been out for a while and screen display converter built into its types of games. It starts out looking that we found especially easy and quick circuitry, which makes the VIC some- something like a chess board, except the to learn is DataSoft's "Text Wizard." what more feasible as a word processor players are mostly fantasy -allegorical The various command functions are a than does its normal 23- column display. characters such as the wizard, sorceress, breeze to assimilate, and the supplier You do need a special connecting cable unicorn, phoenix, shapechanger, and has thoughtfully provided a quick- refer- for most typical printer hookups, but others. Each playing piece, called an ence crib card-something that would any good computer store will make this "icon," has particular move limits that be very helpful from every software sup- up for you. When you compare it can make on the board; and each has plier. Maybe they did it this way be- Wordcraft with Q.B.F., neither one its own special way of doing battle. cause they're primarily a game vendor comes off with a particular price edge, This is best played as a two -player and used to putting concise instructions since the Wordcraft has features built in game, although you may elect to play on a card in the package. that are otherwise available only with against the computer -in which case, A brand new one is the "Bank Street additional hardware when you use the you may not stand a chance. Each icon Writer," just landed from Broderbund Q.B.F. But the latter system has a big has a specific battle weapon, and you Software. It comes with a tutorial on the attraction -the low initial cost, which engage an enemy piece by trying to oc- reverse side of the diskette. To retrieve makes it painless to buy and add to cupy the same square on the chessboard the tutorial, play the diskette upside - later. that the enemy is on. When you press down-a feat that's possible with the One thing about all these word your fire button to "engage," the screen Atari disk drive. Unlike most other low - processors -whether they're for the changes, and the two of you square off cost WP programs, Bank Street Writer Atari or the VIC -a decent -quality on a field of battle that has many trees presents the screen display the way it monochrome monitor is important in and shrubs to act as obstacles and will appear on the printed page instead order to read print on the screen easily. shields. of jumbling it all together in one mish- Substituting an excellent amber -and- Some pieces, like the knights and gob- mash. This is a definite plus, and the de- black- screen monitor for a color -TV set lins, are sword -swingers and club wield- signers are to be congratulated on their made an enormous difference! Both the ers, so their range of effectiveness is lim- thoughtfulness and thoroughness in VIC and the Atari have a composite vid- ited. But when you play against the putting this package together. eo output at a five -pin DIN connector, computer, watch out for those lowly For the VIC -20, we have two entries so attaching the monitor was no prob- goblins; they're fast and mean! Other of import: the Quick Brown Fox and lem at all. All that was needed was a $5 icons have long -range weapons such as Wordcraft 20. They're both on plug -in DIN -to -RCA adapter. fireballs, lightning bolts and arrows. ROM cartridges. The Q.B.F. is super - The phoenix has a field of fire, while the and sorceress (on opposing cheap (about $65), a price probably ARCHON wizard made possible by the fact that it's been teams) can throw fireballs. They can around for a while and just recently sur- Diskette for Atari 400/800 also cast a number of very useful spells faced in a VIC version. In its unexpand- Electronic Arts, 2755 Campus Drive, such as teleport, heal, revive (a dead 415 -571 -7171. ed version, the ROM cart provides San Mateo, CA 94403, icon), summon an element (wind, water, for creating files. $40.00 fire, etc. to act as combatants), imprison about 2K of space Graphics * * ** (a troublesome opposing icon), or re- Adding memory expansion is a big help Gameplay * * ** used just here. Like most such programs, it relies Sustained interest **** verse time. Each spell can be heavily on your willingness to save the Type: Joystick strategy /adventure once during a game, and it's important goodies on a cassette tape at your earli- game to remember what you have left and to est convenience. All the usual features Memory Required: 32K (Continued on page 16)

12 Computers & Electronics

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Circle No. 48 on Free Information Card 3M www.americanradiohistory.comAmericanRadioHistory.Com How to quickly re If you'd like to turn the agony pleasure -all with an Apples III General Ledger, Accounts of small business bookkeeping Personal Computer. Payable, Accounts Receivable into the ecstasy of total control, Attain instant and Payroll -all in one package. you've come to the right place. financial status. Meaningfully, that means you Because even if you're starting can turn numbers into answers. with a shoe box full of invoices An Apple III, teamed with the With BPI, your Apple III can or a pile of checks hiding under a BPI General Accounting Package, give you a snapshot of your pile of deposit slips, we can tell can put every basic accounting company's financial condition, you how to centralize, organize function right at an up-to-the -instant and monitor all that information, your fingertips. balance sheet. It and manipulate it in ways that Technically, can also generate will make your business a that means instant and detailed 9 a")/,,,,e reports e bk"1":1)í', It`,b , lkfor, Agt

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www.americanradiohistory.comAmericanRadioHistory.Com gain your balance. on your customers and vendors. The BPI General Accounting results will make an important So you know who owes whom, Package also lets your income statement to everyone you deal how much, and how come. statements be coded by location, with - Including your banker. And just how well your cash department or product line. So flow is flowing. you know where your money's More ways Apples pay. And where to give credit where coming from. There are more people in more credit is due (a customer inquiry And where it's not. places doing more things with

Ichiban Fish Supply Company Ichiban Fish Supply Company Ichiban Posh Supply Company Consolidated Income Statement Me-chandise Purchased By Du? Date Asf Current Comparative As Of 85 31 83 15,31o8; Accounts Receivable Ledger Page I Periods Ending May 31, 1983 and May 31, 1982 tendon Invoice Acct Customer Balance Current May 31. 1983 t May 31, 1982 % Date No Name Number No Detail Net Amt No Name Folio Forward Month Balance

Income Contract Sales 52.818.82 91.3 44,176 52 92 7 851283 1 Herring World 35278532 5818 -81 581.23 Retail Sales 5816.88 8 7 3,588.88 7 3 Due 86,03,83 1 Poser's Sols Food 892 79 Invoice 124 IR 212 23 Total Income 57,834 96 188 8 47,676 52 188 6 8515,83 2 Consolidated Cod 4562 5818 -81 209.36 156 56 Due 8645í83 Invoice 199 Invoice .326 828.08 Cost of Sales CÁ 80- 8585,83 3 Levy Sushi Farm 212 5818 -81 459 08 05'15,83 250 Cost of Contract Sales 37,338 88 64 6 31,886 55 66 7 Due 86'85/83 1,831 58 Cost Of Retail Sales 4,879 85 8 4 3,409 35 7 2

85,8583 4 Mussel Ben, Inc. 657 5818 -81 68 26 Total Cost of Sales 42,289 85 73 8 35,215 98 73 9 Due 0685/83 Cross Profit 15,625 RS 27 8 12,468 62 26 1 1,237 85 Total

Your Apple can generate instant income statements It can also allow you to take full advantage of To avoid fishy transactions, you can instantly (with expense ratios) or balance sheets, and let you merchandise discounts. So you'll know whom to pay display customer's payments, charges and current compare them to last month's or year's, then print when to pay, how much to pay- and save a lot of balance. In this case, a few more cans of tuna them out to suit your banker. clams in the process. would put Mr Moser over his $2,000 limit. feature allows you to make credit Make a timely Apples than with any other decisions based on the most statement. personal computer in the world. current information). Add an Apple Dot Matrix or Because for one thing, there's You can also list your Daisywheel printer to your Apple more software for Apples than purchases by discount III, and you can print out your for any other personal computer dates. And take advantage of entire balance sheet in minutes. in the world. So the same Apple them in no uncertain net terms. Or any number of reports, from that handles all your accounting You can even keep payroll records cash receipts to payroll ledger to needs can also handle financial without paying more, because it's income. You can even print spreadsheets, word processing part of the same package. checks and customer statements. and electronic filing. The impressively professional You'll also find programs that Profit from history. are designed specifically for your kind of business. Be it dentistry, In business as in life, architecture or swine herding. experience is the best Of course, the best way to learn teacher. And the Apple /BPI all the ways Apples can help you system can provide you with make better business decisions instant of comparisons is to visit any one of over 1500 this- month- this -year vs. authorized Apple dealers. this- month -last-year, or So drop in. For a full account. this- year-to -date vs. last -year-to -date. So you can quickly spot changing expense apple ratios and make decisions with 20/20 foresight. The most personal computer.

Call (800) 538 -9696 for the location of the authorized Apple dealer nearest you, or for information regarding our National Account Program. Or write Apple Computer Inc., Advertising Department, 20525 Mariani Avenue, Cupertino, CA 95014. © 1983 Apple Computer Inc. Circle No. 35 on Free information Card

www.americanradiohistory.comAmericanRadioHistory.Com ...COMPUTER GAMES

use them before you lose the game. cannon shells explode. Then gauge your traveled to the black asteroid beyond When you lose your Wizard (or Sorcer- approach altitude accordingly. Jupiter's orbit. The android tries to ess) the game is over just as a chess If you succeed in getting through this seize treasures hidden in the labyrinth game ends when your King is screen, you face the deadliest challenge beneath the asteroid's surface. checkmated. of all -the armored robot. I haven't The sound track is ingenious and There are so many built -in, adven- succeeded in getting this far yet, but the amusing, containing the android's ture-like variations and combinations game is exciting and an unbelievable mechanized voice reporting on various that it's really impossible to do them grabber. Just when I thought I had fi- status elements -such as, "Radioactiv- justice in a short review. The game rates nally outgrown all of those outer-space ity present, earthquake potential," and extra high on the scales. type shoot -em -ups, this one had to come "Coke machine operational" (Coke ma- along! It's actually kept me up later than chine???). You find out that it's a real ZAXXON some of my all -time favorites, which I Coke machine, as the android dumps Cassette or Diskette for Atari 400/800 won't mention here. some change into it and then says, DataSoft, Inc., 9421 Winnetka Ave., Like so many computer games, skill "Darn it, I just lost my quarter." Ap- Chatsworth, CA 91311; 213 -701 -5161. develops with time and practice. Unlike parently soda is a lot cheaper once you $39.95 many such games, smaller memory ver- enter the dark asteroid's labyrinthine Graphics ** ** sions are missing some of the refine- treasure house. Gameplay **** ments. The 16K version, for example, The treasures are guarded by armed Sustained interest ** ** Type: Joystick action game has no surface -to -air missiles defending robots, and you need to retrieve keys to Memory Required: 16K cassette; 16K or the enemy fortress. Also, you can't get from one level to the next. There are 32K diskette change your ship's altitude during the two screens-an overall view of the outer -space dogfight with the enemy maze from the top, showing your Zaxxon is already enshrined among fighters. location -and an eye -level three -di- those favorite arcade games that we'd If you have a choice, and especially mensional view of the maze from the like to be able to bring home, and since the price is the same for all ver- top, showing your location -and an DataSoft has finally made it possible. sions, don't get the cassette; it takes for- eye -level three -dimensional view with The game is currently available in three ever to load into the computer. When excellent graphics. In Version 1, a com- versions: a 16K cassette and a diskette using the diskette version, start with the pass pointer indicates which direction with both 16K and 32K versions (one 16K game and play it until you get more you're traveling with the overview of on each side) for the Atari computer proficient. Then switch to the 32K side the maze as your map vantage point. and a 48K disk for the Apple. of the diskette. Also, if you have a Version 2 eliminates the compass and is The game presents a three- dimen- printer /modem interface for your therefore much harder. sional scene as you pilot your attack jet Atari, make sure it's turned off before There are natural hazards-such as fighter through four different screens loading, or you'll find the game erasing absorbing too much radioactivity, or attacking first the enemy's floating for- from RAM each time you lose your getting hit by a blast from a robot tress complete with walls, laser barriers, third attack fighter. guardian. A time bomb can also explode anti -aircraft cannon, and the hazard of catching your android in its blast, and crashing into the very objects you want ANDROID there's an engulfing slime which is very view to blast to smithereens. Your of the Diskette for Atari 400/800 dangerous. Earthquakes come and go at screen is at an angle so you can watch PDI (Program Design, Inc.), 95 East random, knocking down walls and the three -dimensional scenario. You Putman Ave., Greenwich, CT 06830; blocking corridors -often the very ones move your fighter up and down and 203 -661 -8799. $29.95 you wanted to explore. Also, your an- from side to side; your control is com- Graphics * * ** droid can simply run out of energy -in plete, but you can easily get blasted. Gameplay**** all of these cases, the game ends when Finish the first screen (fortress) and Sustained Interest *** your android is destroyed. If you can't you face an armada of defending enemy Type: Joystick maze and action game complete the tasks, you can at least go Memory jet fighters. Screen three is a much more Required: 40K + Atari BASIC for points when new at the game. cartridge difficult fortress with really difficult la- The Captivity version is a straight ser barriers. This is where some fancy Maze lovers will jump into this disk maze/escape game in which you have to flying comes in handy. As with the ar- with both feet. According to the direc- find your way out of the maze in a given cade version, about the only way to tions, it's really two different games: time period. There are 10 versions with gauge your altitude properly for squeez- "Android" and "Captivity" -but in re- a compass and 10 versions without. Ev- ing safely through these barriers is to ality, it's just two different kinds of ery timeyou take a peek at the overhead shoot at the wall and see where your maze games with the same basic view, it costs you points. diskette. Like PDI's earlier release, "Moon - base IO ", this disk is accompanied by a voice -track cassette that plays through your Atari's cassette recorder, if you have one. Unlike Moonbase IO, playing the cassette isn't really necessary; it contains no control tracks for the game - play, but the sound track definitely makes the game more interesting. It supplies the robot -like voice of your remote- controlled Android which has

16 Computers & Electronics

www.americanradiohistory.comAmericanRadioHistory.Com After you ask what it can clo for you now ask what it d0 for you

If you're about to buy Dow Jones/ a personal corn - News Retrieval puter, you need to Service, or a num-

t . t , - consider two basic m""rir t o ,_ ber of other nation issues: needs are now, and what wide information sources. What your í they're likely to be a few years from now. When the time comes for more, That's why the HP -86 has to be your best - ccnsult our 450 -page software catalog. choice. It's got the software and the hardware Chances are, you'll find what you're to go the distance. The HP- 86 looking for. Personal Computer. Software for today and tomorrow. Hardware that expands with your needs. Save $255* on the Personal Productivity Pac. Here's While your computer's ability to expand depends largely a good way to get started. With software on software, naturally, the hardware must keep up. that, if bought separately, would cost you That's why the HP -86 system has a modular design. So $750 ** We're offering it at the reduced you can add a printer or plotter as easily as you hook price of $495** You'll get VisiCalc® PLUS, up a tape deck to your stereo. And operate up to 14 peri- the world-famous electronic spreadsheet pherals at once, if you wish. for "what -if" planning. (The "PLUS" is When you find yourself facing lengthy problems or a Hewlett -Packard bonus: extra programs spreadsheet analyses, simply add more memory - up to to quickly turn your spreadsheet into bar graphs, line 640K bytes. graphs, or pie charts.) Plus WORD /80, for word process- As you demand more of your HP -86, you'll find that ing. And FILE /80, for record keeping without paperwork. it keeps up. Whether you need a broad range of hardware, CP/M`k Buy this plug -in module, and you'll extend your software, or peripherals, the HP -86 makes expansion HP-86 system to accept many popular programs writ- easy, giving you a hard -working system tailored to help ten under the CP/M operating system - programs such solve your specific problems. as WordStar'M and dBASE II.' If you need more good news, try this: The basic system Graphics Presentations. When combined with the is only $2820 ** (128K computer /keyboard, 12" monitor HP 7470A plotter, our graphics software lets you produce and single 31/2" disc drive). professional -quality pie and bar charts, line graphs, text Get a hands -on demonstration of the system that works pages, and overhead transparencies. And you can do it all for you now, and will still be working for you later. in color. For the authorized HP dealer or HP sales office nearest Data Communications. If you decide you want it, an you, call TOLL-FREE 800 -547-3400 and ask for operator optional accessory lets you access The Source, the 96. M -F, 6 a.m. -6 p.m. PST.

'Software savings are based on suggested U.S. list pries and may vary. Suggested retad price. May vary outside U.S. Personal computers & calculators HEWLETT VisiCalc is a registered trademark of VisiCorp. is a Inc. for professionals on the move. CP /M registered trademark of Digital Research, PACKARD WordStar is a registered trademark of MicroPro. dBASE 11 is a registered trademark of Ashton -Tate. PG02320 209D Circle No. 65 on Free Information Card

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August 1983 21

www.americanradiohistory.comAmericanRadioHistory.Com LES SOLOMON ON COMPUTER HARDWARE

isolates the battery from the system. In the circuit shown here, the two di- Thus, the line- operated power supply odes, the Polariod battery, and the runs the computer. If the line-operated physically small POWER switch were fit- supply is removed -either by physically ted together and covered with a layer of unplugging the supply from the wall black electrical tape. A connector was socket or if power fails for any used to interface to the plug at the end of reason -D2 becomes forward- biased, the wall- mounted supply, and a small Dl becomes reverse -biased, and the bat- cable terminated with a suitable plug tery supplies power to the computer. was used to connect the package with Battery power cannot be fed back to the the computer's power input receptacle. wall unit (a possible discharge path) Since solder doesn't adhere very well to since, under these conditions, reverse - the two electrical contacts on the bat- biased Dl acts as an open switch. tery, I used a pair of "bobby" pins that Now, which battery to use? A con- were scraped to make good contact. ventional 9 -V transistor radio type will The taped package can be mounted to A "truly portable" run a minimum computer, but since its the top surface of the computer using Sinclair /Timex 9 V is higher than the approximate 7 V double -sided adhesive tape, with the supplied by the wall -supply that comes output cable plugged into the computer WOULDN'T it be nice to be able to enter with the computer, it will soon run input receptacle. When the wall supply a program in your Sinclair /Timex corn - down to 7 V -a waste of power. Besides, is plugged into the battery package, and puter and, when you remove the ac a conventional 9 -V radio battery is lim- the POWER switch turned on, the system power, have the program remain in ited as to how much current it can deliv- works as normal. When the wall supply memory? This, of course, makes the er over a long period. When RAM or a connector is removed (or wall power Sinclair /Timex a truly portable corn - printer is added to the basic computer, fails), the battery runs the system. puter that can be carried from video ter- the power demands increase rapidly. When the battery runs down, simply slit minal to video terminal (or TV receiver There is one battery that works very the tape, and wire in a new battery. to TV receiver). I'd like to tell you how well, and best of all, you can get it free. you can do it by building a very simple And this battery can deliver 6 V with a Adding a Reset Switch. One of the add -on circuit for your computer. I'll lot of current for quite a long time. small "goodies" not included on the also show you a simple little circuit that I'm talking about the flat battery that Sinclair Timex T1000 computer is a "re- will reset your T1000 when you want to comes in Polariod film packs. If you set" switch to be used when things real- "start over." know anyone with a Polariod camera, ly go berserk. If you do any program- Even you are not interested in porta- ask him to save you the plastic frame ming, you know what that means. To bility, the circuit to be discussed adds that is left after all the film has been add a reset switch to these machines, one other very useful feature -it pro- used up. (The frame is usually thrown connect one end of a slender insulated vides an uninterruptable power supply away.) Break open the plastic enclosure lead to pin 26 of IC3 (Z80) or to the that maintains the computer's data in- and you will find a flat, very thin battery junction of R15 and C5 as shown in Fig. tegrity if it is connected to the wall sock- about 2" by 3 ". Electrical connections 2. Connect one end of a similar slim lead et and commercial power fails. are made via a pair of metallic contacts to any ground pad. Connect the free The circuit (Fig. 1) is a basic diode on one side. You can determine, and ends of these two leads to the connec- switcher that has been around for many mark, the polarity of the two contacts. tors of a physically small, normally years. When the power supply is deliv- If you are into hardware experimen- open pushbutton switch (makes no dif- ering a voltage higher than that of the tation, get a couple of these special bat- ference which lead goes where). Mount battery, silicon diode Dl is forward -bi- teries and use low -value (high wattage) the pushbutton switch as desired on the ased (acts like a closed switch), while resistors as a load while monitoring plastic enclosure and mark it RESET. silicon diode D2 is reverse -biased (acts voltage across it. You will be surprised Now, when the screen goes blank at any like an open switch). This effectively at the amount of power. time, depress this switch for a restart. O

Fig. 1. At left is a circuit using a WALL SOCKET POWER SUPPLY Polaroid battery to power your computer.

r TO Fig. 2. Below is a circuit for adding COMPUTER DI a reset button for starting over. POWER POWER 1N400 CONNECTOR +5V ON

R15 D2 220K IN4001 26 IC3 Z80

RESET POLAROID CµF BATTERY GND L J JL zx81/T1000j

22 Computers & Electronics

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www.americanradiohistory.comAmericanRadioHistory.Com COMPUTER SOURCES

power generating equipment, careless 124K bytes and is optimized as a dedi- Hardware handling, or deliberate vandalism via cated controller. Connecting a CRT ter- permanent magnets. $9.50 for 51/4 " size, minal allows immediate BASIC or ma- and $14.50 for the 8" version. Address: chine- language programming. Pro- IBM Autodialer Modem. The PC2 1 2A Ad -Vance Magnetics, Inc., 625 Monroe grams can be transferred to 2732 is a Bell- compatible 212A modem that St., Rochester, NY 46975 (219 -223- EPROMs for autostart applications. fits into any slot in the IBM -PC. It can 3158). $199. Address: The Micromint, Inc., store up to 10 telephone numbers, oper- 561 Willow Ave., Cedarhurst, NY ates to 300 bps asynchronously in low Apple EPROM Programmer. The 11516(516- 374 -6793). speed, and 1200 bps synchronously in Model 2300 EPROM Programmer for high speed. It also features an RS232C the Apple II can handle TI 2516 and VIC Tape Interface. The Vik- Dubber asynchronous serial port with an inter- 2532; Intel 2716, 2732, 2732A, 2764, cassette interface allows VIC -20/64 us- nal microprocessor allowing control, 27128, and 2816; and SEEQ 5213 and ers to save and load data using a stan- operation, and optioning of the modem 5213H. The modes of operation include dard cassette tape recorder. It also al- from the IBM -PC keyboard. A "Help" EPROM to disk file, EPROM to memo- lows connecting two cassette recorders list of commands is provided, and the ry buffer, read /print contents of at the same time to make backups. An modem features auto /manual dial, auto EPROM, verify erasure of EPROM, dial next number if first number is busy, load and program disk file into instant re -dial once or until answered, EPROM, program memory buffer con- and single keystroke dialing of last num- tents into EPROM, read/print memory VIK ber dialed even if it was not one of the 10 buffer contents, modify contents of DUBBER stored. Battery protection is provided. memory buffer from keyboard, and pro- $495. Address: Rixon Inc., 2120 Indus- gram EPROM addresses directly from trial Pkwy., Silver Spring, MD 20904 keyboard. $429. Address: Software Spe- (301- 622- 2121). cialties Inc., 305 Larchway Dr., Spring- board, OH 45066 (513- 748 -0471). TRS -80 Multi- Function Board. The CMJ-IF is a multifunction subsystem Hard Disk for TI 99/4. The WDS /100 for the TRS -80 Color Computer and the Disk and Controller System allows up TDP -100 Personal Computer, that to 10M bytes hard disk to connect to the WSW' e ,". . plugs into the cartridge port and pro- TI Peripheral Expansion System in a TI vides speech synthesis accessed from 99/4A or 99/4 computer. The Unix -like BASIC, two parallel ports allowing the Directory Management System is resi- use of a parallel printer, two counter/ dent on both the utility diskette and the indicator is provided to help adjust the Personality Card ROM. The WD /100- cassette controls for proper operation. 5 stores 5M bytes while the WD- 100 -10 Power comes from the computer so no stores 10M bytes. Cost is $2599 and batteries are required. $34.95. Address: $2999 respectively. There is a clock op- Bytesize Micro Technology, PO Box tion available for $50. Address: Myarc, 21123, Seattle, WA 98111 (206 -236- Inc., PO Box 140, Basking Ridge, NJ 2983). 07920 (210-766-1700). Apple Remote Control. The PC -1 IBM Winchester. The Interface Series plugs into any I/O slot on an Apple II of Winchester drives for the IBM -PC is or II + and provides control of up to available with 5.3M bytes ($1695), 256 Leviton /BSR remote control de- 10.6M bytes ($1995), and 15.9M bytes vices via the normal household power ($2295) of formatted storage. Each sys- line. The device both sends and receives timers for use as a real -time clock, a se- tem includes all pertinent hardware and digital commands at the line carrier fre- rial communications port for serial software (JEL) for 1.1 DOS. There are quency of 121 kHz. Included on the printers or modems, and an extender 345 tracks /inch. Track -to -track access board is a bidirectional carrier inter- port that enables the user to access a time is 2 ms, and average access time is face, a CMOS real -time clock with bat- disk controller or I;tOMpack. 4K or 8K 85 ms. Other features include a 512 -byte tery backup of two months life and full bytes of EPROM /ROM space is also full sector buffer, a 32-bit ECC, and recharge capability, and switch - provided. Under $200. Address: Mag- automatic interleaving capabilities. Op- selectable interrupts of one hour, one num Distributing Inc., 1000 S. Dixie eration is also provided on 220/240 minute, one second, and 1024 Hz. Dem- HY #3, Pompano Beach, FL 33060 volts at 50 Hz. Address: Interface Inc., onstration software is provided on disk. (305- 785 -2002). 7630 Alabama Ave., Canoga Park, CA On -board firmware (2K of ROM) holds 91304 (213-341-7914). all system software, no additional mem- Floppy Protection. The Infoguard is a ory is required. $265. Address: Bi- magnetically shielded floppy -disk en- System Controller. This 4" by 41fí" Comm Systems, Inc., 10 Yorkton In- closure that protects the diskette controller on a board features a Z8671 dustrial Court, St. Paul, MN 55117 against X -rays or magnetic damage dur- that contains a Tiny -BASIC interpret- (612- 481 -0775). ing shipping. These include accidental er, up to 6K bytes of RAM and exposure to magnetic environments due EPROM, an RS232 serial interface with TTL Pinouts. The MicroChart # 6 cov- to lightning storms, passing nearby ra- selectable baud rates, and two parallel ers pinouts for virtually all 54/7400 diating electric/electronic equipment, ports. The system is expandable to TTL ICs on its two -sided, two -color,

Computers & Electronics

www.americanradiohistory.comAmericanRadioHistory.Com The Safe Video Head ------full -page plastic sheet. The data covers [dfper the part number, family type, description, and pin out. The data is reduced Cleaner from some 500 pages of data books. $5.95. Address: Micro Logic Corp., PO Box 174, 100 2nd St., Hackensack, NJ is Dry. 07602 (201-342-6518). Yes, dry! Sinclair /Timex Analog Interface. The high-speed analog interface board The Discwasher® Video Head Cleaner The graph below represents approxi- features eight channels of A/D and is the only truly nonabrasive dry head mate hardness ratings of individual eight channels of D/A for the Sin- cleaner on the market today. VCR components and various tapes clair /Timex machines. The board plugs Its superior cleaning action is the and cleaners using the Temper scale, into the rear expansion connector, and result of its textured fabric matrix, not developed by industry to measure on -board jumpers and switches permit the result of abrasive properties (like materials. A diamond, one of the hard- maximum versatility. Sequential A/D those often utilized in aluminum oxide est materials known, rates T-10. Abrams conversions can occur at 200K samples cleaners). This exclusive matrix safely Tape O y Gleam g Record/ 10 Oxides 7.9 5 per second. The electrical specifications cleans not only the video heads, but Playback T9 Head include 1.6 -µs A /D. conversion time the audio and sync heads as well. with 100 -ns sample- and -hold window; The Discwasher Video Head Cleaner is 1 -µs D/A settling time with 0.13 V /µs less abrasive than both the video head Dnowasber slew rate; 2.5- or 5 -volt full -scale option; and video drum. In fact, it's even less and eight bits resolution and accuracy. abrasive than vídeo tapes themselves. $195 with manual. Box and cable is $15. And best ofall...itworks. Easily, safely, Address: Computer Continuum, 301 and quickly. 16th Ave., San Francisco, CA 94118 lì' (415- 752 -6294). discwasher IBM Telecommunications. The 1407 N. PROVIDENCE RD., P.O. BOX 6021, DEPT. CE. COLUMBIA. MO 65205 USA A DIVISION OFJENSEN an ESMARK Company PConnection is a plug -in for the IBM - PC that contains a direct -connect Circle No. 66 on Free information Card modem, a real -time clock, and an addi- FOR ORDERIIYC:-CALL TOLL FREE (800) 221-8180 N New YORK (212) 7328600 tional serial I/O port. The modem is INFORMATION OR Bell 103/113 compatible and provides r autodial (Touch Tone or pulse dialing), TINS MOTH11010111111HIS SUPER and autoanswer in both answer and originate modes. The asynchronous SPECIALS! 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FM Sterol *9995 `SEND 240 J Circle No. 23 on Free Information Card www.americanradiohistory.comAmericanRadioHistory.Com ...COMPUTER SOURCES

10 preset numbers at the touch of a key. Features include full support for make a recommendation on the size of It fully supports most major brands of autodial and autoanswer modems, si- the bet. The player can play against one modems. Spooled printer output allows multaneous exchange of files and mes- to six decks. Requires a TRS -80 Model I even slow printers to stay on line with sages between PCs while printing and or III, 32/48K disk system. $21.95. Ad- the MicroTerm system. $70 for any ver- editing locally, split screen communica- dress: Manhattan Software, PO Box sion. Address: Micro -Systems Software tion between PCs, directory of frequent- 1063, Woodland Hills, CA 91365 (Tel: Inc., 4301 -18 Oak Circle, Boca Raton, ly used services, support for APL with a 213 -453- 6943). FL 33431 (800- 327 -8724). substitution character set, 3270 emula- tion on VM /370, full screen editor, and Commodore 64 Programs. DIARY Circuit Analysis Program. ACNAP an unattended mode for sending and re- 64 keeps track of phone numbers, birth- is an ac circuit analysis program avail- ceiving files without an operator. $149. days, appointments, etc., and files by able for 8" or 5'/4" CP /M machines, or Address: VM Personal Computing, 60 dates or page number. $59.95. CHECK- TRS -80 Model I /III with TRSDOS. It E. 42nd St., NY, NY 10165 (Tel: 212- BOOK MANAGER has a capacity of is designed to analyze circuits consist- 697- 4747). 250 checks, 100 deposits, and 50 ac- ing of resistors, capacitors, inductors, a count charges. It has built -in password voltage source, and controlled current Casino Blackjack. Casino Blackjack security. $39.95 for disk, $34.95 for cas- sources. It can calculate a 5 -node circuit Counter /Tutor for the TRS -80 Models sette version. 64 MAILING LIST holds in 0.8 seconds. It also works with com- I and III teaches play strategy as well as 250 names and addresses per file and ponent tolerances to provide worst -case point counting. The program will sug- features full screen editing, and sort. and Monte Carlo analysis. It calculates gest the best possible play for any hand. $34.95 for disk, $29.95 for cassette. VA- the minimum, maximum, mean, and Five hands are shown with the comput- NILLA PLOT features 19 editing com- three sigma points of a circuit's gain and er playing the first two hands, the player mands for Turtle Graphics to change di- phase response to any frequency input the middle hand, and the computer the rections and draw lines of any length. including linear or logarithmic frequen- last two hands. All cards are played face The Turtle has a pallette of 16 colors. cy sweeps. It can also calculate the cir- up to facilitate point counting. Three Sound is also available. $29.95 for disk cuit's noise -equivalent bandwidth. Oth- dealing speeds are provided, and with or cassette. Address: Computer Market- er design utilities are also provided. each bet opportunity, the program will ing Svcs., 300 W. Marlton Pike, Cherry $39.95. Address: BV Engineering, PO show the correct count is requested and Hill, NJ 08002 (Tel: 609 -795- 9480). O Box 3351, Riverside, CA 92519 (Tel: 714- 781 -0252). Logic Design. Micro -Logic enables en- user -programmable as to delay, truth Language Teacher. Using the Hang- gineers to draw logic diagrams directly table, and input /output clocking. The man format, and designed for the TRS - on a CRT screen. The net list required system also handles macros of up to 16 80 Model I, III, and 4 computers, these for simulation is automatically generat- pins enabling direct modelling of 16 -pin programs are available in Spanish, ed from the diagram, or may be directly MSI functions. Currently available for French, and Latin. Other programs typed in. A timing -level simulation can IBM -PC with Apple II coming soon. cover literature, word power, and Ger- be performed to evaluate design before $450. Address: Spectrum Software, 690 man and Russian practice. $29.95 per building hardware. The system will W. Fremont Ave., Suite 11, Sunnyvale, program. Address: George Earl, 1302 handle 500 to 2000 gates with all gates CA 94087 (Tel: 408 -738 -4387). South General McMullen, San Anto- nio, TX 78237.

Numismatics. The Coin Collector for the Apple II series consists of six programs in which collection information can be entered, deleted, changed, searched, sorted, and printed. It catalogs foreign or domestic lists by denomi- nation, country, description, year, value, or source. A Meeting List allows sorting and selecting meetings by date and location, a Source List gives sources for coins, supplies, and information on trades and liquidations. The File Trans- fer utility allows transferring data to other computer via phone links. $49. Address: Andent, Inc., 1000 North Ave., Waukegan, IL 60085 (Tel: 312- 223- 5077).

IBM -PC Communications. RELAY enables one IBM PC to link to another, act as a TTY, an APL terminal, or a 3270 device. It provides full error detection and correction while transferring data in both directions at the same time.

26 Computers & Electronics

www.americanradiohistory.comAmericanRadioHistory.Com No wonder they call it the SUPERFONE! At Last -a Cordless Phone with TWICE the Range, Sound Fidelity to Rival Phones with Cords, and a Privacy Code System-All This in a Phone Less Than an Inch Thick!

The Super Fone is less than I" thick. The hase unit has a built -in speaker phone, a fully independent intercom and is 110 volt -220 volt switchable.

Until now, cordless phones have First, the base station is a speaker given you wonderful convenience. But phone. Touch a button and you can have Rotary Phone or Touch Tone R ? they've had two problems: a hands -free conference conversation in SUPERFONE 1. The range is limited to 600 to 700 the room in which the base station sits. feet. Next, it's an intercom. You can page Is Available For Either! 2. Some of them sound as though the handset from the base unit and have a Most cordless phones work on "pulse" you're talking inside a barrel. private conversation. You have a true (rotary) only. You can't use them for MCI, As cordless phones have become wireless intercom, not just a signal. Sprint, or any of the other systems requiring enormously popular, another problem Third, you have a privacy button. TouchTone - including talking to a computer. has arisen: two people, living near each Push that button and you'll still be able to The SuperFone 650 now has a Touch other, can have the same channel. Not hear anything the other party says, but he Tone model, so you can have the unmatched only is there line confusion, but someone or she won't be able to hear you until you double convenience of a cordless phone and else can literally make a long distance call take the button off "hold." tone dialer! on your phone. Fourth, you have an automatic redial. (Touch Tone model slightly higher.) No more. Never again. Touch the key and the SuperFone will redial the last complete number. Range: 1500 Feet OR MORE! What else? A security switch which makes it impossible for anyone to call out The SuperFone 650 uses state -of- without changing the -art electronics to bring you the on the remote phone, TRIPLE THE RANGE the ability to receive calls. A volume Sound quality is ultimate cordless phone. control for the speaker on the base unit. A OF ANY CORDLESS PHONE! it superb, 1500 feet or superb - and stays to page the base from the station. That's more call button The SuperAntenna will give your more from the base cordless phone. THIS PHONE HAS than twice the distance of standard cordless phone, regardless of make or cordless phones. EVERYTHING! model, three times the range it has now. Only SuperFone 650 has a secret 30- Second Installation If the range is 700 feet, it'll leap to over 2,000. If it's 1500 feet, it could be as code system to prevent interference and Plug SuperFone 650 into any your far as one mile! false operation of the phone. You choose wall AC outlet. Push its standard modular from 512 possible "code" combinations. Easy to install. Only $79.95 terminal into the telephone plug. You're in complete. Add $4.50 for shipping. Both the base unit and the phone are business. locked onto that code, which you can Every component is heavy -duty, change when you want to. from the built -in condenser microphone No other phone can interfere. No (with automatic gain control) to the LED other unit can share the signal. No one indicator lights. This phone is designed for else can hear or speak on your carrier - hard use. wave. The SuperFone 650 is yours for Enormous Range $249.95 in regular pulse -dial version, in Touch Tone *. If you want the We say the SuperFone 650 has a $269.95 SuperAntenna with it, giving you a range range of 1500 feet. of a mile or even more you can have Notice we didn't say "up to" or "as far - - both for $319.95 (rotary pulse) or as" 1500 feet. There's no hedging, you can get the the $339.95 (Touch Tone). Or because this seems to be minimum, alone for $79.95. not the maximum range. SuperAntenna Users report 1800 and 2000 feet. That's nearly half a mile. SuperFone 650 is We Absolutely Guarantee! a radiophone, not a toy, and that's why its Use the SuperFone 650 (or any signal doesn't break up or start hissing or electronic instrument you acquire from For instant service, if you have a VISA crackling when you get half a block away. us) for up to 30 days. If for any reason you or MasterCard, call toll -free 24 hours You can tell when you heft it. It's a decide not to keep it, return it for a 100% a day, seven days a week: Little Giant. You can feel the power inside. refund. What a marvel of electronic engineering it The SuperFone 650, 1- is! And its tough, too. It fits into your shirt 800 -824-7888 rotary pulse dial - $249.95 Ask for Operator 551. pocket, and you can bounce it around all phone and SuperAntenna - $319.95. (in California: 1- 800-852 -7777) day without damaging it. The SuperFone 650, Touch Tone dial - $269.95 Speakerphone, Intercom phone and SuperAntenna - $339.95. Everything! - The SuperAntenna, no phone included $79.95. is The Everything - NEW HORIZONS SuperFone 650 Multi -Line Adapter, lets you plug several Phone. Anything any phone can do, it can 100 lines into one SuperFone - $39.95. Dept. CE8, 1 Penn Plaza. Suite do. Add $4.50 per total order for shipping. New York, NY 10119 Circle No. 17 on Free Information Card

www.americanradiohistory.comAmericanRadioHistory.Com For everyone who's tried to top the MX -80, bad news. We just did. Epson.

Computers & Electronics 28

www.americanradiohistory.comAmericanRadioHistory.Com The Epson MX -80 is the best - selling dot selectable. And can be mixed in the same matrix impact printer in the world. It has print line. Everything from 72 DPI (dots - been since its introduction. And despite the per -inch) Plotter Graphics to the 640 dots host of imitators it spawned, no one has per line resolution designed to match the been able to top it. Until now. remarkable monitor clarity of the Epson FX -80: Son of a legend. QX -10 personal computer. The new Epson FX -80 is far more than just And that is in addition to an astonishing doo -dads added on to last year's model. It's array of 136 different user - selectable type the most astonishing collection of features styles including Proportional, Elite and Italic ever assembled in a personal printer. as well as the more conventional faces you For starters, it's fast: 160 CPS. And clean. get on other printers. All the print quality Epson is famous for in a Hard -to -beat hardware. tack -sharp 9x9 matrix. The FX -80 has all the hardware features But that hardly scratches the surface. you've come to know and love on the MX Create your own alphabet. Series: logic seeking, bidirectional printing, With the new FX -80, you aren't limited to the by- now -famous disposable printhead, ASCII characters. You can create your own. and more. Any character or symbol that can be defined The FX -80 features an adjustable pin in a 9x11 matrix can be added to the FX -80's platen or optional friction /tractor feed, so already impressive library of type styles and you can use fanfold, roll or sheet paper ... stored in its integral 2K RAM. backwards or forwards. The FX -80 even So you can create "Sally's Gothic" or gives you reverse paper feed. "Tom's Roman" just by downloading and And if you're printing forms, the FX -80 modifying standard characters. Or you can has a feature you're gonna love: a function create a custom set from scratch. Either way, that allows you to tear off the paper within you can store up to 256 new characters. And one inch of the last print position. if you don't need a new alphabet, the RAM Be the first on your block. functions as a 2K data input buffer. We'd be willing to bet that the FX -80 - like Who knows graphics better than Epson? the MX -80 - will have its share of imitators. Nobody, that's who. And if you don't Don't be fooled. To make sure you get the believe it, witness the FX -80. genuine article, rush down to your local With a 12K ROM capacity, the FX -80 gives computer store right now and let them show you a few things the others don't. For exam- you everything the FX -80 can do. ple, not one, not two, but seven different dot And while you're there ... ask them to addressable graphic modes are program show you how it works with our computers.

EPSON The New EPSON AMERICA, INC. Epson FX -80. COMPUTER PRODUCTS DIVISION See it at your dealer now. 3415 Kashiwa Street Torrance, California 90505 (213) 539-9140. Outside California, phone (800) 421 -5426 for the Epson dealer nearest you.

Circle No. 25 on Free Information Card

August 1983 29

www.americanradiohistory.comAmericanRadioHistory.Com I www.americanradiohistory.comAmericanRadioHistory.Com &Tot FOR NE4 PERSONALCOMPUTERS Intel's 68 -pin iAPX -188 ccmbines an enhanced 8088 16 -bit CPU and up to 20 support ICs in a single package for double the performance and much lower device and assembly costs By Tony Zingale

MICROPROCESSORS represent a great enhanced 8088 microprocessor, the advance in electronics owing to their same one used in the IBM -PC and simi- small size, programmability, and low lar machines. Although the two chips cost. Developing them is as much an art are object -code compatible, 10 more in- as it is a science since considerations ex- structions have been added. The logic tend beyond performance and reliabil- within the iAPX 188 is shown in Fig. 1. ity. Production cost, peripheral avail- Physically, the iAPX 188 is not com- ability and cost, and software availabil- patible with the 8088 since its JEDEC ity are important factors, too. The sum Type A, 68-pin, leadless package has 17 can determine the success of the CPU in pins on each of its four sides, as shown the marketplace -how many comput- in Fig. 2. It does directly address 1 ers will be designed around it. megabyte of memory, is compatible Since the introduction of the micro- with 8282/83/86/87, 8288 and 8289 processor in the mid -1970s with Intel bus support components, and requires a Corporation's 16 -pin 4004 CPU, lead- single 5 -volt power supply. ing to the 40 -pin bug -like package of the Since the data path is only 8 bits wide, 8080 CPU and others, there has been a there is a saving in parts, and a reduc- swift evolution in the design of these tion of board space of about 1/S can be "computers on a chip." Zilog, for exam- realized over a 16 -bit approach. Direct ple, quickly followed with its Z80 CPU, peripheral interfacing is also easier which is much like an 8080 that com- since most reasonably priced periph- bines a clock generator and a systems erals handle data 8 -bits at a time. With controller into one IC instead of having an 8 -bit system requiring eight 64K -bit three separate devices. Other micro- memory chips for each 64K -byte block, processor makers followed suit with this is cheaper than going to 16 -bit wide their designs, each playing "can you top memory. Since the iAPX 188 (80188 is this" with new products. This lead to the part number) combines high- perfor- the development of 16 -bit CPUs - mance 16 -bit internal architecture with Zilog's Z -8000, Motorola's 68000, and an 8 -bit bus interface, this allows 20- Intel's 8088, among them. Their larger megabyte addressing and 64K -bytes of word size makes them more powerful I/O addressability, which is becoming a than the 8 -bit CPUs. "standard" in modem microcomputers. The beat goes on with the announce- In performance, the 80188 can provide ment of a next -generation CPU in up to 65% to 95% of the performance of Intel's advanced processor family -the its 16 -bit relatives while retaining the in- iAPX 188. It shows great promise in be- terface advantages of the 8 -bit data bus. coming a very popular nucleus for per- Besides the CPU, several functions sonal and small- business computers for have been integrated on the 80188. One a host of reasons. With a square shape of these is the clock generator that pro- and 68 -pin package, it's apparent that vides an 8 -MHz system clock. Other this is a different type of CPU than the functions include two 16 -bit program- ordinary one. Actually, the single chip mable timer/counters for implementing incorporates a number of ICs, combin- baud -rate generation, real -time clocks, ing up to 20 equivalent chips that con- and delay counters, with a third counter stitute essential microprocessor build- (not externally connected) used to im- ing blocks that are ordinarily separate plement time delays and which can be support chips. used as a prescaler. The CPU partition itself is really an Also included are two high -speed, in-

www.americanradiohistory.comAmericanRadioHistory.Com SUPER CHIP

TMR OUT 1 TMR OUT 0 TMR IN TMR IN CLKOUT V GND 1

INT3 IN -A1 PROGRAMMABLE NMI INT2 INTAO TIMERS INT1 INTO EXECUTION UNIT 0 1 2 MAX COUNT REGISTER B 16 -BIT MAX COUNT ALU REGISTER A 16-BIT ONTROL REGISTER GENERAL 16-BIT PURPOSE COUNT REGISTER REGISTERS ORQ1

INTERNAL BUS P OGRAMMABLE DMA UNIT

0 1 CHIP- SELECT 20 -BIT SOURCE POINTERS BUS INTERFACE 16 -BIT UNIT SO -S2 20 -BIT DESTINATION SRDY UNIT SEGMENT POINTERS REGISTERS ARDY 16 -BIT TEST PROGRAMMABLE TRANSFER COUNT HOLD 4 -BYTE CONTROL CONTROL HLDA PREFETCH REGISTERS REGISTERS

QUEUE NNW RESET / I I 1..Fil5 ALE PCS5 Al U L i DEN ADO- A16 S3- P=1-4 LOCK AD7 A19 S6 DT R A8-A15

Fig. 1. Block diagram of the various parts of the iAPX 188.

dependently programmable DMA BOTTOM channels to provide data transfers between system memory and I/O devices. I DMA transfers can occur between ZZ memory and I/O or within the same Q O } O M Y_ (7 cr) u) C." space (M -M, or I /O -I /O). Each DMA °óQ ,_ U U U ==cn Fw Z Z~ Z j Z opw 2 î channel maintains two 20 -bit source and destination pointers that can be in- _ cremented, decremented, or left un- so changed after each transfer. Data trans- ///UCS fers occur a byte at a time, and can be anywhere within the 1- megabyte ad- PCS6 A2 ARDY dressable memory space. This allows a PCS5 Al CLKOUT \ PCS4 maximum transfer rate of 1 Mb /s. The RESET ¡ r ' user can specify several different modes =I ! PCS3 X2 \ PCS2 of operation via the on -chip DMA X1 PCSI channel control word. VSS Vss A multi -level programmable inter- ALE OSO PCSo rupt controller that can resolve priority RD OSMD RES among up to five external interrupts WR OS1 TMR OUT 1 plus interrupts from the five internal S7 TMR OUT 0 sources (timer, DMA, etc.) is also pro- A19 S6 TMR IN 1 vided in the chip. Each interrupt has a A18 SS TMR IN 0 programmable priority level and a pre- A17 S4/í DRQ1 assigned interrupt vector type used to A16 S3 DRQO derive an address to a table in memory where the interrupt service routines are

,,s2 ó O Q M ó N ó ^ ó Q1 ^ CO O stored. This enhancement makes the 0 Q Q O QaâaaaâaQaQa Q a iAPX 188 interrupt response time about 50% faster than the 8088. Multiple PIN NO 1 MARK Fig. 2. The 68 -pin, leadless package has 17 pins on each side.

Computers & Electronics 32

www.americanradiohistory.comAmericanRadioHistory.Com TIMER REQUEST ADDER CONTROL 20 BF ADDER; SUBTRACTOR LC G IC

20 DRQ1 1

TRANSFER CH.j 1 COUNTER 8259A's can be cascaded to provide up aEQUEST to 128 external interrupts. SELECTION Integrated programmable memory DEST. ADRS. POINTER CH. 1 LOGIC and peripheral chip-selects, plus a programmable ready generator, replace DMA DRQO SRC. ADRS. POINTER CH. 1 many of the conventional TTL devices CONTROL required to interface system memory LOGIC and I/O devices to the CPU. The wait- TRANSFER COUNTER CH. 0 state generator is necessary so that the CPU can interface to memory and I/O INTERRUPT DEST ADRS. POINTER CH. O REQUEST devices of varying speeds. The result of the integrated logic eliminates external propagation delays, thus speeding up SRC. ADRS. POINTER CH. 0 the data flow. Three memory ranges (lower, middle, upper) can be programmed to variable lengths (1K, 2K, CHANNEL CON -RDL WORD 4K, ... 256K) so that a variety of memory chip sizes can be used. Also, any- CHANNEL CON -ROL WDRD O where from zero to three wait states can be programmed so either high -speed or low -cost and slower memories can be INTERNAL ADCRESS /DATA BUS used. The added functionality of the 80188 (i.e., timers, DMA, interrupt controller, chip selects), uses on -chip 16 -bit registers for each integrated device contained in a 256 -byte control block. This logic is shown in Fig. 3. The control register block may be I/O or memory mapped based on initialization for a new control block pointer in the CPU. Except for these additions, the register architecture of the 80188 is identical to the 8086/8088. A local bus controller provides the required address, data, and control signals to the local system bus. The pipe - lined architecture of the 80188 allows savings in memory cost since instructions are prefetched into a 4-byte execution queue, high performance can be maintained while using slower (thus less expensive) memory. Other cost savings come from the use of an 8 -bit rather TIMER TIMER TIMER 2 DMA DMA INTO INT' IHT2 INTS NMI than ad6 -bit external data bus. A typical 0 1 2 0 o iAPX 188 computer is shown in Fig. 4. Q( Since the iAPX 188 is software compatible with the 8086 and 8088 CPU's, compilers, operating systems, and ap- TIMER INTERRUPT plication CONTROL REG. REQUEST REG. programs written for the IMP 'VP 8086/8088 will run on systems using the DMA 0 INTERRUPT new CPU. Current operating systems CONTROL REG. MASK REG. include Intel's iRMX 86/88; Digital Research's CP -86, and CP DMA 1 IN- SERVICE /M /NET; CONTROL REG. REG. and Microsoft's MS -DOS and Xenix (a INTERRJPT All EXT. INPUT 0 PRIOR. LEV. Unix implementation). popular pro- PRI DIRT.' Mr-

CONTROL REG. . MASK REG. gramming languages are available, in- RESOLVER cluding BASIC, Fortran, Pascal, Cobol, EXT. INPUT 1 INTERRUPT CONTROL REG. STATUS REG.

