adio HOW TO BUY A CD PLAYER JANUARY 1990 ECHNOLOGY - VIDEO - STEREO - COMPUTERS - SERVICE BUILD R-E's ACOUSTIC FIELD GENERATOR ransform your living room vith movie-theater sound! WILD A PHONE-ACTIVATED WDIO-MUTING CIRCUIT lever miss a phone call gain — no matter how oud you play your stereo! JUILD A SIMPLE OGIC ANALYZER < .OW TO FIGHT ESD 3 rotect your equipment ind components from lectrostatic discharge omputerDicest uildthe Port-A-Matic nd keep track of four computer's ports! $2.25 U.S. $2.75 CAN SUE ^^ ER Lfc.EL tHz CUT \ CENTER \ POWEF c$ k © k publication FLUKE AND PHILIPS - THE GLOBAL ALLIANCE IN TEST & MEASUREMENT FLUK PHILIPS (if n^t» nm^f £**»c en r\\\7 naif tnp mVfnrp The new Fluke 45 has dual display versatility. With 2 multifunction displays and 16 dif- ferent measurement capabilities, the new Fluke 45 does virtu- ally everything you want a meter to do. And for a surprisingly affordable price. I ^<5H® ■ The 5-dlglt, 100,000 count dual dis- plays give you more information in less time — and with less etfort. For example, measure the VOC output of a power sup- ply while measuring the VAC ripple. Or check the amplitude and frequency of an AC signal. From a single test connection! And the Fluke 45 is designed to make complex measurements easier, with stan- dard features like a 1 MHz frequency counter, Min Max, limits testing (Hi/Lo/ Pass), Touch Hold* and Relative modes. There are 21 different reference imped- ances for dB measurements; in the 2 a to16n ranges, audio power can be auto- matically displayed in watts. ?C,33 - q e a o 77] |7T| Q T^^ W (Wi ) Get everything you've ever wanted. Dual displays. 16 functions, Even the security of an optional two-year warranty extension for only $35. For all the information on the new Fluke 45, contact your local dis- tributor. Or call toll-free 1-80Q-44-FUIKE,ext.33. Accuracy to get the fob done right. The Fluke 45 is a true-rms meter, with 0.02% basic dc voltage accuracy and 100,000 count resolution on both displays. Basic dc current accuracy is 0.05%, making the 45 ideal for servicing 4-20 mA current loops. Closed-case calibration simplifies the calibration process and increases uptime. Even an RS-232 interface is standard. Connecting the Fluke 45 to PCs, RS-232 printers and modems is as easy as attaching the cable. An IEEE-488,2 Interface and rechargeable batteries are available as options. CIRCLE 121 ON FREE INFORMATION CARD FLUKE 45 DUAL DISPLAY MULTIMETER S595* Dual Display True-rms voltage and current. including ac+oe 0.32% L-asio Cc yj la tie accuracy 0.05% basic lie current accuracy 1 MHz frequency counter FlS-232 interface standard t)B.witti21 reference impedances, arid audio power calculations. •SurjrjestedU.S. List Price Compare and Relative lunctions Min Max and Toucti Hold' Junctions Optional PC sol twa re lor R S-2 32 applications Oolional IEEE-488.2 interface. battery pack One year warranty Optional two year warranty eiiension S35* join Fluke Mia Co. inc. BB, am C9090 M/S250C Eieieir. m 98206 J.S.. 2O6-356-5400 Cauda: 415-890-7500 Oilier Countries: 206-356-6500 ©Ccwriohl 1959 John Fluke M1g Co.. Inc. All rights reserved. IBM PC is a registered trademark ol International Business Machines Corooratioi M No 059 IF 45. FLUK January 1990 Electronics Vol. 61 No. 1 BUILD THIS 36 ACOUSTIC FIELD GENERATOR Bring high-quality, multichannel surround sound into your living room. Tod T. Templin 41 3-CHIP LOGIC ANALYZER Build this 8-bit word-recognition logic analyzer for only six dollars! J.J. Robinson II 43 PHONE-ACTIVATED AUDIO MUTING CIRCUIT Let your telephone's ringer automatically shut off the sound on your stereo or TV. Mark A. Vaitght ComputerDicbst 45 WHAT'S NEW IN CD PLAYERS A consumers guide to the latest CD technology. Josef Bernard 54 ELECTROSTATIC DISCHARGE How to prevent ESD from damaging your components. Dave Hollander m PAGE 81 1969 ANNUAL INDEX Volume 60 ana Volume 6 . ■ -. 81 BUILD THE PORTA MATIC Keep tabs on your expansion bus. Robert Grossblatt ':<■ The 1989 Annual Index begins on page 57. I.UJM'.M!I,« I H:V'|ii;,lll;l:.^H 6 VIDEO NEWS What's new in this fast- 71 73 79 81 AUDIO UPDATE The Audio Answerman strikes again! Larry Klein SHORTWAVE RADIO The future of shortwave broadcasting. Stanley Leinwoll DRAWING BOARD The world of video. Robert Grossblatt EDITOR'S WORKBENCH Floppy heaven. Jeff Holtzman changing field. David Lachenbruch 22 EQUIPMENT REPORTS Hameg HM8028 Spectrum Analyzer and Elenco Micro- Master 8000 Microprocessor Training System. 61 HARDWARE HACKER The science of Chaos. Don Lancaster 108 Advertising and Sales Offices 108 Advertising Index 12 Ask RE 109 Free Information Card 16 Letters 92 Market Center 26 New Products 4 What's News i to o 1 z o t- o LU 6 D < Chances are you've already joined the hoards of people who have abandoned the long lines and high prices of local movie houses for the convenience and comfort of their favorite armchairs? Now, if onlythefilmsyouwatchonyourVCR sounded as good as they look. . . Enter our Acoustic Field Gener- ator, which goes a couple of steps past the standard surround-sound decoder project. The apparent sepa- ration of the stereo image from the front speakers is greatly increased, while a center dialogue channel keeps the actors' voices realistically near the screen. The AFG is simple to connect into the pre-amp/power- amp loop of your home-entertain- ment system, and the built-in 75-Hz active low-pass filter provides a sub- woofer output. Turn to page 35. THE FEBRUARY ISSUE GOES ON SALE JANUARY 2. BUILD A FREQUENCY PROBE Our easy-to-build, 100-MHz frequency counter is the size of a logic probe. THE PRIVATE EYE All about a new miniature display that promises to revolutionize the computer, videogame, and maybe even the TV marketplace. BUILD A RADAR- DETECTOR TESTER Is your radar detector working properly? Test it with our transmitter. CIRCUIT COOKBOOK How to use dual audio-preamplifier IC's for pre-amps, playback amps, audio mixers, filters, and more! GomputerDigest Get the construction details for the Port-A-Matic. As a service to readers, RADIO-ELECTRONICS publishes available plans or information relating to newsworthy products, techniques and scientific and technological developments. Because of possible variances in the quality and condition of materials and workmanship used by readers, RADIO-ELECTRONICS disclaims any responsibility for the safe and proper functioning of reader-built projects based upon or from plans or information published in this magazine. Since some of the equipment and circuitry described in RADIO-ELECTRONICS may relate to or be covered by U.S. patents, RADIO-ELECTRONICS disclaims any liability for the infringement of such patents by the making, using, or selling of any such equipment or circuitry, and suggests that anyone interested in such projects consults patent attorney. RADIO-ELECTRONICS, (ISSN 0033-7862) January 1990. Published monthly by Gernsback Publications. Inc., 500-B Bi -County Boulevard, Farmingdale, NV 11735 Second-Class Postage paid at Farmingdaie. NY and additional mailing offices. Second-Class mail registration No 9242 authorized at Toronto, Canada. One-ycar subscription rate U.S.A. and possessions $1 7 97 . Canada S23.97. all other countries $20.97. All subscription orders payable in U.S.A. funds only, via international postal money order or check drawn on a U.S.A. bank. Single copies $2.25. r - 1989 by Gernsback Publications, Inc. AM rights reserved. Printed in U.S.A. POSTM ASTER: Please send address changes to RADIO-ELECTRONICS. Subscription Oept . Boa SSI IS Boulder CO 80321-5115. A stamped self-addressed envelope must accompany all submitted manuscripts an d/or artwork or photographs if their return is desired should they be rejected. We disclaim any responsibility for the loss or damage of manuscripts and/or artwork or photographs while in our possession or otherwise. Electronics Hugo Gernsback (1884-1967) founder M. Harvey Gernsback. editQT'irvchifif, emeritus Larry Stechler, €KF, GET. editor-in-chief and publisher EDITORIAL DEPARTMENT Brian C. Fenton, editor Marc Spiwak, associate editor Daniel Goodman, technical editor Teri Scaduto. assistant Editor Jeffrey K. Hottzman computer editor Robert Grossblatt, circuits editor Larry Klein, audio editor David Lachenbruch contributing editor Don Lancaster contributing editor Richard D, Fitch contributing editor Kathy Campbell, editorial assistant ART DEPARTMENT Andre Duiant, art director Injae Lee, illustrator Russell C. Truelson, illustrator PRODUCTION DEPARTMENT Ruby M. Yee, production director Robert A. W Lowndes, editorial production Karen S. Tucker advertising production MarceNa Amoroso production assistant CIRCULATION DEPARTMENT Jacqueline P. Cheeseboro circulation director Wendy Alanko circulation analyst Theresa Lombards circulation assistant Michele Torrillo. reprint bookstore Typography by Mates Graphics Cover photo by Diversified Photo Services Illustration by Del Studios Radio-Electronics is indexed in Applied Science A Technology Index and Readers Guide to Periodical Liter- ature, Microfilm & Microfiche editions are available. Contact circulation depart- ment for details. Advertising Sates Offices listed on page 108. m & The Audi! Bureau oi Circulation COAX ADAPTER KIT ■ Create any adapter in seconds ■ Make all combinations of BNC, TNC, SMA, N, UHF. Mini-UHF, F and RCA The TPI 3000A kit contains male and female connectors of all 8 types, and 6 universal inter- faces. Simply screw any combination of 24 con- nectors to one of the interfaces to create the desired adapter. $150. TEST PROBES INC. 9178 Brown Deer, San Diego, California 92 1 2 1 . Call toll-free for cata- log: 1-800-368-5719. CIRCLE 250 ON FREE INFORMATION CARD DELUXE TEST LEAD KIT Users call TPI test leads The Absolute Best. The TLS2000 features the highest quality cable in the industry — with spring-loaded safety-sleeved plugs. U.L. listed (file E79581). Kit: $29. Leads & probes only: $19. Satisfaction guaranteed. TEST PROBES INC. Call toll-free for catalog: 1-800-368-5719. CIRCLE 251 ON FREE INFORMATION CARD VMHI 1 T T T T T 1 HHH I BNC ATTENUATOR KIT Contains 4 attenuators — 3dB, 6dB, lOdB, 20dB; I feedthrough and 1 termination. Thick- film circuitry for low reactances. Rugged de- sign resists shock and lasts longer. Rectangular shapestays put on the bench. Impedance: 50ii Frequency: 1GH/.. Maximum Power: IkW peak, 1W avg. VSWR 1.2:1. Attenuator Accuracy:±0.2dB. Terminations Resistance Tolerance: ±1%. $150. TEST PROBES INC. Call toll-free for catalog: 1-800-368-5719. CIRCLE 252 ON FREE INFORMATION CARD ECONOMICAL SILICON RUBBER TEST LEADS Best value in moderately priced leads. High quality, soft, silicon rubber cable. Banana plug on measuring tip accepts push-on accessories. Plugs have spring-loaded safety sleeves. Mode! TL1000 $14. Satisfaction guaranteed. TEST PROBES INC. Call toll-free for catalog: 1-800-368-5719. CIRCLE 253 ON FREE INFORMATION CARD No Better Probe Ever at This Price! Shown here Model SP150 $/IQ Switchable lx-lOx ...7*^ CIRCLE 254 ON FREE INFORMATION CARD Risetime less than 1.5 nsec. Universal - works with all oscilloscopes Removable Ground Lead Excludes External Interference - even on scope's most sensitive range ■ Rugged - withstands harsh environments including high temperature and humidity < Advanced Strain Relief - cables last longer • Available in lOx, lx and switchable lx-lOx Call for free catalog and • 10 day return policy - performance and satisfaction guaranteed TEST PROBES, INC. iTPI 9178 Brown Deer Road San Diego, CA 92121 Toll Free 1-800-368-5719 l-800-643-83S2inCA Distributor in your area CIRCLE 123 ON FREE INFORMATION CARD Z C > < to o WHAT'S N EWS 20%-efficient solar module SANDIA RESEARCHERS CLEMENT CHIANG AND ELIZABETH RICHARDS show the experimental photovoltaic concentrator used to achieve a record-breaking 20.3 peak solar-to-electric conversion efficiency. Twenty-percent efficiency might not be considered impressive in most instances, but when it means that 20% of the solar energy falling on a solar concentrator module is being converted directly into elec- tric energy, that figure takes on new dimensions. The photovoltaic concentrator module developed by researchers at Sandia National Laboratories — an arrangement of 12 plastic lenses that concentrate sunlight to 100 times its normal level onto 12 silicon solar cells — has achieved a peak solar-to-elec- tric conversion of 20.3%. The module incorporates a new silicon concentrator cell with up to 25% efficiency and a transparent ceil cover molded directly to the cells to reduce gridline reflection losses. A new technique of solder- ing cells directly to copper heat spreaders reduces costs and im- proves performance and re- liability, and an anti-reflective coat- ing improves lens efficiency. The key to the module's econo- my is the lens, which can multiply the intensity of the sun several- hundred times and focus it on a cell. The module uses an essen- tially module-ready, about half-an- inch square, low-resistivity cell that was developed by Martin Green at the University of New South Wales in Australia. A pris- matic cell cover deals with the problem caused by the thin metal gridlines — which carry current from the cell but also block sun- light from falling on (he silicon cell surface — by bending sunlight away from the gridlines to the sil- icon surface. That allows the use of wider gridlines that carry current, generated from cells, more easily. A low-cost method was developed for cleaning the surfaces and sol- dering them together, allowing the cells to be soldered directly to the heat spreader beneath them, elim- inating a ceramic insulator that separates them in conventional modules. Finally, an anti-reflective layer of magnesium fluoride solu- tion was applied to both surfaces. According to Eldon C. Boes, su- pervisor of Sandia's Photovoltaic Technology Division, "Industry should be able to duplicate most of these features very quickly." Possible initial uses are in pilot power plants at utility companies and small, 10- to 1000-kilowatt stand-alone power systems, (A 1000-kW system will meet the elec- trical requirements of about 300 homes.) Boes expects concen- trator modules incorporating the innovations to be on the market within about three years. V) z O cc h- O LU _l LU Q < High quality AM sound The National Association of Broadcasters and the Consumer Electronics Group of the Electronic Industries Association have agreed to enter a joint program to promote high-quality AM sound using the standards of the National Radio Standards Committee or NRSC. The NRSC standards im- prove AM radio transmission and reception quality and reduce inter- ference between stations, thus im- proving the quality of sound. The first task for the groups is to establish a certification mark or logo that will be used on the face- place of high-quality AM receivers that are equipped to comply with NRSC deemphasis and bandwidth specifications. R-E WITH CIE, THE WORLD OF ELECTRONICS CAN BE YOUR WORLD, TOO. Look at the world as it was 20 years ago and as it is today. Now, try to name another field that's grown faster in those 20 years than electronics. Everywhere you look, you'll find electronics in action. In industry, aerospace, business, medicine, science, government, communications— you name it. And as high technology grows, electronics will grow. Which means few other fields. U any, offer more career opportunities, more job security, more room for advancement — if you have the right skills, SPECIALISTS NEED SPECIALIZED TRAINING. It stands to reason that you leam anything best from a specialist, and CIE is the largest independent home study school specializing exclusively in electronics, with a record that speaks for itself. According to a recent survey, 92% of CIE graduates are employed in electronics or a closely related field. When you're investing your time and money, you deserve results like that. INDEPENDENT STUDY BACKED BY PERSONAL ATTENTION. We believe in independent study because it puts you in a classroom of one. So you can study where and when you want. At your pace, not somebody else's. And with over 50 years of experience, we've developed proven programs to give you the support such study demands. Programs that give you the theory you need backed with practical experience using some of the most sophisticated electronics tools available anywhere, including our Microprocessor Training Laboratory with 4K of random access memory. Of course, if you ever have a question or problem, our instructors are only a phone call away. START WHERE YOU WANT, GO AS FAR AS YOU WANT. CIE's broad range of entry, intermediate, and advanced level courses In a variety of career areas gives you many options. Start with the Career Course that best suits your talents and interests and go as far as you want — all the way, if you wish, to your Associate in Applied Science Degree in Electronics Engineering Technology. But wherever you start, the time to start is now. Simply use the coupon below to send for your FREE CIE catalog and complete package of career information. Or phone us, toll-free, at 1-800-321-2155 (in Ohio, 1-800-523-9109). Don't wait, ask for your free catalog now. After all, there's a whole world of electronics out there waiting for you CIE Cleveland Institute of Electronics, Inc. 177 E East 17th Street, Cleveland, Ohio 44114 Member NHSC Accredited Member National Home Study Council CIE Cleveland Institute of Electronics, Inc. 1776 Ease 17th Street, Cleveland, Ohio 4AV\A ARE-156 VESim I want to leam from the specialists in electronics— CIE, Please send me my FREE CIE school catalog, including details about CIE's Associate Degree program, plus my FREE package of home study information. Name (print): Address: City:. Age: State: Zip: Area Code/Phone No: /_ Check box for G.I. Bill bulletin on educational benefits: MAIL □ Veteran D Active Duty TODAY! o z o EC h- O LU D < Video News • Zenith sticks with TV. After a long and fruitless effort to sell its consumer-electronics business, Zenith, in a sudden move, agreed to sell its computer business to Group e Bull of France. The company said that the move will enable it to strengthen its "original core business" of making and selling TV sets and its work on high- definition TV. The pioneering company now says that it is renewing its commitment to TV and video. Zenith plans to build on its longtime strengths in "consumer electronics and display technologies," according to President Jerry Pearlman. Since the sale of the RCA and GE television business to Thomson of France, Zenith has been the only major American-owned TV manufacturer. • LCD developments. Japanese manufacturers and government agencies appear convinced that the liquid-crystal device will be the ultimate successor to the cathode ray tube as the direct-view and projection-display system for television. Two major Japanese-government- backed projects are aimed at that goal. JTV, a consortium consisting of 17 private companies with the backing of the Ministry of International Trade and Industry (MITI), has a goal of developing a 40-inch flat-screen color display with a resolution of 6,000,000 pixels. The other group, HDTEC, consists of five private firms and the Post Ministry, and is charged with developing a 50-inch rear-projection system with a resolution of 2,000,000 pixels and a light source four times the brightness of a CRT, HDTEC is capitalized at $24,500,000; JTV, at $20,000,000, • Pay to view as yon fly. The airlines have figured out a new way to keep you spending while you fly. Lockheed is demonstrating to its aviation customers an in-flight entertainment system consisting of a seat-back LCD color display — with a slot for credit cards. The system can provide eight channels of movies or video games that can be paid for by sliding a card through the slot. In addition, the system includes special films advertising products that can be ordered by touching the screen at the proper time and using the credit card. Before you can change your DATED LACHENBRUCH, C0]SFTRIBTJTIH"G EDITOR mind— while the aircraft is still in flight — an on- board computer sends your order by satellite to an on-the-ground sales center, which tallies your bill for watching the movie and for any purchases and dispatches it to your home by mail — perhaps even before you land. • EDTV broadcasting starts. "Clearvision,'* Japan's Extended- Definition Television (EDTV) system is now being broadcast for five hours each day by many of that country's stations. The compatible system results in an improved picture on Clearvision television receivers without affecting the image on standard sets. The current "Phase I" Clearvision system, employing the standard 4:3 aspect ratio, involves the following improvements at the TV station: (1) better camera performance through the use of high- definition or progressive-scan cameras, with the improved signal downcoverted to a standard interlaced NTSC-eompatible signal; (2) gamma correction to improve color, particularly at high saturation levels; (3) picture sharpness and signal -to -noise ratio improved by "adaptive emphasis;" and (4) ghost-canceling reference signal. Clearvision receivers improve the signal by using 3-D comb filters for Y/C separation, and use digital memory to convert the interlace picture to progressive scan. They might also have an optional ghost-reduction circuit, which eliminates ghosts by comparing the received waveform with the transmitted waveform carried on the reference signal (sent on line 18 of the vertical interval). Ghost reducers, which work with standard as well as Clearvision sets, are also available as add-on "black-box" attachments. The Japanese ghost-canceling system is one of several being explored for use in the United States Radio-Electronics, Video News, November 1989). Phase II of Clearvision is expected to use a widescreen 16:9 aspect ratio, extension of chrominance- and luminance-signal bandwidth, and PCM digital audio — without sacrificing compatibility. There's no timetable yet for that second phase. B-E matter where you go, new 222 is a perfect fit. No Tek'snew222 Introducing Tek's new 222 Digital Oscilloscope, Weighing in at under 4.5 pounds, the new Tek 222 is an ultra-portable, 10-MHz digital storage scope that's perfect tor service applications. So tough, rugged, and totally self-contained, it can go just about anywhere. And it's incredibly easy to use — even in extreme conditions. Extraordinary capability and reliability at a great price. The 222 is a dual-channel scope that can measure a wide variety of electronic instrumentation and circuitry. It has rechargeable on- board batteries with a floating ground to 400 volts, and meets tough environmental standards. Plus, the 222 lets you pre-define front-pane! setups, and call them up with a single button in the field. You can also save waveforms in the scope's memory then transfer them to a PC for analysis and hard-copy output when you get back to the shop. Best of all, the 222 is yours for only $2350. And that includes Tek's remarkable three-year warranty on parts, labor, and CRT Get one to go! Pack a handful of power with you wherever you go, To order your 222, or for a free bro- chure, contact your local Tek rep- resentative or authorized I distributor. In a hurry? Call 1-800-426-2200. Ttektronix CCMMFTTED TO EXCELLENCE l 19EH Teklranu Ire All r^nis'EHfved ftrMj aib^CJ to cnangt *»inDul rake > c > < CD CD O CIRCLE 145 ON FREE INFORMATION CARD No other training— anywhere— shows you service computers . NEW! ■ Hard drive and voice synthesis training , included! Only NRI walks you through the step-by- step assembly of a powerful XT-compatible computer system you keep— giving you the hands-on experience you need to work with, troubleshoot, and service all of today's^ most widely used computer systems. - c ^ With NRI at-home training, you get everything you need to start a money-making career, even a computer service business of your own. No doubt about it, The best way to learn to service computers is to actually builds state-of-the-art computer from the keyboard on up. As you put the machine together, performing key tests and demonstrations at each stage of assembly, you see for yourself how each part of it works, what can go wrong, and how you can fix it. Only NRI, the leader in career- building electronics training for more than 75 years, gives you such practical, real -world computer servicing experience. Indeed, no other training — in school, on the job, anywhere — shows you how to troubleshoot and service computers like NRI. You get in-demand computer skills as you train with your own XT-compatible system— now with 20 meg hard drive and640KRAM With NRI's exclusive hands-on training, you actually build and keep the powerful new Packard Bell VX88 PC/XT compatible computer, complete with 640K RAM and 20 meg hard disk drive. You start by assembling and testing the "intelligent" keyboard, move on to test the circuitry on the main logic board, install the power supply and 5- l A " floppy disk drive, then interface your high- resolution monitor. But that's not all. Only NRI gives you a top-rated micro with complete training built into the assembly process DIGITAL MULTIMETER Professional test instrument for quick and easy circuit measurements HARD DISK DRIVE 20 megabyte hard disk drive you install internally for greater disk storage capacity and data access speed. PACKARD BELL COMPUTER NEC V40 dual-speed (4.77MHz/8MH«0 CPU, MOK RAM, J60K double-sided floppy disk drive, Your NRI hands-on training continues as you install the powerful 20 megabyte hard disk drive — today's most- wanted computer peripheral — included in your course to dramatically increase your computer's data storage capacity while giving you lightning-quick data access. Having fully assembled your Packard Bell VX88, you take it through a complete series of diag- nostic tests, mastering professional computer servicing techniques as you take command of the full power of the VX88's high-speed V40 microprocessor. In no time at all, you have the confidence and the know-how to work with, troubleshoot, and service every computer on the market today. Indeed, you have what it takes to step into a full-time, LESSONS Qcarcut, illustrated texts buiid your understanding of computers stepbv step. SOFTWARE Including MS-DOS GW-BASIC. word processing, database, and spreadsheet programs. money-making career as an industry technician, even start a computer service business of your own. New voice synthesis training adds an exciting new dimension to your computer skills Now NRI even includes innovative hands-on training in voice syn- thesis, one of today's most exciting and widely applied new develop- ments in computer technology. You now train with and keep a full-featured 8-bit D/A converter that attaches in-line with your computer's parallel printer port. in school, on the job, how to troubleshoot and like NRI MONITOR High-resolution, nonglare, 12" TTL monochrome monitor with tilt and swivel base. TECHNICAL MANUALS You get ' "inside" your Packard Bell computer system with exclusive NRI Training Kit Manuals plus technical specs direct from the manufacturer. DISCOVERY LAB Complete hreadboarding system to let you design and modify circuits, diagnose and repair faults. DIGITAL LOGIC PROBE Gives you first-hand experience analyzing digital circuit operation. one more way NRI gives you the confidence- building experience you need to feel at home with the latest advances in computer technology. Using your D/A converter along with the exclusive text-to-speech software also included, you explore the fascinating technology behind both digitized and synthesized computer speech. You discover how you can use your computer to access and play back a variety of prerecorded sounds . . . you see how to add speech and sound effects to programs written in BASIC, C, Pascal, and others . . . you even learn how to produce high-quality speech directly from your own original printed text. NRI's exclusive new hands-on training in voice synthesis is just No experience needed, NRI builds it in You need no previous experience in computers or electronics to succeed with NRI. You start with the basics, following easy-to-read instructions and diagrams, moving step by step from the fundamentals of elec- tronics to sophisticated computer servicing techniques. With NRI's unique Discovery Learning Method, you're sure to get the kind of practical hands-on experience that will make you fully prepared to take advantage of every opportunity in today's top-growth field of computer service. With NRI, you learn at your own pace in your own home. No classroom pressures, no night school, no need to quit your present job until you're ready to make your move. And all throughout your training, you have the full support of your personal NRI instructor and the NRI technical staff. Your FREE NRI catalog tells more Send today for your free full-color catalog describing every aspect of NRI's innovative computer training, as well as hands-on training in robotics, video/audio servicing, telecommunications, electronic music technology, and other growing high-tech career fields. If the coupon is missing, write to NRI School of Electronics, McGraw-Hill Continuing Education Center, 4401 Connecticut Avenue, NW, Washington, DC 20008. PC/XT and XT are registered trademarks of International Business Machines Corporation School of Electronics McGraw-Hill Continuing Education Center 4401 Connecticut Avenue, NW Washington, DC 2O008 S] CHECK ONE FREE CATALOG ONLY □ Computers and Microprocessors □ Robotics □ TV/Video/Audio Servicing □ Computer Programming HI For career courses approved under GI Bill D check for details □ Security Electronics □ Electronic Music Technology □ Basic Electronics D Telecommunications Name (Please Prim) *■& Address Ciiy /State/Zip Accredited Member, National Home Study Council Ask R'E WRITE TO: ASK RE Radio-Electronics 500-B Bi-County Blvd. Farmingdale, NY 11735 BINARY CODING I've seen lots of information on how numbers are encoded in bin- ary and I've come across IC's that convert one system to the other. What is not clear to me is how binary is used to represent the characters of the alphabet. How is it done and are there any IC's around that can do that? — N. Co- hen, Hagerstown, Maryland You're asking a really basic question, so it seems that you're a bit confused about basic is- sues. There are quite a few books that do a good job of introducing readers to the standards that have been adopted for number systems and how they're used to encode data. Since you already understand how numbers are represented in binary, you won't have any trouble understanding how the same thing is done with alphabetic characters. There's a direct relationship between the decimal representa- tion of numbers and their binary counterparts. You can see that in Table 1. In binary, only two symbols (1 and 0) are used while ten (0 to 9) are used in decimal. The binary symbols are referred to as "bits," and the decimal symbols are re- ferred to as "numbers." CO y o ec H a ID _l HI Q DC 12 TABLE 1 BINARY DECIMAL 0000 0001 1 0010 2 0011 3 0100 4 0101 5 0110 6 0111 7 1000 8 1001 9 and so on Somewhere back in pre-histo- ry, it was decided that eight bits would be referred to as a "byte," and that a different byte would be used to encode each of the characters of the alphabet, the numbers, and the standard punctuation symbols. Each sym- bol was assigned to a unique two-byte value — an upper-case "A" would be represented by the two bytes 0100 0001 {or 65 deci- mal), the number "3" would be given the two bytes 0011 0011 (or 51 decimal), and so on. The stan- dard codes became known as "ASCII" (pronounced "as-key," for /American Standard Code for /nformation /nterchange), and they are still used as the basis of all data transmission and digital technology. Since the major use for the AS- CII standard was initially in send- ing information over teletypes, several places in the two-byte ta- ble were reserved for additional codes to control the teletype ma- chines as well as make sure that information was transmitted without errors. A "Line Feed" be- came a 0000 1010 (or 10 decimal), and a "Carriage Return" was a 0000 1101 (or 13 decimal). You can find a complete ASCII table in most computer manuals or any good book on data trans- mission. What you'll notice is that only half of the table is used. Even (hough the two -byte table has room for 256 entries, only the first 128 are used for the stan- dard symbols and the control codes — the upper half of the standard table is empty. The rea- son for that is that while only seven bits (128 places) were needed to accommodate all the required characters, most digital technology was built around the idea of eight-bit data. When computers started be- coming popular in the late sev- enties, the eighth bit in the two- byte table was used by hardware manufacturers to convey extra information. The Apple comput- er, for example, used the eighth bit to indicate how the character would appear on the screen — normal, inverse, or flashing. Other manufacturers, such as IBM, used the top half of the ta- ble to house an "extended AS- CII" character set. Those include some foreign-language charac- ters, graphics symbols, and other non-standard things that are unique to the IBM character set. One of the things that's proba- bly confusing you is the dif- ference between a character's symbol and it's value. The number 7, for example, has a particular arithmetic value (one more than 6), but the ASCII character set doesn't deal with arithmetic — it's only used to con- vey character symbols, not val- ues. The numerical value of 7 can be represented by using "7," "0111," or even "VII." The sym- bols may be different but they're all being used to represent the same number. Binary-to-decimal number conversion is such a common job that there are several stan- dard IC's designed specifically for that purpose; a 4514, 74154, and other chips will take a binary input and give you a decimal out- put. Converting binary representa- tions of ASCII characters to al- phabetic symbols means using "Character Generators." They Radio /hack Part/ Place )UR 69th YEAR OF BARGAINS FOR BUILDERS! Parts Special-Order Hotline "^==5 No Minimum Order Your Radio Shack store manager can special-order a wide variety of parts and accessories from our warehouse, including vacuum tubes, ICs, microprocessors, phono cartridges and styli, crys- tals, even SAMS Photofacts®. There's no minimum order, no postage or handling charges. Fast delivery to our store near you! New! Battery Hotline Service ■ In addition to our large in-store stock, Radio Shack can now supply almost any currently manufactured battery — even special types. There's no postage or handling charge. Delivery to your nearby Radio Shackl Build it Better with Archer® Tools computer rs-232 connections (1) Nibbling Tool. Chassis holes and car stereo installation made easy I Neatly cuts up up to 18-gauge steel, #64-823 10.95 (2) "Pro" Wire Stripper, Our best! This high-quality tool gives you perfect strips every time on 8 to 22-gauge wires. #64-1919 11.95 (3) 100-Watt Soldering Gun. UL listed AC. #64-2193 10.95 Fig DoscripEion 6a| No Only 1 2 D-Sub 9 Male D-Sub 9 Fem. Metal Hood 278-1537 276-1538 276-1508 .99 1.99 2.19 D-Sub 25 Male D-Sub 25 Fem. Metal Mood 276-1547 276-1546 276-1510 1.49 2.49 2 79 (4) 9-Cond. Double-Shielded Cable. #278-775 '. . Per Foot 59C 25-Cond, Double -Shi elded Ca- ble #278-776 Per Foot 1.19 (5) RS-232 Tester. Connect In line and dual-color LEDs help you pinpoint line problems. D-sub 25. #276-1401 14.95 Temp Module Prewired, use "as-is" for a thermometer or add simple support parts to build a control- ler or alarm With circuit data. LCD display. #277-123, 19.95 More Bargains! (1) BoxfBoard. With 2x3'fe" PC board. #270-291 4.99 (2) SPDT 1A Micro Relay. 12VDC coil. #275-241 1.99 (3) SPST Push On /Push Off Switch. #275-011 1.39 PC-Board Kit 195 Two blank boards, pen. solvent, etch- ant, layout re- sist strips, tank, drill bit and complete instructions, #276-1576 Etch Your Own Boards! Add Action (1) Mini DC Motor. Requires Vh to 3VDC. #273-223 . . 99« (2) Mini Plezo Buzzer. Only 7 mA 12VDC. #273-074 . . 2.99 (3) Jumbo 5000 mcd LED. Big, bright! #276-086 . . . 4.99 solar values r id # m I Factory-Fresh ICs Low As 79* unusual Parts Chime/Alarm (1) Solar Fun Kit, With solar cell, motor and project book. #277-1201 10.95 (2) 2x4 cm Sotar Cell. Top quality! Rated 0.3A, 0.55VDC in full sun. #276-124 . . . 3.95 24 95 Device Cat No Only 741 Op Amp 1458 Dual Op Amp LM324 Quad Op Amp 555 Timer IC 276-007 278-03B 276-1711 278-1723 .79 ,99 .99 1.19 (1) Low-pF Capacitor Kit. Set of 50. #272-806 Set, 2.99 (2) Thermistor. Range is -50 to + 110° C. #271-110 1.99 (3) 1:1 Audio Transformer. Z: 600-900Q. #273-1374 3.59 Mounts On Door Easy to install and has two modes: super - loud alarm or a pleasant > chime to announce guests or customers. Keyboard arming. Battery extra. #49-422 General Ham course 19 95 Radio Shack's General Class FCC License Preparation Package makes it easy to up- grade from novice or technician class. In- cludes sample questions, correct answers and full explanations, two speed-building code cassettes and sturdy binder. #62-2404 Extra -Feature dvm NEW! 79^ Here is everything you'd expect in a quality digital volt-ohmmeter PLUS ca- pacitance and transistor- gain ranges! Easy-to-read 0.5" LC display. Measures AC/DC volts and current, re- sistance, capacitance and transistor gain. With probes and manual. #22-194 Breadboard & Jumpers (1) Deluxe Breadboard. Molded 2Vjx6 1 fe" board is mounted on a 7 x A" steel base with rubber feet. Features 640 plug-in points and three binding posts. #276-169 19.95 (2) NEWI Breadboard Jumper Wire Kit. In- cludes 140 insulated, pre-stripped wires in a snap-shut plastic box. #276-173 ... Set 4.95 Over 1000 items in stock! Binding Posts, Books, Breadboards, Buzzers, Capacitors, Chokes, Clips, Coax, Connectors, Fuses, Hardware, ICs, Jacks, Knobs, Lamps, Mullitesters, PC Boards, Plugs, Rectifiers, Resistors, Switches, Tools, Transformers, Transistors, Wire, Zeners, Morel Prices apply at part ici paling Radio Shack stores and dealers Radio Jhaek The Technology Store' A DIVISION OF TANDY CORPORATION > < CO CO o CIRCLE 78 ON FREE INFORMATION CARD 13 are just memory lC's that have been programmed with the AS- CII character set. They take bin- ary values at their input and present the ASCII equivalent code at their output. Chips like a 4511, or others designed to drive seven-segment LED displays, convert binary data to informa- tion you can use to directly dis- play ASCII characters. Remember that there's a dif- ference between the value of a number and the character used to represent it — one has nothing to do with another. As a matter of fact, that kind of confusion can only come about when you talk about numbers since they're the only members of the ASCII character set that have an abso- lute arithmetic value. The letters, punctuation marks, and control codes that make up the rest of the standard ASCII set may be able to convey lots of meaning, but you can't use them to bal- ance your checkbook. You Have Counted on Us for 15 Years You have counted on OPTOELECTRONICS Hand Held Frequency Counters to be the best quality, to be affordable and reliable. We have been there for you with Frequency Counters that are compact and ultra sensitive. And more and more ol you are counting on us, technicians, engineers, law enforcement officers, private investigators, two-way radio operators, scanner hobbyists, and amateur radio operators, just to name a few. Hand Held Series Frequency Counters and Instruments MODEL 2210 1300H/A 2400H CCA CCB RANGE: FROM 10 Hz 1 Mil? 10 MHz 10 MHz 10 MHz TO 2.2 GHz 1-3 GHz 2.4 GHz 550 MHz 1.8 GHz APPLICATIONS General Purpose Audio-Microwave RF Microwave Security Security PRICE $219 $169 S1S9 S?99 $99 SENSITIVITY 1 KHZ < 5 mv NA NA NA NA 100 MHz < 3 mv < 1 mv < 3 mv < .5 mv < 5 mv 450 MHz < 3 mv < 5 mv < 3 mv < 1 mv < 5 mv 850 MHz < 3 mv < 20 mv < 5 mv NA < 5 mv 1 .3 GHz < 7 mv < 100 mv < 7 mv NA < 10 mv 2.2 GHz < 30 mv NA < 30 mv NA < 30 mv ACCURACY ALL HAVE +/- 1 PPM TCXO TIME BA SE. w o z o DC F o UJ _l UJ 6 5 < 14 All counters have 8 digit red .28" LED displays. Aluminum cabinet is 3.9" H x 3.5" x 1". Internal Ki-Cad bsllflrses provide 2-5 hour portable o Deration with contiguous operation from AC line charge rtpower supply supplied. Model CCB uses a 9 volt alkaline battery. One year parts and tabor guarantee. A lull Line ol probes, antennas, and accessories is available. Orders to U.S. and Canada add b-x id lolal (32 mm, S10 max). Florida residents, add 6% sales lax. COD lee S3. Foreign orders add 15%. MasterCard and VISA accepted. Orders lo U.S. and Canada add 5% to Iota! (S3 mm. $10 max) Florida residents, add 6% sales lax. COD fee S3. Foreran orders add 15%, MaslerCard and VISA accepied OPTOELECTRONICS IMC. 5821 N.E. 14th Avenue • Fort Lauderdale, Florida 33334 1-800-327-5912 FL (305) 771-2050 FAX {305) 771-2052 2N2222 AND GATE I learned the basics of digital electronics in the navy, and have even made basic gates from dis- creet components. At the moment, I'm trying to hook up a third brake light that will light up when the other two light. I need an AND gate to do the job but I'm not sure how to build one with individual components. I haven't experi- mented yet, but I don't think I can do the job with a pair of 2N2222's and some resistors. Do you have any ideas? — V. Sandoval, San Di- ego, California I have several ideas. I under- stand that you want to light a third brake light, but it seems to me you're making the job un- necessarily complicated. While there's no electronic reason why you can't build an and gate out of discrete hardware, it seems like a lot of extra work. Of course, there's no rule about that sort of thing and one nice thing about re- inventing the wheel is that you really learn how the wheel works. One way to do it is shown in Fig. 1. The transistors are operating as simple switches, and when both of your existing tail lights are on, you'll wind up with voltage across the third tail light. I seriously doubt that you can get by with a TO 'BULB £££. TEXT 6 6 FIG. 1 pair of 2N2222's, because most au- tomotive bulbs draw much more current than can be handled by a small-signal NPN. You can either use beefier transistors or, if you want to complicate your life even further, you can have the tran- sistors drive a relay with contacts rated for a high enough current. The relay isn't such a bad idea since driving the bulb directly with the transistors will leave you with a working voltage of some 1.2 volts less than battery voltage. Re* member that you're going to lose about 0.6 volts through each of the transistors. If you use a relay, you'll be able to power the third bulb directly off the battery. continued on page 99 CIRCLE 147 ON FREE INFORMATION CARD TABl The Electronics Book Source oh-uter TtOMOUTS tUWOQGK NEW Computer Technician's Handbook— 3rd. Ed. by A. Margolis. Repair components and systems, perform routine maintenance, and diagnose defective equipment with this completely revised edition of the popular bestseller on microcom- puters. 