EXT INPUT 2 Fig. 3. Block diagrams of the CONTROL REG. DMA control logic (top), three timer VECTOR circuits (center), and EXT. INPUT 3 INTERRUPT GENERA- interrupt controller (bottom). CONTROL REG. REQUEST TO TION On-chip 16 -bit registers are used PROCESSOR LOGIC for each integrated device.

August1983 INTERNAL ADDRESS/DATA BUS

www.americanradiohistory.comAmericanRadioHistory.Com -- 111Sunclex - f08 PAYING BILLS... SUPER CHIP This could be the last check you .Iwab. 16 MHz Di-

Xl X2 UCS 8282 OR 8283 V.,. ADO -AD7 LATCH A8 -A15 STB OE ALE STB OE RESET RES

80183 Because it lets you try Sundex's RD IF Personal PayoblesTM program, WR PROGRAM designed to take over tedious bill RAM paying chores. MCSO -3 SRDY

Personal Payables:M ARDY 11 LOW writes checks - standard or NMI RAM continuous form HOLD alerts you to payments coming LCS due TMR IN 0 sms. stores amounts payable for TMR OUT 0 regular payments 8286 OR I'lm CLOCK 8287 DO-D7 keeps continuous, accurate RANSCEIVEe balance T (E :+ SERIAL DT -R. Ii0 handles up to 10 checking DEN accounts PCSO T And Taken the Fear Out of Al We've A2 Trying ... our easy -English manual INTO and on- screen instructions make it easy for anyone in the family to DISK do it. INTt INTERFACE Start now to write off writing checks! FCS4 HARDWARE DRQO To Try It -send $19.95 for full use of program (limited to writing 8 checks). When you're ready to buy it, call us toll free for Fig. 4. Block diagram of a typical way in which the access code and we'll bill you the 80188 (iAPX 188) could be used in a computer. for the balance ($80.00). To Buy It NOW -send $99.95 and never PL /M, and C. And applications pro- Interface Unit (BIU) of the CPU. Addi- write another check grams that can run on computers based tionally, the 80188 executes many in- on the iAPX 188 already abound. structions in fewer clocks than the 7 Yes, I want to take advantage As previously mentioned, new in- 8086/8088. of your TRIAL OFFER- $19.95 struction types have been implemented The use of the 8087 Numeric Proces- I'm convinced, send me your on the new CPU. These include a block sor Extension allows operations such as Personal Payables TM move, push or pop all registers, arithmetic, trigonometric, exponential, Program- $99.95 rotate /shift immediate, and multiply and logarithmic instructions to show an Specify: IBM 128K IBM 64K immediate. These new instructions not increase in speed of some two orders of COMPAQ Osborne only increase the raw computing speed magnitude. Other chips, such as the Apple II TI Professional of the CPU, but they also apply to high - 82720 GDC, 82730 Text Coprocessor, Apple Ile level languages and multitasking and the 82586 Ethernet Controller are Payment: Check VISA CMasterCard implementations. also compatible with the iAPX 188. Colo. residents odd 3% soles tax The iAPX 188 delivers about twice In sum, the iAPX 188 represents an- the performance of the 5 -MHz 8086/ other evolutionary step forward in Cord x Exp. Dots 8088. This is attributed to some hard- microprocessors. Its performance is S{gnoturs ware enhancements. For instance, effec- said to double that of its 8088 cousin, Moms tive address (EA) calculation typically while cost is half as much. Moreover, Address involving the addition of a segment reg- software compatibility with the 8088 is in- maintained. You can expect to see com- City Stots Zip ister plus a displacement and some is per- puters incorporating this chip in the Moll to: Sundex Software Corp. dex value to a given segment Dept CE082 formed by an on -chip microcode very near future. The next move is up to liSundex 3000 Pearl St. sequence in the 8086/8088. In the competitive processor makers, who will Boulder, CO 80301 80188, this calculation is performed by likely follow with their new -generation Phone orders: 1- 800-835 -3243 a dedicated hardware adder in the Bus CPUs. In Colorado call: 1- 303 -440 -3600 Circle No. 37 on Free Information Card Computers & Electronics

www.americanradiohistory.comAmericanRadioHistory.Com Commodore - 64 Word Processors

SCRIPT 64 EXECUTIVE WORD PROCESSOR

Rated best by COMMODORE. This is the finest word processor available. Features include lino and paragraph insertion /deletion, indenta- tion, right and left justification, titles, page numbering, characters per inch, etc. All features acre easy to use and understand. With tabs, etc. SCRIPT -64 even includes a dictionary/spelling checker to make sure your spelling is correct. The dictionary is user customizable to any technical words you may use. Furthermore, all paragraphs can be printed in any order so doctors, lawyers, real estate agents, and homeowners will find contract writing and everyday letters a snap. To top things off, there is a 100 page manual and help screens to make learning how to use SCRIPT -64 a snap. This word processor is so complete we can't think of anything it doesn't have. When combined with the complete database you have a powerful mailmerge and label program that lets you customize any mailing list with per. sonalized letters. List $99.95. Sale $79.00. (plus postage) Disk Only. COMPLETE DATA BASE

This is a user friendly database that makes any information easy to store and retrieve. The user defines the fields and then can add change, delete and search for any category he wants. When combined with the SCRIPT -64 Executive Word Processor you can search out any category (zip codes, hair color, etc.) and print super personalized letters. List $89.00. Sale $69.00. (plus postage) Disk Only.

TOTAL WORD PROCESSOR PLUS 5.2

This top quality word processor was specially designed for PROTECTO ENTERPRIZES. Features include line and paragraph insert and delete, right and left justification, multiple copies, and line spacing. Extra functions include mailmerge, embedded footnotes, extra user defined character sets, plus a complete label program. List $69.90. Sale $56.00. (plus postage) Disk add $7.00.

QUICK BROWN FOX WORD PROCESSOR

(Cartridge). Nationally advertised all purpose word processor that uses menu control to Ist you manipulate your text. Includes the features most often asked for including right and left justification, wordwrap, and more. List $69.00. Sale $59.00. (plus postage).

LOWEST PRICES 15 DAY FREE TRIAL 90 DAY FREE REPLACEMENT WARRANTY i BEST SERVICE IN U.S.A. ONE DAY EXPRESS MAIL OVER 500 PROGRAMS FREE CATALOGS i

WE SHIP C.O.D. HONOR VISA AND MASTER CHARGE ADD $3.00 SHIPPING FOR C.O.D. ADD $2.00 MORE PROTECTO SPECIAL SERVICES: ENTEFtPRIZES(VVE LOVE OUR CUSTOMERS) One Day - Express Mail add $10.00 BOX 550, BARRINGTON, ILLINOIS 60010 Phone 312/382.5244 to order

Circle No. 40 on Free Information Card

www.americanradiohistory.comAmericanRadioHistory.Com Learning electronics is no picnic.

At any level it takes work and a few sacrifices. But with CIE, it's worth it.

www.americanradiohistory.comAmericanRadioHistory.Com Whoever said, "The best things in life facts about circuits and transistors. answer your question in terms you can are free;' was writing a song, not living Electronics is interesting! It is based understand. a life. Life is not just a bowl of cherries, on recent developments in the industry. CIE prepares you for your FCC and we all know it. It's built on ideas. So, look for a License. You fight for what you get. You get program that starts with ideas and For some jobs in electronics, you what you fight for. If you want a builds on them. Look to CIE. must have a Federal Communications practical, working thorough, knowl- Programmed learning. Commission (FCC) License. For edge of electronics, come to CIE. That's exactly what happens with others, some employers tend to You can learn electronics at home CIE's AutoProgrammed® Lessons. consider your license a mark in your by spending just 12 hard -working Each lesson uses famous "programmed favor. Either way, your license is hours a week, two hours a day. Or, learning" methods to teach you government- certified proof of your would you rather go bowling? Your important principles. You explore knowledge and skills. It sets you apart success is up to you. them, master them completely, before from the crowd. At CIE, you earn your diploma. It you start to apply them. You More than half of CIE's courses is not handed to you simply for putting thoroughly understand each step prepare you to pass the government - in hours. But the hours you do put in before you go on to the next. You administered exam. In continuing will be on your schedule, not ours. learn at your own pace. surveys, nearly 4 out of 5 graduates You don't have to go to a classroom. 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COMPACT DISC DIGITAL AUDIO SYSTEMS How the new digital audio 4.7 -inch playback record system works By David Ranada

COMPACT Disc players -the hottest closely spaced intervals, the waveform new products to appear on the audio is said to be sampled. The waveform in scene in quite some time -are probably Fig. lA gets sampled in Fig. 1B, the the most complex and sophisticated samples being the points at the ends of electronic devices for the home ever of- the vertical lines. Mathematical models fered to the consumer. They are de- of this activity say that as long as sam- signed to play back, with extraordinari- ples are made at least twice as frequent- ly high audio fidelity, up to 75 minutes ly as the highest frequency contained in of music recorded on mirror -finish 12- the signal being sampled, no informa- centimeter (4.7 ") acrylic discs. The sys- tion is lost. From the information con- tem does not wear out or damage the tained in the samples the waveform can discs while it is playing them since only be exactly reconstructed, as long as the a light beam contacts the disc to read it waveform did not contain any frequen- out; that light comes from a semicon- cies greater than the sampling rate. The ductor laser. Compact Disc system's designers want- CD players combine aspects of a ed it to have a frequency response ex- home computer's disc drives (in the tending to 20,000 Hz, so the audio sig- player's disc -drive and laser- tracking nal for Compact Disc master tapes is servos), a specially programmed micro- sampled 44,100 times per second. The processor (to handle a player's control sampling rate is 44.1 kHz, more than functions), a digital signal processor (to twice the highest frequency desired by a decode and correct the digital -audio bit slight margin. stream), and a high -quality, high- preci- Quantization-the second basic oper- sion digital -to- analog conversion sys- ation of digital audio -is shown in Fig. tem (to change the digital audio data 1B and 1C. It is simply the measure- into normal audio signals of high sonic ment of the amplitude of the samples, quality). How do all these systems inter- the results of which are shown here in act to make a CD player work? arbitrary numerical units in both decimal and binary representation. Binary Digital Audio Basics. A digital -audio representation is used by analog -to -digi- recording/playback system converts a tal converter (ADC) circuits in digital - smoothly changing, analog waveform audio equipment. into a series of binary numbers describ- Note that the measurements are not ing the waveform, records those num- infinitely precise; there is some "round- bers as pulses on a suitable medium ing off" to the closest integer value. (magnetic tape or the master disc for Making an infinitely precise measure- Compact Disc pressings), plays back ment would generate a number with an those pulses, converts them into num- infinite number of digits (or bits); there bers, and finally reconverts the numbers has to be a practical limit imposed to the into a smoothly varying analog wave- resolution of the measurement. This form (Fig. 1). How can such a system limitation creates noise and distortion in provide the high audio quality claimed the reproduced signal, but the noise and by advocates of digital audio? After all, distortion can be reduced to any level by typical Compact Disc player specifica- increasing resolution of the ADCs. tions claim a dynamic range of more In the Compact Disc system, audio is than 90 dB, flat (±0.2 dB) frequency re- encoded with 16 bits of resolution, sponse to 20,000 Hz, distortion of less meaning that the ADCs used in Com- Radial tracking system than 0.01 %, and no wow or flutter. pact Disc mastering can distinguish of the Philips Compact The answer lies in the way the two ba- changes in voltage levels of 1 in 2' °. This Disc Audio System. sic operations of digital audio are per- translates to 1 in 65,536 or the equiva- formed. The first operation is called lent of 1" in about 1 mile. With this de- sampling. If the amplitude of a gree of resolution, the signal -to -noise waveform-any waveform -is some- ratio or dynamic range of the CD sys- how captured or frozen at regular, tem can be greater than 90 dB, the theo-

August 1983 41

www.americanradiohistory.comAmericanRadioHistory.Com ..CD DIGITAL AUDIO retical limit being a little better than 97 dB. Since quantization error is also responsible for nearly all the distortion in the digital audio process, it too is reduced to very low levels with 16 -bit A encoding. The digital numbers from the ADC are converted into a pulse train (Fig. 1D) for recording on tape or on a Com- pact Disc master. Since it has only two possible values (high and low, corre- 6 sponding to 1 and 0), this waveform is 6Vt7VT far more immune to distortion and noise 5 5V+ in the recording and playback process 4 than the original analog waveform. Dis- 4v- B 3 tortions that can and do occur in the 3V- media (tape or optical disc) 2 data -storage 2V- only rarely change the recorded pulse to confuse the decoding tvt train enough 0 circuitry as to whether a high or low ov value was intended. ( 3 5 6 6 7 6 1 1 1 1 In playback-this is where a CD 6 5 3 0 3 5 6 player comes in -the original pulse c ; 110 I 'I , I'10 +t1 11.01-311- (ott I c of I oJi ooG' cot I o01 I Ylt I tot ¡ito waveform is recovered from the record- -1- 1E). After it is con- ed waveform (Fig. D into the original numerical se- verted E quence (Fig. 1F) the series of digits is 0,1,0111,0 1110 11101tOt1ottic.otI©t 0oo1oot1oo1lOt111011110! fed into a digital -to- analog converter (DAC) which changes them into dis- F3 5 6 6 7 6 6 5 3 1 1 0 1 1 3 5 6 crete voltage levels (Fig. 1G). Because the numbers are clocked into the DAC 7v 6 at the same rate as they were generated 6V at ADC during the recording pro- the 5V cess, variations in the speed of the play- 4 back medium do not affect the repro- av T G 3 duced waveform. Therefore, wow and 3v - 2 flutter are eliminated! 2v An output- smoothing circuit re- t IV moves the inaudible ultrasonic compo- 0 nents that give the staircase waveform Ov it's disjointed character. The filtered waveform makes up the output of the digital audio system, an output that is a very high -fidelity replica of the original input signal. H

The Compact Disc and Player. Be- fore exploring some of the processing that goes on inside a Compact Disc player let's take a look at what a CD player has to play, the Compact Disc it- Fig. 1. Basic operations of digital audio: sampling (B); quatization (C); self. Audio information is recorded on a recover of data (E,F); and reconversion of data into an audio signal (GH). CD pressing in a track of microscopic "pits" on the surface of a transparent acrylic disc 12 centimeters in diameter, scanning laser beam. It comes up 3 and the ikustration on page 40. It con- as shown in an accompanying photo. through the bottom of the disc, hits the sists of an optical scanner, containing a These pits average slightly less than 1 aluminized signal surface (AL), and is semiconducter laser and a photodiode, micrometer in length; each revolution reflected out again. Changes in the in- mounted on a tracking device that al- of the track is 1.6 micrometers away tensity of reflected light are detected lows the scanner to move across the face from the next. Data is contained in the (Fig. 2B) and converted to a digital bit of the spinning disc. The disc spins length and spacing of the pits and the stream (Fig. 2C). The pits are protected counterclockwise in relation to the laser spaces ( "lands ") between them. on one side by the bulk of the disc's plas- beam and the track of pits starts toward A cross -section of a CD pressing is tic substrate (S), and on the other by a the center of the disc and moves toward shown in Fig. 2A. In it you can see that, tough lacquer coating and a label (PR). the outside edge, both movements being though the pits (P) are made as indenta- A typical mechanical arrangement of opposite to those with analog (black - tions, they appear as "bumps" to the a Compact Disc player is shown in Fig. disc) records. The speed of rotation

42 Computers & Electronics

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www.americanradiohistory.comAmericanRadioHistory.Com ...CD DIGITAL AUDIO

slows down between the start of a disc Figure 4, as complicated as it appears and its finish. at first glance, summarizes all the main PR AL - It starts out spinning at around 500 digital operations performed to a digi- rpm and ends up spinning at about 200 tal -audio signal on its way to the master s rpm if the program extends close to the Compact Disc. The digital data on a CD edge of the record. The speed is con- is gathered into units called frames and trolled by servo networks so that the the diagram depicts the encoding pro- track is always passing over the laser at cess for one frame (which takes only between 1.2 and 1.4 meters per second. about 136 microseconds to be scanned The steady decrease in rotation speed by a CD player's laser). TIME 00000'l oo'l o increases the amount of information The digital -audio signal content of a C 0001 oo I 0000, 0°000'1 oo'l 000'i that can be held on the disc. If the rota- CD frame consists of enough information rate were constant, the pits and al- tion to make up six sampling periods Fig. 2. A 1.2 -mm thick Compact Disc ternating lands near the start of the disc (Fig. 4A). Since there are 32 bits gener- (A) consists of three layers: an would be unnecessarily large. ated in one sampling period (16 bits per acrylic substrate (S), an aluminized stereo audio channel every 22.68 micro- reflecting "signal surface" (AL), and a lacquer coating and label (PR). It be a stupendous seconds) there are 32 X 6 = 192 audio - Data on Disc. would The pits (P) are pressed from above and misleading oversimplification to data bits per frame (Fig. 4B). Each 16- but the laser beam scans from below. say that digital -audio data gets recorded bit sample is broken down the middle The reflected intensity of the beam on a Compact Disc exactly as it into two 8 -bit bytes, called symbols in varies as the pits pass by (B) and these emerged from the digital -audio master CD terminology (Fig. 4C). One symbol variations hold the digital-audio data (C). recorder. There is a good deal of digital contains the 8 most significant bits of signal manipulation on the audio data the sample, the other contains the 8 before it finds itself on the signal -surface least significant bits. This repartitioning o detect and correct for any errors in of a Compact Disc. Most of this proof the data yields 24 symbols containing the data stream as read by its laser (see cessing is undone by a CD player in its only digital -audio data per frame. box on page 45). Simply put, the redun- operations to recover the original digi- The first major signal -processing op- dant data is a mathematical summary of tal- audio. Then why is all the processing eration on the audio data during the en- the digital-audio data contained in the necessary? The three main reasons are: coding process is depicted in Fig. 4D frame and is a special form of parity - to increase the playing time of a CD, to and E. These two lines depict the func- check code (for those of you familiar make it audibly immune to disc damage tions that make the data stream immune with digital data transmission). The (scratches, fingerprints, small pressing to transmission errors due to disc de- first error -correction symbols to be gen- defects), and to provide special digital fects or damage. erated are the four Q symbols which control and data signals for advanced They start with the generation of re- find their places in the middle of the Compact Disc applications. dundant data that a CD player will use frame. Next comes interleaving, a process for making the recorded signal immune to disc scratches and other relatively Disc large -scale defects (see accompanying box). Interleaving scrambles the sym- Objective lens bols from a large number of frames pre- Magnet ceding and following the one being en- Focus coil coded in the diagram. This scrambling (depicted by the arrows between Fig. Collimator lens 4D and E) is performed in a very strictly defined way, which moves originally consecutive symbols to distantly separated frames, and which moves symbols from distant frames into the one under construction. The Q -parity symbols also undergo this shuffling process. No data is left out or repeated -the number Photo detector of digital -audio symbols per frame is still 24, the number of Q -parity symbols is still 4 -its just that 28 previously consecutive symbols find themselves strewn over about 40 different frames in a very regular, and undoable pattern. Fig. 3. Cross section of a laser After interleaving, four P- parity er- scanner showing how servo ror- detection /correction symbols are signals pull on a magnet calculated from the 24 audio and 4 Q- attached to the focusing lens. parity symbols now in the frame. This (Courtesy Philips) additional parity data is tacked onto the end of the frame. The whole parity/ interleaving scheme is called CIRC (Cross -Interleave Reed -Solomon Code).

44 Computers & Electronics

www.americanradiohistory.comAmericanRadioHistory.Com To the start of the frame is added one for sing- or play -along recordings. symbol). This symbol sequence is then 8 -bit symbol containing control and dis- (Since the C &D symbols contain 8 bits fed into a digital modulation circuit play (C &D) bits. At present this symbol and occur 7,350 times per second once which converts, via a read- only-memo- is used only to hold data about the per frame -a voice signal with a signal - ry look -up table, each 8 -bit symbol into timings of each musical selection on a to -noise ratio of about 45 dB and a fre- a 14-bit word in a process called EFM Compact Disc, and data signalling quency range up to about 3,500 Hz can (Eight -to- Fourteen Modulation). Es- where each selection begins and ends. be carried.) sentially the 8 -bit symbols modulate a This information is used by a CD player Players for all these advanced func- bit pattern 14 bits wide (Fig. 4F and G). to cue up individual selections. tions have not yet been issued. In fact, Why is this done? Future applications of the C &D sym- some or the most technically complex The full answer to that question is bol include text data for lyrics; graphics options, like computer graphics and rather complex, but it boils down to the data for computer -type displays on video, are still in the planning stages. fact that about 25 per cent more infor- TV's and monitors; and ultimately vid- mation can be stored on a Compact Disc eo data in conjunction with a video Modulations. At this stage (Fig. 4E), if the 8 -bit symbols are converted to 14- frame -store system. The C &D symbol the frame consists of 33 8 -bit symbols of bit words with certain special proper- can also be made to carry a telephone- digital -audio (24 symbols), parity -check ties. To the CD user this increase of "in- quality digitally encoded voice signal (8 symbols), and control /display data (1 formation density" means longer

ERROR CORRECTION

Analog stylus -in -a- groove recordings No error correction system is perfect, are very susceptible to all sorts of sonic 2 9 4 = 15 however. Eventually enough errors can in occur that exact reconstruction of the degradations from defects the manufac- (A) 7 5 3 =15 turing process or damage inflicted by the transmitted signal is impossible. In the user. What record buyer hasn't had the un- 6 1 8 =15 magic square example, for instance, if four pleasant experience of a bad pressing or 15 15 15 or more numbers were altered in transmis- hasn't heard the noise added by finger- sion there would be no unique solution to prints or scratches on an analog disc's sur- the square. There may be seven) different face. Digital audio offers salvation from = 20 arrays of numbers which will make up a these problems since specially encoded (B) =15 valid magic square. Likewise with the digital signals can be made immune to Compact Disc system. Eventually there what are called "transmission errors." By _15 may be so many errors in the data stream, the incorporation in the pit /land track on a 20 15 15 due to extensive disc damage, that exact CD of extra information which is mathe- correction of the digital -audio data cannot matically redundant to the original digital - Figs. A and B. Magic squares with be performed. A CD player will then inter- audio signal, a Compact Disc player can and without the correct numbers. polate the correct data from valid data by eliminate to a substantial degree the sonic taking an average of the number before side effects of even gross disc damage ransmitting redundant information, a the erroneous digits and the number after like scratches and fingerprints. mathematical summary of the numbers them. The theory of error -correction coding contained in the square. The receiver is In the CD system, if one out of every can get extremely involved, mathematical- able, using this redundant information, to thousand data bits were incorrect (giving a ly speaking, but the basic principles of how calculate and correct more than one trans- bit error rate or BER of 10-3), interpolation error correction is applied in the CD sys- mission error even if one o; the errors oc- will be performed about 1,000 times per tem can be illustrated by a simple analogy. curs with the sum value. Of course, cor- minute. A BER of 10-3 corresponds to a Figure A illustrates what is called a magic recting the sum value isn't helpful if all you very well scratched disc. If only 1 out of ev- square. As you might recall from grade - are interested in is the magic square's ery 10,000 bits is in error (BER = 10-4), a school arithmetic, a magic square is an ar- numbers, but at least that this example typical value for an undamaged CD press- ray of numbers, the rows, columns, and di- shows that the transmission of redundant ing), the interpolation rate drops to about agonals of which all add up to the same information makes the detection and cor- one 16 -bit sample in every 10 hours of number. In this case each row, column, or rection of transmission errors much easier. playing time. diagonal adds up to 15. If you were to The Compact Disc system makes use of There is a very small possibility that an transmit the numbers contained in the a similar, but much more complex, process undetected error will sneak through the magic square along with the sum of any to protect the digital -audio data from trans- CD error -correction system. With the mag- row or column, and if one of the numbers mission errors. About 25 per cent of all the ic square this would mean that several were to be incorrectly received, you would data encoded on a Compact Disc is math- numbers were changed in such a way that still be able to regenerate the magic ematically redundant to the digital -audio the square is still "magic" but not the same square completely and exactly. Why? Be- information. These error -correction sym- one as transmitted. In digital audio, an un- cause you know that each row or column bols are derived by binary computation in detected error can lead to a "click" in the or diagonal adds up to 15. If an incorrect much the same way the sums for the mag- reproduced sound. The CD error correc- number is received as in Fig. B, the rows, ic square's rows and columns were ob- tion system will produce fewer than one columns, and diagonals will not add up tained. Naturally the numerical data on a click for every 750 hours of playing time correctly. The offending number can be CD is not placed in magic squares - with a disc having a BER of 10 -9. In prac- easily located and corrected. The location digitally encoded music doesn't create se- tical terms this means that a reason- is at the intersection of the row and column quences of numbers that are easily fitted ably well cared for Compact Disc press- which do not add up correctly; the correct into magic squares. Instead, the CD en- ing will never generate clicks or pops in value is that number which makes the sum coding system creates unique patterns of playback. The listener is spared from come out correctly. bits which are hard to confuse with one an- these by the actions of the Compact Disc By transmitting the sum value along with other without being able to find and correct error- correction system on the data the numbers in the magic square you were for errors. stream. O

August 1983 45

www.americanradiohistory.comAmericanRadioHistory.Com ...CD DIGITAL AUDIO

playing times. Accompanying this in- which symbol during decoding. 2. The reflected laser beam returns crease of playing time, EFM decreases While the 8 -bit symbols are converted through the same optical system but is the CD system's sensitivity to disc and into 14 -bit EFM words, three additional diverted to a light- sensitive detector (a optical- system defects and production bits are added to each word. These photodiode array). tolerance variations. "merging bits" are calculated to further 3. The photodiode output, after am- The signal created in a CD player's reduce the dc content of the signal. Fi- plification and filtering, is converted photodiode detector circuitry by the nally, the end of the frame is marked by into a squared -off pulse train by the use EFM sequence of pits and lands has two a sync signal of 24 -bits length together of comparator circuitry. more important properties: it has low dc with three merging bits. In all, a frame 4. The pulse train of zeros and ones (0 -Hz) content and it is "self- clocking ". which started out as 192 audio bits now (corresponding to Fig. 4H) is demodu- Low dc content is important because contains 588 channel bits. These are related according to the rules of EFM into the servo systems which keep a CD corded onto a Compact Disc so that a 1 8 -bit symbols carrying audio data, pari- player's laser "on track" utilize low -fre- in the channel -bit sequence turns into ty -check information, and C&D data. quency control and feedback signals. the edge of a pit. A CD player's decoder 5. Data control/error -detection- Any dc content in the signal from the circuits really don't care if they are correction/memory circuits de- inter- photodiode detector can throw off the scanning pits or lands; the circuits are leave and correct the data using the tracking of the laser. (Think of a very sensitive to pit edges. It makes no differ- CIRC decoding rules. long pit or land as having substantially ence whether a logic "1" is encoded as a 6. Sixteen -bit digital -audio samples higher dc content than rapidly alternat- pit or a land. are assembled from the error -corrected ing, small pits and lands.) EFM has very symbols and sent to the 16 -bit digital -to- little 0 -Hz in its waveforms since the Inside a CD Player. A Compact Disc analog converters where they are con- spacing and lengths of pits and lands is player has to undo all the encoding steps verted into analog voltages. strictly controlled. just described in order to recover the 7. The staircase-shaped DAC out- A CD player must synchronize its op- original 16 -bit digital audio samples. puts are smoothed by sharp -cutoff eration with the data coming from the The process, very simply described, fol- lowpass filters and the resulting analog disc and must also synchronize the rota- lows this sequence: signals make up a CD player's audio tion rate of the disc with the operation 1. Light from the player's semicon- output. of the CD- decoding circuits. EFM has ductor laser is focussed through a This brief summary pays short shrift self-clocking properties allowing a CD prism /lens optical system onto the sur- to the complexity and sophistication of player to determine which bit belongs to face of the spinning disc. the operations and circuitry involved. Semiconductor lasers are not universal- ly used components, let alone in mass - -s TIME 1 FRAME market consumer products like CD 5 IA SAMPLING PERIODS players. Steps 4 and make use of com- l 1 plex LSI chips, without which the build- \ ing of a practical and affordable CD Bl,a,co+Ic,,,00lollcocl 1.,Ioc-..c,l 32 BITS PER SAMPLING PERIOD player would be impossible. For exam-

1 1 II ple, the three Sony -developed chips per-

S6 I S6 1 57 I 4 SYMBOLS OF e BITS forming steps 4 and 5 and used by them and several other companies in their i---- , first CD players contain the equivalent 24 AUDIO SYMBOLS gates, not including a 16 1 1 1 1 7,500 I about I I I I of (AUDI°BITS)I 1 1 iÌ I I 1.1 j l l l I 1, -Cc kilobit RAM necessary for the process- 0,---"_ _ "`.-.-'V __ , + 1 c s D ing. Sixteen -bit DACs weren't even c aD ', i a .'---= -"_,PARITY >PARITYII+B PARITY E - -'- available in low -cost monolithic form 33 DATA SYMBOLS (DATA BITS 1it1111013©0it111111111111111/1:1011iO five years ago.

Tracking. That short list of CD- player

1 1 1 0 1 1 F 0 1 0 0 0 0 0 0 0 functions also glosses over two of the 8+ 14(EFM) + 31MERGING) most fascinating applications of servo - G 17 CHANNEL loop techniques: the turning of the disc BITS PER ®® SYMBOL and the tracking of the track of pits 33x17 CHANNEL BITS by the laser /optical system. These two SYNC H-27 SYNC BITS H operations are controlled by digital/ HANNEL BITS) 111111111111IMMOCICEMIIIIIIM0000® 598 CHANNEL BITS analog /electromechanical servo loops of fascinating complexity. They are so í,.00..000.10000.. intricate, in fact, that only a very broad SYNC description of them can be given here. As mentioned before, the rotation x rate of the disc is locked to the frame DR J OR rate, which itself is determined by char- 1 r acteristics of the disc's data stream. Phase -lock techniques are used to keep Fig. 4. Read from top to bottom, this chart summarizes the operations applied the rate of disc rotation generally syn- to a digital audio signal before it gets on a Compact Disc. Read from bottom chronized with the frame rate. Exact up, it the CD player recovery process. summarizes synchrony is not necessary because of

46 Computers & Electronics

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the self -clocking nature of the data systems that accomplish this is very permitted swing is 300 micrometers. modulation scheme; EFM demodula- high. Taking tracking as an example, Yet for accurate decoding, the tracking tion chips can determine where each bit the laser system must be guided over a servo must allow the laser beam to fol- belongs from the signal itself. spiral of pits with a pitch of only 1.6 low the pits to with 0.01 micrometers Servo -loop feedback techniques also micrometers. Disc eccentricity and and also must absorb the effects of vi- keep the laser trained and focussed on player tolerance may cause the track to brations and jolts applied to the player the pit track. The precision of the servos swing from side to side; the maximum chassis. When it comes to focussing the laser beam onto a CD's inner signal surface, INTERLEAVING the focus servo must be able to cope with disc warps of up to 1 millimeter. The focussing system, however, must maintain focus on the signal surface to S T O R T I O N L O W N O I S E- A N D- L O W- DI , tolerances 1,000 times smaller: ±1 ///!//f!//!%/.%r micrometer. I I L O W - N O I S E - A X ;E ,XX X - D S T O R T ON 2 A CD player performs such feats of ' //!!/!//!/f..I..ril....e:07 electromechanical precision by moni- I I 3 L O W- N O I S E- A??????- D S T 0 R T O N toring the shape and /or intensity of the TRANSMIT11* laser beam after it is reflected off the signal surface and back into the optical system. Deviations in the shape or intensity of the beam as detected by a photodiode array are used to move the optical system's objective lens nearer or farther from the disc surface to cope with focussing errors), or to move the optical system as a whole across the surface of the disc (to correct for tracking error). 5 L N E D W S T 0 0 X X X L D 0 0 S N o R N What's Next. Even though the ARRANGEMM. Philips /Sony Compact Disc is a tre- o mendous engineering achievement, it is Fig. A. An interleaving scheme like that only part of the start of what will proba- re shown here is used by the CD system bly be a revolution in information -stor- to reduce effects of large -scale technology: the optical age. In its o o age disc damage. present form, a Compact Disc can hold o 00 N about 16 gigabits of raw data. If the EFM modulation system is used to store computer data, a CD will hold about 7 S 7 0 R T 7 0 N 7 L N 0 7 S E N D 9.14 gigabits or 1.14 gigabytes. If half of that capacity is used as redundant data for error detection and correction, one Interleaving is a process used in the en- terleave the message by rearranging it in Compact Disc could hold about 570 coding of Compact Disc data that reduces rows and reading it out by columns (Fig. A5 megabytes of digital data, about 1,000 the system's susceptibility to what are and 6). The result is a much more intelligi- times the amount of a high- density flop- called "burst errors." These are errors in ble signal; the burst error has been dis- py disc. (The error- correction system the data stream which occur to many bits persed into separated "random" errors for the audio CD, as good as it is, still in succession. They can result from inter- (Fig. A7). lets through too many interpolated and ference to the scanning laser caused by Just as these random errors are much be tolerated in relatively large disc damage (fingerprints, more easily handled by readers of English, undetected errors to long scratches). they are more easily handled by a CD play- data -only applications, thus the very A simple example can easily demon- er's error -correction circuitry. In fact, read- conservative assumption of 50 percent strate the effectiveness of interleaving ers of English supply a "context" to the re- data redundancy.) (Fig. A). Suppose you transmitted the mes- ceived message to make it intelligible. Since its small size increases produc- sage LOW- DISTORTION -AND -LOW- Generally speaking, a CD player does the tion yields and lowers production costs NOISE, but a burst error of six characters same thing with the redundant error -cor- over its larger (12 ") LaserVision video- occured during reception. The receiver rection data placed on the disc. The redun- disc counterpart, don't be surprised if a mathematically de- would then have a hard time figuring out dant data provides the high information capacity of the CD what was meant by LOW- NOISE- A92277- fined and standardized "context" in which system becomes a standard medium for DISTORTION (Figure Al). You could have to interpret random errors in the data made the transmission more immune to stream. mass distribution of software and data the loss of several consecutive characters In the CD encoding process interleaving bases. The enormously larger data -car- by first arranging them in columns, then is accomplished by writing the audio data rying capacity of the 12" LaserVision transmitting them by rows (Figure A4). The into a digital memory and then reading it system can even make it impractical for transmitted signal is thus a regularly out in a different order -the equivalent to mass distribution purposes; who needs scrambled -interleaved- version of the the row /column changeover in the exam- all that data anyway? original signal. If six successive characters ple. A CD player performs the opposite op- Software distribution won't be the process. O are now obliterated, the receiver can dein- eration in the de- interleaving only data application of the Compact

48 Computers & Electronics

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Disc system. Efforts are being made at a is a digital signal processor for audio and, last but certainly not least, soft- number of companies to come up with a signals. Already, relatively slow micro- ware based processing. practical, inexpensive method of record- computers in typical home computers Imagine an audio component looking ing on Compact Discs and optical are being put to good use in audio via much like a popular video -game con- videodiscs. Not only will home digital - specialized Fast -Fourier -Transform sole. Just plug in a cartridge and the sys- audio disc recorders become possible measurement system (like the IQS system becomes a digital ambience synthe- with the development of such technol- tem Julian Hirsch uses in testing audio sizer, or a digital multi -band equalizer, ogy but home computers could easily equipment). Now under development or a tick /pop remover for playing these use a recordable CD for storage of large are ultra -fast, special -purpose old- fashioned stylus /groove recordings. amounts of information. Even an arithmetic processors which, under Technologically such a system is possi- unerasable CD recording system could control of a microprocessor, can be ble today; a commercial system may see be useful. made to perform such audio tricks as fil- the light of day as soon as two years At present, research efforts are being tering, reverberation simulation, com- from now. By then CD players will be directed towards a suitable pression, expansion, click and pop re- supplied with direct digital -audio data laser /recording substrate combination. moval, and sound synthesis and mixing outputs so a direct link from recording The semiconductor lasers used in audio while an audio signal is still in digital studio to a home stereo system's power CD players are too weak to directly form. Among the many advantages that amplifier will be possible. The CD play- "write" on Compact Discs. all -digital signal processing promises ers and recordings available today are All that relates to developments five are no audible degradation in signal to the start of our digital audio future, a fu- to ten years away from reaching com- noise ratio or distortion levels, the capa- ture which promises extraordinary op- mercial reality. Much closer to appear- bility of extraordinarily complex erating flexibility, convenience, ing on your electronics dealer's shelves realtime operations on an audio signal, and -above all -sound quality. 0

A Hands -On Look at Magnavox's not wear out or lose fidelity with repeated playings. Play is from the inside to- FD1000SL Compact Disc Player ward the perimeter. During play, the disc's rotating speed varies from 500 to 200 rpm to maintain an approximately constant linear scanning velocity of 1.2 to 1.4 meters per second. The sonic performance of the compact disc is vastly superior to that of any medium previously available for home reproduction, surpassing even the most advanced professional analog tape recorders. Specifications of the Magnavox FD1000SL, typical of those for most CD players, include a frequency response of 20 to 20,000 Hz ±0.3 dB, dynamic range and signal -to -noise ratio that exceeds 90 dB, and harmonic distortion of less than 0.005% at maximum output. An almost literally zero MANUFACTURED by the parent compa- which we have heard so much in recent flutter percentage is obtained, thanks to ny, Philips of Holland, the Magnavox years. Analog programs are sampled at playback timing being controlled by a Model FD 1000SL is the simplest, most a 44.1 -kHz rate and converted to 16 -bit quartz crystal oscillator. compact, and least expensive of the digital form. The digital information Within the player, a laser scans the "first generation" of CD (Compact controls a laser beam that burns micro- pits on the revolving disc, and its reflec- Disc) players to reach the United States scopic pits into a master disc, forming a tion from or absorption by the disc (a market. It resembles a small, top -load- spiral pattern somewhat like that of a function of the recorded pattern) is ing cassette deck, with a hinged clear - conventional analog record. sensed by a photodiode and forms a se- plastic compartment cover that swings In its final form, the compact disc is ries of digital words. The bit stream is up for loading and removing discs. The silver colored and measures 43%" in di- converted to analog form by 16 -bit D/A sloping upper -front portion of the case ameter. Recording is on only one side, converters and filtered to remove all contains several pushbutton operating the flip side being used for the label. The content beyond 20,000 Hz. Unlike most controls. The machine is enclosed in a recorded surface is protected by a tough CD players that use physical filters, the satin -silver -colored polystyrene case transparent plastic coating, making the FD1000SL employs digital filtering. that measures 12%" W x 101/2" D x disc relatively immune to damage from The operating controls are reminis- 2W' H and weighs approximately 11 lb. normal handling. (Fingerprints, for ex- cent of those on a cassette deck includ- Suggested retail price is $800. ample, have no effect on the sound qual- ing PLAY, PAUSE, and STOP, as well as ity of a digital disc.) And, since no me- high speed FWD and REV SEARCH. Oth- General Description. The CD is the chanical contact is made with the er smaller buttons control special pro- long awaited "digital disc," about laser -read disc during playback, it does gramming features.

50 Computers & Electronics

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When the machine's disc- compart- THD was -70 dB, or 0.03 %. gerprint formed of parallel -ruled lines. ment cover is raised by pressing a but- Intermodulation distortion was also The Magnavox FD1000SL was out- ton at its front -left corner, a spindle is measured at levels of 0 and - 20 dB, standing in this test, being completely exposed onto which the disc is placed, with readings of 0.004% and 0.039% unaffected by any of the errors on the recorded side down. The cover is then respectively (for an SMPTE measure- test disc. closed manually. Pressing PLAY causes ment with 60 and 7000 Hz tones at a 4:1 the disc to spin for a few seconds, sup- amplitude ratio.) Channel separation at User Comment. The Magnavox plying information on the number of 1000 Hz (averaged for the two direc- FD1000SL worked perfectly in extend- separate selections and their precise lo- tions of crosstalk) was 99 dB, and at ed -use tests, playing a number of com- cations on the disc (similar to the action 20,000 Hz it was 93.5 dB. As expected, mercial -music CD records and sampler of a computer /disc catalog). Green the flutter was unmeasurable, reading discs. The programming system was LEDs, visible through the window on the instrument residual of 0.001% on flawless, with the sound beginning ex- the front panel, light up to show the to- our flutter meter (the same reading was actly at the start of each programmed tal number of programs, up to a maxi- obtained using the meter's internal crys- selection. However, the movement of mum of 15. Normally, as the disc is tal controlled 3150 -Hz signal). the pickup to the programmed position, played in sequence from the first selec- We made limited measurements of or under the control of the REV and tion, a second green LED lights below the model's ability to withstand physi- FWD SEARCH buttons, was very slow the track "catalog" to show which pro- cal shock without mistracking. All CD compared to other machines we have gram is being played, advancing at each players are susceptible to losing optical used. For example, if selection #15 was subsequent selection. At end of play, the contact with the recorded track if they the first programmed for playing, the unit shuts down. unit required more than 18 seconds to The CD player may be programmed reach it from the starting point, com- to play tracks in any sequence, by pared to typical times of 1 to 6 seconds choosing either those tracks to be for other machines. played, or those to be omitted from the "The total lack The Compact Disc is in its infancy, of playing sequence. This is done with the course, and whatever opinions one STORE and SELECT buttons, and the of noise, distortion, might form on the basis of incomplete track indicator lights show which have information or hearsay are likely to be- been programmed and which is being crosstalk, or flutter come modified in the future. Our reac- heard at any moment. The high speed tion to it is overwhelmingly enthusias- SEARCH buttons can be used to slew the ...transcena's any- tic. The total lack of noise, distortion, laser pickup to any point on the disc and crosstalk, or flutter results in a listening resume play from that point when the thing previously experience that transcends anything button is released. Although most mu- previously available to an audio sic records have fewer than 15 tracks or available .. enthusiast. programs, the FD1000SL is not limited Not every digital recording is so out- to that number. However, it considers standing (many come from analog mas- everything following the track 15 to be ters, and cannot be better than the mas- part of that program, and cannot be spe- are jarred, and the Magnavox unit is no ter tape), but the medium is everything cifically programmed for higher num- exception. However, it is at least the that has been claimed for it. It will not bered selections. equal of a good record player in this re- replace the LP record for some time, if spect, and has the advantage of being ever, but will supplement it much as Laboratory Measurements. Tests of immune to acoustic feedback that can tape has supplemented records for de- the Magnavox unit were made using cause howling or simply a muddying of cades. Inevitably, the price of the CD special test discs from Philips and Sony. the sound when playing LP records. players will come down to the level of The frequency response (identical for An important consideration for a any reasonably good turntable or cas- both channels) was measured with the compact disc player is its ability to cor- sette deck, and at that time anyone who Philips 410 055 -2 record, and was found rect for bit errors, which are inevitable is serious about good sound will have to be flat within ±0.15 dB from 20 to during playback. All available machines added digital disc capability to his mu- 20,000 Hz, with the variation being in employ fairly elaborate error correction sic system. the form of small "ripples" between systems, typically designed to cope with It is important not to confuse the 4,000 and 20,000 Hz. Output from a "0 interruptions of up to 3000 or more bits Compact Disc with the so-called "Digi- dB" 1000 -Hz recording was 2.03 volts, without loss of tracking or even a no- tal Discs" that have been on the market and the A- weighted S/N (measured ticeable gap or noise in the program. To for some time, and which are really con- with an IVIE IE -30A Audio Analyzer), evaluate the effectiveness of these error ventional analog LP records made from was 99.2 dB referred to that level. The correction circuits, we used a special digital master tapes. They are indeed harmonic distortion, playing the 1000 - Philips test disc on which a wedge - likely to be superior to standard -type Hz test tones of the Sony YEDS 2 shaped portion of the information layer LPs. However, our experience suggests record, which are recorded at levels (recorded with music) is "damaged," so that a CD made from a good analog from 0 to -90 dB, was -95 dB that the length of the dropout can be de- master tape is likely to be much better (0.0018 %) at 0 dB. Since the distortion termined by reference to the disc por- than an LP made from a good digital components remain at about the same tion being played. It also has dots of dif- master. CD discs are expected to sell for amplitude for all signal levels, the per- ferent sizes painted on the transparent $17 to $22 each, a premium price for a centage increased at lower recorded lev- protective layer to evaluate the effect of premium sound and long -lived els. Eventually it was masked by system external dirt or scratches on informa- fidelity. -Julian D. Hirsch noise, but even at a - 20 dB level the tion retrieval, as well as a simulated fin- Circle No. 95 on Free Information Card

52 Computers & Electronics

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W i i v the early 'l'RS -8L Model I con 32 characters by 16 lines (Model Ill keys located on either side of t he hot tutu pWcrs appeared, pionccring wide mode) tow. 'I' sere are also three user- dcfitrd available, modestly priced person 8(1 characters by 24 lines (Model 4 l :menu keys marked t i. t and F3. computer', d_ tractors jercd at the al mode) 'these re used in application programs sence of lower -case fetter. color vide 40 characters by 24 lines (Model 4 Li pro%idc single keystroke data entry. and calcu utr r keyboarr., calling (het mode) The major i-hysical differences be- by the name, "TRASH -8'J" Like "Yat 'the display can slum t he 11tH ASCII tween the neNN computer and the Model kec Dowd e,'- the name suck and h characier set and 64 graphics 111 are internal. In this case, it's what came an tt e:lonate one. The comput characters. .FoN dui 't sec tlra! comas. itself evolved through several modifie The keyboard of the Mode 4 looks The Model 4 contains 64K bytes of tirxt improvements and c.rhanced ve similar to that of the Model III Howev- r sec mentor), which can be upgraded to site's to hc_ortc une of the lutist populi er, the former has several added keys I28K bytes. The additional 64K bytes computer ever built. that were sorely missed by users. One is arc used as memory pseudo -disk called Receutld, when I repo led on my tri a CAI's key, which provides the useful Mcntdi- k. The Model 4 can also be used to Ft. Wotrh and the Rack. Shack Mo caps -lo_k function. The others are the with a Radio Shack hard -disk drive. el 100, 1 n- euiioned how I :also saw, ut i (Kl (Control) key, which was missing This Mentdis: feature is a very inter - de,. wraps in the back °Tice, the late. on the Model Ill keyboard, and stnFr cxting concept. It lets you add a solid- model in this suceesstu. series-0 TkS -80 Mk'del 4. When I looked at the Model 4, ni first thoug¡tts were, "Oh.a white Mod I III, that's lice." When I began to use i however, and understand its fcatur and software. I kept sLying "terrili r,m w...'. -.-. ~ terrific!" So I want to oTer a new ait rsw; , ¿Ww .csAs2+wfa, wdl descried name, -TERRIFIC-SO. for the never and best (if the marque. It is not unit you sit down at the ke board, tun' i on, and snarl lo use th computer th -t the differ-mees becomr e ap-rarent. flic CRT display is 80 char aciers by 24 lires instead o'the 64 char aciers by 16 Ines of the Mindel III. A ludly thcr ale six video mordes: White on black (normal$ _lack oe white 44 characters by 16 lies (Model II mode)