590 pp., 409 illus. #3279H, S3 4. 9 5 Pass the Associate and Journeyman Exams with Flying Colors and Save $10 on the Set! The CET Exam Book— 2nd Ed. by ft Crow and D. Glass The CET Study Guide— 2nd Ed. by S. Wilson Two-Volume Set (#5300C) Yours for S35.90 (regularly $45.90) Save 15% and Build, Build, Buiid! 49 Battery-Powered One-IC Projects by D.T. Horn. 163 pp., 153 illus. 49 Battery-Powered Two-IC Projects by D.T. Horn. 126 pp., 125 uius. Two-Volume Set (#5381 C) Yours lor S31.95! (regularly S37.90) NEW SAVE $15 International Encyclopedia of Integrated Circuits by s. Gibilisco. Take advantage of the latest foreign and domestic IC technologies. 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Get the edge you need to pass Ihis important lestl 259 pp., 125111ns. #3118H, S23.95 How to Draw Schematics and Design Circuit Boards with Your IBM PC byS. Sokolowski. Per- form computer-aided engineering for a traction of the cost! 187 pp., 113 illus. #3034H, S19.95 Build the Ultimate in High-Tech Projects —Save 20% on the Set! Experiments in CMOS Technology 304 pp. 249 illus.. #3062H, S24.95 Experiments in Gallium Arsenide Technology 256 pp., 177 illus.. C3052H, S24.95 Experiments with EPROMS 240 pp., 2(8 illus.. ■2962H. S24.95 Three-Volume Set (S5356C) Only SS9.88 (regularly S74.85) BESTSELLERS i ELECTRONIC . CIRCUITS Save Over SI on the Complete Circuit Library! Order Volumes 1 & 2 for Only $49,95 (#5376C) (regularly S59.90) The Encyclopedia of Electronic Circuits— Vol. 1 by R. Graf. Get hundreds of dilierent circuits in one handy guide! ?B8pp., 1762 illus No, I93BP, S29.9S The Encyclopedia of Electronic Circuits— Vol. 2 by R Graf. 700 1 circuits you'll use again and again! 744 pp., 728 llfus. #3138P, $29.95 Troubleshooting and Repairing VCRs by G. McComb. Save money or make money doing VCR repairs! 336 pp., 200 illus. #2960H, S27.95 TO ORDER, Call Toll Free: 1-800-822-8158 (in PA and AK call 1-717-794-2191) or mail coupon to: TAB BOOKS Inc.. Blue Ridge Summit, PA 17294-0840 Please send me the book(s) below. No Price Nn Price No. Price. PA. NY. and ME residents add applicable sales tax (Outside the US add 55.00 shipping & handling > TOTAL Check or money order enclosed (made payaole to TAB BOOKS Inc.) Charge my VISA ~ MasterCard American Express . Exp Acct, No. Signature Name Address _ City/Stale/Zip Offer good until March 1, 1990 Satisfaction Guaranteed— If you are nol satisfied, return the books for a complete refund. reiso CIRCLE 146 ON FREE INFORMATION CARD > z c > < CD (D O 15 Letters zsrrsAs lHAQ/O - EL ec TA OWCS SOQ-a &/• COUNTY SOULS YARD rAXMINGMLE, M Y //7SS HELPFUL HINTS 1 would like to offer some com- ments and suggestions con- cerning some recent items in Radio-Electronics. First, a better way to control a pump than that presented in Ask R-E (November 1989) is to use the LM 1830 fluid-detector IC. Its ad- vantages over a simple transistor circuit are fully described in the National Semiconductor Linear Databook, along with typical cir- cuits, etc. The most important of those advantages is that the LM 1830 uses a very low-level AC signal (typically 7 kHz) for the sensing function, which eliminates the "plating" that can and does occur overa long period with DC signals. It can control a low-current relay directly, a larger relay via an inter- mediate transistor, and a triac or quadrac via simple intermediate circuitry. I have used that IC and associated components to control a pump that removes water from an area subject to flooding during heavy rains, and as a much more reliable alternative to the high- priced (but poor quality) switches sold to control 12-volt bilge pumps in boats. Concerning the infrared-con- trolled A/B switch (Radio-Elec- tronics, October 1988), relay switching is enhanced by using a double-pofe-double-throw RF re- lay that connects the input that is not being used to a 75-ohtn load resistor. That both improves isola- tion and avoids any problems that £ a mismatch could cause. 5 The Radio Shack 276-137 detec- ts: tor module ($3.49) is convenient to o use for IR controllers. It includes j an IR phototranststor, amplifier, fil- £ ter, and detector in a small PC- 5 mountable package. The IR source (r should be turned on and off at a 40-kHz rate. That 40-kHz signal should then be pulsed at an audio rate. The output of the Radio Shack detector is the audio rate. It is detected by one or more 567 tone-detector chips. The transmit- ter is, conveniently, a 556 dual timer. One half of it operates at 40 kHz to drive the IR emmiter diode (or, preferably, two diodes in se- ries). The other half operates at the audio rate and pulses the 40-kHz oscillator via its reset pin. I built a circuit that allows me to select one of three sources (A, B, or C) using two RF relays and small SCR's for latching. Instead of sim- ply toggling back and forth be- tween signals, the receiver has three 567 tone decoders and the logic to select the desired source corresponding to the tone sent by the IR transmitter. The modulation frequency in the hand-held trans- mitter is selected by pressing one of three buttons. All three buttons turn on both halves of the 567; two of them also control diode switch- es to change the audio-modula- tion frequency. Simple diode logic allows the use of single-pole push- buttons. The audio-modulating frequencies are about 700, 1000, and 1300 Hz. When a button is pressed, the one desired is se- lected by means of diode switches that change the capacitor value in the half of the 556 used in the transmitter to generate the audio tone. The frequencies are not accurately adjusted; the 567 tone decoders are tuned to whatever the modulating frequencies hap- pen to be with the capacitors used in the transmitter. L.D. THOMAS Georgetown, DE NTSC/PAL VCR CONVERSIONS I read a letter in a recent issue of Radio-Electronics that discussed the possibility of converting PAL VCR tapes to NTSC. That is a major dilemma for servicemen stationed in Europe. Here we sit with Amer- ican TV's and VCR's, unable to watch EURO-TV or rent PAL VCR tapes. To do so we must purchase another TV and VCR in PAL format. I have searched here in England for a converter device, as the EURO-TV presents American TV shows. There is such a "black box" that has extras required for profes- sional broadcasting (color and sound mixing, enhancers, etc.) — but it costs about $2500. I would like to find one that just converts either the RF signal or the video and audio signals between PAL and NTSC. 1 have also found a Motorola chip, the MC1377P, that converts a video RGB signal to a switchable NTSC/PAL composite signal. I have tried to find a way, but 1 can't find the solution to make it work. Could you possibly run an arti- cle on the merits or disadvantages of doing that, and maybe a design for a do-it-yourself kit? CHARLES MAY, TSgt USAF RAF Alcon bury, UK AUTOMATIC TEST EQUIPMENT I appreciate your publishing my article, "Automatic Test Equip- ment," in the October 1989 issue of Radio-Electronics. However, some changes made during edit- ing might give readers some er- roneous impressions. A computer and a controller are mentioned, on page 61, as being separate parts of an ATE. Actually, they are one and the same, as stated in my manuscript. The com- puter controls things in the ATE. Figure 1 in the article is mis- labeled, giving the impression that the ATE is to the bottom of the 16 dashed lines. The ATE is actually the portion that is shown above the dashed lines. The portion be- low the dashed lines and the two interface rectangles is the outside world. Finally, the next-to-last para- graph on page 62 states that func- tional testers test signals at UUT inputs. In reality, they apply test signals at UUT inputs, and then check the response at the UUT output. Although the differences are minimal, I felt you and your read- ers would want to know about them. ALLAN C. STOVER CHEMICAL CONFUSION 1 appreciate Robert Grossblall's series of articles on printed circuit- board construction (Designer's Notebook, October— December 1989), and I'd like to pass on some information that might benefit other readers. The Kodak chemi- cals described in the November 1989 column are no longer carried by Kodak. Apparently Kodak sold the division that produces those chemicals to Union Carbide, who placed them in their own KTI divi- sion. KTI sells only through dis- tributors and only one of those distributors sells the chemicals in small quantities. The bottom line is that a compa- ny in Pennsylvania called PCE (why do chemical companies always use initials?) will sell to individu- als. Their phone number is 215-296-8585. They accept Amer- ican Express or ship UPS-COD. The prices are roughly $61.00 for one quart of photo resist, $30.00 for the developer, and $7.00 for the booklet. The catalog numbers in the article haven't changed. PCE carries a wide variety of chemicals, so it is important to have the cata- log numbers in hand when placing an order. Thanks for your efforts to keep the hobbyist informed. I look for- ward to finally making quality printed-circuit boards. Keep up the good work, DR. BARRY C. MEARS Florissant, MO FAX-MATE FACTS It has come to our attention that there are a few errors concerning the Fax-Mate article (Radio-Elec- tronics, October, 1989), In the schematic of Fig. 2, R3 should be moved into the feedback loop of IC1, and the primary (right side) and secondary (left side) of T1 were not labelled. In the parts- placement diagram of Fig. 3, the labels of the primary and second- ary sides of T1 should be trans- posed. That's because T1 is actually being used in reverse; a voltage input to the secondary is stepped up and output at the primary. — Editor IR REMOTE EXTENDER If you built the IR remote-con- trol extender {Radio-Electronics, May 1989), and noticed noise or snow on your TV screen when using the device, a 0.1-julF ceramic- disc capacitor connected between the intersection of D1 and R6 and ground will cure the problem. Other problems with the unit's op- eration may be caused by a poorly regulated +9-volt DC supply (which is often true with many of the inexpensive plug-in power adapters). The addition of a 9-volt Zener diode across the +9-volts (cathode to positive, anode to negative) will eliminate the pos- sibility of any power-supply re- lated problems. — Editor DIG! -COMPASS Certain errors made their way into the Digi-Compass story (Ra- dio-Electronics, November, 1989). In the schematic of Fig. 3, the la- bels V cc and V DD should be trans- posed, and V OD should be 6.8 volts instead of 6.5. Also, the two voltages are outputs, and should therefore have open circles in- stead of arrows. The labels for pins 2 and 3 of IC3 should also be trans- posed; pin 2 is inp and should be connected to IC2pin 7, and pin 3 is ref- and should be connected to IC2 pin 8. On page 51, in the right- hand column toward the bottom of the page, the text states that "the number of data acquisition averages can be changed by push- ing the ',,' keys." It should have read "by pushing the ">" and "<" keys." And, last, on page 82, "TEX- TCOMPLPTnlO" should contain spaces between arguments; it should be written as "TEXTCOMP LPTn 10."— Editor R-E CIRCLE 108 ON FREE INFORMATION CARD Be an FCC LICENSED ELECTRONIC TECHNICIAN! experience needed! No costly School. No commuting to class. The Original Home-Study course pre- pares you for the "FCC Commercial Radio- telephone License". This valuable license is your "ticket" to thousands of exciting jobs in Communications, Radio-TV, Micro- wave. Computers, Radar, Avionics and more! You don't need a college degree to qualify, but you do need an FCC License. No Need to Quit Your Job or Go To School This proven course is easy, fast and low cost! GUARANTEED PASS— You get your FCC License or money refunded. Send for FREE facts now. MAIL COUPON TODAY! commariD productioms FCC LICENSE TRAINING, Dept. 90 P.O. Box 2824, San Francisco, CA 94126 Please rush FREE details Immediately! name ADDRESS STATE ZIP I > i =9 ■ CO 1 8 .J 17 BEST FOR LO u z o c I- o LLI o D < 18 Tek's new 50 MHz 2211 gives you more measurement power for the money than any scope in its class. If you want the performance of an expensive digital scope, but not the cost, our new 2211 is the perfect solution. It represents Tek know-how and quality at its affordable best. It combines powerful 20 MS/s digital sampling with the familiar operation of an analog scope, in digital storage mode you can capture and display single-shot events, see what happened before a trigger event, or compare newly-acquired signals to a stored waveform. And if you need to analyze fast or complex signals in real time, simply switch to analog mode with the push of a button. Productivity-enhancing features are in abundant supply. For instance, all mea- surements and front-panel scale factors appear on the CRT Waveform cursors automati- cally calculate time and voltage. A 4K record length and X50 magnification give you excellent timing resolution, plus analog-quality displays. And trigger levels can be read directly on the screen. Ctfyritfl © TetoiwiEt. Inc 198) 'fflos SJbjea 10 aeng ana olid in(J S on^ EducSiora! discounts aaKite on foquesi EOB-0C6 CIRCLE 92 ON FREE INFORMATION CARD W-COST TEST There's even a standard hardcopy interlace that lets you connect the 2211 to Epson printers or HPGL- compatible plotters, such as the Tek HC100, for convenient automatic 4-color documentation. Of course, the true indication of why the 2211 is "best for low-cost test" is price: it's only $2495. A sum that includes Tek's remarkable 3-year warranty on all parts and labor — even the CRT Three value-packed companions starting at $695. Model Number 2211 2201 2225 2205 Bandwidth 50 MHz 20 MHz 50 MHz 20 MHz Storage Bandwidth 1MHi 1MHz N/A N/A Sample Rate 20 MS/S/Ctl ID MS/S/Ch N/A N/A Vert. Sensitivity 500 (iWntV 5 mV/div 500 fiV/div 5 raV/drV Cursors/Readout >fes No No No Hardcopy Interface Ifes Oplian No No Record Length 4K/ch 2tVch N/A N/A Vertical Resolution 8 bit Soil N/A N/A Price* $2495 $1495 11095 $695 For low-cost testing from 20 to 50 MHz, Tek has the best line-up in the business. There's the 50 MHz 2225, which offers superb vertical sensitivity, delay, and horizontal magnification up to X50 for only $1095. The 20 MHz, 10 MS/s 2201 is an economical introduction to digital storage at $1495. And for reliable, ultra low-cost analog measurement, get the 20 MHz 2205 for an incredible $695, It's easy to get the best. To order your low-cost Tek oscilloscope or get more information, contact your local Tek representative. Or call Tek direct at: Is? 1-800-426-2200 Ttektronix COMMITTED TO EXCELLENCE > z c > 3) -< 21 o Equipment Reports Elenco Micro-Master 8000 Computer System Course Learn computer theory, construction, and programming with hands- on experience. CIRCLE 45 ON FREE INFORMATION CARD THERE IS, PERHAPS, NO BETTER WAY TO learn the fundamental concepts of computer operation than by build- ing and programming a computer. The best way to accomplish that is through some sort of structured course, such as the Micro-Master 8000 microprocessor training sys- tem from Elenco Electronics, Inc. (150 West Carpenter Avenue, Wheeling, IL 60090). The MM-8000 offers a 14-lesson course that covers the fundamen- tals of number systems through the writing of practical machine- language programs. The heart of the system is the Intel 8085 8-bit microprocessor. While the 8085 is not the latest and greatest micro- processor, it is a good choice to demonstrate important concepts. While we examined an as- sembled version of the trainer, the course is most instructive in its kit form, wherein the MM-8000 PC board is built step by step as each z lesson progresses, and experi- a: ments demonstrate the operation o of the various subsystems. o < 22 Step by step The first lesson in the course de- scribes the basics of number systems. Specific attention is paid to the decimal number system with which we are all familiar, and the hexadecimal and binary sys- tems used by computers. The sec- ond lesson introduces the con- cepts of computer data, and data buses, and guides the student through the installation of data- bus indicators and switches. Intel's 8156 static RAM IC with I/O ports and timer is the subject of lessons 3 through 5. Various on- board switches are used to man- ually write to and read from the RAM. Once that concept is dem- onstrated, 7-segment LED displays are added, and the I/O ports of the 8156 are used to control the dis- play. The timer portion of the 8156 is also programmed and run. In lesson 6, a 2816 monitor ROM is added to the setup, and the dif- ferences between ROM and RAM are demonstrated. The 8085 microprocessor is the topic of lessons 7 and 8. Items dis- cussed include the chip's internal registers, flags, and interrupts. The microprocessor's memory- read and -write cycles are de- scribed with the help of timing di- agrams, and the function of each pin is explained. Finally the com- plete instruction set of the 8085 is detailed. Lessons 9 through 13 describe what the monitor program is, and how it fits in the memory-alloca- tion scheme of the MM-8000. The monitor is loaded into a 2816 E 2 PROM one program at a time. The main components include the initialization, display, keyboard- scan, and function-key sections. In the final lesson, the complete system is used to execute an exter- nal program, adding two numbers and displaying the result. That cer- tainly doesn't sound like any great feat to anyone who has ever oper- ated a pocket calculator — but then again, most people have no con- cept of how a calculator performs its magic. The student who completes the MM-8000 course, however, will understand the basic operation of the 8085 microprocessors, and of microprocessors in general. He will also have an understanding of the basic subsystems of micro- computers, and how they are pro- grammed. While a dedicated student might find the MM-8000 ideal as a self-training course, we feel it would be more useful in a school laboratory course, where a teach- er and auxiliary texts could aug- ment the course manual. We feel that the manual needs some sup- plementation because it leaves out what we think is important infor- mation. For example, the 2816 is never referenced as an E 2 PROM, and the functions of some of the other IC's are not well detailed. Granted, those points may not be considered important in a micro- processor course, but they are im- portant nonetheless. The Micro-Master 8000 kit costs $129. We recommend it as an ex- cellent introduction to micro- processors. R-E Hameg HM8028 Spectrum Analyzer Module Convert any oscilloscope to a 500- MHz spectrum analyzer IF you're in the market for a spec- trum analyzer but need to keep costs to a minimum, you might find that you can make substantial savings by converting your os- cilloscope to do the job. One de- vice that makes it easy to do just that is the HM8028 spectrum ana- lyzer module from Hameg (88-90 Harbor Road, Port Washington, NY 11050). The HM8028 is designed as part of Hameg's HM8000 modular sys- tem series. It can be used, how- ever, with any oscilloscope that offers an X-V operating mode. The heart of the HM8000 modular sys- CIRCLE 46 ON FREE INFORMATION CARD tern is the HM8001 mainframe. The mainframe accommodates up to two plug-in modules, and supplies them with power and a signal bus. The HM8028 spectrum-analyzer module offers a frequency range of 500 kHz-500 MHz. Its front pan- el features a clean layout, which is dominated by a 3-digit LED display of the center frequency. A ten-turn potentiometer is used to adjust the frequency. The scan width control, which is used to adjust how much of the spectrum you want to observe around the center frequency, is an 11-posttion rotary switch. It is adjustable from 50 kHz/div to 50 MHz/div, and a zero- scan position is also available. Other front-panel controls in- clude an RF gain potentiometer, a 4-pushbutton input attenuator, and bandwidth and video-filter switches. Input to the analyzer is provided by a 50-ohm BNC connector. A twin BNC connector, along with a special cable, provides output to the X and Y amplifiers of an os- cilloscope. Setting up the spectrum ana- lyzer is quite easy. The analyzer's output is connected to the X and Y inputs of the scope, and the scope is set to its X-Y mode. Both scope channels are set to a sensitivity of 5 volts/div, the input-coupling switches are setto ground, and the beam is adjusted so that it is cen- tered on the graticule. When the scope's input coupling is set to DC, a trace will appear across the bottom of the screen. Adjustment of two trimmers on the analyzer module is required to match the output voltages of the analyzer to the scope being used. When that's With Just One Probe Connection, You Can Confidently Analyze Any Waveform To 100 MHz, 10 Times Faster, 10 Times More Accurately f Absolutely Error Free, Guaranteed — Or Your Money Back! SC61 Waveform Analyzer ™ Patented $3295 There are other digital readout oscilloscopes, but none of them completely eliminate graticule counting and calculations like the SC61 Waveform Analyzer. The innovative, time-saving AUTO-TRACKING™ digital readout automatically gives you every waveform parameter you need for fast troubleshooting. The SC61 Waveform Analyzer is a triple patented high performance scope that provides you with a digital LCD read-out of all key waveform parameters (DC volts, peak-to-peak volts, and frequency) at the push of a button , and all with one probe connection . Other time-saving features include exclusive ECL sync circuits that allow you to lock quickly onto waveforms up to 100 MHz. Plus, with 3000 volts of input protection, you never have to worry about an expensive front end repair job. Call 1 -800-SENCORE to find out more about what the SCBt can do for your service business. In Canada call 1-800-B51-8866. 3200 Sencore Drive, Sioux Falls, SD 57107 100% American Made 2 C > < SO o CIRCLE 155 ON FREE INFORMATION CARD EARN YOUR DEGREE THROUGH HOME STUDY Our Mew and Highly Effective Advanced-Place- merit Program for experienced Electronic Tech- nicians grants credit for previous Schooling and Professional Experience, and can greatly re- duce the time required to complete Program and reach graduation. No residence schooling re- quired for qualified Electronic Technicians. Through this Special Program you can pull all of the loose ends of your electronics background together and earn your B.S.E.E. Degree. Up- grade your status and pay to the Engineering Level. Advance Rapidly! Many finish In 12 months or less, Students and graduates in aJI 50 States and throughout the World. Established Over 40 Years f Write for free Descriptive Lit- erature. COOK'S INSTITUTE OF ELECTRONICS ENGINEERING rfS -< to ID O 25 New Products tn o z o cc h- o ui < NOISE-CANCELING HEAD- SETS. The aviation headsets tested by Dick Rutan and Jeana Yeager on their a round -the- wo rid Voyager flight, are now directly avail- able from Bose. Stemming from Dr. Amar C. Bose's frustration with passenger headsets on a commercial flight in 1978 (the incessant engine noise interfered with listening pleasure), and the direct result of ten years of R&D, in part with the U.S. Air Force, the Bose Aviation Headset features patented electronic circuit- ry that cancels unwanted noise while allowing desir- ed communications to be heard. The headset is an inte- grated system that com- bines patented physical and electronic noise-attenua- tion systems and offers two major improvements over conventional headsets. First, the "Clear Comfort" cushions on the earcup, which conform precisely to the contours of the head, seal out noise without un- comfortably high force. Second, the headset's elec- tronic circuitry actively can- cels much of the noise. A sound-pressure servo (feedback) system uses mi- crophones in the earcups to monitor the sound at the user's ear; that measured sound is compared with the CIRCLE 25 ON FREE INFORMATION CARD sound the user wants to hear — for example, radio communications or, if no signal is provided, silence. The difference between the existing and the desired sound is then "processed" to create a correction signal that is opposite to the un- wanted noise and, when re- produced by the speaker in the earcup, cancels the noise. The process of mea- suring, creating a correction signal, and usingittocancel noise is rapid and continu- ous, allowing the Aviation Headsets to react to any dy- namically changing noise source. The Aviation Headsets of- fer pilots, particularly in propeller-driven aircraft and helicopters, improved communications, reduction in fatigue, and the preven- tion of permanent hearing loss from ambient noise. Similar headsets would be effective in police, fire, and emergency vehicles, where radio communications must be heard over the sirens. The Aviation Headsets cost $965.00 each, and are being marketed directly through a toll-free number: 800-242-9008.— Bose Corpo- ration, The Mountain, Fra- mingham, MA 01701. PROGRAMMABLE POWER SUPPLIES. CPIB capability is built into every model in Beckman's PPS Series of sys- tem DC-power supplies, eliminating the time-con- suming process of choosing GPIBas an option, installing it, and getting it running. The series includes a 30-volt DC/3.5-A, 40-volts DG7.5- A, 60-volts DC/I0.O-A, and CIRCLE 26 ON FREE INFORMATION CARD 60-volts DO17.0-A models. Each offers full-rated power from 100 to 1000 watts, re- mote sensing to compen- sate for system wiring loss to the load, and a back-lit LCD with adjustable con- trast and illumination. The power supplies feature mul- tiple operating modes, such as delta V, delta T, and man- ual for increased system flexibility. An internal volt- meter and ammeter on each model eliminates the need for an external digital multi- meter, reduces overall sys- tem component costs, and can feed back information via the GPIB, Each unit also offers an automatic pro- grammable timer mode that allows the user to program up to 200 voltage/current- limit settings and 200 time intervals (one-second mini- mum/ten-hour maximum). The PPS Series of pro- grammable power supplies start at $995.00.— Beckman Industrial Corporation, In- strumentation Products Di- vision, 550 South Harbor Boulevard, La Habra, CA 90631. HIGH-SPEED COMPARA- TOR. Combining a variety of features that simplify analog circuit design, the AD790 from Analog Devices con- sumes less than one-third the power of other units in its class. It has a maximum 50-ns propagation delay when operated from a sin- gle + 5-voltorduat ±15-volt supplies. With single-sup- ply operation, power dis- sipation is a maximum 60 mW. It can handle ground- referenced signals, and of- fers a wide input-signal range, on-board latch, TTL and CMOS logic output, and 500-jj.V input-hysteresis voltage. The AD790 is the first comparator that is manufac- tured with Analog Device's high-speed Complemen- tary Bipolar (CB) process. By incorporating CB tran- sistors in the IC design, the comparator can accommo- date rail-to-rail input signals and deliver symmetrical output swings. In single- supply operation, the input signal can range from +5 26 CIRCLE 27 ON FREE INFORMATION CARD volts to ground, permitting wide dynamic range data- acquisition in + 5-volt logic systems. Built-in 500-|xV hysteresis eliminates un- desirable oscillations when handling fast pulses or slow low-level signals. The com- parator's output also mini- mizes current spikes, an- other source of oscillation in many voltage compara- tors. The TTL- and CMOS-com- patible output simplifies connection to digital logic. An on-chip latch can be strobed to retain output data, making the AD/90 useful in building high- speed discrete analog-to- digital converters. The out- put voltage is highly sym- metrical between V loclc and ground, ensuring high accuracy when positive- and negative-slewing input sig- nals cross the threshold level. The AD790 is available in an 8-pin plastic or ceramic DIP and is specified for op- eration over the 0° to +70°, -40° to +85°, and -55° to +125° operating tempera- ture ranges. Two perfor- mance grades are available, with maximum offset volt- age of either 1 mV or 250 |j.V. Maximum common-mode voltage is from +V S to —2 volts; the allowable input signal range is ±V S . The AD790 comparator ranges in price from $2.50 for the JN grade to $7.95 for the SQ version, in lots of 100. — Analog Devices, Liter- ature Center, 70 Shawmut Road, Canton, MA 02021. 100-MHz OSCILLOSCOPE. Three different signals can be observed at two time- base settings on B&K-PRECI- SION's model 2190 os- cilloscope with iriple input, six-trace operation. The high-performance scope provides excellent high-fre- quency triggering, even on signals well beyond its rated bandwidth. The 2190 also feat u res 1-mV-per-di vis ion vertical sensitivity, V-mode for viewing two signals that are unrelated in frequency, dual time base, alternate sweep function, a 20-MHz bandwidth limiter, and vid- eo-sync separators. CIRCLE 28 ON FREE INFORMATION CARD The 100-MHz scope offers users a choice of 23 cali- brated sweep-time ranges from 2 ns to 50 ns per divi- sion on the main time base and 20 calibrated ranges on the delayed-sweep time base. Each sweep time range is fully adjustable be- tween calibrated ranges. A x10 magnifier, which allows closer examination of wave- forms while maintaining display calibration, is also provided. In delayed-sweep operation, the delayed sig- nal can be viewed as a sec- ond trace or superimposed on the non-delayed signal. The 2190 offers front-pan- el x-y operation, TTL-com- patible z-axis input, signal- delay line, single-sweep op- eration, and channel-1 out- put on the rear panel for driving a frequency counter or other instruments. It comes with two 10:1 probes, a user manual, and sche- matic diagram. The model 2790 100-MHz oscilloscope has a sug- gested retail price of $1645.00. — B&K-PRECI- 5ION, Maxtec International Corp., 6470 West Cortland Street, Chicago, IL 60635. ANALOG INPUT MODULE. A module designed for use with the Apple Macintosh Plus, SE, and II computers, Get A Complete Course In ELECTRONIC ENGINEERING 8 volumes, over 2000 pages, including all necessary math and physics. 29 examinations to help you gauge your personal pro- gress. A truly great learning experience. Prepare now to take advan- tage of the growing demand for people able to work at the engin- eering level. Ask for our brochure giving complete details of content. Use your free information card num- ber, or write us directly. $99.95, Postage Included. Satisfaction guaranteed or money refunded. -\ AAAy V Banner Technical Books, Inc. 1203 Grant Ave. Rockford, IL 61103 MORE THAN LOGIC a: 221 286 SupersPort Laptop by Heathkit Your logical source for quality computer and elec- tronic product needs, the FREE Heathkit Catalog is your key to a fun and exciting hobby. The Heathkit Catalog contains powerful kit laptop and desktop computers, test instruments, weather equipment, and home theater components, plus self-study electronics courses. Order your FREE Heathkit Catalog today! It's the logical thing to do! 1-800-44-HEATH (1-800-444-3284) Send to: Heath Company, Dept. 020-854 Benton Harbnr, Michigan 49022 Name Address CJtL CIRCLE 67 ON FREE INFORMATION CARD Lf State _Zjb_ A subsidiary of Zenith Electronics Corporation CIRCLE 86 ON FREE INFORMATION CARD C > CO CO o 27 R-E Engineering Admart 6805 MICROCOMPUTER DEVELOPMENT SYSTEM The MCPM-1 system allows the ISM PC and compatibles to be used as a complete development system for the Motorola MC6S705P3. P5. U3. U5. R3 and P.5 single chip microcomputers. The system inelurtes a cioss assembler program, a si mutator/ debugoer program and a programming board that connects to a serial port. Price— $449 00 VISA and MASTERCARD accepted. ' TM£ £HC!»ltSS ' CBLUBOStTttt. ItC. RR#3,BOK8C Barton , Ve rmo nt 5 82 2 Phone (802) 525-3458 FAX (802) 525-3451 Rates: Ads are 2W x 2 7 A". One insertion $950. Six insertions S925. each Twelve rtions 5895. each. Closing date same as regular rate card. Send order with ittance to Engineering Admart, Radio Electronics Magazine, 500-8 Bi-County Farmingdale, NY 11735. Direct telephone inquiries to Arline Fishman, area code-516-293-3000. Only W0% Engineering arfs are accepted for this Admart. FCC LICENSE PREPARATION The FCC has revised and updated the commercial license exam. The NEW EXAM covers updated marine and aviation rules and regulations, transistor and digital circuitry. THE GENERAL RADIOTELEPHONE OPERATOR LICENSE - STUDY GUIDE contains vital information, VIDEO SEMINAR KITS ARE NOW AVAILABLE. WPT PUBLICATION 979 Young Street, Suite A Wood bum, Oregon 97071 Phonft (503)981-5159 UtDI Projects MIDI PROJECTS BP182 — MIDI interfacing enables any so equipped instruments, regardless of the manufacturer, to Pe easily connected to- gether and used as a system with easy com- puter control of these music systems. Combine a computer and some MIDI instru- ments and you can have what is virtually a programmable orchestra. To get your copy send S6.95 plus $1.25 farshipping in the U.S. to Electronic Technology Today Inc., P.O. Box 240, Massanequa Park, NY 11762-0240. CIRCLE 157 ON FREE INFORMATION CARD CIRCLE 144 ON FREE INFORMATION CARD O o LU LU o < rr MetraByte's SCSI-8AIN per- forms real-time, high- speed, high-resolution, analog input tasks. The eight-channel, 12-bit analog converter is accurate to within 0.02%, with a con- version time of 14(j.s. With 12-bit resolution, the least- significant-bit value is 4.88 mV in the ±T0-volt range. An instrumentation ampli- fier provides gains of 1, 10, 100, 200, or 500 correspond- ing to signal spans of ±10 volt, ±1 volt, ±0.1 volt, ±0.05 volt, and ±0.02 volt, respectively. The gain of the instrumentation amplifier is selected by a front-panel DIP switch. CIRCLE 29 ON FREE INFORMATION CARD Data is transferred to or from the SCSI-8AIN one byte at a time at a maximum rate of 57.6 kilobytes per second and support sample rates of up to 28,800 samples per second. One waveform can be digitized at 28,000 samples per second, and eight waveforms can be dig- itized at 3,600 samples per second. Those rates sup- port up to 8 analog input channels simultaneously, making it capable of provid- ing oscilloscope, chart-re- corder, and spectrum-ana- lyzer emulations. A master clock synchronizes all SCSI-8AIN analog-convert- er activity, so that state infor- mation can be obtained at fixed intervals from multiple channels. The included software drivers allow the module to be controlled by a variety of software packages that run on Macintosh computers, including seven high-level programming languages and five menu-driven ap- plication programs. The SCSI-8AIN communicates via the 5CIA (Small Computer System /nter- face) port located on the back of the Macintosh com- puter. That bus accepts as many as six peripherals to be placed in daisy-chain network. Custom config- urations are very easy to de- velop for such applications as digital signal processing, signal averaging, chroma- tography, spectroscopy, and more. The module comes with a peripheral unit; calibration, test, and I/O software; one SCSI cable; a 117-volt AC desk-top power trans- former; and also comes with hardware and software manuals. The SCSI-8AIN 8-channel, 12-bit analog input module is available for $790.00 and the SCSI-TERM termination device costs $50.00. — Met ra Byte Corp., 440 Myles Stand ish Blvd., Taunton, MA 02780. FUNCTION GENERATOR. Its unique front-pane! de- sign coupled with eight dif- ferent waveforms, seven modulation modes, and op- tional arbttrary-waveform- generation capability make Fluke's PM5138 10-MHz function generator versatile and easy to use. Instead of the array of rotary switches, knobs, and dials usually found on function gener- ators, the PM 5738 has a large, backlit multifunction LCD and five pairs of keys for selecting the required parameter. The frequency, AC voltage, DC offset, and other numerically program- mable parameters are set by pressing the appropriate key and adjusting the unit's one rotary knob until the correct reading appears on the screen. The required waveform and modulation CIRCLE 30 ON FREE INFORMATION CARD modes are selected from a menu. The function generator also offers Arbitrary Waveform Generation (AWG), which is usually found only on specialized arbitrary generators with few waveform and modula- tion modes. Included with the GPIB/IEEE-488 interface option, AWG features a 20 Mega-points/second sam- pling rate, 1024-point hori- zontal resolution, and 1024- point vertical resolution. Waveforms can be pro- grammed over the GPIB ei- ther from a computer or directly from a digital stor- age oscilloscope. The PM 5138 function generator has a suggested list price of $3590.00, or $3990.00 for the model with the factory-installed arbi- trary waveform generation option. — John Fluke Mfg. Co., Inc., P.O. Box C-9090, Everett, WA 98206; 800-443-5853, ext. 77. 