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August 1983 57

www.americanradiohistory.comAmericanRadioHistory.Com RADIO SHACK state "disk" to the system, which keeps TRSDOS. To TRS -80 experts it will to Logical Systems for a new version of its files in memory. Files stored this way look like an operating system that was TRSDOS that was based on LDOS. The can be accessed, read, and written to written for Models I and III, called result is TRSDOS Version 6.0, a really with much more rapidity than ordinary LDOS. The reason for this is that it is fine system. It has features that are disk files on a floppy. You can also use the latest edition of LDOS! found in very few personal computer the Memdisk feature if you only have When Radio Shack first decided to operating systems. 64K of RAM, but its principal use is release its disk system for the TRS -80 Radio Shack has gone to a great deal with the extra bank of memory that the Model I, the decision was made to use a of trouble to ensure compatibility with Model 4 will support. All TRSDOS util- Radio Shack DOS rather than adopt previous versions of TRSDOS and with ities treat the Memdisk files exactly like one of the major disk operating systems LDOS. The version of TRSDOS used any other drive, so you can cos'', BACK- available for licensing. A new system with the Model III is 1.3 and it is com- UP, REMOVE, PURGE, ATTRIB (protect), was written and released as TRSDOS patible with the Model 4. However, and display the directory of the files on 1.0, but it has bugs in it like all the new there are a few differences. An applica- the Memdisk. systems. These were corrected and the tion program running under TRSDOS Like the Model III, the Model 4 system was extended as it went through 1.3 prints larger and fewer characters comes with a parallel printer interface; various updates. on the screen than one running however, there is an optional serial Other companies came out with alter- TRSDOS 6.0. This is because it is de- RS232C interface. nate operating systems for the TRS -80 signed for the 64- character screen on One of the new options of the Model 4 computers, some of them compatible the Model III. TRSDOS 1.3 commands in the ability to use CP /M Plus, the lat- with TRSDOS and some not. Each work slightly differently than TRSDOS est version of the "universal operating gained some users. After a while, those Version 6, but the differences are clearly system." This makes the entire library TRS -80 owners who were considered explained in the manual. of CP /M -80, user controlled software expert came to respect LDOS from Log- The two versions of TRSDOS format available to TRS -80 Model 4 users. ical Systems as a superior DOS. Radio disks differently. There is a conversion Of course, the Model 4 uses the latest Shack now sells it as an alternate for the program on Version 6 called CONV to version of Radio Shack's operating sys- Model III. move files stored on a Version 1.3 tem, TRSDOS, as it major system. This When it came to providing a new op- diskette to a Version 6 diskette. This is is TRSDOS 6.0. This version is substan- erating system for the Model IV, Radio not necessary in order to run Model III tially different than previous versions of Shack broke with its tradition and went programs on Model 4. TRSDOS 6.0 has many more features than I can mention in this article, but some are important because they are not found on many other systems. ATTRIB: Assigns passwords and attributes to a particular file or group of files. The level of file protection can be

Computers & Electronics

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You can program an unlimited number of words and sentences and even adjust volume and pitch. You can make: Adventure games that talk Real sound action games This voice synthesizer is VOTRAX based and has features equivalent to other models costing over $370.00. To make programming even easier, our unique voice editor will help you create words and sentences with easy to read, easy to use symbols. The data from the voice editor can then be easily transferred to your own programs to make customized talkies. FREE - Your choice of $19.95 4" Speaker and Cabinet or $14.95 Voice Editor if you order before June 15, 1983! "15 DAY FREE TRIAL" We have the lowest VIC -20 prices PROTECTO We have over 500 programs (WELOVEOURC1STOME116) E N R P R I Z_ E Visa Mastercharge - C.O.D. TE S - BOX 550, BARRINGTON, ILLINOIS 60010 We love our customers! Phone 312/382.5244 to order

Circle No. 69 on Free Information Card

www.americanradiohistory.comAmericanRadioHistory.Com ...RADIO SHACK

set to be restricted to a person who en- comm: A built -in communications also allows the computer to access Bul- ters a password. Moreover, the protec- program that lets two computers talk to letin Board Systems Networks, and tion can be set up in levels so that a pass- each other via a device, usually the Electronic Mail Systems. While this word can only EXECUTE (Run) a RS232C serial communications. comm type of thing is common, it is rarely program, READ a program, UPDATE a lets the Model 4 be used as a terminal in built into an operating system. It is not program, WRITE to a program, RE- communications and to transfer files to only a money saver, but a great conve- NAME a file, or REMOVE a file. This kind and from another computer. In addition nience that many users will appreciate. of protection is usually only found on it can be used to spool output from an- The function keys FI and F3 actually larger systems. other computer to the printer. comm have many more possible functions

The Micro Color Computer

punctuation marks, plus cursor com- 441l.4 tltttlt it It mands and graphics characters. There is ti tt tttttttitir t a second shift level entered using the tl ts. rltkr6rFrile r. t. CONTROL key. With this level, you can perform single key BASIC commands inscribed above the keys. These include such commands as RUN, CONT, CLOAD, NEW, LIST, CLEAR, CLSD, PRINT, STOP, END, SET, RESET, READ, RESTORE, FOR, NEXT, STEP, INKEYS, INPUT, GOSUB, RETURN, IF, THEN, GOTO, SOUND, PEEK, and POKE. The trig functions and RND function are also available as single -key entries. This is a color computer and can produce nine distinct colors. It can also produce sound under program control. In addition to the graphic characters, the MC -10 can use point graphics with a 64 by 32 grid. This is not very high resolution, but still good for such a small For a long time there has been a rumor course in Micro Color BASIC, a dialect computer. It is like the dancing dog, that Radio Shack was about to come out that is almost the same as TRS -80 Color which can not dance very well, but it is a with a new, low -cost, color computer. I Basic for the CoCo, the Shack's Color wonder that he dances at all! asked about it during a recent trip to Computer. The keyboard has small keys The MC-10 also has the capability of Fort Worth to see some other new mod- (shaped somewhat like Chiclets), but being connected to a tape recorder for els, but all I got from the Radio Shack they are large enough for most pur- data storage and through a serial port people at that time was a smile. poses. The keys cover the usual (DIN connector) to a serial printer. The One day shortly after I returned to QWERTY characters, numerals and Radio Shack TP -10 printer may be home base, I got a phone used. This is a 32- character, call advising that I was 4" -wide printer that's capa- about to receive a package ble of printing all the MC- "that I had asked about." I 10 graphics characters. was as eager as a kid before Further, the Radio Shack Christmas, waiting for UPS LP VII or LP VIII or the to deliver that package. DMP -100, DMP -120, When it did arrive, I opened DMP -200, or DMP -400 it with great expectation. printers may be used. You Inside was a rare jewel, a lit- can also connect the MC -10 tle computer, 2" high by to the CG-115 or FP -215 81/2 " long by 7" wide, called Flatbed Plotters. the Model MC -10 "Micro The MC -10 comes with Color Computer." It comes only 3K of user memory, with an external power sup- but there is a cover plate ply and a TV switch. protecting a card edge con- There is an excellent nector that brings out an ex- manual and a quick refer- pansion bus. ence card to teach you how I liked this small comput- to run and program the lit- er very much at the an- tle fellow. This is really a nounced price of $119. O

60 Computers & Electronics

www.americanradiohistory.comAmericanRadioHistory.Com New Inmac Catalog For more through combinations of the CLEAR key and the function keys. This is used in the information jam-packed comm program to control many corn - munication application functions in- on with computer/ volved in "handshaking" between inter- connected devices, COMM is the advertised program that enables the Model 100 to wp supplies. download its information into the TRS- products, 80 Model 4. equipment CONY: Converts the data files from a Model III diskette to a Model 4 tested, etc., diskette. Yours free! DEBUG: Enters, tests, and runs ma- circle chine language programs for debug- Accuratelycalled "the bible of the industry," it's Fast delivery. 24 -hour shipment. Over- appropriate loaded with great products and ideas for your night emergency shipments available. ging. This is a very valuable function. personal computer, minicomputer or word- 45- dartrial. Full refund if not completely SPOOL: Establishes a FIFO (First -in, processing system. You'll enjoy: sotisfietl. number 00e -stop shopping. Over 2,000 products Guaranteed quality. All products field - First -out) buffer for a device, usually a tochoose from tested to highest standards. printer. It enables the computer to print Easy ordering. Mail, phone, or TWO. l.ewer skipping tuts. 8 fully stocked on Verbal PO's welcome. distribution centers serving the U.S. data while other operations are per- For fastest delivery of your free 100 -page inmac formed on the computer. catalog, postpaid call 1 (800) 547-5444.1 (800) 547 5447 in California. FORMS: Another unusual and useful command in TRSDOS 6.0. It allows Free r printing a form larger or smaller than a , Dept., 2465 Augustine Drive, Santa Clara, CA 95051 N standard -size page. Another feature not Information InmanCatalogPlease be sure to irdudetour pharenuntber. often found in an operating system, but ( ) ö nice to have. Card. NAME PHONE JCL: The TRSDOS Job Control Lan- COMPANY guage is one of the most powerful fea- ' ADDRESS 1 tures of the TRSDOS 6.0. It permits the CITY STATE ZIP writing 1 of programs that perform a vari- Circle No. 10 on Free Information Card ety of functions such as FORMAT, and BACKUP and have TRSDOS run them when a single command is typed in. This makes the system much more "user friendly." These features and many others cause people to applaud TRSDOS 6.0 as a major contribution to personal computing software. It not only provides a jump- McIntosh ing-off place for new and better systems, it does it without obsoleting the large STEREO CATALOG stock of TRS -80 programs already in the Library. and FM DIRECTORY In addition to providing a selection of Get all the newest and latest information on the new operating systems, Radio Shack has McIntosh stereo equipment in the McIntosh catalog. In also provided a choice of langauges for addition you will receive an FM station directory that every purpose. These include MBASIC, covers all of North America. BASIC Compiler, and FORTRAN from Microsoft; CBASIC from Digital Research; Pascal from Alcor; Radio Shack Graphics BASIC (649 X 240 resolution); RM COBOL from Ryan McFarland; and an Assembly Language Development System including Macro Assembler. r i Adding up the number of application McIntosh Laboratory Inc. CE programs, languages, and systems that East Side Station P.O. Box 96 Binghamton, N.Y. 13904-0096 are available for the Model 4 in TRSDOS 1.3, CP/M -80, and LDOS, SEND this has to be one of the best -supported NAME new computers ever released. In addi- ADDRESS tion, Radio Shack has converted its line TODAY! of business software into Model 4 CITY STATE ZIP format. L J We say again, the Model 4 is really If you are in a hurry for your catalog please send the coupon to McIntosh. the TERRIFIC -80. -Stan Veit For non rush service send the Reader Service Card to the magazine. CIRCLE NO. 31 ON FREE INFORMATION CARD

August1983 61

www.americanradiohistory.comAmericanRadioHistory.Com LAST NIGHT WE EXCHANGED LETTERS WITH MOM,THEN HAD A PARTY FOIL ELEVEN PEOPLE IN NINE DIFFERENT STATES AND ONLY HADTO WASH ONE GLASS...

That's CompuServe, The CompuServe's multi- channel CB and CompuServe. CompuServe connects simulator brings distant friends together with almost any type or brand of Personal Communications and Network For Every Computer and gets new friendships started. You personal computer or terminal can even use a scrambler if you have a many communicating-word processors. Owner secret you don't want to share. Special To receive an illustrated guide to And it doesn't matter what kind interest groups meet regularly to trade CompuServe and learn how you can of computer you own. You'll use information on hardware, software and subscribe, contact or call: CompuServe's Electronic Mail system hobbies from photography to cooking (we call it Email') to compose, edit and and you can sell, swap and post personal CompuServe business notices on the bulletin board. send letters to friends or Consumer Information Service, P. 0. Box 20212 associates. The system delivers any There's all this and much more 5000 Arlington Centre Blvd., Columbus, OH 43220 number of messages to other users on the CompuServe information Service. 8004848 -8990 anywhere in North America. All you need is a computer, a modem, In Ohio call 614 -457-0802

An H&R Block Company Circle No. 60 on Free information Card

www.americanradiohistory.comAmericanRadioHistory.Com agio-Q4acie DATA CONVERTER FOR THE APPLE II By Robert C. Nicklin Part 2: Checkout, calibration, and use LAST month, we discussed the princi- played on- screen. As each data line is from DO through D7 and load and run ples of A/D and D/A conversion and ungrounded, it should display a 1 on the Program 2 to test the output. For described a converter for the Apple II. screen. If it doesn't, the interface adapt- Byte =0, there should be no voltage (0 Here are the software and instructions er most likely isn't plugged into slot 5 of volt) between each data line and needed to operate the converter. the computer and /or the program ground; for Byte =255, each data line hasn't been correctly entered. If the should be at +5 volts; for Byte= 55, DO Checkout & Calibration. Plug one problem still persists after making sure through D7 should be 10101010, etc. end of a ribbon cable with DIP headers that the adapter is in slot 5 and the pro- Load and run Program 3 to test con- on each end into Port A at SO4 on the gram has been properly entered, use a trol line CA2. Making measurements at interface adapter. Then, making sure dual -trace oscilloscope to check the IC7 .16, CA2 should be 0 V for PC =12 and the Apple computer is powered down, delay circuit. For proper operation, the +5 V for PC =14. install the VIA in slot 5 of the computer. signal observed at pin 6 of IC7 should be To test Port B, power down the com- Plug the other end of the cable into a delayed by about 180 ns with respect to puter and move the DIP cable to SO3. solderless- socket breadboard and use the signal at pin 1. Repeat the above three tests, changing wire jumpers to connect DO through D7 Remove the ground connections the POKE and PEEK addresses for to ground at pin 11. DDRB and ORB as Switch on the com- detailed in Table I. puter and wait for the The PCR address prompt to appear on- doesn't change, but screen. Measure the the values for PC voltages at pins 50, 33, change to 192 for 0 V and 25 of the comput- and 224 for +5 V to er's bus connector; operate CB2. they should read + 12, Having ascertained -12, and +5 V, proper port and con- respectively. trol operation, remove For the following the ICs from the Data discussion, the inter- Converter assembly, face is assumed to be power down the com- plugged into slot 5 of puter, and plug the the computer and all 16 -pin DIP cable into data lines are 503, the Port B con- grounded. nector. Power up the Enter and run Pro- computer and con- gram 1 to test the in- firm that +12, put to Port A. Dis- -12, and +5 V are played on- screen present at the ap- should be a running propriate IC sock- column of Os read in et pins. (Bear in from Port A. One at a mind that under time, remove the data these no -load condi- line jumpers from tions some non -power ground and note the pins will measure change in status dis- high.) Having con-

August1983 63

www.americanradiohistory.comAmericanRadioHistory.Com DATA CONVERTER

PROGRAM 1 PROGRAM 5 firmed that the proper voltages are present at the appropriate pins, power 100 REM PROGRAM #1 100 REM PROGRAM #5 down the computer, insert the ICs in 120 REM PORT A INPUT TEST 120 REM AUDIO AMP TEST their respective sockets (take care to ob- 130 REM 6522 VIA IN SLOT 5 130 REM 6522 VIA IN SLOT 5 serve proper orientation), and power up 150 150 once again. 160 REM SET PORT A DDRA 160 REM SET DDRB FOR OUTPUT 49362,255 Connect a voltmeter to J2 and ground FOR INPUT 170 POKE D =0 180 the center connector of J1 to begin test- 170 POKE 49363, D 190 REM SET CB2 HIGH SO DAC amplifier. Set the 180 ing the analog 190 200 REM CHIP ENABLE IS LOW project's GAIN switch to 1 and adjust 200 REM READ ORA WHILE 210 POKE 49372,224 trimmer R3 for a 0 -V output. Set the CHANGING 220 GAIN switch to 500 and adjust R3 for 210 REM JUMPERS FROM DO -D7 230 INPUT "PAUSE BYTE = ? ";P minimum positive output. To check cal- TO GROUND 240 POKE 49360,0: GOSUB 290 ibration of the GAIN control, remove the 220 PRINT PEEK (49375) 250 POKE 49360,255: GOSUB 290 short from across JI and replace it with 230 260 GOTO 240 a 10,000 -ohm potentiometer connected 240 FOR PAUSE - 1 TO 200: NEXT 270 END 250 GOTO 220 290 FOR PAUSE = 0 TO P: a (use the wiper and one across D cell NEXT: RETURN make connections end lug of the pot to PROGRAM 2 to the converter circuit) to provide the dc signal input. Make up a table of input 100 REM PROGRAM #2 vs for of the six positions of output each 120 REM PORT A OUTPUT TEST PROGRAM 6 the GAIN switch for use in making soft- 130 REM 6522 VIA IN SLOT 5 ware corrections to compensate for 150 : 100 REM PROGRAM #6 nonlinearities in gain. 160 REM SET PORT A DDRA 120 REM DIGITAL I/O TEST If you have access to an audio oscilla- FOR OUTPUT 130 REM 6522 VIA IN SLOT 5

tor and an oscilloscope, feed sine waves 170 D =255 150 : into JI and monitor J2 to observe that 180 POKE 49363,D 160 REM SET DDRB FOR INPUT 49362,0 the amplifier has reasonably flat re- 190 : 170 POKE sponse from dc to 15 kHz. 200 INPUT "BYTE "; B 180 : Enter and run Program 4 to check 210 REM OUTPUT BYTE TO 190 REM GROUND DO OR D7 (4 WAYS) D/A conversion. A voltmeter connect- PORT A 220 REM TEST DO -D7 WITH 200 PRINT PEEK (49360) ed between DAC J5 and ground should 210 GOTO 200 indicate 0 V when DB is 0 and 2.55 V VOLTMETER when DB is 255. 230 POKE 49375, B 240 GOTO 200 Use Program 5 to generate a square wave whose pitch is controlled by the PROGRAM 3 PROGRAM 7 value of P for checking the audio amplifier. This square -wave signal can be oh- 100 REM PROGRAM #3 100 REM PROGRAM #7 served at J5 with a scope. 120 REM PORT A CONTROL 120 REM ADC TEST Program 6 sets DDRB =O for all in- 125 REM LINE CA2 TEST 130 REM 6522 VIA IN SLOT 5

puts for testing the digital I/O lines. D1 130 REM 6522 VIA IN SLOT 5 150 : through D6 will float high while DO and 150 160 REM SET DDRB FOR INPUT D7 are checked. The running display 160 REM CA2 GOES LOW ON 12 170 POKE 49362,0 produced by this program will change 170 REM AND HIGH ON 14 180 :

: 190 REM MAKE READ HIGH according to whether DO or D7 is short- 180 190 INPUT "PCR BYTE = ? "; PB (WITH CB2) II). ed (see Table 200 POKE 49372, PB 200 REM AND START A/D conversion is tested with Pro- 210 GOTO 190 CONVERSION gram 7. This simple diagnostic program 210 POKE 49372,224 is written in BASIC, which is slow PROGRAM 4 220 enough to complete a conversion before 230 REM MAKE READ LOW (WITH CB2) being read. Results are continuously 100 REM PROGRAM #4 REM PREPARE TO READ displayed on- screen. With JI grounded 120 REM DAC TEST 240 CONVERSION and the GAIN switch set to 1, the reading 130 REM 6522 VIA IN SLOT 5 250 POKE 49372,192 dc and about 127 on ac. 150 : should be 0 on 260 160 REM SET DDRB FOR OUT Connect the pot /D -cell assembly to JI REM READ ADC 170 POKE 49362,255 270 and slowly vary the setting of the pot 280 PRINT PEEK (49360) 180 : (dc input level). The on- screen display 290 190 REM SET CB2 HIGH SO DAC changes. Make sure 300 GOTO 210 should follow the 200 REM CHIP ENABLE IS LOW the -9 -volt reference is present at pin 2 210 POKE 49372,224 of IC2. A scope connected to TRIG J6 220 should reveal CB2 going high for about 230 REM OUTPUT DB TO DAC one -third or one -quarter of the pulse cy- AR ORB

cle. Without this pulse, no A/D conver- 240 INPUT "DAC BYTE . ? ";DB sion is possible. 250 POKE 49360, DB Set Ac /DC switch S2 to Dc for ampli- 260 GOTO 240

64 Computers & Electronics

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www.americanradiohistory.comAmericanRadioHistory.Com ...DATA CONVERTER

tude calibration. Apply the full poten- (7.01/1.46), although the A/D convert- cycle of the square wave and multiply tial from the D cell to Jl. Assume this to er actually "sees" 7.01 V. Measure ref- by the frequency to obtain A/D conver- be 1.46 V, the voltmeter will indicate erence voltage VREF between J3 and sion sampling rate. If the A/D timing 7.01 V with the GAIN switch set to 5. ground. Assume it to be 8.56 volts. With bytes are changed, this frequency cali- This means that gain is actually 4.80 full scale for the converter being 255 for bration can be performed and recorded any VREF, the A/D converter will pro- for a range of digitizing rates. duce 209 (7.01/8.56). Working back- ward, we find that VINPUT = (A /D Operation Under Assembly Lan- TABLE 1 -6522 VIA For A/D or D/A at rates of less ADDRESSES, SLOT 5 output /gain) X (VREF /255). This guage. means that conversion accuracy de- than 50 samples per second, such BA- in 1 Starting address 49360 ($CODO) pends on voltmeter accuracy. Often, SIC programs as those Programs DDRA 49363 true ViNPUT isn't needed, since relative through 7 are adequate. To realize rates ORA 49375 amplitude will be sufficient. up to 17,000 samples per second for DDRB 49362 Frequency accuracy requires use of a A/D and output rates to 33,000 bytes ORB 49360 frequency counter to set a square -wave per second with D /A, both converters PCR 49372 generator to 1000 Hz (the actual fre- must be operated with assembly -lan- ACR 49371 quency isn't important as long as it is guage programs. Table III is for A /D, known). Feed the square waves into JI while Table IV is for D/A code. is similar TABLE DIGITAL I/O TEST and use Table III to run the A/D con- Operation of Table III code II- verter fast enough to digitize the wave- to operation of Program 7. Port A form. The Apple monitor program can DDRA is set for input with the A/D D7 D6 D5 D4 D3 D2 D1 DO Screen be used to "look at" the bytes in memo- converter getting a high on its Read line 0 1 1 1 1 1 1 0 126 way to do this is to use a via CA2 to initiate conversion. A loop 0 1 1 1 1 1 1 1 127 ry. Another section 1 1 1 1 1 1 1 0 254 short BASIC program written to PEEK of at least 20 µs allows the A/D

1 1 1 1 1 1 1 1 255 the bytes onto the screen. In either case, to convert the input signal. When the count the number of bytes per complete Read line goes low, via CA2, conversion

TABLE III -ADC ASSEMBLY LANGUAGE

$9300 A9 00 START LDA $00 02 A8 TAY INITIALIZE Y 03 85 FE STA MEM SET START OF DATA STORAGE- 05 A9 88 LDA $88 ALTER FROM BASIC 07 85 FF STA MEM+ 09 A9 00 LDA $00 MAKE PORT A ALL INPUTS OB 8D D3 CO STA DDRA OE 78 EA EA SEI 11 A9 OE ADC LDA $0E MAKE READ HIGH, START CONVERSION 13 BDDCCO STA PCR 16 A2 05 LDX $05 GIVE ADC> 20 MICROSECONDS 18 CA WAIT1 DEX TO CONVERT 19 DO FD BNE WAIT1 1B A9 0C LDA $0C MAKE READ LOW, PREPARE TO 1D 8DDCCO STA PCR READ ADC 20 AD DF CO LDA ORA READ ADC 23 91FE STA (MEM), Y STORE DATA 25 20 40 93 JSR MSEC DELAY BETWEEN SAMPLES 28 C8 INY 29 DO E6 BNE ADC 2B E6 FF INC MEM+ PREPARE TO FILL NEXT MEMORY PAGE 2D A6 FF LDX MEM+ WITH DATA 2F E0 92 CPX $92 CHECK FOR END OF MEMORY 31 DO DD BNE ADC 33 58 CLI $9334 60 RTS

$9340 A9 00 MSEC LDA $00 SET VIA TIMER 2 FOR ONE -SHOT 42 BDDBCO STA ACR TIME INTERVAL 45 A9 E8 LDA $E8 $03E8 GIVES ABOUT 1 msec 47 8DD8CO STA T2L INTERVAL -POKE CHANGES 4A A9 03 LDA $03 FROM BASIC 4C 8D D9 CO STA T2H 4F A9 20 LDA $20 TIMER 2 INTERRUPT FLAG MASK 51 2C DD CO WAIT2 BIT IFR IS FLAG SET? 54 FO FB BEQ WAIT2 IF NOT, THEN LOOP 56 ADDBCO LDA T2L TIMED OUT-CLEAR FLAG $9359 60 RTS

66 Computers & Electronics

www.americanradiohistory.comAmericanRadioHistory.Com TABLE IV -DAC ASSEMBLY LANGUAGE

$9200 A9 FF LOA $FF SET UP PORT A FOR OUTPUT 02 8D D3 CO STA DORA TO DAC 05 A5 FE LDA FE SAVE CONTENTS OF TWO ZERO PAGE 07 48 PHA ADDRESSES USED FOR MEM AND MEM+ 08 A5 FF LDA FF IN (IND), Y ADDRESSING OA 48 PHA OB EA NOP OC A9 00 START LDA $00 INITIALIZE Y FOR (IND), Y MEMORY SCAN OE A8 TAY OF 85 FE STA MEM START DATA READOUT AT $8800 11 A9 88 LDA $88 13 85 FF STA MEM+ 15 EA NOP 16 78 SEI MAKE DAC OUTPUT GLITCHLESS 17 A9 OC LDA $0C MAKE CA2 LOVV TO TURN OFF DAC 19 8D DC CO STA PCR 1C A9 OE LDA $0E MAKE CA2 HIGH TO TRIGGER SCOPE 1E 8D DC CO STA PCR AND ENABLE DAC 21 EA NOP

NOTE: CA2 GETS INVERTED BEFORE IT GETS TO DAC, BY 7416 HEX INVERTER

22 B1 FE DAC LDY (MEM),Y DISPLAY MEMORY CONTENTS 24 8D DF CO STA ORA ON SCOPE 27 20 50 92 JSR DELAY 2A C8 INY DAC GETS ONE PAGE A- A TIME 2B DO F5 BNE DAC 2D E6 FF INC MEM+ MOVE TO NEXT PAGE 2F A6 FF LDX MEM+ TO CHECK FOR TOP LIMIT 31 EO 92 CPX $92 33 DO ED BNE DAC 35 EA NOP 36 58 CLI 37 C6 FD DEC NSCAN HAVE N SCANS BEEN COMPLETED? 39 A5 FD LDA NSCAN 3B DO CF BNE START 3D EA NOP 3E 68 PLA 3F 85 FF STA FF REPLACE ZERO PAGE CONTENTS 41 68 PLA 42 85 FE STA FE $9244 60 RTS $9250 A2 02 DELAY LDX $N DELAY BYTE 52 CA DEX 53 DO FD BNE 55 60 RTS TABLE V -CLEAR MEMORY ASSEMBLY LANGUAGE

$9280 AO 00 LOY $00 INITIALIZE Y FOR (MEM),Y 82 A5 FE LDA FE SAVE CONTENTS OF TWO ZERO PAGE 84 48 PHA MEMORY LOCATIONS USED FOR 85 A5 FF LDA FF (IND), Y ADDRESSING OF 87 48 PHA MEM AND MEM+ 88 A9 88 LDA $88 START CLEARED AREA AT PAGE $88 8A 85 FF STA MEM+ 8C A9 00 LDA $00 8E 85 FE STA MEM 90 A9 00 LDA $00 BYTE TO FILL MEMORY 92 91 FE CLEAR STA (MEM),Y 94 C8 INY FILL MEMORY 95 DOFB BNE CLEAR 97 E6 FF INC MEM+ 99 A6 FF LDX MEM+ 9B E0 92 CPX $92 9D DO F3 BNE CLEAR 9F 68 PLA REPLACE ZERO PAGE CONTENTS AO 85 FF STA FF A2 68 PLA A3 85 FE STA FE A5 60 RTS

August 1983 67

www.americanradiohistory.comAmericanRadioHistory.Com DATA CONVERTER

TABLE V1 -APPLE ADC LOCATIONS (SLOT 5 ASSUMED) is latched so it can be read out from ORA. The sample is stored and a delay Address subroutine is called. The program deter- Hex Decimal Explanation mines if alotted memory is full; if it isn't, it sends a Read high for another $9300 37632 Start of ADC Assembly language program conversion. 9306 37638 Set beginning of data storage Operation of the D/A converter un- pages $88 -$91 (136 -145) der the listing given in Table IV pro- 930C 37644 DDRA LOW $D3 (211) DDRB LOW $D2 (210) ceeds as in the BASIC listing in Pro- 930D 37645 DDRA high $00 (192) DDRB HIGH $C0 (192) gram 7. Port A DDRA is set for output. 9312 37650 READ HIGH (CA2 OR CB2) START CONVERSION* A high on CA2 triggers a scope con- TO READ CONVERSION* 931C 37660 READ LOW PREPARE nected to J6 and, after inversion by IC4, ORA LOW $DF (223) ORB LOW $D0 (208) 9321 37665 pulls low the D/A converter's Chip En- 9322 37666 ORA HIGH $C0 (192) ORB HIGH $C0 (192) able line. A byte is then fetched from 9330 37680 SET END OF DATA STORAGE MEMORY 9346 37702 T2L BYTE memory and sent to the D/A converter 934B 37707 T2H BYTE 'via ORA. The program then checks 9359 37721 LAST OP CODE (90 BYTES) whether or not the memory specified has been scanned; if it hasn't, another low high byte is sent to ORA. After completing a CA2 $0C $0E set number of scans, the program re- 12 14 turns to the routine that called it. Table IV can be used to clear a specif- CB2 $C0 $E0 ic block of memory before filling it with 192 224 data from the A/D converter, or before storing the output from the D/A converter. Although memory clearing can be performed from BASIC, it's too slow TABLE VII -APPLE DAC LOCATIONS (SLOT 5 ASSUMED) for more than a 1K-byte block of memory used for repeated measurements. Address Hex Decimal Explanation Operation Under BASIC. The various assembly -language programs presented $9200 37376 BEGINNING in this article are best used as subrou- 9203 37379 DDRA LOW BYTE (211) DDRB LOW BYTE (210) tines called from a BASIC driver pro- 9204 37380 DORA HIGH BYTE (192) DDRB HIGH BYTE (192) gram. It's easy to set memory limits and 9212 37394 SET BEGINNING OF SCAN -PAGE 136 TO 145 data rates and change to the alternate 9218 37400 SET CA2 LOW (12) SET CB2 LOW (192) port by POKEing new values into the 921D 37405 SET CA2 HIGH (14) SET CB2 HIGH (224) assembly -language code. This permits 37413 ORA LOW BYTE (223) ORB LOW BYTE (208) 9225 use of the fast assembly -language 37414 ORA HIGH BYTE (192) ORB HIGH BYTE (192) 9226 routines without having to be familiar 9232 37426 SET END OF SCAN (SCAN UP TO THIS PAGE) 9251 37457 SCAN DELAY BYTE (0 TO 225) with assembly-language programming. 9257 37463 LAST OP CODE The BASIC listings for Apple DAC, 00FD 253 NUMBER OF SCANS BEFORE RETURN KEY IS Apple ADC, and Clear Memory con- CHECKED tain the three assembly -language programs discussed. Tables VI, VII, and VIII list the POKE values required to tailor the routines to your purposes. These programs all assume you're us- TABLE VIII-CLEAR MEMORY LOCATIONS ing an Apple II Plus computer with 48K (SLOT 5 ASSUMED) of user RAM and slot 5 in the computer. The memory map in Table IX reveals Address where everything is stored. If you're us- Decimal Explanation Hex ing a disk drive, you can keep the DOS from overwriting the machine -language BEGINNING OF PROGRAM $9280 37504 program by booting the DOS, setting 37513 SET HIGH BYTE, START OF CLEARED AREA 9289 HIMEM:34815 and then loading the 928D 37517 SET LOW BYTE, START OF CLEARED AREA 9291 37521 BYTE TO FILL MEMORY WITH BASIC program. This protects opera- 929C 37532 PAGE NUMBER FOR END OF CLEARED AREA tion by putting data storage and ma- -DON'T CLEAR BEYOND THIS (PAGE 146 MAXIMUM) chine language above BASIC and below 34816 -PAGE 146 ($92) MEANS $91FF IS LAST LOCATION the DOS. Memory locations through 37375 are for data storage; THAT WILL BE CLEARED 37376 through 37721 for the D /A, 92A5 37541 LAST BYTE OF PROGRAM Clear, and A /D; and 37722 through 38399 for data or expansion. NOTE: $8800 -$91 FF ARE SET ASIDE FOR ADC, DAC. DATA STORAGE $9200 -$93FF ARE SET ASIDE FOR DAC, CLEAR MEMORY AND ADC The three assembly -language ASSEMBLY LANGUAGE PROGRAMS routines can be easily relocated, since

68 Computers & Electronics

www.americanradiohistory.comAmericanRadioHistory.Com Hire a except Apple ADC, they contain no ab- GAIN switch for a peak -to -peak signal solute addresses. Because delay routine level of less than 9 volts. Connect a lead MSEC calls $9326 (memory location from TRIG J6 to the scope's trigger input fast 37670) and $9327 (location 37671), Ta- and adjust the scope for a triggering. ble III must be changed to fit the new lo- RUN the program while holding a note. cation. If slot 5 in the computer isn't The computer will capture and dis- used, the correct VIA address for the play 1280 samples of the waveform. thinker. slot must be POK Ed. Since these samples are stored in memory, they can be SAVEd on disk, written Capturing Waveforms. The Wave- to a printer, or plotted on a strip chart, form Program combines D /A, A /D, or the waveform could be Fourier ana- and Clear routines and illustrates use of lyzed if desired. the VIA and Data Converter. The pur- With some minor changes in the BA- pose here is to capture an audio wave- SIC program, 256 samples of each of 10 form and display it on the CRT screen different waveforms could be captured of an oscilloscope. and selectively analyzed. Alternatively, Load the Waveform Program, con- they could be plotted in HIRES with nect a microphone to JI and a scope to about a 25% loss in vertical resolution, J2, and set S2 to AC. Sing a steady "o -o- on 192 vertical points for 256 from the o-h-h-h" tone into the mic and set the A/D converter.

TABLE IX -APPLE DATA CONVERTER MEMORY MAP HEX DECIMAL

$FFFF APPLE USES 65535 $C100 49408

$COFF PERIPHERAL CARD I/O SPACE FOR 49407 $C080 6522 VIA (8 SLOTS) 49280

APPLE USES

$BFFF DOS 49151 $9600 38400

$95FF SPACE FOR MACHINE LANGUAGE 38399 $935A PROGRAMS (MLP) OR CONVERTER DATA 37722 5 MHz CPU Card $9359 ADC MLP 37721 Intel 8085A -2 microprocessor Hardware $9300 37632 floating point Performs calculations six times faster than other CPUs On -board monitor in 80 BYTES FOR MLP PROM 1K RAM scratch pad Keyboard or RS232C terminal Variable clock frequency $92A5 CLEAR MEMORY MLP 37541 $9280 37504 PRICE -$450 (California residents add 6% sales tax) 40 BYTES FOR MLP Call or write Artec for details. $9257 DAC MLP 37463 $9200 37376

$91 FF ADC /DAC DATA STORAGE 37375 $8800 (PAGES 136 -145) 34816

$87FF FOR BASIC PROGRAMS 34815 $6000 (SET HIMEM:34815) 24576

$5FFF HIGH RESOLUTION GRAPHICS 24575 $2000 8192

$1FFF FOR BASIC PROGRAMS $0000 8191 ARTEL CLCCTRONICS, INC. 3072 605 Old County Rd., San Carlos, CA 94070 Telephone (415) 592 -2740 $OBFF APPLE USES 3071 CIRCLE NO. 55 CN FREE INFORMATION CARD $0000 o

August 1983 69

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ATARI

CBM 64 ATARI14 HOME COMPUTER $239m3 600XL (15K Ram) s149. Call for Price & Information on 8OOXL (64K Ram) NEW Franklin 1000. 1100. 1200 and VIC 20 $99. other NEW Franklin Hardware & 1200XL(64K Ram) NEW Software & Special System Pricing 1400XL(54K Ram) NEW MICRO -SCI CALL ON 1450XL(64K Ram) NEW DISK DRIVES FOR EXECUTIVE 6 1010 Program Recorder $74.00 APPLE & FRAN KIN 102040 Col. Printer /Plotter $249.00 A2 $249.00 PORTABLE 1025 80 Col. Printer 5449.00 A40 $349.00 1027 LetterOuality Printer $299.00 470 $459.00 COMPUTER 1050 Disk Drive $379.00 C2 Controller $79.00 PEßCOM 1 850 Interface $169.00 1 520 Color Printer /Plotter _ $169.00 1030 Direct Connect Modem... CALL C47 Controller $69.00 Printer....$219.00 1525 80 Column CX30 Paddles $12.00 AT88-S 1 $369.00 VISICORP 1 530 Datasette $69.00 CX40 Joystick $8.00 for Apple,IBM & Franklin 1541 Single Disk Drive $249.00 ÁT88-Al $299.00 AT88 $569.00 CX42 Remote Joystick CALL Visidex $189.00 1600 VIC Modem $59.00 -S2 AT88 PD $419.00 CX77 Touch Tablet $69.00 Visit ile $189.00 1610 VIC Term 40 $49.00 -S1 AT88 -S2 PD $669.00 CX80 Trak Ball $49.00 Visiplot $159.00 1650 AD /AA Modem $89.00 AT88-DOA $139.00 CX85 Keypad $105.00 Visiterm $89.00 1 701 14" Color Monitor .... $249.00 AT44-S1 $579.00 CX418 Home Manager $69.00 Visitrend/Plot $229.00 1311 Joysticks (each) $5.99 AT44 -S2 $969.00 CX488 Comunicator Il $229.00 VisiSchedule $229.00 1312 Paddles $11.99 Texas Instruments Drive $369.00 KX7098 Atari Accountant $209.00 Plan $189.00 1110 VIC 8K $42.00 Desktop KX7101 Entertainer $69.00 _.$179.00 1111 VIC 16K $69.00 Vistcalc(Applell.CBM.IBM) KX7102 Arcade Champ $75.00 Visicorp prices for IBM may vary slightly. 1011 RS232 Interface $42.00 CONTINENTAL 1211 Super Expander $53.00 TIMEX SOFTWARE 1906 Super Alien $12.00 1910 Radar Rat Race $12.00 SINCLAIR 1000 Tax Advantage (Apple /Atari) $45.00 1917 VooDoo Castle $15.00 Home Accnt. (Apple /Atari) $59.00 $44.95 1922 Cosmic Cruncher $15.00 16K Memory 1st Cl. Mail /Form Letter(Apple) $79.00 2040 Printer $99.95 $14.95 1923 Gorf $15.00 The Book of Apple Vu -Galt $17.95 1924 Omega Race $15.00 The Book of Atari $14.95 Book Manager $13.95 110 VIC 20 Reference Guide $15.00 Check The Book of Apple Graphics $14.95 $14.95 ORBYTE SOFTWARE CBM 64 Reference Guide $18.00 Organizer FLOPPY DISKS Budgeter $13.95 Graphics $12.99 MAXELL MODEMS Stock Option $14.95 Home Budgeter $12.99 MD 1(Box of 10) $32.00 HAYES Loan & Mortage Amortizer S12.95 Home Inventory $12.99 Tax MD II(Box of 10) $44.00 Smart $219.00 Mindware Printer $109.00 Income $14.99 Smart 1200 (1200 Baud) S549.00 Mega Mind $15.99 FD I (8") $40.00 MONITORS Chronograph $199.00 Salvo $12.99 FD 11 ¡8" OD) $50.00 AMOEK Micromodem 100 $309.00 The Ouiz $12.99 VERBATUM 300G $159.00 Micromodem II $279.00 Words $1 2.99 51/4" SS DD $26.00 300A $169.00 Micromodem ll)with term) S299.00 51/4" DS DD $36.00 310A $169.00 Smart Com II $99.00 ELEPHANT Color I $279.00 Smart 12008 $469.00 Color 1 plus 299.00 PC-1500 51/4" SS SD S18.95 NOVATION 51/4" SS DD $24.99 Color 11 $449.00 SHARP POCKET J-Cat $119.00 51/4" DS DD S29.99 Color III $349.00 COMPUTER Cat $144.00 GORILLA HEWLETT D -Cat $159.00 12" Green $89.00 PAC KARO 103 Smart Cat $189.00 Apple Cat II $279.00 BMC 103/212 Smart Cat $439.00 12" Green $85.00 [gypI 9191 13" Color $299.00 41 CV 212 Apple Cat II $609.00 Apple Cat 11 212 Uograde $309.00 TAXAN ANCHOR 12 N Green $129.00

Mark I (RS -232) $79.00 12 A Amber $139.00 $209 ZENITH PC -1500 $169.00 Mark II (Atari) $79.00 Mark III (T.I. -99) $109.00 ZVM 121 $95.00 PC -1250 S139.00 ZT -1 Terminal $369.00 -150 Printer. Plotter & Cassette H . . Mark IV (CBM -PET) $125.00 CE P75. $749. Interface for 1500 $172.00 HP 41C $146.00 Mark V ¡Osborne)...... $95.00 U.B.I. $99.00 CE 125 Printer /Micro Cassette HP 10C $52.00 Mark VI (IBM -PC) $179.00 Pi 1, 9" Green Mark VII (Auto Ans. /Auto Dial) ... $119.00 Pi 2, 12" Green $119.00 For1250 $129.00 HP 1 1 C $69.00 Mark VIII (1200 Baud) $269.00 CE 152 Cassette Recorder...962.00 HP 12C $92.00 Pi 3, 12" Amber 5159.00 TRS -80 Color Computer $99.00 Pi 4. 5139.00 CE 155 8K Ram $94.00 HP 15C $92.00 9" Amber 9 Volt Power Supply $9 00 1400C 14" Color $299 00 CE 158 8K Ram Battery ....$129.00 HP 16C $92.00

receive ordEr WESt mailorders East computEro risk. no deposit on C.O.D. orders. Prepaid free shipping within the UPS continental United States with no waning period for certified checks or money orders. Add 3°0(mrntmum 53.00)shipping and handling on all C.O.D. orders 800-648-33 I I PA 800-233-8950 Larger shipments may require additional charges. NV and Dept. 807 Dept. 807 residents add sales tax. All items subject to availability and price change. NOTE: We stock manufacturers and third party In NV call (702)588-5654 In PA call (717)327)9575 the market. Call today for software for most all computers on P.O. Box 6689. Stateline. NV 89449 477 E. 3rd St.. Williamsport. PA 17701 our new catalog. CIRCLE NO. 11 ON FREE INFORMATION CARD

www.americanradiohistory.comAmericanRadioHistory.Com carbon ribbon against paper tc make the directly from the computer's keyboard Guidelines to printed impression. or from software.) And, as in typewrit- Should you wish to produce hun- ers, the elements that actually strike Buying Impact-Type dreds of letters, making them appear as characters on paper are on metal or Printers if a secretary had typed each one indi- plastic "slugs" affixed to the ends of

vidually, then a letter -quality printer is springy lever arms. In ' all, the daisy By Al Burawa the way to go. The price you pay for this wheel has 96 slug /arm assemblies that is higher cost and lower speed than dot - radiate from a central hub, enough for IT'S not surprising that a printer often matrix printers -plus giving ap special the entire upper- and lower -case alpha - heads one's .ist of most cesirable com- graphics. betic, numeric, punctuation, and special puter peripherals. After all, most people Formed- letter printers sucn as Dia- ASCII character set. want hard copies of their work. blo, Qume, NEC, and similar models An alternative to the daisy wheel is For mcst applications, -he choice of a could have a suggested retail p-ice in the the print "thimble" element used in printer comes down to an impact type neightorhood of $2500; though others, NEC Personal Computer Division's rather than a thermal, ink jet or other such as Smith -Corona's model is below popular "Spinwriter" series of printers. form of nonimpact design. So we will fo- the $1000 mark. Substantial discounts Character slugs are arranged on the cus here pn this most popular class of are commonly offerred, thougt. In con- thimble's lever arms in much the same printers, which has two categories: trast, the low end of impact dot- matrix manner as on the daisy wheel, except fully -formed- character printers and im- printers is around $250. For typesetting that there are :wo characters per slug, pact dot -matrix printers. speed, formed -character printers gener- one above the tither. The lever arms are ally range from about 12 cps (characters 'folded" so that the entire assembly Letter -Quality Printers. If you want per second) to 60 cps, whereas dot -ma- :akes on the shape of a thimble. Alter - print quality that is indistinguishable trix printers usually operate at speeds nate characters on each slug /arm as- from that of a typewriter's characters, from 50 to 200 cps. sembly are accessed by a shift command the popular daisy -wheel printer will Formed- character printers provide similar to that ased in typewriters. likely come to mind, even though there sharp, continuous characters, like those To our knowledge, all print thimbles are other methods used to achieve a sim- you're now reading, in a varie-y of sizes are made of highly durable plastic that's ilar goal. The daisy wheel is simply a flat and fonts (styles). The actual print ele- capable of delivering a useful life of sev- wheel with individual -character spokes ment is very similar to that found in the eral tens of millions of print impres- attached to _t. When a key on a key- standard office typewriter. In fact, a sions. Daisy -wheel print elements can board is pressed, it causes the wheel to formed -character computer printer can be made of either metal or plastic, the rotate to the spoke that has the selected be thorght of as an electric t,'pewriter -a-Aer with about the same useful life as letter or number, and a hammer strikes minus keyboard. (Printing commands or the thimble. Metal daisy wheels, the spoke so that the character hits a are generated by the computer, either costing several :imes more than plastic

August l'IR,i

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units, are designed mainly for highly in- faces. The fonts can even be mixed in a to permit settling. Only then can the tensive use, where they'll be in opera- single letter or document, though the hammer be activated to make the char- tion the entire business day. procedure can be time- consuming, since acter impression. This entire procedure Although the formed -character each change requires that the print- must be repeated for each character to printer isn't capable of providing the wheel or thimble be changed. be printed. Without the pauses between graphics capability available with even Being able to change pitch and font is strikes, printed characters would smear, the lowest -level dot -matrix printer, it only part of the flexibility picture for and the print element itself might be has one very appealing advantage. That formed -character printers. Using other damaged. iF the ability to provide an almost un- options, available with hardware and/ Every pause to strike a character slug limited variety of sizes and styles of type or software, you can give a report or let- consumes time that reduces printing simply by changing from print element ter a professional printed appearance, speed. The length of each pause is a to print element. The variety is limited especially when variable pitch and font function of the momentum of the move- only by what's available in the changes are used in conjunction with ments in the entire printing mechanism marketplace. proportional spacing, left and right as it sweeps horizontally across the pa- Daisy -wheel and thimble formed - margin justification, and proper hyper in its track. More important, much character printers operate in the same phenation. (In proportional spacing, time is consumed by having to rely on manner to strike characters onto paper. characters are assigned only enough only the natural springiness of the print Since they're invariably impact mecha- horizontal space for neat, legible print- element's slug arm and the mass of the nisms, both have their character slugs ing. Lower -case characters i, 1, and 1 are slug/arm assembly to return the charac- struck from behind by a "hammer" that assigned narrower space than such stan- ter slug to its neutral position. forces character impressions onto the dard -width characters as a, b, c, etc., paper through an inked or carbon rib- while the extra -wide M, W, m, and w are Dot -Matrix Printers. In dot -matrix bon as previously cited. In the case of assigned commensurately more space. printing, an entirely different approach the thimble whose alternate character is Additionally, spaces between words can to character formation is used, almost to be struck, a shift operation occurs. be varied to suit the demands of the jus- totally unrelated to that used in the tra- Formed -character printers generally tification and proportional- spacing pa- ditional typewriter and formed- charac- feature full -page -width (80 columns on rameters.) A finished printed docu- ter printer. The only similarity to the 81íz" -wide paper), although many mod- ment, then, could have an appearance formed -character printer is that it els are able to accommodate 14" -wide very similar to the professionally print- strikes characters on paper by impact. paper for printing up to 132 columns ed copy on this page. (There's also a thermal dot -matrix ap- horizontally. Except in the lowest - As a rule, formed- character serial proach that doesn't require impacting.) priced models, selectable pitch is com- printers churn out copy at a much slow- To begin with, there's no multitude of mon. (Pitch defines the number of printer speed than is possible with the typical print slugs used. Instead, the 96 or more able characters per horizontal inch - dot -matrix printer because certain laws printable characters are all produced by pica is 10, elite is 12, and micro is 15 to of physics must be observed. During a wire or needle matrix of so many dots 17 characters per inch.) To obtain dif- printing, whenever a slug is to be struck wide by so many high (5 X 7, 5 X 9, ferent pitches, printwheels or thimbles to print a character, the appropriate 9 X 9, or any other combination). Al- must be interchanged. slug must be spun into position between though the matrix might be specified as With formed -character printers, hammer and ribbon. Then the entire consisting of so many dots wide by so there is a choice among different fonts print mechanism, printwheel plus the many dots high, this doesn't mean that (print styles), including a variety of mechanical hammer /carrier assembly, the actual dot -matrix printhead has 35 standard Roman, italic, and even bold must be brought to a full stop and pause print pins for a 5 X 7 matrix, 45 print pins for a 5 X 9 matrix, etc. Actually, modern dot -matrix printheads have only one or, at most, two vertical col- PLATEN PLATEN umns of print pins. PAPER PAPER As a rule, for a dot -matrix printer, the RIBBON RIBBON fixed matrix for each printable alpha- RIBBON GUIDE betic, numeric, punctuation, special,

J CHARACTER and block graphics character is pro- j/ / SLUG grammed into one or more ROMs resident in the printer. A number of recently introduced dot -matrix printers offer a wide choice of characters, including several international character sets. For ti SOLENOID - ACTIVATED the bit -graphics mode in which each dot HAMMER can be individually selected (instead of SLUG DOT- MATRIX being preprogrammed into a ROM), a -LEVER f ARM PRINT HEAD feature currently exclusive to dot -matrix printers, the vertical element of the DAISYWHEEL matrix is fixed, but any number of dots HUB - can make up the horizontal element, Mechanical arrangement of such as 9 X n, where n can be any num- the daisy -wheel and dot- ber up to the maximum that can be matrix printing elements. printed across the page. Text characters could also be generated in the graphics