28 EXPAND YOUR CAREER HORIZONS.., START WITH CIE. Microprocessor Technology. Satellite Communications. Robotics. Wherever you want to go in electronics... start first with CIE. Why CIE? Because we're the leader in teaching electronics through independent study. Consider this. We teach over 25,000 students from all over the United States and in over 70 foreign countries. And we've been doing it for over 50 years, helping thousands of men and women get started in electronics careers. We offer flexible training to meet your needs. You can start at the beginner level or, if you already know something about electronics, you may want to start at a higher level. But wherever you start, you can go as far as you like. You can even earn your Associate in Applied Science Degree in Electronics. Let us get you started today. Just call toll-free 1-800-321-2155 (In Ohio, 1-800-362-2105) or mail in The CIE Microprocessor Trainer helps you to Seam how circuits with microprocessors function in computers. the handy reply coupon or card below to: Cleveland Institute of Electronics, 1776 East 17th Street, Cleveland, Ohio 44114. r CIE ARE-157 World Headquarters Cleveland Institute of Electronics, Inc. 1776 East 17th Street • Cleveland, Ohio 44114 □ Please send your independent study catalog. For your convenience, CIE will try to have a representative contact you — there is no obligation. Print Name Address City. Age. Stale .Apt. ■ 2p- . Area Code/Phone No._ Check box for G.l. Bill bulletin on Educational Benefits D Veteran □ Active Duty MAIL TODAY! Just call toil-free 1-800-321-2155 (in Ohio, 1-800-362-2105) > 2 C > — i. to S o 31 OZONE-SAFE AEROSOLS. When possible, ozone-de- pleting CFC's (Clorofluoro Carbons), which are typ- ically found in aerosols, have been totally eliminated from Chemtronics' E-Series of chemicals. In all other cases, E-Series' formulas ex- ceed the recommended 20% cut-back in regulated CFC's. The E-Series consists of four products. Ultrajet is a microscopically clean, moisture-free source of "canned air" for applica- tions where "ultra-pure" cleaning is required. It fil- ters its compressed gas to less than 0.2 microns and CIRCLE 31 ON FREE INFORMATION CARD delivers a powerful 120 PS I jet action that instantly re- moves dust, lint, and oxide particles from all kinds of electronic equipment, op- tical surfaces, and precision instruments. Freez-lt quick- ly cools circuits to -%°F, leaving no residual film, to provide positive diagnosis of thermal intermittents. Flux-Off Plus solvent re- moves flux, soldering oils, and production con- taminants from electronic subassemblies, PC boards, and other electronic com- ponents. It penetrates even tightly packed components and evaporates completely, leaving surfaces dry and res- idue free. TF Plus is a mild cleanser and degreaser for use on solvent-sensitive equipment and precision instruments. It removes dirt, grease, and molding compounds on contact, evaporates completely leav- ing no white residue, and is safe for use on delicate plas- tics and elastomers. For container sizes and prices of E-Series products contact— HUB Material Company, 33 Springdale Av- enue, Canton, MA 02021. DIGITAL STORAGE SCOPE/ MULTIMETER. A combina- tion 2-channel digital stor- age oscilloscope and digital multimeter from Leader In- struments, the model 200, allows two-channel com- parisons, addition or sub- traction of two signals, and X-Y capability. The portable 2'/z-pound instrument runs on batteries or AC power. The model 200's os- cilloscope section has a 3- MS/s maximum sampling rate and is completely auto- ranging. The optimal wave- form is displayed by touch- ing the auto-timebase and vertical-sensitivity buttons, and the standard printer in- terface allows waveforms and setting conditions to be output to an optional dedi- cated printer (model 710) for -hard-copy documentation. Sensitivity, timebase, trig- ger source, slope, and dis- play mode are displayed on screen. The memory banks CIRCLE 32 ON FREE INFORMATION CARD can store three waveforms per channel; in addition, the model 200 is battery- backed for long-term stor- age of all six waveforms. The autoranging DMM has a manual override fea- ture as well as audible con- tinuity and overload indica- tors. It offers AC/DC voltage and current measurement functions, resistance, and a low-power ohm mode to provide a lower test voltage for in-circuit resistance measurements. The model 200 combina- tion digital storage os- cilloscope/multimeter has a suggested price of $1,645.00; the model 710 printer costs $480.00.— Leader Instruments Corpora- tion, 380 Oser Avenue, Hauppauge, NY 11788. R-E O z o tr h- O LU _l LU Q Q < cr 32 A New AOR Scanner 100 Channels Low, Air, High, UHF & 800MHz AR950 Tolil Plica, Frtigh.1 Prepaid (Express Shipping! Optional) 299 00 ■ Perfect for base or mobile. Includes AC and DC power cords, mobile mount hardware and 1 antennas. ■ Covers 27-54MHz, 108- 174MHz. 406-S 12MHz and 330-9S0MHz. ■ 5 Scan Banks and 5 Search Banks ■ 26 Day Satisfaction Guarantee ■ No Frequencies Cut Out. ■ Size: 3WH x SVs"Wx 2WD. Wt.: 2 lb. 10 oz. COMMUNICATIONS 10707 £. 1061h St. lndpls., IN -16256 Toll Free 800-44S-I21I p-*-^ Visa and MasterCard i*iB*iiCu^ ( COD si ightly h itjher) l\r*--^i In 1 ndiani 3 17 ■ a 49-2S70 Colled FAX (317)849-8794 Versatile Lab Power Supply CIRCLE 152 ON FREE INFORMATION CARD MODEL 3002A SHOC00 ^o ,125 Only • 0-30 VDC at 0-2A • Excellent Regulation • Ripple & Noise - 500 uV RMS • Built-in Short-Circuil and Overload Protection Model 3002 A features continuously adjustable current limiting and precision constant voltage/constant current operation with "automatic crossover" This lab-grade unit can also be used as a current regulated power source. Options: 10-Turn Voltage and Current Controls, S25.00 ea. FREE SHIPPING - 48 STATES. Check, Money Order or C.0.D, (add S3.00). Mo credit cards. IL residents add 7% tax. 15-Day Money Back Guarantee. Save on Quality Test Equipment & Closeouts. Free Literature. Snlen Enterprises, Ltd. P.O. Box 915, Morton Grove, IL 60053 Area Code 312-465-1424 I I \K \ YMI CLEANING/MAINTENANCE/REPAIR EARN UP TO $1000 A WEEK.WORKING PART TIME FROM YOUR OWN HOME! CIRCLE 149 ON FREE INFORMATION CARD THE MONEY MAKING OPPORTUNITY OF THE 1990 S IF you are able to work with common small hand tools, and are familiar with basic electronics (i.e. able to use voltmeter, understand DC electronics). . . . IF you possess average mechanical ability, and have a VCR on which to practice and learn. . . .then we can teach YOU VCR maintenance and repair! FACT: up to 90% of ALL VCR malfunctions are due to simple MECHANICAL or ELECTRO-MECHANICAL breakdowns! FACT: over 77 million VCRs in use today nationwide! Average VCR needs service or repair every 12 to 18 months! Vlejo's400 PAGE TRAINING MANUAL (over 500 pho- tos and illustrations) and AWARD-WINNING VIDEO TRAINING TAPE reveals the SECRETS of VCR mainte- nance and repair— "real world" information that is NDT available elsewhere! Also includes all the info you'll need regarding the BUSINESS-SIDE of running a successful service op- eration! FREE ihpormatION CALL TOLL-FREE 1-800-537-0589 Or write 1o: Viejo Publications Inc. 3540 Wilshire BL STE. 310 Los Angeles. CA 90010 Dept. RE CIRCLE 143 ON FREE INFORMATION CARD Electronics DTfflmD^E SIMPLY SNAP THE WAT-50 MINIATURE FM TRANSMITTER on top of a 9v battery and hear every sound in an entire house up to 1 mile away! Adjustable from 70-130 MHZ, Use with any FM radio. Complete kit $29.95 + $1 .50 S + H . Free shipping on 2 or more! COD add 84. Call or send ViSA, MC, MO. DECO INDUSTRIES, Box 607, Bedford Hills, NY 10507. (914) 232-3878. CIRCLE 127 ON FREE INFORMATION CARD FINAL CLOSEOUT ON ZENITH SSAVI STV-2 UHF used $38 ea./1 00 lot; Oak N-1 2S $45 ea.; MLD-1200s $39 ea.; Sylvania 4040 w/3 remotes S99 ea.; converters & more. Call for list. RADAR SPEEDS GUNS & SYS- TEMS for car, snowmobile racing, skiing, etc. Professional X & K band models. Low prices and 90-day warranty. Makes a great gift! Pre- paid cash & quantity disounts. AIS SATEL- LITE, INC. 106 N. 7th SUE, Perkasie, PA 18944. Orders & catalogs; 1-800- AIS-2001; tech. info: 215-453-1400. CIRCLE 81 ON FREE INFORMATION CARD FREE CATALOG OF HARD-TO-FIND TOOLS is packed with more than 2000 quality items. Your single source for precision tools used by electronic technicians, engi- neers, instrument mechanics, schools, labo- ratories and government agencies. Also contains Jensen's line of more than 40 tool kits. Send for your free copy today! JENSEN TOOLS INC., 7815 46th St., Phoenix, AZ 85044. (602) 968-6231. CIRCLE 115 ON FREE INFORMATION CARD CALL NOW AND RESERVE YOUR SPACE • 6 x rate $940.00 per each insertion. • Fast reader service cycle, • Short lead time for the placement of ads. • We typeset and layout the ad at no additional charge. Call 516-293-3000 to reserve space. Ask for Arline Fishman. Limited number of pages available. Mail materials to: mini-ADS, RADIO-ELECTRONICS, 500- B Bi-County Blvd., Farmingdale, NY 11735. ACTUAL SIZE The REGEN-I module maintains the volume level of amateur, business (Police, Fire, Power, Fleet, etc.), CB, marine radios and scanners. The REGEN-I will amplify signals and attenuate a strong audio signal keeping volume at a nearly constant level regardless of incoming signal strength and reduce un- squelched FM hiss. Simple installation. $49.95 phone orders OR $39.95 Pre-paid. mail orders only. EMULATION ASSOCI- ATES, 520 GLENBROOK RD, STE 203-B, STAMFORD, CT 06906 SALES: 203- 356-1632 FAX; 203-323-9044 CIRCLE 161 ON FREE INFORMATION CARD AMAZING POCKET REFerence.: 480 pages of tables, formulas, constants, con- versions and maps and it fits in your shirt pocket! (3.2" x 5.4" x 0.6") Chapters include Electronics, Computers, Math, Tools. Glues & Solvents, Chemistry & Physics, Con- struction, Carpentry, Geology, Hardware, Au- tomotive, Air, Water, Welding, Plumbing, Pipe, 1 -800 Airlines, Area Codes, Money, and much, much more. $9.95 + $2.00 shipping (Colorado inc. 56 e tax). Check/Visa/MC. Se- quoia Publishing, Inc., Dept. 950, P.O. Box 620820, Littleton, CO 80162. CIRCLE 138 ON FREE INFORMATION CARD CABLE TV CONVERTERS AND DE- SCRAMBLERS SB-3 $79.00 TRI-BI $95.00 MLD-$85.00 M35B $89.00 JRX-DIC $129.00 Special combos available. We ship COD Quantity discounts. Call for pricing on other products. Dealers wanted. FREE CATALOG. We stand behind our products where others fail. One year warranty. ACE PRODUCTS, P.O. Box 582, Saco, ME 04072 (207) 967-0726. CIRCLE 75 ON FREE INFORMATION CARD APPLIANCE REPAIR HANDBOOKS— 13 volumes by service experts: easy-to- understand diagrams, illustrations. 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Counter $249 fSine, Square, Triangle Pulse, Ramp. .2 to 2MHz Freq Counter .1 ■ 10MHz GF-B015 without Freq, Meter $179 5 Year Warranty £BII 5/10MHZ Motherboard B Expansion Slots Math Compressor Slots 360 K Floppy Drive AT Style Keyboard FREE spreadsheet and word processor 3.XXMS DOS and GW Basic add 75.00 150W Power Supply 256KRAM Expandable to WOK Monochrome Monitor Monographic Video Card Parallel Prinler Port WE WILL NOT BE UNDERSOLD! *p & C CAT fS INC 15 Da y Mt > n ey Back Guarantee UPS Shipping: 48 states 5% r^g— ,^ s SsSoSuDmflS. 1L 60015 2 Year Warranty phc* »** * a^ ($10 Max) IL Res., 7% Tax C±r*gg|g (gfjo) 292-7711(708) 541 0710 WRITE FOR FREE CATALOG CIRCLE 109 ON FREE INFORMATION CARD D '21 IF YOU'VE SEEN A RECENTLY PRODUCED motion picture presented in a modern theater, then you are undoubtedly aware of the stunning realism and dra- matic impact created by the use of the Dolby-stereo surround- sound audio process. The system was developed by Dolby Laboratories for the mo- tion-picture industry to literally sur- round viewers with sound and place them in the very midst of the action. For anyone unfamiliar with the concept, the Dolby-stereo surround- sound process works to increase the sensation of "being there" by re- producing distinct sounds toward the front, sides, and rear of the viewer. In practice, it is accomplished by feed- ing the primary stereo soundtrack to speakers located behind the screen on the left, the center, and the right side of the theater. Simultaneously, an additional au- dio channel, decoded from within the primary channels, is sent to a system of smaller speakers located to the sides and to the rear of the audience. That additional surround channel is used to re-create ambient sounds like wind noise or "on location" street sounds as well as special sound effects intended to travel past the au- dience from front to rear, or even to seem to circle overhead. Since the mid 1970's, over 1100 motion pictures have been produced with surround-sound tracks. Because the process encodes the surround in- formation into a 2-channet stereo sig- nal, when the movies are transferred to video tapes and laser discs, the encoded information remains intact. However, in order to enjoy surround sound at home, at the very minimum, a stereo VCR; some type of decoder, and additional surround speakers are required. The basic principle of all surround- sound decoders, from the simplest to the most expensive, is the same. They all reproduce the surround informa- tion by recovering the (L — R) dif- ference signal which is encoded into the left and right channels of the movie soundtrack. The decoder pre- sented here goes beyond the ca- pabilities of a simple surround-sound decoder. Besides the surround de- coder circuit, additional circuitry is ACOUSTIC FIELD GENERATOR Our AFG will turn any Hvingroom info a full-sized movie theater or concert hall. TOD T. TEMPLIN > z > -c CD ID O 35 C23 MP J2 INPUT* R1I< 47K? FHSHT@H(- INPUT' ■ 75H; LOW PASS FIG.3 SLJBWOOFER LEVEL DELAY SECTION FIG. 4 CENTER CHANNEL BANDPASS FILTER FIG.2 F79$. IK -' SURROUND LEVE L R73^, f R32 1IC SUBWOQFER OUTPUT TO LEFT i POWER AMP TFIG.E TO RIGHT POWER AMP 7fcC22 SURROUND J 1 OUTPUT -CL S3-a 3 ib -Qj S3-6 i— O \} BYPASS -o \o S4-S l-O S4-b R28 150! 1 FIG. 1— THE AFG IS MADE UP OF 10 relatively simple circuit elements. O z :: a: F O LU o q < TO S3 OUTPUT AWr-O C50 .012 FIG. 2— THE CENTER-CHANNEL SPEECH FILTER is built by cascading a 3-kHz low-pass filter with a 300-Hz high-pass filter to form a band-pass filter. used to create wide-left, center-di- alogue, wide-right, and subwoofer signals. Presenting those signals through six properly arranged speak- ers results in the acoustical illusion of a large, almost boundless, three-di- mensional listening environment, even in a small room: hence the name. "Acoustic Field Generator," but we'll call it the AFG for short. This article is not intended to provide an in- depth tutorial or technical description of the surround-sound system. Rather, it is intended to show you how to construct and install a high-quality. multichannel sound decoder for use in your home. The AFG offers two different modes of operation; "matrix' 7 and "concert." In the matrix mode, the (L-R) difference signal is recovered from surround-encoded source mate- rial and is then passed through a 2048- stage bucket-brigade delay line. The delay is continuously adjustable from about 5 to 35 milliseconds, and has a bandpass of 50 Hz to 15 kHz. That enables the accurate decoding and presentation of the surround-channe! information present within the source material. The (L + R) sum signal is also recovered to be sent through the delay section of the AFG when the concert mode is selected. That im- parts the ambience and realism of a live concert- hall performance to mu- sical material played through the AFG. In either mode, the output of the decoder/delay section is sent to a pair of lO-watt-per-channel power 36 amplifiers, included on the main cir- cuit board, for driving a pair of sur- round-channel speakers. The AFG also provides a means of greatly increasing the apparent sepa- ration or "width" of the stereo image presented by the front speakers. In an ordinary decoder, the left- and right- channel signals are sent to the front speakers unaltered, and the center channel, if present at all, is fed a simple sum of the left and right sig- nals. Although that technique pro- vides a very solid front soundstage, it severely limits the system's ability to convincingly present extreme-left or - right sound effects. And, because the screen in most home- video systems is relatively small, especially when compared to the screen in a movie theater, dialogue which should be confined to the screen, tends to appear off screen in the left and right speak- ers — particularly for viewers seated off center. The AFG uses frequency-selective circuitry to cancel some of the di- alogue from the left and right chan- nels, but that creates a phantom "hole" in the center of the sound- stage. So, the AFG also creates a cen- ter dialogue channel to fill that hole by summing the left and right chan- nels and passing them through a band- pass filter with a response curve which favors the range of frequencies covered by the human voice. Feeding the voice-only "dialogue" signal di- rectly to the speakers in the video monitor locates the dialogue firmly on the screen without destroying the spatial effects of the front soundstage. Finally, the AFG includes a 75-Hz active low-pass filter for driving a sub- woofer setup. If you are not currently using a sub woofer as part of your sys- tem, you are missing out on the dy- namic impact and heightened level of excitement which is imparted by the extreme low- frequency sounds used in motion pictures, primarily as a spe- cial audio effect. The subwoofer out- put of the AFG has that sonic information isolated and ready to feed to a power amplifier and speaker of your choice, 'feu may wish to consult with a local audio dealer for advice on selecting a proper subwoofer and power amplifier. Suffice it to say, that a relatively high-power amplifier and large subwoofer will be required if you intend to fiil your room with earth-shaking bass that goes far beyond the capabilities of most "full- PARTS LIST All resistors 14- watt, 5%, except as noted. R1— 1500 ohms R2, R3, R54— 22.000 ohms R4, R5, R32, R33— 1000 ohms R6, R7 r R61, R62, R74— 20,000 ohms R8, R9— 1 ohm, 1 / 2 -watt, 5% R10-R13, R19, R34, R35— 47,000 ohms R14-R17, R20-R25, R47-R49, R55, R56— 100,000 ohms R18, R57— 330,000 ohms R26-R31, R66, R70— 150 ohms R36-R43, R67— 8060 ohms, 1% R44-R46— 16,000 ohms R50, R51— 5600 ohms R52— 2400 ohms R53— 8200 ohms R58-R60, R63-R65, R71-R73— 10,000 ohms R68— 9530 ohms, Yt-watt, 1% R69— 102,000 ohms, V-t-watt. 1% R75, R80— 100,000 ohms, potentiometer R76 — 10,000 ohms, potentiometer R77— 50,000 ohms, PC-mount potentiometer R78, R79— 1000 ohms, PC-mount potentiometer Capacitors C1-C4— 2200 fiF, 25 volts, electrolytic C5, C6— 10 |xF, 35 volts, radial electrolytic C7-C12, C19-C22, C27, C28, C30, C31, C45, C49, C58— 0.1 pF, 50 volts, metal film C13, C14, C23, C24, C43— 2.2 pF, 50 volts, bi-polar radial electrolytic C15, C16— 22 p.F, 16 volts, bi-polar radial electrolytic C17, C18— 0.22 p.F, metal film C25, C26—0.047 ^F, metal film C32-C34— 3300 pF, polyester C36, C37— 2700 pF, polyester C38-C41— 270 pF, 5% ceramic disc C42, C47— 0.47 ^.F, metal film C44 — 120 pF, 5% ceramic disc C46— 0.56 p.F metal film range" speakers. It is preferable to place the subwoofer toward the front of the soundstage, although the exact position is not critical, due to the ear's inability to accurately locate very low- frequency sound. Thus, many sub- woofers are designed to physically re- semble an end table or other piece of furniture, so that they can aesthet- ically blend into the other room decor. The AFG was designed to be con- nected into the pre-amp/power-amp loop of your regular home entertain- C48— 0.039 n,F, metal film C50— 0.012 fxF, metal film C51, C56— 0.01 jjlR metal film C52— 1000 pF, 5% polyester C53-C55— 0.027 fjuF, metal film C57— 5600 pF, 5% polyester C58— 4700 pF, 5% polyester C59 — 470 pF, 5% ceramic disc Semiconductors D1 , D2— 1 N5400 50 PIV 3-amp diode IC1-IC4— LF347 quad JFET IC5— MN3008 2048-stage bucket brigade device IC6— MN3101 2-phase clock IC7— 7812T +12-volt regulator IC8— 7912T -12-volt regulator IC9, IC10— LM1875T audio amp LED1 — light emitting diode pilot lamp Other components T1 — Power Transformer 25,2 Volt Center Tapped 2 Amp. F1-F3 — 1-amp fuse J1-J8 — 8-pin RCA-style jack panel J9-J12 — 4-position pushbutton speaker-terminal panel S1, S2, S5—SPDT switch S3, S4— DPDT switch Miscellaneous: speakers of your choice, 5 14-pin IC sockets, 1 8-pin IC socket, 1 heat sink (2 x 2 x S'/t- inch aluminum angle stock), 2 T0-220 mica insulators with mount- ing hardware, silicone grease, 3 in- line fuse holders, 3 knobs, chassis, linecord, solder, etc. Note: The following items are available from T3 Research, Inc., 5329 N. Navajo Ave., Glendale, Wisconsin 53217-5036: An etched, drilled, and plated PC board, $15.00; a basic parts kit consisting of all semiconduc- tors, resistors, and capacitors, $55.00; a piece of aluminum stock for the heat sink, S3. 00. Piease include $2.50 for postage and handling with your order. Wisconsin residents please in- clude appropriate sales tax. ment system. Consequently, all the functions of the AFG may be switch- ed to bypass and unity gain to effec- tively remove it from the system, if required. We believe, however, that once you experience the added sonic dimension that the AFG adds to mu- sic as well as movies, you'll never want to switch it off. About the circuit When viewed as a whole, the AFG circuitry is quite complex. However, > < o 37 referring to the simplified schematic in Fig. 1, you can sec that the AFG is really made up of 10 relatively simple circuit elements. ICl-c and ICl-d are configured as unity-gain non-invert- ing buffer amplifiers. They transform the 47-kilohm input impedance, which is set by RIO and Rll, to a low- impedance source which drives all of the AFG amplifiers, filters, and by- pass outputs. The summing (L + R) amplifier, IC2-c, combines equal amounts of the left and right signals, via R14 and R15, to develop a total composite sig- nal. Left- and right-channel signals are applied equally through R13 and R12 to IC2-d, the difference (L-R) decoder. Any signal that's common to both channels is canceled by lC2-d, thus forming one signal which con- tains none of the common "mono" information present in the original stereo signal . Potentiometer R80 pro- vides a means of exactly balancing the inverting and non-inverting gains of the amplifier for a perfect null. The stereo width-enhancement cir- cuit is made up from ICl-a and ICl-b. It works similarly to the (L-R) de- coder, except that C25 and C26 have been added in the inverting inputs of each op-amp. Consider, for the mo- ment, just the "right wide" circuit of ICl-a; C26 and R23 form a gently sloping high-pass filter for the left- channel signal only Thus, the amount of signal cancellation is dependent on frequency and the relative amplitude between the two channels. In other words, the more a signal is the same in both channels, the more it is re- moved from the output of the circuit; the effect increases as the signal's fre- quency rises. If, however, the input signal appears only in the right chan- nel, no matter what its frequency or amplitude, it does not cancel in the difference amplifier and appears at the output unaffected. ICl-b functions in the same way to develop the "left wide" signal be- cause its inverting and non-inverting inputs are connected to the left and right channels in a manner opposite that of ICl-a. The net effect of all that is to increase the apparent separation between the left and right channels by eliminating some of the material com- mon between them . The output of the width-enhancement circuit is routed to S4, which selects either the "wide" or the bypass signal for feed- ing the front-channel amplifier. The center-channel dialogue filter, or speech filter if you prefer (see Fig. 2), is built by cascading a 3-kHz low- pass filter with a 300-Hz high-pass filter to form a band-pass filter. The frequency characteristics of the human voice fall predominantly with- in that range. As with all of the other filters used in the AFG, those are of the 3rd order Butterworth design. That design was chosen because it offers minimum peaking within the passband. It has a sharp -18 dB/ octave cutoff, a flat voltage and power frequency response, and minimum phase change within the passband. The output of the bandpass filter is routed to the high side of S3. That switch allows the center-channel out- put of the AFG to be switched be- tween the dialogue filter and the by- pass mode. As shown in Fig. 3, IC3-aandIC3- b form an active crossover network for driving a sub woofer. IC3-a sums sig- nals from the left- and right-channel buffer amps, it inverts the summed signal 180 degrees, and it provides a low driving impedance for the follow- ing filter stage. IC3-b and its associ- ated RC network form a 75- Hz, 3rd- order low-pass filter. Because the filter inverts the signal another 180 de- grees, the signal that appears across R79 (which is the output-level con- trol) is back in phase with the original input signal. The delay section of the AFG, shown in Fig. 4, is built around the MN3008 Bucket Brigade Device (BBD), made by Matsushita (Pan- asonic), and the MN3101 two-phase variable-frequency clock generator. The BBD is a P-channel silicon-gate MOS LSI circuit comprised of 2048 bucket-brigade stages fabricated on a single chip. Each stage consists of a small capacitor that stores an electric charge and a tetrode transistor for INPUT FROM LEFT R55 BUFFER 100K O— VA- switching purposes. Electrical charges corresponding to analog sig- nals are transferred from one stage to the next by a two-phase clock drive, in the same manner that a fireman's bucket brigade transfers a pail of water from one man to the next. A signal presented at the input is trans- ferred down the line of buckets toward the output at a speed controlled by the clock frequency. The more slowly the clock runs, the longer it takes for the signal to travel through the circuit. (See discussion of BBD theory in the October 1986 Radio-Electronics.) The amount of delay required in our system varies between approximately 5 and 35 milliseconds, so our first consideration must be to select the proper range of clock frequency. The delay time of a BBD is equal to the number of stages divided by twice the clock frequency. So, based on man- ufacturer's data for the MN3101 clock-generator IC, values were chosen for R53, R54, R77, and C44, to produce a clock frequency, adjusta- ble via R77, which varies from about 30 kHz to 130 kHz. Our next consideration deals with the property of delay lines known as aliasing. If the frequency of the signal applied to the input of a delay line becomes higher than one half of the clock frequency, the time available to store the sample of that signal in the capacitor becomes too short. The am- plitude of that signal's frequency has a value which changes during the time of the sample, so the charge stored in the capacitor is not an accurate repre- sentation of that instant of time. To avoid the problem and the resulting distortion, a filter is placed ahead of the BBD which limits the input fre- quency to one half of the lowest clock frequency used. Given that we'd like to run the clock at speeds as slow as 30 kHz, we must limit the maximum fre- rVW INPUT FROM RIGHT SUFFER R56 1Q0K FIG. 3— AN ACTIVE CROSSOVER NETWORK for driving a high-power subwoofer system is made from IC3-a and IC3-b. 38 INPUT FROMO- SI FIG. 4— THE DELAY SECTION OF THE AFG Is built around the MN3008 bucket-brigade device and the MN3101 two-phase variable-frequency clock generator. quency that we apply to the BBD to 15 kHz. If you refer back to Fig. ], SI se- lects the signal to be delayed; either the difference signal (L — R) from IC2-d in the matrix mode or the sum signal (L + R) from IC2-c in the con- cert mode. The selected signal is fed from SI to the delay section (Fig. 4) where IC4-d is configured as an inver- ting amplifier; R75 adjusts the gain between unity and X3. Integrated cir- cuits IC4-a and IC4-b. along with their associated RC networks, are identical 3rd -order 1 5 -kHz low-pass lilters. Cascading two filters produces a very sharp cut off ( - 36 dB per octave), which is convenient, as it eliminates any problems that may arise with aliasing, while maintaining a respectable 15-kHz bandwidth for the section. Potentiometer R76 is used to adjust the bias voltage re- quired by the BBD to exactly one half the supply voltage; a requirement of the device. Notice that both the BBD and the clock IC run off of the nega- tive power-supply rail. Another property of a BBD is that clock phase 1 drives all the odd- number stages of the device and clock phase 2 drives all the even stages. When the signal reaches the end of the line, the output of the last odd stage must be combined with the output of FIG. &— A3rd-ORDER 7-kHz LOW-PASS FILTER is made from 1C3-C and its associated RC network. the last even stage to reconstruct an exact replica of the input signal. The purpose for doing that is to self-cancel any of the clock signal from the out- put of the device; R48 and R49 are the source-load resistors for the last two BBD stages and R50 and R5I sum the two outputs. The delayed signal is next applied to another 3rd-order 15- kHz low-pass filter comprising 1C4-C and its associated RC network. That last filter is required to stop any re- maining clock signal from reaching the oulpul of the circuit. Potentiome- ter R78 is there to serve as the volume control for the surround channels by controlling the amount of delayed sig- nal that is applied to the power ampli- fiers. To provide for increased high-fre- quency noise reduction in the sur- round channel and to more closely comply with the Dolby Laboratories standards for surround sound, a 3rd- order7-kHz low-pass filter is included in the AFG design. As shown in Fig. 5, 1C3-C and its associated RC net- work forms the filter; S2 then selects between the output of that filter and the bypass mode. If you refer back to Fig. 1, notice that the wiper of S2 is connected to two circuits; it goes di- rectly to the left surround power am- plifier via R31, and to IC3-d, a unity- gain inverting amplifier, via R32. The output of IC3-d drives the right sur- round power amplifier via R30. The reason for driving the power ampli- fiers out of phase will be explained shortly. > z c > 13 -C (D ID O 39 L INPUT O ■: Br. - o _l D < DC FIG. 6— THE SURROUND CHANNEL POWER AMPLIFIERS are designed around a pair of LM1875 monolithic power-amplifier IC's. TO LEFT POWER AMP TO RIGHT POWER AMP o — -18V n GROUND •_]_ a .CHASSIS T 2Z00ttF . r — < * *■ /T777 T* D1 C3 1N510D 2?!%F' -h- -M- C2 T* 220QM-F D2 C4 4J 1N5400 220Q|iF TO LEFT POWER AMP o- -18V IC7 7812 POWER GROUND + * 2®^ 1.5K C5 Jj" 2200jjlF ' ~ C6 IC8 7912 J_ 019 .1 -0 ■ 12V . AUDIO GROUND -O 12V TO RIGHT POWER AMP FIG. 7— THE POWER SUPPLY produces about ±18-volts unregulated DC. FIG. 8— THE PROTOTYPE ACOUSTIC FIELD GENERATOR. It's a tight fit in this cabinet, but it makes for a neater finished unit. The surround channel power ampli- fiers of the AFG, shown in Fig. 6, are designed around a pair of LM1875 monolithic power-amplifier IC's. Chosen primarily because they re- quire very few external parts to imple- ment, and they also offer very low distortion, fast slew rate, wide power band width, and the ability to deliver up to 20 watts into an 8-ohm load: all in a 5-pin TO- 220 package. Because of limited heat-sink space in the AFG, we are running the LM1875 at about half of its power capability. The cir- cuit configuration of the power amp is essentially the same as that of any ordinary op-amp operating in the in- verting mode. Notice however, that there are two separate ground-return lines to the power supply. That is nec- essary because high currents flow through the output ground-return line. If a common ground-return line were used for both the input and out- put signal, those currents could de- velop enough voltage across the resistance of the return line itself to effectively act as an input signal to the amplifier, thus causing problems such as high-frequency oscillations or dis- tortion. The power supply of the AFG, shown in Fig. 7, is of conventional design. A 25-volt center-tapped trans- former, along with diodes Dl and D2, produces about ± 18-volts unregu- lated DC. Two 2200-p.F filter capaci- tors are used in each leg of the supply to provide ample energy storage to meet the high-current demands of the audio output amplifier IC's during high-output peaks. Integrated circuits IC7 and IC8 regulate the positive and negative supply rails to plus and minus 12 volts for use in the low signal level circuits. The plus and minus 12- and 18-volt rails are bypassed to ground by O.l-ixF capacitors dis- tributed throughout the entire AFG circuitry. That keeps the impedance of the supply rails at audio frequen- cies as low as possible, thus reducing the interaction between the various circuits. That's all we have room for this time. We've given you the list of parts, so that you can at least gather all of them together. Next month we'll give you the foil pattern and parts- placement diagram so you'll be able to build your own AFG. \bu'll find that more fun than just looking at ours which, by the way, is shown in Fig. 8. R-E 40 RAHJ M JD MICROPROCESSOR SYSTEMS OFTEN monitor several signals at once, like address or data bus contents. That's often difficult to duplicate with most logic probes, and logic analyzers are too expensive for most hobbyists. One solution is to build an eight-bit, 3-chip, word-recognition logic ana- lyzer for about $6. The low parts cou- nt keeps size and power demands low, so it can run directly off the Cir- cuit-Under-7est (CUT). Principles of operation The schematic is shown in Fig. 1. It uses two cascaded four-bit 74LS85 digital magnitude comparators, 1C1 and IC2. to monitor an eight-bit sig- nal in any TTL-compatible environ- ment. The digital word being sent is entered on a group of DIP switch in- puts (Sl-a-Sl-h), If it's matched by signals from the test device inputs (TP0-TP7), the upper 74LS85 sets pin 6 high. The 74LS00 is a quad 2-input nand gate; IC3~a and lC3-b make up an R-S flip-flop, IC3-C is unused, and IC3-d is used as an inverter to drive one fiip- fiop input. The two llip-fiop inputs are pin I on IC3-a, and pin 4 on IC3-b. Pin I on IC3-a is kept high by being tied back to +5V through R3-L Pressing the RESET switch, S2, mo- mentarily grounds pin I of IC1 and pin 6 of KS, turning off Ql and LED I. The high from pin 6 of IC2 sets the flip-flop, driving pin 6 of the 74LS00 high, turning on Ql and LED I until the user presses S2. However, test points TP0-TP7 shouldn't have latched yet. A comparison ripples through a 74LS85 in about 32 micro- seconds (worst case), so each eight- bit word has to last about 64 nanose- conds for valid comparison. That shouldn't cause problems with 4-8 MHz microprocessor signals. Construction The prototype, shown in 2, was buill on a PC board using wire wrap IC sockets and a nine-elenient SIP- resistor array. The tes should be about six inches long push-on connectors are single, break- apart, Molex IC sockets, covered with heat-shrink tubing; you could also use 3-CHIP LOGIC ANALYZER If you have ever needed a simple logic analyzer, or wanted to know more about how they work or how to use them, then try our $6 circuit. J.J. ROBINSON II w o z o EC h- o LU _l LU o 5 < FIG. 1— SCHEMATIC OF THE 3-CHIP LOGIC ANALYZER. It's made Irom two cascaded 74LS85 4-bit magnitude comparators (IC1 and IC2), and uses an 8-switch SPSP DIP switch St and 8- resistor SIP array R3 to set the bit states compared against. The output of IC2 is fed into inverter IC3-d, which feeds into RS flip-flop IC4-a and b, which drives Q1 and LED1. an IC test clip. The space between the PC board and the tested circuit has to be insulated with a sheet of plastic or small block of wood. At high frequen- cies, use a shielded enclosure. The prototype PC board operated reliably when unshielded near a 16-MHz vid- eo PC board. Testing The circuit can be tested with a static input word on the test leads. When the analyzer's switches (S1-S8) match it, LED1 should light. If the switches are then changed so they no longer match, LED! should stay lit. If S2 (reset) is now pressed, LED1 should go out. If that doesn't happen, carefully check your work for wiring errors. Applications There are three tests for which the analyzer is quite useful: • Data bus: Connect the test leads in the correct order to the micro- processor data bus, and check for the desired eight- bit test word. They can be elements of the machine language program, data transmitted to the mi- crocomputer by another device, etc. • Address bus: Connect the test leads to the address bus; since it's often 16 bits long, only half can be monitored at once. The upper half will usually be the most significant, and will show what parts of the ad- dress space the system is accessing under program control . • Control signals: Connect the test leads to monitor a selection of control PARTS LIST All resistors are 'A-watt, 5%. R1, R2— 10,000 ohms R3-a-R3-i— 10,000 ohms x 9 SIP network Capacitors CI, C2 — 0.1 n.F, ceramic disc Semiconductors IC1, IC2— 74LS85 magnitude comparator IC3— 74LSO0 quad nand gate Q1— 2N2222 NPN transistor LED1 — light-emitting diode Other components S1-a-S1-h— 8-switch DIP S2 — subminiature, momentary, push-button SPST switch TP1-TP8— Molex break-apart IC pins Miscellaneous: PC board, wire, sol- der, and heat-shrink tubing. FIG. 2— PROTOTYPE OF THE 3-CHIP logic analyzer; note SPST DIP switch S1 and the SIP resistor array R3 at upper left. The eight pins covered with heatshrink tubing are made from Molex break-apart IC pins. signals, like chip-, write-, and read- enable (CEj we, and re) pins of memo- ry devices, I/O selects, etc. That can show whether the ce, we, and/or re are simultaneously active, whether multiple memories are simulta- neously selected, and happens to be very useful in debugging address de- coding algorithms. To use the analyzer, connect the power and ground to the test circuit points, and the eight test leads to the appropriate signals. When a positive match is found, the LED glows. For the next test, enter a new search word and press S2. r-e 42 PHONE ACTIVATED AUDIO-MUTING CIRCUIT Automatically silence your stereo or TV as soon as your telephone rings IF YOU'RE USING A TELEPHONE. THE SOUND from a radio, stereo, or TV can be annoying. To avoid that nuisance, build this phone-activated audio-mu- ting circuit. It cuts off the audio from a radio, stereo, or TV when your phone rings, or when the handset is picked up to make an outgoing call. About five seconds after a phone is hung up or stops ringing, the audio resumes. To use the audio-muting circuit, just connect it anywhere prior to the speaker(s) of your radio, stereo, or TV. That applies to low-power mono or stereo audio, whether from a radio, stereo system, or TV. For use with high-power audio (above 20 watts), place it between preamp and power amplifier. Most recent stereo gear has a rear- pane I jack for audio-signal pro- cessing like enhancement or com- pression prior to power amplification. If your equipment doesn't have such a jack, and if you're not using a sepa- rate preamp and power amp, you might want to install the audio-muting circuit in the tape loop. Circuit description The schematic of the audio-muting circuit is shown in Fig. I . A standard phone line has about 48- volts DC on it when open (on hook), and about 5- volts DC when in use (off hook). The ring signal is a low- frequency AC voltage superimposed on the DC. Ro- tary phones dial by intermittently making and breaking the phone- line connection, toggling it from 5 to 48 volts and back. That is, the number of make/break pulses in a single rotation of the dial represents the number being dialed. About five seconds after the phone is hung up or stops ringing, the audio resumes. The reason for that delay is that rotary-dial phones operate by making and breaking a phone line connec- tion, and the central-office equipment would count the number of pulses for each digit of a phone number. If the delay weren't present, the audio would be cut off when the phone handset is lifted up, but when a number is dialed, the user would hear the pulses of the dial intermittently PU PHONE LINE INPUT YELLO W GREEN BLACK FIG. 1— SCHEMATIC OF THE AUDIO-MUTING CIRCUIT; RY1 switches audio inputs J1 and J2 through J3 and J4, respectively, or shorts J3 and J4 when the phone on PL2 rings or is picked up. That continues for about five seconds after the phone stops ringing or is picked up. > < O 43 between the audio. The input stage, composed of Rl, 10-volt Zener Dl. and the base-emit- ter junction of Ql. places a high-im- pedance loop across the green (tip) and red (ring) phone- line wires. The current through the phone line should be: 'phone - (^tip *DI *BE|)"^'- = (48 V-IO V-0.7 V)/100K. = 373 u,A. That causes about a 1-volt drop from the 48-volt level, that drives Ql into saturation at about 200 millivolts. If the phone rings or is picked up, Ql cuts off and the inverting input of IC2-a goes to 12 volts. Next, voltage divider R3-R5 biases the nonin vert- ing input of IC2-a and the inverting input of IC2-b at: V B1AS = V CC X[R3/(R3 + R5)1, = 12 Vx[20K/(20K + 10K)]. = 8 V. At that point, the output of IC2-a goes low, discharging C3. The output of lC2-b goes high, turning Q2 on and driving it into saturation via R6. and activating relay RY1, breaking the au- dio path between J 1 and J2,and J3and J4. After the phone stops ringing, or is hung up. the output of lC2-a goes high, charging C3 through R4, with a time constant of: T = R4XC3 = 100KX47 (ulF = 4.7 seconds. If the phone rings before C3 reaches 8 volts as set by R3 and R5. C3 discharges and the timing cycle restarts. After a certain exponential charging interval, the potential across C3 reaches 8 volts, and the output of IC2-b goes low, turning off Q2 and RY1 and reconnecting the audio. The final charging voltage in that case is V f = V cc = 12 V, and the target volt- age is V, = 8 V. Since t is known, the charging interval is: T = -2.303 Xt x Log m [l-(V,/V r )], =-2.303x4.7 seconds xLog m (H8 V/I2V)], = 5.164 seconds. When RY1 eneraizes and the audio PARTS LIST — is cut off, audio output terminals J 3 § and J4 are shorted through C4 to pre- o vent any hum introduced when the Ij audio-mutina circuit switches line- ^ level audio. Here, D2 prevents re- 5 verse-bias spikes, generated by lr switching RY1, from destroying Q2, All resistors are Vi-watt, 5%, un- less otherwise indicated. R1, R2, R4— 100,000 ohms R3— 20,000 ohms R5, R6— 10,000 ohms Capacitors C1 — 47 jjlF, 16 volts, electrolytic C2, C4— 0.1 m-F, 50 volts, non- polarized (NP) ceramic disc C3-^t7 fjiF, 10 volts, electrolytic Semiconductors BR1— NTE-5332 1-amp, 600- volt PIV 4-pin DIP bridge rectifier D1— NTE-140A 10-volt Zener diode D2— IN4004 rectifier Q1, Q2— 2N2222 NPN transistor IC1— 7812 5-volt regulator IC2— LM393N 14-pin DIP dual volt- age comparator Other components T1— 120- volt/1 2, 6-volt, 300-mA transformer RY1— 5-volt. DPDT, 8-pin DIP Relay PL1 — AC line cord with plug PL2— four-conductor modular tele- YELLQW phone cord with plug J1-J4 — RCA phono jack Miscellaneous: Case, AC line cord grornmet, two straight-line TO-3 transistor sockets, an 8-pin DIP IC socket, wire, solder, and drill with bits. NOTE: A kit of parts is available for $29,95 from Applitron Services, 2721 Creswell Road, Bel-Air, MD 21014. It includes an etched and drilled PC board, but excludes the AC line plug and cord PL1 with grornmet, modular tele- phone plug and cord PL2, and the case. The PC board alone is S15.00, should you wish to ob- tain the parts locally. Please en- close S1.95 postage and han- dling; allow 4-6 weeks for delivery. Relay RY1 can be ob- tained separately from All-Elec- tronics Corp., P.O. Box 567, Van Nuys, CA 91408, (800) 826-5432, for S2.50. 5 t L2 f | jffi C2 FIG. 2— PARTS-PLACEMENT DIAGRAM for the audio-muting circuit. Note the spacing of the pins of RY1, for orientation purposes. Finally, the grounds for JI-J4 in Fig. 1 are separate from those of the rest of the circuit. The ground symbol for the main part of the audio-muting circuit is the normal downward-point- ing, three-line, triangular arrow, . whereas the ground symbol for JI-J4 is a downward-pointing open tri- angle. The reason is that the radio, stereo, or TV, shouldn't share a com- mon ground with the rest of the audio- muting circuit. Also, the ground terminals aren't connected Jl-to-J3 and J2-to-J4, to attempt to separate the channels and avoid crosstalk. The radio, stereo, or TV will have one common ground for all four terminals within its own cab- inet, so joining all four ground termi- nals of JI-J4 shouldn't make any difference. Similarly, you wouldn't connect Jl-to-J2 and J3-to-J4, since that would isolate input and output, preventing the speakers from being properly grounded, and might damage whatever audio source is con- nected to Jl and J2. You can also use the audio-muting circuit with two mono sources, like two TV's, instead of one stereo source, but you have to isolate the grounds for the two channels. In that case, don't connect ail four grounds for JI-J4 together, or you might get one really nasty shock, and/or some pretty spectacular fireworks. You can connect the grounds of J I and J3 and continued on page 101 44 d 1 6 mWMl WHAT'S NEW IN CD PLAYERS (f you're in the market for a new CD player, you should familiarize yourself with alt of the new features available JOSEF BERNARD WHETHER YOU'RE BUYING A CD PLAYER for the first time, or upgrading your audio system with a new one, 1990 has plenty in store for you. For one thing, you'll find that, as befits to- day's political era, many of the new players are "kinder and gentler." CD players have changed a lot since they were introduced jointly by Phi- lips and Sony in 1983. For one thing, they cost a lot less than the $900 first units, although you can still easily pay that much and more if you put your mind to it. For another, the new play- ers are loaded with features and tech- nology that were barely a gleam in designers' eyes just a few years ago. Here's what's new in the current crop of CD players. Changers It seems that the more we have, the more we want. It isn't enough to have as much as 74 minutes of superior sound recorded on an almost inde- structible medium- — now we don't even want to have to get up to change discs! Enter the CD changer. Changers come in two varieties — ca- rousel and magazine. With a carousel changer (Fig. 1) you load in as many discs as it will hold, usually five, and off you go. When one disc is finished, the next swings into place. Assuming that you always play a given set of discs in the same order, you can pro- gram carousel changers to play selections in a certain order, or even to skip some selections. Magazine- type changers accept car- tridges that can hold five, six, or as many as ten compact discs (Fig. 2). Again, the order in which discs and selections are played is programma- ble. Magazines, which cost between $i5 and $30 each, from different manufacturers are not interchangea- ble, although those used by Sony can be swapped between their home and car units. Most carousel, and some magazine players include a "single- play" drawer for individual CD's. And at least one magazine model has twin drawers (Fig. 3) so you can re- load one while playing the other. Multi-disc players There are now a number of different disc formats on the market offering a number of different types of program- ming. There are conventional five- inch (actually closer to 4%-inches) CD's, the small three-inch discs that offer a shorter "pop-size" playing time, CD-V's for music videos, and 8- and 12- inch laser discs for movies and other visual material. What those formats have in common is that they all involve spinning discs that arc read by bouncing a laser beam off their surfaces. It seemed only natural that someone would eventually come up with a single player that handled all those formats, which are similar in principle, and a quite a few compa- nies have done just that (see Fig. 4). The devices are sometimes referred to as "multi-disc players," (also as "combi players") but the term "multi- disc" refers not to their ability to ac- cept several discs at once, but to their ability to accommodate several dif- ferent disc formats — one at a time, of course. Even some portable units can play both 5- and 3-inch CD's without the adapters that have sometimes been necessary in the past. Programmability One of a CD player's big selling < points, after the quality of its sound, is £ its programmability. You can instruct § 45 c > Take any one of these HANDBOOKS ELECTRONICS and CONTROL • your one source for engineering books from over 100 different publishers • the latest and best information in your field • discounts of up to 40% off publishers' list prices u z o C > J3 < o 49 C/3 O z O DC F o LU 1 LU 6 5 < EC FIG. 1— A CAROUSEL CHANGER, such as Sony's CDP-C8ESD, can accept up to five CD's and ptay them in succession, it can be programmed to skip the tracks that you don't customarily listen to. FIG. 2— WITH MAGAZINE CHANGERS you can store your CD's in sets of five, six, or ten, ready to play in pre-programmed order. The programming information is stored in the changer and called from memory in response to the ID number of the first disc in the magazine. This is JVC's XL-M401BK changer. FIG. 3— IF ONE MAGAZINE ISN'T ENOUGH, changers such as the Pioneer PD- T503 have twin drawers so you can have two on line. You can also reload one magazine while the other is playing. a player to play some selections and skip others (and even to replay the same selections), or decide for itself in what order to play the tracks (ran- dom- or shuffle-play), and take it on its own from there. Some players can play tracks at random while remem- bering to ignore the ones you don't care for. All players have a time display of some sort, which is useful in making up programs to transfer to tape. Some models can be programmed to auto- matically insert a four- second pause between selections, so that you can then use the tapes on players with automatic search functions. There is at least one player on the market that can scan a disc and find the loudest passage, allowing you to set the re- cording levels on your tape deck to prevent distortion. CD changers can be programmed in the same way. The programming information is stored in nonvolatile RAM in the changer. When a maga- zine or, in the case of carousel players, an assortment of discs is inserted into the changer, the first disc is scanned and a manufacturer's ID number unique to it is retrieved from a sub- code (non-music) area. Programming information for a given cartridge is keyed to the ID number, and when a particular number is sensed, the infor- mation pertaining to it is retrieved from the changer's memory. If the first disc in a cartridge is exchanged for another, the program for that car- tridge has to be reentered. The same also applies to disc assortments for carousels. There's one player that can keep track of 226 discs at 20 tracks per disc, for a total of 4520 tracks. The recording format of compact discs allows for index marks to be included by the manufacturer to de- note points on the disc of particular interest. You can enter the index num- bers as you would track numbers to get to those points immediately, or to select certain portions of the disc dur- ing programming. Unfortunately, not many manufacturers take the trouble to include indexing, and the feature is largely unused. A Custom Index feature on some Sony players, though, permits you to enter your own index point (as many as six of them) into the player's mem- ory. When you think you've marked the proper place on the disc, you tell the player: it then replays the three- second passage preceding the marked point to allow you to review and, if necessary, edit the index point. An- other touch of the button locks the index point in memory. If you want to adjust the position of the index point you can do so in increments of V\w of a second using the player's forward and back buttons. Sampling, filters, and extra bits The first stage in converting an ana- log signal to a digital one, such as what's used on CD's, is a process called sampling. The analog-to-digi- tal converter ''peeks" at the analog signal many times each second, and the result of each peek is a number in binary form, or a "sample," that rep- resents the instantaneous amplitude of that signal — its level at the instant of the "peek." The process is illus- trated in Fig, 5. To sample a waveform accurately, 50 the sampling frequency must be at least twice that of the highest frequen- cy that is sampled. If it is lower than that, the digitized signal will not be a proper representation of the analog one, and will be filled with distortion products. In the case of compact discs, the sampling frequency has been standardized at 44. 1 kHz, which ensures reproduction of signals hav- ing frequencies up to (and a bit beyond) 20 kHz, the theoretical limit of human hearing. However, while that technique may record the digitized signal with con- siderable accuracy, the process of playing it back (converting the stream of binary numbers back into an analog waveform that can be amplified and fed to a set of loudspeakers or head- phones) introduces its own set of diffi- culties that must be overcome if accuracy is to be maintained. In the sampling process used dur- ing playback to recover the data stored on a CD, there is an interaction be- tween the frequency of the signal on the disc and that of the sampling clock (which sets the sampling frequency). The interaction, which is known as aliasing, gives rise to sum and dif- ference frequencies that represent ar- tificial (and erroneous) information that never was on the disc. That infor- mation gives rise to distortion and can also waste amplifier power. To get rid of those unwanted har- monics, a technique known as over- sampling is used. Oversampling takes place in a section of the player called the digital filter. In fact, as you shall see, quite a lot happens in a CD play- er's digital filter, and while the re- quired IC's used to be an expensive high-end luxury, they are now found on virtually every player on the mar- ket. As shown in Fig. 6, the filter processes the digital signal almost immediately after it has been retrieved from a disc. Oversampling simply means reading the digital information recorded on the disc at a multiple of the basic sampling rate of 44.1 kHz. That results in the frequencies of the harmonics being so high that most aliasing products disappear (they are filtered out, in effect) and those that remain are far out of the way, where they can cause little problem and FIG. 5— SAMPLING IS THE PROCESS of recording the instantaneous values of a waveform at specified intervals. The Ny- quist theorem states that, for accurate re- production, the sampling frequency must be twice that of the highest frequency of the signal sampled. FIG. 6 — SIGNAL FLOW in a typical CO player. Much of the signal processing that takes place in today's players occurs in the digital filter section. where they can easily be removed by an analog low-pass filter. Oversampling can also increase the accuracy of the information read from a disc to some degree. It is not un- common to find CD players boasting 4x and 8 x oversampling rates, rep- resenting frequencies of 176.4 and 352.8 kHz. Generally speaking, the higher the oversampling rate, the bet- ter the player. Digital filters perform another function. An analog signal that will eventually wind up on a CD is first recorded on magnetic tape in 16-bit digital form, eventually winding up on the disc as a stream of 8-bit digital words that, in turn, represent 14-bit words. (See "Compact Discs Bit-by- FIG. 4 — MULTI-PLAY UNITS can ptay a variety of laser-read discs containing audio or video material. They include 3- and 5-inch CD's, CD-V's, and 8- and 12-inch laser discs. This is the Philips CDV-487. FIG. 7— THERE IS A SIX-DB DIFFERENCE in signal strength represented from bit to bit in the binary words used in digital re- cording for CD's. At the level of bit-0, the least-significant bit, ambiguities in re- cording or decoding can result in an ar- tificial raising of a recording's noise floor. Oversampling and other digital-filter pro- cessing do much to reduce error at that level and expand a player's effective dy- namic range. Bit' 1 Radio-Electronics, August, 1986 for details of the process and c_ information on what else is on a CD z besides music.) > In the early CD players, it was con- < sidered enough merely to decode the S bit stream, convert it back to 16-bit § 51 CO o z O IT H O lit _i LU Q D < rr FIG. 8— OVERS AMP LING ADDS EXTRA data points to the waveform recon- structed from a CD's digital Information. The process yields a waveform that more closely resembles the original one, and also requires less processing. sen ted by the first bit six dB above it. What's needed is some extra bits to smooth things out and eliminate any ambiguity that may try to creep in (that is part of what manufacturers claim as "improved linearity'"). Again, in early players, it was consid- ered sufficient to restore the digital signal to its original 16-bit form. As the speed of D-to-A converter devices increased, though, it became possible Tor them to generate digital words of even greater length than 16 bits in real time from the information contained on a CD. Where do those extra bits come from? They arise from the oversam- pling process and from mathematical operations that are performed on the digital signal within the digital filter which, as now becomes obvious, is more than just a plain filter. Although it is impractical to get into the mathe- matics of the matter here, the Nyquist theorem, which states that the mini- FIG. 9— THE OUTPUT OF PHILIPS' one-bit, 256 x oversampling system is a string of pulses of constant amplitude. The pulse density determines the signal's amplitude. analog form, and pass it through an analog low- pass filter to smooth it a bit and to remove the aliased signals be- fore outputting it to an amplifier. The resulting signal, though, was far from ideal. It was not a very accurate repre- sentation of the original. Figure 7 shows how each step of the digitized waveform represents a change in level of six decibels (for a total dynamic range of 96 dB — sixteen steps multi- plied by six decibels). For mid- and high-level signals that does not pres- ent much of a problem. At very low levels, though, way down at the level of the least-significant bit, thesix-dB- per-bit assignment becomes very sig- nificant. That first step is a lulu — there's quite a difference between the total silence of zero dB and the sound level, low as it is, at the level repre- mum sampling rate must be twice the highest frequency to be sampled, also implies that if that rule is followed, all the information contained in the origi- nal analog waveform will be repre- sented in the digital samples. It's then simply a matter of knowing how to extract it. Today's digital filters have begun to do just that, and from the 8-bit (actu- ally 14-bit) signal stored on a CD it is now easily possible to extract a con- siderably more accurate 18-bit one. A few players go so far as to generate a 45-bit digital signal! The extra bits represent additional points on the rec- onstructed waveform (Fig. 8), and give a closer approximation to the original analog signal as well as re- quiring less analog filtering. The re- sult is, as President Bush might put it, a "kinder, gentler" waveform — one that docs not require as brutal an ana- log filter. The additional data points also make it possible to perform (within the digital filter, again) a pro- cess called noise shaping, which re- duces greatly the effects of a phenomenon known as quantization error, which is heard as noise. Just prior to the analog output filter is the circuitry that performs the digi- tal-to-analog, or D-to-A conversion. A manufacturer can choose to operate on any number of the bits generated by the digital filter, but generally re- stricts the number to 18. An 18-bit Digital-to-^nalog Converter (DAC) is about as good as current manufactur- ing processes can produce at a reason- able cost. Some players advertise "dual D-to-A converters." Using two DAC's means that each has to work less and is not being pushed to the limit of its performance; according to some it also adds extra separation be- tween channels. One-bit, 256 x oversampling This year you will begin to see CD players that offer 256 x oversam- pling. That's a frequency of 11.2896 MHz, for those readers without their calculators handy, with one-bit ac- curacy! 'All right," you say, "what happened to all the other bits?" And how can just a single bit tell you any- thing at all about how a piece of music sounds? The answer depends on how you understand the technique. In the MASH (multi-stage noise-shaping) system patented by Japan's NTT, and in another similar one developed by Philips, all the bits recorded on the disc are used but, rather than being reorganized as they come off the disc into 16-bit words, they are considered as a stream of bits, one bit at a time. (There is a good analogy to be made with parallel and serial communica- tions in personal -computer systems.) The very high sampling rate ensures accuracy and smoothness, and is the equivalent of sampling each bit of the 16-bit word 16 times. Further accuracy is claimed to be due to the use of a di fferent D-to-A conversion system than is found on conventional players. Traditionally, conversion of digital signals to analog form has been done using comparator networks weighted with resistors to give a stepped -wave form output of the sort described earlier. As the bits come off the line (as it were) in the 52 \SUBCOOES 5.4% SVNCHRONlZATh 4-- FIG. 10— ONLY ONE-THIRD of a CD's capacity is used to store digitized sound. Much of the rest contains error-correction information, and a substantial portion is devoted to the subcodes that make up a CD + G disc's visual content. . FIG. 11— THE FIRST CD + G/M PLAYER on the market is JVC's XL-G512. It decodes information contained in a CD + G disc's subcodes to output a video signal, and can also output MIDI control information for MIDI-equipped instruments and computers if that information is included on the disc. FIG. 12— -A CLASSICAL CD + G DISC might contain not only the performance and a copy of the score, but a commentary on the composition as well. Philips system, they are used to charge small capacitors. It is those charges that form the player's output waveform. An example of that PDM (Pulse Density Modulation) output is shown in Fig. 9. Philips claims great- er accuracy for its system compared to the resistor-comparator method. It, too, is "kinder and gentler."' CD + G/M There's lots more stored on the sur- face of a compact disc than just mu- sic. In fact, only about a third of the information there represents sound; the rest is used for error correction, indexing, and other purposes (see Fig. 10). A sizable chunk of space is reserved for the information known as subcodes. Until now, the subcode area has been pretty much ignored. Aside from a few CD players that had subcode outputs (the output of the digital subcode information, what- ever it might be), there were no sub- code standards to follow and, consequently, nobody did anything. However, an industry document known as the Sony-Philips Red Book has now set forth such standards for the industry, and the result is a new type of CD, known as the CD+G, or sometimes CD + G/M. Players for that new format are just becoming available, the first beina JVC's XL- G5I2BK shown in Kg. 11. The term "CD + G" stands for "Compact Disc Plus Graphics." The graphics are stored, in digital form, in the subcode area of a disc. They are decoded by a CD + G player and con- verted into a video signal that can be fed to a monitor or TV receiver. The video, while it cannot present any- thing like real-time-TV detail or ani- mation, docs have the appearance of a high-quality teletext signal. One application of CD + G is to have the subcoded graphics informa- tion accompany popular music as a form of music video. One of the first releases in that form is Donna Sum- mer's Another Place and Time. For classical music, the system can be used to display scores and librettos, and can even provide an on-screen commentary on the composition (Fig. 12). As the system becomes popu- larized, new uses will no doubt be found for it. In the meantime, CD + G discs can be played on ordinary CD players — you just won't see the "G" part. continued on page 56 > z c > < m a 53 ^™WqMZ flectrostotic Discharge Fight ESD and keep your components healthy. DAVE HOLLANDER CONSIDER THIS SCENARIO: YOU'VE RE- ceived a MOS IC, removed it from its black foam or pink foam packing, and soldered it in place. Your project might work initially, but its perfor- mance falls far below expectations. Your IC is probably a victim of elec- trostatic discharge (ESD), and was likely damaged by improper turn dling. ESD is one of the most com- mon causes of component failure, and as the actual transistor- device geome- tries on board a silicon chip shrink, an IC becomes more sensitive to it. ESD can cause component failure or performance degradation that's dif- ficult or impossible to detect, and is a major concern in modern electronics. The problems of ESD can occur as erroneous data, incorrect instruc- tions, or system shutdown on operat- ing hardware. This article will attempt to explain the mechanisms behind IC failure due to ESD, how to handle sensitive IC's properly, and how to set up a safe work area. How ESD is generated ESD is also calied triboelectric charging. When two insulators are rubbed together, charge is transferred by friction, like what occurs if you run your feet across a carpet. The charge is a function of separation, extent of contact, rate of separation, humidity, and, of course, the trib- oelectric material itself (see Fig. I). ESD current is pretty low, while potential can exceed 300 kV. When charge is built up in a human body and discharges as a perceptible arc AIR i HUMAN SKIM INCREASINGLY POSITIVE GLASS HUMAN HAIR WOOL FUR PAPER WOOD HARD ROBBER ACETATE RAYON POLYESTER PQLYURETHANE P01YVINYLCHICRIDE IPVCI INCREASINGLY NEGATIVE TEFLON r FIG. 1— THIS DEPICTION SHOWS the rela- tive propensity of different common mate- rials to either lose ("INCREASINGLY POSITIVE") or accumulate ("IN- CREASINGLY NEGATIVE") charge. (felt as a slight tingle), no damage is done if the potential is under 2.5 kV (the "discomfort threshold"). Levels below that are barely noticeable, but TABLE 1— SUSCEPTIBILITY TO ESD DEVICE RANGE OF ESD TYPE SUSCEPT- IBILITY, kV Power MOSFET 0.1-0.2 JFET 0.14-10 CMOS 0.25-2 Schottky Diodes, TTL 0.3-2.5 Bipolar Transistors 0.38-7 ECL 0.5 SCR 0.68-1 can disrupt equipment. Table I shows the relative susceptibility of various semiconductor devices to ESD. You might notice that you get elec- trostatic shocks more often in the winter than in the summer. That's be- cause, in the summer, the relative hu- midity levels are much higher, and the buildup of moisture on a surface pro- vides a discharge path. By com- parison, materials that reject moisture exhibit the highest propensity toward ESD. Above 65% relative humidity, there's no real ESD problem, while below 20%, over 300 times more stat- ic charge is generated. How much charge a human body will accumulate is dependent upon on the individual's size and skin con- ductivity. Another example of re- duced humidity giving rise to electrostatic charging and ESD oc- curs when you put nylon and poly- ester clothing together in a dryer. You've no doubt seen how you can often generate as much as 650 volts by doing so, since the primary object in a dryer is the removal of moisture, and the combination of nylon and poly- ester are prime triboelectric mate- rials. Typical ESD voltages are given in Table 2, for a number of common configurations. ESD and MOS IC's All MOS devices have an insulated gate that's subject to voltage break- down. The gates on Motorola's de- vices are about 800 angstroms thick, and they break down at a gate-source potential (V GS ) of about 1 00 volts. 54 The high-impedance gates are pro- tected by onboard resistor-diode net- works, but they don't make an IC immune to ESD. Laboratory tests in- dicate that devices can fail after one very high voltage discharge, or after the cumulative effect of several lower potential discharges. ESD-damaged devices behave in various ways. The most severely damaged devices are easiest to detect because their inputs or outputs have been completely destroyed; they're ei- ther shorted to V DD or V ss , or are open, and the device no longer func- tions. In other cases, detection can be more diflicult because the device is intermittent or degraded. From the data in Fig. I and Table 2, you can easily see why MOS IC's can be damaged by improper handling. ESD and Power MOSFET's Being MOS devices, TMOS™ transistors (Motorola's trade name for its power MOSFET's) can also be damaged by ESD. However, they're not as susceptible as CMOS, due to large input capacitances that let them absorb more energy before breaking down . However, at breakdown poten- tial, there's enough energy in the C GS to totally perforate the gate-oxide. With a typical V GS maximum rating of ± 20 volts DC, and ESD potentials typically reaching 100 volts-25 kV, TABLE 2— TYPICAL ELECTROSTATIC VOLTAGES MEANS OF STATIC GENERATION ELECTROSTATIC VOLTAGES, kV RELATIVE HUMIDITY 10-20% 65-90% Walking across carpet 35 1.5 Walking across vinyl floor 12 0.25 Worker at bench 6 0.1 Vinyl envelope 7 0.6 Common polyethylene bag picked up from bench 20 1.2 Work chair padded with polyurethane foam 18 1.5 you can see why special handling is needed. Curve-tracer plots of a MOS device before and after ESD degradation are shown in Figs. 2-ti and b. Where most power MOSFET's have the ±20-volt DC rating, Motorola power MOSFET's use the Butlet-Proof4TM process, resulting in more reliable de- vices with higher V GS breakdown lev- els. They're guaranteed to withstand ±40 volts DC for a single, non-re- petitive pulse of 50-p.s duration or less, achieved by control of gate-ox- ide thickness. With improved di- electric strength comes better resis- tance to ESD damage. Classification of devices Military specifications are used to classify ESD sensitivity of semicon- ductor devices. Through measure- ments, the model of Fig. 3 closely approximates the human body. Dis- charge of that network directly into a device indicates that the model as- sumes that a "hard ground" is in con- tact with the part. Although all pin combinations should be evaluated (six different versions for a power MOSFET), preliminary tests usually show that gate-oxide breakdown is most likely, and that reverse-bias makes a junction about an order of magnitude more sensitive than for- ward-bias. The damage mechanism is usually gate-oxide punch-through or junction melt-through. In other words, when a semiconductor device is subjected to unusually high volt- ages, the charges (holes and elec- trons) move apart in directions that they were never intended to go. Static protection The basic method for ESD protec- tion combines prevention of static build- up and removal of existing charge. Charge-dissipation pro- cedures differ for insulators and con- ductors. Since charge can't flow through an insulator, it has to be re- moved by contact with a conductor. If the item is an insulator (plastic box, clothing, etc.), ionized air is required. If it's a conductor (metal tray, con- ductive bag, person's body, etc.), complete discharge can be accom- plished by grounding. Many methods are used to inhibit 10 < 9 -I 8 £ 1 oz b = 5 < 3 2= 7 J> 1 u 20 40 60 B0 10D 120 140 160 180 200 V DS - VOLTS a 20 40 60 80 100 120 140 160 180 200 V DS - VOLTS b FIG.2— CURVE TRACER PLOTS OF A MOS device before (a) and after (b) being subjected to ESD degradation. ESD; carpets are made with antistatic materials and coatings. Equipment can be sprayed with antistatic solu- tions, materials with low triboelectric propensity can be used, and clothing can be made of triboelectrically in- sensitive fabric. Static-safe work sta- tions are also used. Components are packaged in conductive or antistatic packaging. In addition, relative hu- midity within the environment is maintained above 65%. How to prevent ESD? You might find industrial -grade precautions impractical, but if you're educated in ESD and its effects, you'll have better control of your FIG. 3— THIS MODEL CLOSELY approxi- mates the human body. Discharge of this network directly into a device indicates that the model assumes a "hard ground" is in contact with the part. > z c > < O 55 STATIC NEUTRALIZER GROUND STRAP R •1MEG FIG. 4— A TYPICAL ESD-PROTECTED WORK STATION, with a Me-inch metallic bench top, conductive floor mats and containers, ionized air blowers, wrist straps, and soldering- iron ground. Place all MOS devices on a grounded bench prior to handling. CD PLAYERS continued from page 53 working environment. A typical work station is shown in Fig. 4. Tlie steps to a ATTENTION __ ^^ ©Til TIP SENSITIVE DEVICE p "t JitAd I H I IU SAFE PACKAGING \*S MO^& AND HANDLING REQUIRED FIG. 5— ALWAYS USE PACKAGING labels like this one to indicate ESD-sensitive parts, and that proper handling ol the parts is required. be taken are listed below: • Never exceed maximum specified data-sheet ratings. • Work benches should have grounded metallic tops, conductive floor mats and containers, and ionized air blowers. • Use wrist straps in contact with the skin. • Use a ground strap on the tip of all soldering irons. • Place all MOS devices on a grounded bench prior to handling, since they can be statically charged with regard to the surface of a bench . • Never use brush or spray cleaning to remove solder flux from a MOS- g populated PC board with the IC's in- z stalled. If you want to clean such a PC £ board in this way prior to installing o the IC's, fine. gj • Place completed PC-board assem- o blies in antistatic bags if they're trans- 5 ported to another location. cc • Keep work benches free of coffee cups and stirrers, paper, styrofoam, tobaceo ash, cellophane wrappers, and plastic. • Never insert or remove an IC from its socket with power applied. • Check all power supplies for volt- age transients like ripple or spikes. • All low-impedance equipment like pulse generators should be connected to MOS devices only after power up. and disconnected before being shut off. MOS-device packaging is critical; components purchased for home proj- ects should come with antistatic or conductive packaging. Static-sen- sitive IC's are normally packaged in either black conductive foam, spe- cially treated pink plastic bags, or an oily antistatic styrofoam. There should also be packaging labels indi- cating ESD-sensitive parts, and that proper handling is required, as in Fig. 5, Never insert a MOS device into a conventional plastic tray or piece of styrofoam. Keep it in its original packaging until ready to use. All equipment should have a good earth ground, but particularly if it's ESD-sensitive. In a dry climate, at- tach a small metal plate with a good ground to your desk/workbench. By touching it to discharge any static po- tential built up while walking across carpeting, your equipment might live longer. R-E The "M" in "CD + G/M" stands for "MIDI," which itself is an acro- nym for "Musical Instrument Digital /nteiface." A MIDI signal is used to store or transmit performance infor- mation, such as the output of a music synthesizer's keyboard, which might consist of duration, pressure, and (of course) which- keys-are-pressed data as well as that for other performance parameters. You could use the MIDI signal to have your MIDI-equipped instrument play along. Gizmos, gadgets and gimmicks As you browse (or plow, depending on the intensity of your interest) through the literature on the new CD players, you'll come across mention of lots of special features that may tickle your fancy. Many of those fea- tures are intended to appeal to the high-end audiophile, and their effect on the quality of the final product (the sound that comes out of your speak- ers) may be so slight as to be un- noticeable to ordinary people. Some players use a single-beam tracking system while others boast of a three-beam one. Both use the inten- sity of the laser light reflected from a disc to provide control information that keeps the beam on track. Don't let the terminology confuse you. A three-beam system does not use three lasers; it just splits the output of a single laser into three beams. Indeed, all CD players contain just one laser whose beam is used both for reading the digital information from a disc and for tracking. A three-beam sys- tem can react more quickly to a "drift" situation, but you probably won't notice the difference. One or two makes of CD players boast a speed stabilizer that sup- posedly makes a disc rotate at a more even speed than it otherwise would. That feature is similar in purpose to the stick-on stabilizer rings that are sold separately to be attached to the outer perimeter of CD's to add to their mass (and presumably speed sta- bility). In either manifestation, that may not be such a great idea. First of all, the speed of a CD is constantly changing anyway, from 500 rpm down, as the laser beam tracks farther from the center of the continued on page 99 56 1989 ANNUAL INDEX Electronics Volume 60 and ComputerDicest Vo I u m e 6 Abbreviations: (AR)Antique Radio; (ARE)Ask R-E; (AUD)Audio Update; (C)Construction; (CD)ComputerDigest; (CC)Communications Corner; (D)Department; (DB)Drawing Board; (ED)Editorial; (EW)Editor's Workbench; (ER)Equipment Reports; (HH)Hardware Hacker; (HWR)Hardware Review; (LTR)Letter; (NI)New Ideas; (PCS)PC Service; (SR)Shortwave Radio; (SWR)Software Review; (VN)VideoNews Mar 25 Jan 34 Jun 67 Affi Swilch. Remote(Heil)(C) AC power-load interfacef Lancaster) (HH) A/D converters accuracy! Lancaster)(H H ) (LancasierJ(HH) Ace Communications AOR AR-2515 Communications Receiver(ER) Nov 24 ActiveAnlenna(Kreuter)(C) Feb 51 ,( PCS) Feb 110 {LTR)Apr 14, Jun 14, Sep 14 Alarm system High-Tech Home Security(Friedman) Apr 33 Install a Home-Security System{ Fried man & Fenton) Apr 42 Phasor Pmperty Guard (lannini) (C) Dec 37,(PCS)Dec79 Wireless Security Syslem[Becker)(C) Apr 47 All About Capacitors(Bernard) May 49 t Aug 56 Relays (Trietley) Nov 59, Dec 59 AlphaiTheta Meditation Goggles) Wo riey)(C) Apr 53,(PCS)Apr 59 (LTR)May 15,(LTR)Oct 14 Alternate dimming circuit(ARE) Sep S AM receiver Canter Current Receiver(Sheels & Graf)(C) Feb 55 Amateur TV Transmitter) Graf & Shee!s)(C) Jun 45, Jul 45 (PCS)Jul 56,84,(LTR)Sep 14 American Reliance AR-6400P Cable Tester(ER) Feb 22 Amplifier damping factor: How important is il?(Klein)(AUD) High-Power Hi-Fi Audio Amp for your Home or Car I Ross & Watls)(C) Importance ol amplifier output current, The(Klein)(AUD) Apr 70 Antenna Active(Kreuter)(C) Feb 51 Choosing the Right Shortwave Antenna(Carr) Jul 61 ANTIQUE RADIO (D)( Fitch) Jan 84, Feb 91, Apr 14, May 74 Condensers and tubes Jan 84,{LTR)Mar 14,(LTR)Apr 14 How television got its star! May 74 Loudspeakers and things Feb 91 April Fool's Macrowave oven(Hakemachi)(C) Apr 74 Mass- lei eportation card(Lancaster)(HH) Apr 25 ASK R-E(D) Ja n 12, Feb 12, Mar 8, Apr 8 May 12,Jun 12,(LTR)Sep 14,Jul 10 Aug 8, Sep B, Oct a Nov 12, Dec 8 Alternate dimming circuit Sep fl Broken IC pin Dec fl Computer-monitor color remover Delay circuit Digital Meiers Feb 12 TV AugB Flasher circuit Nov 12 Flashing LED's May 12 Gu i tar eq ualizer J un 1 2 LEDFIastier, sequential May12 Lig hi -control circuit Sep 8 Linear-to-Eog converter JuMO Mike Input Attenuator Dec8 Neon indicators Oct 8 PAL/SECAM conversions Jun 12 Parts valu es Octfl,(LTR)Dec14 Power Supplies Jan 12 Jan 78 Mar 51 Oct 8 JuMO Pulse shonener Jun 12 RAM increase Aprfl RFI solutions Mar 8,(LTR)Aug 12 Re-wiring homes Robot. Timex Nov 12 Mar 8 SCR, light-activated Jan 12 Septic pump automatic Nov 12 640K expansion Sep 8 640K rejeclion Sep B Telephone-cell recorder Oct 8 Time-base coneclor Feb 12 Timex robot Mare Touch switch TV Earphone jack May 12 Apr 8,{LTR)Jun 14 Interference Mare Z-80 Hardware Jan 12, Mar 8 Alan ST, The(Yap)(CD) Feb 99 AUDIOfSee also AUDIO UPDATE, SHORTWAVE RADIO) Amp, High-Power Hi-FKRoss & Watts)[C) Mar 51,(PCS)Mar 74 Beyond Stereo(Feldman) Sep 51 Carrier Current ReceivertSheets & Grat)(C) Feb 55 Transmilter(Sheets & Gral)(C) Jan 55 FMX: Is il Good lor FM?(Feldman) Oct 52 One-Band Shortwave Converter(Gra( & Sheets) (C) Oct 49 Tunable preselectors(Friedman)(CC) Jan 82 Video CD's(Lachenbruch) (VN) Dec 6 Wireless FM Microphone(Spiwak)(C) Mar 43 AUDIO LIPDATE(D)(Klein) Jan 78,Feb B9,Mar 84, Apr 70, May 70. Jun 87, Jul B,Aug 12,Sep 70, Oct 61,Nov 74,Dec 67 Amplifier damping (actor: How important is it? Jan 76 Evolution of car stereo, Ihe Sep 70 Frequency response: What do the numbers ready mean? Aug 71 Happy 10th Anniversary, Sony Walkman Oct 72 History and theory of the dynamic loudspeaker May 70.{LTR)Aug 12 How loud is real' Jul B HX-Pro: A "new" and improved cassette-deck circuit Mar 84 Importance of amplifier output cunent. The Apr 70 Queslion of reliability, the Feb 89 Slew factor. How Important is il? Jun 87 Sonic Differences Between CD Players? Dec 67 Sound of CD. Part 1 Nov 74 Automatic Test Equipment! Stover) Oct 61 AVCOM PSA-65A Spectrum Analyier(ER) Nov 24 B B&K- Precision 1201SR Television Frequency Converier,'Modulator( E R ) 1249 NTSC Generator(ER) 388-HD Test Bench(ER) Basic Op-Amps (Marston) Bar-code resources(Lancaster)(HH) Battery Backup REACTS(Bybee)(C) Battery-charge indicator! LTR) Oct 17 Dec 18 Mar lii Mar 59 Jul 66 Jan 65 Aug 12 Beckman Industrial Model 233 Professional Digital Multimeler(ER) Aug 16 Beyond Stereo(Feldman) Sep 51 Bilateral Switches(Marston) Nov 54 Brain waves AlphaTheta Meditation Goggles[Worley)(C) Apr S3 Broadcaster, wireless sfereo(Lancasier|(HH) Oct 65 Bug Delector(Ross)(C) Jun 42,(PCS)Jun 78 Build This (See CONSTRUCTION) Building an OmniView Applrcation(Toutonghi)(CD) Aug 80 Business, starting a technical (Lancaster)(HH) Jun 67 CD (See COMPACT DISC) CMOS oscillators(Lancaster)(HH) Jul 66 CMOS PLL's(Marston) Dec 55 Cable -converter "hum"(LTR) Feb 14 American Reliance AR-6400P(ER) Feb 22 for Only $25 , Build a(Barbarel lo)(CQ)(C ) Apr77 (Rowe)[NI) Mar 73 Calibration 10-MHz Frequency Slandard(Palmer)(C) Feb 63 Call progress delectors(Lancasler)(HH) May 61 Canon FAX-L920 Laser Facsimile(ER) Feb 22 C n p Lie i t s ri re- Inductance Meter, Sencore LC102IER) Apr 17 Meter, Dig ital ( Lashansky)(C) J ul 38,(LTR)Oct 1 4 Capacitors. All Abou [(Bernard ] May 19. Aug 56 Car stereo Evolution of(Klein)(AUD| Sep 70 High- Power Hi-Fi Audio Amp for your Home or Car(Ross & Watls)(C) Mar 51 One- Band Shortwave ConverterfGraf & Sheets)(C) Oct 49 Carrier Current Audio Transmit ter(Sheels & Graf)(C) Jan 55 Receiver(Sheets & Graf)(C) Feb 55 CeBIT(Endrijonas)(CD) Jul 73 Character generator Complete Circuit, A(Grossblalt)(DB) Jul 28 Custom(Grossblatl)JDB) Mar 80 Let's slarl prog ra mming I (Grossblatt)( DB ) May72 Choosing the Right Shortwave Antenna(Carr) Jul 61 Video Tape That's Right for You ( Feld man) May 45 Circuilmate DM27 Digital Multimeler(ER) Oct 17 CIRCUITS(See also ASK R-E, DRAWING BOARD) Basic Op-Amps(Marslon) Mar 69 Bilateral Swilches(Marston) Nov 54 CMOS PLLs(Marston) Dec 55 Compound Op-Amps(Marsfon) Jan 69 Down -Counter Cookbook! Marston) Feb 71 Op-Amp OscillatorS(MarstOn) Jul 51 Op-Amps in Instrumentalion(Marston) Sep 59 Relays. All AboutfTrietley) Nov 59,Dec 59 Working With Countersf Marston) Apr 63 Op-Amps( Marston) May 54 Clock and doorbell chip(Lancaster) (HH) Dec 68 Cold fusion (Lancaslerl(HH) Aug 64, Sep 65 (LTR)Aug 12 c > 31 -< 57 more onl Lancaster |{HH) Nov 64 Comdex, Report From(CD)(EW) Aug 75 CO M MU Nl C ATIONS C ORN EFtl D)( Fr I ed m a n ) Tunable preselectors Jan 82 COMMUNICATIONS! S«e also COMMUNICATIONS CORNER) Fax-Mafe(F1ant)(C) Oct 33 ISDN Prototyping Telephone (Tousignant & Sllger)(C) May 35, Jun 61 Ughl Beam Commumcator(Sonnlag)(C) Jul 31, Aug 52 Phonlink 1 1 ( MeNabb & Rosath ) Feb 44,Mar 46 Command Post, Wilson WindowWare(SWR ) ( E W)(C D) Communications Receiver Ace Communications AR-2515(ER) Communicator. Light BeamlSonntagJlC] Compact disc Audio video !Lachenbruch)(VN) Players. How lo Repair) Phelps) the sound of CD. Pari HKleinl(AUO) the sound of CD. Part 2(Klein)(AUD) Compass Digi-CompasslBiack)[C) Complete Circuit, A(Grossblalt)tDB) Compound Op-Amps(Marston) COMPUTER(See also COMPUTER DIGEST, DRAWING BOARD) -Aided Video(Morlon & Scott] (CD) Mar 93(LTR)Jun 14,0et 14 Digi-Compass(Black)(C) Interface Automatic Test EquipmentfStowrJ Radiation Monitor UpdaleiJalfe S. Sythe) Monitor color reinover(ARE) Musical Instrument Digital IntenacefSimonton) Phonlink H(MeNabb & Roselh).