72 Computers & Electronics

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www.americanradiohistory.comAmericanRadioHistory.Com COMPUTER PRINTERS mode, but since each would have to be much less ragged in appearance than in mechanism but without most of the constructed as needed, this would be the correspondence- quality mode. At bells and whistles available in more ex- very time -consuming and would require first glance, they could almost be taken pensive printers at relatively low cost. slow single- direction printing. as having been generated by a formed - Bear in mind, however, that the special- Virtually any character, text or character printer, the only immediate ly treated paper for thermal printing graphic, can be generated and printed in giveaway being the unavoidable slight may not be readily available in your a matrix of dots, provided the matrix is raggedness of descenders for the g, y, area and that it's more costly than ordi- large enough. In a 9 X 7 matrix, for ex- and j. As it's improved, this mode will nary paper. probably become acceptable for even A full -size impact -type dot -matrix letter and report writing that have ex- printer is preferable for all- around clusively been the province of formed - data /word processing and printing of character printers. computer graphics. This category has Combining near -letter -quality print- the broadest range of models available, ing with the capability of mixing in at prices from as low as $250 on up to graphics without having to change and beyond $2000. Almost all such printers will further add to the appeal of printers feature the same or similar ba- the dot-matrix printer in the future. Of sic printing mechanism; so how much course, to obtain near- letter -quality you pay for a given model will depend printing, one must sacrifice something. on what you're looking for in terms of In this case, it's printing speed, which speed, versatility, reliability, operating may be as little as 25% of the speed ob- convenience, etc. As a rule, the faster, tainable with the same printer in the more versatile, and convenient a printer data -quality printing mode, since sever- is to operate, the greater its cost. al passes are required to provide the de- A completely different design ap- sired printed dot density. proach and different materials are used Aside from providing different levels in the dot -matrix printing scheme. Con- of legibility, dot -matrix printers offer sequently, many of the constraints im- another feature that greatly adds to posed by formed- character printers are their appeal. That is the ability, under eliminated or dramatically reduced, software control, to change pitch and making it possible for the dot -matrix ample, it's possible to construct the density of the print. Typically, charac- printer to operate at much faster print- standard ASCII character set in upper - ters can be printed out condensed, nor- ing speeds than is possible with the typi- and lower -case Roman and italic char- mal, and expanded, representing three cal formed- character printer. acters as well as superscripts and sub- different pitches. Furthermore, in all scripts and underlining. Additionally, three pitches, they can be double - SINGLE CHARACTER by controlling other parameters during struck, emphasized, or emphasized CARRIERS capa- printing, one can obtain different levels double- struck. Depending on the TWO -CHARACTER of legibility quality. bilities built into any given printer, you CARRIERS Data -quality printing is the least legi- can have at your command a range of ble, revealing gaps between the dots. fonts/sizes /densities for type that can't However, data- quality printing is still be matched by any typewriter and few, extensively used in noncritical applica- if any, formed- character printers. Not tions because its basic advantage is its all dot-matrix printers currently on the DAISYWHEEL NEC THIMBLE high -speed throughput. market offer this full range of facilities, ELEMENT ELEMENT Moving up in legibility, we come to of course. And even among those that A so- called "correspondence" quality dot - do, one might offer these standard, Formed- character printing elements. matrix printing. Here we find each while another might provide them as ex- character is more or less continuous, tra -cost options. To begin with, there are no spinning with no gaps between the dots. Corre- With dot-matrix printers, you have a character slugs in the dot -matrix print- spondence- quality characters have an much wider variety of types and models er. Therefore, the only positioning mo- unfinished, slightly ragged appearance, from which to choose. For a minimal in- tion is the horizontal sweep of the print though they're a vast improvement over vestment of, say, $100 or less, you can head across the paper. Pauses occur data-quality characters. To obtain this choose a partial- page -width (20 to 40 only when a carriage- return/line -feed level of quality, each character is struck columns horizontally) nonimpact ther- or line -feed-only operation is encoun- more than once (usually twice to fill in mal printer. This miniature model is an tered in the drive data coming from the the gaps) as the printhead sweeps across excellent companion for the compact computer during the uninterrupted the paper. Consequently, printing in battery- operated portable computer sweep. Very small and lightweight pins correspondence quality is slower than and, in some applications, for a desktop in the printhead are selectively "fired" for data- quality printing by as much as computer. However, if you plan to use and withdrawn at lightning speed to 50 %. your system for word processing or oth- form letters. Even though the printhead For maximum legibility, some of the er serious applications, a full -page- is in motion, therefore, there's no time latest dot -matrix printer models feature width printer capable of printing 80 to for the dots to smear as they're being a mode called "near- letter -quality" 132 columns would be a much more printed. (NLQ) printing. As the name implies, practical choice. Elimination of a spinning print ele- characters generated in this mode are Full-page -width dot -matrix printers ment and pausing for settling time and generally continuous and therefore can be obtained with a thermal printing striking, plus the fact that the print pins

74 Computers & Electronics

www.americanradiohistory.comAmericanRadioHistory.Com are power fired and retracted, make it PRINTHEAD PRINTHEAD possible for the dot -matrix printer to SINGLE TWO operate at speeds up to 400 cps in the COLUMN COLUMN most expensive models. For moderately priced printers, speed is more like 100 to 200 cps, which is two or more times fast- 0000 er than that available with very expensive formed- character printers. Even low -end economy- priced dot -matrix 0000 printers offer speeds in a range between 60 to 150 cps. The speed specification for a dot -ma- 00}00 trix printer can be misleading. Virtually all dot -matrix printers that have been DATA -QUALITY CORRESPONDENCE CHARACTER. OR- NEAR - LETTER- introduced into the marketplace during NOTE GAPS QUALITY. BETWEEN DOTS. NOTE ABSENCE the past few years are designed to oper- SINGLE -PASS OF GAPS. ate at two or three speeds, depending on PRINTING TWO -PASS PRINTING the print function activated. The fastest How better quality is obtained in dot matrix by two passes. specified printing speed is for standard single -pass "data- quality" printing, in which dots are printed with blank space More recently, so-called "near- letter- two separate columns of print pins that between the dots. quality" printing, in which printed permit high -density -dot printing in the So- called "correspondence -quality" characters have a more finished appear- two -pass mode, only halving the speed printing, introduced a few years ago to ance, has been introduced. This level of obtained with data -quality printing. improve legibility, is achieved with two - printing quality can be achieved in ei- Other factors govern how fast a print- pass (sometimes called "overstriking ") ther of two ways. In older model printer can operate, too. For example, defeat- printing, which fills the normally blank ers, it is obtained with a multiple-pass ing the bidirectional printing capability, spaces between the dots with more dots technique, each pass reducing the speed now more or less standard in new dot - to form more or less continuous charac- commensurately. For example, if four matrix printer introductions, wastes ters, though actual printed characters passes are required to achieve near -let- time in returning the printhead from the will have a somewhat ragged, unfin- ter- quality printing in a 200 -cps printer, right margin to the left margin. Also, ished appearance. Operating a dot -ma- speed will be only 50 cps. A more effi- you should be aware that printing trix printer in the correspondence -qual- cient technique is used in the newest graphics isn't as fast as alphanumerics, ity mode usually halves the speed. printers, which have printheads with punctuation, and special characters.

5 X 7 7 X 9 9 X12 A TYPICAL CHARACTER MATRICES

PRINTHEAD w w w w w w w w w w w z z A Z z 'O z ,p 01Z z z z r tD z r` r- P sD r` r tp Z ery - I r r r r- I 1 r-! _zz_-O o,.á a_! zzzzulaaa0000 ariááa'-z,-!O -zo0 r r,az0 uiváaz»áá,rizoi_0 o a a !

2 o' 131111111 IIIIIIIIItI111111 1I11I11 I1311 3 o ME OM MUUE EV EMU, IOG wVEMOMM De ,n o iiiiiiíiiiiiiiiiiiiiiiiii iiiiiiiiiiii6 O EEO NOWOO iEOVOOEMOOMEOVOM'011104MOVEM 017 ó uM 9 PRINTHEAD TRAVEL Y PRINTING COLUMNS PINS B MDot-matrix printhead has a single vertical column of printing pins that are selectively "fired."

August1983 75

www.americanradiohistory.comAmericanRadioHistory.Com COMPUTER PRINTERS

Most dot -matrix printers operated in study of what's available in the market- swer "light" if your printing needs are the graphics mode are slower than in the place. If your major or exclusive use of infrequent and usually limited to 10 text mode because printing is in only the printer is for generating mailable pages or less per session. For strictly one direction. There are a few excep- letters and /or professional -quality nonprofessional home use, figure your tions to this, of course. For example, printing, plan on a letter -quality printing volume to be light. Answer Centronics recently introduced a line of formed -character printer. However, if "moderate" for normal daily business dot -matrix printers capable of printing you require fast printing speed, such as office use in which 100 to, say, 300 let- graphics bidirectionally.) for regularly typing hundreds or thou- ters, memos, and envelopes are to be The cost of a printer is directly relat- sands of mailing labels at one time, or printed daily. Answer "heavy" for more out of ed to the number of precision mechani- you must keep hard copies of account- intensive use, as in daily printing and in cal parts that go into its design. Oddly, ing and financial records, or you wish to large volumes of mailing labels will the very complex electronic portions of print out graphics, etc., your better word processing, where the printer printers are dirt cheap when compared choice would be a dot -matrix printer. be going for 35% or more of the time in to the high -precision metal and plastic For strictly home use, the dot -matrix an eight -hour day. elements. This accounts for the much printer is perhaps best because of its rel- 3) What printing speed do I need? higher demand for formed -character atively low cost, versatility, and suffi- For occasional light printing volume, printers, which have a much higher pre- cient print quality for general use. any printer capable of churning out cision -parts count than is required in Let's detail the important factors you copy at even the slowest speeds will suf- the dot -matrix printer. Each of the me- must consider when it comes time to fice. For moderate volume, be conserva- chanical elements in the formed- charac- make your buy decision. Make up a tive and note 75 cps or more. For heavy ter printer must be machined to very master list as follows: volume, plan on a minimum of 150 cps. you close tolerances, at a very high cost. 1) Do I need letter -quality printing 4) Do I need variable pitch? If contrast, the dot-matrix printer is or will data- or correspondence -quality do, don't think you must spring for an In printer. a relatively simple mechanical but com- printing suffice? If your needs are exclu- expensive formed -character plex electrical device. Its relatively few sively for letter and report writing, plan Most dot -matrix printers offer selecta- precision mechanical parts are con- on a formed -character printer; other- ble expanded, normal, and condensed having to change tained in the printhead and linear head - wise, specify a dot -matrix printer. Bear characters, without positioning /track assembly. Consider- in mind the differences in print quality the printhead. This feature will fre- ing that a much greater number of obtainable at different price levels. If quently be enough to fill your printing mechanical elements are used in the you need high -quality legibility, note needs. Also, some of the new computers graphics ca- typical printing assembly of a formed - this alongside your dot -matrix entry. that feature bit -addressable character printer than there are in an Remember, too, that a number of re- pability will allow you to custom design entire dot -matrix printer, it's not diffi- cently introduced dot -matrix printers and program in one or more user -call- cult to understand why the latter is so are capable of generating near- letter- able character sets on a compressed or much less expensive. quality printed characters that will al- expanded matrix format. most always suffice for the high -quality 5) Do I need proportional- spacing nicety Selecting a Printer. Your choice of a copy required for letter /report writing capability? Although this is a particular make and model printer in which a true professional appearance that most users will instinctively desire, should be based on an intelligent study isn't essential. it's not essential, except in such rare ap- of your current and future needs and a 2) What is my printing volume? An- plications as publishing, fancy corpo- rate report drafting, and other professional printing applications. Almost all formed -character and a few newly in- printers offer this I !NJ r)DLJL-c1_EW I 1C3T1-1 troduced dot -matrix capability. Those printers that do usual- I doublestrike. ly include it at little or no extra cost. in attractive pro - :an be printed an 6) Do I need superscript and sub- pular PICA type. script capability? The same remarks given for 5) above apply here, except graphics in the same that those who need this feature will international usually be mathematicians, scientists, engineers, and publishers and report writers. 7) What kind of paper feed do I need? If you're going to be printing ex- After easily setting the proper values clusively on pin -feed fan -fold printer single page letters or multi -page paper, ordinary pin -feed will do. But if on into the printer and then collated you're going to be printing mainly without single sheets (called "cut -sheet paper "), quence continues automatically your choice of printer should have fric- paper -out switch activates or a manua tion feed. For most reliable printing on ual insertion is possible at any time all types of paper, including envelopes and mailing labels, a combination is In At top are print samples from an Epson FX printer. friction /tractor (F /T) feed best. Below is a near- letter- quality sample from a Centronics Model 353. the past, this was an option that had to be added to the basic printer, usually at

Computers & Electronics 76

www.americanradiohistory.comAmericanRadioHistory.Com high cost. However, more and more few months, socking away a few extra RAM buffer memory to store incoming printer manufacturers are beginning to bucks until you have enough to buy the data that's being received too fast for offer friction /tractor feed as a basic part model that best suits your needs, than to the printer to handle. Buffer memory of their products at no extra cost. make a hasty purchase that won't satis- can be expanded, of course, either by an 8) Do I need graphics capability? If fy you. external printer buffer or, in some cases, your answer to this question is "yes," For the business office, keep in mind with an internal board, if you regularly plan on restricting your choice to the that it's not necessary to buy a printer dump a lot of copy from the computer dot -matrix printer category. Be aware for each computing station, since it's a to the printer. that not all dot -matrix printers are ca- rarity for every station to require print- All printers aren't alike, though most pable of printing out everything that outs at the same time. In fact, under or- share many similar features. For exam- can be displayed on a computer's video dinary data- and word -processing cir- ple, low -cost impact dot -matrix printers display screen on a dot-for -dot basis. cumstances, a printer will be idle more often feature 5 X 7 dot matrix. If it has a Some printers are able to print only the than 75% of the time! Therefore, you lower -case facility, the letters won't "block" graphics characters contained can plan your printer purchases with produce true descenders, so that the in preprogrammed ROMs inside the station sharing in mind. You have two bottom of, say, the letter "g" will be in printers. Unless a manufacturer speci- choices here. The simpler choice is to reline with the bottom part of, say, the let- fies that his product can print dot -ad- serve one of the several stations for basi- ter "b." Perhaps this is good enough for dressable graphics, assume it can't. cally print -only operations. The alter- you, given the savings in money, but you 9) Do I need alternate character sets? should know what you're going to get in This question applies exclusively to dot - return. matrix printers, since all formed -char- Is the paper drive a friction or tractor acter printers by nature of their inter- Aa Gg Mm Zz type? The former uses roll paper that's changeable printwheels or thimbles are less costly, while the latter will enable inherently capable of alternate charac- you to print accurately and automati- ter set selection. With dot- matrix print- cally on a given sheet of fan -fold paper ers, one doesn't pop out one head and or on mailing labels. Some printers Formed -matrix replace it with another to obtain a dif- and dot letters. come with both facilities at no addition- ferent character set. Alternate character al charge. fonts must be obtained with the existing native is to have two or more computing Among other considerations are: the matrix head, using software, which may stations share one printer, without hav- paper width the printer can handle, be in preprogrammed ROMs inside the ing to install special-and expen- number of copies it can make, paper machines themselves. Some of the sive- multiple -user hardware and soft- "out" alarm, addressable tabbing, over- newest dot -matrix printers on the mar- ware. This latter approach is imple- all dimensions, compressed and ex- ket come standard with up to eight dif- mented by installing an optional switch- panded print, and dot -addressable ferent character sets that can be selec- ing box between the printer and sharing graphics provisions. tively switched in and out as desired. stations. Most such switching accesso- No matter how sophisticated a print- Others have on -board sockets into ries offer print buffers, standard or oper you decide to buy, you'll need the which optional character -set ROMs can tionally, to ensure efficient word /data proper software to take advantage of its be plugged and called at will from processing. specific features. In fact, if you're software. With the first approach, the comput- putting together a sophisticated word - 10) How much should I pay? This er /printer station might be idle for long processing system, review your needs question usually tops the uninformed periods of time. The second approach is with an eye to both printer and driving prospective buyer's list. In practical more practical because all stations can software. terms, it should be way down on the list, be active simultaneously for processing, If you select a printer that offers true as it is here, because the answer will be and there's no need to have operator underlining, superscripting and sub - based on the answers to all the preced- shuffling from one station to another. scripting, proportional spacing, etc., ca- ing questions. It would be extremely pabilities, get a software package that foolhardy -and expensive -to let bud- Other Considerations. Printers con- will allow you to access these features. getary considerations overshadow your nect into a computer in either of two Don't forget that any feature you add to needs. Don't plunge in and choose an ways: parallel (Centronics) or serial a basic printer or package will add to its inexpensive printer that isn't capable of feed (RS232C). In most cases, the paral- cost, however; so plan your purchases meeting all your current needs, much lel interface is built into the printer, accordingly. If you buy more printer less leave room for growth, or an expen- while the serial interface electronics is than you need, you'll be throwing away sive full- featured printer with features optional even though the printer has a money that can be better spent on some- you'll never use. Such a move will prove plug -in facility on the back marked ac- thing else you might want or need for costly in the long run, since it won't be cordingly. Perversely, most computers your system. long before you have to trade up any- come with a serial port, but require an Good high -level word -processing way. By the same token, buying a very optional parallel port to be added. Ac- packages, such as Word Star and Magic fast full- featured printer with lots of cordingly, the user will often have to Wand, will almost always permit you to bells and whistles you'll never use will spend extra money to get his printer up take advantage of virtually every feature prove costly right at the dealer's and running. Bit -parallel interfaces built into modern printers. Basic low - counter. transfer data a word at a time, while bit - cost packages, however, may not. Be- The best advice we can give for choos- serial runs bits one character at a time. fore you buy a software package for ing a printer is: Select what you need. If Consequently, a parallel- interface setup your computer /printer system, careful- you require a model that's too costly for is a speedier one. ly study its description to determine if it your present budget, it's better to wait a Most printers contain 1K to 2K of fills your needs. The several hundred

August1983 77

www.americanradiohistory.comAmericanRadioHistory.Com ...COMPUTER PRINTERS

PRINTER operations are light years slower than any computer's flow of data. Microbuffer II So when a computer is spitting out large amounts of data to a typical dot -matrix Printer Interface for Apple II or daisy-wheel printer, you're forced to wait until everything is printed before By Alexander Marx you can work at the console again. What a waste of time for both you and a sporadically idling CPU! What's the solution? It's simple: take some memory, an inexpensive microprocessor, some support logic, and make the whole thing look like a fast printer to the computer. The computer can now dump the data to this external memory at 4000 plus cps (characters per second) and the additional microprocessor can then send them to the printer at the slower rate. Put the whole thing in a box and you have yourself a printer buffer! The clever people at Practical Peri- pherals (31245 La Baya Drive, West- lake Village, CA 91362) have done just that, and they have a line of buffers to fill every need. For the Apple II computer they have come up with the Microbuffer II, which at $259 comes with 16K of onboard memory that is user -expandable to 32K. It also has an onboard microprocessor and an EPROM that contains the software to handle the buffering as well as some rather clever features. The whole thing is a plug -in card about twice as long as a normal Apple printer card. The card tested was for a parallel "Centronics" interface. Even though it is a parallel interface it looks like a serial interface to the Apple. This is to maintain compatibility with both Pascal and CP /M. The card is installed like a normal Apple card. I placed it in slot 1 (although it can be used in any slot except 0). The card has a detachable cable with the standard parallel connector on one end and a standard Apple multipin connector on the other. The card is transparent in operation if you don't want to do anything fancy. You notice the difference that the buffer makes right away: a standard screen full of data loads into the card in about two seconds as opposed to about a minute without the buffer. The card responds to the conventional commands. These

dollars asked for the software to provide your requirements. Such packages are only $249.95. Models that have been professional printing capabilities will be usually sold at considerable savings around for a while are being sold with well worth the investment since, in the over individual items. considerable discounts. An Epson MX- long run, it can actually save you money Finally, like so much computer hard- 80, the machine that brought logic -seek- in more efficient and flexible processing. ware, printer prices appear to be at an ing to moderately priced printers, can Conversely, if you don't need all the so- all -time low. Leading Edge's "Gorilla/ be bought for less than $500, while phistication built into professional - Banana" impact dot -matrix printer, for Smith- Corona's TP -1 letter -quality dai- grade software, find a package that suits example, has a suggested retail price of sy -wheel printer is being sold for below

78 Computers & Electronics

www.americanradiohistory.comAmericanRadioHistory.Com are prefixed by sending a Control I gramming or would like to follow some- else, some offer bells and whistles but [CHR$(9) in BASIC], followed by one one else's work. It takes a little time to are not compatible with anything. or more parameters. For example, to go get used to the format but, once you do, The Microbuffer II offers the cake from printing 40 to 80 columns, you it makes life a lot easier. and the icing, too. In fact, I used the would first turn the card on with the Another useful command is a screen card for a long time as a straight buffer normal PR# 1 and then enter a Control dump. This will dump the 40- column without having to modify any of my I followed by an 80N. Apple text screen to the printer. You programs. I was oblivious to the other With 16K of memory, you can dump can print the whole screen or specify a wonderful features. Now I use it more about 11 pages of text to the buffer. If starting line, in which case it will print extensively, especially for formatting you upgrade or purchase the 32K ver- from that line to the bottom. The man- BASIC listings, with the left margin set sion, you will double the amount of stor- ual specifies that this command is useful where the text is comfortably centered age. Once the buffer fills up and if you for printing a Visicalc window, but I on the page. No more moving the trac- have more data to send, the system couldn't figure out how to interrupt tor feed to accommodate my word pro - slows down to the normal crawl. As the Visicalc so I could send the command cessor's spacing, while my BASIC list- card sends one line to the printer from code. The manual doesn't elaborate ei- ings are printing on the feed holes! And the bottom of the buffer, a new line from ther. It's a shame that they allude to the graphics dumps are wonderful, con - the computer is entered at the top of the something and yet don't explain at all venient and versatile. buffer. how to achieve the desired effect. There are a few annoying things You may wonder about the use of the The HiRes graphic dump commands about the card, the worst being the man- card at this point since the system is are a nice bonus. They allow you to ual. It is far from complete. It gives you bogged down waiting for the printer, dump HiRes Apple graphics to your enough to get started, but leaves you on just like the old days. But don't forget printer, provided it can handle dot -ad- your own for the rest. I am still trying to that the buffer is still full. At some point dressable graphics. You must specify dump my Visicalc screens because it said the computer will send all the data and what printer you have when you pur- I could, but I am not going to spend an be free once again, while the buffer con- chase the card as each printer requires a hour trying to find out. The other com- tinues to churn out the 16K or 32K that different EPROM. plaint is a lack of a larger technical sec- was filled. It may not be as fast as having The graphic dump commands give tion. It has the standard "for machine unlimited buffer area, but it still saves a you many options including printing language programmers, the following good one -third to one -half of the normal double sized, rotating the image 90 de- information will be useful," but what if I printing time. As I rarely print large grees, inverting the image so black is want to go deeper? For example, what if documents, I get by very nicely with the white and white is black, and empha- I wanted to access the graphic dump 32K. Without reaching the buffer limit, sized so that twice as many dots are routines directly? At least, if you don't you can save close to 90% of your print- printed giving a darker image. The card want to release source code, give entry ing time. will print both the primary HiRes page points or even tips and examples. So much for the "dumb" mode of op- (HGR) or the secondary HiRes page For the dollar, though, I dont' think eration. If the card just buffered the (HGR2). It even allows printing mixed you could do better than this card. The printing it would be well worth the cost. HiRes and Text screen. An additional combination of functions with the rela- But since you have a microprocessor on feature is the Chart Recorder Mode. tive ease of use and compatibility make the card already, you may as well give it This allows two pictures to be printed it unbeatable. some smarts. This card has 25 text for- contiguously, resulting in a larger pic- If you don't have an Apple II, but matting and printer control commands, ture. This can allow for greater detail by would still like buffered printing, one of as well as eight graphics commands for using both of the Apple HiRes screens Practical Peripherals' inline buffers dumping the Apple HiRes graphic and joining them at print time. may be the answer. These buffers go be- screens to the printer. The Microbuffer II is an excellent I ween the computer and printer and di- Some of the text formatting and product. It serves its purpose as a buffer rect the flow from there. They offer sev- printer control commands are: send a simply and elegantly. It follows the eral models in both serial and parallel linefeed after carriage return, set a left standard Apple commands for ease of interface and up to 256K of memory. margin, set the print width, clear the use. It also offers many features not nor- That's about 175 pages of text! There's buffer, and verify the operation of the mally found in a printer card. If you even a model that will fit inside the card (self check). Among the more in- have ever shopped for a printer card, Epson printers. teresting commands is one to format you soon realize that there is too much So, if you are tired of waiting for your BASIC listings so that each one of mul- variety in the marketplace. Some cards printer while you're computing, consid- tiple statements on a line is displayed on offer straight printing with no bells and er a buffer. And if you're considering a its own line, indented from the margin. whistles, some offer buffering, some of- buffer, check out the Practical Peri- This is very useful if you do any pro- fer graphics dump routines and little pherals' line.

$600. And if these are beyond your bud- ever, such as faster printing speed and Riteman's 2743" -high 10" -wide -carriage get, there's still no excuse for not having they are available in most locations, at impact dot -matrix printer that fits into hard copy at your disposal because you surprisingly moderate prices. an attache case, and Max and Mannes- can go the thermal printer route, such as Some unusual concepts are around, mann Tally's battleship- construction with Star Micronics' new STX-80 80- too. These include, among others, impact dot -matrix machines that allows column printer for under $200 suggest- Qume's "personality" modules for its one to set up a variety of characteristics ed retail. Moreover, new models are daisy -wheel printers that simplify mat- from its front panel and store it in non- available that boast more features than ing it with the most popular computers, volatile memory.

August1983 79

www.americanradiohistory.comAmericanRadioHistory.Com PART 4

This series of articles is condensed from a forthcoming book, Soul of CP/M, * by Mitchell Waite and Robert Lafore

SINCE beginning this series, we've been ways, subroutines that drive them must can actually communicate with physi- working our way deeper and deeper into be different for each piece of this equip- cal devices. what we call the "soul" of CP /M -the ment. This collection of the subroutines Now that you know where BIOS re- hidden part not usually visible to the ca- is what constitutes the BIOS. Each of sides and what it does, let's explore how sual user of this operating system. Now these driver subroutines "drives" a par- to modify a driver routine so that your we're going to penetrate to the most hid- ticular peripheral device. When you CP /M can operate with a different den part of CP /M, the BIOS (Basic change from one kind of printer to an- printer. The techniques involved will Input/Output System)! You could call other, you must modify the printer driv- also work for adding or changing other BIOS the innermost soul of CP /M. er in BIOS to be able to "speak" to the peripherals. Changes to the disk drives new printer. are considerably more complicated and What is the BIOS? For BDOS to be Although the BIOS is at the inner- should probably be left to the dealer un- able to execute its duties, it must at most core in CP /M (Fig. 17), it has a di- less you're a very ambitious (experi- some point communicate with the actu- rect connection with the outside world. enced) programmer. al physical devices (disk drives, video In fact, it's the only part of CP /M that Because every system uses different screen, keyboard, printer, etc.) connect-

ed to the computer. Since these *Copyright © 1983 The Waite Group, Inc. All rights reserved. To be published in 1983 peripherals can be from a variety of by Howard W. Sams & Co., 4300 W. 62 St., Indianapolis, IN 46206. manufacturers and operate in different Cat. No. 22030. Reproduced with permission of the publisher.

80 Computers & Electronics

www.americanradiohistory.comAmericanRadioHistory.Com If you own a Timex Sinciair, a ZX81, Storing Three -Letter Words in an or any other Sinclair computer, Array SAVE UP TO 33% you've probably discovered that Software Review: ZX Galaxians the big microcomputer magazines An Introduction to Expression Eval- ON SYNC! cover only the bigger computers. uation Where can you find helpful articles on Short Programs Just for Fun the Sinclair? In Sync! The ZX81 Parser and User -Defined CN 1986 Morristown, NJ 07960 Sync is the one magazine that's Commands written about Clive Sin - exclusively Understanding Floating Point Arith- lease send me marvelous inventions, the Sin- clair's metic YES! PSync for: clair computers. And its the one Handling Strings from Another Di- One year (6 issues) for $12.97- magazine to read if you want to get I mension save 19%. more from your Sinclair. issues) for $22.97- Book Review: Understanding Your Two years (12 You'll find program listings for I save 28 %. ZX81 ROM games, helpful programming tech- Three years (18 issues) for Your niques, hardware upgrades, math and How to Add a Keyboard to Sin- $31.97 -I save 33 %. clair science programs, news of new prod- Savings based on full 1 -year subscription price ucts for the Sinclair -in short, every- Translating Other Basics: DEF on of $16. thing you need to use and enjoy your the ZX81 Mr. Six Outer Space Games Pro- Mrs. Sinclair to the fullest. -With Ms In just two recent issues, for exam- gram Listings (please print full name) 8H15 ple, we covered: Hardware Review: Sinclair ZX Spec- Address Apt Putting a Reverse Character in a trum High Resolution Color /Sound String Computer City Memory If you own a Sinclair microcom- How to Double Your lip Least Squares Data Analysis With puter, Sync is the only computer mag- State the ZX80/81 azine you really need. Subscribe now CHECK ONE: Payment enclosed. Bill me later. Space Warp: A Graphics Space to Sync, and you can save up to 33 %! Offer valid in U.S. and possessions only. Please allow Game Just complete and return the post- 60 to 90 days for delivery of first issue. How to Reduce ''Blank Screen age -paid reply card or the coupon NEW SUBSCRIBERS ONLY J Time" at right.

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The magazi ie for Sinclair and Timex Sinclair users sync FOR Math and Science: Least Squares Analysis Programming: SINCLAIR Alternative Display Storing Words Space Warp Graphics Game AND TIMEX en 9 O PLOT NPLOT REM RANO RETURN IF 1NPU` F KE PRINT 0a RS P SIN DDS TAN INT RN® STRS CHAS CO T/9 SINCLAIR NEW SAVE DIM FOR' GOTO GOäUA LOAO LIST LET D AR AN SONN A SO VAL L USA ® ARC9N f a © LIRE.. C V CLEAR COST CLS SCROLL NF PAUSE OWNERS B 1® . ©EXP AT IN KEYS NOT rn ONLY August 1983 81

www.americanradiohistory.comAmericanRadioHistory.Com .. CPí

hardware, every BIOS will be different. What You Need. There are two things We can't, therefore, tell you exactly how you need before you can modify your to modify your specific BIOS, but we BIOS. The first is the ASM file of the can show you an example that can be BIOS, usually supplied with CP /M, used as a guide for modifying your which contains the 8080 code that com- BIOS to suit your system's needs. municates with I/O devices. This file is There are three steps involved in writ- usually called something like ing a new BIOS driver: (1) learning your IOBIOS.ASM, GBBIOS.ASM, or some way around BIOS -you must be able to similar name with BIOS in it. If the file find the existing driver so you can see contains the I/O for the disk system, it what it looks like, how it relates to the will be very long -20 or more printed I, If this section is left out, the DIRECT rest of BIOS, and where to put the new pages. CONNECTION driver; (2) writing the new driver rou- printout will be fairly short -six pages TO I/O DEVICES tine and then testing it; (3) inserting the or so. new driver into the BIOS file and writ- The BIOS.ASM file is what you're Fig. 17. BIOS, at the real center ing the new BIOS to the system tracks of going to modify, using a word- process- of CP /M, still connects to the world. your disk. ing program to alter a section of it.

;TITLE ,- + BIOS FOR D10 WITH CP /M 2.2 Rev2.7 + + CONSOLE STATUS - CON: CONSTIO: BIOS FOR IMSAI DI 0-C CONTROLLER WITH CP /M 2.2 DE88 CD8FDE CALL CONS ;GETS STAT OF SPECIFIC DEVICE DERB C8 RZ IF NOT READY RETURN 0 IN A BIOS VERSION 2.7:SINGLE DENSITY, 128 B/S DE8C 3EFF MVI A,OFFH ;ELSE RETURN FF DOUBLE DENSITY, 256 B/S DE8E C9 RET ;Z FLAG SET CORRESPONDINGLY DOUBLE DENSITY, 1024 B/S DE8F CDE3DE CONS: CALL DISPATCH 0000 = FALSE EQU 0 DE92 01 DB 1 USE IOBYTE BITS 1.0 FFFF = TRUE EQU NOT FALSE DE93 45DF DW CRTSTAT ;00 - TTY: (CRT STATUS) 0038 = MSIZE EQU 56 ;MEMORY SIZE IN K -BYTES DE95 450F DW CRTSTAT ;01 - CRT: 0036 = SSIZE EOU MSIZE -2 ;2K FOR CP /M,BIOS AND BUFF DE97 45DF DW CRTSTAT ;10 - BAT: 0018 = REVNUM EOU 27 ;BIOS REV # DE99 5FDF DW IKBSTAT ;11 - UC1: (IKB1 STATUS) 0016 = CPMREV EQU 22 ;CP /M REV # "BIAS" IS ADDRESS OFFSET FROM 3400H FOR MEMORY CONSOLE IN - CON: SYSTEMS OTHER THAN 16K (REFERRED TO AS "B" CONINIO: THROUGHOUT THE TEXT). DE9B CDE3DE CALL DISPATCH 8800 = BIAS EOU (SSIZE- 20)1024 ;ADDR OFFSET FROM DE9E 01 DB 1 ;USE IOBYTE BITS 1.0 3400 (20K SYSTEM) DE9F 4ADF DW CRTIN ;00 -TTY: (CRT INPUT) BC00 = CCP EQU 3400H +BIAS ;BASE OF CCP DEA1 4ADF DW CRTIN ;01 - CRT: C406 = BDOS EOU CCP +806H ;BASE OF BDOS DEA3 4ADF DW CRTIN ;10 BAT: - INPUT) D200 = BIOS EQU CCP +1600H ;BASE OF BIOS DEA5 640F DW IKBIN ;11 UC1: (IKB1 I/O DEFINITION EQUATES CONSOLE OUT - CON: CONOUTIO: USEFUL THINGS TO KNOW DEA7 CDE3DE CALL DISPATCH MPU -B STATUS PORT DEAA 01 DB 1 USE IOBYTE BITS 1.0 /TRANSMITTER REFERENCE) (TERMINAL DEAB 55DF DW CRTOUT ;00 - TTY: (CRT OUTPUT) DEAD 55DF DW CRTOUT ;01 - CRT: (CRT OUTPUT) 0 = TxRDY TRANSMITTER READY DEAF 55DF DW CRTOUT ;10 - BAT: (CRT OUTPUT) 1 = RxRDY RECEIVER READY DEBI 6FDF DW VIOOUT ;11 - UC1: (VIO OUTPUT) 2 = TxE TRANSMITTER EMPTY 3 = PE PARITY ERROR LIST STATUS - LST: 4=0E OVERRUN ERROR LISTSTIO: 5 = FE FRAMING ERROR DEB3 CDE3DE CALL DISPATCH 8 = SYNDET SYNC DETECT DEBE 03 DB 3 USE IOBYTE BITS 7.6 7 = DSR DATA SET READY DEB7 42DF DW LISTSTC ;00 - TTY: (CRT OUTPUT) OEB9 42DF DW LISTSTC ;01 - CRT: (CRT OUTPUT) ;CONSOLE STATUS PORT (IN HEX) 15 = PARALLEL DEBB 42DF DW LISTSTC ;10 - LPT: (LINE PTR 13 OR 4 = SERIAL OUTPUT) 3 = SYSTEM DEBD 42DF DW LISTSTC ;11 - UL1: (VIO OUTPUT) ;CONSOLE DATA PORT (IN HEX) 14 = PARALLEL 12 OR 4 = SERIAL LIST OUT LST: 2 = SYSTEM LISTIO: DEBF CDE3DE CALL DISPATCH 0003 = CRTST EOU 3H ;CRT STATUS PORT DEC2 03 DB 3 USE IOBYTE BITS 7.8 0002 = CRTDATA EQU 2H ;CRT DATA PORT DEC3 55DF DW CRTOUT ;00 - TTY: (CRT OUTPUT) 0015 = IKBST EQU 15H ;IKB1 STATUS PORT DEC5 55DF DW CRTOUT ;01 - CRT: (CRT OUTPUT) 0014 = IKBDATA EOU 14H ;IKB1 DATA PORT DEC7 35DF DW LPTOUT ;10 - LPT: (LINE PTR F803 VIODATA EQU OF803H ;VIO DATA PORT = OUTPUT) 0002 = RXRDY EQU 02H ;CONSOLE STATUS DEB9 6FDF DW VIOOUT ;11 - UL1: (VIDEO READY BIT (RxRDY) OUTPUT) 0003 = IOBYTE EQU 0003H ;INTEL I/O BYTE F800 = VIOINIT EQU OF800H ;VIO INIT ENTRY POINT PUNCH OUT - PUN: FFFD = VIOID EOU OFFFDH ;POINTER TO VIO ID PUNCHIO: 0023 = PRTS EQU 23H ;PRINTER STATUS PORT DECB CDE3DE CALL DISPATCH 0022 = PRT EQU 22H ;PRINTER DATA PORT DECE 05 DB 5 USE IOBYTE BITS 5.4 DECF 55DF OW CRTOUT ;00 TTY: (CRT OUTPUT) I/O DEVICES. USER CUSTOMIZED DED1 73DF DW PUNOUT ;01 - PTP: (H. S. PUNCH TABLE. DO NOT REARRANGE JMP OUTPUT) DED3 6FDF DW VIOOUT ;10 UPI: (VIO OUTPUT) BIOS +OC7OH DE70 ORG DED5 55DF DW CRTOUT ;11 - UP2: (CRT OUTPUT) DE70 C3F8DE INITIO: JMP INITVC DE73 C3BFDE LIST: JMP LISTIO READER IN - RDR: DE76 C3B3DE LISTST: JMP LISTSTIO READERIO: DE79 C388DE CONST: JMP CONSTIO DED7 CDE3DE CALL DISPATCH DE7C C39BDE CONIN: JMP CONINIO DEDA 07 DB 7 USE IOBYTE BITS 3-2 JMP CONOUTIO DE7F C3A7DE CONOUT: DEDB 4ADF DW CRTIN ;00 - TTY: (CRT INPUT) CONOUTIO DE82 C3CBDE PUNCH: JMP DEDD 74DF DW RDRIN ;01 - PTR: (H. S. READER DE85 C3D7DE READER JMP READERIO INPUT) DEDF 4ADF DW CRTIN ;10 - UR1: (CRT INPUT) DEE1 4ADF OW CRTIN ;11 - UR2: (CRT INPUT) Fig. 18. BIOS for DIO with CP /M 2.2, Rev. 2.7.

82 Computers & Electronics

www.americanradiohistory.comAmericanRadioHistory.Com You'll then reassemble it with ASM and possible to modify your BIOS without Fig. 18 is only one example of the hun- write it back onto the system tracks of the actual spec sheet -provided the dreds of possible versions in circulation. your disk. UART is already installed and operat- Yours may be somewhat different, but it The second thing you'll need is the ing and your listing has this informa- should be similar enough that you can specifications table for your UART tion. It's also easier if you have a device follow in your BIOS the steps we'll de- (universal asynchronous receiver/ already operating which is similar to the scribe here. Reading your BIOS listing transmitter) or serial I/O board. The one you plan to install. will make the most sense if you assemble UART IC is installed on the serial If you already have a printer running it with ASM and then refer to the PRN board and allows the computer to com- and want to change to another printer, listing, since often the hex values given municate in serial mode with external you may not need the spec sheet or com- are important. devices. The spec sheet for the UART ments in the listing. You can use the ex- will tell you what numbers to output to isting driver as a model. Of course, if BIOS Introduces Itself. When called what "port" in the UART to send sig- you don't have a printer, you'll need the from disk, BIOS introduces itself, as nals to various I/O devices. spec sheet. shown in the beginning of the BIOS list- Some versions of the BIOS.ASM file ing in Fig. 18. BIOS starts out by de- include information on the UART at Sample BIOS. Bear in mind that the scribing itself, where it comes from, and the beginning of the listing, making it particular BIOS we'll be describing in what it's for. Our example comes from

DISPATCH DEE3 E3 XTHL ;SAVE CALLER'S H, GET RETURN LIST STATUS (FF IF READY, ELSE 0) TABLE ADD DEE4 56 MOV D,M ;SHIFT COUNT DF42 3EFF LISTSTC: MVI A,OFFH DEE5 23 INX H ;POINT TABLE DF44 C9 RET DEE6 3A0300 LDA IOBYTE ;GET 10 ASSIGNMENTS BYTE CONSOLE STATUS RETURNED IN A. DEE9 07 DSHFT: RLC DEEA 15 DCR D CRTSTAT: DEER C2E9DE JNZ DSHFT ;SHIFT TO POSITION DF45 DB03 IN CRTST ;STATUS PORT BITS DF47 E802 ANI RXRDY ;TEST RxRDY DEEE E606 ANI 06H ;MASK BITS DF49 C9 RET Z =1, CHAR NOT DEFO 5F MOV E,A ;D ALREADY CLEAR READY DEF1 19 DAD D ;INDEX INTO TABLE DEF2 7E MOV A,M CONSOLE IN RETURNS THE CHARACTER IN A DEF3 23 INX H ;TABLE WORD TO HL DEF4 66 MOV H,M CRTIN DEF5 6F MOV L,A DF4A CO45DF CALL CRTSTAT DEF6 E3 XTHL ;PUT ADDR OF ROUTINE, GET CALLER'S DF4D CA4ADF JZ CRTIN ;GET RxRDY H DF50 DB02 IN CRTDATA ;GET CHAR DEF7 C9 RET ;GO TO ROUTINE DF52 E67F ANI 7FH STRIP PARITY DF54 C9 RET

INIT USER 1/01E. CONSOLE ,PUNCH AND LIST DEV. CRTOUT SENDS THE CHARACTER IN C TO OUTPUT

INITVC: CRTOUT: INIT UART (RECOMMENDED CMDS BY IMSAI) DF55 DB03 IN CRTST ;GET STATUS DEFB AF XRA A DF57 OF RRC ; TxRDY? DEF9 D303 OUT CRTST DF58 D255DF JNC CRTOUT ;REPEAT, NOT READY DEFB 0303 OUT CRTST DF5B 79 MOV A,C ;CHAR TO ACCUM DEFD D303 OUT CRTST DF5C D302 OUT CRTDATA :CHAR TO PORT DEFF 0323 OUT PRTS DF5E C9 RET DF01 0323 OUT PRTS DF03 0323 OUT PRTS IKB1 STATUS RETURNED IN A. DF05 3E40 MVI A,40H ;RST 8251 DF07 0303 OUT CRTST IKBSTAT DF09 0323 OUT PRTS DF5F DB15 IN IKBST STATUS PORT DFOB 3EAE MVI A,OAEH ;MODE DF81 E602 ANI RXRDY ;TEST RxRDY DFOD D303 OUT CRTST DF63 C9 RET :Z =1, CHAR NOT DFOF 0323 OUT PRTS READY DF11 3E27 MVI A,27H ;CMD DF13 D303 OUT CRTST IKB1 IN RETURNS THE CHARACTER IN A DF15 0323 OUT PRTS IKBIN: DF64 CDSFDF CALL IKBSTAT DF17 21FDFF LXI H,VIOID ;VIO ID 1 ADDR DF1A 3E56 MVI A,'V' ;1ST ID DF67 CA64DF JZ IKBIN ;GET RxRDY DF1C BE CMP M ;SAME? DF6A DB14 IN IKBDATA ;GET CHAR DF1D C22FDF JNZ NOVIO DF6C E67F ANI 7FH ;STRIP PARITY DF20 23 INX H ;VIO ID 2 ADDR DF6E C9 RET DF21 3E49 MVI A,'i' ;2ND ID DF23 BE CMP M ;SAME? VIOOUT SENDS THE CHARACTER IN C TO VIO DF24 C22FDF JNZ NOVIO DF27 CD00F8 CALL VIOINIT ;INIT VIO VIOOUT: 79 DF2A 3E97 MVI A,97H ;VIO AS OUTPUT DF6F MOV A,C DF2C C331DF iMP INITIOI DF70 C303F8 JMP VIODATA ;VIO RETURNS TO DF2F 3E94 NOVIO: MVI A,94H ;CRT AS OUTPUT CALLER INITIOt: PUNCH CHARACTER IN REGISTER C DF31 320300 STA IOBYTE DF34 C9 RET PUNOUT: DF73 C9 RET ;NULL ROUTINE LIST CHARACTER IN C READ CHARACTER INTO A FROM READER DEVICE DF35 DB23 LPTOUT: IN PRTS ;CHECK STATUS PORT DF37 E885 ANI 85H ;CHECK BOTH READY RDRIN: BITS DF74 3E1A. MVI A,1AH ;ENTER END OF FILE DF39 EE85 XRI 85H (REPLACE LATER) DF3B C235DF JNZ LPTOUT DF76 E67F ANI 7FH :REMEMBER TO DF3E 79 MOV A,C STRIP PARITY BIT DF3F 0322 OUT PRT DF78 C9 RET DF41 C9 RET ;USER PRINTER IO DF79 END

August1983 83

www.americanradiohistory.comAmericanRadioHistory.Com TIMEX /SINCLAIR PRODUCT DIRECTORY

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www.americanradiohistory.comAmericanRadioHistory.Com . . . CP/M

WW Components, is for the Imsai 8080 I/O Equates and More. In the next permits different physical devices to be computer, and is Version 2.7. section of the listing, headed "I /O Defi- assigned to different logical nition Equates," BIOS tells us some- devices -console (CON:), reader Address Location Arithmetic. All thing about the UART, namely the (RDR:), punch (PUN:), and list (LST:). BIOS listings contain some calculations meaning of each bit when we read the There are also various physical devices at the outset that define and set up the status of an I/O device. Following this like TTY:, CRT:, and LPT:. You can beginning address of BIOS in memory. is a series of equates, which are places change the assignments of physical to Addresses are usually calculated ac- where certain variables and addresses in logical devices by using STAT. When cording to a set of rules laid down by BIOS are given values. The CRT status you do this, STAT changes the Digital Research. They start out by port (CRTST) is at 03H, keyboard data IOBYTE at location 3 in memory. specifying the memory size with which port is at 14H, etc. Notice especially the Now, when BIOS gets a call to the BIOS is working, which is 56K in our printer status (PRTST) and printer data LIST routine, it doesn't know what example in Fig. 18. If your BIOS has (PRT) ports. We'll be using the num- physical device it's intended for until it other statements in it at this point, such bers they're equated to (23H and 22H) checks the IOBYTE. Based on what it as various options that must be set to when we write our printer driver. finds there, it will go to either the driver true or false, ignore them; they won't infor the printer or to some other driver. fluence this discussion. ORG Statement & Jump Table. In the That's why LISTIO and LISTSTIO next section of the listing, "User Cus- (the latter being list status I /O) are a tomized I/O Devices," we finally get to different form of jump table, rather than the ORG statement, which is the begin- driver routines (see "List Out - LST" ning of our program. Usually, this loca- entry under "User Customized I/O De- tion is defined in terms of various other vices" in Fig. 18). locations that are, in turn, defined in This section first calls the DIS- terms of the computer's memory size, PATCH routine, which looks at the among other things. In this case, ORG IOBYTE and determines which of the is at the beginning of BIOS because all four routines to go to for the four possi- disk system drivers are located there, ble physical I/O devices. Because the between D200H and D200H + 0C7OH. line printer is usually assigned to the Our listing is really only a small portion LST: device, DISPATCH determines of BIOS, since it contains no disk this from the IOBYTE and jumps to the information. address in the third DW statement in The magic "N" If we add instructions to BIOS and this routine -LPTOUT (line printer reassemble it to insert our new driver, output). the starting addresses of all drivers fol- In some BIOS versions, the IOBYTE In Fig. 18, we see that MSIZE (corn - lowing the one we changed will be dif- isn't used and this section of code is puter's memory size) is set at 56 (28H). ferent. How will BDOS find them? The omitted. This is true of the BIOS exam- All BIOS.ASM files should have such answer is that it makes use of a clever ple provided in the "CP /M Alteration an equate (EQU). If you want to change programming tool called a "jump Guide" supplied by Digital Research. your BIOS to work with a machine with table." In other versions, it's implemented in a a different memory size, the first thing A jump table is merely a number of different manner. you would do is change this number to a jumps at the beginning of the listing. Refer now to the section of Fig. 18 ti- value that will permit you to take ad- Each jump goes to one of the driver tled "List Character In C," which takes vantage of maximum available memory. routines. Since these jumps are part of us to LPTOUT. We've found the in- The next important number is for the listing we're going to reassemble, structions that tell the UART to accept BIAS. (In other listings, it may have a the values in their address fields will a character and send it on to the printer. different name, such as IOBIAS.) This change when we reassemble the file. So This is the routine we're going to modi- number specifies the distance in memo- BIOS doesn't care about the locations of fy. For a change, it doesn't call another ry between where the CP /M system is the driver routines themselves, only routine. So we've reached the end of the on your system and where it is on a where the jump table is located. The line. Printer status (PRTS) at 23H and CP/M disk as it comes from the factory. jump table is always at the beginning of printer (PRT) at 22H are the "ports" A brand new system is configured for the listing. BIOS calls one of the loca- we're going to access with IN and OUT 20K of memory and then moved up to tions in the jump table, and the jump instructions. the top of memory, where it will reside takes BDOS to the proper driver. IN and OUT Instructions. These are in a particular computer. BIAS is relat- Notice, however, that BDOS assumes the chief means by which the 8080 ed to a certain "magic" number, which the jumps in the table will always be in microprocessor communicates with the we call N. the same order. When it calls on the sec- outside world. IN gets data from a port BIAS is then used to define the start- ond jump in the table, it expects to find and puts it in register A, while OUT ing locations of the major parts of the the jump to LISTIO, not some other sends data from register A to a data CP /M system (CCP, BDOS, and driver. This is why the listing has the port. Of the 256 possible data ports, the BIOS). Location 3400 is the "standard" caution "Do not rearrange jump table" appropriate one is specified by the two - starting point for the bottom of CCP in in it. digit hex number (or label equated to it) a 20K system. CCP is 806H bytes long in the address field. in our listing, since BDOS starts at CCP IOBYTE. Now we can actually start to Data ports and their addresses are not + 806H. CCP and BDOS together are follow a trail through the listing to our the same as memory and its addresses. 1600H bytes long; so in our 56K system, destination. The second jump in the ta- Data ports consist of a separate group of at least, BIOS starts at D200H. ble is to LISTIO, the list device. CP /M registers. Since there are only 256 of