(C) REACTS(6ybee)(C) Mar B,(LTR)MAug 12 Sep 8 Jan B7,Feb 95. Mar 39. Apr 77 May 77,Jun 79,Jul 73,Aug 75 Sep r 7. Oct S3. Nov 83, Dec 81 Feb 99 w o ■z. o rx r- o Lii o Q < or Dec 81 Nov 24 Jul 31 .Aug 52 Dec 6 Nov 52 Nov 74 Dec 67 Nov 43 Jul 28 Jan 69 Nov 43 RFI solutions! ARE) 640K Rejection! ARE I COMPUTER DIGEST Oct 61 Jon 51 Oct 8 Aug 33 Feb 44 Jen 65 Aug SO Jul 73 r 93,{LTR)Jun 14. Oct 14 May 77 Atari ST, The(Yap) Building an OmnlView Appl ication ( Toutonghi 1 CeBIT(Endrijonas) Computer Aided Video (Morion & Scotl) Digital to Analog Converter(Weber)fd) EDITOR'S WORKBENCHfD) (Holtzman) Jan BB.Feb 96,Mar 90,Apr 77 May 77. Jun 79,Jul S3.Aug 75 Sep 77, Oct S3.Nov 81.Dec 81 Book reviews Feb 96.Mar90.Apr 77 Jul 75, Aug 75,Sep 77.0et 83 Bolt Systems MultibooUSW ) Oct 83 Borland's Turbo Pascal S.OISWR) Mar 90 Button Wares PC-File:dB(SWR) Aug 75 Cambridge Directs Z88 laptop(HWR) Feb 96 Comdex. Report From Aug 75 0-G Electronic Developments' DoubleCOM(HWR) Datastorm Technologies' ProComm + (SWR) DG Electronic Developments DoubleCOM(SWR) Dot programs Hayes Microcomputer Products' SmarlCom lll(SWR) Inset Systems' Hijack(SWR) IQ Technologies' Smart RS-232 Data Meter(HWR) Laptops Laser-pnnter paper Mace's Gofd(SWR) Micrcgralx' Designer(SWR| htorton Utilites Advanced Edition Version 4.5ISWR) OS 2 Presentation Manager(SWR) Standard Edition Version 1 1(SWR) Prime Solution's Disk Technidan(SWR) RG Software Systems' Disk Watcher! SWR) Tandy Model 100 laptop(KWR) Telelek X Bandit EMS 4.0 Memory Board (HWR) Toshiba T1000 laptop(HWR) Traveling Software's Lapiink(SWR) ViewLink(SWR) Turbo Pascal S.OISWR) Wilson WindowWares Comand PosKSWR) Windows, MicrosoflfSWR) 80386 Motherboard(Mcl!hany)(C) Jun 79,Jul 81,Aug 75 Install a Tape Backup Unil, How tO(FentOn) Jun 79 Inside Intel's 80386 (Margufis) Jan 90. Feb 103, Mar 98 Intelligent Cable Tester for Only S25'(Barbarello)(C) Omniview and a 386!Toutonghi) PC Run Circles Around a Cray?. A(Byersi Programmable Architectures: The Nexl Breakthraugri?(Reeve| Put a 386SX Tiger in Your Tank(Mcilhany) (C ) J u n 79 . J u ! S 1 . A u g 7 S Run MS-DOS on the PT-68K(Henry)(C) Jan 96 68705 Microcontroller (Henry)(C) Sep 82,Oct 83 Condensers and tubes(Filch)(AR) Jan 84 CONSTRUCTION Active Antenna! Kreuler] Feb 51 Jan 88 Jan 88 Oct S3 Mar 90 Jan 38 May 77 Mar 90 Feb 96 Aug 75 Jul 75 Mar 90 Jul 75 Apr 77 Apr 77 May 77 May 77 Feb 96 Jun 79 Feb 96 Sep 77 Jun 79 May 77 Dec 81 Dec 81 Apr 77 Jul 73 Apr 77 Sep 77 AIphaTheta Meditation Goggles! Worley) Amateur TV Transmitter (Graf S, Sheets) Bog Detecior(Ross) Carrier Current Audio TransmilterfSheets & Graf) Receiver(Sheets & Graf) Dlgi-Compass( Black) Digital Capacitance Meter(Lashansky) Peak DetectorlSecuraj Apr 59 -lo Analog Converter(Weber)(CD) May 77 80336 Motherboard (Mc I Ihany}! CD) Jun 79. Jul 81. Aug 75 Etching Tank(Lewis) Dec 45 Fax-Mate(Planl) Oct 33 High-Power Hi-Fi Audio Amp for your Home or Car(Ross S Watts) Mar 51 ISDN Prototyping Telephone tTousignant « Sligcr) May 35,Jun 61 Intelligent Cable Tester for Only $251(BarbarellO)(CD) Apr 77 Light Beam Communlcatar(Sonntag) Jul 31,Aug 52 Low Frequency Converler(Sheels & Graf) Transmitter! Nelson ) Low-Capacitance Scope Probe(Frredman) Macrowave Oven(Hakemachi) Music-On-Hold Adapter(Sokolowski) One- Band Shortwave Converter! Graf & Sheets) Phasor Property Guard(lannini) Phonlink IKMcNabb & Roseth) Plasma Display Globe(Caudill) Pul a 386SX Tiger in Your Tank! Mel lhany)(CD) R-C Decade Box(Lashanskyl REACTS(Bybee) RGB-to-NTSC Converter (Bek)(CD) Remote A'B Switch (Heil) ■Custom" EPROM decoders Jan 80 Apr 53 Complete Circuit. A Jul 28 Contest is over, the Sep 72 Jun 45. Jul 45 Custom-character generator, A Mar 80 Jun 42 Developing and Etchrng a PC Board Dec 77 Laying out a PC BoardfGrossblatt) Oct 81 Jan 55 Lets slart programmingt(Grossblatt) May 72 Feb 55 PC boards(Grossblatt) Aug 73 Nov 43 PC Photography Dynamic loudspeaker, history and Nov 78 Jul 38 Itieory of (Klein)! AUD) May 70 Sep 47 Sep 43 Jan 52 Apr 74 Aug 42 Oct 49 Dec 37 Feb 44, Mar 46 Jan 62 Jun 79, Jul 81, Aug 75 Nov 39 Jan 65 Dec 81 Oct 37 Remote Control Exle nd er( H ei I ) May 41 Run MS-DOS on Ihe PT-6SK(Henry)(CD) Jan 96 66705 Microcomrolter(Henry)(CD) Sep 82. Oct 83 Solar Power Supply (Becker j Aug 47 Spectrum Analyzer(Baumgartner) Sep 33 Monitor! Baumgartner) Oct 46 1 ■ M H z Frequency Slandard( Palmer) Feb 63 Universal Laser Power Supply(McComb) Mar 33 Video Scene Switcher(Srieet5 & Graf) Nov 33, Dec 42 Wireless FM Microphone!Spiwak) Mar 43 Wireless Security System (Becker) Apr 47 Contest is over, ihe(Grossblatt)(OB] Sep 72 Converter Digiial to Analog Convene rJWeberMC) May 77 Low FrequencytSheets &, Graf)(C) Sep 47 Coprocessor accelerator boardfByers)(CD) Apr 77 Counters. Working Wrlh(Marslon) Apr 63 Custom -character generator. A(Grossblatlj[DB) Mar SO "Custom" EPROM decoderslGrossblaril'DB) Jan 80 Data booxs(HH) Jan 34 Delay circuit(ARE) JuMO Oesigner. Microg rat x"(S WR) (C D) ( E W) Mar90 Designing PC boards[DB) Aug 73.0ct 31 Desktop book publishing! La ncaster)(HH) Sep 65 Detecior, bug(Ross)(C) Jun 42 Developing and Etching a PC Board(GroS5blatt)(DB) Dec 77 Dialog information service(Lancasterti'HHl Mar 25 Dlgi-Compass(BlacM(C) Nov 43 Digital Audiof'HH) Jul 66 Audio front ends(Lancaster)(HH) Jun 67 Capacitance Meter! Lastiansky)(C) Jul 38.(PCS)JUI 84 Compass Digi us u nil I circuit." Hardware Hacker PostScript fractal fern Unusual cooling ideas Thermoelectric modules Chaos science resources Superintelligent machines Chaos science resources DON LANCASTER LET S START OFF WITH SOME NEW Up- date info for our previous col- umns. The 38.4-kilohertz crystal needed for the stereo broadcaster is available for around $3 from Statek, who stocks quite a wide variety of small and cheap low-fre- quency crystals. Since 38.4 kHz is a standard modem value, it seems a better choice than your usual 38,0-kHz stereo-multiplex frequency, and should work just about as well. Probably your best way to throw the project together, though, is to go to one of the kits that are of- fered in the Radio-Electronics clas- sified section. One interesting use for that chip is to measure the torque on a rotat- ing shaft. A $1.50 part can easily replace a $1100 telemetry system here, at a lower power and smaller si/e. Two additional sources for heavy water (deuterium) are the Canadian Atomic Energy Commis- sion and their tsotech reps here in the US. Price is in the forty-cents- per-gram range. A key cold-fusion paper appears on pages 301-308 of Volume 261 of the Journal of Electroanalytical Chemistry. The EPRI journal (flec- tric Power Research /nstitute), Au- gust 1989, also has some interest- ing stuff in it. A few of you callers on our hacker helpline have suggested faking those high-priced linear ac- tuators we looked at two columns back. To do that, take an ordinary stepper and couple it to a piece of threaded rod by using shrink tub- ing. Then add two nuts and some sort of platform to create a travel- ing slider. Various tricks could eliminate backlash, and you should be able to replace a $57 list price actuator with a surplus $2 stepper. As per usual, all of our names and numbers have been gathered together for you intoone common sidebar. Thermoelectric coolers There sure appears to be a lot of hacker interest in the ther- moelectric cooling devices. We'll start off with the bottom line — be- sides their very high costs, those devices are pretty much useless, since they are so incredibly and horribly inefficient. They are only workable for very specialized and arcane applications where nothing else will do. Thermoelectric coolers will work only when you go to ridiculous extremes on in- sulation and heatsink efficiency, and then are capable of pumping only tiny amounts of heat. And, to further shatter some hacker dreams, no way will they make ice in the real world. At any rate, a thermoelectric module is a solid-state cooling de- vice. All you do is input a current, NEED HELP? Phone or write your Hardware Hacker questions to: Don Lancaster Synergetics Box 809- RE Thatcher, AZ. 85552 (602) 428-4073 and heat moves through the de- vice, cooling one side and heating the other. Figure 1 shows you a typical de- vice. That one's the Cambion model 801-2007. A similar compo- nent is also available through Melcor. That dude measures some two inches square and can move up to 22 watts of heat when powered by a 12-volt car battery at 7 amps. Cost is in the $20-$30 range. Solid-state cooling modules use the Peltier effect. Figure 2 shows you details. What you do is start off with bismuth telluride or some other semiconductor. Then you cut it up into blocks, while heavily p doping some of them and n dop- ing others. When a current is applied in the proper direction, the electron car- riers in the n material and the hole carriers in the p material will "drag" thermal energy along with their motions. In both cases, the heat moves downward, creating a hot side and a cold side. The amount of heat you do move depends highly upon the tem- perature differential you have to maintain. As Fig. 3 shows, that par- ticular device can provide a 60°C difference between the hot and cold side, provided that you pump no heat through it. On the other hand, if you do maintain both sides at the same temperature, you can pump up to 22 watts of heat c_ through the device. § In most uses, of course, you will > want both to cool something and < move heat, so you must use the £ middle of the curve. For instance, o 61 m o z o cc t5 UJ _i UJ 6 Q < NAMES AND NUMBERS FIG. 1— THERMOELECTRIC COOLING modules are fairly cheap and easy to ap- ply, but they are so inefficient that they are pretty much useless for any higher-power heat pumping. you could pump eight watts with a 40°C drop. To put that in perspec- tive, the module could, in theory, make a very small ice cube in around one hour.. .under ideal conditions. The trouble is that conditions are never ideal for thermoelectric modules. There are a number of nasty "gotchas" that will gang up on you when you try to use them in the real worid. Cambion 1601 N. Powerline Road Pompano Beach, FL 33069 (800) 274-6748 Canadian AEC 34 Slater Street Ottowa, Ont, CANADA KtA 0S4 (613) 237-3270 Computer Shopper One Park Avenue, 11th FL New York, NY 10016 (212) 503-3500 DATArx 111 E. Drake Road, Ste. 7041 Fort Collins, CO 80525 (303) 223-2120 Edmund Scientific 101 E. Glouchester Pike Barrington, NJ 08007 (609) 573-6250 Thermoelectric modules are rather expensive, mostly because they have not been improved one iota in the last two decades. Worse EPRI Journal Box 10412 Palo Alto, CA 94303 (415) 855-2370 Isotech 3858 Benner Road Miamisburg, OH 45342 (800) 448-9760 Haygeman Machine 2225 South 170th Street New Berlin, Wl 53151 (414) 797-7520 Lightwave Box 2139 Tulsa, OK 74101 (918) 835-3161 Mefcor 990 Spruce Street Trenton, NJ 08648 (609) 393-4178 yet, all of them are horribly ineffi- cient. In a typical use, you'd have to input five watts of input power to provide just one watt of cooling. cold r NEW FROM ^ DON LANCASTER HANDS-ON BOOKS Hardware Hacker Reprints II 24.50 Ask The Guru Reprints 1 or II 24.50 CMOS Cookbook 18.50 TTL Cookbook 16.50 Active Filter Cookbook 15.50 Micro Cookbook vol 1 or II 16.50 Enhancing your Apple 1 or II 17.50 AppleWrlter Cookbook 19.50 Apple Assembly Cookbook 21.50 Incredibte Secret Money Machine 10.50 LaserWriter Reference (Apple) 19.50 PostScript Cookbook (Adobe) 16.50 PostScript Ref. Man. (Adobe) 22.50 PostScript Prog. Design (Adobe) 22.50 Real World Postscript (Roth) 22.50 UNLOCKED SOFTWARE LaserWriter Corner (lle/Mac/PC) 29.50 PostScript Show & Tell 39.50 Intro to PostScript VHS Video 39.50 PostScript Perspective Draw 39.50 PostScript Beginner Stuff 39.50 PostScript Technical Illustrations 39.50 PostScript Work in Progress 39.50 PostScript BBS stuff 19.50 Absolute Reset lie & lie 19.50 AppleWriter/Laserwriter Utilities 49.50 Enhance 1 or II Companion Disk 19.50 AppleWrlter CB or Assy CB Disk 24.50 1 FREE VOICE HELPLINE VISA/MC SYNERGETICS ! Box 809-RE Thatcher, AZ 85552 I <602) 428-4073 j CIRCLE 83 ON FREE INFORMATION CARD Electron carriers in N material "tow" heat energy downward. (+>■ N Hole carriers in P material "low" heat energy downward. hot FIG. 2— A THERMOELECTRTIC MODULE consists of blocks of bismuth telluride that have been alternately n- and p-doped. The blocks are placed electrically in series and thermally in parallel. When a DC current is applied, electrons in the n material and holes in the p material will tow heat along with themselves. 20 - HEAT PUMPED IN WATTS 10 - r 1 r 20 40 TEMPERATURE DIFFERENCE IN DEGREES C. FIG. 3— THE AMOUNT OF HEAT PUMPED by a thermoelectric module depends on the temperature drop you require. Note that the heat transferred at the maxim urn temperature differential is zero. Note also that the heat differential is with respect to the hot end of your heat sink, and not to ambient. 62 NAMES AND NUMBERS Philips/Signetics 45 George Washington Hwy. Smithfield. RI 02917 (401) 232-0500 Sanyo 7 Pearl Court Allendale, NJ 07401 (201) 825-8080 SGS 1000 East Bell Road Phoenix, AZ 85022 (602) 867-6259 Sprague 70 Pembroke Road Concord, NH 03301 (603) 224-1961 Statek 512 North Main Street Orange, CA 92668 (714) 639-7810 Mechanical air conditioners are al- most fifty times more efficient than that! Worse yet, you have to apply that extra heat to exactly where you do not want it. The heatsink you connect the hot side of the module to must be absolutely flat, and be machined to within 0.001 inch over its entire area. It must then get carefully cov- ered with a thin layer of thermal grease. Obviously, those portions of a module not contacting the heatsink can not deliver any useful cooling. The real kilter of most ther- moelectric-module applications lies in the thermal drop between the heatsink and the ambient tem- perature. For higher power uses, a fan or water cooling is essential. For instance, a very large plain old heatsink will have at best a1°C- per-watt temperature rise above the ambient. Say you want to pump the 8 watts at a 40°C drop. The heatsink will have to sink those 8 watts, plus an additional 32 watts or so of input power for a total of 40 watts. At rC-per-watt heatsink rise, the heatsink will warm to 40°sC above the ambient room temperature. And you've done nothing but break even! The cooling module has a 40-degree drop across it. The heatsink has a 40-degree rise across it. And the net cooling is zero. You have nothing at all to show for all your effort. One more time: In the previous Stock Drive Products 2101 Jericho Turnpike New Hyde Park, NY 11040 (516) 328-3300 Synergetics Box 809 Thatcher, AZ 85552 (602) 428-4073 Tektronix Box 4600 M/S 94-860 Beaverton, OR 97076 (800) 426-2200 Texas Instruments Box 809066 Dallas, TX 75380 (800) 232-3200 Vortec 10125 Carver Road Cincinnati, OH 45242 (800) 441-7475 example, your final cooling is zero, because the hot side of the heatsink rises just as much above ambient as the amount of tem- perature drop you are trying to achieve! And a one-degree-per- watt heatsink is a darn good one. ..and large, too. So, an extremely low thermal drop from heatsink to ambient is absolutely essential. Also essential is an incredible quantity of insula- tion around whatever you are cooling, for any net heat flux into your area being cooled will only make matters much worse than they already are. The modules can get reversed by reversing the current. Because of the inefficiency, the heating mode is five times more effective than the cooling mode. One side effect of that ineffi- ciency is that you must run the modules off nearly pure direct cur- rent. The least amount of power- supply ripple will dramatically cut the cooling ability, since the ripple troughs will heat your load five times better than the ripple peaks will cool your load. A car battery is often the best choice to power your ther- moelectric modules. You might temporarily demonstrate a mod- ule by holding your module be- tween your thumb and finger and then connecting the module to a single alkaline "D" cell. Do not use the "D" cell for more than a few seconds at a time. What good are thermoelectric modules? You definitely can't buy a 4x8 foot panel of them and use them to air condition your house. But they are lots of fun to play with. They're a sure-fire topic for a winning science-fair project or student paper. Besides that, though, thermoelectric modules are limited to those specialized and low-load uses where nothing else can do the job. Important uses include coolers for infrared detectors, dew-point humidity sensors, chillers for microscope stages, and for thermal-manage- ment uses in satellites. I have often wondered why they are not used in satellite-receiver front ends. I guess the answer is that the gain of the input amplifier drops faster with temperature than the noise figure improves. Both Cambion and Melcor have lots of interesting tech literature on thermoelectrics, so you might want to contact both for more info. Other coolers There are three other ap- proaches to unusual cooling techniques that are hacker hacka- ble. You just might want to pick up on those instead. First, Japanese air conditioners are ridiculously better than the American ones, and have been for the past few years. It seems that all the American manufacturers re- fuse to pick up the new tech- nology, blaming the building codes, and claiming that a custom- er demand does not exist. The new air conditioners have EER's (Energy Ffficiency Ratings) approaching a value of 15, mean- ing that they use 33 percent less electrical energy than ours do. That's $60 per month or so. They are also much quieter and far more comfortable. Four of the secrets include a new beastie called a scroll compressor, a motor with an infinitely variable speed blower on the air handler, and a total pro- grammed microprocessor control. I guess you would call the sec- ond device a solid-state cooler, al- though you do need a large air L compressor across the room for a § power source. At least the extra > heat is not generated at precisely ^ the wrong place, as is the case with ^ thermoelectric modules. o 63 a O C£ t- O 111 LU O Q < It turns out that rapidly moving air accepts heat from slowly mov- ing air. Thermodynamics and all. So, if you build a suitable vortex nozzle device having one inlet for shop air and two outlets, you can arrange things so that cold air comes out one end and hot air out the other — with zero moving parts. Believe it or not, you can get as cold as the - 40°Fah re nheit dry- ice temperatures, or else you can optimize the flow rates to get max- imum heat pumping at tower tem- perature differentials. One obvious use for those is as needle coolers for industrial sew- ing machines. Any heat-caused needle breakage can be almost completely eliminated by using a vortex nozzle. The leading manufacturer of vortex cooling nozzles seems to be Vorfec. Besides offering bunches of free data and free au- dio-cassette tapes on vortex cool- ing, they also have a number of other unusual nozzles that can do such things as air amplification. As a third approach to effective cooling, dry-ice machines are amazingly low cost and simple. Edmund Scientific is one source. All you do is to connect the ma- chine to a carbon dioxide tank (also cheap) from your local gas supplier and turn it on. Slightly over half the gas expands and boils off, while the rest of it will cool and solidify into one solid block. Pres- to — instant cold. Naturally, you do that only in a well-vented area while you are wearing safety glasses. You also will want to avoid the instant frost- bite caused by roughly handling the finished product, or otherwise letting it come into skin or eye contact. Another contest In case you have not noticed, the bottom has once again fallen out of the memory-chip market, eliminating that insane two-year pricing blip that was directly caused by some incredibly stupid and monumentally misdirected government meddling in the free- trade process. Your jellybean 1- megabyte dynamic RAM chips can now be had in quantity for as little as $8 each. That translates to around 800 microcents per bit. FRACTAL AND CHAOS SCIENCE RESOURCES Beauty of Fractals, by Peitgen and Richter Earlier text that is both a coffee table book and a source of useful algorithms. From the same publisher that did the Science of Fractal im- ages. {Springer-Verlag, 1986) 175 Fifth Avenue, New York, NY 10010 (212) 460-1500 BYTE Magazine Occasional fractal articles and re- views. See A Better Way to Com- press Images, January 1988, pp. 215-223 in particular. 1 Phoenix Mill Lane, Peterborough. NH 03458 (603) 924-9281 Chaos — Making of a new Science, by James Gleick Interesting and easily read survey of the entire field of fractals and chaos science. Frustratingly shallow at times. (Viking, 1987) 40 West 23rd Street, New York, NY 10010 (212) 337-5200 Fractal Geometry of Nature, by B.B. Mandlebrot The original "horse's whatever" book that started it all. Mind-blowing artwork in an otherwise unreadable and excessively egocentric text. (W.H. Freeman Press, 1982) ■4419 West 1980 South, Salt Lake City, UT 84104 (801)973-4660 And hackers can once again re- joice. Yea team. Now, depending on who is doing the counting, the human brain will contain the equivalent of four billion memory bits or so. That's equal to a dozen CD-ROM platters or a small shoeboxfull of 1 Meg x 8 SIMM strips. It's also equal to a mere eight of the 64 Meg x 8 SIMM's just beginning to emerge from their preliminary lab research stage. Projecting these ongoing mem- ory trends, in around ten years or so, machines will definitely be smarter than people. So, for this month's contest, just write me a short essay on exactly what hap- pens when machines will inevita- bly become the most intelligent life form on earth. We 'I I have all the usual Incredible Secret Money Machine book prizes for the dozen or so best entries, with an all-expense- paid (FOB Thatcher, AZ) tinaja quest for two going to the top en- try of all. As usual, all entries have Science of Fractal Images, by M.K Barnsley et. al. Outstanding collection of useful hands-on fractal information. Good starting place to extend your own re- search. Includes algorithms and a good bibliography (Springer-Verlag, 1988) 175 Fifth Avenue, New York. NY 10010 (212)460-1500 SCIENCE Magazine Occasional fractal and chaos sci- ence articles and reviews. 1333 H Street NW, Washington, DC 20005 (202)326-6400 SCIENTIFIC AMERICAN magazine Occasional fractal articles and re- views. See their Computer Recrea- tions column for ongoing info and comments. 415 Madison Avenue, New York, NY 10017 (212)754-0550 SIGGRAPH Proceedings Far and away the best annual com- puter graphics show. Includes the latest and best of fractal and chaos science developments, on all three levels — theoretical, tutorial, and artsy-craftsy. (Siggraph-ACM Press, annually) 11 West 42nd Street, New York, NY 10036 (212)869-7440 to be on paper, and should get sent to me here at Synergetics, rather than to the editorial depart- ment of Radio-Electronics. Now, there's a memory effect that nobody talks about very much, and its implications for ma- chine intelligence are genuinely scary. I like to call it the threshold effect. Your threshold effect goes like this: If you double the size of a memory, the performance ca- pabilities of that memory usually will expand by much more than a factor of two. That happens be- cause the arrangement and the use of your memory can now be better organized, and can more effectively perform higher-level functions. For instance, some of your smallest microcontrollers only have room for a single hand-coded program. Add a little memory, and you can step up to a system monitor that gives you more power and control. More memory and you step up to some interpreted language. More still, 64 Plug a Friend into Radio-Electronics this Christmas ... and Save $11! This Christmas give an electrifying gift ... plug a friend into Radio-Electronics and brighten his whole new year! Whether electronics is his livelihood or his hobby, your gift will sharpen his focus and illuminate the whole spectrum of electronics throughout the coming year. Radio-Electronics will keep him informed and up-to-date with new ideas and innovations in all areas of electronic technology ... computers, video, radio, stereo, solid state technology, satellite TV, industrial and medical electronics, communications, robotics, and much, much more. He'll get great plans and printed circuit patterns for great electronic projects. In just the last year, Radio-Electronics has presented voice scramblers, video switchers, frequency standards, wireless audio links, radiation monitors, function generators, and much more. In coming issues, Radio-Electronics will present practical, educational, and money- saving projects like: a helium-neon laser ... a lighting controller ... a video timebase corrector ... a video noise processor ... a light-beam communicator ... an antenna amplifier ... and many others! PLUS . . . equipment troubleshooting techniques ... circuit design ... reports on new technology and new products . . . equipment test reports ... in-depth coverage on computers, video, audio, shortwave radio . . . and lots more exciting features and articles. SAVE $11 ...OR EVEN $22 ... For each gift of Radio-Electronics you give this Christmas, you save a full $11.00 off the newsstand price. And as an R-E gift donor, you're entitled to start or extend your own subscription at the same Special Holiday Gift Rate — you save an additional $11.00! No need to send money ... if you prefer, we'll hold the bill till January, 1990. But you must rush the attached Gift Certificate to us to allow time to process your order and send a handsome gift announcement card, signed with your name, in time for Christmas. So do it now . . . take just a moment to fill in the names of a friend or two and mail the Gift Certificate to us in its attached, postage- paid reply envelope. That's all it takes to plug your friends into a whole year of exciting projects and new ideas in Radio-Electronics! +$??*&Wf § 67 CO z o BE I- o HI _l LU o < DC and you pick up a sophisticated operating system. The next level gives you fancy toolboxes, and integrated programs. The level beyond that can give you powerful new levels of organizing the programs them- selves. HyperCard and its mutants are an obvious example here. Beyond that lies all the expert sys- tems, massively parallel architec- tures, and artificial intelligence. Because of the threshold effects, going from a 4-rnegabit memory to a4-gigabit one will gain you far more than a mere 1000:1 in performance abilities. I feel that something like a million to one is more like it. It would seem to me that there are probably three or four brand new and previously unrhought of thresholds that lie between where we are today and where we will be when we get up to routinely being human-brain sized a decade from now. What are the thresholds and when will they get crossed? Know- ing the correct answers to that one could make you filthy rich in a real hurry. Chaos and fractal resources There is a new endeavor out there that is known as Chaos Sci- ence. Actually, it's really a loosely knit collection of all sorts of un- usual old and new stuff, much of it only weakly related, if at all. As a general rule, if something can keep a math freak off the street at night and if it looks pretty in an alien sort of way, then it probably can be called chaos science. Since chaos science is futuristic, utterly and totally bizarre, and more than eminently hackable, it should be of foremost interest to most of you Radio-Electronics hackers. Our Chaos Science Resources sidebar will give you a quick sum- mary of a few of the main places to go for further info on this exciting new field. You'll probably want to start off with James Cleick's book Chaos — Making a New Science. It offers a thorough and easy-to-read but sometimes shallow introduc- tion to the field. The horse's whatever document on the subject, of course, is Man- dlebrot's Fractal Geometry of Nature. While more than pretty to look at, the text is pretty nigh un- readable and is both laughingly and pompously egocentric. The book I am currently the most impressed with is the new Science of Fractal Images, es- pecially in chapter five. A good summary appeared in the January 1988 Byte magazine and it was un- der the title A Better Way to Com- press Images. One of the things that struck me about that great book and the Byte summary article was that the sam- ple BASIC and C programs were forever making those complicated translate-rotate-scale transforma- tions. That's the kind of stuff that PostScript does free, invisibly, and automatically all of the time. Con- trary to all the dire negative com- ments early in the red book, Post- Script should end up nearly ideal for fractal-geometry uses, along with most anything else involving chaos science. An unusual fractal fern To test out the theory, I trans- lated and then upgraded the original code into the PostScript routines found in Figs. 4 and 5. They will give you atypical chaotic beastie known as a Serpenski tri- angle, plus the fern, the second most popular fractal image of all time. Of course, the Mandlebrot Set is numero uno, and I am saving it for sometime later. While you can run the code through any old word processor, you do need a PostScript speaking laser printer or a PostScript emu- lator to get your final copies. You could reverse-engineer them back into BASIC, orelse usethe original listings as they appeared in the Byte article. Even though there's still an awful lot of slop left in the code, I was quite pleased with both the final results and their speed under /problistcreate {mark /counter def probabilities {128 mul round cvi {transforms counter get} repeat /counter counter 1 add def} forall counttomark 128 sub neg dup gt { [1 1 0] repeat} {pop} ifelse] /problist exch def} bind def /doit {problistcreate 1 1 20 {problist rand -24 bitshift get transform 2 copy moveto 0.001 10 rlineto} repeat newpath numdots {problist rand -24 bitshift get transform 2 copy moveto 0.001 rlineto stroke} repeat} bind def % /// demo - remove before use. /// /numdots 6000 def % increase for denser image; decrease to print faster /transforms [ [0.5 0.5 0] [0.5 0.5 1 0] [0.5 0.5 0.5 0.5] I def /probabilities [ .33 .33 .34 ] def 1 setlinecap setli showpage quit newidth 200 300 translate 100 dup scale doit FIG. 4— A SERPENSKI TRIANGLE STRANGE ATTRACTOR done using PostScript. While you can enter this into any word processor on any computer, a printer that accepts PostScript is needed for your final output. 68 PostScript. I elected to create a custom probability table once ahead of time, rather than making slower individual probability se- lections on the fiy. Providing for 128 entries in the table, rather than the expected 100, gives us some further speedup and simplifica- tion. But a lot more cries to be done. When you are experimenting with them on your own, be sure to change the numdots variable to something in the high thousands for your original fast-printing sam- ples that will image in a few sec- onds to a minute or two. Later on, you could increase numdots as high as you need to for top-quality final images that might take hours to print in their larger sizes. One other "gotcha:" The six-el- ement matrices used by the origi- nal fractal people and PostScript differ slightly, to get from one to the other, simply interchange the second and third numbers in the array. Never mind why. There are some amazingly bi- zarre things about the fern image of Fig. 5. First and foremost, larger sizes of the fern original are haun- tingly beautiful. In fact, I've never seen any PostScript code image anywhere that comes even re- motely close. Second, the smaller pieces of the fern are definitely not a small- er, or selfsimilar copy of your whole picture. Unlike ordinary pictures, as you magnify, addi- tional and uniquely different de- tail appears. But that is what fractal stuff is all about. Third, although an apparently random process is used that picks four tasks by using random proba- bilities in random orders, you al- ways end up with the same final image! That will happen re- gardless of which random num- bers get used in which order. That is a stunning example of a strange attractor, otherwise known as the holy grail of fract- aldom. As you might expect, others are seeking out the possi- ble strange attractors thought to underlie the stock-market prices and weather patterns. Despite that, a sick random- number generator will definitely not perform. You have to use a good one. Short repetition se- quences appear to be a no-no. Many more details are in my Apple Assembly Cookbook. Fourth, believe it or not, the entire fern is coded as only 28 numbers in a tiny data array! There's no difference whatsoever between your Serpenski triangle and the fern, except for the 28 numbers. Nor is there any other difference between those and untold billions of other wildly different images. We thus have an absolutely in- credible picture-compaction scheme going on here. For a full- page PostScript fern, the data compaction can approach 300,000:1! Unfortunately, though, your image-regeneration times do get out of hand with compaction levels that are that high. You can forget about real time. In theory, by going to just a few more num- bers, we can create any image at all. Which gets heavy fast. Fifth, and finally, the image really does look just like an au- thentic Black Spieenwort Fern. Now, Black Spieenwort Ferns have Try the Electronics bulletin board system (RE-BBS) 516-293-2283 The mare you use it the more useful il becomes. We support 300 and 1200 baud operation. Parameters: BN1 (8 data hits, no parity, 1 slop bit) or 7E1 (7 data bits, even parity, 1 slap Pit). Add yourself to our user tiles to increase your access. Communicate with other R-E readers. Leave your comments on R-E with the SYSOP. RE-BBS 516-293-2283 VCR's Over 75% of VCR failures are due to mechanical problems. If you fix or maintain VCR's, TENTEL offers fast, universal, easy to use gauges for diagnosing mechanical tape transport problems. Powerful tools fot measuring torque, tape tension, spindle height, tape guide height, head protrusion, drum eccentricity and more! You can't afford to just guess when your customers and your future depends on professional service, done right the first time. FREE CATALOG, Also Video Training Tape Now Available - $24.95 (800)538-6894 n Calif. -(91 6)939-4005 TenteP Corp. 4475 Golden Foothill Pkwy El Dorado Hills, CA 95630 CIRCLE 158 ON FREE INFORMATION CARD CABLE -TV band -stop filters • FOR ELIMINATION OF SEVERE INTERFERENCE • FOR "CENSORING" OF ADULT BROADCASTS ^n SIGMA) FUM1NATOE! • ATTENUATION- 45 dB TYPICAL BANDWIDTH - 4 MHi AT 5 z c > ID -< to o CO CJ z o EC I LU o o < been around for a rather long time, and they sure are pretty, but nobody ever accused them of being very bright. Could the exact same process be used by the real fern to teach itself how to grow? To me, the odds are overwhelm- ing that that does seem to be the case. We thus appear to be tam- pering with some heavy-duty stuff here. What really astounds me over the fern, though, is that you donof really draw it. All you have to do is let it out, and it leaps out of its cage with a vengeance. I guess that is where the "strange" in strange at- tractors comes from in the first place. Oh yes, if you do find the strange attractor that underlies stock-market prices and send it to me, I'll be most happy to send you five of my money machine books. 1 might even consider a free tinaja quest as well. Help wanted How about you helping me for a change? I'm having trouble find- ing some sources of cheap stock plastic metric gears, especially the Module 1.0 size. Any suggestions? Yes, Stock Drive Products carries them, but at five times what I want to pay for them. A free book for your trouble. New tech literature Several manufacturers are newly turning to videotape product in- troductions. Tektronix has bunches of scope and spectrum- analyzer tapes available for you. And Sprague has a free new "vid- eotech paper" on a full bridge motor driver. Speaking of Sprague, they also have a unique new UGN3055U Hall-effect device. The $1.60 parts are addressable, which means that up to thirty of them can share the same two-wire series query line. From the Philips branch of good old Signetics, a fat new data hand- book on RF Power Transistors and a very detailed ap note on all those popular 74HC4046 phase-locked loops. The SGS people have a free soapbox full of EPROM samples, while Texas Instruments has a new free evaluation printed-circuit board for their TL7770-5 supply I /problistcreate {mark /counter def probabilities {128 mul round cvi {transforms counter get) repeat /counter counter 1 add def} forall counttomark 128 sub neg dup gt { [1 1 0] repeat} {pop} ifelse] /problist exch def} bind def /doit {problistcreate 1 1 20 {problist rand -24 bitshift get transform 2 copy moveto 0.001 10 rlineto} repeat newpath numdots {problist rand -24 bitshift get transform 2 copy moveto 0.001 rlineto stroke] repeat} bind def % /// demo - remove before use. /// /numdots 6000 def % increase for denser image; decrease to print faster /transforms [ [0 .16 0] I [.2 .23 -.26 .22 1.6] I [-.15 .26 .28 .24 .44] [.85 -.04 .04 .85 1.6] i def /probabilities [ .01 .07 .07 .85 ] def 1 setlinecap setlinewidth 200 300 translate 30 dup scale doit showpage quit ■■■■■■1 FIG. 5— A FRACTAL FERN DONE IN POSTSCRIPT. Note that only 28 data values are needed to completely define this image. But what's really astounding is that you don't really "draw" this fern— instead, you simply let it out! voltage supervisor chip. Here we go again. Bright blue light-emitting diodes have been newly announced by Sanyo. Is that yet another false alarm? Time will tell. Stock-market quotation de- coders and support software are now available from DATArx. Light- wave is a new, free fiber-optics trade journal. And the Quick Shooter is a low-cost plastic injec- t i o n molding machine from Haygeman Machine. That one uses a drill press for an injection ram. Turning to my own products, I've recently upgraded and im- proved my book-on-demand printed Hardware Hacker II re- prints, covering all of my hacking columns that have appeared in Ra- dio-Electronics. I've also recently released a similar LaserWriter Se- crets test covering my LaserWriter Corner columns over in Computer Shopper. As always, this is your column and you can get technical help and off-the-wall networking per that Need Help? box. The best calling times are weekdays 8-5, Mountain Standard Time. Let's hear from you. R-E "Ymt work with superconductors. Did run know Leonard Bernstein? 70 Audio Update The Audio Answerrnan strikes again ! BECAUSE THIS COLUMN IS WRITTEN FOR the casual hi-fi user, rather than the dedicated audiophile, all the column topics — including the fol- lowing Q's and A's — are chosen to be helpful and/or informative. For this month's column, I've chosen two questions, one practical and the other mostly theoretical. Let me know how you feel about this format. Recording Balance Q. When I'm recording a disc or FM program on my cassette deck, I notice that the right- and left-chan- nel recording-level indicators sel- dom read the same. Sometimes one is higher; sometimes the other. Should I try to balance the channels using the recording-level con trols, or simply let things fall as they may? On some of my dubbed tapes the right-to-left balance seems just fine; on others, the sound seems to come mostly from one side or the other. Is there any way to make sure that things are adjusted correctly? A. First of all, keep in mind that properly adjusted stereo record- ing-level indicators show exactly the same readings only when identical signal voltages are fed to them by the source or by the tape being played. Given the normal signal variations between the right and left channels of a wide-range stereo recording, the readings should coincide frequently, but momentarily. Over the years, I've occasionally encountered recordings and FM programs that, for one reason or another, sounded off-center, and LARRY KLEIN, AUDIO EDITOR I'm sure that a recorder's meters would have confirmed what 1 heard. But on the vast majority of recordings, the signal levels in the two stereo channels will provide a balanced sound stage and average out to about the same reading on both meters. There's an easy way to check the internal balance of your recording circuits. With your record-level controls set similarly, feed a mono signal simultaneously into both channels and check for identical meter indications. If you can't get a mono signal at the tape-output jacks by switching your preamp to mono, and if you can't switch your tuner to mono, you will need to use a single-male/double-female Y connector. When plugged into your amplifier's right or left tape- output jack, it will provide the same mono signal source to both tape-input channels. Assuming that you find a bal- ance problem within your record- er, clean and demagnetize its heads and, most important, try re- calibrating its recording-bias con- trols—assuming that its instruc- tion manual tells you how. (I fixed an unbalanced Nakamichi by doing just that.) If those sugges- tions don't help, call or drop a note to your recorder's manufacturer explaining the problem and the steps you've already taken to han- dle it. He may be able to assist you over the phone, or at least provide the address of the nearest autho- rized repair shop. Although the question is about lack of recording balance, it ■< o 71 Official 1934 SHORT WAVE RADIO MANUAL Build simple, high performance old time shortwave radios! All of the secrets are here: the circuit diagrams, parts layout, coil specifications, con- struction details, operation hints, and much more! This is a compilation of shortwave construction articles from "Short Wave Craft" magazines published in the 20's & 30*S>, lt' s wall-to-wall "how-to." Included are circuit diagrams, photo- graphs, and design secrets of all short- wave receivers being manufactured in 1934 including some of the most fa- mous: SW-3, the SW-5 "Thrill Box", the deForest KR-1, the Hammurland "Comet Pro", and many more. Also included is a new chapter show- ing how you can use transistors to re- place hard-to-find vacuum lubes. You'll even see the circuit that was lashed together on a table top one night using junk box parts, a hair curler and alliga- tor clips. Attached to an an- tenna strung across the base- ment ceiling and a 9 volt bat- tery, signals started popping in like crazy. In a couple of minutes an urgent message from a ship's captain off Se- at Ue over 1500 miles away was heard asking for a naviga- tor to help him through shallow waterl These small regenerative receivers are extremely simple, but do they ever performl This is a must book for the experimenter, the survivalist who is concerned about basic communication, shortwave listeners, ham radio opera- tors who collect old receivers, and just about anyone interested in old-time radio. Great bookl Fun to read! One of the best old-time radio books to turn up in years. Heavily illustrated! Order a copy to day I 8 1/2 x 11 paperback 260 pages only $15.70 postpaid! ["Lindsay Publications 1 [ Box 12-WA6, Bradley IL 60915 ' 1 I Send a copy of Short Wave Radio I Manual. Enclosed is $15.70. Chk, MC. Visa. Send a free cata- log of other books. I Name Address L.— . Zlp_ wouldn't hurt to point out that an audible right-left system unbal- ance can come about through mis- adjustment of speaker-system midrange controls. Because the ear is most sensitive to mid fre- quencies (4 kHz or so), a pair of speakers whose midrange-level controls are adjusted differently will sound unbalanced. Objec- tively, one will be playing louder than the other despite the fact that the same signal level is fed to both. Reflected speaker sound Q. I've read several articles about live-end/dead-end listening rooms, in which the loudspeaker end of the room is heavily damped with acoustical absorption mate- rial and the listener's end is fairly reflective. That is said to improve a speaker's response and imaging properties. Can such a setup be used with speakers that inten- tionally reflect sound from the rear walls, such as electrostatics, planars, or conventional speakers with rear- firing radiators? A. Ideally, a loudspeaker's sound-radiation pattern — which, indirectly, is what we are talking about here — should be designed with a particular recording-micro- phone setup in mind. Since that is impractical given the variety of re- cording practices, the best that the speaker designer can do is to de- sign a system that will present a reasonable stereo image with most program material and in most of the rooms in which it is likely to find itself. In a con- ventional listening room, the speaker sound that reaches a lis- tener's ears consists of the direct sound from the drivers plus a large amount of early- and late-arriving reflections bounced from the walls, floor, and furniture. If a speaker's immediate environment has sufficient acoustical absorp- tion, most of those early reflec- tions will be soaked up or severely attenuated. The late-arriving re- flections from the more distant walls will be relatively unaffected. The advocates of such an arrange- ment state that its advantages in- clude the preservation of accurate directional cues and instrumental detail. Speakers designed to radiate multidirectionally or with strong rear radiation obviously shouldn't be installed in a non-reflective lo- cation, since they intentionally use the adjacent walls to deliver large percentages of reflected (and, therefore, delayed) sound to the listener's ears. As noted by German acoustic researcher Helmut Haas in 1951, as long as the interval between the delayed and direct sounds doesn't exceed 40 to 50 milliseconds, the ear fuses the two into a single event. The de- layed sound is heard as an echo only when the 50-milfisecond de- lay is exceeded. An unexpected psychoacoustic effect of delays of between 5 and 30 ms is to "expand" the perceived sound source. Not only does the sound increase in volume, but it also takes on — in Haas' words — a "pseudostereophonic quality." (That pseudo-stereo effect proba- bly accounts for the widened sound stage provided by a popular speaker design that employs eight small rear drivers and one for- ward-facing one.) Incidentally, a speaker system's sound reflected from a nearby rear wall has little in common with the reflections in a concert hall from walls perhaps 50-100 feet away — Respite the efforts of some manufacturers to imply that their deliberatively re- flective speakers mimic the acous- tics of concert halls. For good reasons, open-back di- polar and omnidirectional systems (which have included some of the best speakers on the market) and rear- radiating speaker systems are necessarily more placement-crit- ical than conventional forward-ra- diating types. The problem is to arrive at a spacing from adjacent surfaces that enables the reflected energies to make a positive — rather than destructive — contribu- tion to the sound and stereo image perceived by the listener. Which type of speaker design is the best? My feeling is that as long as recording techniques (and room acoustics) are not standard- ized, most otherwise well-de- signed systems will sound good on most recordings. In truth, speakers that radiate substantia! energy rearward have special in- stallation constraints, but their ad- vocates will tell you that they are more than worth it. R-E 72 Shortwave Radio The future of shortwave broadcasting STANLEY LEINWOLL MORE THAN 130 COUNTRIES CUR- rently operate international short- wave broadcasting services. Many of them use shortwave broadcast- ing as an instrument of their for- eign policies. The United States, the Soviet Union, and Great Brit- ain alone carry approximately 6,000 frequency hours daily to every continent on Earth in every major language, and also many minor languages. In addition, a large number of countries, including Brazil, Argen- tina, the People's Republic of China, Mexico, the USSR, and many developing countries use shortwave for domestic broad- casts. Those national services are aimed primarily toward large rural and suburban audiences. Because of the popularity and versatility of the shortwave spec- trum, the number of frequency- hours scheduled for High-fre- quency (HF) broadcasting has quadrupled since the end of World War II, from about 8,500 fre- quency hours to more than 35,000 today. And as technology has ad- vanced, the standard transmitter power has increased from 50-100 kW in the late 1940's to 250-500 kW in the1980's. Rapidly growing demand for a limited number of frequencies, coupled with a power race, has re- sulted in increasing chaos in the HF broadcast bands. The 9-MHz band (9500-9770 kHz) has been monitored at four different loca- tions in Europe. The results are summarized in Fig. 1, which shows occupancy during the period from February 13-17, 1989. 22tO 2400 The solid horizontal lines show gins, in 5-kHz increments. It can actual users, and the frequency is be seen that, during prime broad- shown vertically along the mar- casting hours, virtually all frequen- > Z C > 33 -< 3) 77 Put Professional Knowledge and a COLLEGE DEGREE in your Technical Career through HOME STUDY o o o UJ o a < DC 78 Add prestige and earning power to your technical career by earning your Associate or Bachelor degree through directed home study. Grantham College of Engineering awards accredited degrees in electronics and computers. An important part of being pre- pared to move up is holding the right college degree, and the abso- lutely necessary part is knowing your field. Grantham can help you both ways— to learn more and to earn your degree in the process. Grantham offers two degree pro- grams — one with major emphasis in electronics, the other with major emphasis in computers. Associate and bachelor degrees are awarded in each program, and both pro- grams are available completely by correspondence. No commuting to class. Study at your own pace, while continuing on your present job. Learn from easy-to-understand lessons, with help from your Grantham instruc- tors when you need it. Write for our free catalog (see address below), or phone us at toll-free 1-800-955-2527 (for catalog requests only) and ask for our "degree catalog." # Accredited by the Accrediting Commission of the National Home Study Council GRANTHAM College of Engineering 10570 Humbolt Street Los Alamitos, CA 90720 'FROM INFORMATION PUBLISHED BY THE IFRB ■ 'FROM INFORMATION BASED ON WORLD-WIDE MONITDRING(BSC) FIG. 2 TABLE i Kilohertz J979 Pre-1979 Kilohertz Implementation WARC Bandwidth Spectrum 5950 - 6200 Bandwidth Date 5950 - 6200 250 250 7100 - 7300 200 7100 - 7300 200 — 9500 - 9775 275 9500 - 9900 400 July 1, 1994 11700- 11975 275 11650 - 12050 400 July 1, 1989 none — 13600- 13800 200 July 1, 1989 15100 - 15450 350 15100- 15600 500 July 1,1989 17700 - 17900 200 17550 - 17900 350 July 1, 1989 21450 -21750 300 21450- 21850 400 July 1, 1989 25600-26100 500 25670- 26100 430 January 1, 1982 Total Spectrum 2350kHz 3130kHz cies are occupied by at least one broadcaster. In many cases, two or more broadcasters use the same frequency simultaneously. For more than forty years broad- casters have been grappling with the problem of increasing con- gestion in a severely restricted spectrum. One method of alleviat- ing serious overcrowding is to ex- pand the supply of the broadcast frequencies. That can be accom- plished by an appropriate radio conference with the authority to re-allocate spectrum for the broadcasting service. The last such conference was held in 1979; the World Administrative Radio Con- ference (WARC-79) was convened in Geneva for approximately ten weeks. WARC-79 The less-developed countries at WARC-79 opposed the Soss of a fixed shortwave spectrum but, at the same time, wanted a high-fre- quency broadcast planning con- ference. Their position was that the developed countries had con- trol of the high-frequency broad- con tinued on page 100 Drawing Board The world of video BEFORE WE GET INTO CIRCUITS AND stuff, there's a piece of follow-up business I have to take care of. If you're a regular reader, you'll re- member that we ran a contest some months ago to see who could come up with a good way to use the space left empty in the EPROM character generator we designed. There were lots of entries and lots of ideas, but the best one came from Randall Logan of British Columbia, Canada. He used the remaining space in the EPROM to build an automatic hex to decimal converter that still left enough room in the EPROM for the character codes we worked out as our circuit was being developed. The circuit details are on page 72 of the September 1989 issue of Radio- Electronics. Since it's the height of tedium to generate the code for the EPROM, Randall wrote a BASIC program to create the data. He sent me a copy of it and, as promised, I'm sharing it with all of you- — it's shown in List- ing 1. Although the program is written for an IBM or compatible, it won't take a lot of work to con- vert it to the BASIC dialect used by other computers. The program is well-commented so you shouldn't have any trouble figuring out how it works and what you'd have to do to change it. Just about the only reason for changing it would be to match the data outputs of the EPROM to your seven-segment display. The seg- ment assignments (a, b, c, etc.) are pretty much standardized, but sometimes it's easier to lay out a PC board by switching the order of the EPROM data pins. In any event, you've got the circuit and now you've got a program to gen- erate the data for the EPROM. As a last note on the subject, the program will create a file 2049 bytes long. The extra byte comes about because BASIC (at least IBM BASIC) adds an "end of file mark" (1Ah), whenever it writes a data file. It isn't a big deal since the first 2048 bytes are the ones going into the EPROM, but being aware of the extra byte (as well as knowing why it's there) means there's just one less thing to worry about. And now for something com- ROBERT GROSSBLATT pletely different. In going through the mail I've received recently, it's evident that video is a really popular subject. Lots of readers are fascinated by the hardware but haven't gotten their hands dirty because they're not familiar with video signals, ter- minology, and hardware require- ments. Over the next few months we'll go through some video basics together. We'll take apart the NTSC standard and examine the individual parts of the wave- form. Once we know what we're looking at, we'll see what has to be done to design video circuitry. It's LISTING 1 ioo 105 110 120 130 140 150 160 170 ISO 190 200 210 220 230 240 250 260 270 280 310 320 330 340 350 360 370 380 390 400 410 415 420 430 440 450 460 470 480 THIS PROGRAM WILL GENERATE A 204B BYTE BINARY FILE (EPROM.DAT) CONTAINING THE DATA REQUIRED FOR THE EPROM IN THE BINARY TO HEX/DECIMAL CONVERSION CIRCUIT AS SHOWN IN THE SEPTEMBER ISSUE OF RADIO ELECTRONICS, PAGE 72 WRITTEN BY RANDALL LOGAN, 1989 DESCRIPTION OF VARIABLES B-NUMBER BASE (10 OR 16) N^NUMBER TO CONVERT (0-255) P=SELECTED DIGIT POSITION WITHIN NUMBER (0-3) Q=DIGIT VALUE (0-9) FOR DECIMAL #'S AND (0-15) FOR HEX #'S V=TEMPORARY WORKING VARIABLE S( )=CHARACTER SEGMENT DATA (16 ELEMENT ARRAY) Z=USED TO DETERMINE IF LEADING ZERO BLANKING IS REQUIRED REM REM REM REM REM REM REM REM REM REM REM REM REM REM REM REM CLS DIM S( 16) REM READ SEGMENT DATA FOR ALL 16 CHARACTERS (0-F) INTO ARRAY FOR I = TO 15:READ S(I):next DATA 63,6,91.79,102,109,125.7, 127,111,119,124,57,94, 121,113 REM REM NOW GENERATE BINARY FILE FOR EPROM PROGRAMMER (EPROM.DAT) REM OPEN "EPROM.DAT" FOR OUTPUT AS #1 FOR B - 10 TO 16 STEP 6 FOR N = TO 255 V = N FOR P = 3 TO STEP -1 D - INT(V / (B " P)): Z = Z + D V=V-D*(B~P) REM LINE 420 BLANKS LEADING ZEROS (FOR DECIMAL VALUES ONLY) IF Z = AND P > AND B = 10 THEN PRINT SI, CHRS(0); : GOTO 440 PRINT 81, CHR$(S(D))r NEXT P Z ■ 0: REM RESET ZERO BLANKING TEST VALUE NEXT N NEXT B CLOSE #1 > Z > 3 79 03 o z o CC h- O LJJ _i UJ g < EC complicated enough to be inter- esting and just hairy enough to be fun. Who could ask for more? Some video basics Back in 1953, a group of relatively unknown people sat down to- gether and made some decisions that affected the lives of every per- son in this country (and some other countries as well). That sounds like the beginning of a trashy spy novel, but it's not — it's the beginning of the television standard. The people who made the decision were known as the National Television System Committee, and they established the color-TV standard known as NT5C. There are lots of jokes about what the initials stand for (Never The Same Color, etc.), but whatever you might think of it, NTSC video is (in the United States) the name of the game. All the video circuitry in a televi- sion set is designed with one job in mind — to control the movement of the electron beam that scans across the inside of the picture tube. The video signal that moves the dot on the screen and deter- mines how bright it will be is one of the most complex signals in common use. The key to knowing how video works and making sense out of video hardware is un- derstanding all the component parts of the video waveform. All video, either broadcast NTSC or high-resolution comput- er, is made up of the same basic elements. As a simplified explana- tion, the electron beam in the pic- ture tube scans across the screen from left to right and back again. When it reaches the bottom right of the screen, it moves to the up- per left and starts anothertrip back and forth across the screen. The rate at which it travels left to right, and how often it moves back to the top right of the screen are all de- fined in the NTSC standard. The video signal fed to a TV set has two basic jobs. The first is to control the beam's movement, and the second is to control the brightness of the beam. The for- mer tells the TV where to put the picture and the latter tells the TV what picture to put there. Even though the video circuitry ■ 3V - O/VE. LJM£. OFA/TSC -JrAMDAKD COC0K W0E O - O -¥£>!/?£ - © //. / Jf/CAQS£CQf/D5 WOEO MFOKMAT/OAt- 52. ¥■ M/C#03£COAtD5 FIG. 1 in a television set is constantly moving the beam around the screen from left to right and top to bottom, there's no way to guaran- tee that the movement is going to be at the precise rates required by the NTSC standard. As we all know, nothing is forever; compo- nents age, values drift, and it wouldn't be long before a TV — no matter how well made — would go out of alignment. Most television sets move the dot around the screen at rates that are close to the NTSC standard, but they have built-in slop factors. That means that there's enough lat- itude in the TV's control circuitry to enable it to be adjusted to strict NTSC timing. Older television sets had horizontal and vertical hold controls, but most of the newer sets do it automatically. The horizontal and vertical con- trol of the television image is the job of two components of the NTSC signal known, appropriately enough, as horizontal sync and vertical sync. The former tells the electron beam to move back (or flyback) to the right edge of the screen and the latter causes the beam to move back to the upper right hand corner. Before we look at the big picture (sorry about that), let's take a look at the most basic unit of the video signal — a horizontal line. The NTSC standard calls for 525 lines of video for each frame (the entire picture), and there are two fields per frame. The horizontal line The whole video signal is really a series of repeated horizontal lines of control and picture informa- tion. The NTSC standard allows a total time of about 63.5 microse- conds for each line, so a bit of arithmetic tells us that the fre- quency is about 15.75 kHz. I'm using approximate numbers be- cause the exact value is different for color and black and white. That rate is referred to as the "horizon- tal scan frequency," and during each cycle the video signal is con- trolling the placement of the im- age and carrying the image information, as well. The illustration in Fig. 1 shows you exactly what's happening in each horizontal line. The left-hand side of the picture corresponds to the trailing edge of the horizontal sync pulse, which is labeled as "2" in the drawing. As you can see, about 20% of the line time is de- voted to control signals, and each part of that section has it's own name and allowable duration. Most television sets "overscan" the image. That means that a bit of the left and right edges of each line take place outside the screen area — think of it as slightly zoom- ing in on the line. That's done for a variety of reasons; most impor- tant, it makes sure that the only part of the image you'll see on the tube is picture information — the control data is always off screen. If you're looking at a color im- age, the first important piece of information sent on each line is the colorburst signal. That is about 8 to 10 cycles of a 3.579545-MHz clock, and it's used as a standard to continued on page 91 80 Compu-erDigesi BUILD THE PORT-A-MATIC '/■ Keep tabs on your expansion bus ROBERT GROSSBLATT There are lots of reasons for the PC's popularity, and if you pop open the case you'll find eight of them on the motherboard. IBM's decision to provide rela- tively complete details on the ar- chitecture of the machine was an invitation for designers to create add-on hardware for the PC. As things stand now. there are after- market products for the PC fam- ily that can do just about anything you can imagine — and a lot you can't. No matter what kind of pe- ripheral you plug into the bus, chances are that the micro- processor (8088, 80286, 80386, even the 80486} will talk to it through an I/O port. Peripherals include video adapters, serial and parallel ports, the keyboard, floppy- and hard-disk control- lers, and more. Since Intel micro- processors can address many ports (even the lowly 8088 can address 65,536 different ones), you'd think that port-address conflicts would never occur. Think again. IBM has reserved specific ports for specific purposes, and as PC's have evolved, additional ports were reserved. The devices using those ports make the computer more powerful, but they also make it easier to configure some- thing incorrectly. The Port-A-Matic makes it easy to keep track of I/O operations be- cause it provides a real-time in- dication of which ports are being accessed. The Port-A-Matic pro- vides a three-digit hex display of the port address, and it lights a discrete LED to provide a l-of-16 indication of which device is con- nected to the port. Another dis- crete LED tells you whether the CPU is doing a read or a write to the port. You can easily customize the circuit so that the discrete LED's light up for a desir- ed I/O port. Even though the Port-A-Matic is a fairly complex circuit, you should be able to build it for well under $75. PC- board patterns will be published in PC Service. The PC bus Since the Port-A-Matic lives in one of the PC's expansion slots continued on page 84 EDITOR'S Work Bench/ Floppy Heaven I just found the ultimate floppy- disk controller: the newly re- leased CompatiCard IV (CC4)from MicroSolutions (see Fig. 1}. I've been searching for something like it for a couple of years; MicroSolutions has really come through. FIG. 1 What I've long been looking for is a controller that allows three internal drives and that also has a DB-37 connector for an exter- nal drive — in my case, an Irwin 785 tape-backup unit. Why do I want three internal drives? I get review software in all four of the standard formats (360K. 720K. 1.2MB, and 1.44MB), so I need high-density versions of both 3.5-inch and 5.25-inch drives. However, for trading files with friends and business associates, I need a 360K drive, because 1.2MB driv- es can't reliably write to 360K dis- kettes. (Actually, they can write reliably enough; the problem is track mis-alignment when one > z c > CD 5 81 drive tries to read a disk format- Led on another drive. I've had no problem trading either of the 3.5- inch disks. Other controllers typically al- low two internal drives only, or two internal and two external drives. However, the latter supply only the external DB-37 con- nector, so it's impossible to con- nect a third internal drive with a standard 34-pin edge connector. MicroSolutions sensibly solved that problem simply by wiring an additional 34-pin dual-row head- er connector in parallel with the DB-37. So connecting a third (and fourth) drive internally is now as simple as connecting the first two drives; Just attach a power connector and a normal 34-con- ductor data cable and you're ready to roll. If that's all there were to the CompatiCard IV, I'd be im- pressed, but there's more; several items will be particularly inter- esting for owners of older PC and XT compatibles without built-in support for high-density 5.25- inch drives or 3.5-inch drives of either density. Advanced features The most innovative feature is support for a new 2. 8MB diskette format. No, the format is not IBM endorsed — but as of this writing (early October), there are rumors that IBM will soon introduce a 2.8MB format using the same vertical recording format as Mi- croSolutions'. To handle the increased amount of data stored on a 2.8MB disk in a reasonable amount of time, the data transfer rate has been quadrupled (com- pared with that of a standard 360K drive) to 1 Mbit/second. The drives, however, are expensive (about S450), as are the diskettes (about S10). No one knows if yet another diskette format can catch on. o However, the CC4 is still a good g buy because not only does it look cr. forward to the future, it goes a o long way toward maintaining j-j-j compatibility with past formats. o g Upgrading PC's and XT's £ You can't use high-density 82 drives on most PC's and XT's be- cause their floppy-disk control- lers work only at a single data transfer rate (250 kHz), and high-density drives need 300- and 500-kHz rates. Even with the right controller, there may be software problems; the BlOSes of older machines don't know how to handle the ad- ditional tracks and sectors of high-density drives. You may be able to get around the BIOS prob- lem by installing a 360K drive as drive A, and loading a software driver via CONFIG.SYS to access a high-density drive as drive B or higher. But you wouldn't be able to install the high-density drive as drive A, unless you gave up the ability to boot from A. The reason is a classic Catch-22; you can't load the driver until you've load- ed the driver to know how to load the driver. Anyway, the CC4 solves that problem by including an on- board EPROM that occupies 2K of the address space above the video adapters; that EPROM can be viewed as a BIOS upgrade for older PC/XT models that allows them to access the newer high- density floppy-disk drives. The only limitation is that the EPROM software applies only to the first two drives; if you add a third (or fourth) drive, you'll have to load a device driver, which oc- cupies about 4.5K of memory. The ROM allows another neat trick, the ability to boot from any floppy drive attached to the card. For example, I have a 1.2MB drive-A, a 1.44MB drive-B, and a 360K drive-E (drives C and D are hard disks). If at any time I want to boot from the 360K drive, all I have to do is put a formatted 360K system disk into the drive and the CC4 handles the rest. At that point the 360K drive be- comes drive A, and the original drive B remains as it was. To ac- cess the 1.2MB drive, I'd have to load a copy of DRIVER. SYS (which comes with DOS 3.3) when booting. The CC4 can also function as a secondary controller. In that con- figuration, you'd leave your exist- ing floppy controller alone, and move a jumper on the CC4 so that data would flow via a different set of I/O ports. A software driver would then handle the dirty work of transferring data in the usual fashion. Incidentally, if you've got an AT compatible with a standard West- ern Digital combined hard/floppy controller (model number 61-000107-00. as shown in the upper left corner of the board), you can disable the on-board controller simply by moving the shorting block from pins E2 and E3 to pins E2 and El. What you're really doing is assigning the WD board to a different set of I/O port addresses. I do that be- cause the Irwin controller must work off the normal address range. MicroSolutions has bent over backward attempting to make the CC4 flexible and easy to con- figure. For one, the configuration DIP switches are located at the top of the card, so you don't have to remove if from your PC to change settings. Also, you can choose from six interrupt levels, three DMA channels, four I/O port ranges, two drive-speed set- tings, and seven EPROM address ranges. A special set of jumpers allows you to supply power to ex- ternal drives, if necessary. You can even connect an 8-inch drive to theCC4! The CC4 also comes with sev- eral useful utility programs. One allows you to format diskettes in the background (i.e., while run- ning your word processor or an- other application); another al- lows you to format high-density disks if you're running an early version of DOS. In short, there's no doubt that the CompatiCard IV is the most versatile floppy-disk controller on the market. Highly recom- mended, — Jeff HoItzman|CI>4 Slick! A Drawing-Management System for AutoCAD If you're a regular AutoCAD user you know that it doesn't take much time at all for your hard disk to fill up with drawing files. They can be completed jobs, works in progress, or libraries of blocks to insert in new drawings. The one thing they have in com- mon is a that they all have to be available all the time— it's a well known fact that the more draw- ings you produce, the more draw- ings you have to have on hand. Managing your store of draw- ing files gets to be a full-time job since the DOS limitation of eight- letter file names can put a real strain on anyone's imagination. And while the difference between TRANS835.DWG and TRANT835.DWG maybe remem- bered for about two minutes after you've created the files, things get somewhat obscure six months down the line. Although there are several third-party AutoCAD utilities around to help you manage draw- ings, none of them are as ver- satile or convenient as Slick!. Not only does it give you a painless way of dealing with drawings, but after you've used it for a while, you'll wonder how you ever managed without it. Slick! is available in four ver- sions ranging in price from $95 for the most basic version to $250 for the top of the line. But even the least-expensive package can save you lots of time and brain damage as soon as you be- gin using it. When you run Slick!, you're presented with a graphic repre- sentation of your disk — directo- ries on the left and files on the right. As you scroll through the directories, Slick! will list the DWG and SLD files on the disk. When you find the ones you're looking for, you can view as many as four files on the screen at once by moving the cursor to the file list and tagging the files you're interested in. The tagged files can be displayed in a variety of selec- table windows similar to the viewports found in AutoCAD Re- lease 10. Once you get the files on the screen, all the Slick! com- mands are accessed through sev- eral pull-down windows at the top of the screen. You can zoom and pan in any of the drawings and, if you're look- ing at a 3D drawing, you can also change the viewpoint just as you would with AutoCAD's VPOiNT command. You can also get a list ESC I FILES I OPTIONS 1 UTILITY I File i COLUMBIA. DWG FIG. 2 of the layers and blocks in the drawing and have any of them displayed on the screen as well. Slick! also gives you the ability to copy, rename, or delete files as you're viewing them. That comes in really handy when you're doing disk housekeeping since it's nice to look at a drawing before you delete it. One of Slick's neatest features is being able to scroll through drawing files on the graphics screen. Choosing the files option will give you a list of the drawings in the current directory and choosing one of them will cause it to be immediately drawn on the screen in the current window. Slick! puts drawings on the screen from three to ten times faster than AutoCAD so it doesn't take long to scroll through a di- ITEMS DISCUSSED • CompatiCard IV ($149), Mi- croSolutions, 123 W. Lincoln Highway, DeKalb, IL 60115. (815) 756-3411. CIRCLE 48 ON FREE INFORMATION CARD • Slick! (Level 1. $95: Level 2, $150: Level 3. $195; Level 4, $250), CAD Systems Unlimited. 5201 Great America Parkway #443, Santa Clara, California 95054. CIRCLE 47 ON FREE INFORMATION CARD rectory's worth of files. And since you can select viewports while you're looking at a drawing, you can display the full drawing in one window with three different zoomed views of it in the other windows at the same time (see Fig- 2). Don't overlook the fact that Slick! will display both AutoCAD and AutoSketch slides, as well as drawings, and you can zoom and pan around slide files with the same resolution you get with drawing files. No matter how much you zoom in on a slide file, a straight line stays straight and text stays readable — no jaggies. That's really useful for 3D draw- ings since we all know about the limitations of AutoCAD's HIDE command. You'll wait forever for AutoCAD to remove hidden lines, only to have the resulting image disappear as soon as you issue the next command. If you make a slide of the draw- ing after AutoCAD has removed hidden lines, you can use Slick! to view the SLD file. That will let you pan and zoom to any part of the image you want to examine with no loss in resolution. Try doing that in AutoCAD! Of course, being able to get an image like that on the screen isn't as useful as getting it on paper. That brings us to the more ad- continued on page 90 > z c > 3} -< fig. 3. COMPLETE SCHEMATIC DIAGRAM of the Port-A-Maiic. lines, which appear on expan- sion-bus pins A22— A31. Power and ground are supplied to the board through pins B29 and B31, respectively. The card also monitors three control signals. Pins B13 (Tow) and B14 (Tor) are active-low lines that indicate when the micro- processor is either writing or reading an I/O port, respectively. (Recall that the microprocessor has separate signals to indicate reading and writing to and from main memory and I/O ports.) Last, the Port-A-Matic needs aen (pin All), an active-high line that lets expansion-card circuit- ry know that the computer is per- forming a DMA (Direct Memory Access) operation, the speedy transfer of data from one place to another without microprocessor intervention, PC and XT compatibles (and some older AT compatibles) nor- mally use the Intel 8237 as a DMA controller. However, most of the new AT compatibles (both 80286 and 80386 varieties), use VLSI chip sets instead of discreet com- ponents; the functions originally performed by the 8237 are car- ried out inside the VLSI's. During a DMA operation, all other controlling devices must relinquish their use of the bus, otherwise bus contention and garbled data will result. The mi- croprocessor is put to sleep by a signal that gets routed on the motherboard, and any controller on the expansion bus gets noti- fied by a high on aen. The Port-A-Matic is only a monitoring circuit — it doesn't have to take control of the bus to do its job. Even so, the Port-A- Matic still has to pay attention to aen because some DMA opera- tions involve I/O addressing, and they happen so frequently that the Port-A-Matics display would flicker without meaning if it de- coded them. Whenever aen becomes active, the Port-A-Matic ignores whatever appears on the bus. If that sounds like a draw- back, it's not. The board would work perfectly if it didn't ignore aen, but the display would be meaningless. So the board was designed to be selective about the ports it responds to. PC PORT ADDRESSING Even though IBM-compatible PC's use I/O ports for many types of operations, there's a surprising lack of standards. Most of the ports reserved by the computer for basic operations (keyboard, video, disk, etc.), use addresses that remain constant from machine to machine, but when it comes to printer and communications ports, things begin to get considerably less consistent. The first serial and parallel ports (COM1 and LPT1) are usu- ally located at 03F8h and 03BCh. respectively, and COM2 appears at 02F8h. However, other ports are less clearly de- fined. LPT2 can be at 0278h. 0378h. or other addresses. Ports COM3. COM4, and LPT3 are even less clearly defined. In order for Port-A-Matu to decode those ports, you must find out exactly which ad- dresses are used by your hard- ware. You can usually obtain those addresses from the docu- mentation thai came with your peripheral cards; alternatively, various software tools can help. The best program of that nature is DIAGS.EXE. It was written by Joan Riff and is in the public domain, so you should be able to find it by log- ging onto your favorite bulletin board. It's a complex program, but the accompanying docu- mentation (DIAGS.DOC) is well written and covers every aspect of using the program. How il works Now that we know what signals the Port-A-Matic uses, let's see how it works. The block diagram in Fig. 2 gives an overview of cir- cuit operation. The ten address lines from the I/O slot are always present at the Port-A-Matics in- put buffers, but the only data that the board pays any attention to is whatever happens to be there during an I/O operation. When the control circuit senses that a port is being accessed, it latches the address in the buff- ers, then checks the address against the table that is stored in the port selector. If there's a match, the control circuit is notified, but that's not the end of the story. The Port-A- Matic still has to check the state of aen to make sure that it's not looking at a DMA operation. If the circuit sees that there's no DMA operation going on (aen is low), it asserts a master enable signal that causes the rest of the Port-A-Matic to process the data. The address in the input latch is transferred to the display buff- er and multiplexed out to the three-digit hex display. At the same time, the master enable sig- nal will cause one of the two ac- tivity LED's (read or write) to light up. The data coming from the port selector will also be decoded and the LED associated with that port will also light up. All of that activity is controlled by timers, so the Port-A-Matic will display each valid port address for about a half a second. A complete schematic of the Port-A-Matic is shown in Fig. 3. The inptit buffers consist of IC3-IC5. Those 74LS367's con- tain two groups of buffers in a single package, one four bits wide and one two bits wide, and each section has its own output- enable pin. The four-bit sections in IC4 and IC5 handle the lower eight address lines. The two-bit section in IC4 is used as the buff- er for the Ior and Tow signals com- ing from the PC bus. That leaves the two-bit section of IC5; al- though it's devoted to the two up- per address lines, A8 and A9. you can see in the schematic that they are handled differently. The reason for that will become clear after we examine the rest of the circuit; but in a nutshell, doing things the way we did simplified the design and reduced the parts count. High address lines Both A8 and A9 are connected to IC3, a 74LS74 set up as a two- bit data latch. When the Port-A- Matic detects a valid address, the master enable signal clocks whatever happens to be on A8 and A9 into IC3, and that data is presented to the input pins of the two-bit section of IC5. Setting up 86 the address buffers that way rep- resents a design compromise, be- cause the 74LS74 is just a pair of D flip-flops, not a true latch. The price you pay for using it in that manner is that, contrary to what everybody tells you, the data at the input doesn't show up at the output when the chip is clocked. Instead, that data actually ap- pears one clock pulse later. That could have serious con- sequences for the Port-A-Matic since it means that there's a pos- sibility of missing a one-time- only port access by the computer. Fortunately, as we'll see, there's a relatively easy fix for that. For now, it's important just to be aware of the problem. The control circuit is made up of a handful of gates and passive components, along with IC11, the EPROM containing the port selection look-up table. The con- trol circuit's job is to issue the master enable signal — a low-go- ing pulse at the output of IC2-b. When an I/O operation takes place, it causes the output of IC2- a, a nand gate, to go high. That signal is in turn fed to one leg of IC2-b, another nand gate whose job it is to issue the master en- able signal. It's also inverted by ICl-d, a nor gate set up as a sim- ple inverter, and the resulting