86 Computers & Electronics

www.americanradiohistory.comAmericanRadioHistory.Com them, the ports are addressed by two - of all of the other bits must be zero. ready to accept data for printing. digit numbers. Thus, the 5A in the in- Next, we want to make sure that bits With some printers, you can simply struction "IN 5A" refers to a data port, 7, 2, and 0 are indeed zero. So we XRI wait until they're ready, throw a charac- not to memory address 5A. register A with 85H again. If the result ter at them, wait for ready again, throw The byte read into register A can be is not zero, we go back to check again another character, and repeat until either data, such as an A character with the JNZ instruction. you're done. Such a printer will print (41 H) read from the keyboard, or a Once all bits are properly set in the each character just fine. The printers "status byte" whose purpose is to in- status word, we're ready to receive data. made by Epson are typical examples of form your program about the status of a The data byte has been in register C all such "standard serial" or "teletype - UART or I/O device. The values of a along (your program put it there before like" printers. Other more complex status byte must be known from the op- doing a call to BDOS). So we move it to printers, such as the daisy-wheel mod- erator's manual for the UART or I/O register A and then OUT it to printer els, require one of two advanced proto- device. port 22H. Then we return. col: "xon /xoff' or "etx /ack." The OUT takes an 8 -bit byte from register NEC printer, for example, requires A and puts it into the port specified in I/O Initialization. Usually, the particu- etx /ack, while the Diablo 630 likes the operand field of the instruction. lar UART you're using must be initial- xon /xoff. These protocols are designed This byte can be either data to be trans- ized before it can function properly. to allow a printer to work with more ferred to an output device, such as the Thus, there's a section of code in BIOS than one character at a time. character A to be printed on the CRT that's activated every time you do a XON/XOFF Protocol. You've proba- screen, or a "function byte" that tells warm or cold boot. This routine is bly used xon /xoff without even know- the UART or I/O device what to do. shown in Fig. 18 under the heading ing it. Xon /xoff is the same as the "con - The values to be used in a function byte "Init User I/O IE. Console, Punch and trol -s /control -q" (ctrl -s /ctrl-q) CP/M must be known from the operator's List Dev." uses to freeze and unfreeze the scrolling manual for the UART or I/O device. Different UARTs require different of the display on the CRT screen. In XRI Instruction. This instruction kinds of initialization. You can find out CP/M, ctrl -s freezes the display; strik- performs an exclusive -OR of the one - what yours requires from its spec sheet. ing any key thereafter generates a ctrl -q byte data in the instructions with the In our example, the UART must be told that unfreezes scrolling. Ctrl -s means data in register A. This instruction is "0, 0, 0, 40, AE, 27" before it can do xoff (turn off transmission), while con - useful for testing bit patterns because it anything. Examining the listing, you'll trol-q means xon (turn on immediately tells you if all bits in a cer- note that every time an OUTCRTST is transmission). tain bit configuration are set to 1. Sim- executed, the value in register A is sent A printer uses xon /xoff when it has a ply XRI the bit pattern you want to ex- to the CRT status register (3H). Also, built -in "buffer" that can hold a certain amine with the bit pattern in register A. every time an OUT PRTS is executed, number of characters (1024, for exam- If all the bits you specify are set, but the value is sent to the printer status ple) for printing. The buffer allows the nothing else is, the result will be zero. port (23H). Hence, the sequence of computer to send characters to the For example, if register A contains 07H numbers referred to above is sent to printer at a fairly fast rate and then hold and you XRI it with 85H, you'll have: both the CRT and printer ports of the them while the slower printer mecha- UART. nism prints them out. While the buffer register A 0000 0111 If you're changing from one printer in the printer is emptying, the computer constant 1000 0101 to another, you probably won't have to can be used for more processing, such as result 1000 0010. add anything to this initialization pro- editing a file, during the print operation, cess. But if you add a driver that wasn't without slowing down your text editor. The result is not zero. However, if regis- originally there, you'll have to add code You should notice a delay in processing ter A contains 85H, you'll get: in this section to initialize the new ports only when the printer calls for more in your UART. characters to fill its buffer. register A 1000 0101 This operation is as follows. After constant 1000 0101 Modifying a Printer Driver. To create your printer driver sends each charac- result 0000 0000. a new driver for your BIOS, you must ter, it reads a status word from the first determine the kind of driver pro- printer and looks to see if the printer is Note that the result is now zero. gram to write. You must know what sending back a ctrl -s. If it detects a ctrl - The first thing we do in LPOUT is kind of printer you have and which s, it tells the driver to stop sending be- read the status of the printer port to see communication "protocol" it uses. Pro- cause the buffer is full and to suspend if the printer is ready to receive data. We tocol is another term for procedure. In transmission of characters until the do this with an IN instruction to the this case, it means the procedure by buffer is once again empty. If no ctrl -s is port that holds the printer status (23H), which the printer tells the computer it's sent back, the computer will continue to which returns a byte that looks like that shown in Fig. 19. Now, what we want to see when the DSR SYNDET FE OE PE TxE RxRDY TxRDY printer is ready to receive a character is that DSR, TxE, and TxRDY bits are set. The other bits can be anything at all. We first mask off the other bits with an ANI instruction, using 85H (1000 0101 7 6 5 4 2 0 binary). As a result, only bits 7, 2, and 0 can have a value other than zero; these Fig. 19. The printer port is read to see if it can receive data. bits can either be zero or one. The values

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send characters to the printer until one DSR SYNDET FE OE PE TxE RxRDY TxRDY is detected. Upon detection of a ctrl -s, SIGNAL ....; . the computer goes into a wait loop and ` *' .. ./ waits for a ctrl -q, the signal that buffer o o o o o is empty, to come from the printer. ETX/ACK Protocol. This protocol is B T 7 6 5 4 3 2 o similar to xon /xoff, except that it's im- NUMBER plemented differently. In this case, a Fig. 20. The driver wants to know if it can send a character. block of characters (usually 128) is sent to the printer, followed by an etx character (03H = ctrl -c), which translates to "end of text." After the entire block Testing the Driver. Inserting the new written an appropriate driver routine of of characters has been printed out, the driver into the BIOS and writing it on your own. It may not be perfect, but it's printer sends an ack (06H = ctrl -f), the system tracks of a diskette is some- ready for a preliminary test. Hence, as which means "acknowledged; last what involved. What we need is a way to we describe how to test our routine, you transmission received." test our driver routine without going can follow the same steps with your through this process. Here's how: routine. Writing a Sample Driver. When we 1) We put the driver routine at 100H, First, you must know where to put explored the BIOS listing, we found a just like any other program, using DDT the jmp 100 instruction. This isn't diffi- driver for the simplest kind of and the a command. (It can also be as- cult if you've assembled your existing printer -a teletype-like device with no sembled with ASM.) BIOS into a PRN file. Simply look advanced protocol. We're now going to 2) We put a `jmp 100" instruction at through the listing for the printer driver write a driver for a printer that uses the start of the printer driver routine in routine and make a note of the address xon /xoff. Our example will assume a the BIOS. where it starts (DF35H in our 56K sys- Diablo 630 daisy wheel printer connect- We'll assume at this point that you've tem, as you can see from the last section ed to our CP /M system through a serial board that's running at 1200 baud and uses an Intel 8251 UART.

Look back at the driver in the last sec- LIST CHARACTER I N C tion. When it wants to know if it can send a character, it checks to see if three bits are sent: 7 for data set ready (DSR), , Newxon/xoff printer driver. 2 for transmitter empty (TxE), and 0 for (was just aREl return instruct ¡on.) transmitter ready (TxRDY), as shown LPTOUT: in prts ; input 8251 status in Fig. 20. an i 05h ; AND 8251 for ready to send Using xon /xoff is somewhat more xr i 05h ;exclusive -OR to get zero complicated. We must ask the UART flag two questions. First, js it ready to re- jnz Iptout ; loop unti I UART register is ceive a character from BIOS and, sec- ready ond, does it have a character ready to mov a,c ;get I ist character fromC to give to BIOS. In the first case, we ask A the UART whether bits 0 and 2 are set. out pr t ;output to UART data r egis ter and send In the second case, we want to know in pr ts ;is UART ready with a whether bit 1 (RxRDY) is set. character? With xon /xoff, there are two things ani 02h ;does receiver have a charac- that can occur when a program calls the ter ready? driver to send a character to the printer. xri 02h ;mask

Ìn either case, a character gets sent to rnz ; i f not zero then continue the UART totransmit it to the printer. normally Then, either (1) the UART will not have in pr t ;yes - get the character xoff, in case control will cpi 13h ; i s i t a c t r I- s f r eeze (xo f f) ? sent an which rnz ;no return to the calling program so that it -skip it Ipt1: in pr ts ; i t was a ctrl -s , so now wa i t (2) the can get another character; or for a UART will have sent an xoff, in which ;ctrl -q to return to the call- case the driver won't return an i 02h

ing program but will wait until xon is re- x r i 02h

ceived before it goes on. jnz I pt 1 The listing for the new driver is shown in Fig. 21. We're assuming here in prs character is ready i 11h -q that we don't have to do anything else to cp is itacrtl (xon)? j nz I pt 1 no, so loop untiI it is; i.e. initialize the UART. If we did, we'd let have to add the appropriate instructions pr inter bufferempty to the initialization part of the program. ret finallyactrl -q; return for From the comment given in Fig. 21, you next character shouldn't have any trouble following Fig. 21. Listing for the new driver. operation of the driver.

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www.americanradiohistory.comAmericanRadioHistory.Com . . . CP/M of our BIOS listing given in Fig. 18). system. It may also have part of the location. When it no longer can, that's You can write your driver with a BIOS in it. If the people who configured the top of memory.) word -processing program, assigning the your system didn't put the disk part of In moving this image of CP /M to file the name NEWDRIVE.ASM, as- BIOS in the BIOS.ASM file, they put it high memory, MOVCPM starts off semble it to get a HEX file, and call it in MOVCPM. What MOVCPM may with all 8080 instructions written as if from DDT by the assigned file name. not have in it are the drivers for the oth- they were in a 20K system. It then de- Alternatively, you can type it in directly er I/O peripherals, which are probably termines the difference ( "bias ") be- from DDT using the a command. In ei- in the BIOS.ASM file. MOVCPM may tween a 20K system and the size we ther case ORG it at 100H. have these routines in it, but they may specified, like 56K. Finally, it uses the At this point, your printer shouldn't not work on your equipment or they bit map to change only those bytes that be operating, since you haven't toggled may merely be skeletal drivers that represent addresses in the code (the last it on with a ctrl -p. Use the a command won't work on any system. two bytes of a jmp instruction, for in- to insert a jmp 100 at the start of the When you call MOVCPM, it loads stance). That's it. The resulting new im- driver routine in BIOS. For our particu- three things into memory: MOVCPM age sits in low memory waiting for the lar BIOS, it would be: itself; CCP, BDOS, and maybe part of next thing we want to do with it. Even -adf 35 BIOS in the form of a COM file; and a though the addresses are changed -as if DF35 jmp 100 bit map that tells it which bytes of the the bios were in high memory -it isn't DF38 . COM file must be "relocated" and actually moved there. which don't. Now we save this image, using the Note that you're modifying the very MOVCPM can't put the COM file in SAVE utility. MOVCPM is very helpful BIOS with which you're operating. If high memory, where CP /M normally you do something wrong, the system goes, since the system we're operating with is already there. Remember, you TOP OF can't make major changes to the same MEMORY sections of code that constitute your operating system without getting into ACTIVE" CP /M SYSTEM trouble. So MOVCPM keeps this ver- FBASE of CP in low memory, starting sion /M CBASE SPACE at location 900H, which leaves just AVAILABLE, DEPENDING ON enough room for the program and the SIZE OF SYSTEM bit map below it. This version of CP /M is called the system image, which means 'IMAGE" that the instructions of code look just OF CP/M like the actual operating version of CP /M in high memory but are in the wrong place to actually execute proper- loo ly (see Fig. 22). When you call MOVCPM from .o CP/M, you must specify the memory Fig. 22. The system image of CP/M. Finding a new address. size of your computer, such as 64K, and tell it whether you want the CP /M image to be moved to high memory and ex- may die; so save your files before you get ecute. This is something you almost here because it tells us just what to type: in too deep. never want, since the CP /M image is A > movcpm 56 Now comes the moment of truth. probably incomplete and won't work, CONSTRUCTING 56K CP /M Toggle on the printer with a ctrl -p and resulting in a "crashed" system if you vers 2.2 READY FOR "SYSGEN" OR RETURN a few times. The printer attempt to execute it. If you don't want hit "SAVE 45 CPM56.COM" should respond. Now type something this to happen, you can type an asterisk A> and hit return. Whatever you type after the size: "A > movcpm 56 *" in should be printed out, including the re- which the "56" means that you want to At the A > prompt, we type "save 45 turn. If something other than what you generate a 56K CP /M system and the cpm56.com ". The image is 45 256 -byte typed or nothing at all is printed, either " *" specifies that the image is to remain "pages" long, and MOVCPM suggests your driver is defective or your jmp 100 in low memory, where it's not to be relo- that we call the file "CPM56.COM ". is in the wrong place. cated or executed. You can also use an asterisk in the Urge to Merge. Once we have the Installing the New Driver. Once memory field if you want to simply use CPM56.COM file of the CP/M image you've gotten your driver to work in this all available memory: "A > movcpm safely stored on disk, we merge the nonstandard location, it's time to install *" (takes 64K in a 64K system, 48K in a BIOS.ASM file, which we've modified it in your CP/M system. However, be- 48K system, etc.). In our particular by putting our new driver into it, into fore you can complete this process, you case, we can't do this because the upper CPM56.COM. To do this, we use a spe- must learn about the MOVCPM and 8K in our computer, although present, cial technique in DDT and the magic SYSGEN utilities in CP /M and that is used for special video drivers. (The number, N. Then we take the resulting magic number N. routine determines how much memory complete image and write it onto the MOVCPM. This amazing program the computer has by testing higher and system tracks of a formatted, blank actually contains CCP and BDOS, higher addresses to see if it can put disk, using SYSGEN. We'll call this file which is most of the CP /M operating something into and read it out of each "CPM56n.COM," where n is "new."

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The Magic Number N. N is simply the page boundary, we figure it's probably address of the file. Thus, if we have a difference between where MOVCPM at BCOOH. HEX file ORGed at, say, D200 and we puts the CP /M image and where CP/M Another way to find CBASE is to ex- want to load it into memory somewhere actually goes in high memory, as shown amine the BIOS.PRN (not ASM) list- else -say, at 1F80 -we simply find the in Fig. 23. Notice here how the CP /M ing. CBASE and several other fascinat- difference between these two numbers image placed in low memory by ing addresses are often part of the and type it into DDT following the r MOVCPM is related to the CP /M im- address location arithmetic in the begin- (read) command. As you can see, this is age that will be placed on the system ning of the file. Checking this file, we the same old magic number, 4D80. For tracks of the new disk. This new image find that BCOOH is, in fact, the start of example, if we want to load with bias a will occupy exactly the same addresses CCP. HEX file called NEWBIOS.HEX that as the CP /M currently running in high DDT has a handy function that per- is ORGed at D200, we'd do the memory, except for the changes made to forms arithmetic on hexidecimal num- following: BIOS by the new driver. bers. While in DDT, you can use this -inewbios.hex CCP is located at 980H in the system function by typing "hx,y" after the - -r4d80 image but will be at BCOOH in our 56K prompt, where x and y are four -digit hex and the file will be placed in memory at system when actually installed and run- numbers. For any two hex numbers, location 1F80. ning; BDOS is located at 1186H in the DDT will print out the sum (x + y) and image but will be at C406 when running, difference (x - y). In this case, we want Inserting the New Driver. At this etc. You can see that all these pairs of to know the difference between, say, point, you should have a working driver numbers are related by the same con- 980H and BCOOH. It would also be nice routine that you're ready to insert into stant, which can be found by subtract- if we obtained a negative number so we your CP /M operating system. The first ing any two of them. could later simply add it to other num- thing you want to do is create a new ver- bers to perform the conversions. sion of the BIOS.ASM file, one that in- Finding Addresses. To find the magic If you type "h980,bc00" after the corporates the new driver. (Remember number N, we must know at least one DDT prompt, DDT would respond that this file might have a different pair of addresses-one in the with "C580,4D80 ". It's the latter differ- name, depending on your system, such MOVCPM image in low memory, the ence number, 4D80, we want, which is as BIOS.ASM, GBBIOS.ASM, etc.) other in running CP/M in high memo- our so- called "magic" number. We Start by making a copy of the old ry. A good one to work with is CBASE, must know this number for two reasons. BIOS.ASM file and call it newbios.asm which is the bottom of CCP. The first First, we want to be able to look at cer- by typing "pip newbios.asm= half of this is easy because in the system tain sections of code in the MOVCPM biosio.asm" after the A> prompt. image, CCP is always at 980H, no mat- image in low memory and know what Bring NEWBIOS.ASM into your word - ter what size system you have. CBASE we're looking at. We know where things processing or text -editing program. De- for high memory isn't quite so easy to are in BIOS in high memory, from lete the program lines for the existing find. However, if you examine locations BIOS.ASM, and we must be able to driver. Then either type in the assembly 6H and 7H in memory while CP /M (not translate this into equivalent locations code for the new driver or, if your DDT) is running, you'll find an address in low memory. The magic number does word processor will permit it, copy that's close to the start of BDOS. CCP is this, as we shall see. the file containing the new driver usually about 800H bytes long; so if you The second reason we must know this directly into the correct location in subtract 800H from this address, you number is that we're going to use NEWBIOS.ASM. Also, if you have to obtain CBASE, in our case, C406 - 800 DDT's ability to load a HEX file with a add anything to the initialization part of = BC06. Knowing that CCP starts on a "bias" (offset) instead of at the ORG BIOS, to get the UART off on the right foot, now is the time to do it. Reassemble the new BIOS by typing "asm newbios" after the A > prompt. DFFF You now have NEWBIOS.HEX and NEWBIOS.PRN files. You can now use D200 MOVCPM to create the CP /M image, FBASE C406 as described above. If you already have CBASE BC00 the system image (CPM56.COM or whatever) stored as a file, you can skip UNUSED BB80 this step. IMAGE 2D7F WRITTEN You're now going to use DDT to do TO IF80 SYSTEM the actual merging of the new driver TRACKS into the system. Load the system image 1186 as you call DDT by typing "ddt 980 cpm56.com" after prompt. ALL THESE PAIRS the A> 900 OF NUMBERS ARE (Don't forget that the number after cpm RELATED BY THE SAME CONSTANT in the file name will be different for different -size memory systems.) To make 100 certain that everything is where you Fig. o 23. The magic number N is the think it is, use DDT to explore this im- IMAGE difference between where MOVCPM age by looking at the beginning of CCP, IN puts the CP /M image and where MEMORY as shown in Fig. 24. It should be the CP /M actually goes. same as the running CCP in high memory. You can check this out by typing

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new system; so we type a "dbc00" after the DDT prompt; it -g0 generate our after the A> should be as in Fig. 25. Note that the ad- A> save 45 cpm56n.com "sysgen cpm56n.com" the n). SYSGEN dress column, should now read "BCOO, The 45 is the same number of 256 -byte prompt (don't forget in Fig. 26. Note that BC10, BC20, etc." instead of the low - pages that MOVCPM told you to save; will reply as shown the destina- memory addresses. this number will remain the same unless you must type a b to specify RETURN once the desti- Using the d command lets us see that tion drive and a B:. SYSGEN will write the sign -on message is really there. nation disk is on system Check the beginning of BIOS to see if the new version of the operating tracks of the new disk. this is where the jump table is: onto the system You're done! You now have a new system -11f80 custom -configured operating 1F60 JMP D3D3 that you've made yourself. Test it using 1F83 JMP D334 DIR, and use TYPE to see if it will real- 1F86 JMP DE79 ly print out when you toggle your print- 1F89 JMP DE7C er with a ctrl -p. If you're testing an (etc.). xon /xoff or etx /ack printer, you'll have characters at one time to A look at the running BIOS in high to send enough memory should be the same, again with fill up the print buffer. exception of the addresses. Now find the Summary. Once older driver routine, if there was one, in Driver Installation familiar with this in- the system image and in the running you become very this is what you'll be BIOS. They may not be the same. stallation process, typing on- screen. (We're assuming you at all with Merge In New BIOS File. We're now aren't going to check memory memory size and the going to use DDT to merge the DDT.) Of course, file into the CP /M number of pages to SAVE will depend NEWBIOS.HEX XON /XOFF protocol. image in low memory. This is where we on your specific system. number N. Although A> pip newbios.asm = biosio.asm use offset to NEWBIOS.HEX is ORGed in high You add your driver a word proces- memory (at DE70 in our case), we want your modification has expanded BIOS NEWBIOS.ASM with store the revision as to lay it down on top of the BIOS part of past a page boundary. The n simply sor and then the system image in low memory (at means "new." NEWBIOS.ASM: 2BFO in our system). We're now ready to create a new sys- A> asm newbios Type "inewbios.hex" after the DDT tem disk. Start by placing in drive B a prompt to put the file name in FCB. formatted disk. SYSGEN is often used A > movcpm 56 Then type "r4d80" to read in the file to simply copy the current CP /M sys- A> save 45 cpm56.com with an offset of 4d80. Now look at the tem from the system tracks of the work- needed ev- image with the / command to ascertain ing disk to those of a formatted disk. In These last two steps won't be that the new driver is where you want it that case, no file name is specified when ery time. ddt cpm56.com to be. If it is, you're ready to save the im- SYSGEN is called. However, we want A> onto the disk: to use the CPM56n.COM file when we age as a file back -inewbios.hex -r4d80 -go

-d980 A > save 45 cpm56n.com 0980 C3 5C BF C3 58 BF 7F 00 20 20 20 20 20 20 20 20 .\ .. X ... 0990 20 20 20 20 20 20 20 20 43 4F 50 59 52 49 47 48 COPYRIGH A > sysgen. 09A0 54 20 28 43 29 20 31 39 37 39 2C 20 44 49 47 49 T (C) 1979, DIGI (etc.) That's all there is to it. By going Fig. 24. The image at the beginning of CCP. through this procedure a few times, you'll be gaining valuable understanding of the BIOS in general and experi- -dbc00 ence in manipulating it according to .. BC00 C3 5C BF C3 58 BF 7F 00 20 20 20 20 20 20 20 20 . \ X... specific needs. BC10 20 20 20 20 20 20 20 20 43 4F 50 59 52 49 47 48 COPYRIGH 37 39 2C 20 44 49 47 49 T (C) 1979, DIGI BC20 54 20 28 43 29 20 31 39 Comes the End. This concludes our (etc.) series, which was excerpted and con- The Fig. 25. The running CCP in high memory. densed from the forthcoming book Soul Of CP /M. We've covered here only highlights of portions of what the book SYSGEN VER 2 . 0 hope you've (OR RETURN TO REBOOT) b covers in greater detail. We DEST I NATION DRIVE NAME enjoyed your journey through the fasci- , RETURNRETuRN DEST I NAT ION ON B THEN TYPE FUNCTION COMPLETE nating realm of CP/M and have added TO REBOOT) RETURN knowledge of this I RETURN to your DEST I NATION DR VE NAME (OR considerably system for Fig. 26. SYSGEN replies to the prompt for the new file. powerful popular operating small computers.

Computers & Electronics 92

www.americanradiohistory.comAmericanRadioHistory.Com 2e44.41,41, 16-BIT MICROCOMPUTER TECHNOLOGY Part 6: How to Use Machine Language Programming By George Meyerle

PREVIOUS articles in this series should and we will gain some practice using it However, the flashing LED approach have convinced you that, before you can with the monitor program resident in was hard to use and scared away many understand, repair, or design micro- the IBM -compatible, 16 -bit Explorer casual observers. On the other hand, computers that use the latest generation 88 /PC microcomputer. ROM -based monitors, including that of hardware, you must have had at least Quickly reviewing the design of the used in the Explorer 88, are easy to use an introduction to machine /assembly Explorer 88, recall that it can be set up and understand; and, with a litle prac- language programming. By using ma- to operate in 3 different modes. The tice, you should be able to write short chine language subroutines in conjunc- first, and least expensive mode ($400), programs in 16 -bit 8088 machine lan- tion with BASIC or other high -level allows accessing the monitor program guage. Since it is not practical to write languages, it is possible to increase exe- using a standard terminal connected to long programs or subroutines without cution speed and, in some cases, allow the RS232 port. The second choice the help of an assembler, once the basics operations that are not possible using (about $600 more) is to add an IBM - are learned, it is suggested that you in- the high -level interpreter alone. This compatible keyboard, color board, and vest in one of the many available assem- month we will discuss how to learn ma- either a color or black /white monitor. bler programs. chine- language programming painlessly This gets you that much closer to being truly IBM -compatible. The next step in- Monitor Overview. All 8088 micro- volves the addition of a floppy -disk card processors auto -boot on power -up or re- TABLE VI -I /O PARAMETER and up to four floppy drives. At this set to location FFFFOH. This location, SETTINGS point, you can run IBM -PC DOS or any in the Explorer monitor, contains a of the many IBM -compatible disk oper- jump to location FE000H which is the ating systems, including Digital Re- beginning address of the upper -most 8K Baud rate S1 -3 S1 -2 S1 -1 search CP /M -86, all of which include of ROM and of the monitor program 110 On On On fine monitor or debugging programs. 150 On On Off The following applies to any configura- 300 On Off On tion selected. 600 On Off Off TABLE VII- MEMORY MAP 1200 Off On On 2400 Off On Off Monitor Programs. In its simplest 00000-OFFFF RAM FE000-FFFFF 4800 Off Off On form, a monitor program is a collection ROM 9600 Off Off Off of routines that allow programs to be 00000-00003 Divide -by -zero interrupt generated, tested, modified, and saved 00004-00007 Single -step interrup 00010-00013 Overflow Parity disabled: S1 -4 on for interrupt future use. The original microcom- 0000C-0000F Parity enabled: S1 -4 off Monitor -trap puter monitors consisted of a front pan- 00010-0002F Parity odd: S1 -5 on System el array of switches and LEDs that al- 00030-00033 Parity even: S1 -5 off UART interrupt lowed access to the CPU and memory. 00034-OFEFF System

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terns and then checking the results by reading the registers. If all tests are passed, the count register is set for a 64K system and channel 0 is enabled so EXPLORER HR MONITOR that the RAM refresh process can

MON TOR begin. COMMAND ENTRY POINT The program then sets up the inter-

SYSTEM TEST rupt controller mode registers and AND 5: Tl ALII ATION masks off all interrupts. This is followed by the initialization of the 8255 system and timer control ports. The monitor then sets up the data and stack segment HALT R registers and the stack pointer. It also clears the console input and output buffers. The 8250 UART is then initialized. This process involves reading the switch # 1 at port B of the 8255. These OR PROM CHECK -SUM switch settings determine the baud rate TEST (Table VI) to MEMORY and parity selections L SFL AY /MODIFY which the UART will be initialized. The monitor also downloads the interrupt jump vectors to the lowest locations in TIMER TEST INITIALIZE FOR RAM as shown in the memory map in DMA REFRESH Table VII. Note that the top 256 bytes in the first 64K bank are reserved for the stack and other monitor operations. After testing the hardware and set- TEST AND INITIAL. IZ) ting the UART, the monitor idles at the DMA CONTROLLE!- GO TO START MODE awaiting entries REFRESH Command Entry Point from the keyboard. The program is set up so that it will only accept valid commands. All invalid entries will result in

SET UP the display of "? ?" and the abortion of INTERRUPT CONTROLLER the process attempted. Valid commands are: D Display memory contents

TEST R Register display/modifica- AND T UP H255 SYSTEM HORT tion (READ TOTEM TWIT HES) B Block move of memory M Memory modification/ display I Input one byte from an I/O SET UP TIMER ONTROL device PORT AN INITIALIZE TIMER ZERO O Output one byte to an I/O device CO Cassette output from memory to cassette TEST Cassette input from cassette to AND INITIAL IZI CI DART HARDWARE memory COMPLETE T Trace instructions HARDWARE TEST TR Trace instructions with register report G Go run from memory with op- Fig. 18. Flowchart of the monitor program. tional breakpoint GR Go run from memory with optional breakpoint and register whose flowchart is shown in Fig.18. test. This adds the contents of all 8K of report Note in this flowchart that, before the ROM and compares the results with the HT Hardware tests of ROM, program is ready to accept commands correct answer. RAM, cassette, interrupt con- from the keyboard, a preliminary hard- The next component tested is channel troller, timer, DMA control- ware check is made. If any hardware 1 of the timer. If the timer test is OK, ler and UART. test fails, the CPU is automatically halt- channel 1 is programmed to provide the ed. The program begins by checking the refresh clock signal to the DMA con- In future issues, we will show how to CPU. All registers, including the flags, troller. Next the DMA controller is use the ROM -based monitor in practi- are tested. If they are OK, the program tested. The count and command regis- cal programming. continues with a PROM check-sum ters are tested by writing various pat- (To be continued)

94 Computers & Electronics

www.americanradiohistory.comAmericanRadioHistory.Com TELETEXT EXPERIMENTS BY NETWORK Computers may cover the world on this latest communication network, now being tested in the U.S. By Leslie Solomon

WHILE we computer types have been ping of the next field's video ted by these networks, you will see some busy designing new computers and information. full lines of very busy signals. An exam- putting new software together, others Until recently, the vertical interval ple of each is shown in the accompany- have also been very busy (and very qui- contained engineering test signals such ing photos. The Teletext signals occupy et) doing something that might affect as multiburst, color bar test, a compos- the four horizontal line intervals leading the future of computing as we know it. ite test signal, VIR (for auto color setup to the conventional test signals. (If A couple of times during the past few ting), and various forms of digital test you are looking at the interval on a TV years, I have written about signal activi- signals used by the networks -nothing receiver, the Teletext signals are those ty during the vertical interval of the very exciting except for those people in- "grassy" lines slightly above the top of NTSC TV signal. To see this interval terested in such doings. the picture.) These signals are not to be and the activity, all one has to do is ad- Most of us have heard of "Teletext," confused with the closed captioning just the vertical speed of any TV receiv- and usually associated it with happen- currently used by ABC and PBS as an er until the wide, dark horizontal bar ings in European TV -the BBC has aid to the deaf. appears in the display area. This dark been using it for years, and the French According to the North American bar is the vertical interval and it occu- have been involved with their Antiope Broadcast Teletext Specification, this pies some 20 horizontal lines. If you approach. Some might have even been activity may be extended to encompass look at the lines immediately above the aware that there is some Teletext activi- lines 10 through 14, and may even reach picture, you will see several strange - ty next door in Canada, and that Japa- the full field. Hardware people should looking sets of dots and bars, some in nese stations were testing a form of this keep in mind that this data is being color and some appearing to be in mo- new digital signal. transmitted through a 4 -MHz channel tion. If you have a good scope and ac- Now, Teletext is here in the USA, and (begins to look like a disk to you ?). cess to the receiver video signal, you can being tested by NBC and CBS. If you What is being transmitted? At the take an even closer look at the interval take a look at lines 15 through 18 of the present, only test data. But even this can between the vertical sync and the begin- current vertical interval being transmit- consist of a very large number of pages, selectable via a hand control attached to the TV decoder. The user can page through the system in the same way as paging through the menus on The Source, Compuserve, or any other data base, and thus pick and choose his /her subjects. Unlike the data base, the received data can be in color, and even reasonably high -resolution color graphics can be displayed (using the color -TV receiver as the monitor). And there is almost no end to the number of pages that can be sent. Page updating can occur in real time as fast as someone can type. It is not beyond the range of probabil- ity that a computer can be used to download data from this TV source, with all types of software being made available. Furthermore, with a telephone attachment, interacting (or even data storage) can be attained. One other thought: now that we have battery- powered TV receivers, battery -powered computers, and direct satellite -to -home TV in the offing, we are in a position to have worldwide software distribution. Computers will really cover the world in the very near future, even if you are in a canoe paddling up the Amazon. Top and center are Teletext signals on NBC and CBS respectively. At bottom are We shall have to keep an eye on fur- closed- caption signals on PBS. ther Teletext operations.

August 1983 95

www.americanradiohistory.comAmericanRadioHistory.Com THE ELECTRONICS SCIENTIST

Considering the peripherals already The market for non -watch liquid -crys- available for existing personal comput- tal displays, for example, more than ers, one can envision a new family of doubled between 1980 and 1982. highly sophisticated peripherals for the Among the first commercial "high - new generation of portable computers resolution" liquid- crystal displays was represented by machines like the Model the 16 by 16 element unit used in Mil- 100. ton- Bradley's "Blockbuster" handheld For example, consider the Model 85 game. I was so impressed when this toy aScope" module that transforms the was introduced several years ago that I Apple II into a powerful, programma- immediately bought one for my son. To- ble dual -trace oscilloscope with memo- day, of course, the resolution of the ry capability and a 50 -MHz bandwidth. "Blockbuster" screen is downright This computer accessory, which is primitive when compared to the 220 by made by Northwest Instrument Sys- 240 display elements (pixels) of Toshi- tems, Inc. (PO Box 1309, Beaverton, ba's handheld television receiver. This Flat -Panel Displays OR 97075), and others like it have receiver's two -inch screen is made by greatly expanded the potential role of applying a thin film of nematic liquid A Tunable 60 -Hz personal computers and, at the same crystal to a 51.4 by 41.4 -mm silicon chip Hum Filter time, alarmed makers of conventional containing an array of 220 by 240 test equipment. And if the conventional PMOS switching transistors. By Forrest M. Mims, Ill test equipment companies are worried A single pixel consists of a PMOS now, just wait until instrumentation transistor and a capacitor. When the Flat -Panel Displays peripherals become available for the gate of the transistor is strobed by the portables (rest assured they will). video scan signal, the capacitor is Will Revolutionize Hopefully by now you can under- charged to the appropriate video signal Information Processing ' stand my enthusiasm for the new flat - level. The capacitor holds its charge un- panel display technology. But you'll til refreshed by the next strobe signal. have to actually see and use a product Toshiba's researchers found that the the picture MORE and more new products are ex- with a large- capacity flat -panel display electrodes that interconnect ploiting the rapidly advancing state of to fully appreciate the convenience and element transistors must be highly re- mirror. Oth- liquid -crystal and other flat -screen dis- portability it offers. You'll probably flective and as smooth as a light play technologies. These products will have that opportunity soon, considering erwise, undesirable scattering of reduce revolutionize the way many of us pro- the rate at which new products are being within the display would greatly They eventually cess information both at home and at announced. Meanwhile, let's examine its apparent contrast. elec- work. some of the technical aspects of flat - selected platinum for the reflective and is They will, for instance, make "per- panel displays. trode since it appears very white sonal" computers truly personal. After therefore well suited for a black and all, have you actually considered as Liquid -Crystal Displays. Thus far liq- white television display. diagram "personal" a computer system that fills uid crystals are dominating the com- Figure 2 is a simplified block Note the pres- a tabletop with its television monitor, mercial flat -panel display market. A few of Toshiba's display chip. keyboard, disk drives, and other para- years ago makers of the comparatively ence of two gate bus drivers (to address ends phernalia, all connected by a bird's nest simple liquid -crystal readouts used in the rows) and connections to both of cables and wires? digital watches took a beating due to se- of the drain buses (to address the col- Portable computers with all the fea- vere competition. Many companies ei- umns). This redundancy is part of a tures of today's desktop units will be ther abandoned or were 'forced out of clever design ploy to salvage chips that made possible in part by large- capacity the liquid -crystal readout business. may have defective bus driver elements liquid -crystal and other flat -panel dis- The market for high -resolution, flat - or bus lines. Such built -in redundancy plays. Applications for these portables panel, liquid -crystal displays, however, has become a standard design technique circuits will go beyond the standard word -pro- was unaffected by this development. for very large scale integrated cessing, spreadsheet, and communications packages. For example, a portable computer with a flat -panel display Fig. 1. Radio Shack's Model 100 has an LCD with 15,360 pixels. could be used as an oscilloscope. The display on the new Radio Shack Model 100, for example, has 64 by 240 1). or 15,360 elements or pixels (Fig. f'ASI<, TELCQM This is more than adequate for a low - SCHEDL.DO NOTE.D-O resolution solid -state oscilloscope. In- deed, many of you may recall the series '4874 of "Experimenter's Corner" columns several years ago in this magazine in which I described various kinds of do -it- yourself flat -screen LED oscilloscopes. The maximum resolution of those simple scopes was only 10 by 16 elements.

www.americanradiohistory.comAmericanRadioHistory.Com (VLSI), especially memory chips. tice, so only six of the bonding pads are vision receivers, a third major market Figure 3 is a cross section of the edge required! for flat -panel liquid -crystal displays is of the Toshiba display. The silicon chip, Toshiba's display is typical of what compact oscilloscopes. The pioneer in which is very thin and fragile, is mount- can now be done with high- resolution this field is England's Royal Signals and ed on a very flat and sturdy glass sub- liquid -crystal flat -panel displays. Its Radar Research Establishment. Dis- strate. A 10- micron layer of mixed ne- display achieves a contrast ratio of 20:1 play technology developed there has matic liquid crystals is applied to the and has a response of only 30 ms. While been used by Scopex, Ltd. to produce chip. The assembly is topped by a pro- I've not been able to determine the pow- the Voyager flat -screen scope. tective window that includes a transpar- er consumption of the display alone, the The Voyager has a screen resolution ent conductive film on its inner surface. complete miniature television receiver of 128 by 256 elements for a total of This provides the display's counter in which it is used consumes only 1.3 W. 32,768 pixels. Easily viewed in bright electrode. This is certainly higher than a portable sunlight, an advantage shared by most Since the chip includes its own gate radio of similar size, but it is less than liquid -crystal displays, the Voyager has bus drivers, actually multiplexers, only the 1.8 W consumed by Sony's minia- a frequency response of 150 kHz and twelve bonding pads are necessary to ture television, which uses a flat cath- weighs 2.5 kilograms. It operates for up access all 220 gate buses. Only one of ode -ray tube. to 12 hours from self-contained re- the two gate bus drivers is used in prac- After miniature computers and tele- chargeable batteries.

PICTURE ELEMENT DI D2 D240 SWITCH TRANSISTOR VD02 VDD2 DISPLAY V002/GNO ELECTRODE VD02/GNO

I V DO I / GND VDD / GND GND GND CPH TSTORAGE CPH CAPACITOR STH STH DRAIN BUS

GATE BUS ,

02 D240

Fig. 2 (above). Toshiba's liquid crystal display. +V HORIZONTAL Fig. 3 (below). Cross section of Toshiba's LCD. VERTICAL DEFLECTION DEFLECTION PLATES PLATES Fig. 4 (right). Construction of Sinclair flat CRT.

OBSERVER ELECTRON BEAM FRESNEL LENS COLLIMATOR GLASS ELECTRON GUN WINDOW ELECTRIC CONDUCTIVE HOSPH0R +V FIELD FILM SCREEN SPACER LIQUID CRYSTAL I -I ELECTRODE PLATINUM SILICON ELECTRODE SUBSTRATE -V TRANSPARENT TIN OXIDE FRESNEL LENS GLASS ELECTRODE SUBSTRATE

August1983 97

www.americanradiohistory.comAmericanRadioHistory.Com ...ELECTRONICS SCIENTIST

At $6000 the Voyager is not intended tube is virtually identical to that of the siderable work has been expended on for the general market. Instead, it's tar- Sinclair tube. The only significant dif- light- emitting diode arrays, they require geted for use in explosive atmospheres ference between them is their physical much more operating current than most and for applications requiring the ulti- appearance. The Sinclair tube is shaped other displays. More promising are elec- mate in portability. Considering the like a flat rectangle. The electron gun of troluminescent and cathodolumines- rapid advances in flat -panel display the Sony tube is enclosed in a neck -like cent devices. We will probably hear technology, I'm sure it's only a matter extension projecting from one side of more of this in the future. of time before compact battery -powered the square display portion of the tube. scopes with liquid -crystal displays be- Figure 5 illustrates the physical differ- Comparing Flat -Panel Displays. come available for a few hundred ence between the two tubes. Each of the various flat -panel technol- dollars. Figure 6 shows a demonstration ver- ogies has relative advantages and disad- sion of still another kind of flat -panel vantages. Liquid -crystal panels use very Other Flat -Panel Displays. Consider- display, a plasma dot -matrix readout little power and are ideal for battery - able work has been undertaken over the panel made by Sigmatron Nova (1901 powered equipment. Furthermore, they years to develop various kinds of flat - Oak Terrace Lane, Thousand Oaks, CA are easily viewed in direct sunlight, panel displays. Most effort has centered 91320). The Sigmatron displays are something that surely cannot be said of around the ubiquitous cathode -ray tube available with from 1.3 to 150 cm' of ac- some light -emitting displays. (CRT). Among the first firms to devel- tive display area. At least two versions On the other hand, liquid- crystal dis- op a viable flat -panel CRT for miniature are now in production. Model TE 1 X 32 plays are relatively fragile and tempera- equipment is England's Sinclair Re- is a 32 by 32 array having 1024 pixels, ture sensitive. And they can sometimes search (Fig. 4). and Model TE 1 X 56 is a 56 by 56 array be tricky to view. For example, the dis- In a conventional CRT, electrons are having 3156 pixels. Both arrays have an play of the Model 100 can be difficult to propelled at right angles toward a phos- active display area of 2.6 by 2.6 cm. view when observed at some angles. phor- coated screen. In Sinclair's tube, These demonstration plasma panels When the external lighting is just right the electron gun is located to one side of are installed in an enclosure complete for the operator, others wishing to read the phosphor screen. The electron beam with 12 -V rechargeable batteries, ana- the display may have to stand behind is propelled across the surface of the log and digital input ports, and the operator. screen and then bent toward the screen microprocessor routines derived from Light -emitting diode displays have by an electrostatic field. The screen is an 8K EPROM and a 4K RAM. Dem- the potential of being much more rug- viewed through a window coated with a onstration routines include alphanu- ged and having much longer operating transparent film of tin oxide which meric characters, graphics, scrolling, lifetimes than other kinds of displays. serves as one of the focusing electrodes. and a real -time oscilloscope. These are But they are expensive to make and they According to Sinclair, since the ob- just some of the possibilities. use considerable current so their popu- server views the phosphor screen from Because of the nature of their written larity depends on these factors. the side struck by the electron beam, the language, Japanese companies have al- Like liquid -crystal displays, plasma screen appears twice as bright as the ways been highly motivated to design and cathodoluminescent displays are screen of a conventional CRT having very high -resoluion flat -panel displays. made largely from glass and are there- the same beam energy. One of their latest entries in plasma dis- fore fragile. Worse, these displays re- Though Sinclair Research announced play technology is a Sony panel with quire considerably higher operating in 1981 that it was entering a four -year 512 by 1024 addressable dots for a total voltages than those using liquid crystals program aimed at putting its miniature of 524,288 pixels! This remarkable dis- or light- emitting diodes. This greatly in- flat -screen CRT into volume produc- play has a resolution of 127 lines per creases the difficulty of designing suit- tion, Japan's Sony Corporation was the inch. It easily displays complex Chinese able drive circuitry. Electroluminescent first company to introduce a miniature and Japanese characters and provides displays are sturdier than those that re- television receiver using a remarkably excellent graphics capabilities. quire glass packaging, but they, too, re- similar flat -screen CRT. Other flat -panel display technologies quire relatively high drive voltages. The operating principle of the Sony are also being developed. Although con- (Continued on page 100.)

Fig. 6. Sigmatron Nova hi -res plasma display demonstrator. PHOSPHOR SCREEN

SINCLAIR SONY

GLASS ENVELOPE

Fig. 5. Comparison of Sinclair and Sony miniature, fla CRTs.

www.americanradiohistory.comAmericanRadioHistory.Com Did you ever and how they work...the difference be- Drojects. And, there wonder how an Elec- tween Beta and VHS formats...optical Are complete glossaries of tronic circuit works? How a com- versus capacitance electronic disc sudi) and cpmputer technical terms! puter computes? What to look for when videodiscs...home satellite televi- Lsvitatior. to Electronics. It contains buying audio, video, communications sion...how a television set creates its everything you need to know to get or computer equipment? image ...component television ...pro- started in the exciting world of elec- You'll find the answers to these ques- jection tv... how stereo tv will revolu- tronics anc computers. Order your tions -and practically every other basic tionize the field. copy today! personal electronics question -in the HOBBY COMMUNICATIONS 1983 Invitation to Electronics! GEAR. Invitation to Electronics is the com- The two basic elements of any plete guide to home electronics prod- commu- ONLY $3.95! ucts from the Editors of nications system...the superhet re- Computers and ceiver...why Electronics magazine (formerly Popu- you need an antenna lar Electronics). With photographs, ...shortwave receivers...DXing (pick- drawings and detailed ing up broadcasts from around the articles, it ex- world)...public plains the inner workings of: safety scanners...CB ...marine and ham radio. PERSONAL COMPUTERS. PLUS: You'll learn all about electronic What.a computer is and how it works... circuitry...components and how to the truth about computer intelligence... identify them...integrated circuits and memory ...peripherals ...software ...disk "microchips"...how to solder and de- drives.. . printers... modems...languages solder...how to build projects...sample ...pocket computers... features of the newest models of microcomputers. AUDIO EQUIPMENT. INVITATION TO ELECTRONICS How should systems get the music to CN 1914 Morristown, NJ 07960 your ears ...amplifiers ... preamps .. . Please send me INVITATION TO ELECTRONICS. I enclose $4.95 ($3.95* plus ... turntables ...receivers...tuners...cassette $1.00 postage and handling). $6.00 outside U.S.A. decks ...speaker systems ...headphones ...signal processors...car Mr. /Mrs. /Ms stereos...the (please print full name) new compact optical discs... microcas- Address Apt sette...how to choose audio components. City State lip *Residents of CA, CO, CT, DC, FL, IL, MA, MI, MO. NJ, NY State and VT add applicable VIDEO EQUIPMENT. sales tax. Videocassette recorders and videodiscs

www.americanradiohistory.comAmericanRadioHistory.Com ...ELECTRONICS SCIENTIST

An Easily Adjusted Switched -Capacitor +5V 60 -Hz Hum Filter SIGNAL R3 10K IN RI In the "Project of the Month," in Sep- I0K 4 tember 1982, I described two active 1/2 notch filters designed to block 60 -Hz R2 NOTCH 10K MF-l0 hum. Both these filters used a single op- OUTPUT erational amplifier and six or seven out- board resistors and capacitors. 4- 5V Newly developed switched- capacitor filters such as National Semiconduc- tor's MF -10 can provide improved 60- Hz hum rejection. A basic 60 -Hz notch R4 = R5 100K 500K filter requires only three external resis- CI tors and no capacitors. A 300- or 600 - *-5V BYPASS TO GND .01 »F Hz clock signal is required, however, so WITH 5)c= I/6 4049 there are no component savings over TIE UNUSED OUTPUTS OF 4049 GAIN =R2 /RI conventional op -amp 60 -Hz notch TO +5V OR GND 0 =R3 /R2 filters. Fig. 7. Switched capacitor 60 -Hz hum filter. Though they are more expensive than conventional op-amp active filters, the center frequency (fo), gain, and Q of a +10 switched -capacitor notch filter are all o easily adjusted. This means virtually m any degree of 60 -Hz rejection can he Z -10 o

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www.americanradiohistory.comAmericanRadioHistory.Com PREVENT HI -TECH ENGLISH HEADACHES BROADCASTS Our Isolators eliminate Audible in equipment interaction, clean up interference, No. AMERICA curb damaging power line spikes and (Continued from last month) lightning bursts. By Glenn Hauser IS0-1 Isolator TIME' TIME 3 isolated sockets; quality spike CSI il Tr GMT SIAT ION QUAL2 FREQUENCIES, kHz3 suppression; basic protection. $76.95 7:00 p.m. 4:00 a.m. 0000-0900 UN Radio 6055 (when in session) 7:05-8:55 p.m. 0005-0155 Spanish Foreign R. 11880, 9630 ISO-3 Super -Isolator 7:30-8:00 p.m. 0030-0100 R. Prague 6055 7:30-8:00 p.m. (+) 0030-0100 R. Budapest 17710, 15220, 11910, 9835, 9585, 3 dual isolated sockets; suppressor, 6025 (Wed. & Sat.) 7:30-8:00 p.m. 0030 -0100 La Cruz del Sur, Bolivia 4875 (Mon. only) commercial protection 115.95 7:30-8:15 p.m. 0030-0115 BRT Belgium 11625, 9880 7:30-8:30 p.m. 0030-0130 HCJB, Ecuador 15175 ISO-17 Magnum Isolator 7:30-9:00 p.m. 0030-0200 R. Mexico 17765, 15430, 11770, 9705, 5985 (Sat.) 4 quad isolated sockets; suppressor; 7:30-9:30 p.m. 0030 -0230 SLBC, Sn Lanka 15425 7:30-9:30 p.m. 0030 -0230 BBC 15260, 15070, 11835, 11750, 9915, laboratory grade protection 200.95 9515, 9410, 7325, 6175, 6120, 5975 7:30-12:00 p.m. 0030-0500 HCJB, Ecuador 15155, 9745 7:50-8:15 p.m. 0050-0115 Vatican Radio 11845, 9605, 6015 8:00-8:20 p.m. 0100-0120 RAI, Italy 11800, 9575 L Electronic Specialists, Inc. 8:00-8:25 p.m. 0100-0125 Kot Israel 11655, 9815, 7410 171 S. Main St., Box 389, Natick, MA 01 760 8:00-8:30 p.m. 0100-0130 R. Argentina 15345, 11710 (not Mon.) 8:00-8:30 p.m. 0100-0130 R. Japan 17755 Toll Free Order Desk 1 -800- 225 -4876 8:00-8:30 p.m. (+) 0100-0130 R. Budapest 17710, 15220, 11910, 9835, 9585, 6025 (not Mon.) MasterCard, VISA, American Express 8:00-8:30 p.m. 0100 -0130 La Voz de la Mosquitia, 4910 Honduras 8:00-9:00 p.m. 0100 -0200 R. Canada International 9755, 5960 (Tue.-Sat.) Circle No. 51 on Free Information Card 8:00-8:50 p.m. 0100 -0150 V. of Germany 15105, 11865, 9590, 9565, 9545, 6145, 6085, 6040 8:00-8:55 p.m. 0100 -0155 R. Prague 11990, 11970, 9740, 9630, 9540 7345, 6015, 5930 8:00-8:55 p.m. 0100 -0155 R. Beijing 17855, 15120 8:00-9:00 p.m. 0100 -0200 V. of China 17890, 15345, 11825 8:00-9:00 p.m. 0100 -0200 V. of Nicaragua 5950 8:00-9:00 p.m. 0100 -0200 R. Zinica, Nicaragua 6120 (variable; Tue. -Sat.) FROM (time varies) 8:00-9:00 p.m. 0100 -0200 VOA 21460, 17735, 7205, 6873 -USB 8:00-9:00 p.m. 0100 -0200 AFRTS, Los Angeles 25615, 21570, 15430, 15330, 11790, 6030 8:00-10:00 p.m. 0100-0300 WRNO, New Orleans 9705 (not all Eng.) ANTENNAS 8:00-10:30 p.m. 0100-0330 R. Australia 21740 ACCESBORIES.I 8:00-11:50 p.m. 0100-0450 R. Habana Cuba 17735, 9525 8:20 p.m.-12:10 a.m.0120-0510 R. Belize 3285, 834 HERE'S A TIP 8:30-8:40 p.m. 0130-0140 V. of Greece 11645, 9865, 9420 (not Sunday) 8:30-8:57 p.m. 0130-0157 Austrian Radio 9770, 5945 THAT'S PERFECT! 8:30-8:55 p.m. 0130-0155 R. Tirana 9750, 7120 8:30-9:00 p.m. 0130-0200 R. Moscow 17700, 15425, 12010, 11780, 11770, AM /FM AUTO RADIO 9710, 9700, 9610 ' 8:30:-9:15 p.m. (+) 0130-0215 R. Berlin International 11975, 9730 AND CB 8:30-9:30 p.m. 0130-0230 R. Japan 21640, 21610, 17825, 15195 8:30-10:30 p.m. 0130-0330 AWR, Guatemala 6090, 12180, 18270, 24360, 30450 8:45-9:15 p.m. 0145-0215 Swiss R. International 15305, 11715, 9725, 6135 9:00-9:25 p.m. 0200-0225 Kol Israel 12025, 11655, 9815 `Firestik'li 9:00-9:30 p.m. 0200-0230 R. Canada International 9755, 5960 (Sun. & Mon. also 15190, 11845, 9535) 9:00-9:30 p.m. (+) 0200-0230 R. Budapest 17710, 15220, 11910, 9835, 9585, GOLDEN SERIES 6025 9:00-9:30 p.m. (+) 0200-0230 R. Kiev 17900, 17860, 15180, 11770, 11720 9:00-9:40 p.m. 0200-0240 R. Polonia 15120, 11815, 9525, 7270, 7145, BARE -HANDS TUNABLE 6135, 6095 (length varies) "NO TOOLS NEEDED" 9:00-9:55 p.m. 0200-0255 R. Bucharest 11940, 11810, 9690, 9570, 9550 6155, 5990 HIGH PERFORMANCE ANTENNAS 9:00-9:55 p.m. 0200 -0255 R. Beijing 15120 9:00-9:57 p.m. 0200 -0257 R. RSA 9615, 6020, 5980 9:00-10:00 p.m. 0200 -0300 VOA 21460, 17735, 7205, 6873 -USB ALSO ANTENNAS FOR 9:00-10:00 p.m. 0200 -0300 R. Moscow 17700, 15425, 12010, 11780, 11770 CORDLESS TELEPHONES 9700, 9610 9:00-10:00 p.m. 0200 -0300 R. Nacional, Brazil 17830, 15290 MONITOR SCANNERS 9:00-10:00 p.m. 0200 -0300 R. Korea 11575, 11810 9:00-10:00 p.m. 0200 -0300 V. of Free China 11740 (via WYFR) 9:00-10:30 p.m. 0200 -0330 R. Cairo 12000, 9475 Dealer & Distributor Inquiries Invited 9:00-11:00 p.m. 0200 -0400 VOA to Latin America 17640, 15205, 9650, 6130, 5995. SEND FOR FREE CATALOG 1580 AFRTS, Los Angeles 21570, 17765, 11790, 6030 9:00-11:30 p.m. 0200 -0430 'Fimatlk' Antenna Company p.m. 0200 -0500 R. Australia 17795 9:00-12:00 2614 East Adams.Phoemx, AZ 85034 9:15-9:30 p.m. 0215 -0230 UN Radio 15435, 10869-SSB, 10454-SSB, 6190 (Sat.) Name 9:30-9:45 p.m. 0230-0245 R. Pakistan 21470,21595,17840 9:30-9:55 p.m. 0230-0255 R. Tirana 9750, 7120 Street p.m. 0230-0300 RAE, Argentina 15345, 11710, 6060 (not Mon.) 9:30-10:00 City 9:30-10:00 p.m. 0230-0300 R. Sweden 11705, 15420, 17840.558 9:30-10:00 p.m. 0230-0300 R. Lebanon 11955t State Zip International 11975, 11890, 11840, 9560 9:30-10:15 p.m. (+)0230-0315 R. Berlín Serving the CB and R. Nederland 9590, 6185 (Mon. 0230 -0320) 9:30-10:25 p.m. 0230-0325 Communications Market Since 1962. 5YEAR REPLACEMENT WARRANTY August1983 Circle No. 26 on Free Information. Card

www.americanradiohistory.comAmericanRadioHistory.Com CALCULATOR SAVINGS

En 11 P PACKARD ll::.oa

HP -10C Scientific $57.99 HP -11C Programmable .. 74.99 HP -12C Financial 99.99 ENGLISH BROADCASTS HP -15C Programmable .. 99.99 HP -16C Hexadecimal ... 9989 HP -41C Alpha Prog 149.99 82161A Cassette Drive !347.99 9:30-10:30 p.m. 0230 -0330 BBC A (15070 from 0300) 11750, 9915, HP-41CV Full Memory 20799 82162A HP-IL Printer .. 347.99 9515, 9410, 7325, 6175, HP-41 System Case .... 79.99 62163A Video Interface 169.99 6120, 5975 Port -X- Tender to 10 pts 146.99 82169A HP-I8 Interface.. 349.99 9:51 -9:58 p.m. 1 +) 0251 -0258 V. of Yerevan B 17900, 17870, 15180 149.99 62180A Extnd Functns 59.99 82104A Card Reader 10:00-10:25 0300 -0325 R. Polonia C 15120, 11815, 9525, 7270, 7145, Memory 59.99 p.m. 82143A Printer 26899 82181A Extnd 6135, 6095 (length varies) 62153A Wand 82182A Time Module ., 59.99 C HP -75C Computer 739,99 82183A Extnd 1!0 59.99 10:00-10:25 p.m. 0300 -0325 R. Mexico 17765, 15430, 11770, 9705, 5980 82700A 6K Mem for 75C 14899 62184A Plotter ROM 59.99 (Sun.) 62160A HP -IL Module 94.99 HP -97 Desk Progrmble 599.99 10:00-10:30 p.m. (+)0300-0330 R. Budapest B 17710, 15220, 11910, 9835, Call fer law Pdea on all Acm aorla and Software 9585, 6P25 (Mon; 0300 -0312 Wed. & Sat.) Tae Instrumena 99/4A Computer S149.99 $50 TI 10:00-10:30 p.m. 0300 -0330 R. Japan C 17755 Extended BASIC Module 74.99 10:00-10:30 p.m. ( )0300 -0330 R. Canada International A 9755, 5960 Peripheral Expansion Box 189.99 REBATE 10:00-10:30 p.m. 0300 -0330 R. Portugal B 11925, 9765 Disk Controller Card 189.99 10:00-10:30 p.m. 0300 -0330 R. Australia to Antarctica C 17750 (Fri.) Disk Drive 294.99 Expansion Box 10:00-10:50 p.m. 0300 -0350 V. of Free China C 17800, 15345, 11825 199.99 Compact Computer 40 ON 99/4A 10:00-10:55 p.m. 0300 -0355 R. Prague B 11990, 11970, 9740, 9630, 9540, 011vo Praxis 35 Triple -pitch Electronic Typewriter.... $349.99 7345, 6015, 5930 10:00-10:55 p.m. 0300 -0355 R. Beijing B 17855, 17680, 15520 PC -1250 Pocket Extended BASIC Computer $89.99 Sharp 10:00-11:00 0300 -0400 VOA A 21460, 17740, 9670, 7200, 6040 CE -125 Printer / Microcassette for PC -1250 149.99 p.m. C 5055, (Mon. 0235 -0435) PC -1500 Advanced Handheld Computer 179.99 10:00-11:00 p.m. 0300 -0400 TIFC Costa Rica CE -150 Cassette Intrfci 4 -color Printer-Plotter 179.99 10:00-11:00 p.m. 0300 -0400 V. of Free China A 5985 (via WYFR) CE -151 4K Memory Expansion for PC-1500 49.99 10:00-11:00 p.m. 0300 -0400 R. Baghdad D Some of: 21585, 15400, 11935, CE -155 8K Memory Expansion for PC-1500 104.99 9745 CE -158 RS-232C 6 Parallel Interface for PC -1500 179.99 10:00-11:00 p.m. 0300 -0400 HRVC, Honduras B 4820 (Mon.) CE -159 8K Memory Expans with Battery Back -up 139.99 10:00-11:00 p.m. 0300 -0400 R. Uganda B 15325 (irregular) 10:00-11:00 p.m. 0300 -0400 V. of Turkey B 17760, 11740 Cule FX -702P Handheld Computer, 1680 Steps $99.99 10:00-11:26 p.m. 0300 -0426 R. RSA C 9585, 7270, 5980, 4990, 3230 FA -2 Cassette Interface for FX -702P 39.99 10:00-11:30 p.m. 0300 -0430 VOA to Africa A 15752 -USB, 15240, 15185, 15175, FP -10 Printer for FX -702P 59.99 10877.5 -USB, 10869 -USB, 7280, FX -602P Alphanumeric Programmable. 512 Steps . 69.99 6035 MT -45 Keyboard with Chords, Bass, Rhythms 159.99 A MT -65 Home Entertainment Keyboard 249.99 10:00 -12:00 p.m. 0300 -0500 WRNO, New Orleans 6185 (not all Eng.) MT -70 Advanced Memory Keyboard 299.99 10:00 p.m.-2:00 a( +) 0300 -0700 R. Moscow A 17900, 15425, 15180, 15100, CT -701 Advanced Electronic Memory Organ 599.99 (12050 from 0330; 11750 and Call us for low prices on famous Casio digital watches) 11710 from 0530) 10:25 p.m.-fade 0325- R. One, Zimbabwe C (exc. Sun.) Paarl- 5904 Two -speed. Two -hour Recorder $49.99 3396 ardor 5901 Two -speed, Two -hour. Tape Counter 99.99 10:30-10:55 p.m. 0330-0355 R. Tirana B 7300, 6200 S801 Two -speed, Compact, Memory Hewind 14899 10:30-10:57 p.m. 0330-0357 Austrian Radio C 9770, 5945 X -01 Ultra -thin All Electronic 99.99 10:30-11:00 p.m. 0330-0400 U.A.E. Radio, Dubai B 17775, 15300 (length varies) SR -11 FM Stereo Microcassette w /Headphones .. 99.99 10:30-11:30 p.m. 0330-0430 R. Cultural, Guatemala B 3300 (Mon. 0030 -) Olympus Pearlcorder Microcassettes 10 for 24.99 10:30-11:30 p.m. 0330-0430 BBC C 15070, 12095, 9410, 6175, 5975 Use osMw'a check. postal money arder. VISA. or tAlC Prenl decks take N. wens 10:30 p.m.-1:00 a.m. 0330-0600 R. Habana Cuba A 11760,17735 to caw. Ada neon, 1 %0l your order p3ww n xuml Ent of Mtap ev extra s15e 10:40-10:47 p.m. 0340-0347 V. of Greece B 11645, 9865, 9420 (not Sun.) res to ekes CA aap e% subiect avalleminy USA 10:50-11:10 p.m. 0350-0410 RAI, Italy B 17795, 15330, 11905 ORDER 800- 421 -5188 outside 11:00-11:30 p.m. 0400-0430 R. Bucharest C 11940, 11810, 9690, 9570, 9550, TOLL -FREE CA, AK. HI Inbrmalen line 12131833-3282 6155, 5990 Tam's Inc, Dept CE -8 11:00-11:30 p.m. 0400-0430 R. Norway C 15175, 11870, 9610 (Mon.) 14932 Garfield Ave. 11:00-11:55 p.m. 0400-0455 R. Beijing B 17680, 15120 Paramount, CA 90723 11:00-12:00 p.m. 0400-0500 R. Sofia B 11860t tinetrue onnowAktwo (213) 633 -3262 11:00-12:00 p.m. 0400-0500 V. of Nicaragua B 5950 11:00-12:00 p.m. 0400-0500 R. Australia B 21680, 21650, 17795, 15320, 15160 Circle No. 42 on Free Information Card 11:00-12:00 p.m. 0400-0500 FEBA, Seychelles C 11800, 15200 (Sat. & Sun.) 11:00 p.m.-1:00 a.m.0400-0600 VOA A 15205, 9670, 7200, 6040, 5995 11:00 p.m.-1:00 a.m.0400-0600 TWR, Bonaire A 9535, 800 (length varies) 11:15 p.m.-11:30 p.m.0415-0430 R. France Inc. B 7135, 11735, 11875 11:30-11:57 p.m. 0430-0457 Austrian R. B 15165, 11665 11:30-12:00 p.m. 0430-0500 VOA to Africa A 15752 -USB, 15240, 15185, 15175, 10869 -USB, 7280, 6035 11:30-12:00 p.m. 0430-0500 Swiss R. International B 11715, 9725 11:30-12:00 p.m. 0430-0500 RAE Argentina C 15345, 11710, 6060 (not Mon.) 11:30 p.m.-12:45 a.m.0430-0545 BBC A 15070, 12095, 9510, 9410, 7160, 6175, 5975 11:30 p.m.-1:00 a.m.0430-0600 AFRTS, Los Angeles A 11790, 15330, 6030 11:30 p.m.-1:30 a.m.0430-0630 TWR, Swaziland C 7925, 3200 11:45-12:00 p.m. (+)0445-0500 R. France International B 9795, 11735, 11875 11:55 p.m.-3:00 a.m.0455-0800 V. of Nigeria B 15185, 15120 12:00-12:15 a.m. 0500-0515 Kol Israel B 21710, 15585, 12025, 15105, 9815, 12:00-12:20 a.m. (+)0500-0520 Vatican Radio C 6185, 9645, 11725, 15190 CONVERTERS 12:00-12:30 a.m. 0500-0530 R. Japan C 15300 12:00-12:30 a.m. 0500-0530 R. Norway C 17840, 15175, 11870 (Mon.) 12:00-12:45 a.m. 0500-0545 R. Nationale, Cameroon$ C 9745 , 12:00-12:50 a.m. 0500-0550 V. of Germany A 11905, 11705, 9690, 9545, 5960 Largest Selection 12:00-1:00 a.m. 0500-0600 R. Korea C 15575, 11820, 11810 of Equipment Available 12:00 -1:00 a.m. 0500 -0600 R. Australia C 21680, 17870, 17725, 15240, 15160 12:00 -1:00 a.m. 0500 -0600 VOA A 15752 -USB, 15345, 15185, $ Buy Warehouse Direct & Save $ 10869- USO,7280, 8035 12:00-2:00 a.m. 0500-0700 HCJB Ecuador B 11910, 9745, 6095 12:00-3:00 a.m. 0500-0800 R. Kuwait C 15345 12:00-3:00 a.m. 0500-0800 R. Nigeria, Kaduna B 4770 (not all Eng.) 12:30-12:40 p.m. 0530-0540 R. Garoua, Cameroon C 5010 36 channel 12:00-5:00 a.m. 0500-1000 WRNO, New Orleans A 6185 (Sun) (not all Eng.) 1230-100 a.m. 0530-0600 R. Portugal A 9575, 6075t converter 12:30-fade 0530- R. Ghana C 3366 (4915 from 0600) 12:30-1:15 a.m. (+) 0530-0615 R. Berlin International B 11890, 9560 $4595 12:30-1:25 a.m. 0530-0625 R. Nederland A 9715, 6165 (Mon. 0530 -0620) 12:30-1:30 a.m. 0530 -0630 Spanish Foreign R. B 11880, 9630 12:45-1:00 a.m. 0545 -0600 UN Radio B 15105, 11740 (Sat.) 12:45-2:30 a.m. 0545 -0730 BBC B 15070, 11955, 9640, 9510, 9410, 36 channel 7150, 6175 12:55-3:25 a.m. 0555 -0825 V. of Malaysia C 15295. 12350, 9750 wired remote 1:00-1:30 a.m. 0600 -0630 V. of Germany C 17875, 15275, 11905, 11785, 9700 1:00-1:30 a.m. 0600 -0630 R. Australia C 21680, 17795, 17755, 15160, 9570 converter 1:00-2:00 a.m. 0600 -0700 AFRTS, Los Angeles B 17765, 15330, 11790, 6030 only 1:00-2:00 a.m. 0600 -0700 VOA A 15205, 9670, 7325, 7200, 6060, 6040, 5995 $8895 1:00 -2:30 a.m. 0600 -0730 R. Kiribati C 16433 -SSB (not all English) 1:00 -2:30 a.m. 0600 -0730 Solomon 151. C 9545 (time varies) (not all English) r' Broadcasting 1:00.2:30 a.m. 0600 -0730 VOA to Africa A 15752 -USB, 15345, 15330, 11915, Send $2 for complete catalog 10869 -USB, 9530, 7280, 6125, 6080, 6035 of converters and equipment 1:00 -3:00 a.m. 0600 -0800 WYFR A 15130, 11805, 9680 1:00 -4:00 a.m. 0600 -0900 R. Cook Islands D 11760, or 9695 or 5045 Ouanln} Uleuum. \lea tita ier ( hargt' (not all Eng.) Add 5°'n shipping -\1101 rr +ldeIII add 4°'o labs as 1:10-2:10 a.m. 0610 -0710 V. of Free China A 5985, via WYFR 1:15-1:30 a.m. 0615 -0630 R. Canada International B 11960, 11825, 11775, 9760, 6140 (Mon -Fri) 1:25-3:40 a.m. ( +) 0625 -0840 TWR, Monte Carlo B 9492.5 (Sun. 0625 -1000) C &D Electronics, Inc. 1:30 -1:45 a.m. 0630 -0645 RTVC, Congo C 9715 (Mon. -Fri.) (irr.) P.O. Box 21, Jenison, MI 49428 (616) 669-2440 Computers & Electronics

www.americanradiohistory.comAmericanRadioHistory.Com anaZinG DEVICES 1:30 -2:00 a m. 0630 -0700 R. Australia RUBY B 21680, 17870, 17725, 15240, 15160, LASER RAY GUN - Intense visible red beam, burns and 15115, 9570 welds the hardest metals. HAZARDOUS device. Kits available. 30-2:00 a m. 0630-0700 Radio Polonia B 9675, 7270 RU83 PLANS includes part sources $15.00 1:30-2:30 a..m. 0630-0730 R. RSA C 17780, 15220, 11900 CARBON DIOXIDE BURNING AND CUTTING LASER produces 1:30-2:00 a m. 0630-0800 R. - Habana Cuba A 11725 a continuous beam of energy, HAZARDOUS device Kits avail- 1:45-2:00 a m. 0645-0700 R. Canada International able - B 11960, 11825, 11775, 9760, 6140 LC5 PLANS . includes part sources $15.00 (Mon. -Fri.) VISIBLE LASER LIGHT GUN produces intense red for 1:57 -4:55 aim. - beam 0657 -0955 V. of Philippines C 9578 (not all English) special effects and other various optical applications. Hand -held 2:00 -2:15 a.m. 0700 -0715 R. Japan C 15300, (15235 via enclosure houses batteries. Portugal) LGU3 PLANS $10.00 LGU3K KIT /PLANS (minus tube) $99.50 2:00-2:20 a.m. 0700-0720 R. Nederland IR C 21480, 15560, 11930, 9895 PULSED LASER RIFLE - produces 15-30 watt pulses at 2:00-2:30 a.m. 0700-0730 Swiss Radio International C 21520, 15305, 9560, 9535, 9000A at 200-2000 per second. 2:00-3:00 a.m. 0700-0800 ELWA, Liberia C 11830 LRG3 PLANS $10.00 LRG3K KIT/PLANS (minus diode 15119.50 2:00-3:00 a.m. 0700-0800 V. of Vietnam C 9840 BEGINNER POCKET LASER visible red simulated 2:00-3:30 - device pro- a.m. 0700-0830 HCJB, Ecuador C 11835t, 9720t duces an excellent monochromatic source of light 2:00-4:00 a.m. 0700-0900 R. Australia B 15115, 12290 -SSB (9570 to 0800) LHC2 PLANS $5.00 LHC2K KIT /PLANS $24.50 2:00-6:00 a.m. 0700-1100 HCJB, Ecuador C HIGH 11925, 6130, (9745, 0700 -1030) ENERGY VARIABLE AND PROGRAMMABLE PAIN FIELD 2:10-2:15 am. 0710-0715 UN Radio A 17815, 15195, 11875, 9555 (Sat.) p GENERATORS. REQUIRE NO CONTACT - Recently developed 2:30-3:25 a-m. 0730-0825 R. Nederland B 9770, 9715 device produces directional fields of moderate to high 2:30-4:00 a.m. 0730-0900 BBC H SPL capa- B 15070, 11955, 9640, 9510 ble of producing intense pain and discomfort HAZARDOUS 2:30-6:30 a.m. 0730-1130 Solomon Isl. Broadcasting IF C 5020 (not all Eng.) NOT USED WITH DISCRETION. SOLD FOR ANIMAL 2:30-9:00 (-) A CONTROL - am. 0730-1402 ABC Melbourne C 9680 MAY BE USED IN 2:30 CERTAIN INSTANCES TO DISCOURAGE UN- a.m.-fade 0730- Action Radio, Guyana C 5950 S WANTED ENCOUNTERS 2:45-4:30 a.m. 0745-0930 KTWR, Guam B 11840 o PPF1PROD /VAR PLANS $15.00 PPF1K KIT/PLANS $175.00 3:00-3:15 am. (+) 0800-0815 AWR, Portugal C 9760 (Sun.) PSP3 VAR HAND -HELD PLANS $7.00 PSP3K KIT /PLANS $44.50 3:00-3:15 a.m. 0800-0815 UN Radio A 17860, 15235, R 15120,11740 (Sat.) PHASOR BURNING 3:15-3:30 a.m. 0815-0830 R. Vanuatu D 7260, 3945 WAND - capable of burning flesh. gener- S ates 3500 volts of continuous DC power. 3:30-4:25 a.m. 0830-0925 R. Nederland B 9715 PSW3 PLANS 58.00 PSW3K 3:30-5:00 am. 0830-1000 FEBC, Philippines C 11890 KIT/PLANS $59.50 PARALYZING SHOCKING WAND 3:30-7:15 a.m. (-) 0830-1215 R. New Zealand C 15485, - produces 100,000 watt 9620 pulses of stunning power. 3:45-4:45 a.m. 0845-0945 R. Japan C 15235, 11875 PG1W PLANS . $10.00 PG1WK /PLANS 24 Hours 24 Hours CFRX, Toronto C 6070 KIT $79.50 Above electrical devices are hand 24 Hours 24 Hours WWV, Colorado A-B 20000, 15000, 10000, -held and may be used for 5000, 2500 PERSONAL DEFENSE PER ¡SNOOPHONE - allows user to call his premises and listen ExplanatoryNotes. in without the phone ever ringing. SNP2 1. Times in first column 1 PLANS $7.00 SNP2K KIT /PLANS are CDT. For EDT add hour; MDT subtract 1 hour; PDT subtract 2 hours. Days of week $49.50 are in GMT. LONG RANGE WIRELESS MIKE - miniature device clearly transmits over 1 mile 2. Quality. A- Strong signal and very reliable reception. B- regular reception. occasional reception under fa- C- FBT9 PLANS vorable conditions. D- rarely audible. These ratings are for locations in the central USA. European and African $7.00 FBT9K KIT /PLANS... $34.50 WIRELESS TELEPHONE stations are in general, more reliably received in eastern North America. Asian and Pacific stations are more reli- TRANSMITTER - long range all auto- ably received in matic. undetectable. western North America. North American stations are received well except in areas too close to the transmittersite. VWPM5. PLANS.. $7.00 VWPM5K. KIT /PLANS .$34.50 3. The information TALK AND TELL clearly and in the listing is correct to press time. However, frequencies and schedules are constantly - automatically records both sides changing. Listen to "SWL Digest" on R. Canada International for late changes, of a telephone conversation when phone is being used Friday at 2240 Saturday at 2135; TAT2K. KIT/PLANS . Sunday at 1930; GMT Mondays at 0206; and to "World of Radio" on WRNO, GMT Sundays at 0230 and 2330. $14.50 TAT20 READY TO USE 524.50 4. Radio: V. R.- -Voice Our order phone is available 24 HOURS. frequent changes 7 DAYS A WEEK. t = W ite for FREE catalog of our many products. ( +) = time one hour later after DST period (Europe, last Sunday in Sept.; Soviet Union, Oct. 1; Canada and USA, We accept Master Charge or Visa Please last Sunday in Oct.) allow 10% for ship - ping On orders $50 00 WE PAY freightreight. ( -)= time one hour earlier during southern hemisphere DST (starting last Sunday in Oct.) SEND TO: SCIENTIFIC SYSTEMS DEPT 01. P O BOX 716 AMHERST, NH 03031 OR CALL FOR ORDERING ONLY 1-603-673-4730

FIRST QUALITY COMPONENTS atalog- - NOT MAIL ORDER "SECONDS" overd11o00 part

IC- KOOLERS- Isom Stock No Pine DIGITAL MULTIMETER i TI WIRE ARIES ZERO UNITRACK` dissipate No. In IC Pepe Single Diary swath opera TI LOW PROFILE over 2 w.ne wheat nom 22225 14 9.29 bon Large easy to read 5 .0, .,,q Sin WRAP INSERTION lon9r, 22228 18 .29 3 -' . digit display 800 hours SOCKETS bene' o operating FORCE Just wenle KooNron- 22227 18 .29 Ille wnh single 9v SOCKETS attery Seven Tin plated neat 22228 20 .29 ,unctions-- SOCKETS - and of IC ei°,e lop éx1He26W Volts DC Ann. Ohms Tin plated copper alloy wont shake ACC Volts AC Amos Gode i phosphor bronze 688 contact pins cam actuated, and Resistor Junction Aud- true zero $79.95 ible Conlinuity Checkl contact -3 wrap with gas tight seal. insertion - tin plated solder Stock 100 Stock 100 - tail pins - capable II of being 1 -99 -499 1 plugged No. No Pins 500 No. No Pins -24 25 -99 999 into dip sockets, 11201 including wire wrap. WILD ROVER 60/40 ROSIN 11301 e '9.40 5.36 S.30 a 5.10 5.09 5.08 CORE SOLDER 11302 14 .59 .54 .45 11202 14 .wit Tn Stock engin Weight .14 .13 .12 capsule 11303 le .64 11203 16 Stock No. of iy Orion is 005 witnout the No .a L fleet! for nuce .58 .48 .16 .15 .14 No. Pint 1-9 10 -49 50 11304 18 .73 .66 .55 11204 18 arm Extremely last on 50075 062 9 1 5 St 16 .18 .17 .15 ; A ered n6iSe 11305 20 11055 24 4 98 $4.35 53.90 eltwithlow Normally Open - 50076 062 25 a 239 .99 .90 .75 11205 20 .20 .18 .16 ,1056 20 5.15 4.50 4.05 ited 115 VAC. 16 amp-30 milliohm re. 11308 22 1.12 1.02 .85 11208 - 615 radius 160 50077 062 50 8 4 25 22 .22 .20 .18 11057 40 6 5.95 5.35 by thick 11307 24 8 50078 032 33 1 5 131 1.25 1.14 .95 11207 11058 64 12 02 10.50 9.45 Stock No. 1.9 10aUp 50079 032 88 5 a 11308 28 1.52 1.38 1.15 12098 51.42 $1.28 247 11208 28 .28 .26 .25 50080 032 175 . 8 457 11309 40 2.05 1.88 1.55 11209 40 .40 .37 .33 ELPAC POWER SUPPLIES - DC /DC CONVERTERS MODUTEC SINTEC ELPAC Input Output Output Dimensions Special of the Month! I Stock Ne No. Voltage Voltage Current (H.W50) Miniclamp AC Volt- Ammeter 300 MW Inne IVOCI IVDCI (NIA) in Inches Price / allows singling one conductor out of 13825 CB3801 30.7.0 12,0.6 025 .48x.5153.05 5 7.95 BREAKABLE many without disarrangement. 13828 CB3611 307.0 -12,0.6 0.25 . 48x.5153.05 7915 Stock No. AC Ansporns 13827 C83802 3.07.0 15.0 .7 020 .48x.5153.05 7.95 SOCKET STRIPS Price 13828 C83812 307.0 -15±0.7 0-20 .485.5153.05 7.95 WITH MACHINED / 13730 025/1 $39 50 13829 083804 3.0-7.0 2810.7 0-10 .48..51x3.05 7.95 SÑREE$ 13731 P50Á 39.50 Stock No. 13801 COLLET PINS! 13830 C83814 3.0-7.0 -28,01 010 .48x.5143.05 7 95 13732 P100Á 3950 - "Floppy Disc" 1 5 W TYPE: drips can be broken by hand Into . desired ACCESSORY LINE SPLITTER Power Supply For 13831 003801 407.0 12;0.6 125 051, .251.77 924.9S number of contact pins Solder fail version te»l ure, allows fast readings of AC - Winchester Drives 13832 CL3811 4.07.0 -12,0.8 125 .85151.251.77 24.95 gold collet /tin power con \r,, Stock No. sumptlon in - 13833 CL3802 4.0-7.0 1530.7 100 .65151.251.77 24.95 shell. wire wrap of Sale Prise of plug equipment with 13834 No. Pins Style Each out separation of leads. $109°° CL3812 4.0-7.0 -15,0.7 100 .651,1.251.77 24.95 features gold 13801 -1 Data Sheet 13835 CL3804 4.0-7.0 2801.4 50 651 x1251.77 24.95 10240 25 Solder tail $1.75 Stock No. 13727 $9.95 13838 CL3814 407.0 collet /gold shell 10241 tor13801 25 -28,1.4 50 651,1 .251.77 24.95 25 Wire wrap 3.25 13825 -1 DATA SHEET FOR DC /DC CONVERTERS 25 POCKET SIZED BATTERY TESTER ELPAC POWER for all types of small batteries lron' SUPPLIES- SOLV SERIES FULLY REGULATED PIN FORMING TOOL 1.35v to 4.5v Output puts IC's on their SINTEC FLPÑ output Current 111xwx01, y` íJ Stock No. 13733 $ 1 3.95 Stock Ho Pan Voltese Reline oVP Price true row to row yf y L- 3150 SolV15-5 ? OA Fixed included 539 95 spacing. One side is fr VOLT -I -CATOR 3603 SOLV15.12 Fixed ...eluded 39.95 automotive 13604 900/1515 15 1.2A Fixed included 39 95 for .300 centers, Flip tool over for devices diagnostic meter plugs 3606 SOLVli24 24 0.75A Fixed 3 995 on .600 -4C...4"" into lighter socket and indicates bat- lascle SOLV305 5 OVP4 5995 centers. Put device in tool and 13609 15 O.W tery condition and charging rates. SO1V3012 C A OVP41 59 95 squeeze. NEW! Stock No. 10200 SOLV3015 3.3A OVP4 5995 $14.95 13812 STATIC MODE _) Stock No. 13736 SOLV3024 24 2.04 s5/a.4a/6Aa/16 OVP4 59 95 ONE TOOL DOES (ANTI- $15,95 138021 NW Sheet for SOL/ Sense ix 8 thru 40 PINS! Stock No. 11059 $12.95 AC VOLTAGE TESTER OK MACHINE AND TOOL e plugs into any 110v service recept- Li IC INSERTION/ SOCKET WRAP 10 1J295 4t"" e acle to check line voltage over 50- IC DIP socket s plash //anis EXTRACTOR VAC EXTRACTION KIT 13297 IB pin r -- 150 Vink,ca 13296 DP le 20 pin One-piece, spring steel ccn- Stock No. 13735 95 wIhnumbe,edholesintons D One, Socket Polo...ro 14. eepin9hto c 1]]900 24 Vin struction. Will extract all LSI, MSI :u nbclan °n IC lad VOM- MULTITESTER o i 246 , and SSL devices with 8 to number 3- 24 function sum nopi7 versatile /em .n o Volt- Ohm -Milliammeter in el n9 i ,imn,. Pins- onny ana Stock No. small package s;-nq"° $37.74 in, $ 2.10 per pack 13313 Stock No. 13729 $13,95

We accept VISA. MC. Drawer Q Milford TOLL C.o D.. CHECK. or M.O. 800 -526 -5960 -INCLUDE SHIPPING CHARGES - Oto5100. -03. 00 SINTEC Co. NJ 08848-99 90 FREE in NJ (201) 996 -4093 :z 's3- Dó4 Circle No. 36 on Free Information Card

www.americanradiohistory.comAmericanRadioHistory.Com TIMEX 511-ICIó1r 1000 1

Powerful - fully programmable 2K memory Portable - 6ti" x 6 %" x 1?(" - 12 oz- Expandable - Optional 16K RAM module Single -key entry commands Educational Unique syntax -check report COMPUTER- PERIPHERAL SWITCHERS codes for error identity Accurate to 91/2 decimal places for full range math and MIME Connect any number al peripherals to a single I/O port - use a single printertosup- functions Graph drawing and flamant port several microcomputers - use two or more Diners to support a single scientific lm Advanced 4 -chip design & 2764 EPROM Programmer microcomputer - access a modem from any at several microcomputers - Idel animated display 2708,2716,2732 equipment The SelectoSwncnes are denIgned to portability and dmeUBMbg or compering combining power, EPROM PROGRAMMER eliminate the unnecessary plugging S unplugging of cabins which Conn «t printers. affordable price. JE664 you PIN terminals. or moderns to various computers. By using a SeIncldSwach, achieve 8K TO 64K EPROMS - 24 AND 28 PACKAGES more efficient system operation. deer utilization of peripherals & computer pons. TS1000 $54.95 eliminate redundant hardware & reduce service calls 5 yr limited warranty on all PROGRAMS 2716's IN 16 SECONDS- Selecto-Switches No power required Sue (Inches) COL x 73V a 314 21 lbs ACCESSORIES FOR I=E1 maimmiair 1000 and ZX81 -PROGRAMS 2764's IN 64 SECONDS - property Emuletes RS232 SERIAL SELECTO- SWITCH Expansion from 2Kto16K. size: 3.53- x1.5'(504 TS1016 $49.95 yy validates, KI 511"- ICIBIr 1016 Computer Interim editing/programr lading Loads dta of :1 or EPROMS RS232C expansion Switches all lines of asynchronous data Easy in RAM by keyboard Lads RAN from an 32 column thermal pnlnlnlalbaf TS2040 $99.95 into RAM by BEffbOard Changes dle serial ports Connectors are female DB25 type 2040 EPROM Comperes EPROMS tor content differences Copies EPROM. Power 4,- minclair Printen tpiolen l/lor orBdiW.-D PRICE N. TPP yah 1bo1n5 VACne 6 SwN/mow O W phw eb slump Encseu: PART NO. DESCRIPTION paper 3 rolls 1x.3 in x82 1 -3 $5.95 ® ls ld eId ma owconn c u 5 -05 x x 2 Switch $139.95 30).11 WI 5h. la. GRS232 -AB -Way Keyboard Mask for Your Keyboard GRS232 -ABC 3 -Way Switch $179.95 JE664 -A EPROM Programmer $995.00 ZX8111000 Computer JZX8111000Conversion Kit Assembied & Tested Includes JMI6A Module) DB25 PARALLEL SELECTO-SWITCH ( JE665 RS232C INTERFACE OPTION - the JE665 RS232C Interface KEYBOARD - TRS-80, Apple, and IBM compatible Switches 24 lines (line J... Option Implements computer access to to JE664's RAM sample software written in RIT MOUNTED IN DTE for TRS80' Model I. Level II Computer. Baud rate. 9600 Word 1 is ground) Connectors are female OB25 type ENCLOSURE LIONT BASIC provided PANELS WITI Lgth 8 Oils Odd panty Stop bits 2 Option may be adapted to other computers PART NO DESCRIPTION PRICE T. -ARS EPROM Pa& w /JEe65 Wan $1195.00 2 $139.95 JE664 GP24 -AB -Way Switch Assembled and Tested JM16A Module) Install In seconds Mtn. (Includes GP24 -ABC 3 -Way Switch $179.95 .1.1. packing hem ms. TM JE667 Ait poprid. ...mot Ins 7sEil IOC EPROM JUMPER MODULES - the JE664'S JUMPER MODULE (Persoah- And pls. smolmiriseard he 662 ty Module) is a plug-in Module that presets .1E664 for proper programming pulses to ea. sits CENTRONICS -STYLE SELECTO -SWITCH he EPROM & configures EPROM socket connections for that antullan EPROM meruwe On m.n- mils Craw lines are female Centronics a «" Switches all 36 Connectors use ti JEW Pont DESCRIPTION PRICE No. EPROM EPROM MANUFACTURER PRICE PART NO. vmwiM she nmnlawi 1E661 KEYBOARD MASK PTE JMOBA 2708 AMD,Molorea. Natvnal. Intel. Ti sta On -AB 2 -Way switch $199.95 The JEW Keyboard Mask users of the GCENT provides MINA 27101451516 Intel,Motorota.Nalloal.NEC,TI Sra 95 zxe1I1000 series computer the individual feel of GCENT -ABC 3 -Way Switch $229.95 JM168 nesPll6 Motorola. Tl 145, 12, +12) Eta 95 Koch keypad On the keyboard. The mask has a MIS JM32A TM52532 Motorola. Ti sta 95 ea outline around each keypad Snowing the user to JE682 -AK Keyboard Conversion Kit 599.9584. JM328 2732 ANO.F )Isu. NEC. Hllachl.lniel 61495 feei and correctly positron their tinders onto the mTN PTE. CASE AS MCTVREO, keyboard JM32C 2732Á(21V) New, Intel 011 95 \ Keyboard Conversion Kit 059.95 ea. JM64A MCM68764 Micro -Logic Corp. B6'5 JE681 KEYBOARD MASK 59.95 each Jrwe ouT MC14681364 Motorola 514 95 JM64B 2764 Intel sto 9s MICRO- CHARTS ZI31/1000 is a trademark of Sinclair /Rena JM6aC rebosA4 Ti 514 95 JM6m H540271404 HMCrk (2101 51495 80 -Key Keyboard Fully decoded data Instant access 2sided, totally comprehensive Compan Perfect for programmers 6 engineers CONTROL DATA KEYBOARDS iii's Black Hole 81/2 x It !n. durable credit card ptastic Clear & anise tables for lull lnsbrucba sot. disassembly, ASCU, base conve, * 7-bit Parallel ASCII Eraser cycle times. EPROM Óa. effect of lags compare vs. lump. Interrupt structure. pleat grams, bug notes. & much more.. * SPST Switching 9 Chips - 8 Minutes PRICE PART NO, REFERENCE FTZ Shielded Base * The Black INN EPROM Ease/ well completely and sally erase 9 EPROMS In ass than ML -Z80 Z80 CPU $5.95 featuring N -Key Rollover e minuta. The Back Hole Is a fully automatic cassette loading eraser ML -8080A 8080A/8085A $5.95 U -shaped 4000 hr. 1.10 lamps mounted in a special AIIAK (UV reflectivity of 9) ML -6502 6502 (65XX) $5.95 * 128 Character ASCII parabolic light tunnel. In operation, The user slips In an antistatic two Boa 13 a ML- 8048 8048, Relatives, Algorithms $5.95 Incl.) containing the EPROMs to be erased into la loading slot on the Iront panel of CA150C $69.95 * Non -Slip, Non -Glare Keycaps Black Hob The rat is bully automatic The Black Hole latches no Bug B0 Into ML -7400 540017400 TTL $5 95 Integration * CDC752 Terminal Keyboards place. turns on the UV lamps and sum Its fully saki stale (CM05) UV 95 -Key Keyboard done timer. The percentage erasure time is monitored and displayed on a bort panel A Attractive Case LEO readout AI the end of the erase cycle, the Black Hole elects the Bug Box con- BOOKS taining the 9 erased EPROMS and turns on power. These Control Data Keyboards consist of a base, cover. PART NO. PRICE 30001 National CMOS Clete Book (1981) 56.95 74C. CD4000, and AID Converters the keyboard assembly, and an interface cable. Color (640 pages) ULV.008 Replacement Lamp for ERS-0oe . ...$29.95 (case): Harvest gold and black. Color (keycaps): Black, National Linear Data Book (1982) 81185 Eraser, Auto Eject te LED Readout $249.95 30003 blue, and red. Electrical requirements: +5V 600mA. ERS-008 (1376 pages) LM. LF, ADC, DAC, LH Series -12V Ca 50mA. Size: 211/2 "W x 9 "D x 31/2"H. Weight: 6 06.95 MEMORY EXPANSION KIT 30006 National Memory Data Book (1980) lbs. All untts brand new in original boxes, specifications IBM (484 pages) RAMS, ROMO, PROMS. EPROMS Series CA154A $79.95 included. SAVE HUNDREDS OF $$$ BY UPGRADING 30009 !Modell Data Book (1993) 09 95 (1356 pages) Complete line. MEMORY BOARDS YOURSELF! Keytronics 90 -Key Soft -Programmable Keyboard Most of IM popular memory boards allow you to add an additional (1980) 95.95 KEYLOCK SWITCH 30019 National Audio/Radio Handbook WITH SECURITY 64K. 128K, 192K, or 256K. The 19 ,06015 Kit will populate these boards (240 pages) Pre -Amps, AM. FM & FM Stereo. Power Amps In 64K byte Increments. The kit Is simple to Install - lust Insert the Handbook (1980) 915.95 nine &4K RAM chips In the provided sockets and set the two groups 30011 National Linear Application RFI shielded Notes, Linear Briefs, etc. switches. Directions ere included. 1736 pages) Application Cursor controls of Numeric keyboard 30012 National PAL Data Book (1982) 55.85 IBM64K (Nine 200ns 54K RAMs) $59,95 (176 pages) Application Note., Linear Briefs, etc. obit Parellsl Capacitance keys MEMORY 30013 Zllo9 Data Book (1983) 07.95 10 user -programmable keys EXPAND YOUR (841 pages) Microprocessors and Support Chips Positive TTL Logic Size: 171. x 81/4 'W x 2.14 TRS -80 to 16K, 32K, or 48K 210830 Intel Memory Components Handbook (1863) 514.95 Model 1 = From 4K to 16K Requires (1) One Kit (798 pages) Contains all Application Notes, Article Model 3 = From 4K to 48K Requires (3) Three KKs Reprints, Data Sheets. and other design Information Color = From 4K to 16K Requires (1) One KU on Intel's RAMO, EPROM5. E'PROMe 8 Bubble Memories. Made for Visual Technology, this keyboard features a sect, ily "eylock (includes two keys) to guard against re- 1 equipped ens Expansion Bard up la 405 Two Kits Required an b b.key numeric keypad; cursor controle; and 10 ueeprogrammable keys. Electrical Med0 Peripheral Handbook (l9e3 unauthorized use; 210a44 Intel Mkvprocessor & )...514.95 quirements: +5VDC. Color Black. Complete with case, keyboard assembly. - One KK Required for each 16K al Ecanelon - pages) Dala Sheets on all of (1027 Contains 150500:et het . color (keycaps): nts: for & Ill Intel's Micesnroceaeors and Peripherals. each TRS -16K3 200ns Color Model 512.95 Part No. KB270 $79.95 TRS 250ns for Model I S10,95 ATARI -16K4 MICRO SWITCH 85 -KEY KEYBOARD TRS -80 Color 32K or 64K Conversion Kit Keyboard Word Processing Keyboard, 26 Pin Edge Card Connection Supply Weepy 45000. Main B ea. 4164.2 84K ATARI PADDLES is OwERTY Additional Key Pads for Cursor and word processing lunebns Easy to install kit comes complete with (20Ons) dynamic RAMs 6 conversion documentation. Converts TRSaa color 23 "Lx5,"W x 1 3ri3"H Part No. 85SD1e -1 $29.95 each JSP (2) $4.95 pair computers with E circuit boards, & all new color computers to 32K. memory will the use of all the &41( of HI -TEK 14 -KEY NUMERIC KEYPAD Minor modifications of 32K allow the dynamic RAM providing you have a FLEX DOS operating system. ATARI DRIVER SPST switching Cheraw! grey keycap. Mounted on printed circuit bard. TRS -64K2 $54.95 JSD(1) $2.95 ea. 3Ln31Vx1'/,"H Pad No. K -14 $9.95 each transaction rech POWER SUPPLY +5VDC Ld 1 51/4" Mini -Floppy Disk Drive TV GAME SWITCH Output +5VDC el. aAMPpREGULATED (Deck/beige) ncrosed loci FOR TRS90 MODEL I - COLOR COMPUTER RSV 3 bleck power cafe 6'A_Whít7.0 x 2WNH. WI. 3 lbs. Dee shets Cosmet. Features single or dada density Reading made'. FM r"' Used on Atari. 514.95 each Part No. PS51194S to ically blemished. 1004/0 sings MFM double density Seek tim 25msec track 12VDC ( 164 ow.. 5VDC POWER SUPPLY +5VDC O 3 AMP REGULATED oemml, back Power s0.6V) functional. 25011) 50 mW. 'Rotas* at rend Does not liO me. Input. 115VAC, 47 -44000 Output SVOC Adjustable v/ 3 amp. NVOC a 2.5 cep. Adlu lable cur- lee pow seeps. cables) 30pg data took lof Al 30/ Es. rent nob Ripple a Noise: 1MV rms. WV p 2 mounting sedates sel recognised. Slyer 4 "W x Size 544W 8-0 3'4-H TGS -1 ...$2.95 ea. 1'Ir -L x 24/16 "N wt. 2 Ibo. Oela shat included Part No. Limited Quantify! Price 411 Part No. UPS-1 $29.95 each l Thermometer Kit FD200 $179.95 J Digital POWER SUPPLY +5VDC iR 7.5 AMP, 12VDC O 1.5 AMP SWITCHING Single'slded, 40 tracks. 250K bytes capacity /power select owe tt Dual witch Input 115VAC, 50 -60HZ Cd 3 amp /230VAC, 50513 D1.6 amp. i.e veil. supply controls for indoor /outdoor Chas (115 /230VAC) Output: 5VDC at 1.6 amp. 12VDC R 1.6 amp. A lt. elit pow. cell. 11'h -'W x FD250 ...... $199.95 Double'sided. 3s hacks. 431K bytes capacity r dual monitoring - can be 130 "D s 34 "H. Wt 61es. Part No. P5941/05 $39.95 each extended to 500 feet. Con - Ilnuoue LED .8- ht. display. POWER SUPPLY 4- Channel Switching - Apple Compatible Range: .40 F to 199F, 401C FOR USE AS AN EXTERNAL POWER SUPPLY FOR APPLE 8" FLOPPY DISK DRIVE to 100C Accuracy xl Microprocessor, minleomputer, terminal. medical eq ipment and process control applications. in- nominal. Calibrate for 12VOC Cu. IA. put 90 130VAC 0.440Hz Output s SVOC A SA , -5VDC D IA- 12VDC A IA 1 501. main out 5 801R FahrenhelllCeislus Lim reo. 50.1%. Ripple 30 mV p.o Load reg - %. Overcurreol protection. 50 Shugart !Os. Simulated walnut case. AC putt 10X.6 3 /R -L v 1-7/8'10 x 1 15/16 H. WI. 11/2 k compatible II adapter Included Size. each Part No. FCS -604A $69.95 s Single -Sided By,'L a 37, 4H x 1y.10 J E300 $39.95 77 Tracks each Universal Computer Keyboard Enclosures $10.00 Minimum Order - U.S. Funds Only Spec Sheets - 30e 400/800K Bytes 61/2% Sales Tax Send $1.00 Postage for your "OTE" Bonk Desk-Top Enclosures California Residents Add 1 Capacity as designed for easy modifica. Shipping - Add 5% plus $1.50 Insurance FREE 1983 JAMECO CATALOG Industry Standard uddn cn mocha Prices Subsec to Change r linen Send S.A.S.E. for Monthly Sales Flyer! Mecca brown The FDDtOe-O e- Floppy Disk Dd. (industNrrlyy StandartlF1 features o Sliding rear/bottom panel for service/ Elecironios - Worldwide double access: TOp /bolet Mail Order .53 component anelso80- density. rT ertlrate: 256K bitsllsegc. single density) bi slusec 1200 finish (gold flot thickalum. aledine type double density. The FDD10o -8 Is designed to work with the single. e modification cola) ta best amt adhesion alter sided II sectored IBM Diskette I, or eq. disk cartridge Power. qn' bop & bottom for coding eiiciaicy Vented awls 115VAC a 50 -60Hz. a 24VDC W 1.7 amps max., o 5VDC W 1.2 ernes y Rigid construction provides unlimited aallablons MasterCard VISA' 3 ftlas, Unit as pictured above loons not include case, power supplyy, o b - J Assembly instructions included 4.a arreco cables). Size: 13.55.W s 14'L a 4.511. Weighs 12 lbs. Incl. 96pgt DTE -8 Panel Width 7.5" $24.95 ELECTRONICS title!. Pee No. Price -11 Panel Width 10.13" $27.95 DTE 1355 ROAD, BELMONT, CA 94002 DTE.14 Panel Width 13.5" $29.95 SHOREWAY FDD100 -8 . . $169.95 ea DTE -20 Panel Width 19.25" $34.95 8183 PHONE ORDERS WELCOME - (415) 592-8097 Telex: 176043 ) Circle No. 21 on Free Information Card Electronics 104 Computers &