low enables the outputs of the four- bit sections of IC4 and IC5, which thereby causes the lower DATA AND STATUS PORTS Most I/O operations actually involve the use of several se- quential port addresses for data, status, control, etc. We programmed the prototype to respond only to data ports. The reason is that if you pro- grammed the same LED number into all addresses asso- ciated with COMI ( for example] , the least significant digit of the display would flicker so rapidly that it would be all but impossi- ble to read. So unless you have a particular reason to monitor control and status ports, you'll find it's more useful for Port-A- Matic to respond only to the data port. eight bits of the address bus to show up at the corresponding ad- dress inputs of IC11. the port-se- lector EPROM. The same signal from iCI-d also enables the out- puts of the EPROM. We'll get into the details of the look-up table later; for now it's only important to know that bit 7 of each table entry is used as the enabling toggle for port ad- dresses. In particular, that bit will be cleared for a valid address and set for an invalid address. The D7 line of the EPROM is fed back to ICl-a, one input of a nor gate; the other leg of the gate is connected directly to aen from the bus. If either input to ICl-a is high, either the EPROM says to ignore that address, or the com- puter is doing a DMA operation. (Actually both may be true.) In any case, the output of ICl-a will be low and, since it's connected to the other leg of IC2-b, no master enable signal will be issued. If, however, a high is issued from ICl-a, that high is fed to IC2-b. and since the other leg will also be high (because IC2-a de- tected an I/O operation), the out- put of IC2-b will go low. That is the master enable sig- nal that the Port-A-Matic has been waiting for; when it's re- ceived the rest of the circuit will be activated. Before we continue, however, let's take another look at what's happening with A8 and A9, the two high-order address lines from the bus. If it's the first time a particular I/O address has shown up on the bus, the states of AS and A9 won't be clocked through IC3 and then show up at the inputs of IC5. That is because the 74LS74 is clocked by the master enable sig- nal, and that won't be generated until a valid I/O address shows up at the address pins of IC11, the port selector EPROM. In other words, we need the master en- able signal in order to produce the master enable signal. The situation, however, isn't as ridiculous as it seems. A circuit design, like most other things in life, is the product of inspiration, realization, and compromise. You begin with a list of design criteria and, once there's some working silicon on the bench, you have to weigh real-world practicalities against breadboard idealism. It would certainly be possible to redesign Port-A-Matic to elimi- nate the problem, but the price would be an increase in circuit complexity, parts count, and cost. And those considerations are just as important as circuit operation. Further, increasing the parts count increases the possibility of unforeseen circuit glitches, and raises the power re- quirements. And the more com- plex the circuit, the more complex the PC board. For all those reasons, we decid- ed to come up with a better solu- tion. The solution involves mak- ing a relatively minor operational compromise in the circuit, and it involves using a bit of creative construction in building the look-up table. However, before we can get into building the look-up table, we have to know how the rest of the circuit operates. So, for now, let's just assume that an I/O address has been put on the bus, the Port-A-Matic has check- ed the port-selector EPROM, and the master enable signal has been generated. The master enable signal Once a valid address is de- tected, the main job of the master enable signal is to load the ad- dress data into the display buffer, activate the display timers, and turn on the display. The master enable signal from IC2-b is inverted by IC2-C, and the resulting high triggers the latch-enable input of IC6, a 74LS373 octal latch. The data stored there is then presented to IC7. a 74LS257 quad two-input multiplexer — the electronic equivalent of a four-pole, two-po- sition rotary switch. By putting a high or low on the select control (pin 1). one of the two sets of in- put lines will be routed to the out- put pins. You can tie the 257 directly to a bus because a low on the output- en able (pin 15) fc "floats" the outputs (effectively z removes them from the bus). > That feature is important be- < cause the display section can io handle only eight inputs, but the => 87 to o z o i _l LU Q Q < 88 circuit must deal with ten lines {A0- A9). Since we're only using three seven-segment digits for the dis- play, one question is: Why should we bother with display multiplex- ing at all? Multiplexing is a good way to reduce parts count, but the break-even point is about three digits. The reason is that we need a hex, rather than a decimal, dis- play. That means using a character generator that can de- code all the numerals from to 9. as well as the hex digits A to F. Unfortunately, such character generators are hard to find. Motorola makes one, and HP has some smart, self-latching hex displays, but both solutions are expensive, and the parts are hard to come by in small quantities. So we built our own; here's how. The Port-A-Matic divides the ten address lines into three groups: A0-A3, A4-A7, and A8— A9. The multiplexing control circuitry is composed of IC8-b (half of a 556 dual timer). IC12 (a 74LS138 decoder). IC13 (a 4040 counter), and several gates. The basic multiplexing clock is provided by IC8-b. It drives the 4040 and the resulting binary count drives the 74LS138's select pins. That puts a series of se- quential lows on the bases of the display pass transistors (Q4— Q6). and each of the digits will thus light up in turn. Gates IC2-d and ICl-b decode the bin- ary count from the 4040 and pro- vide a reset pulse for the counter whenever the count reaches three. Multiplexing the display isn't much use unless the data being fed to the display is multiplexed as well. The data and the display must be synchronized so that the right data is presented to the dis- play inputs when the right dis- play is illuminated. The two outputs of the 4040 that drive the 74LS138 also control the order in which the address data is fed to the display circuit. As long as the Ql output of the 4040 is low, the outputs of IC7 (the data multiplexer) will be enabled. In addition, the same line that enables IC7's outputs is inverted by ICl-c, so the outputs of the CHOOSING EPROM'S FOR THE PORT-A-MATIC Much of Port-A-Matic s opera- tion depends on the proper functioning of IC 1 1 , the port-se- lector EPROM. Every I/O opera- tion performed by the computer is checked by IC11 to see whether the Port-A-Matic should respond to the port ad- dress on the bus. Not only does IC1 1 play a ma- jor role in the circuit, it has only a limited amount of time to do its job, and the duration of that time may be critical. The reason is that even though the 8088 takes between eight and ten clock cycles to perform an I/O operation (unless the hardware or software slows things down by adding wait states), the ad- dress remains valid on the com- puter's bus for even less time than that. Even though computer tim- ing is measured in microse- conds and EPROM timing is measured in nanoseconds, using a standard 2716 (with a 450-ns access time) can cause instability in the Port-A-Matic's display. That's because the mas- ter enable signal isn't issued until IC1 1 has approved the port address, but the computer doesn't wait around patiently until that judgment is made. If the EPROM is too slow and the computer is too fast, the master enable signal could be issued just as the computer was beginning another f/O opera- tion. That would cause the Port- A-Matic's display to change to a second address after showing the one that triggered it in the first place. The second address is usually related to something like an interrupt request. RAM refresh, and so on. The problem can be elimi- nated by using a faster EPROM for IC11. There's no hard and fast formula for calculating how fast an EPROM you should use, but if the problem shows up, you can clear it up by switching to a different EPROM. The fastest 2716 that's easily available is a 2716-1, with an access time of 350 nanose- conds. If that's still too slow, you could switch to a 2732A, since they're available with access times as low as 200 nanose- conds, which should be fast enough for even a real screamer personal computer like a 33- MHz 386 machine. You can plug a 2732 directly into ICll's socket, but the look- up table must be burned into tire top half of the EPROM, since the extra address pin is tied high on the board. two-bit section of IC5, the buffer that handles A8 and A9, will be disabled. When the first digit is enabled. IC7 is enabled, IC5 is disabled, and the lower four address lines are routed to the character gener- ator and the display When the second digit is lit, IC5 remains disabled, and IC7 sends the sec- ond group of address lines (A4— A7) to the character gener- ator. When the last digit is lit, IC7 is disabled and IC5 is enabled, thereby causing the signals from A8 and A9 to be routed to the character generator through Dl and D2. The two diodes are needed to isolate the outputs of the two-bit section of IC5 from the outputs of IC7. That arrange- ment is necessary because the 4040 runs constantly, whether or not the Port-A-Matic has detected a valid I/O address. If the diodes weren't there and the outputs of the two-bit part of IC5 were connected directly to the inputs of the character gener- ator, the A8 and A9 inputs of the port selector EPROM would see data from both IC5 and 1C7. That might also cause it to ignore a valid address and okay an invalid address. LED selection One really useful feature of the Port-A-Matic is its ability to as- sign a particular LED to a par- ticular port address. It's a lot easier to see what your computer is doing by having the Port-A- Matic light an LED you've la- belled COMl than waste some brain space by remembering that COMl is assigned to port 03F8h. The LED assignments are made in the EPROM look-up table. If a valid I/O address shows up on the bus, the EPROM enables the con- trol circuitry and also sends the stored LED number to IC14. a 74LS154 four-to-sixteen line data selector. When the master enable signal shows up at IC14's enable inputs (pins 18 and 19), one of IC14 s outputs will go low. thereby triggering a one-shot that lights the corresponding LED for half a second. All of the one-shots are built using 558 quad timers. The 558 has open-collector outputs, so pull-up resistors (R63-R78) are used on all outputs. Two additional LED's, LED1 and LED2, indicate I/O activity. Tor and Tow, respectively. The LED's are controlled by separate halves of IC9, a 556 dual timer. The I/O activity data is stored in the two-bi t section of IC4 ( D4 and D5): when the master enable sig- nal appears, that data is passed to the input pins of IC9. Since Tor and Tow from the bus are both active low, and only one can be active during a given I/O opera- tion, a single low will be sent to the corresponding half of IC9. The master enable signal trig- gers a similar one-shot (IC8-a), whose output pulse enables IC12, the 74LS138 that multi- plexes the three display digits. The Port-A-Matic sends data to the display circuit constantly, but the digits themselves are only illuminated when the master en- able signal triggers IC8-a. The three one-shots (IC8-a and both halves of IC9) are quite sim- ilar. The transistors that control their inputs let an input trigger interrupt the one-shot's internal timing. The one-shot (IC8-a) control- ling the display multiplexer is more responsive than the ones in IC9 because IC8-as reset input (pin 4) is also controlled by the master enable signal. Every time a new I/O address is validated by PARTS LIST Resistors ^^hm^^^^^^^^^h .411 resistors are 'A-watt, 5%. unless otherwise noted. Rl, RIO, R12-R30 2200 ohms R2, R4, R7 5600 ohms R3 J megohm R5, R8, R31-R46 560,000 ohms R6.R9, R47-R62 160 ohms Rll 470ohms R63-R78 1000 ohms Capacitors m ^^^ ma ^^ m ^^ m ^^ CI, C2, C10-C14, C16, C38 0.1 m-K monolith tc C3 , 0.001 \lF, silver mylar C4, C6.C8, C19-C22. C24-4:26, C29-C32, C34-C37 , 0.47 jlK 35 volts. Tantalum C5. C7, C9, CIS. C17, C18, C22, C28, C33 0.01 i*.F. monolithic Semiconductors i ici IC2 .74LS02 quad NOR gate .74LS00 quad NAND gate IC3 74LS74 dual D Jlip-Jlop IC4.IC5 74LS367hex buffer IC6 74LS373 octal D latch IC7 74LS257 quad 2- input multiplexer IC8.IC9 '.. 550 dual timer IC10 2716 EPROM 2K X 8. 450 ns IC11 2716EPROM2k X 8, see text for speed IC12 74LS138 l-of-8 decoder 1C13 4040 binary ripple counter IC14 74XSJ54 4-to-16 line decoder IC15-IC18 558 quad timer Dl, D2 1N914 small- signal diode LED1 yellow light- emitting diode LED2 green light- emitting diode LED3-LED18 .red Ught-emltting diode DISP1-DISP3 FND5O0LED display, common-cathode Q1-Q6 2N3906 small- signal PNP transistor ORDERING INFORMATION A set of two double-sided printed circuit boards is avail- able for $38.95 from Systems 80 Instruments Ltd., c/o CF Liebert, Inc., P.O. Box L, Blaine, WA 98230. The two programmed EPROMs (2716-1, 350 ns) as described in the article are also avail- able from Systems 80 for $19.95. All prices include shipping and handling. the port selector EPROM, the master enable signal will reset the one-shot. The look-up table As mentioned before, the lower eight address lines are handled in a straightforward manner, so we can be sure that they will al- ways be properly sent to the lower eight address pins of the port se- lector EPROM. But there's noway to tell what data will be at the EPROM's two upper address lines (A8 and A9, pins 23 and 22). But since we're dealing with digital data, it's misleading to say that the data there will be indetermi- nate. Actually, there are only four possibilities, zero through three. And we've already seen that con- fusion will exist only the first time the address shows up on the bus. The reason that's not signifi- cant is that most I/O operations involve accessing the same port over and over. The trick to cor- rectly decoding the upper two ad- dress lines is to make sure we take all the digital possibilities into account when we build the look-up table. For example, suppose we want to decode port 03F8h, and that we want to assign it to LED 12. If there was no problem with the address lines, we would put a OCh at location 03F8h in the EPROM. When the port is ac- cessed, the low state of bit 7 will enable the rest of the control cir- cuitry and the C in the lower half will be passed on to IC14, so LED 12 will light up. £ In order to make that happen, ^ regardless of what data is present > at the EPROM's A8 and A9 inputs < during the first access of port KK.3£ 80 ns 300.00 1 SIMM) 1Mx9 80 ns 122.00 1 SIMM' 1 ' 1 256Kx9 100 ns 35.00 1Mbit IMxl 100 ns 11.251 41256 256Kxi 60 ns 4.951 41 256 2S6KX1 80 ns 3.95 1 41256 2S6Kxi 100 ns 2.80 1 141256 256Kxi 120 ns 2.651 U464 .--:■....; 120 ns 3.75 1 41264 m 64Kx4 100 ns 7.95 1 EPROM 27C1000 128KxB 200 ns 520.751 2751 2 64Kx8 200 ns 7.80 1 27256 32K*8 150 ns 6.50l 27128 i6Kx8 250 ns 4.25 1 STATIC RAM [62256P-10 32KkB 1O0ns S12.95I I6264P-12 eKxfl 120 ns 4.851 I6116AP-12 2Kk8 120 ns 4,50j OPEN EVi DAYS. 7 » in 10 m SHIP VIA FED-EX ON SAT SAT DELIVERY INCLUDED ON. FED-EX ORDERS. RECEIVED br MasterCard VISA or UPS CASH COO MICROPROCESSORS UNLIMITED, INC. sSSsSf (918)267-4961 No fnjnlmurd &rd*r, FS*u an pnmnttKlbdwv CIRCLE 61 ON FREE INFORMATION CARD would make it impossible for you to decode two ports whose ad- dress differs only in the upper digit— 02F8h and 03F8h. for ex- ample. Not true. Remember that the reason for putting the same data at four lo- cations in the look-up table is to be certain that the master enable signal will be generated no matter what data is present at the EPROM s A8 and A9 lines the first time a port address is put on the computer bus. Since the control circuitry only cares about the state of the EPROM's D7 line, the GET PING Getting Th« THE MOST ™£ f,,mYour FROM YOUR PRINTER BPT81 — It is probable that 80% of dot-ma- trix printer users only ever use 20% of the features offered by their printers. This book will help you unlock the special features and capabilities that you probably don't even know exist. To order your copy send $6.95 plus $1 .50 for shipping in the U.S. to Elec- tronic Technology Today Inc., P.O. Box 240. Massapequa Park, NY 11762-0240. master enable signal will be pro- duced whenever that line is low. The EPROM data in the lower four bits only determines which LED will light up. So, for example, if you wan ted any access of port 02F8h to light LED3, and any access of port 03F8h to light LED 12. you would store 03h at EPROM location 02F8h and OCh at EPROM loca- tion 03F8h. The values at 0F8h and lF8h can be anything as long as the high bit is low. Unfortunately, we're out of space. See you next time>CD| WORKBENCH continued from page 83 CO o z D cc LJJ —I HI 6 Q < if vanced versions of Slick!. Every- thing described so far, (and more), is part of the basic $95 version. The other versions do still more. Slick! can use all the standard display cards that are supported by AutoCAD (CGA. EGA. VGA, and Hercules), and has simple command-line switches to di- rectly support higher screen res- olution with more than fifty other video cards. The Level-2 version of Slick! will also support any ADI display driver. If you run Auto- CAD with an ADi driver. Slick! Level-2 will give you the same on screen resolution as AutoCAD. The Level-3 version of Slick! ($195) won't support ADI dis- plays, but it will print your draw- ings (or slides) on either an HP Laserjet or an Epson-compatible printer. The prints aren't just screen dumps — the program does the same type of vector to raster conversion that AutoCAD does when it prints a file. Slicks printer setup screen lets you set the plot origin, size, and orienta- tion, and can send the result to either the printer for a hard copy or a file for storage. The top-of-the-line version of Slick! is Level-4 ($250), and that one has both the ADI and printer options. You can run Slick! from the DOS prompt, but the real power of the program becomes evident by running it while you're still working in AutoCAD. The man- ual shows you how to modify the ACAD. PGP file so you can run SLICK directly from AutoCAD's command line, and being able to scroll through a directory of blocks means that you don't have to remember the difference be- tween TRANS385.DWG and TRANT385.DWG— you can see it on the screen. Slick! works extremely well, saves a lot of time, and CAD Sys- tems Unlimited is a great compa- ny to deal with on the phone. If you only have the bucks to buy a single AutoCAD accessory, Slick! 's the one that you must get. It's by far the most useful CAD utility that you can possibly own. — Robert Grossbiatf>CD$ 90 DRAWING BOARD continued from page 80 determine both the hue and sat- uration of the colors displayed on theTV. The two elements, hue and saturation, are usually referred to as "chrominance" or "chroma." A separate colorburst signal is sent for each line of video and they're all exactly in phase with each other. That's obvious if you realize that inconsistencies would result in color shifts from line to line. {That might make for some interesting pictures, but it's not the kind of stuff sponsors shell out bucks to transmit.) The picture information imme- diately follows the back porch and, for the next 52 microseconds or so, the electron beam travels across the screen painting a line of varying color and brightness. The color you see depends on the rela- tive phase difference between the video signal and the colorburst signal in the back porch. The brightness, referred to as the "lu- minance," is simply a function of the voltage level. If you look at the voltage scale on Fig. 1, you can see how the volt- age varies during a line of video. NTSC video calls for a peak-to- peak signal voltage of 1 volt but, instead of volts, the video signal is usually referred to in IEEE (In- stitute of Electrical and Electronic fngineers), or IRE (Institute of Radio fngineers) units. That scale divides the 1-volt range into 140 parts with zero-IRE corresponding to about 0.3 volts. The full scale goes from -40 IRE to +100 IRE units. When you hear a person re- fer to 50 units of video, they're using the IRE scale. The reason things are done like that is that there has to be some way to distinguish between con- trol signals and picture informa- tion. The NTSC solution was to reserve the area from to 0.3 volts for the control signals and the rest of the space (0.3 to 1 volt) for pic- ture. If the luminance is at0.3 volts orO IRE, the picture will be black — 100 IRE will give you white. Every- thing in the middle will be seen as varying shades of gray or color. The area below IRE is usually re- ferred to as "blacker than black." Once the end of the picture in- formation is reached, the electron beam is turned off for about 1.5 microseconds (the front porch), and then a horizontal sync pulse is sent. The location and duration of the pulse (4.7 microseconds) is critical to proper placement of the horizontal line on the screen since that causes the electron to move back to the right side of the screen and start a new line. Messing around with the hori- zontal sync is a popular activity with the people who dream up ways to scramble TV pictures. If the pulse isn't there at exactly the right time, the television set has no way to identify the start of a new line of video. As a result, the TV will do horizontal retraces at somewhat random intervals and instead of watching a recently re- leased movie, you'll be looking at some images that really belong on a variable interossiter (and how many of you know what that is?). When we get together next time, we'll talk about vertical sync and start to design some video hardware. U should be fun. R-E Try the Electronics bulletin board system (RE-BBS) 516-293-2283 The more you use it the more useful it becomes. We support 300 and 1200 baud operation. Parameters: 8N1 (8 data bits, no parity, 1 stop bit) or 7E1 (7 data hits, even parity, 1 stop bit). Add yourself to our user files to increase your access. Communicate with other R-E readers. Leave your comments on R-E with the SYS0P. RE-BBS 516-293-2283 TURBOSPORT 386 PORTABLE LAPTOP COMPUTER 40 MB Hard * S03S6 32 bit processor, 12/6 MHz (switchable). ■ 40 MB (aams.i hard drive, « One 3,5" 1.4 MB floppy disk drive. * 2 MB RAM. ♦ 100% IBM compatible. ■ "Page-While" fluorescent backlit LCD display, 10.5" viewing area. ■ MS-DOS 3.21 induded. ■ Supports: MS OS/2 version 1,0 h Xenix, ano" also Microsoft Wmdows/3B6 environ merits. ■ Zero wail slate. ■ Socket for B03S7 numeric co-processor. * Internal Hayes £400 baud modem. ' Serial and parallel printer ports. * Resolution: 640 x 400 pixels. * 79-key lull function detachable keyboard. * Real time clock and calendar. * AC adapter. * "Fast" charge NiCad battery pack included. •Dim- 13.25"Wx 14.75"D* 4.75 H H, ■ Weight: 14,7 lbs ■ One Year Warranty! FACTORS NEW! Due to a special ar- rangement, we were able 1o obtain a large i riven lory of these portable com- puters. As a result, we cam now olfer them to you at HUGE SAVINGS! FAC TORV_PERPEj^ Manufacturers Suggested Retail s 2999 Item No B-1515-126686 Insured Ship/Hand; $19.00 | FOR FASTEST SERVICE CALL TOLL FREE 1-800-729-9000 MasterCard | ^ J RUSH DELIVERIES ONLY ftfrr $6.95 plus normal S H . Ask an Joperalor to "SHIP IT FED EX® Delivery Service!" DA MARK INTERNATIONAL, INC- S7Q7 Sturwgie Creek Parkway. Minneapolis, UN 554-M Guste-mer Service ■ 6t2-&56-4g40 Please rush me: Zenith Laptop Computer(s) | @S2999each h plus $19,00 Breach. Item No B-1 515-1 28536 MN res. add 6% sales tax. Nam&_ City,State.Zrp D Check/MG D VISA □ Masiar Card Q Discover Card No.. E*p Dale Siflnatufe _Ph,*( r- DELIVERY TO 48 U.S. STATES ONLY 91 MARKET CENTER w o z o tr i- o lit o D < FOR SALE PHOTO FACT folders, under #1400 $4.00. Others $6.00. Postpaid. LOEB, 414 Chestnut Lane, East Meadow, NY 11554. GREAT buys! Surplus prices, ICs, linears, transfor- mers, PS, stepping motors, vacuum pump, pho- totransistor, meters, LSASE, FERTIK'S, 5400 Ella, Phila., PA 19120. DESCRAMBLERS. All brands. Special: Combo Jerrold 400 and SB3 S165. Complete cable de- scrambler kit $39. Complete satellite descrambler kit $45. Free catalog. MJM INDUSTRY, Box 531, Bronx, NY 10461-0531. /CABLE-TV AT ITS BEST V SCIENTIFIC ATLANTA: i Models 850O85S0-85S0 . $275.00 p SA-3 [Add-On Descrambler] . S 99.00 ie JERROLD; ot SB-3 [Inband Gated Sync| . . .$ 74.00 oz TRI-BI |Trimode/Bistale .... S 95.00 a a OAK: M-35B ICombo W/Vari-sync] . . S 99.00 N-1J |Add-On W/Vari-sync| . , . S 89 00 Zi° HAMLIN: a M L D- 1200| Ad d-OnJ . S 89.00 ZENITH: [Z-TAC Descrambler £169.00 CONVERTERS: [SO-Crtannels .$ 95.00 N °2 AC CO N.A.S. INTERNATIONAL (BOO) 726-4.NAS TUBES: "oldest," "latest." Parts and schematics. SASE for lists. STEINMETZ, 7519 MaplewOOd, RE, Hammond, IN 46324. LASER Listener II, other projects. Surveillance, descrambling, false identification, information. Plans, kits, other strange stuff. Informational pack- age $3.00 refundable DIRIJO/BOND ELEC- TRONICS, Box 212, Lowell, NC 28098. ENGINEERING software, PC/MSD0S. Hob- byists — students — engineers. Circuit de- sign $59.00, FFT analysis $69.00, mathe- matics $49.00, logic simulation $49.00, circuit analysis $29.00. Free catalog, (614) 491-0832, BSOFT SOFTWARE, 444 Colton Rd„ Columbus, OH 43207. RESTRICTED technical information: Electronic surveillance, schematics, locksmithing, covert sci- ences, hacking, etc. Huge selection. Free bro- chures. MENTOR -Z, Drawer 1549, Asbury Park, NJ 07712. MICROWAVE TV RECEIVERS 1.9 to 2.7 GHz □ 2 CH Compact Disti System -£77.95 5 CH Dish System - 593,95 12 CH fagi (Rod) System - $12395 30 CH Dish System -S 163.90 Y"agi-S1B3.90 SUN MICROWAVE INTL. INC. Send SI ■ for P.O. BOX 34522 catalog on these PHOENIX. AZ B506J and other line |50Z] 230-0640 video producls. VISA/MC/COB QUANTITY DISCOUNTS LIFETIME WARflANTY CABLE TV converters bargain headquar- ters: Zenith, Tocom. Scientific Atlanta, Hamlin. Jerrold 400-DRX3DIC w. remote $135, Oak M35B $60.00. Quantity discount. Visa-M/C-COD. Order yours today. 1 (800) 327-8544. STEPPER motor drive & control with Commodore 64. Affordable hardware, interface, & software. Send for detailed literature & prices to: MASE, R.D. #2 Box 166, Mohrsville, PA 19541. T.V. tunable notch filters. Free brochure. D.K. VID- EO, Box 63/6025. Margate, FL 33063. (305) 752-9202. SURPLUS ELECTRONICS. New giant wholesale catalog. Hundreds of amazing bargains. $2. Box 840,Champlain,NY12919. CLASSIFIED AD ORDER FORM To run your own classified ad, put one word on each of the lines below and send this form along with your chock to: Radio-Electronics Classified Ads, 50O-B Bi-County Boulevard, Farmingdale, NY 11735 PLEASE INDICATE in which category of classified advertising you wish your ad to appear. For special headings, there is a surcharge of $25,00. ( ) Plans/Kits ( ) Business Opportunities ( ) For Sale ( ) Education /Inst ruction ( ) Wanted ( ) Satellite Television ( ) Special Category: $25.00 PLEASE PRINT EACH WORD SEPARATELY, IN BLOCK LETTERS. (No refunds or credits for typesetting errors can be made unless you clearly print or type your copy.) Rates indicated are for standard style classified ads only. See below for additional charges for special ads. Minimum: 15 words. 1 6 11 16 ($49.60) 21 ($65.10) 26 ($80.60) 2 7 12 17 ($52.70) 22 ($68.20) 27 ($83.70) 13 14 16 ($49.60) 17 ($52.70) 18 ($55.80) 19 ($58.90) 20 ($62.00) 23 ($71.30) 28 ($86.80) 24 ($74.40) 29 ($89.90) 5 10 15 ($46.50) 20 ($62.00) 25 ($77.50) 30 ($93.00) 31 ($96.10) 32 ($99.20) 33 ($102.30) 34 ($105.40) 35 ($108.50) We accept MasterCard and Visa for payment of orders. If you wish to use your credit card to pay for your ad fill in the following additional information (Sorry, no telephone orders can be accepted.): Card Number Expiration Date Please Print Name Signature IF YOU USE A BOX NUMBER YOU MUST INCLUDE YOUR PERMANENT ADDRESS AND PHONE NUMBER FOR OUR FILES. ADS SUBMITTED WITHOUT THIS INFORMATION WILL NOT BE ACCEPTED. CLASSIFIED COMMERCIAL RATE: (lor firms or individuals offering commercial products or services) $3.10 per word prepaid (no charge for zip code).. .MINIMUM 15 WORDS. 5% discount for same ad in 6 issues; 10% discount for same ad in 12 issues within one year; if prepaid. NON-COMMERCIAL RATE: (for individuals who want to buy or sell a personal item) $2.50 per word, prepaid, ...no minimum. ONLY FIRST WORD AND NAME set in bold caps at no extra charge. Additional bold lace (not available as all caps) 55e per word additional. Entire ad in boldface. $3.70 perword TINT SCREEN BEHIND ENTIRE AD: S3.B5 per word. TINT SCREEN BEHIND ENTIRE AD PLUS ALL BOLD FACE AD: $4.50 per word. EXPANDED TYPE AD: S4.70 perword prepaid. Entire ad in boldface, $5.60 per word. TINT SCREEN BEHIND ENTIRE EXPANDED TYPE AD: $5.90 per word. TINT SCREEN BEHIND ENTIRE EXPANDED TYPE AD PLUS ALL BOLD FACE AD: $6.80 per word. DISPLAY ADS: 1" x 2 W— $385.00; 2" x 2 W— $770.00: 3" x 2'A" — $1155.00. General Information: Frequency rates and prepayment discounts are available. ALL COPY SUBJECTTO PUBLISHERS APPROVAL. ADVERTISEMENTS USING P.O. BOX ADDRESS WILL NOT BE ACCEPTED UNTIL ADVERTISER SUPPLIES PUBLISHER WtTH PERMANENT ADDRESS AND PHONE NUMBER. Copy to be in our hands on the 10th of the third month preceding the date of Ihe issue, (i.e., Aug. issue copy must he received by May 10th). When normal closing date falls on Salurday, Sunday or Holiday, issue closes on preceding working day. Send for the classified brochure. Circle Number 49 on the Free Information Card. 92 CB RADIO OWNERS! We specialize m a w ide variety ol lech meal informal ion, pars an d services for CB radios, 10-Metet and FM conveision kits, repair books, plans, high-performance accessories. Thousands of satisfied customer since 19761 Catalog $2. CBC INTERNATIONAL P.O. BOX 31500RE, PHOENIX, AZ 85046 FEB 87 Tri parts $59.00. Feb 84 SB parts 549.00. $3.50 shipping. OCTE, Box 276, Alburg, VT 05440. (514) 739-9328 RENTAL movie stabilizer. Conned between VCFts or to monitor. Satisfaction guaranteed. $69.95. $4.00 handling 1 (800) 367-7909. CABLETV des cram biers, Jerrold, Scientific Atlan- ta, Zenith, most major brands. Dealer inquiries wel- come. Visa-M/C accepted. E & O VIDEO, 9691 E. 265th Street, Elko, MN 55050. 1 (800) 638-6898. TEST equipment pre-owned now at affordable prices. Signal generators from $50.00. Os- cilloscopes from $50.00. Other equipment, includ- ing manuals available. Send for Catalog. J.B. ELECTRONICS, 3446 Dempster, Skokie, IL 60076. (312) 982-1973. BEST BY NAIL Rates; Writs National, Box S, Sarasota, Ft 34J30 FREE STAMPS WITH approvals. Aldinger, Box 6061(RE), Minol, N.D. 58702. HELP WANTED CRUISE SHIP JOBS. Hiring: Men-Women S300-S900 Weekly, Plus World Travel. Hawaii, Caribbean, South Pacific. Call Now 1 1(206)736-7000. Exi. 900 N. MONEYWAklMG OPPORTUNITIES EARN $2,000 PER 1.000 envelopes you process at home. Easy plan. Free information send sell-addressed stamped envelope' Lincoln Enterprises, FOB 752209, Houston, TX 77275-2209. EARN BIG PROFITS buying seized vehicles, jewelry and homes. Examples: 1985 Porsche $3,900, 22' boat 11,400. 3 bedroom home J1 7,000. Buyers Guide: 1-800-727-7699. Box 2000. PERSONAUMISCELLANEOUS LONELY? FREE SINGLES Lists! $1.00: Publishing, Box 24618(RE), Detroit, 48224. CABLE TV converters: Jerrold, Oak, Scientific At- lantic, Zenith & many others. "New MTS" stereo add-on: mute & volume. Ideal for 400 and 450 owners! 1 (BOO) 826-7623, Amex, Visa, t*C accept- ed. B & B INC., 4030 Beau-D-Rue Drive, Eagan, MN 55122. DESCRAMBLERS, Oak remote $165.00, Tri-Bi $89.00, SA-3 $99.00. MLD 1200 S55.00 - 10 for $450.00, remote Pioneer S199.00, Pioneer add on $129.00, M35B $65.00, Jerrold 400 $135.00. Mag- navox converler w/r $45 00, Tocom Remote S199.00, same day shipping, COD ok. MOUNT HOOD ELECTRONICS, (206) 896-6837. ELECTRONIC test equipment, laboratory equip- ment, — surplus and priced to go! Catalog $1.00. LEHMAN, R.D. 1 Box 580, Wrightsville, PA 1736S PARABOLIC reflectors 18 spun aluminum dish focuses RF, light, sound. $25.00: PJC, 2981 Tess Ave., Granger, UT 84119. FAMOUS "RRESTIK" BRAND CB ANTENNAS AND ACCESSORIES. QUALITY PRODUCTS FOR THE SERIOUS CB'er. SINCE 1962 FIRESTIK ANTENNA COMPANY 2614 EAST ADAMS PHOENIX. ARIZONA 85034 UNIVERSAL couplings to correct shaft misalign- ment. Insulated, available in two sizes, inexpensive. JACKSON BROTHERS, Box 632, Paramus, NJ 07652. (201) 967-1309. MINIATURE electronics iike James Bond, Catalog $3.00, refundable. F & P ENTERPRISES, Box 51272. Palo Alto, CA 94303-L. CABLE-TV BONANZA! ITEM HAMLIN MCC 3000 36 CURDED REMOTE CUNVEFtlER iCn PANASONIC WIRELESS CONVERTER IQnr Scttbiiyl STAR GATE MO ■JERROLD 400 COMBO JERROLD J0O HAND REMOTE CONTROL ■JERROlO 450 COMBO ■JERROLD 450 HAND REMOTE CONTROL JERROLD SB-ADO-OM "JERROLD SB-ADD-ON WITH TRIMO0E 'M-35 B CQMBO UNIT [Gh 3outpu1 only. 'M-3SB COMBO UNIT WITH VARISYNC 'MINtGQOE |N-I2i MIMICQDE lNl2i WITH uAfllSVNC ■MINICODE VARISYNC WITH AUTO ON-OFF ECONOCODE im,n,cod«? surtsMNTi."! ECONOCODE WITH VARISYNC ■MLD-120O-3 iCr, 3oii1piiU ■MLD- 1200-2 iCn 2 aulpir ■ZENITH SSAVI CABLE READY INTERFERENCE FILTERS iCn 3pnly, 'EAGLE PD-3DESCRAMBLER iCh :irml[h,l i>nly, -SCIENTIFIC ATLANTA ADD ON BEfL ACEMENT 3ESC«AMUL£H 10 OR MORE ■CALL FOR AVAILABILITY Name Address . State _City_ D Cashier's Check Acct * .Zip D Money Order .Phone Number ( J □ COD □ Visa Exp. Date Quantity Item Output Channel Price Each TOTAL PRICE SUBTOTAL from shipping any cable descrambling unit to anyone residing in the state of California. Prices subject to change without notice. Shipping Add $3.00 per unit COD & Credit Cards — Add 5% PLEASE PRINT TOTAL O Mastercard o Signature FOR OUR RECORDS; DECLARATION OF AUTHORIZED USE — I. ire undersigned, do hereby declare under penalty of penury thai all products purchased, now and in (he fulure, will only be used on cable TV systems with proper authorization from local officials or cable company officials in accordance with all applicable federal and state laws. FEDERAL AND VARIOUS STATE LAWS PROVIDE FOR SUBSTANTIAL CRIMINAL ANO CIVIL PENALTIES FOR UNAUTHORIZED USE. Dated:. _Signed:_ Pacific Cable Company, Inc. 7325V2 RESEDA BLVD., DEPT. FM ■ RESEDA, CA 91335 (818)716-5914 • No Collect Calls • (818)716-5140 IMPORTANT: WHEN CALLING FOR INFORMATION Please have the make and model # ol the equipment used in your area. Thank You > c > ■< _ ¥. W HnnlinMLD-1200 SW.95 S62.0O Z ^ J £ OikN.lIW/V.S 599.95 S62.00 O < £! Oik-M-35-B W/V.S 599.00 578.00 I t O *J OAKE-13.™ 599.95 558.00 t— Q W S Zenith SSAV1 51SS.00 5145.00 O |— \H < Eagle PD-3 5120.00 585.00 H **■ fc Scientific Admti 5129.95 5105.00 Qj 2 S ¥1 SA-Combo'* CALL SCU1 . —I W I Tocom. ...... 5350.00 5295.00 Q ^ g h C)»kN-12W/Auta 5140.00 5105.00 ^ >^ Z Jendd Staraoni CSV.... 5139.95 Oil *NEW STARGATE 2000 CABLE CONVERTER 1 -$89.00 10-S69.00 100-Call Lasl channel recall-Favorite channel select- 75 channel-Channel scan- Manual fine tune- One year warranty-surge protection- HRC & Stand- ard switch able- and much more. Call Ttxliw! INFORMATION(402)554-041 7 Orders Call Toll Free 1-800-624-1150 M.D. ELECTRONICS 115 NEW YORK MALL SUrTE 133E OMAHA. NE. 68114 M.C. VISA REMOVE VOCALS FROM RECORDS AND CDs! ctHI sing With The World's Best Bands! An (J i (limited supply of Backgrounds From standard stereo records! Record with your voice or perform live with the backgrounds. Used En Pi of essi ona I Performance yet connects easily to a home component stereo. This unique product Is manufactured and sofd Exclusively by LT Sound - Mot sofd through dealers. Call or write for a Free Brochure and Demo Record. LT Sound, DepLR L-3 ,7980 LT Parkway Lithon la, GA 3005 8 (404) 482-4724 Manufactured and Sold Exclusively by LT Sound HaimaiMimuaaaiiumiamaataaigaicia ' ACCEPTING new customers again for our monthly picture flyer. Lots of qualily surplus electronic parts at low prices. STAR-TRONICS, PO Box 683, McMinnville, OR 97128. CABLE boxes, 400 w/r $1 35.00, RTC-56 $169.95, SA-3 $99 95, Tocom w/r $199.00, Hamlin 1200 $45.00, Pioneer add on with free remote converter $199.00, M3EB $55.00, TriMode $99.00, 90 day warranty, COD. welcome. G.D. ELECTRONICS, (602)859-9441. DIAL drives for fine tuning variable capacitors and potentiometers. Reduction ratios up to 10:1 avail- able. JACKSON BROTHERS, Box 632, Paramus, NJ 07652. (201) 967-1309. INDUCTORS! Lowest prices available, immediate delivery on all types. ELTECH SALES, INC., 286 Colby Place, Paramus, NJ 07652. (201) 967-1309. RECEIVE absolutely free 50 technical magazines! Complete details $5.00. BALL, PO Box 1078-RE, Snellville, GA 30278-1078. NEW HE NE LASER TUBES $35 Dealer Inquiries Invited. Free Catalog! MEREDITH INSTRUMENTS: 6403 N. 59th Ave. Glendale, AZ 85301 * (602)934-9387 "The Source for Laser Surplus" TJ Services is serving you! Quality products, de- pendable service, knowledgeable sales people and low prices prove it! Not sure what you need? Call {313) 979-8356, fax: (313) 795-4329. Prices quoted are: 20/10/5/1 lot. Jerrold Data Reading Trimode combo wireless remote $109/$119/$129/$139. DRX-3-DIC $69/$79/$89/$99. DRZ-3 $49/$59/$69/$79. Tri-Bi-2 or 3 $69/$79/$89/$95. SB-3 $45.00 each. Oak M35B starting at $20 each. Original N-12-3VS $65 each. Scientific Atlanta type add-on $69/$79/$S9/$109. Combo's - call. Hamlin CRX-66003M$89/$99/$l09/$125.CRX-6600-2 $39/$49/$59/$69. MLD-1200-2 or 3 $29/$39/$49/$59. Eagle PD-3 original $59/$64/$99/$109. Interferance Filters, we stock all channels $12/$15/$18/$30. Pioneer type add- on $79/$89/$109/$129. Replacement remotes for most converters - call Many accessories and parts in stock. COMMUNICATIONS. Electronic equipment, sales, service, FCC licensed, free catalog. RAYS, PO Box 14862, Fort Worth, TX 76117-0862. T.V. converters, Tocom w/r, SA3, 400 w/r, M35B, RTC-56, MLD 1200, Pioneer w/r. Pioneer add on, Z- Tac, all at wholesale prices, example — Tocom with remote $199.00 or 5 for $175.00 each, TriMode $89.00. S.A.C., (702) 647-3799. AUTO security— american made NU-1 Auto Alarm Simple installation instructions. Complete system $58.89 plus $4.50 S/H. P.D. & F, Box 10281 , Killeen, TX 76542. IS it true... Jeeps for $44.00 through the govern- ment? Call for facts I (708) 742-1142 Ext. 4673. PRIVACY problem — need information? New elec- tronics surveillance, debugging, protection catalog $5.00. Assembled — kits. TECHNOLOGY SER- VICES, 829B Ginette Street, Gretna, LA 70056. TUBES - 2000 TYPES DISCOUNT PRICES! Early, hard-to-find, and modern lubes Also transform &rs, capacitors and parts for tube equipment. Send $2.00 for 24 page wholesale catalog. ANTIQUE ELECTRONIC SUPPLY 688 W. First St.-Tempe, AZ 85281 '602/894-9503 PLANS AND KITS BUILD this five-digit panel meter and square-wave generator including an ohms, capacitance and fre- quency meter. Detailed instructions $2.50, BAG- NALL ELECTRONICS, 179 May, Fairfield, CT 06430. DESCRAMBLING, new secret manual. Build your own descram biers for cable and subscription TV. Instructions, schematics for SSAVI, gated sync, sinewave, (HBO, Cinemax, Showtime, UHF, adult) $8.95, $2,00 postage. CABLETRONICS, Box 3050 2R, Bethesda, MD 20814. 