www.americanradiohistory.comAmericanRadioHistory.Com TOLL FREE ORDERS 1 -800.826-5432 AK, HI, CA OR INFORMATION (21 3) 380-8000 QUALITY MINIATURE eqk, 13 VDC RELAY ACTIVE, YOUR 6 VDC RELAY *19'I ?itf CONTACT SP N C 10 AMP @ 120 VAC SUPER SMALL IM1! 1 SERVICE ENERGIZE COIL TO NUMBER ONE f.,J` RELAY. ' ¡C GOLD COBCOBALT OPEN CONTACT COIL: 13 VDC 650 OHMS AVAILABILITY CHOICE RATED 1 AMP AT 30 VDC: SPECIAL PRICE $1.00 EACH HIGHLY SENSITIVE, TTL DIRECT DRIVE POSSIBLE, KEY ASSEMBLY OPERATES FROM 4.3 TO 5 KEY 6 V, COIL RES. 220 OHM. :. $1.00 1 3/16" 13/32" 7/16" 4 EACH '''"`"4.- . _ AROMAT # RSD-EV CONTAINS . . Elect 5 SINGLE -POLE . $1.50 EACH NORMALLY OPEN SWITCHES ß" 10 FOR $13 50 MEASURES 3 3/4" LONG 6 KEY .I`" !''->t!1%A`ili,1`!iMti+Mri.il.`.i`` 120V INDICATOR $1.25 .,.+4+t gt..t .°J OD n -IC '- i1_1 1`I) EACH NEON INDICATOR. RATED CONTAINS 6 SINGLE -POLE 120 V 1/3 W. MOUNTS IN NORMALLY OPEN SWITCHES 5/16" HOLE ...RED LENS MEASURES 4 1/4" LONG 754 EACH 1+44 10 FOR $7 ree .Attar ad` 100 FOR $6500 L.E.D.'S STANDARD JUMBO wititter;d-lecgtg Fiirc p F ne s METERS DIFFUSED RED 10 FOR $1.50 1 MA GREEN 10 FOR $2.00 25/16" SQUARE 't YELLOW 10 FOR $2.00 Actives ewly PANEL METER e MOUNTS IN y p°°- A FLASHER LED Revised = 21/8" HOLE # 3 5 VOLT OPERATION -, $5.50 EACH RED JUMBO SIZE ut -lya $1.00 EACH Spri gl m er V.D.C. 0 - 15 BI POLAR LED C. /,+THIS 2 -1/4" 2 FOR $1 70 SQUARE METER LED HOLDERS MEASURES .'- TWO PIECE HOLDER Wh = ther ou're a serious hobby 111 0 15 FOR JUMBO LED a EACH 10 FOR 654 200 FOR $10.00 rime r, student or profess, POWER SUPPLY W/ PRE -AMP sho $dn't be without it. Call f THIS SUPPLY WAS USED TO POWER ur free copy today. /. AN 8 TRACK/CASSETTE UNIT. IT WILL SUPPLY APPROX. 18 VDC AND /:^ 1111 ¿ircie No 50 on free inforrnat.on card or write: "Xti , INCLUDES A SMALL PRE -AMP TO ¡f4 /,. BOOST SIGNAL LEVEL. P.O. ;Box 8000, Westboro, Mass. 171581 A`\. ?.. RCA PLUGS FOR LINE IN /OUT. $4.50 EACH CALL OLL FREE: 1- 800.343 -0874 . customers (617) 36e 0500 SEND FOR FREE 40 PAGE CATALOG ! call

COMPUTER TRANSFORMERS Circle No. 50 on Free Information Card 120 volt GRADE primaries 1- CAPACITORS II11111181I=1rMI 5.6 VOLTS at 750 MA $3.00 7 1700 mfd. 150 VDC $2 00 6 VOLTS at 150 MA $1.25 GET IBM -pc Capacity at a Fraction of Price! 2 1/2" DIA 4 3/4" HIGH IBM's ¡1 16.5 V. at 3 AMPS $6.50 3,600 mfd-mfd. ` 18 V it 650 MA $3.50 New NETRONICS 16 Bit EXPLORER Kit 400 $1.00 88 -PC 18 VOLTS it 1 AMP $4.50 1 3/8" DIA 3" HIGH Starts at Just -Accepts All IBM Perpherals. 18 V.C.T. at 2 AMP 6,400 mfd. $5.50 24 VOLTS at 250 MA the _ -IMI) $2.50 Its true! Now you can enjoy the power of O IBM compatible keyboard...5299.95 60 VDC $2.50 24 VCT it 1 AMP $4.50 Intel 8088 -the same microprocessor which + 10.00 phi. 1 3/8" DIA * 4 1/4" HIGH 42 ' V.C.T. at 1.2 AMP $4.50 powers the IBM-PC -and run any program corn. IBM compatible color board..4299.95 18,000 mfd. 75 VDC $4.00 S piled toi the IBM.PC...starting at only $399.95! + 10.00 pái. 2 1/2" DIA. + 4 1/2" HIGH 1 DC WALL O Additional ROM requiired...S35.00. O Special IBM compatible system: with key. 22,000 mfd. 15 VDC Take this easy, low cost way to learn 16 -bh: ' board, color graphics board, floppy disk 2- DIA . 2 1/2" HIGH $2.00 TRANSFORMER technology! Two-board system features: Set your own pace! Invest and warn, at the rate controller, 64K RAM, cabinet, standard' 22,000 mfd. 40 VDC 1. 8088 mother board with 5 -slot expansior YOU want! Add to your EXPLORER 88 -PC: power supply and a single 5'/4" floppy drive... - HIGH hardware designed Deluxe heavy-duty steel cabinet that houses 2" DIA. 6" $3.00 ALL ARE 115 VAC bus; accepts any fa either two 544" floppies or a 51/4" hard disk $1899.95 + 25.00 pái. 24,000 mfd. 30 VDC PLUG IN IBM -PC; and with one floppy. This cabinet features a 1 3/4" DIA. 4" HIGH $3.50 -- 2. 64K memory board. expandable to 256K, IBM compatible hard disks, built-in modern 31,000 mfd. 15 VDC with 18M compatible RS232 communica brush-finish front paiel and a wood -grained board, eprom burner. print buffer system plus ' 1 3/4" DIA 4" HIGH 82.50 colons port. sleeve. more will be available shortly. 4 72,000 mfd. 15 VDC VOC at 70 MA $2.50 O EXPLORER 88-PC Cabinet...:199.95 Any disk-operating system which works on the 2" DIA... 4" HIGH $3.50 9 VDC at 225 MA $3.00 + 18.00 obi. Over 100 EXCLUSIVE Products and Kits - IBM will work directly on the EXPLORER 88 -PC 180,000 mfd. 18.5 VAC at 10 VA $3.50 1 including the 'Speak Easy' universal voice at 6V 'and all programs compiled for the IBM will rur A heavy -duty open frame power supply 2 1/2" DIA 4 1/2" HIGH $1.50 17 VAC at 500 MA $4.00 with fan that can be used is your own ca.bi synthesizer, a Diagnostic card with built -in on it. logic for IBM-PC, terminals, moni. CLAMPS TO FIT CAPACITORS SOa .. 22 VDC at 60 MA $2.50 net or installed into the Netronics cabinet is probe the IThe system monitor ROM included in the Starter available as follows: tors, the ELF and EXPLORER 85 computers, system features a user -friendly operating system and much more, are described in our up- O 10 amp power supply for system + 2 flop - coming catalog. 0's yours FREE if you check MINIATURE TOGGLE SWITCHES that allows easy program generation and debug pies...$149,95 + 8.00 pái. ALL ARE RATED 5 AMPS 125 VAC 'ging. the commands include display /modify here @ DAs above + extra power for 1 hard disk... memory...display /modify registers...input/output $169.95 + 8.00 pái. For Canadian orders S.P.D.T. data to 1/0 ports...block moves...single -step S.P.D.T. S.P.D.T. OIBM compatible disk controler board. Con- please double the amount trace mode._go /run with optional breakpoirr (on -on) (on -on) (on- off -on) trols tour 51/4" floppy drives (w /2 deice of pái shown. IBM-PC is a SOLDER LUG 1. and reguter reports...cassette load /save with fl P C STYLE, _ SOLDER LUG cable). Available wired and tested only... registered trademark of NON -THREADED TERMINALS labels....plus a complete system test program TERMINALS $250.00 + 8.00 pá . IBM Corporation. $1.00 EACH 1..,-- BUSHING I $/ 00 EACH Ithat tests and reports condition of ROM, RAM, and BIOS source listings: available 10 FOR $900 Monitors 75s EACH 1 10 FOR cassette Interlace, timer, DMA controller, Inter 100 FOR $80.44 $900 on either disk or hard copy at S35.00. 10 FOR $100 lop FOR $8000 Irupt controller, and the communications port. Please speedy format and system required. I Mamitas:. These test programs not only allow easy debug INTEL 8086/8088 user manual...S15.00 t Iging of software but they serve as hardware and S.P.D.T. + 1.50 pái. S.P.D.T. / D.P.D.T. software learning tools. (on- off -on) (on -on) OTHE 8086 BOOK by RECSOR á ALEX... +j (on -on) The EXPLORER 88-PC STARTER KIT includes 4 $16.00 + 1.50 (Mi. "pái" stands tor "postage and insurance ". PC LUGS, . °. I 1 NON -THREADED 'mother board, memory/I/O board, al components THREADED 4,r`¡ SOLDER LUG BUSHING Co used, one 62.pin bus BUSHING 1 ©I TERMINALS needed, sockets tor I' CALL TDLL FREE 1.800 -243 -7428 for Charge Card Orders. PC STYLE '44 $0.F0 EACH 11 10. EACH connector and complete assembly/test instruc. 75t EACH In Conn., call 203-354-9375, Conn. res. add sales tax. - 10 FOR E9001 f 10 FOR E1900 Lions. All you need is a soldering iron, solder, a 10 FOR $7 1 00 100 FOR $80.00 100 FOR FOR. PRODUCTS AND MAIL ENTIRE AD TO $180 00s Ipower supply, and a standard RS232 terminal TO ORDER BY MAIL. CHECK BOXES DESIRED (Helm cs has 2 low -cost ones to choose from;. Explorer 88-PC Starter Kit...S3$9.95 I NETRONICS R&D LTD. E EtT IcS co + 10.00 pái i I O (wired á tested, add $100.00) 333 Litchfield Rd., New Milford, CT 06776 DExtra $2-pin connectors at $4.25 ea. I+ 1.00 pái. O Amount enclosed OR Charge my D VISA O MASTERCARD 905 S. VERMONT P.O. SOX 20406 LOS ANGELES, CA 90006 Use your own terminal with the EXPLORER 88-PC Acct. No. __ Exp. Date QUANTITIES LIMITED FOREIGN ORDERS Ior, if you plan to expand it to be fully IBM corm Signature MINIMUM ORDER $10.00 INCLUDE SUFFICIENT patible, we offer our IBM compatible keyboard PRINT NAME USA'. 9210 SHIPPING SHIPPING and an IBM compatible color graphics board NO CO.D! CALIF. RES. ADD 8', °.° Lon1y available wired and tested). Address City State __ Zip CIRCLE NO. 3 ON FREE INFORMATION CARD _1

www.americanradiohistory.comAmericanRadioHistory.Com 641(200 $595 G281( $41 4164 NSMIC T2O1 200 NS IC 5 r- STATIC RAMS r z-8o 8000 6800 r 74LS00 8035 5.95 2101 256 x 4 (450ns) 1.95 2.5 Mhz 68000 59.95 74LS00 .24 7415173 .69 8039 6.95 741.501 .55 5101 256 x 4 (450ns) (cmos) 3.95 Z80-CPU 3.95 6800 3.95 .25 7415174 INS -8060 17.95 6802 7.95 741,502 .25 74L5175 .55 2102-1 1024 x 1 (450ns) .89 Z80-CTC 4.49 INS -8073 24.95 6808 13.90 741503 .25 7415181 2.15 2102L-4 1024 x 1 (45ons)(LP) .99 Z80-DART 10.95 8080 3.95 6809E 19.95 741504 .24 7415189 8.95 2102L-2 1024 x 1 (250ns) (LP) 1.49 Z80-DMA 14.95 8085 5.95 2111 256 x 4 (150ns) 2.49 Z80-P10 4.49 6809 11.95 741505 .25 7415190 .89 8085A -2 11.95 2112 256 x 4 (450ns) 2.99 Z80-S10/0 16.95 6810 2.95 741508 .28 7415191 .89 8086 29.95 2114 1024 x 4 (450ns) 8/9.95 Z80-SIO/1 16.95 6820 4.35 741509 .29 7415192 .79 8087 CALL 2114L-4 1024 x 4 (450ns)(LP) 8/12.95 Z80-S10/2 16.95 6821 3.25 741510 .25 7415193 .79 8088 39.95 2114L-3 1024 x 4 (300ns) (LP) 8/13.45 Z80-SIO/9 16.95 6828 14.95 741511 .35 7415194 .69 8089 89.95 6840 12.95 741512 .35 7415195 .69 2114L-2 1024 s 4 (200ns) (LP) 8/13.95 4.0 Mhz 8155 6.95 6843 34.95 741513 .45 7415196 .79 2147 4096 s 1 (55ns) 4.95 Z80A-CPU 4.95 8155 -2 7.95 6844 25.95 741514 .59 741.5197 .79 TMS4044-4 4096 x 1 (450ns) 3.49 Z80A-CTC 4.95 8156 6.95 6845 14.95 741515 .35 7415221 .89 TMS4044-3 4096 x 1 (300ns) 3.99 Z80A-DART 11.95 8185 29.95 6847 11.95 741520 .25 7415240 .95 TMS4044-2 4096 x 1 (200ns) 4.49 280A-DMA 16.95 8185 -2 39.95 .99 MK4118 1024 x 8 (250ns) 9.95 6850 3.25 74LS2: .29 7415241 Z80A-PIO 4.95 8741 39.95 6852 TMM2018-200 2048 x 8 (200ns) 4.15 5.75 74LS22 .25 74LS242 .99 Z80A-S10/0 16.95 8748 24.95 TMM2016-150 2048 x 8 (150ns) 4.95 6860 9.95 74LS26 .29 74LS243 .99 Z80A-S10/1 16.95 24.95 .99 TMM2016-100 2048 x 8 (100ns) 6.15 `8755 6862 11.95 741527 .29 74LS244 Z80A-SI0/2 16.95 1.49 HM6116-4 2048 x 8 (200ns) (cmos) 4.75 6875 6.95 741528 .35 7415245 Z80A-SI0/9 16.95 6880 2.25 741530 .25 7415247 .75 HM6116-3 2048 x 8 (150ns) (cmos) 4.95 r 1 HM6118-2 2048 x 8 (120ns) (cmos) 8.95 6.0 Mhz 6883 22.95 741532 .29 7415248 .99 8200 68047 .55 .99 HM6116LP-1 2048 x 8 (200ns) (cmos)(LP) 5.95 Z808-CPU 11.95 24.95 741533 7415249 8202 24.95 68488 19.95 741537 .35 7415251 .59 HM6116LP-3 2048 x 8 (150ns) (cmos)(LP) 6.95 Z80B-CTC 13.95 8203 39.95 = .35 7415253 .59 HM6116LP-2 2048 x 8 (120ns) (cmos)(LP) 10.95 Z80B-P10 13.95 6800 1MHZ 741538 8205 3.50 Z-8132 4096 x 8 (300ns) (Os1at) 34.95 2808-DART 19.95 68800 10.95 741540 .25 7415257 .59 1.80 8212 68802 22.25 741542 .49 7415258 .59 LP = Low Power Octet = Quasi-Static 8214 3.85 ZILOG 681309E 29.95 741.547 .75 7415259 2.75 1.75 Z6132 34.95 8216 68809 29.95 74LS48 .75 7415260 .59 8224 2.25 `8671 39.95A 68810 6.95 74LS49 .75 7415266 .55 8226 1.80 68B21 6.95 741551 .25 7415273 1.49 3.49 r DYNAMIC RAMS 8228 68B45 19.95 741554 .29 7415275 3.35 rCRYSTALS, 8231 can 68B50 5.95 741555 .29 7415279 .49 TMS4027 4096 x 1 (250ns) 1.99 8237 19.95 741563 1.25 7415280 1.98 32.768 khz 1.95 68800 - 2 MHZ UPD411 4096 x 1 (300ns) 3.00 8237 -5 21.95 74LS73 .39 7415283 .69 1.0 mhz 4.95 MM5280 4096 x 1 (300ns) 3.00 8238 4.49 74LS74 .35 1.8432 4.95 7415290 .89 MK4108 8192 x 1 (200ns) 1.95 8243 4.45 741575 .39 74LS293 2.0 3.95 .89 MM5298 8192 x 1 (250ns) 1.85 8250 10.95 741576 .39 7415295 .99 3.95 r 6500 4116-300 16384 x 1 (300ns) 8/11.75 2.097152 8251 4.49 1 MHZ 741578 .49 7415298 .89 4116-250 16384 x 1 (250ns) 8/11.95 2.4576 3.95 8253 6.95 6502 4.95 741_583 .60 7415299 1.75 4116-200 16384 x 1 (200ns) 8/12.95 3.2768 3.95 8253 -5 7.95 6504 6.95 741585 .69 74LS323 3.50 4116-150 16384 z 1 (150ns) 8/14.95 3.579535 3.95 8255 4.49 6505 8.95 741586 .39 7415324 1.75 4116-120 18384x 1 (120ns) 8/29.95 4.0 3.95 8255 -5 5.25 6507 9.95 741590 .55 7415352 1.29 2118 16384 x 1 (15Ons) (5v) 4.95 5.0 3.95 8257 7.95 6520 4.35 741591 .89 7415353 1.29 4164-200 65536 x 1 (200ns)(5v) 5.95 5.0688 3.95 8257 -5 8.95 6522 7.95 741592 .55 74LS363 1.35 4184-150 1 5.185 3.95 65536 x (150ns)(5v) 6.95 8259 6.90 741593 .55 1.95 5.7143 3.95 6532 9.95 7415364 = 8259 -5 7.50 741595 .75 7415365 5V single 5 volt supply 6.0 3.95 6545 22.50 .49 8271 39.95 74LS96 6.144 3.95 6551 11.85 .89 74LS366 .49 8272 39.95 7415107 .39 6.5536 3.95 2 MHZ 7415367 .45 8275 29.95 741_5109 .39 8.0 3.95 6502A 6.95 7415368 .45 8279 8.95 7415112 EPROMS 10.0 3.95 6522A 9.95 .39 7415373 .99 8279 -5 10.00 7415113 .39 10.738635 3.95 6532A 11.95 7415374 .99 1702 256 x 8 (1us) 4.50 8282 6.50 7415114 .39 14.31818 3.95 6545A 27.95 7415377 1.39 2708 1024 x 8 (450ns) 3.95 8283 6.50 7415122 45 741.5378 1.18 15.0 3.95 6551A 11.95 2758 1024 x 8 (450ns) (5v) 5.95 8284 5.50 7415123 16.0 3.95 3 MHZ .79 7415379 1.35 2716 2048 x 8 (450ns)(5v) 3.95 8286 6.50 7415124 J 2.90 7415385 1.90 17.430 3.95 e 502 14.95 2716-1 2048 x 8 (350ns)(5v) 5.95 8287 6.50 7415125 .49 18.0 3.95 7415386 .45 TMS2516 2048 x 8 (450ns) (5v) 5.50 8288 25.00 7415126 18.432 3.95 .49 7415390 1.19 TMS2716 2048 x 8 (450ns) 7.95 ,8289 49.955 7415132 .59 7415393 1.19 20.0 3.95 r UARTS 1 TMS2532 4096 x 8 (450ns) (5v) 5.95 7415133 .59 1.19 22.1184 3.95 AY3-1014 6.95 74L5395 2732 4096 x 8 (450ns) (5v) 4.95 7415136 .39 `32.0 3.954 AY5-1013 3.95 7415399 1.49 2732-250 4096 z 8 (250ns)(5v) 8.95 r DISC AY3-1015 6.95 7415137 .99 74LS424 2.95 2732-200 4096 x 8 (200ns)(5v) 11.95 CONTROLLERS PT1472 9.95 74LS138 .55 7415447 .37 8192 x 8 2764 (450ns) (5v) 9.95 r 1771 16.95 TR1602 3.95 7415139 .55 7415490 1.95 2764-250 8192 x 8 CRT (250ns)(5v) 14.95 1791 24.95 2350 9.95 7415145 1.20 7415624 3.99 2764-200 8192 x 8 (200ns)(5v) 24.95 CONTROLLERS 1793 26.95 2651 8.95 7415147 2.49 7415640 2.20 6845 14.95 TMS2564 8192 x 8 (450ns) (5v) 17.95 1795 49.95 TMS6011 5.95 7415148 1.35 7415645 2.20 MC68764 x 8 (450ns) 68B45 19.95 8192 (5v)(24 pin) 39.95 1797 49.95 IM6402 7.95 7415151 .55 7415668 1.69 HD46505SP 15.95 7415153 .55 7415669 5v = Single 5 Volt Supply 2791 54.95 IM6403 8.95 1.89 6847 11.95 2793 54.95 INS8250 10.95 7415154 1.90 7415670 1.49 MC1372 6.95 2795 59.95 7415155 .69 7415674 9.65 68047 24.95 GENERATORS 2797 59.95 7415156 .69 7415682 3.20 8275 29.95 BIT-RATE 7415157 .65 7415683 3.20 6843 34.95 MC14411 11.95 EPROM ERASERS 7220 99.95 7415158 .59 741.5684 3.20 8272 39.95 11.95 Capacity Intensity CRT5027 39.95 BR1941 7415160 .69 7415685 3.20 UPD765 39.95 12.95 Timer Chip (uW /Cm2) CRT5037 49.95 4702 74LS161 .65 7415688 2.40 1691 17.95 16.95 TMS9918A 39.95 COM5016 7415162 .69 7415689 3.20 PE -14 6 5,200 83.00 0143 18.955 10.95 `DP8350 49.95 COM8116 7415163 .65 7415783 24.95 PE -14T X 6 119.00 10.95 5,200 M M5307 7415164 .69 811595 1.49 PE -24T X 9 6,700 175.00 CONNECTORS" FUNCTION 7415165 .95 811596 1.49 PL -265T X 20 6,700 255.00 KEYBOARD RS232 MALE 2.50 MC4024 3.95 7415166 1.95 811597 1.49 7415168 1.75 811598 1.49 PR -125T X 16 15,000 349.00 CHIPS RS232 FEMALE 3.25 LM566 1.49 AY5 -2376 11.95 RS232 HOOD 1.25 XR2206 3.75 7415169 1.75 25152521 2.80 -320 X 32 15,000 L8038 3.9_54d `7415170 1.49 25152569 4.25, 1-PR 595.005 LAYS-3600 11.95A S -100 ST 3.91A VISIT OUR RETAIL STORE HOURS: M -W -F, 9 -5 T -Th., 9 -9 Sat. 11 -3 PLEASE USE YOUR CUSTOMER NUMBER WHEN ORDERING JDR Microdevices TERMS' For shipping include S2 1or UPS Ground or $3 for UPS Blue Label Alr. Items over 5 pounds require additional shipping charges. 1224 S. Bascom Ave. San Jose, CA 95128 Foreign orders, include sufficient amount for shipping. There is a $13 minimum order. Bay Area and Los Angeles Counties add 6b2' -o Sales (408) 995 -5430 Telex 171 -110 Tax. Other California residents add 6 °, Sales Tax. We reserve the 0 right to substitute manufacturer. Not responsible for typographical errors. Prices are subject to change without notice. We will match or beat any competitors price provided it is not below our cost. 1983 JDR MICRODEVICES. INC.

www.americanradiohistory.comAmericanRadioHistory.Com 2114 .,0N= 8I$995 2114 .s O/$1O°s r 7400 LINEAR RCA CMOS r400 .19 74132 .45 LM301 .34 LM340 (see 7800) LM566 1.49 1M1800 2.37 CA 3023 2.75 CA 3082 1.65 4000 .29 4527 1.95 r401 .19 74136 .50 LM301H .79 LM348 .99 LM567 .89 LM1812 8.25 CA 3039 1.29 CA 3083 1.55 4001 .25 4528 1.19 r402 .19 74141 .65 LM307 .45 LM350K 4.95 NE570 3.95 LM1830 3.50 CA 3046 1.25 CA 3086 .80 4002 .25 4531 .95 7403 .19 74142 2.95 LM308 .69 LM3507 4.60 NE571 2.95 LM1871 5.49 CA 3059 2.90 CA 3089 2.99 4006 .89 4532 1.95 7404 .19 74143 2.95 LM308H 1.15 LM358 .69 NE592 2.75 LM1872 5.49 CA 3060 2.90 CA 3096 3.49 4007 .29 4538 1.95 7405 .25 74145 .60 LM309H 1.95 LM359 1.79 LM709 .59 LM1877 3.25 CA 3065 1.75 CA 3130 1.30 4008 .95 4539 1.95 74Q6 .29 74147 1.75 LM309K 1.25 LM376 3.75 LM710 .75 LM1889 1.95 CA 3080 1.10 CA 3140 1.15 4009 .39 4541 2.64 7407 .29 74148 1.20 LM310 1.75 LM377 1.95 LM711 .79 LM1896 1.75 CA 3081 1.65 CA 3146 1.85 4010 .45 4543 1.19 7408 .24 74150 1.35 LM311 .64 LM378 2.50 LM723 .49 ULN2003 2.49 CA 3160 1.19 4011 .25 4553 5.79 7409 .19 74151 .55 LM311H .89 LM379 4.50 LM723H .55 LM2877 2.05 4012 .25 4555 .95 7410 .19 74152 .65 LM312H 1.75 LM380 .89 LM733 .98 LM2878 2.25 4013 .38 4556 .95 7411 .25 74153 .55 LM317K 3.95 LM380N-8 1.10 LM741 .35 LM2900 .85 TI 4010 .79 4581 1.95 7412 .30 74154 1.25 LM317T 1.19 LM381 1.60 LM741N-14 .35 LM2901 1.00 TL494 4.20 75365 1.95 4015 .39 4582 1.95 7413 .35 74155 .75 LM318 1.49 LM382 1.60 LM741H .40 LM3900 .59 TL496 1.65 75450 .59 4016 .39 4584 .75 7414 .49 74156 .65 LM318H 1.59 LM383 1.95 LM747 .69 LM3905 1.25 TL497 3.25 75451 .39 4017 .69 4585 .75 7416 .25 74157 .55 LM319H 1.90 LM384 1.95 LM748 .59 LM3909 .98 75107 1.49 75452 .39 4018 .79 4702 12.95 7417 .25 74159 1.65 LM319 1.25 LM386 .89 LM1014 1.19 LM3911 2.25 75110 1.95 75453 .39 4019 .39 74C00 .35 7420 .19 74160 .85 LM320 (see 7900) LM387 1.40 LM1303 1.95 LM3914 3.95 75150 1.95 75454 .39 4020 .75 74CO2 .35 7421 .35 74161 .69 LM322 1.65 LM389 1.35 LM1310 1.49 LM3915 3.95 75154 1.95 75491 .79 4021 .79 74C04 .35 7422 .35 74162 .85 LM323K 4.95 LM390 1.95 MC1330 1.69 LM3916 3.95 75188 1.25 75492 .79 4022 .79 74C08 .35 7423 .29 74163 .69 LM324 .59 LM392 .69 MC1349 1.89 MC4024 3.95 75189 1.25 75493 .89 4023 .29 74C10 .35 7425 .29 74164 .85 LM329 .65 LM394H 4.60 MC1350 1.19 MC4044 4.50 75494 .89 4024 .65 74C14 .59 7426 .29 74165 .85 LM331 3.95 LM399H 5.00 MC1358 1.69 RC4136 1.25 4025 .29 74C20 .35 7427 .29 74166 1.00 LM334 1.19 NE531 2.95 MC1372 6.95 RC4151 3.95 4026 1.65 74C30 .35 7428 .45 74167 2.95 LM335 1.40 NE555 .34 LM1414 1.59 LM4250 1.75 BI IFET 4027 .45 74C32 .39 7430 .19 74170 1.65 LM336 1.75 NE556 .65 LM1458 .59 LM4500 3.25 TL071 .79 TL084 2.19 4028 .69 74C42 1.29 7432 .29 74172 5.95 LM337K 3.95 NE558 1.50 LM1488 .69 RC4558 .69 TL072 1.19 LF347 2.19 4029 .79 74C48 1.99 7433 .45 74173 .75 LM337T 1.95 NE561 24.95 LM1489 .69 LM13080 1.29 TL074 2.19 LF351 .60: 4030 .39 74C73 .65 7437 .29 74174 .89 LM338K 6.95 NE564 2.95 LM1496 .85 LM13600 1.49 TL081 .79 LF353 1.00 4034 1.95 74C74 .65 7438 .29 74175 .89 LM339 .99 LM565 .99 LM1558H 3.10 LM13700 1.49 TL082 1.19 LF355 1.10 4035 .85 74C76 .80 7440 .19 74176 .89 TL083 1.19 LF356 1.10 4040 .75 74C83 1.95 1.40 7442 .49 74177 .75 H_ TO -5 CAN T - TO -220 K TO-3 LF357 4041 .75 74C85 1.95 7443 .65 74178 1.15 4042 .69 74C86 .39 7444 .69 74179 1.75 4043 .85 74C89 4.50 7445 .69 74180 .75 rIC 4044 .79 74C90 1.19 7446 .69 74181 2.25 74S00 SOCKETS" r- VOLTAGE 4046 .85 74C93 1.75 1 -99 100 7447 .69 74182 .75 74S00 .32 74S163 1.95 4047 .95 74C95 .99 8 pin ST .13 .11 7448 .69 74184 2.00 74S02 .35 745168 3.95 REGULATORS 4049 .35 74C107 .89 14 pin ST .15 .12 7450 .19 74185 2.00 74S03 .35 745169 3.95 7805T .75 7905T .85 4050 .35 74C150 '5.75 16 pin ST .17 .08 7451 .23 74190 1.15 74SO4 .35 74S174 .95 7808T .75 7908T .85 4051 .79 74C151 2.25 18 pin ST .20 .18 7453 74191 1.15 74S05 .35 745175 .95 7812T .75 7912T .85 4053 .79 74C154 3.25 .23 20 pin ST .29 .27 7454 .23 74192 .79 74S08 .35 74S181 3.95 781ST .75 791ST .85 4060 .89 74C157 1.75 22 pin ST .30 .27 7460 .23 74193 .79 74509 .40 745182 2.95 7824T .75 79241 .85 4066 .39 74C160 1.19 24 pin ST .30 .27 7470 .35 74194 .85 74S10 .35 745188 1.95 4068 .39 74C161 1.19 28 pin ST .40 .32 7805K 1.39 7905K 1.49 7472 ' .29 74195 .85 74S11 .35 74S189 6.95 4069 .29 74C162 1.19 40 pin ST .49 .39 7812K 1.39 7912K 1.49 .34 74196 .79 74515 .35 745194 1.49 4070 .35 74C163 1.19 7473 64 pin ST 4.25 call 7815K 1.39 7915K 1.49 7474 .33 74197 .75 74520 .35 745195 1.49 1.39 1.49 4071 .29 74C164 1.39 ST = SOLDERTAIL 7824K 7924K 7475 .45 74198 1.35 74522 .35 74S196 1.49 4072 .29 74C165 2.00 8 pin WW .59 .49 7476 .35 74199 1.35 74S30 .35 745197 1.49 78L05 .69 79L05 .79 4073 .29 74C173 .79 14 pin WW .69 .52 7480 .59 74221 1.35 74S32 .40 745201 6.95 78L12 .69 79L12 .79 4075 .29 74C174 119 16 pin WW .49 .49 7481 1.10 74246 1.35 74S37 .88 745225 7.95 78L15 .69 79L15 .79 4076 .79 74C175 1.19 18 pin WW .99 .90 74247 1.25 74538 .85 74S240 2.20 4078 .29 74C192 1.49 7482 .95 20 pin WW 1.09 .98 78H05K 9.95 LM323K 4.95 7483 .50 74248 1.85 74540 .35 745241 2.20 4081 .29 74C193 1.49 22 pin WW 1.39 1.28 78H12K 9.95 UA78S40 1.95 7485 .59 74249 1.95 74S51 .35 74S244 2.20 = 4082 .29 74C195 1.39 24 pin WW 1.49 1.35 T -= TO-220 K TO-3 7486 .35 74251 .75 74S64 .40 74S251 .95 4085 .95 74C200 5.75 28 pin WW 1.69 1.49 L - TO-92 J 7489 2.15 74259 2.25 74S65 .40 745253 .95 L. 4086 .95 74C221 1.75 40 pin WW 1.99 1.80 7490 .35 74265 1.35 74S74 .50 74S257 .95 4093 .49 74C373 2.45 WW = WIREWRAP 7491 .40 74273 1.95 74S85 1.99 745258 .95 4098 2.49 74C374 2.45 16 pin ZIF 6.75 call 7492 .50 74276 1.25 74586 .50 745260 .79 r DIP r INTERFACE 4099 1.95 74C901 .39 24 pin ZIF 9.95 call 7493 .35 74279 .75 74S112 .50 745274 19.95 8T26 1.59 14409 12.95 74C902 .85 28 pin ZIF 10.95 call SWITCHES 7494 .65 74283 2.00 74S113 .50 745275 19.95 8728 1.89 14410 12.95 74C903 .85 ZIF - TEXTOOL 74284 3.75 745114 .55 745280 1.95 8795 .89 14411 11.95 74C905 10.95 7495 .55 (Zero Insertion Force) 4 POSITION .85 7496 .70 74285 3.75 745124 2.75 74S287 1.90 8796 .89 14412 12.95 74C906 .95 7497 2.75 74290 .95 74S132 1.24 74S288 1.90 5 POSITION .90 8T'97 .89 14419 7.95 74C907 1.00 74100 1.75 74293 .75 745133 .45 745289. 6.89 8T'98 .89 14433 4.18 74C908 2.00 74107 .30 74298 .85 74S134 .50 745301 6.95 LED LAMPS 6 POSITION .90 DM8131 2.95 4502 .95 74C909 2.75 1 -99 100 -up 74109 .45 74351 2.25 745135 .89 745373 2.45 DP8304 2.29 4503 .65 74C910 9.95 Red .10 .09 7 POSITION .95 74110 .45 74365 .65 745138 .85 745374 2.45 DS8835 1.99 4508 1.95 74C91 t 8.95 .18 .15 74111 .55 74366 .65 745139 .85 745381 7.95 Green DS8836 .99 4510 .85 74C912 8.95 Yellow .18 .15 `8 POSITION .95A 74116 1.55 74367 .65 74S140 .55 745387 1.95 MISC. 4511 .85 74C914 1.95 1.20 74368 .65 745151 .95 74S412 2.98 4512 .85 74C915 1.19 74120 ULN2003 2.49 74376 2.20 74S153 .95 74S471 4.95 4514 1.25 74C918 2.75 74121 .29 3242 7.95 74390 1.75 745157 .95 74S472 4.95 4515 1.79 74C920 17.95 74122 .45 LED DISPLAYS , 3341 4.95 1.35 745158 .95 745474 4.95 HP 5082-7760 .6" CC 1.29 4516 1.55 74C921 15.95 74123 .49 74393 MC3470 4.95 74425 3.15 74S161 1.95 745482 15.25 MAN 72 4518 .89 74C922 4.49 74125 .45 .3" CA .99 MC3480 9.00 745162 1.95 745570 4519 .39 74C923 4.95 74126 .45 74426 .85 2.95 MAN 74 .3" CC .99 11C90 13.95 74S571 2.95 4520 .79 74C925 5.95 74128 .55 74490 2.55 FND-357 (359) .375" CC 1.25 7.95 951190 4522 1.25 74C926 7.95 FND-500 (503) .5" CC 1.49 2513-001 UP 9.95 4526 1.25 74C928 7.95 LFND-507 (510) .5" CA 1.49A r `2513-002 LOW 9.99A 74C929 19.95 CLOCK INTERSIL 7 9000 -9 L CIRCUITS ICL7103 9.50 9316 1.00 MM5314 4.95 ICL7106 9.95 9334 2.50 EXAR DATA ACQUISITION r- SOUND CHIPS 3.95 MM5369 3.95 ICL7107 12.95 9368 rXR 2206 3.75 ADC0800 15.55 DAC0808 2.95 76477 3.95 9.95 M M 5375 4.95 1CL7660 2.95 9401 XR 2207 3.75 ADC0804 3.49 DAC1020 8.25 76489 8.95 MM58167 8.95 ICL8038 3.95 9601 .75 XR 2208 3.75 ADC0809 4.49 DAC1022 5.95 AY3-8910 12.95 1.50 MM58174 11.95 ICM7207A 5.59 9602 XR 2211 5.25 ADC0817 9.95 MC1408L6 1.95 AY3-8912 12.95 MSM5832 6.95 `CM7208 15.95 126502 1.9 LXR 2240 3.254 `DAC0800 4.95 MC1408L8 2.95 1MC3340 1.49 ORDER TOLL FREE 800 -538 -5000 800- 662 -8279 ALL MERCHANDISE - 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CIRCLE NO. 22 ON FREE INFORMATION CARD

www.americanradiohistory.comAmericanRadioHistory.Com DIDI-KEY I Mì. 718081.66]4 C O R P O R A T O N 800-346-5144In Mn.. Ak., Call CHEMICALS ARIES MOLEX NATIONAL SEMICONDUCTOR PANASONIC QUALITY recognized manufacturers. - Name brand products from nationally DIAMOND TOOL.PLE S Y M C E BISHOP N. AAVI CHEMWIK GRAPHICS. AS INSTRUMENTS ITT AP E DIP mast,' charge MOLEX AAVID E F. JI order processing and inventory control VISA ARIESQ PLESSEY SERVICE - Computerized IND TOOL UNGAR GC CHEMICALS ARIES - OK MACHINE UNGAR GC CHEMICALS A S PANASONIC SAVINGS Volume Discounts OEM Quantity Pricing TOIL Free BOO Number CHEMICALS ARIES PLESSEV MOLEX E. NATIONAL SEMICONDUCTOR - KIY OIG,. KEY DIGI KEY KEY KEY KEY - 0101 KEY OIM KY 19 - DIGI KEY - D90: !PI - DICI KEY - DIGI KEY DIGI OIDI - - Th. R9K Illra-AFl rli """T mnkr.nN Price 1lfffr I0I77 I._010117Ir.- OIGIKE9 0101 KEY - 0,0 . KEY - DIG: KEY - DIGISI DE! DIG, Kt, Mr KEY 0107 KEY -. 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the -Key may be combined for o volume dnc0um. Items that are not discountable are identified by VOLUME DISCOUNT The Der-Key volume discount and Service charges are simple to apply. Mot items sold by Di5i SERVICE CHARGES the appropriate discount. To this subtotal, odd the col dMountable items. Then odd 5 0.00 -5 99.99 NET suffix-ND following the part number. After writing your order, total all of the discountable items owl apply S 0.00-5 9.99 Add 52.00 a0LOmpoTes Orrin. S 100.00. 5249.99.... Less 10. the Willi, charge. We pay oil shipping old insurance to addresses in the U.S.A.. Canada and Mexico when payment B 10.00 -525.00 Add 50.75 SA711I 5 250.004499.99 Less 15.. mid sow erder 151 DOGI-OIT. NIIEYw y 32 $sIh. TAM BIN Ms. Ala 5 25.00.549.99 Add 50.50 .... WORN OSOESIRG UV NONE, CALL, 1.010.4470 -3144 (li-, M., Ni., old 218.681404)h er S0.25 Any pelts or products purchased from Dlgi-Key that prove Io be defective will be 99 -you may pay by ChEk move order, Master 00079K. VISA re C,0.0. DIGS-KEY GUARANTEE: 5730.0 á ú Ndd 0.25 51000.00 6 Up 99 Less 25. replaced or refunded If reNned within 90 days from receipt with o copy of your invoke

www.americanradiohistory.comAmericanRadioHistory.Com DIGI-KEY C O R P O R A T I O N Cal1 800-346-51.44In Mn, Ak. Hi. 711-611-6674 NATIONAL SEMICONDUCTOR PANASONIC QUALITY - Name brand products from nationally recognized manufacturers. CHEMICALS ARIES Passer MOLEX E. AAVlO CHEMWIK OISHOP GRAPHICS , N. MACHINE DIAMOND TOOL. UNGAR GC. CH VISA ARIES PLESSEY MOLEX nAAVID E. P. Jr SERVICE Computerized order processing and inventory control AS INSTRUMENTS ITT AT PRODUCTS Dip OK - /ND CHEMICALS ARIES NATIIONAL SEMICONDUCTOR PANASONIC SA VINOS - Volume Discounts OEM Quantity Prici,, Toll Free B00 Number EMIICCALS AR ES PLESSEYEY ar.I DI FRET O101 0101 Kr. -OIOr REV - Olaf REY -D101- NET -D101eE 0D 1 0I01 R1 CIGLREr 01GI.KE - DIObK r- DIOrKFr - DIGS k[r - DIO6KEr - 0101 RE 101 K 1 NI, O DP. 4 0191 RE - 9161 RF. 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The DIgI -Key volume discount and handling Charges ore simple to apply Most it ems sold by Digi -Key may be combined for o volume dí51000 Items Mot ore not discountable are identified by t HANDLING CHARGES VOLUME DISCOUNT suffolND following the port number. After wr Mg your order total all of the discountable items and apply the appropriate discount. To Iles subtotal, add the non.discountable items. Then d S 0.005 9.99 Add 67.00 S 0.00 -5 99.99. 98[1 Me Kindling charge. We pov all shipping and insurance to oddresses in the d.5. A. , Canada and Mexico when check or money order accompanies odor. If 10.00.525.00 Add 50.75 5 100.00 -5249.99. Lo.. 10'. MINIM NOISING IT MOM, I -SO CAlll -346 -SIDO I. AL, Ni., eel 2I1.9814474) Sy 'mil semi ,ex Nor N: DIGI-DIO, NIEIIeme 32 SeeA, tMfel Myer fade, MN 56751 5 23.00.549.99 Add 50.50 S 250.00- 5499.99.... Less 15'. You boy pay by check, money order. MoSter barge. VISA o C.O.D. DIGI -KEY GUARANTEE: Any ports or products purchased from Dpi -Key tilt prove to be defective will Ss S 50.00- 599.99 Add 50.25 S 500.00- 5999.99.... Less 20'. r1010151 N refunded if returned within 90 days from receipt with a copy of your invoice. FIibes su LOCI 10 change wllhaal 1111150. S 100.00 6 Up No Charge 51000.00 C. Up Less 25 Circle No. 14 on Free Information Card www.americanradiohistory.comAmericanRadioHistory.Com SUMMER PROJECTS START WITH SHACK® PARTS No Minimum Order! No Mail -Order Delays! See Before You Buy! Ceramic TV -Sound Filters Deluxe LCD Autoranging Over-Voltage Sensor IC NEW! Multimeter ( NEW! 159 C Low As NEW Protects Sensitive \VI /ri LOW Transformers Electronic Circuits Replace Costly PRICE! Pre -Tuned, No Tweaking Needed 8 -Pin Dip With Data MC3423. Monitors the supply rail and triggers an SFE4.5MB. Perfect for video projects! Will also external LED or a crowbar SCR in the event of line 4.5 MHz sound in many solid - replace transformer transients or loss of regulation. Operates with sup- circuits. 3 dB bandwidth: 105 kHz, typical. state 6995 ply voltages from 4.5 to 50 volts DC. 272 -1304 69C Was $89.95 in 276 -1717 1 59 CDA4.5MD3 Discriminator. Ceramic differential 1983 Catalog peak detector. Works great with our FM detector IC #276-1759 272-1305 79C Super Handy "Beep" IC Continuity Timer Sale! 10 x 10cm Solar Cell Checker Ready -to -Use, NEW! 249 With Leads & 16 -Pin DIP With Data t Save $5 Manual ;i. pA2240 Programmable Timer Counter. Pro- Reg5. 1295 The DVM that thinks! You choose the function. it vides very accurate timing from microseconds to 17.9 selects range automatically -even if test leads days. Consists of a time -base oscillator, an eight - Harness "Free.' Power are reversed. Selectable continuity and range - bit counter, a control flip -flop and a voltage regula- That's Available change "beep" indicator. Makes highly accurate tor. Frequency of the time base is set by external tip low- resistance measurements. Low -battery and resistor and capacitor and can be synchronized or mss, Day! Every Sunny overrange indicators. Measures up 1000 volts modulated. A time -base output may be used to 2 Build a panel for charging batteries or powering DC. 500 volts AC, 200 milliamps (AC and DC). monitor frequency or provide pulse to other cir- projects. This quality cell, approximately 4" megs resistance. Accuracy: ± 1 digit cuitry. The eight outputs are TTL. DTL and CMOS , square, produces 0.42 VDC at 2 amps in full sun. 63/s x 3,/2x 1 /t1 With spare fuse, test leads and compatible. 5 to 15VDC operation, single supply. Wire several in series for more voltage manual. Requires two "AA" batteries. 16 -pin DIP with specs and data. 276 -128 Sale 12.95 22 -192 69.95 276 -1735 2 49 Rectangular LED Double Closed Micro 5VDC Micronta' Precision Circuit Jack Relay DC Panel Meters Pkg. of 2 159 3- Conductor NEW NEW Type LOW 199 LOW 7o Reg. PRICE! PRICES! C 96 For 'l.,' phone plug. Can 99C J be wired to disconnect Was $2.49 in 1983 Catalog 795 Orange. high brightness type. Can speakers automatically Shown actual size -ideal for Each be stacked vertically or horizon- when stereo headphones crowded boards. SPDT contacts: NEW! Were $8.95 I tal ly. 276 -074 Sale. 2/59e are plugged in 1A at 125VAC. 55 -ohm coil. 274 -1240 1.59 275 -240 1.99 in 1983 I Catalog Panel Tone -Dialing Encoder Manufacturer's Prime Jeweled D'Arsonval Movements Lettering 16 -Pin Accuracy ± 5 %, Full Scale With Data Microwave Devices w 259 Cut NEW! [B 199 Know "what's going on" in critical DC 40% 399 _7 circuits. All are 27 /4 x 2,h x 1'h," and Four sheets with rub - Pkg. of 2 require a 17 /r" round mounting hole. on letters, symbols, 0 to 50 Microamps. 270 -1751 .. 7.95 tk, numbers and calibra- Dependability 0 to 1 Milliamp. 270 -1752 7 95 ting marks At a Bargain Price! 299 0 to 15 Volts. 270 -1754. 7 95 270 -201 2.59 TCM5089. Accurate. stable dual n MRF -901. Low -noise NPN tran- tone output -meets industry stan- sistor for use up to 2 Gigahertz. 300 Layout Template Tantalum Capacitors dards without adjustment. Just add mW maximum dissipation. keyboard (a pushbutton switch ma- 276 -2044 2 99 y= Low As trix will do), resistor, colorburst crys- 01 H -P 5082 -2835. Low -noise Half 149 tal ( #272 -1310) and power source to Ideal for }?p po_p ]j 49C operate. Electronic input. too -usa- Schottky barrier diodes. UHF and microwave mixers. 1 pF Price z ÿg Each ble in an auto -dial modem. Powered ..rsnte 4416T from phone line or 9VDC. maximum capacitance. 276 -1124 Pkg. of 2/1.99 Durable, transparent stencil with 53 276 -1301 3 99 useful shapes. Really handy. 20% Tolerance 4,/2x 6 x 1/40': 276 -181 Sale 1.49 16 WVDC Minimum SPST Toggle Switch DC Motor Large Capacity in With LED Indicator Bargain Transformer, A Very Compact Size * NEW 6VAC . pF Cat. No. Each LOW 259 PRICE! 99` Save $1 0.1 272 -1432 .49 Was $2.99 in 0.47 272 -1433 .49 1983 Catalog Re99g. 199 1.0 272 -1434 .49 2. Rated 5 amps, 121/6 For models. robots, 272 -1435 .59 2.2 rillOnly. 3/4 X 3/4 X 1/2". etc. Long -life bear- Primary: 120VAC. Secondary 6.3VAC at 10 272 -1436 .69 7/16" mounting hole. ings. 1.5 to 6VDC. 450 mA maximum. 17/16 x 23/6 x 11/2" 22 272 -1437 .79 275 -680 2 59 273 -222 .. 4/99e Cut.33 %. 273 -1364 Sale 1.99

A DIVISION OF TANDY CORPORATION ftadue ¡hadi OVER 8700 LOCATIONS WORLDWIDE Prices apply at participating Radio Shack stores and dealers.

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HI -FI SPEAKER KITS and raw drivers from the world's fin- FOR SALE est manufacturers. For beginners and audiophiles. Free information. A &S SPEAKERS, Box 7462C, Denver, CO GOVERNMENT and industrial surplus receivers, trans- CABLE TV (303) 399 -8609. mitters, snooperscopes, electronic parts, Picture Cata- Buy Direct & Save 80207, log 25 cents. Meshna, Nahant, Mass. 01908. SATELLITE TV RECEIVER BREAKTHROUGH! Build your own commercial quality receiver now! Instruction man- kits. FREE FLYER. SUPER SPECIALS ELECTRONIC PARTS, semiconductors, uals. schematics, circuit boards! Send stamped enve- Large catalog $1.00 deposit. BIGELOW ELECTRONICS, lope: XANDI, Box 25647, Dept 22N, Tempe, AZ 85282. Bluffton. Ohio 45817. ® CHANNEL PCB 15C sq -in. FREE DRILLING. Quantity Discounts. In- BUILD AND SAVE. TV EARTH STATION. DETECTIVE CONVERTER 6452 Hazel Circle, Simi -Valley, CA i s29as ternational Enterprise. ELECTRONICS. Video Recorders, Color Cameras, ad- 93063. vanced Telephone Projects. BROADCAST Electronics. 50 Advanced Solid State design and cir. cuitry allows you to receive mid 6 MATV /CATV /VCR equipment, Antennas. electronic projects AIR WHOLESALE: page color catalog of unusual super band channels. Restores pro. Audio, Cables, Adapters. Original and Replacement Car- dramatization gramming Video Recorders. MAILED $3.00; with 3 hour audio cassette to tridges, Styli, Telephone Accessories, Radios. Cassette PO Drawer of our catalog $5.00. Don Britton Enterprises, 36 CHANNEL Recorders, Speakers, etc. Send letterhead for catalog, G, Waikiki, Hawaii 96815. REMOTE CONTROL 212- 897 -0509, D &WP, 66 -19 Booth, Rego Park, NY 11374. CABLE CONVERTER RECONDITIONED TEST EQUIPMENT $1.00 for catalog. s69" FREE CATALOG. Large selection of electronic kits and TEST EQUIPMENT, 2697 Nickel, San Pablo, CA WALTER'S -,JERROLD 400 parts. Chaney Electronics, Box 27038, Denver, Colorado 94806. (415) 724-0587. THE ULTIMATE CABLE TV 80227.(303)781 -5750. CONVERTER ELECTRONIC PARTS. Stamp for flyer, $1.00 deposit for 60 CHANNEL ELECTRONICS, 3029 N. Wilshire, INFRARED catalog. DAYTAPRO ..a111 _ AM. Arlington Hts., IL 60004. REMOTE CONTROL T ELECTRONIC CATALOG. Over 4,500 items. Parts, & com- s129ss _4 ll'B ponents. Everything needed by the hobbyist or techni- Send i5 for Complete Catalog & (United States Only), REMOVES VOLA 8T STEREO DISCS cian. $2.00 postage handling The Thompson Vocal Eliminator DIRECT SALES can actually remove most or refundable with first $15.00 order. T & M Electronics, 472 VIDEO virtually all of a solo vocalist from a standard stereo record and yet P.U. BOO 1326 East Main St., Patchogue, NY 11772. (516) 289 -2520. leave most of the background music untouched! Not an equalizer I We JEFFERSONVILLE. INDIANA 47130 can prove it works over the phone. Write or call for a 24 page brochure and demo record. PRINTED CIRCUIT BOARDS, your artwork. Quick deliv- CALL Write to: LT Sound, Dept. C E, P.O. Box 338. Stone Mountain, NC 1412.282.4766 ery. 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PAIA Electronics, Box J14359, Oklahoma ELECTRONICS WAREHOUSE CORP. SUCKING SOLDER MADE EASY. Finally, one -handed de- City, OK 73114. 1910 Coney Island Avenue Dept. CE -7 soldering with your gun. Superb results with surplus Brooklyn, N.Y. 11230 (212) 375-2700 vacuum pump. Tip assembly $14 postpaid. Complete in- SATELLITE TV structions, free brochure. Gerkman Engineering, Box 28251, Detroit, MI 48228. FANTASTIC 80 El CHANNELS FREE FLYER 99 cent kits. Parts. Bargains Galore! ALLKIT, 434 West 4th St., West Islip, New York 11795. SATELLITE TELEVISION: Receivers $300, Dishes $100.. New antenna construction plans plus big 8x 11 LNA's, Microwave equipment. Catalog $5.00. Satellite 14WV2W5 1% NO book loaded with aiming info, kits, LNAs and re- RESISTORS, %C.F., 36 ea.. Metalfilms. Systems, Box 184, Milpitas, CA 95035. ceivers at wholesale prices. Far better than cable MINIMUMS. Quantity Discounts. Write: JR INDUSTRIES, TV! Enjoy crystal clear reception. Send $9.95 to- 5834 -A Swancreek, Toledo, OH 43614. day. Add $2.00 for 1st class (air mail) or call our MICROWAVE ANTENNA SYSTEMS 24 hr. COD order line (305)862 -5068 Now. 34 Global TV Electronics. P.O. Box 219 -E. Maitland. FL 32751 IF YOU ARE READY TO BUY OR SELL Freq. 2.1 to 2.6 GHz db Gain GAMES OR SOFTWARE, YOU NEED... COMPLETE SYSTEMS las pictured! RF MODULATORS for SATELLITE TELEVISION, MICRO- Commercial 40' Rod Style $899`, kits. FREE Parabolic 20' Dish Style $79 95 COMPUTERS, CCTV. Also monitors, cameras, C1711F7u I erZ SMa7aPZr? VIDEO CATALOG. Phone (402) 987 -3771. Dealers Wel- TWO YEAR WARRANTY comed. ATV RESEARCH, 13 -P Broadway, Dakota City, NE Over 100 pages each month. Deal with individuals nation- PARTS AND LABOR 68731. wide. Low ad rate. only 12' a word. Subscription. $10 /year. CALL OR WRITE FOR KITS PARTS MC & VISA. Money back guarantee. 407 S. Washington, INDIVIDUAL COMPONENTS CABLE TV CONVERTERS & EQUIPMENT. Plans and P.O. Box F599, Titusville. FL 32780. 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C & D ELECTRONICS INC., P.O. Box 21, Jenison, MI Phillips -Tech 41Niti 49428. CABLE TV Electronics VISA FREE FLYER! IC's, resistors, capacitors, jacks, etc., plus P.O. BOK 34772 CONVERTERS & EQUIPMENT SSM music synthesizer /audio IC's, power amp modules, Phoenix. AZ 85067 analog delay IC's, computer books, and more. Also plans 16021265-8255 COO'S PGS Electronics, Route 25, for analog delay /chorus unit! We have the largest selection of Special Quantity Pricing Dealers Wanted Box 304 Terre Haute, IN 47802. JERROLD and OAK cable converters and equipment. Such as: Jerrold SB-3, Oak N12 61 channel remote SATELLITE RECEIVING SYSTEMS, COMMUNICATION and Jerrold AND ELECTRONIC SPECIALTIES computerized push- SATELLITE TV control converter with FULL features button TELEPHONES from $13.95. CORDLESS TELE- SYSTEMS COMPONENTS LNA's DRX3 -DIC -105. Plus others. PHONES 700' range from $99.95, satellite tvro systems, ANTENNAS RECEIVERS choose from 12 different manufacturers, from $1880.00, write: STAR SYSTEMS, P.O. Box 245, Ontonagon, MI WE CAN HELP VOUI CABLE TV KITS 49953. (906) 884 -4877. HIGH FRONTIER POLICE CODE UNSCRAMBLERS; lets you hear the coded Cable TV Kit (Jerrold gated pulse) 39.95. 2230 E. Indian School Rd., Phoenix, AZ 85016 messages of Police, Fire and Medical channels; plus other 954 -6008 scanner accessories; satisfaction guaranteed: DNE, Inc., (602) We also have a large selection of cable TV Rt. 7, Box 257A, Hot Springs, AR 71901, 501- 623 -6027. and kits including all parts, silk screen, PC Copy Military, Press, Weather, PRINTED CIRCUIT BOARDS and Electronic Compo- TELETYPE EQUIPMENT: board and complete instructions. Amateur, Commercial Transmissions. Catalog $1.00. nents. Gemini Projects, P.O. Box 35251, Chicago, IL 60635 WEATHER -MAP RECORDERS: Copy Satellite Photo- or 312/456 -4709. Send for informative catalogue $2.00 graphs, National -Local Weather Maps. Learn How! $1.00. TELEPHONES and ACCESSORIES. FCC registered. Send Atlantic Sales, 3730 Nautilus Ave., Brooklyn, NY 11224. $2.00 for 72 page catalog (refundable). UNIQUE COM- Phone: (212)372 -0349. J & W ELECTRONICS, INC. MUNICATIONS, INC., P.O. Box 5234, Mansfield, OH 44901. PRINTED CIRCUIT BOARDS. QUICK PROTOTYPES, TINKERTRON: Write for summer 1983 Electronics Cata- production, design, reflow solder. Send print or descrip- P.O. BOX 61 -K log. Includes Voltage and Current Variable Power supplies, tion for quote to: KIT CIRCUITS, Box 235, Clawson, MI Audio Amp Modules, Remote Wireless switches and Electronic Parts. LOWEST PRICES -SAVE UP TO 50% or 48017. CUMBERLAND, RI. 02864 MORE! Send 256 to: TinkerTron, Department C, P.O. Box CABLE TV SECRETS, the informative publication the ca- 53128, Lubbock, Texas 79453. ble companies are trying to ban. HBO, Movie Channel, BIG SAVINGS ON CONY TRANSMITTERS -Up to 30% ELECTRONICS BARGAIN CATALOG- Write: Opal East Showtime converters, etc. Send $8.95 to: CABLE FACTS, OFF( Send two stamps for catalog. S.E. Corp., Box 1132 - Co., Box 0 -38, 323 Franklin Bldg. S., Suite 804, Chicago, Box 711 -PE, Pataskala, Ohio 43062. PC, Yorba Linda, CA 92686. IL 60606.

www.americanradiohistory.comAmericanRadioHistory.Com APPLE, TRS -80. Stock market software. Free informa- COMPUTER PUBLICATIONS tion. Stock Market Computers, 235 Mesa Avenue, New- FREE Catalog of special function IC's and quality com- bury Park, CA 91320, (213) 884 -6900. ponents. Goldsmith Scientific, Box 318M, Commack, New TIMEX -SINCLAIR USERS: Join the group of newsletter York 11725. subscribers who receive free programs every month! TRANSIENT ANALYSIS and NETWORK THEOREMS, two Software discounts, Free program, issue and catalog. Z- new texts by Dr. Harry E. Stockman. Request Flyer. Ser- WEST, Box 2411, Vista, CA 92083. colab, Box 78B, Arlington, MA, 02174. TI -99/4A MOON TRIP animated graphic program on cas- SOFTWARE AUTHORS: Join the National Association of sette. Guide module through astroid belt. Then land on Freelance Programmera (NAFLP) and receive NAFLP's moon. Speech synthesizer and joyst capability. $12.00 Causes speed radar guns and devices to read out your choice of monthly SOFTWARE MARKET LETTER. Learn how and postpaid. JAG Software, P.O. Box 2225, Dept 10E, Ocean, either a percentage of your the speed when in automatic mode where to sell your software and get programming con- Your speed: 76 mph, auto mode set for 75%, speed New Jersey 07712. (example: tracts. For info, write: NAFLP, Box 813CE, Vienna, VA dispiayed - 57 mph), or the speed that you dal in when in manual of speed radar, or by manual 22180; 703-938-9191. mode. Transmits only in the presence DISCOUNT SOFTWARE- Available for Apple, TRS - override. Operates on both X and K bands. WARNING: The device described in this literature is rot legal for use against police radar, 80, IBM /PC and TI 99/4 personal computers. COMPUTER HARDWARE and is not FCC approved. dentist, CHADWELL'S MONTHLY SPECIAL -ZX81 16K Expan- For complete literature and plan package, send 8 1945 to: Professional applications for the doctor, sion cartridge, $40.95ÚS + $2.50p.h., VIC20 16K Expan- Inc. school administrator, teacher, contrac- Philips InstrumentDqigtt Co. attorney, sion cartridge, $69.96US + $2.50p.h., VIC20 32K 8135 S.W Nimbus. Building #11, Suite 0114 C 16K + Beaverton, Oregon 97005 tor and general office personnel. Catalog $1.00. Expansion cartridge, $99.95US + $3.50p.h., VIC20 +$2.50p.h., Write for MONTHLY SPECIAL OFFERS! Creative cartridge slot Expansion cartridge, $74.95US ZX81 High Resolution Graphics Expansion cartridge CLOSEOUT SPECIALS- Detector Circuits (for count- Discount Software, 256 S. Robertson Blvd., Suite $89.95ÚS + $3.50 p.h. Send $1.00 for catalogue: CHAD - ing, security systems, etc.) developed for fibreoptic WELL'S SOFTWARE, #230, 4144A -97 Street, Edmonton, sensing channels, with 5 VDC Power supply, with A/ 2156, Beverly Hills, CA 90211. -7 Alberta, Canada T6E 5Y6. US orders welcome. D conversion. Schematic supplied, $20.00. 3 -Digit Dec- COMPUTER PAPER -SAVE$$$; Lowest single carton imal Counter PC Boards -with readout and reset button - prices. Free samples. Bob's Charts, 405 East Third, Long AMATEUR RADIO requires 4- 5VDC- 71C's. Schematic supplied, $15.00. Beach, CA 90802. RADIO AMATEUR CALLBOOKS: 1983 Directories of Ra- Transformers -Triad 12.6 CT Volts -50/60 Hz F44X -2 AMP - dio Amateurs around the world. U.S. Callbook $23.00; 115v Primary -1 15/16 x 3 5/16 x 2, $5.00. Potentiome- ATARI, APPLE, IBM -PC: Extensive line educa- Foreign Callbook $22.00, shipping included. See your ters-VRN INT. -20K, Ten Turns, 3/4 W., $.25. Rectifier business. FREE BRO- Dealer or write for FREE catalog. RADIO AMATEUR Bridges -Motorola 312 case, 50 VRM, 45a, MDA 100, $1.00. tional, entertainment, CALLBOOK, Dept CE, 925 Sherwood Dr., Lake Bluff, IL TTL's 74LS32N -Ouad 2 -input OR gate $.35, 74LS123 -Dual CHURE. New Dimension Software, 39010 Baroque, Amps - 60044. One Shot $.90, 74LS90- Decade Counter 8.60. OP Mt. Clemens, Michigan 48044. LM324 Quad $1.05. LED's -FLV 100 $.10. Metal Oxide Var- VIDEOSCAN 1000 Slow Scan TV - HIGH RESOLUTION istors-MOV 150v -V150 LA 10A $.75. MINIMUM ORDER TI -99/4A PROGRAMMERS: Affordable Software! Cata- (amateur, phone line, monitoring, teleconferencing). $10.00. Mass. residents add 5% sales tax. Certified log, only $1. PROGRAMS SOFTWARE, 1435 Burnley CODE *STAR - DECODE Morse, RTTY, ASCII. LARGE check, M.O.- Freight prepaid. C.O.D.'s- Freight post- Square North, Columbus, Ohio 43229. LEDs or connect computer /printer. MORSE -A -KEYER - Ray paid. PROGRAMS 8 ANALYSIS INC., Dept JPC, 21 QUALITY COMPUTER SOFTWARE, VIC-20, Commodore CW Keyboard. TRI -VOLTAGE POWER SUPPLY. Kits /As- 272 198. Avenue, Burlington, MA 01803, (617) -7723, Ext. 64, Atari. Games, Home, Ham radio. Large list, SASE. Am- sembled. FREE brochures. MICROCRAFT CORPORA- ateur Accessories, Harvest Court, Flemington, New Jer- TION, Box 513 -PE, Thiensville, WI 53092. (414) 241 -8144. COMPUTER EQUIPMENT /PARTS sey 08822. (201)782-1551. TIMEX /SINCLAIR SAVE 90% Build Your own Minicomputer. Free Details. Di- name pro- FREE money saving bulletin on popular brand FREE SOFTWARE/HARDWARE CATALOG for your TS/ZX- gatek, 2723 West Butler Dr., Suite 20C, Phoenix, AZ 85021. grams for your small computer. Superior, Dept and books 81 16K: New programs. JPR SOFTWARE, Box 4155, Win- 45069. APPLE SERIAL CARD. Communicate with MODEM or ter- CE, 8030 Westchester Road, Westchester, OH ter Park, FL 32793. minal. Switch selectable serial printer protocol, $46.95 /kit SASEs FREE Timex /VIC- 20/T199-4A programs! /cata- KROPK STAR SEARCH, NOAH'S ARK, finest programs $61.95 /assm. Comprehensive manual, DB -25 connector, Diego, logs. Low prices! EZRAEZRA, Box 5222 -C, San available. Machine Language action, graphics. SASE 6 month warranty. CHECK or C.O.D. B &D ELECTRONICS, California 92105. Brown Cottage, 5486 Bright Hawk, Columbia, MD 21045. Box 3651, Lawrence, KS 66044. Lighthouse FREE VIC -20 Software -Hardware catalog. "MUST- HAVE "I Utility SOFTWARE. Cassettes-reload- WANT A PLEASANT SURPRISE? Call or write for quotes: 48183. Sales, Dept. A, P.O. Box 68, Trenton, MI machine language. SASE for information. SIRIUS Atari, Commodore, Timex, T.I., Corona (IBM work -alike), able /TS1000 16K cas- WARE, 6 Turning Mill Rd., Lexington, MA 02173. Amdek, Anadex, Apple & IBM accessories, Hayes, More. BUSINESS GRAPHS. ZX81 software Nine Springbrook Cir- GET SURPRISED! HARDWARE SOFTWARE ANYWARE sette $14.95. Spharler Software, ANTI -SLIP COMPUTER CUSHION. Insures accurate, vi- 95831. 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RAM, I /O, key board beep, RS232, Monitor modifi- STOCK MARKET Investment Software, Detect cycles, NDC, Dept. C8, Box 280, Carrollton, Texas 75006. cation, Data sheet, maintenance aid for Timex /Sinclair generate BUY /SELL decisions. For details contact: S.M $5.95. Add $2.00 for ham package. RAM, Port Bread- DECISIONS, Box 362, Dublin, PA 18917. TIMEX / SINCLAIR 1000/ZX81. HOW -TO Hardware up- board. MX80 Interface, program listings for VIC20 $3.95. grade book. Covering; Buffered expansion interface, Se- EPROM (2716) burner for VIC -20 or Commodore 64. In- Free product sheet. Santa Fe, 2335 S. Commerce Rd., rial output, Std. printer interface and more. $7.95. Inner cludes software on tape. $135.00 for assembled and tested Walled Lake, MI 48088. Knowledge Computers & Peripherals, 5944 N.E. Sandy for free info. JAT Electronics, Box 1222, Riverside, or ask Blvd., Portland, Oregon 97213. BEST OFFER -Basic four group CPU48K Model 4212 with CA 92502. 1 -20666 1 -12588 screens 2 -4226 discs one 4231 Printer. EXCHANGE TI -99/4A cassette programs you've created C.B. EQUIPMENT Call 305 -592 -9572. with others. Also, 8 -10 GREAT cassette programs only $5. IMPROVE CB PERFORMANCE! Modification hardware, HARD DISK DRIVE LIQUIDATION. Major OEM is liquidat- THE EXCHANGE ", CE -3, P.O. Box 46, Sterling, Virginia books, plans, Catalog $2. CBC INTERNATIONAL, Box ing inventory of unused Shugart 8" SA1002 5.33 mega- 22170. 31500PE, Phoenix, AZ 85046. hard disk drives, $380 each. Western Digital's byte VIC(5K) /BSR -X10 INTERFACE. Complete software (tape) $350. Call: LIQUIDATORS, 803 -877-9828, or CABLE TV controller. and hardware plans, $10.95. Simple to build -only two /money order to: 105 S. Main St., Greer, SC $32. Crosley, send check chips. SemiSoftware. 105 Whittier Place, Port Jefferson, CHANNEL 3 -60db notch filter. 63.5MHz. NY 12919. 29651. NY 11777. Dept. 607, Box 840, Champlain, PERSON /DEALERS WANTED for imported com- SALES VIC -20 USERS GROUP, Programs, discounts, reviews, PLANS AND KITS puter equipment /parts. Free details. WORLD ENTER- SASE, National VIC -20 Program Exchange, 102 Hickory ROBOTICS your own robot. Write now PRISES, 3227 -D Riverview Place, Columbus, OH 43202. -BOOKS -build Court, Portland, Indiana 47371. for FREE catalog! HD. Kohn /CE2, Box 16265, Alexandria, Simply plug -In. Clean, sta- VIC -20 WAVY- ELIMINATOR! COLOR COMPUTER FACSIMILE -All rates screen and VA 22302. ble computer display. $19.00. Kouh, Box 31, Gaithers- printer. Gore Software, 2023 Castleridge, San Antonio, NEW! COLOR YOUR COMPUTER'S SCREEN! Videoflex burg, MD 20877. Texas 78227. Color Kit boosts fun and efficiency. Free details, Write 16 "x20 ". For VIC20/64, DIGITIZER /GRAPHICS TABLET, PAYOFF CHARGE ACCOUNTS, credit cards, save money. Videoflex -3A, Box 149, Netcong, New Jersey 07857. Atari and all computers accepting Atari paddles. $44.95. 16K TS1000 cassette program, $12.95. JGS, 2 E. Oak Ave., ALARM SYSTEM, battery powered. Professional fea- Persimmon Peripherals, Route 2, Box 2306A -CE, Clay- Moorestown, NJ 08057. tures. Complete kit w/o chassis $59.95. Free info. Silicon ton, GA 30525. SINCLAIR- Discount programs $2.00. Send SASE for free Machines Co., P.O. Box 1536, Wahiawa, HI 96786. for our flyer of Apple APPLE BUILDERS -Send stamp listings. LDS Software, Box 999, College Station, TX 77841. parts. IC sets. ROM sets, component packages, Shu- MAILING LISTS gart -Apple modification kits, Apple 9 -track tape drives TI -99/4A CASSETTE GAMES. $5.00 each, any two $7.95, COMPUTER SHOW ATTENDEES N.Y., N.J.: 15,000 Hangman, etc. Electrovalue, P.O. Box 376 -P, Morris Plains, NJ 07950. 756 p &h. Moon Landing, Submarine Hunt, NAMES. $30 /M. P/S labels. For info, (201) 297 -2526. Mastmind. List. Cassette Software, 4129 Abercorn Road, phonemes. SC -01A SPEECH SYNTHESIZER CHIPS. 64 Knoxville, TN 37921. ALARMS Easily interfaced to VIC -20, Atari, IBM, etc. $27.00 plus Price BETTER EQUIPMENT, Longer Guarantee. You'll save! $2.00 shipping, prepaid. Alien Group, 27 W. 23rd Street, ZX81 GAMES, Bankman, Moon Landing $8.95 each. LA 70084. Catalog 504, refundable. AAS, 414A Lorna Square, B'ham, New York, NY 10010. list $1.00 refundable. Box 1180, Reserve, AL 35216. A/D CONVERTER BOARD FOR APPLE. 8 bit, 8 channels man- COMPUTER SOFTWARE Send $27 for kit, $10 for software (DVM, oscilloscope, strip - BURGLAR ALARM BUYERS GUIDE -Educational business opportunities everywhere. USERS GROUP, receive newsletter, programs, chart recorder), SASE for info. Inquire for Timex, Com- uals. Employment- VIC -20 Information $2.00. Security Electronics International, discounts and more. Send SASE for information. P.O. Box modore boards. HUANG & BERRY, 25 W. 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COMPUTER 12 Unbuffered TTL Digital I/O Lines Quality Software on: 1983 8 Unbuffered Analog Inputs Directory (O - 5V.) Where to find: DISk Drives, RAM Extensions. Print- DISK ers, Modems, Keyboards, Game 8 Serious Soft- 8 -Bit Analog To Digital Converter ware, Books, Periodicals, Programming Aids, and LED Status Indicators CARTRIDGE other Exciting Accessories! Clock /Calendar CASSETTE Articles on: Special applications'ike Control Cl Buffered Digital Outputs cuitry, Enhanced Graphics, Voice Generation, M uslc m.a.) Synthesis, Video Inversion, Light Pens, Joysticks. (500 Send for our free catalog etC. "[RAC Outputs - 400 V. 2 Amp clip and mail Complete Descriptions: Well tell you what it is, Zero -Crossing Optically Isolated what it does, how much it costs, and where to (IOC 24 -4 has 4 TRIAC Outputs, buy it. IOC 24 -12 has 12 TRIAC Outputs) Jampacked w /photographs: Box 10234 We knew you'd Regulated 5V. Power Source Using Eigen want to see what these products look like. So, we Austin, TX 78766 got pictures and put them in! The Power Supply Of The Systems / (512) 837 -4665 Computer Only $5.95 ... Postpaid: Programmable Peripheral Interface Sent First Class in the U.S.A. Sample Program Included Name To Order: Send check. money order. or VISA /MC number and expiration date. MN residents add 6% Description Price Address sales tax. GCM IOC 24 -4 189.95 Dealer Inquiries Welcome. Electronics, Inc. IOC 24 -12 24995 E. Arthur Brown Company P O Box 6152 CABLE 12.95 Zip Ft Smith. AR 72906 Dept TC -7 1 702 Oak Knoll Drive Checks, VISA. Alexandria, MN 56308 Ph, 612/762-8847 Phone: 501 -646 -2100 MasterCard Sorry -no COD s CIRCLE NO. UN eHtt INFUHMAIIUN r. CIRCLE NO 102 ON FREE INFORMATION CARD

GLDUCESTEF'3 VIC Home Control VIC 20 Sf,1el S1o0.o0 System CGr.1PUTEFi VIC 64 >`' S397.00 [A, all features of Promqueen less mimic mode. PLl DATASETTE $69 for the VIC 20 Software enhanced to include EPROM QC utilities, RS- 232 communication, printouts. 28 pin ZIF socket. VIC PRINTER $380 Reads, edits runs and programs all 5 volt GORE $36 O 2500 and 2700 series SNAK MAN $18 EPROMS plus variety SERPENTINE S36 of EEPROMS all without personality mod- AND MUCH MORE! ules. Commodore C- Discounts on Large Orders Control up to 256 lights & appliances 64 host computer. MasterCharge and VISA 1 -a ON, OFF ALLON ALLOFF Commands Inquire about the Accepted I levels of Brightness mimic mode capabil- Manual & rime Control Software FREE CATALOG ity in our VIC Promqueen. $299.00 Uses BSR remote switches O Name Plugs into User Pon ROM Packs Industrial quality circuit cards are socketed, solder masked. fully bypassed, and in- Address only $5995 (N) clude a ground plane for low noise operation. In- MasterCard ca VISA Accepted cludes 1 EPROM. 8K & 16K models for VIC -20 and Zip Call 215.681 -0950 to Order C -64. Specify 2732 or 2764 EPROM type. Molded GENESIS COMPUTER CORP. Cougar Computer Systems 1444 Linden Street plastic case. $39.00 1319 Bailey Ave. Add 3% aethlMem, PA 18019 GL110EETER CCIPIJTER' Buffalo, NY 14206 for

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www.americanradiohistory.comAmericanRadioHistory.Com I WILL BEAT ANY COMPETITOR'S PRICE PROVIDED IT IS NOT BELOW MY COST. Get more out of your TRY TO BEAT THESE IC PRICES: COMPUTERS Apple with the MICRO DYNAMIC RAM Buy By Direct on the Apple Serles 64K 200 ns $5.25 64K 150 ns 5.35 Vols. 1, 2, 8r 3 $24.95 64K 120 ns 5.90 Mail + $2.00 shipping each volume 16K 200 ns 1.35 EPROM 1- 800 -841 -0860 Each book includes more 2764 300 ris $6.25 than 30 programs - 2732 450 ris 4.05 Call For Your 2716 450 ns 3.20 all on DISKETTE 2532 450 ns 4.60 Discount Prices Machine Language Aids RAM STATIC IIO 6264LP -15 150 ris $60.00 Write For Free Price List Enhancements 6116P-3 150 ns 4.10 commodore EPSON Runtime Utilities 2114 200 ns 1.45 CI Graphics & Games Z80A FAMILY roeSMITH CORONA Hardware & Reference CPU, CTC, or PIO $3.39 OKIDATA DART 7.99 FRANKLIN Information DMA or SIO '0 12.50 EGLE TRS -80 To order toll free: MasterCard VISA or UPS CASH COD MICRO MANAGEMENT SYSTEMS 1- 800 -345 -8112 Prime Parts Factory New, TELEMARKET DEPT.1 2 I n PA 1- 800 -662 -2444 MICROPROCESSORS UNLIMITED 2803 Thomasville Rd. E. Cairo, Ga. MICRO INK, Dept. CE Peoria Ave 24.000 South 9t7.327.71MO BEGGS, OK. 74421 P.O. Box 6502 (918) 267-4961 Amherst, NH 03301 he avertable quantities 603489 -4330 >9ni0^ & nsur.Iance eas Cshadtces iscoo p sS. s er rvV 1Ur Vn rncc,rvrvmmnv1,...,. CIRCLE NO 106 ON FREE INFORMATION CARD l:iHl.Lt

MICROSETTE TS1000 ZX81 VIC-20 3 -Color Keyboard 51/4-Inch DISKETTES VIC -20 INTERFACING BLUE BOOK to Symbols with Single or double sided, all double Did you know that your VIC can be used control a 99¢ toy motor so effectively that it c Conversion density (SSDD, DSDD) . runs like a precision machine? Or that you can Instructions Soft sector, reinforced hub. build an accurate digital thermometer using the VIC and four par osting less than $5? CASSETTES These and oche 28 interfacing projects C Plastic TS1000 -ZX81 keyboard symbols ln

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www.americanradiohistory.comAmericanRadioHistory.Com GOT A TS -1000 ? GET STARTED WITH TAIWAN BOSS SOFTWARE Manufacturing is both cheaper =cam and quality controlled. 29 -J Are manufacturing cost cutting CASSETTE PROGRAMS FOR THE deeply into your Profits? TIMEX 1000/1500 COMPI ITERS We can save you from 25 to 35% GAMES, BUSINESS, EDUCATION, TUTORIAL Mfg part or whole. All orders accepted after exchange of ?AO*" samples. Reduce errors, fatigue We Mfg., Computer parts, Plastic, eye strain, and START YOUR OWN SOFTWARE COMPANY ON A SHOESTRING DUPLICATE I TO 50 CASSETTES WITH THE DIGITALIZER Steel, Cast Iron, & Others. debugging time MANJFIED CLEAN COPY OUTPUT, INEXPENSIVE, PROFES9ONAL CASSETTE DUPLICATING EQUIPMENT If you have a sample or a blue NEW' This Universal Pin Identifier (Patent AND WE SHOW l'()L, f I(í11" Pending) identifies the pins of 40 -pin, 28 -pin, print, write for a quotation to: 24 -pin integrated circuits on the front side. The back side identifies the pins of 22 -pin. 20- pin. 18 -pin, 16 -pin and 14 -pin integrated cir- G.S.0 IMPORT & EXPORT o. cuits. Just press the side notches against the WRITE FOR FREE CATALOG I.G. pins to locate the pin numbers. Use it for Products Research & Mfg. wire -wrapping and debugging. Every hard- EULYN ENTERPRISES ware designer should have one. Only $3.50 4N 650 RIDGEWOOD P.O. Box 901 plus 450 for shipping and handling Texas res- l..-r.. BENSENVILLE, IL., 60106 idents add 5% sales tax So. Pasadena, CA 91030 (312) 832-1599 CREATIVE DEVICES Telex: 295385 GSCC UR P.O. Box 49184 Austin, TX 78765

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COMMODORE Texas Instruments POWER LINE PROBLEMS? OWNERS! Atari 400, 800, and the new 1200XL Commodore 64, Vic 20, New Releases From Eagle, ACE 1000, Hewlett Packard, Kaypro II Osborne, Home Software Co. Sanyo, Otrona, NEC, Columbia, Data, Altos, Amdek, Okidata SPIKE- SPIKERSTM...The Solution! Nutridatia - food value program Minimize equipment damaging spikes and conducted RF noise -free for low prices and to or from sensitive equipment. Transient surge protection The Wizard - 5 level math tutor Call us toll friendly service. plus low pass RFI hash filtering. All units 120V I SA. Mediguide - home health aid Full line of hardware and software. MINI II $44.95 Wall Mount The Black Book - phone list Fast most orders shipped service - 3 -stage filter Compucise - exercise guide within 24 hours. 2 sockets -Tape 17.50 -Disk Toll -free 800 -327 -8133 QUAD II $59.95 13.95 Wall mount Dual 3 -stage filter In FL 305-266 -5981 9AM - 6PM EST FREE BROCHURES DELUXE $79.95 d sockets R. light InterContinental Computer Dual 5 -stage filtered ,kts B switch sockets Home Software Co. 5724 SW 20 Street, Miami, FL, 33155 molo switch, fuse light 0110 Factory Direct P.O. Box 206 All our products are new warranted Kalglo Electronics Co., Inc. Order 65 84 Ruch Rd. Dept C E 215- 837 -0700 Bridgewater, VA equipment. Please call for handling Bethlehem. PA 18017 Out of Stale charges or C.O.D. Non certified checks (703) 434 -8418 DEALERS INVITED 800. 523.9685 allow 1 to 2 weeks to clear PA Res Add 6°. COD odd 13 00 + Shipping for useful home software CIRCLE NO 118 ON FREE INFORMATION CARD CIRCLE NO. 118 ON FREE INFORMATION CIRCLE NO. 119 ON FREE INFORMATION CARD

_ LEO ELECTRONICS, INC. Put 64K CP/M /2 8921 S. Sepulveda w 208 Los Angeles, CA. 90045 ;213) 641 -3101 1800/ 421 -2418 in your TRS -80 /, 41.. TLX: 664 -688 Interline LSA FREE Model III Our plug -in Shuffle board III comes with I 6K LOOK!! and gives you the full CATALOG! power of 64K CP/M 2.2, the industry standard LOW PRICES operating system. Tap into over 2,000 off- he-shelf business programs Just let us know and we'll mail such as dBASE II. SuperCa c. WordStar. etc. HAMS EPROMS READ /WRITE and RUN software from Osborne. you a FREE Creative Comput- 4116 1200ns1 1.10 2708 2.50 Xerox, Superbrain. Kaypro II. HP 125 and TeleVideo. filled 4116 115Ons! 1.25 2716 3.20 You can even READ/WRITE IBM PC software for ing Catalog -16 pages 4164 (20Ons, 4.65 2716-1 5.00 CP /M 86. with books, buyer's guides, 4164 1150ns :, 4.85 TMS 2716 4.75 Simple to install. Shuffleboard III plugs into two 2114 1200ns; 1.50 2732 3.95 inside your Model III. No permanent 4.50 existing sockets magazines, and more! 6116P-3 4.25 2532 no cut traces. no soldering. You'll be 2764 8.00 modifications, MICROPROCESSORS up and running in minutes. For only 5299. Includes a manual and a first FREE catalog, REGULATORS MBASIC Interpreter, software rib get your Z-80A 4.50 class users manual. Coming soon: an 80 x 24 8080A 2.75 ALL .75 Video Board and a Floppy Disk Controller. write to: Creative Computing 8085A 6.00 TO -220 See the Shuffleboard at your local computer NA1X 39 East store or order directly from us. Credit card orders Catalog, Dept TERMS: Check, Visa, Mastercard. Call for C.O.D. shipped directly from stock. Sorry, no CODs. Free U.S. Funds only. California residents add 6%% sales tax. I Hanover Ave., Morris Plains, SHIPPING: Add 52.00 for Ground and $5.00 for Air. page brochure. Call (415) 483 -1008 ALL MAJOR MANUFACTURERS NJ 07950. ffmamorp - ALL PARTS 100% GUARANTEED i/ìmarchant a,.. s.nr...,..van,,,

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www.americanradiohistory.comAmericanRadioHistory.Com C °m VI Zo THE PEOPLE'S COMPUTER bS SUPPLY OUR TIME% SINCIIR I %LDRI 5 (COLER IT LOOMS LIKE TOY BUT DON'T LIT LOOKS FOOL YOU' TRY SOME Of OUR D ONS L SE[ WHAT Software RADIO SHACK YOU CAN REALLY DO WITH THE FOOLER HERE AR[ TUST FEW OF OUR HARDWARE ITEMS MEMOT[CH PRODUCTS FREE TRS- 80'sTM 64K MEMOPAK 33l PREMOLAR '9S" We offer Special Discounts, Free Shipping UK MEMOPAK and a Toll Free Order Number HIGH RESOLUTION GRPHKS W S" CATALOGUE IL SIIE DIRECT CONNECT KEYLOARD No oMe,. +9 plugs Into Ng eonnees, DEALER INQUIRIES WELCOME MAKE IT TALK TO YOU WILLIAM STUART SYSTEMS SPEECH 1.800-531.7466 TOLL FREE YNTHESIS

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R.I.S.T. INC. ANNOUNCES ARBITRARY WAVEFORM TIMEX/SINCLRIR ZX/91 GENERATOR ONLY $345! F R E aoSñx Q ! róIT1EX P.O. Box 50 Purchase Esÿ Generate any custom waveform A Parrot Speech Synthesizer, receive: Utica, MI with the Apple Computer. SPEECH SYNTHESIZER in T.L. 48087 analog and digital outputs A Subscription to SQ "$15. VALUE FREE" up to 20 volts p-p output Phrase Finder Program "$5. VALUE FREE" Full Size Speech Synthesis Manual "$10. VALUE FREE" 43 Key 125 ns /pt- 1 sec /pt `ACT NOW: Receive Poker Game Cartridge Keyboard up to 2048 points "$15. VALUE FREE" 8 bit resolution with TIMEX /SINCLAIR - Speech Synthesizer FUNC- plug -in module. FREE subscription 89.95 Single Key1=1 Selection of to SO, TALKING Poker Game Cartridge +4.sh TION, SHIFT LOCK and GRAPHIC Phrase Finder Cart., Speech Manual MODES. 2 LED Mode Indicators T/S Speech Synthesizer Kit comp!- 59.95 Simple Plug In Installation with PC Board & all components. +3.sh Fully Enclosed . . only 59.95 +; APPLE 11, 11 TRS80 I, Ill, Color; PRCK VIC -20 Speech Synthesis Starter 34.95 64 K RAM .... '99.95 Kits. ALL KITS include Free: +2.sh 16 K RRM PRCK '39.95 I=1 Subscription to Computer Shopper, Keyboard Speech Manual, Phrase Finder List. (case & numeric pad) '99.95 CI 9v, 2amp POWER SUPPLY for the T/S 24.95 Seikosha GP 100 printer and interface SURGE FREE transient absorber, +2.sh for Sinclair '369.00 eliminates destructive surges. 2 Hi Res Graphics Board . '49.95 socket - 69.95, 6 socket - 89.95, 10 socket - 99,95. Add $3.00 S /H. 16 K SOFTWARE '9.95 Inquire about our complete line Horse Master Panzer SS Ai Pacific of TALKING Software Programs. Bill Master Budget Master ' ' 10 Day Money -Back Guarantee Appointment Planner

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$1,295.00 Z -80 -6502 TRS -80 COMPUTER SYSTEM COMPUTER DISK DRIVE, DRIVE CARD, MONITOR

DISCOUNTS SYSCOM' $550.00 ORANGE' $650.00 Factory Direct FRANKLIN CALL Best Prices Anywhere GEMINI 10 $375.00 No Out -of -State Taxes Hayes Micrornodem $275.Incredible Jack $100. Slimline Drive $255.Regular Drive $245. 100% Radio Shack Warranty 80 Col. Card $1102 -80 Card $100 Free Price List Cooling Fan $55.Syscom' Bare Board $55. Disk Drive Card $6516K Card $65 Parallel Printer Card $65. SCOTT TASSO ASSOCIATES !! WE WILL BEAT ANY PRICE!! 175 North Delsea Drive Softsell Systems 14 E. 34th St. NY, NY 10016 Vineland, N.J. 08360 9600 Roosevelt Blvd., Suite 100, LL 800- 257 -0426 212-685-2080 Philadelphia, Pa. 19115 NJ 609-691-7100 i (215) 665 -5639 rlor`I C un s99 roa FOCF INCnRN4TInN !'AOn CIRCLE NO t28 ON FREE INFORMATION CARD CIRCLE NO 129 ON FREE INFORMATION CARD

www.americanradiohistory.comAmericanRadioHistory.Com TOROIDAL POWER TRANSFORMERS ©OAS 1SETTE Small size Low noise Easy mounting Ideal for audio Precision 5 Screw Cassette amps, CRT monitors and computers 103/4 x 714 x 21R Premium Quality Tape where low hum is re- Labeled Both Sides For -r Individually Boxed Includes mounting wash - Your Freight Paid On All Orders II er with center hole for ZX81/ Guaranteed Against Defects screw. Examples of 117V-60Hz transformers in stock: TS1000 COMPUSETTE COMPUSETTE + (5 MIN. PER SIDE) (10 MIN PER SIDE) s6: -WNBM s.condariss Unit pica In qty 25 $20.00 (80') $22.50 (90') OD :H Vole/Current 1 2-4 100 $70.00 (70`) $80.00 (80 °) 2x8.5V/2.3A Easy To Install 500 $330.00 (66 °) $365.00 (73 °) 40VA -1.1 Iba 2412V/1.67A $29.00 924.40 No Soktenng - No Modifications 2.8'x1.3" 2x15V/1.33A OUT OF STATE (800)527-1227 2x24V/.83A 41 Keys with Full Size Space Bar Allows Touch Typing Same Key Layouts as Sinclair Two Cola Keytops TEXAS (214)349.0081 C.O.D. 2x8.5V/5.8A Keyboard Case Holds Both Keyboard aid Computer 100VA-2.2 lbs 2x12V/4.1A 833.00 828.60 Commands and Graphics Spelled Out on Keytops 3.7 "x1.4" 2x15V/3.3A Rear Cutout for Any RAM or Expansion (Modules W 2x18V/2.7A PN MP 16 EACH 220V/1.55A $53.60 046.50 16K Piggyback RAM Module $49.95 340VÁ -3.3 Iles CASSETTE TEXAS 2x24V/7.1AA I INCLUDES RESIDENTS 4.5 "x2.3" $56.50 046.50 COU, 7NC. I - SUNTRONICS A NORELCO ADD` 'Mny be used separately, in parallel, or in series. le Cald Call 213- 644 -1149 CONTAINER SAI Call to order or write for listing of off- the -shelf toroidal trans- calif cat -5775 - oueds 1- 800 -421 BUY NOW SAVE 10% formers 20VA -600VA Or send Check or MO to Tema: C.O.D., VISA, MASTERCARD or Money Order r_ IF it ECK OR MONEY ORDER ACCOMPANIES Shipping: Add 91.00/lbs for UPS 1 +01.50 for C.O.D.). mom. si P.O. Box 1951 Hawthorne CA 90250 .6000"iß I nrn">. California Indents add 61/2% sales tas P.O.BOX 38851 DALLAS, TX 75238 1301) 459 5890 Add S4 00 shp'haidhng. NSA /Masterard include rnpkaaon date 4720 ¿ Boston Way, Lanham, MD 20706

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COMPUTER 64K INSIDE!! COMPUTER MART Zx81 CASSETTES T/S1000 FORMAT No wobbles! No bulky add -ons! BASF No fear of crashing if bumped! 2" X 3" The 64KT and 64KZ are 64k of user transparent -DIPS memory which mount INSIDE the TS1000 or ZX81 THE WORLD'S FINEST (respectfully). Data media for all microcomputers. In Installs in aminute with NO soldering, and easy to Used nationwide by software manufac- follow instructions. Of, if you prefer get the memory turers, hobbyists, schools and bush, you want in a kit that you can put together. all the parts needed are included. nesses. Premium 5 -screw shell with leader fits all standard recorders. PICTURE YOUR AD HERE! The 64KT = TS1000 witrh ser. no. prefix F or P SATISFACTION GUARANTEED OR MONEY BACK. The 64KZ = TS1000 with sere no. T or D or ZX81 Send for free brochure. Ad Ion ITEM 1 DOL 2002. quantity dustmen.. COI. mu- 6410. or64KZ 115.00 C-05 7.50 L, 13.50 denls add aale tae. SHIPPING 64KTK or 64KZK (kit) 90.00 HANDLING (UPS) I dos. $2 0.00 14.40 C-10 2 I dos. 04.50. ea dot. 53.50: NEXT CLOSING DATE: number you need, and For 'nisei To order, send the part C-20 0 10.00 0 18.00 additional dos. 5.50. for shipping and pod instead al UPS add $1 Check or motley Order (add 4.00 ons 2.50 4.00 Hard Oubide ContinunnIUSA. add D. handling) to: FOR IMMEDIATE SHIPMENT AUG 3 lar roue nit 011 aAS1EacAao CALL 213/710 1430 INDEPENDENCE RESEARCH P.O. BOX 1497 YORK 10 "Computerware OREM, UTAH 84057

24573 ICIInkle SI p I Canoga Park CA 91307 FOFF INFORMATION CARD CIRCLE NO. 136 ON FREE INFORMA N - D CIRCLE NO. 137 ON www.americanradiohistory.comAmericanRadioHistory.Com ComInitersalectronics EPROM Programmer Shelf

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