450 MHz Spectrum analyzer - kit - $459.95 or assembled S tested $799.95. For more information, send legal size SASE to A & A ENGINEERING, 2521 W. LaPalma. #K, Anaheim, CA 92301. REMOTE CONTROL KEYCHAIN Complete w/mini-transmitter' and +5 vdc RF receiver Fully assembled including plans to build your own auto alarm Quantity discounts available Check, Visa or M/C'i GM n nc ^necK,visa vj> I y.aO Add $ 3 shipping VlSITECT INC./Dept, R (415): 872-01 2S PO BOX 5442, SO, SAN FRAN..CA. 94080 Projection TV. Convert your TV to project 7 fool picture,,. Easy... Results comparable to $2,500 proj- ectors... Plans and 8" Lens $24.95... Professional systems available... Illustrated catalog free.,, MACROCOMA, 15GE Main Street, Washington Crossing, PA 18977. Creditcard orders 24 Hrs. (215) 736-3979. ALARM kit for home, 12vDC, delay and in- stantaneous loop. Includes board and components, $47.50 + $3,50 S&H. For purchase or free info: K.E.P., PO Box 830123, Stone Mountain, GA 30083. RADIO Astronomy! Monlbly magazine, books, components. $3.00 brings sample package. BOB'S ELECTRONIC SERVICE, 7605 Deland, Ft. Pierce, FL 34951. CATALOG: hobby/broadcasting/HAM/CB: Cable TV, transmitters, amplifiers, surveillance devices, computers, more! PAN AXIS, Box 130-F1, Paradise, CA 95967. SURVEILLANCE equipment design gives 58 schematics of Sheffield Electronics' sui veillance de- vices. Circuits explained. Transmitters range from pens 10 one-mile VOX'S including crystal, subcarrier, carrier current, infrared, firefly, automobile. Demod- ulators given. Cube lap and duplex mains powered transmitters presented. Eighteen telephone trans- mitters are leech and battery types including crystal and subcarrier. Countermeasures chapter. Much more. This 81/2x11 inch 110-page book is illustrated with photographs. Price $30.00 + $4.00 S&H. First class mail U.S. & Canada. Overseas Airmail S&H $9.00. One-day processing, pay with Money Order or Cashier's Check. Send to: WINSTON AR- RtNGTON, 7223 Slony Island Ave.. Chicago, IL 60649-2806. CIRCLE 53 ON FREE INFORMATION CARD Mfflffl DETAILED PLAHS: 17. (S TV-SCOPE PEHN RESEARCH, BOX 3543 pHlllMSjMrt, PA 17701 At Interesting and worth- while project. This EASY- TO-BLULD circuit lets you use any regular TV set as i s Imp la OSCILLOSCOPE. No modifications to TV! Tiny, 9v battary powered. Goes anywhora! Order now! Ask for our FREE CATALOG of other plana and kits! STEREO FM transmitter!. Transmil your VCR/CD/ Walkman to any FM stereo radio. One chip does it all! Free schematic and info. Send a self addressed/ stamped envelope to: DJ INC., B47A Second Ave.. Suite 113. New York. NY 10017. __ FM transmitter 88 to 108 MHz kit $12.95; power supply to 20 V 1 AMP kit $79.99; Flyback tester assembled $95.99; shipping and handle 4% unit. SASE for information. SIERRA ELECTRONICS, PO BOX 709. Elfers, FL 34680-0709. ELECTRONIC kits! Transmitters! Recorders! Phone devices! Bug detectors! Surveillance items! More! Catalog $1.00; XANDI ELECTRONICS, Box 25647, 60Y, Tempe, AZ 85285-5647. BUILD the "Invader," common construction mate- rials, electronic kits available, complete robot ptans $11.95, details free, ROBOT WORkS, Box 1979, Colorado Springs. CO 80901 . COMMODORE-64 RS232 interface. Plans S5.00. PCB and components available. Details free. HITECH INDUSTRIES, P.O. Box 690925, Tulsa, OK 74169. __ SECURITY schematics, transistor, ultrasonic and IC designs, $8.00. For large list of plans, send $2.00 (refundable) to SELECTRONICS, PO Sox 08121, Detroit, Ml 48208. __ CB Tricks II book. Power amplifier design and theo- ry, UHF CBtune ups. Send S19.95 MEDICINE HAN CB, PO Box 37, Clarksvtlle, AR 72830- DETECTION — Surveillance, debugging, plans, kits, assembled devices. Latest high-tech catalog $5. DETECTION SYSTEMS, 2515 E. Thomas. #16-S64F, Phoenix, AZ 65016. ELECTRO LOCK programable keypad door release system, complete kit Including electric strike; $129.95. Assembled and tested; $149.95. Free bro- chure and orders: SYSTEMS ASSOCIATES INC., 1320 Cranston Street, Cranston, fll 02920. (401) 943-2986. INVESTIGATORS, experimenters — Quality new plans. Hard to find micro and restricted devices. Free catalog. Self addressed stamped envelope to KELLEY SECURITY INC., Suite 90, 2531 Sawtelle Blvd.. Los Angeles, CA 90064. SINGERS. At last, build your own vocal filter. Re- move lead vocals from standard stereo records, CDs, tapes, FM broadcasts, so you can be the lead singer of your favorite band. Theory, manual, sche- matics S6.95, WEEDER TECHNOLOGIES, 14773 Lindsey, Mt. Orab, OH 45154. CABLE RENTERS STOP! Ifyourcurrently renting your cable equipment it's time to I o o k i nto ow n i ng yo ur own. You can save up to $1 00 plus every year. Satisfaction Guaranteed. We carry all the major brands of Converters, Remote comrols and Descramblers. JERROLD, OAK, ZENITH, EAGLE, HAMLIN, SCIENTIFIC ATLANTA, Wany more. Fast courteous service. Call today 512-250-8816 or write for your Free catalog. ™i r fe R 1 -800-228-7404 Nu-Tek Electronic 51 14 Balcortes Woods dr. Suite#307 Dcpi.298R Austin, Tx 78759 visa THE ELECTRONIC GOLDMINE INFRARF.D DETECTOR KIT U.rt uni'hvf kt.1i in. I d**ironk rir- ■™itry («■ mfiDnJ 1D ill Irp-t-t uf infriral TV, VCH, «c. rtfmoi* rocEielltrt jhJ LEdS I- r""!'--'"!' --■■--! j-i ■' rV"v j bri|bl '-■•'.■ LED. Cffcil for tatmg ibk! WTifKJEtrwi of ■nfjj.rtd uuipui - *n *lur y<>" CM *m *tt- Small- inr; II" s 1.4"', Oricrjtci nn 9V rfirtcry (hm incluJcil] Kk ioinn *ich all [vuii inJ M-Wl SS.95 E3H C3C»--- c=* OO 0& C643!) S59.9S MINI GF.1CKR COUNTER KIT III wk-NI in klii you idtfatt thr riilnsmn ihxe t>U IK LlflAI (XIMHaI ID" 1'iC i! to l* I CTI mj- iin JliIi im old wskIkV, <«npiHj Umiin Untky, rr4iomuti>r mirirr*lT. tucljnHifld rnJi- inn. Etc. Kit iltfccii ilp hj, Ihei, jMrtrnt grid nay rtJiiclan uid ttacurtti. ttntiirrc irrrii- .!:.!■■«. I.V. !\J... i, i j :. . buUcn tar} Jwr Ho AC mCup C) C«SO J &.7S JuriJ* Bint Kil (BVDC> C*W4 S 6.2S L1«trorsk Ijiltrccim KiM^VFJC) C4T43 J12.49 Micro Xrncui Tub* Ftottt Kll 5VDC) C6^(jS JI4.#S Sinmbi^d l.jwr M |9V|K"i C6394 S S.OO Ralierv T titer Kil iTtitt all Tv]KiK9VDt"l C6414 $ *.M "wbi" ci'^Tr d'l« " SU PE R BRlf " ' IT '* FD Ainvj 3/S1.00 100/325.00 UK i I lev SURFACE M0UH1 CHIP COMPONENTS it: is tir ut tsi WUI 0BIE thTOIIYALUEM MSKIffll H unoior is Wi.»« 1M/SJ » INVERTER TRANSFORMER fa, ( l»J if™, fa uu »1 J5S It king liflt n |» !S«< In :a*n DsrlKci tutn Mr. Sirdi Mhiftrit nd^M M7U$1.UhAIWI«;17» tKV TRIGGER COIL rf law i■ 0(> • l ' i Ppr , " l, " I " ,,li, '^- W "*" plm/C, Vi,BOfldmBnfY ordtri, (CD let: J. 50 in QKilpnti lo 3.04 Oiipning prVvg*. if HD OBDEHi rO: Ihr Ebilponh Coldmi.. P.O. Bdi S40S S.ollsdiile, 01. S52il PHOHf OROEB!: [t01]4il-7454 CIRCLE 135 ON FREE INFORMATION CARD LOOK IMO If you've been looking high and low for a dependable supplier of top-quality electronic parts and components. . . let MCM end your search. LOOK AT OUR QUALITY - it's tough to beat! LOOK AT OUR SELECTION — over 1 5,000 in-stock items to choose from I LOOK AT OUR VALUE — some of the most competitive prices in the industry! LOOK AT OUR SERVICE -convenient TOLL-FREE phone lines, fast order turnaround and courteous, friendly assist- ance when you need it! If these are the things you've been looking for, it's time you look to MCM ELECTRONICS. The first time you do, you'll like what you see! I- For a FREE, ONE- YEAR SUBSCRIPTION to the MCM Electronics Catalog, , Call TOLL-FREE, J 1-800-543-4330 MCM ELECTRONICS G50 CONGRESS PARK DB CENTERVILLE, DH 45459.4Q7S A PREMIER Company SOURCE NO. RE-62 c > < CO CO o CIRCLE 87 ON FREE INFORMATION CARD 95 CABLE TV CONVERTERS & EQUIPMENT • ONE 10+ UNIT UNITS SCIENTIFIC ATLANTA W/ TRI-BI . . 225.00 . . 175.00 PANASONIC WIRELESS CONVERTER 1403N 85.00 . . .74.00 JERROLD 400 COMBO W/ REMOTE (DRX3D1Q 134.00 . .100.00 JERROLD 400 OR 450 REMOTE HAND UNIT 24.00 . . .15.00 JERROLD JRX3DIC 64.00 ...65.00 JERROLD SB ADD ON 74.00 . . .55.00 JERROLD SB ADD ON WITH TRI-BI . . . 85.00 . , .75.00 OAK M-35 COMBO 79.00 . . .50.00 OAK MINICODE (N-1Z) 84.00 . . .59.00 OAK ECONOCODE (E-13) 84.00 . . .40.00 HAMUN MLD 1200 84.00 . . .55.00 SCIENTIFIC ATLANTA SA-3 ADD ON . 109.00 . . ,80.00 INTERFERENCE FILTER (CHANNEL 3 OR 6) 24.00 , . .14.00 SCIENTIFIC ATLANTA 83 CHANNEL CONVERTER 95.00 ..80.00 PIONEER CONVERTER BA 4500 SERIES 100.00 . . .85.00 TOMCOM VIP Call for price and availability ZENITH FLASHING Call for prica and availability ZENITH SSAVI Call for price and availability EAGLE PD-3 Call for price and availability VIDEO-LINK Enterprises, Inc. 165 W.PUTNAM AVE. GREENWICH, CT 06830 (203) 622-4386 MONDAY - FRIDAY 10 AM — 5:30 PM, E.S.T. IMPORTANT: Have make and model # of the equipment used in your area GTY ITEM OUTPUT CI I ANN EL NO CONNECTICUT SALES, tl is not Iris intent ot VIDEO-LINK to defraud any pay television operator and we will not assist any company or individual in doing so. PLEASE PRINT: D CASHIER'S CHECK NAME PRICE EACH SUBTOT. Shipping S3 /Unit COD: Add 5% TOTAL TOTAL PFIICE □ M.O. G C.O.D, ADDRESS CITrVSTATE/aP . PHONE SIGNATURE WAIVER. Since I, the undersigned; fully understand Ihal the ownership of a cable decoder does not give the owner ot the decoder the right to decode or view premium cable channels without proper authorization from their local cable company, hereby declare under penalty of perjury that all products purchased, at any lime, will only be used on cable TV systems with proper authorization from local officials or cable company officers in accordance with all applicable federal and state laws. Federal and various stale laws provide for substantial criminal and civil penalties for unauthorized use. Dated : Signed: ra trarrdsl P-C-13 Artwork Made Easy PD Boards Layout Software takes the Hassle out ol Creating P-C-13 Artwork. • Advanced Features * Menu Driven • Auto-Router £ Schematic Program Available Requirements: IBM PC or comjuilble '&* K F ' AW - COS 3.0 or later PC Boards S39.0D Demo siD.QfJ 2l I'J Mill Ave South Birmingham. AL 35205 |2(J5| 933-1)22 MICROPROCESSOR alarm kit. For home, auto, RV. 8 zones. Delay, valet, continuous modes. $31.95 plus $2.00 S/H. Just add power supply, case, sen- sors. PRECISION ELECTRONICS, 4N306 Norris Ave., West Chicago, IL 60185. CLOSEOUT "TV Frequency Standard" April 1988 R-F_, kit/antenna coil $55.00, finished units $200.00, PERSHING TECHNICAL, Box 1951, Fort Worth, TX 76101. CABLE T.V. CONVERTERS WHY PAY A HIGH MONTHLY FEE? All jerrold. Oak, Hamlin. Zenith, Scientific Atlanta. Magnavox and all specialized cable equipment available for shipment within 24 hours. Forfast service MC/ VISA or C.O.D. telephone orders accepted (800) 648-3030 60 Day Guarantee {Quantity Discounts) 8 A.M. to 5 P.M. C.S.T. CLOSED WEEK- ENDS. Send self-addressed Stamped enve- lope (60s: postage) for Catalog. imiDUfCST | IHyWh*JIH*TIH P.O. Boi 5000 Carpentersville, IL 00110 No Illinois Orders Accepted- SATELLITE TV 96 CIRCLE 64 ON FREE INFORMATION CARD CABLE TV secrets — the outlaw publication the cable companies tried to ban. HBO, Movie Channel, Showtime, descramblers, converters, etc. Sup- plier's list included $8.95. CABLE FACTS. Box 711- R, Pataskala. OH 43062. FREE catalog - Do-it-yourself save 40-60%. Lowesl prices worldwide, systems, upgrades, parts, all ma- jor brands factory iresh and warranted. SKYVI- SION, 2009 Collegeway, Fergus Falls, MN 56537, 1 (800) 334-6455. PAY TV AND SATELLITE DESCRAMBLING NEW. 1990 EDITION.. NEW file newest systems, parameters, tum-Dns, harassment and counlermeasures being used by and against cable, wireless and satellite operators. New original information 515.95 Pay TV Vol. 1 S14.95. Volume 2 82.95, Experiences with Vt Hi. 95. MOS.'MMBS Handbook S9.95. Build Satellite Sys- tems Under $600. $12.95. Any 3'H! or 6 $42. Scrambling Mews Monthly S24.95yr. Sample $3. Scrambling News Yea- 1 (200) pages S22.95. 'rear 2 S22.S5. Catalog SI or call. fcU'Mirlillfilil. 1 N.Y. 14216 COD'S 716-874-2088 DESCRAMBLER: Build our low cost video only, satellite TV descrambler for most satellite channels. Uses easy to gel. everyday parts. Boards & plans $35.00 US funds. Board, plans & parts $99 00 US funds. Wired & tested unit $189.00 US funds. Send check, money order or Visa to: VALLEY MICRO- WAVE ELECTRONICS, Bear River, Nova Scotia, Canada BOS 1B0 or phone (902) 467-3577. 6am to 4pm eastern time. Note: educational project only. Not to be used illegally. CABLE T V "BOXES" Converters— Descramblers Remote Controls —Accessories * Guaranteed Best Prices * * 1 Year Warranty — COD s * * Immediate Shipping * * FREE CATALOG * Call or Write TRANS-WORLD CABLE CO. 1 2062 Southwest 1 1 7th Court. Suite 1 26 Miami. Florida 331 B6 1.800-442-9333 VIDEOCIPHER II manuals. Volume 1 — hardware, Volume 2 — software. Either $32.45. Volume 3 — projects/software — $42.45. Volume 4 — repair — $97 45. Volume 5 documentation — $42.45. Cable Hacker's Bible — $32.45. CODs: (602) 782-2316. 0100-032 software - catalog-$3.00. TELECODE, Box 6426-RE, Yuma, AZ 85366-6426. VIDEOCYPHER II deserambiing manual. Sche- matics, video and audio. Explains DES, EPROM, CtoneMaster, SMusketeer, pay-per-view (HBO, Cin- emax, Showtime, adult, etc.) $13.95,52.00 postage. CABLETRONICS, Box 30502R, Bethesda, MD 20814. COMPUTER SYSTEMS FROM SB95. US-made XT, AT, 386 in modern tower enclosure. Also Commodore service, parts. TOP- TECH INTERNATIONAL, 1112 S. Delaware Ave , Philadelphia, PA 19147. When you give blood you give another birthday another laugh, another hug, another chance. + American Red Cross Please give blood CoUKll EDUCATION & INSTRUCTION $NUTS ft VOLTSl MAGIC! Four illustrated lessons plus inside infor- mation shows you how. We provide almost 50 tricks including equipment for four professional effects. You get a binder to keep the materials in, and a one- Kear membership in the International Performing tegicians with a plastic membership card that has your name gold-embossed. You get a one-year sub- scription to our quarterly newsletter "IT'S MAGIC!" Orde r now ! $29 .95 f or each cou rse + $3. 50 postage and handling, (New York residents add applicable state and local sales tax). THE MAGIC COURSE, 500-B BiCounty Boulevard, Farmingdale, NY 11735. LEARN IBM PC assembly language. 80 sample programs. Disk $5. Book S1B. ZIPFAST, Box 12238. Lexington, KY 405S1-2238. LEARN electronics the practical way. Build your own kit or do tens of experiments with your own self trainer. For free catalog: ARLI ELECTRONICS, 2155 Verdugo Blvd. #22. Montrose, CA 91020. BUSINESS OPPORTUNITIES EASY work! Excellent pay! Assemble products at home. Call for information. (504) 641-8003 Ext. 5192. MAKE $50/hr working evenings or weekends in your own electronics business. Send for free facts. INDUSTRY, Box 531, Bronx, NY 10461. YOUR own radio station! AM, FM, TV, cable. Li- censed/unlicensed. BROADCASTING, Box 130- F1, Paradise, C A 95967. INVENTIONS, ideas, technology wanted for pre- sentation to industry/exhibition at national innova- tion exposition. Call 1 (800) 288- IDE A. BYOB Begin your own business. High profits. No gimmicks. Free details. JSR ENTERPRISES, Box 249, Dept 2121 .Orange Park, FL 32067-0249. GIVE YOURSELF A BH EAK — A flfl I CE BR EAK I NUTS fi VDLTS WILL Si** YOU MONEY DN ELECTRONIC HARTS £ EQUIPMENT PTtft SHOW YOU WHERE TO FIND UNIQUE. UNUS UAL AND HAQD-TO-FINO ITEMS. j»ra| SUBSCRIBE TODAY) j£-™| 3rd CUii Mm UIA 112 DG a wik ,[■ ■< MOW In CImi M, Nl T," USA 1»« A,r Mail .-., - , .. nice ANitiml PtWutiKt Fir fin Bsjwj /W Ja% 0/fl«fiwe ff uftxtirr MAKE $75,000 to $250,000 yearly fixing IBM monitors, no investment, start from home, (a tele- phone required). Information USA, Canada $1.00, Europe, Middle East S3.00. RANDALL DISPLAY, Box 2168-R, Van Nuys, CA 91404 USA. PROJECTION TV... Make S$$'s assembling proj- ectors. Easy!... Results comparable to $2,500 proj- ectors... Plans, 8" Lens & dealers information $22.50... Professional systems available... Illis- trated catalog free. MACROCOMA, 15GEX Main Street. Washington Crossing, PA 18977... Credit- card orders 24 Hrs. (215) 736-2880. LET the government finance your small business. Grants/loans to $500,000. Free recorded message: (707)449-8600. (KS1) LEARN gold, silver, platinum scrap recycling busi- ness. Free information. Write: RECYCLING, Box 11216RT, Reno, NV 89510-1216. WANTED INVENTIONS/new products/ideas wanted; Call TLCI for free information 1 (800) 468-7200 24 hours,' day - USA/Canada. INVENTORS! Confused? Need help? Call IMPAC for Free information package. In US and Canada: 1 (800) 225-5800. r ** * * PRESENTING ***■* * CABLE TV DESCRAMBLERS ***** STARRING ***** JERROJLD, HAMLIN, OAK AND OTHER FAMOUS MANUFACTURERS » FrlYEST WARRANTY PROGRAM AVAILABLE ■ LGUTCST KOAIL/U/HO.LFSALF PRICES I.N U-5- i ORGEFft SHIPPED FROM STOCK WTTHJN 24 HOURS FOR FREE CATALOG ONLV 1-800-345-3927 FOR AU. INFORMATION 1-818-716-5914 j PACIFIC CABLE CO. INC r-r- v-t ■ \ it*, BIVD. OEPT RE1 89 DESCRAMBLER MODULE LATEST technology alternative to Jerrold SB-3 or Radio-Electronics Feb. 1984 project. Featuring electronic tuning, AGC, auto- on .'off, AC/DC power, mini-size. AST, and more. For literature — SOUTH- TECH DISTRIBUTING, (813) 527-2190. INVENTORS INVENTORS! Can you patent and profit from your idea? Call AMERICAN INVENTORS CORPORA- TION for free information. Over a decade of service 1 (800) 338-5656. In Massachusetts or Canada call (413) 568-3753. . MASTERCARD AND VISA are now accepted ^ for payment of your advertising. Simply > complete the form on the first page of the ^ Market Center and we will bill. (O to o 97 CONSOLIDATED ELECTRONICS t ^lMUM^ -'jSVLS FIG. 2 A much easier way to do the job is shown in Fig. 2. I've ganged the four and gates in a single package in parallel to provide a bit of extra drive for the output transistor (or relay). You should use CMOS parts, as they're perfectly happy working from twelve volts. Using a TTL part means having to add a 5- volt regulator to the circuit and that's a good way to make things more complicated. R-E YOU CAN ONLY FIND A WIDE RANGE SELECTION OF ELECTRONIC KITS AT MARK V ELECTRONICS, INC. A indicates the level of difficulty in the assembling of our Products. A Beginner A A Intermediate AAA Advanced + Fully Assembled FC-1000A TY ~ 45 SM-328 ■ A ^j*, ? (pi ■"*' » u -'« " ' TA-5600 M TA ' 802 __ AMPLIFIERS MODEL DESCRIPTION KIT ASSEMBLED TA-001 1W Mini-Amplilier A . . , S 5.07 TA-006 6W Mini-Amp lilier A 6.90 TA-007 12W MrnrAmpliher A 11,20 TA-10 Stereo Pre-Amp. w/magnetic mic. amp. A , , 8.20 TA-28MK2 Digital Voice Becorder A A 30.00 S 40.00 TA-50A/B Multi-Purpose Melody Generator A 11.84 16.58 TA-50C Multr- Purpose Melody Generator A 1 2 65 1 7.71 TA-120MK2 Class'A'MainPowerMonoArop.AA 31.25 TA-300 30W Multr Purpose Single Channel Amp. A 20.00 TA-302 60* SIMM Power Boosts A A* 50.00 70.00 TA-3221 SOW 4- SOW IC Stereo Amp. wMtovtl display A 36.50 TA-32JA HO SOW + 30W Stereo Amp. A 29.50 TA377A FET Sleteo Pre-Amp. AAA 59.95 7500 TA400 40W Solid Stale Mono Amp. A 28.00 TA-A77 120W Moslel Power Mono Amp. A A 68.00 TA-800 BOW + 80W DC Pre-MainS Power Amp AA 60.92 TA-802 80W -I- 80W DO Slereo Main Power Amp. AA 45.94 TA-820A 60W -t- 60W OCL DC Pre- Mam Stereo Amp. A A 49.00 TA-10DOA I0OW Class "A" Main Power Mono Amp. A A 59.69 80.59 TA-1500 IOOWi2Cla5s"A - DC Slereo Pre-Main Amp. AAA 73.70 TA-2400A Electronic Ectroa Revelation Amp. AAA* 93.30 118.30 TA-2500 HQ Pre-Amp. w/10 band graphic equalizer * 90.00 TA-2800 Hi-Fi B>Fet Pre-Amp. W3 way long control A A 48.90 TA-3000 Stereo Simulator AA 33.20 43.3S TA-3600 300W HO Hi-Fi Power Mono Amp AAA 86.00 110.00 -477 MODEL TY-1A TY-7 TY-B TY-11A TY-12A TY-13 TY-14 TY-1S TY-20 TY-2JB TY-25 TV-S5 TY-36 TY-3B TM1MK111 TY-41 MKV TY-a.2 TY-43 TY-45 TYA7 SM-222 SM-328 SM-3S3 5M-666 T-1 T-2 #8501 #8501 SM-333 ,H= ^^™ SM-666 MISCELLANEOUS DESCRIPTION KIT ASSEMBLED Saltery Flourescent tight Driver A . . , , $ 5.1 9 Eleclronic Touch Switch A 7.1 5 ELeclronic Lotto A 15.00 Mulli-Funcllonal Control Switch A , . 5.1 9 Digital Ckick wrtimer A 16.63 Dolor Led Audio Level Meier A 20.15 Electronic Shock a 6 25 High Frecision Sound Control Switch A 9.22 V Shape Color Led Level Meter A A , 21.45 3 Channel Color Light Controter A A A * 7150 SB2.50 Stereo Loudspeaker Protector A 12.65 FM Wireless Microphone A , 9.22 AC/DC Ouam Digital Clock A 18.00 Sound/Touch Control Switch A 12.00 I ritrared Remote Control On it AAA 15.00 2S.00 Inlrared Remole Control Unit AAA 20.00 35.00 Bar/Dot Level Meter A A 24.15 3'A Digital Panel Meter A 33.00 46.20 20 Steps Bar/Dot Audio Level Display A A 38.45 Superior Electronic Roulette A A 19.46 ? Bands Graphic Equalizer AAA* 26.80 36.90 4 Channel Professional Color Light Controller * 1 50.00 Audio/Video Surround Sound Processor AAA* 62.00 63.00 Dynamic Norse Reduction A 26.00 34.00 LCD Thermometer Cluck w/in-outdoor sensor * 22.00 LCD Thermometer Clock wl f £ C measurement * 19.60 Panot Talking Crock * , 1 2.20 Mynah Talking Clock * 12,20 -WE ACCEPT MAJOR CREDIT CARDS. MONEY ORDERS AND CHECKS - BUSINESS & SHOWROOM HOURS : (PACIFIC TIMEI MON.- FRI.: 9:30 AM,- 5:00 P.M. SAT.: 10:00 AM.- 5:00 P.M. TERMS: S1Q.0OMIN ORDER* S20MIN.CHARGECARDOROER • WESHIPUPSGROUND* ADO 10% OF TOTAL ORDER(MIN.$3.00> FOR SHIPPING OUTSIDE USA.ADD20%(MIN.S5.00)» TRANSIT INSURANCE ADO 5% Of TOTAL IOUTSIDE USA ONLY). CA RESIDENTS ADD SALES TAX " ALL MERCHANDISE SUBJECT TO PRIOR SALE ■ PRICES ARE SUBJECT TO CHANGE WITHOUT NOTICE • WE ARE NOT RESPONSIBLE FOR TYPOGRAPHICAL ERRORS CATALOG OR INFORMATION: 213-888-8988, • PHONE ORDER : 1-800-423-3483 (IN CALIF.) 1 -800-521 -MARK FAX : 213-888-6868 MARK V ELECTRONIC , INC. — 8019 E. Slauson Ave., Montebello, CA 90640 CIRCLE 93 ON FREE INFORMATION CARD C > 31 ■< CO CD O 99 ASSEMBLE YOUR OWN COMPUTER FOR LE$$ IBM XT 10 MHz Compatible Kit $379 • 4.77/1 □ MHz Motherboard • 256KB RAM (640KB max) • 1 SOW Power Supply • Floppy Disk Controller • One 5 V 4 ' 380KB Drive • MonoGraphlcs Card w/ P • 101 Key Keyboard • Case (3LED,2Button,Key) • 12' Amber Mono Monitor • Installation Guide & Manual IBM AT 12 MHz Compatible Kit $705 • 8/ 12 MHl Molherboard • 512 KB RAM (4 MS max] • 200W Power Supply • Floppy Disk Controller • One 5 *.'.,■ 1.2 MB Drive • MonoGraphics Card w/ P • 101 Key Keyboard • Case [3LED.2 Button , Key) • 1 2' Amber Mono Monitor • Installation Guide & Manual * - Display Upgrade: Hard Drive Option: CG A Package $200 20MB w/CTRL CT-S275 AT-S31 5 EG A Packag t S455 30MB W/CTRL XT-S31 AT-$4 1 VGA Package $500 40MB w/CTRL XT-S390 AT-S4 1 5 MS-DOS with GWBASIC S75 Li sl rjo (S3.00 minr/rturr, charg.) 'Koun: &3Q un- 6:00 prr. EST, Monday - Friday 'Mail order customers, please call for shipping estimate on orders exceeding 12" SUB WOOFER Dual voice coil sub woofer. 30 dz. magnet, 2" voice coils. 100 waits RMS, 145 watts max, fs ■ 25 V,z $ ohm (4 and 9 ohm compatible). SPL = 89dB lWrlM. Response: 35-700 Hz, QTS = .31. VAS=10.3cu. ft.. Pioneer #A30GU3O -55D. Net weight; 6 Its, #290-145 f$f° 15" THRUSTER WOOFER Thrusler by Eminence. Made in USA. Poly foam surround, 56 oz. magnet. 2- 1/2", 2 layer voice coil. ISO watts RMS, 210 watts max. 4 ohm. [S-23.E H2. QTS = .33, VAS=17.9 cuft.SPL=94,edB 1W/ 1M. Net weight: 15 lbs. $43.50 § 290- 180 (1-3) $39.80 (4-up) GRILL FRAME KIT With this kit you can malee speaker gr.l. frames up to 30" i 40". Kit includes 4 comer pieces, 3 T brackets, and T frame bais. GrlU mounting kit included. #200-333 $8.50 (1-9) $7.80 (10-up) 18" EMINENCE WOOFER MATE IN USA 100 oz. magnet, 3" voice colt. 250 watts RMS, 350 warts max. s ohm, 30 Hz resonant frequency. 22- 2700 Hz response. Efficiency: 95 dl IVW1M. Paper cone, treated accorclian surround. Net weight: 29 lbs. #290-200 $98.90 (1-3) $89.50 (4-up) TITANIUM COMPOSITE TWEETER TituiLtm "s dop-astod on » FCryitur derr* to combine lt* ufnagpi of beth hud nnd watt dome EedmtfogiaE. B ohm Ferro fluid cootod voice coil ti=]200Hi r SPL = 90dB 1W/1M, KwiitPJtffi. 70 walls mix. i' round. Pejydix p»it *DTW100T1£5. $27.50 #270-047 (1-9) G $24.80 (10-up) CIRCLE 56 ON FREE INFORMATION CARD Mill Oftfw ElKhorilo* WoridwWt ameco ELECTRONICS Mail-Order 24 Hour ■cs — Order Hotline SIP & SIMM MODULES EULH& Function Prlc* siiwr iomps.? ioon> j»k < »s>ww ii uci>i 11995 auEGrar i8mpsv2 ioonsiMEo.9SiMUBsdi) "«ss5 11256*9*10 262141x9 100ns2S6K>9SI«!t*isL*jllsl .4995 H756A9B90 262.144.5 10ns 256K 1 9 5MM .64,95 12'30C*18-10 1.048.576x6 ILTOnslMEGiHSIMM 1 &i 95 «'O50*MM 1.049.576.9 10ns TMEG x 9 SIP (His Lejosi 189.95 121000A9&80 1049 576x5 1*5 :HEGi9SMU 169 95 Ur^-ade lor Madeis :3Q. 5-2 a-.s 60 7400 Pant _Li-_U>i 7400 7402.- 7404..., 7405 7406. 7407 . 7408. 7410... 7411 . 7414.. 7418 . 7417... 7420 7427 7430 7432 7438 744? 7445 7446 7447... 7473 20 19 29 19 29 19 35 25 39 .29 39 29 35 .25 .29 .19 35 26 49 .39 35 25 35 25 29 .19 29 19 29 .19 39 29 39 .29 49 39 -rs- 89 .79 .89 .79 39 .29 PutKo. 1-3 10, 7474 7475 7476., . 7483 7495 7486 7499 7490 7493.. 7495 74107. . 74121.. 74123... 74125... 74147.. 74150... 74151... 74154.. 74161 74174... 74175... 74193. . 39 29 49 .39 45 ,35 59 .49 65 .55 45 35 225 2.15 49 MS 45 .35 59 .49 29 19 39 29 .49 -39 ..... A3 .39 199 1.69 ... 135 1 25 .39 29 ■ 35 i ?r, 1:9 59 59 49 59 .49 79 J69 MICROPROCESSOR COMPONENTS 74LS 74LS00. . 74LS02 74LS00 74LS04 74LS0S 74LS06 ... 74LS07 74LS08 741S09 74LS10 74LS11 74LS14 74LS20. 74LS21 74I.S2? . 74LS30 74LS32 74LS38 .. 74LS42. . 74LS47 74LS73 74LS74 . . .. 74LS75 74LS76 . 741S83 71LS8S 741S96 741 S90 74I.S93. 74LS123 . 74LS125. . 74LS132.. 74LS138 . ?8 u 28 28 26 29 49 39 28 IS ?9 SS 26 26 36 49 65 39 35 25 39 .29 39 29 55 ,45 29 49 39 49 .39 49 .39 49 .39 74LS139. 74LS151.. 74LS153 74LS154. 74LS157. 74LS161... 74LS163.- 74LS164- 74LS165... 7i-S , l!6 74LS173... 74LS174. 74LS17S. 74LS191 74LS192... 74LS193 74LS194... 74LS221. 74LS240... 74LS241... 74LS244. . 74LS245.. 7 J'.. S 25 7 74LS259. . 74CS273 74LS279... 74LS367... 74LS373 74LS374... 74LS393... 74LS541 ... 74LS590. . 7JLS688 49 39 49 39 49 39 129 1 19 45 35 49 39 49 39 59 49 75 65 89 .79 45 35 .39 .29 39 29 ,59 49 69 59 69 59 69 59 89 59 59 .49 59 .49 59 .49 .79 .69 .49 39 .99 69 B9 79 49 39 49 39 .79 69 79 .69 .89 .79 1 29 1 .19 5.95 5 95 2 39 2 29 74S/PROMS' 74S0O 74S04 74S32. 74S74 .. . 74S112.. 74S124 74S138 . 74S153 74S163 ... 74S174... 74S175 .25 25 25 25 .25 1.25 .49 29 75 29 .39 74S188' . 74S189 .... 74S24D. .. 74S244 74S287- ... 74S286' 74S373 74S374. . . 71S3B7' 74S472V. . 7455? 1' 1.49 1.49 1.29 2.95 2.49 CD-CMOS CD4001 CD4M2. CD4007 CD4011.. CD4012 CD4D13 CD4015. CD4016 CD4017 CD4016 ED40W CD4W1 CD4024 CO1027 . C04G2S CD4029 CD4030. CD4040 C 04042 CD4043 CD4046 CD4047 CD4049 CD 4050 CQ4051 . ;Oi052 CDJ0S3. CD4 060.. CD4066.. C 04 069. C 04070. C 0407 1 C 04072 ^rjj;:j CD40B1 CD4093.. CD4094 CD4503.. CD4511 ... CD4516 CD4520. CD4S22 CD4528 CD4538 C04543 CD4594 CD4585 .59 59 .59 .65 .29 .25 -29 .19 19 .19 19 35 .99 39 .59 75 69 .75 69 .79 .79 .49 .69 NECV20& V30 CHIPS Replace the 8086 or 8088 In Your IBM PC and PilLMa Increase lis Speed by up 1c 30". Price UPD70106-5 (5MHI1 V20 Cnlp 5.25 UPD7010B-8 SMHzj V20 Chip 6.95 ll PD701 08-10 10MH*) V20 Cilia 10.95 U PD701 1 6-8 8MHl) V30 Chip 7.95 UPD70I 16-10 flOMHi) V30 Chip 13.49 Z8C.Z8CAZ80B, SERIES Stum. East Z80 17^ zsoa Z90A-CTC ZB0AOABT ZSOA-PiO 1 29 165 495 189 zsoasoo Z80B ZBOfi-CTC zeoe-pio Z6400HB1 CPUftMHi SO0O SERIES 6031 _ 395 2.75 2 55 3 95 395 395 69C31 . 6035 B039 6052AHBASIC 6030A . 6.95 .1.25 1.59 2495 1 95 6065A 8085A-2 8086 359 3 95 6097 (5MHz) 89 95 80871 (10^HI) 169.95 8087-2 (6MHz) . 12995 0088I5MHJ) 4 95 8089 2 IBMH.-i . 695 8155 ' 2 49 6000 SERIES Conflnutxt 8155-2 8! CM 375 4 25 S2C11.. „ ., 655 8216. ..._ 1 39 8224 1.49 8237,5 _ 8243 6250A 425 1.95 4 95 625CB iFo- IBM> B251A 9253 6263-5 82C53 5 6254 8256A-S 82C55A-5 8256. 5.96 155 1.89 1.95 395 4.95 295 4.49 1195 8259-5 2.25 8272 3.49 8274 4.75 8279-5 2.95 8282 2.95 S284A 1,95 STATIC RAMS Pin Nc. Kl6--i 2102 2112 21 UN 2114H.2I 21C' 5101 6116P-1 6iia>-3 6116IP-1 6I16IP-3 S264M0 6264P-15 6264LP-10 6264LP12 E254LP-15 6514 -iiM ■:. 43256-1 5L 62256LP-10 6225SLP,12 62256LP-15 FunMInn 2046ii IIK4il 255*4 1024x4 !024>4 1024x4 256(4 2MM 2048x1 2041x1 2041x1 1192x9 119219 11 92x6 1192x9 119219 1024x4 32.76SJS ;; :t=ii 32.761x8 32.76911 32.765x1 ■f>5 350« 450rsl*as tSOtis. 2Kns Low Power Prlca X5015ICMO5). lOOariWOMOS ISOrariiKlCMOS.. 100rsire*)LPCMOS 15013 (•■&) LP CMOS .... lOOrs ISM) CMOS _. . 1 50m (64KJ CMOS. , ! 00ns (64 K I LP CMOS . ■cCr.i 'A» _ s :V0S l50rai64K|lJ>CMOS.. . 350csCMOS HOC! (256SJ to*. Powel .. •50ns i256f| Low Power •K»I|256K1LPC«0S._ 12!>!!|256K|LPCMCS.. •50ns I2S6K! LP CMOS 295 .99 ...249 99 1.49 49 . 196 J 19 279 309 __675 .629 6 95 . .6.75 6,19 325 10.95 .,995 -11.96 ..11.25 1095 DYNAMIC RAMS TM544-.6-12 TMS4416-15 41 16-1 S 4129-15 4164-100 4164-120 4164-150 412564W 41256.10 41256-1 OS 41256-120 j'Lit ■;; 4126412 11464-60 1 1461-52 41461-15 51256-10 5HO00PM 514256P-10 511251,10 19.394-4 16.394x4 16.364x1 131,072x1 65.536x1 65.536x1 6S536I1 262. 1«4x1 262.14411 262.144x1 262.141x1 262,1441 1 64Kx4 65.536x4 65.53rM 65.536x4 262,144x1 1.016.576x1 1.W1.57&' 262.144x4 292114x4 12oni 5H 5 49 1 50ns (Piggyback! — - l.QS 4« J,75 &5ns 6 95 l2«ru . 3.$9 3.25 _ tM 80ns \\ Mag), ■nnrwMUiurt 1 Qflns ( 1 M*g,. ■ OOns State Coium n ..._ 13 B i?95 14.49 26.95 EPROMS IMS2516 IMS2532 TMS2532A 1MS2564 TMS2716 1702* 27C6 2716 27161 27C16 2732 2732A-20 27C32 276425 2764*20 2764*25 27064-15 27129-20 27129-25 27-28.' ■: 27-2M-20 27C12S2J 27256- 15 2725620 2725625 270256 IS 2JC25925 275-2-25 2JC512 15 27C512-25 27CO10-I5 66764 69766-35 2048x6 *096>9 4C«i! 6192x8 2646x8 256x1 1021x1 2041x1 2041.1 2048x1 4096x1 4098x9 4096x9 8132x6 81 92>9 9192x9 6192x6 16,39111 16.364x1 15.361x1 19.394x1 16.394x8 32.766x6 32.766x9 22 768x6 32.768x9 32.765x9 55536x6 95.5364! 65.5361! 450ns |25V| 450ns |25V| 450n>l125V| 150ns |25 u ) 4SaiBl-Sl/..SiUt2V| ._ 2Kllixs, 459ns 163ns |2$V) 35*«I25V| . 150ns 1 25V) CMOS 15(Hm25Vj 200«(21VJ 450ns (25VJ CMOS 250ns (21V| 200ns 112 5Vi JSOnxHliSWl iSTJris in SVI- CMOS 290ns 121 VI. 250ns 121 «| 150ns H25Y1 209x11 112 5Vi 250ns 121V) CMOS lSOftS [125V] 20CH(125V). 250ns (12 j¥], !50m(12 5l/|CMOS. 250ns (12 5V| CMOS 250ns(12 5V| •50nH12S¥lCI4OS 250ns (12 5VI CMOS 131.072x6 ',50ns II2 5»; CMOS 11 Mtgi 9192.1 64K450"s;25Vi ICnoEniftj- 91924) 64K 350-4 r25Vi lOulpul EraWJ 4 95 5.95 525 695 6.19 125 (.95 349 335 425 9.95 3 95 425 3.95 119 319 195 5 95 525 = 55 475 595 149 549 435 725 519 725 995 719 .1995 1195 1595 EEPROMS 2616A,252Cl8x8250r>si9V5V)5V HoidWrlle .5 49 2817A 2018x8 350ns 5V ReufWrlte.. 6.95 2864* B 1 S2i8 !S0ni 5V Rlld Write 1 nn ' r. o n.Bil095 2865* 6192x8 250ns 5V FtHd Write. 10 95 SODO SERIES Conlinuod Pan Mo. FM2£ 8286. __ tSS 8741 9*9 8742 ..14.95 9748125V) 7.95 8748H (HMOS)(21V) ... 9.95 8749 9.95 8751H(3 5-12MHl| ..34.95 8755 1395 80266-1 Dl10MHx)LCC 29.95 B02S7-3 (SMMxl 109.95 60287-8 ISMHJ) 209.95 90287-10 flOMHxl,. .239.95 80386-16 PGA 259 95 B02«7-16 (16MHz).... 349.95 80387-20 20MHI, ...399.95 M387-25 (25MKH 499.95 82284 ItxMHll 5.49 62288 (6MHz| 6.95 DATA ACQUISITION ADC0604LCN 3.25 AocoeasccN 5.49 A0C0S09CCN 3,75 ADC1205CCJ-1 19.95 DACO803LCN 1.49 AV-3-1015D 4.95 AV-5-1013A 2.95 6500/6800 68000 Series Part No. Prixse 6402 3.75 6502 2.19 6502A 2.59 65C02BMOSI .. 695 6520 _ 1.59 6522 _„ 2.95 65C22 „ ...4 25 6551 . 2.69 65C802JCMOS) . -IS 95 6800 .... 1 .75 6802 _ 295 6608 .. 2.49 6810 1.25 6821 ... .._. 1.75 66R21 2.25 6840 3A3 6852. 7S wceaooota 9.95 WC6KXML10. .... ....11.95 MC6»0OSPa 8.49 HC68010L10 19.95 MC68O20HC123. . ..59.95 MC68450LIO ...... . 29.95 MC6S701 19 95 HC66705P2S ,1595 MC6S705U3S 17.95 MC68681FC16A ...129.95 MC6888 IRC 20* 159 95 Commodore WD1770 8.95 S13052P .99 6504A 1.19 6510 11.95 6526A 14 95 6560 6.95 6572 6.95 6682 (9V) 795 8502 ,. 7.95 8564 „ 2.95 8566 .. - . 6.95 6701 , .995 8722 ... 8.93 '82S100PLA" . . ...15.95 325572-01 ...17.95 901225-01 1595 901226J)t ...15.95 901227413 15.95 901229-05 901460 03 901486-06 15.95 1.95 .... 295 MISC. COMPONENTS 'taspocsa "Nett 825' iXPLA = U1 7 lC*-} 74C/CMOS 74CO0 « 74C02. 75 74CW 71009 74C10 25 74C14. - 74C32 .49 •5 74C71 74C85 ■ 74C86 J1C89 7UDD. 74C151 71C1S4 74C1S7 74C160. 74C161 74C162 74C173. 74C171 J4C175 74C192 J4C194 71C221 74C240 71C2H 74C373_ 74C374 74C31I 740912.^ 74C915. 74C917 I4C920 74C921 74C922 71C923 71C825 74C926 TANTALUM CAPACITORS TMl 1|ilra35V. 19 I TM4.7 47,110 3Sv 45 TM1 lul #35V .19 TM6.6 68u1®3SV 59 TM2 2 2.2n!@35V 25 I TM10 11V fg 35V.. 69 POTENTIOMETERS Values available (insen ohms Inio space marked "TOn 5O0Q, IK. 2K 5K. 10H. 20K, 50K. 1 00K. 200K. 1 MEG J3PXX31W»11.157urt. .99 I S3PXX 1 ;-■■:.■.'.■ ~ . .-,..■■ Sapp , . . $249.9 5 SCAN200 Log,'** 20TOP1 Scanner $1 59.95 SMGC Mancororne urapntcs Care $34.95 U PS 1 SO 1 SDWuriiwsTijpuoli! PmtM Supply .. $1 49.95 20 1 2WR Mra VMcaJ casa w.*00W Sjppy ■• ■■ $1 29.95 iOOE External S5O0 Baud ... . $749.95 DOS INemsl ino Eeud $49.95 00B Iniernal 2400 Baud £99.95 IBM Compatible j^w Cases and Power Supplies O JE101Q JE1011 jEima JEiCrW JE1032 JE2011 JE2012 JE2014 JE2019 ll Fgp-TopSnrxiard POXTCase 539.96 Side StanfcidP&xr Case $39.95 aUeBabiATCasa $59,95 fSOwa PC.XT Purer Sucpy $59.95 Z03i>a« Baty *r PmerStipV $89.95 veaia Lia»50CW P*r.Supplf $279.95 _ lli.Vtr 04 Kay Enhanced with Trackball (140 DPI Resolution) ......$99.95 PROTOTYPING PRODUCTS U lameco Solderless Breadboards C Dim. Contact Binding £21 E23 E24 E25 E26 E27 L- » W" Points Posts Price 3.25x2.125 6 5x2125 6.5x3.125 6.5x4.25 6.875x5.75 7.25 * 7.5 400 930 1,360 1,560 2,390 3.220 $4.95 $6.95 $12.95 517.95 $22.95 $32.95 3.5" and 5.25" Floppy Disk Drives MPFIt Pictured Sony M PF1 1 3 5' 720KD Internal Drive ... . $69.95 SMK 5.25" Installation Kil w.'Faceptate ., $14.95 Toshiba 3S6KU 3 5' 1 44Mb Iniernal Orms $109.95 I Soldering and Desoldering Stations 60 Wall Digital Display Soldering Slation • Electronic temperature control Irom 200° to 878°F * Temperature displayed on easy to read .560"H 3-digil LED readout ■ Ntehrome heating elamant XY960.... $99.95 60 Watt Analog Display Soldering Station ■ Electronic temperature conlrol Irom 200° to 878°F • Cartridge heating element tor a longer life of the soldering lip XY1683 -..$59.95 60 Watt Analog Display Soldering Station ■ Electronic temperature control from 200° to 878° F * Ceramic heating element for a steady temperalure and long life XY266Q $89.95 30 Watt Electronic Temperature Controlled Desoldering Staiion » Electronic temperature conlrol from 212° to 842°F • Sell-contained high rotary vacuum pump XY999 $279.95 I TEAC FD55B 5.25- asoKb Halt hi. $99.95 I FD55G 5.25- 1 1Mb Han Hi SH 9.9 5 | Jameco JE1020 5 25' 360KI) Hair Hi Black $ 89. 95 I JE1 021 5 25" 360KD Hall HI. Gray $89.95 J E1 022 5.25- 1 2Mb Ha.t HI Gray $99.95 Hard & Hard/Floppy Disk Controller Cards Ml M Hintt-lofp)' RLL llint/rlappy CuriifjulL-,- TyfjL- MM|P&Hl)@3:1lnBntin SD236 (ATI 336 @ 2:1 Interlaave 30236 (ATM3S § t:l Interleave 1 Part No. i Price Part No. •' Price ' Part No. ' Price Pari No. I Price IW4A37M19.95 iddjvmmi s-:9.as t009VUk11 5-^:^ 1(K)3VSS1.,S143.S5 ::":6VSHi3 L E3 95 -■''.'.'I,' 25H)S5 10)3VSfl2'S1t9g5 lffi«V£R£S1E3 5a 355 Shoreway Road elmont.CA 94002 4 Hour Order Hotline (415) 5S2-8097 AX'S (415) 592-2503 or (415) 595-2664 elex 1 76043 - Ans. Back; Jameco Blml ata Sheets - 50c each end 52.0Q Postage tor a FT7£7£ 60-Page Catalog 1990 Jameco Electronics 1/90 1M is a registered trademark ol ilernationat Business Machines VISA' 24-Hour Order Hotline (415) 592-3097 • Customer Service $25-00 Minimum Order ■ U.S. Funds Only I CA Residents Add 6%, 6.5% or 7% Sales Tax I Shipping . Add 5% plus St. 50 Insurance I (May vary according to weight and shipping melhod) | Terms. Prices subject to change without notice. | We are not responsible for typographical errors. We reserve the righl to substitute manulaclurers. Items subject to availability and prior sale. Products pictured may only be 'epresenial ve Complete Lis! ol terrnsrwarranties is available upon request The Following Services Are Also Available Through (415) 592-8097 From 7AM- 5PM P.S.T.: Technical Assistance ■ Credit Department ■ All Other Inquiries J Mm Older Electronics 'Woridnniee ameco ELECTRONICS ■:r:.^ .'■:.' ~ CIRCLE 114 ON FREE INFORMATION CARD 1 -800-344-4539, 21 e eat-33B0 9103608882 Dim KEY COUP DISC CAPACITORS wis lKffl- m 225 Nuo 11500. 1* 2 75 1800 "W P+413 " hug 2700 >K 2SJ 33TO IK P442J ,'-• ?*\x 4JCKJ IK 5» &CO IK KKO'LK 3*4 F4*?7 P-4428 4J3M-H " M1« 94 NTtl 4T0W » 1 01 M43? I"'- MM lOM'lfO M P44JJ 2200 '53 ; WjZ 1500 1W » P4434 :■:-;.-. too P443& nam am ico 79 P4436 HCO/5C] M.l MM 4700 'loo 1 CO |j;. r , mm ,71 P443S ISOM.'S* "■ P<300 0VI ft » P443t 22000 M 109 N3t9 H P+440 racB r.n ..i >:. H W441 470M.'M 1 73 ea P4409 M«J '1 PHtq IS' 500 7S 1*4*10 Wa» P+403 BffiM 79 P4411 SS'WO H" 79 M*12 100 KG 1.91 PHQS 37'590 7fl P4413 IM'SO* ':: 3B P-'-ii I '"- 1M-&QC 2 03 9fl C**i5 1M'50O 270 PMtft 4?.fi09 1 13 p«lf, ;.-.- r,-„- - :.! CVffVDH. PrlH FWfl r?>'0 33>» .;-.- PMll * 7 '6 3 31 POTJ 4 7.25 '-i P»12 (1 S'6.3 34 MM S&/S l:>: pjhm ia.-aa i '■■- PMU hE-E 3 50 15/25 : "1 P?G16 22/93 « PJOS1 2J/*5 p-joi; *Mft3 J& Pitt! p»ia MU MB PK&4 9.1 H-" 35 V.' P3D19 tt0r&3 l.«3 P5DH, 9 22.' 35 'it P30M wru i.» P2056 D-33-3U- ra»* 220' 5 3 7.B5 "tf*? 047/35 ;/.' «L« PSC6B *M>35 ,■„ p;o:: 2 7. 10 » P2059 IjD/S r pitiM 3.3/10 .31 P2060 I.SJ3& H ('■;■.>::* ft.T/10 .34 ■=■-' TOOJ? a.3/3s P20M 10.10 .59 P2MJ 4.7/35 i'i l-i'j?-- 15' 10 SO >: *2W6 I0'3fl 1 33:10 .« MOM 15.95 1 i:«! r^v* HW1B MB 4 1 P2^» oa-3i i-tc:-:; 103,' Id Klljl 22/36 2.S0 FJBB 150/10 e.99 UJ wiea jjias. 1.3 JB rasa 1.5' If .23 0,1 /W .':-: C20W 0.15/ 50 ■■; i-."-..-, 3.3'1fi 33 n?.>"l 2J.W -■: '■o;t- 4.7' IE 42! wotis O.M'SO •-:: P297> 0.47/BO '■A F2PH W1I .60 0.61/50 I' 1 Piosa 15 'IB .74 F2073 l.p'M -..: P2074 1.5/50 ,:: 33/11 LIB P20J5 2.2/50 ■i P20U &rw 1.B2 3.3/M 1 i-: MOT 4.7/50 1 -1 raw [59/ 1* flS/M 2 ■ i :■;■;»; SERVICE CHARGES VOLUME DISCOUNT 4 000* 3.99 Add3?.0Q I Q.QQ t «.91 NET * 1'O.OMJS DO Add W.75 4 100.00 *?4S 99 Lni 10 . J i'b.JM'M.u 93 Add 10.50 ft25DDQ.U99.99. . . , L«J 15*/, ft MOD JM. 99 Add ffl.25 * 500 00 *999 99 lc** 20 ' , • lOOOAUp NoCtwtifl 1TO00«Up Le»25% 104 CIRCLE 82 ON FREE INFORMATION CARD EQUALITY PARTS A DISCOUNT PRICES &FAST SHIPPING Oil CLECTROniCS CORP. 3 to 6 Vdc MOTOR With GEARBOX Probably designed for chi Ids toy. Lever selects 2 forward and one reverse speed. 1 st gear aprox. 120 rpm/evdc, 2nd gear aprox. 300 rprrV6vdc, Reverse aprox. 120rprrV6vdc. 3.35" X 1.75' X 3.25" CAT# DCM-10 $6.00 4 AA BATTERY PACK (USED) Four AA nickel cadmium batteries connected in series to make a 4,s volt pack. Batteries are in a 2X2 configuration with a 2 pin connector attached. The lour batteries can be separated into single AA size solder tab nickel cadmium batteries or resoldeted into other configurations. SPECIAL SALE PRICE ■ WE R E ( 4.00 por-pooh- NOW $3.00 per pack CAT* NCB-41AAU 6 VOLT D.C. 9.5 AMP/HOUR GEL-CELL Elpower# 695 6 votl, 9.5 amp/hour rechargeable gel-cell battery. 4.25- X 2.75* X 5.5". Quick connect terminals CAT* GC-695 $15.00 each rC> 12 VOLT DC MINI FAN Howard Li^du stnesjf 3-15-010. Operaiaion 12 Vdc, 0.10 amp, 1.0 wan Com.p»ci plasae houing. 35- iquart X t-275" ttwfc. 9 Utnie fan. Two 9* pigtail lead*. CAT* CF-121 5900 each 115 VAC COOLING FAN STANDARD SIZE COOLING FAN, Feature! d'ia east nwi.il houtmrj for sr/efujtti and djrabiliiy. tMPE DANCE PROTECTED 4ii/ifi"squaraXi i/T^uep, Faciory now .20 Vac Tars. CF1-N $9.50 each WALL TRANS- FORMERS ALL PLUG DIRECTLY INTO 120 VAC OUTLET s vdc 9 2» mm cati dctx-c» 52.25 9 Vdc & 2H> m*. CAT* DCTX-K5 12.50 IdVkSI KTfp. CAT* ACTX-lUS |3.60 SWITCHES ITT PUSH BUTTON ^^^ irrMDPLwfwt. a-4-5t: f§§=3 1/2"" gray rectangular ^*tt* ,1 "T l-a^ cjap. S.P.S T. N,Q. Puthtocto«*.FUTEO:0.1 amp irwr-fchinp. , 2$ amp c*ny curreM. P,C. mount, CATi PIN* Soceedi * irj-fofiftQQ * 10010**50.00 10 POSITION MINI-ROTARY G.ayhilp S6P3t5-0l-l-lON-C Mini rottvy iMfch. No^tetlng. 1 deck, lOpoatonn-. .125'om. Bftaft X .JTJ.-icjng. J7T behind the panel depth. P.C. pn. cat* yns.in WAS *2.so ™ $ : .50 4 SPOT PUSHBUTTON Muqwdti lft*3 Haled 6 Amp* 1 .2*250 Vac. Black plastic poahbtjtloriL Switch tod-/: or X >** X ,65*, CATi P3-1» tl.tfeach • 10 lof 11. 60* PUSHBUTTON SWITCH s.p.s,t.. ixxmiuiy open mom»TMry pg*rv tAJCifjn iwii.ch. Red pi eitlc equator .ir dia. Chrome bezel 6fl- dtolMMf . Thr«(J*<| bushing mounta In ,60" d i-vn Cftutlt hak . Rated 3 amp ^ 2&0 Vac. Sold*r Irjcp Jef rrtnai*. CAT! PB-20 $1.00 nach LED'S STANBAHO J UMBO ^ DIFFUSED TLartaiia RED CATt LED-1 lOlcSl.Se ' 100 Tor SI 3.00 OHEEM CS T> LED-! lOtefSS-OO- 100 for 117.00 rELLOur CATS LED) ictfer 12.00 ■ too tor 317.00 FLASHING LEO ,.l with buil in Hashing circuit ^J Dparataa on 5 nolla.. . BED HMu* M CATJ LELH 10lofS9.50 I GREEN tl-00 aash | CATi LED-4G 10 lor If. SO .... BI-POLAR LED M Lighta REO ona d*acrkjo, TIT SHEEN I ha rihai "wo lua I CAT* LED-6 2EorS1.7C LED HOLDER iJ Two piece *-.c'd*r *■— "* fT% CAT* HLED 10 tor 65c RELAYS 12 VOLT D.C. COIL S.P,D,T, ORSenf C«2E-164P 4 AnpoDrrterii 335 ohm flOll. rC"^ Sugar OLfbeiiza. *1- X .42" X ,-u- rrtjh. Xl^—* 1 P.C. mount vrtlh pirn Ofl DIP •p*C-»g. CAT* RLY-7»? *l. 50 each S-6 VDC SIP REED HELAY EbctroJ -Blue Boy* SlA MQ sp3 MVde. SOOonrncoi. S.F.S.T. nofmtlly op*n read rtlny. C.5 unp KHItKl). SP (col .; ^ra'iiin TX J75'X J. CATt ifiLLT.l.li'i Sl.lOMd. ■ lOEorSICOO PHOTO FLASH CAPACITOR Rubyoon* FKX 200 mfd. 330 volts. 0.79" diameter ! Snider toop ternnEnals. CAT# PPC-200 $3.25 each 10 tor $30.00 • 100 for $275.00 K rx 1.11* high \ | 22/44 PIN CONNECTOR 'lliiliillilllllljli m ,r-i' .156" pin spacing, 0.200' between double rows, gold contacts. P.C. mounting. SPECIAL Same as AMP* 2-530655-6. CAT* EHC-1G $1 .00 each ■ 10 lor SB.00 SOUND AND VIDEO MODULATOR TU UM13B1-1. CW«o*d lo> ih wth T.L oumpulm. Can b* ua«d w*h v'tjta omra. oamt* or dhaf mudio/viBKi KKirca. Suit in A/B *wtten knablrM u**r La A Imn T.V. irtenr.1 wiftSoul rta«cnn*dcn. Opw«t«» on channtl 3 or 4. FUnuirH 12 Vdc. HocA up dvnrlMn InolurJvd. CATi A VMOD IS 03 it! LllltK WHAT (1 .1)0 WILL l)(i\ MO ASSORTED Z 1 ™! ^ B ^^ 114 WATT RESISTORS <> Bknl Ludc, DAjbon domp, and cjiitjori 1am. CAT* ORES $1.00 par aMorunaffl -P^ JJO"! 300 ASSORTED ■^^^ 1/2 WATT RESISTORS Bant htana. carbon crxnp and carbon MLm. CATt OflABRE V oa par aaaoXrnanl SO ASSORTED DISC CAPACITORS Moat ara cut rp.c iaada]. Soma IP S00 vplta CATS GttABDC S1.00 par AtaDUfnanl 15 VALUES OF — ELECTROLVTICS Contajna both axiaj and radial atylaa trpm 1 mfd. CAT# GHABCP S1.00 par aaaonrrwm fi! fl l 10 AMP SOLID STATE RELAY ELECTRQL* 52 lei CONTROL: Rd*d 5.5 rVj VO Vdc iw! ' cpwalat en 3-32 Vdc). ■ LOAD: 10 *irp ^ 240 V*n 2 1M* X l W X ?«■ CAT* SSHkY-IOrJ t4.M Hch OUANTirY DISCOUNT 10lorIS5.00 " 25lar»17&J» SOfor «300.CD »100ior $500.00 XENON TUBE Y bn-J ftutHutM L>'*oq*3 with 3 17 r*d and &*A i**d«. rouJ lor •iifdron.c Huh or itrnt>« r-"oi*cti. CATf FLT-a 2 lot »i. 00 LIGHT ACTIVATED MOTION SENSOR Tt->i ocvica Hmrlainf a phala&All Wtlk-h :r>-ji: iudd«n chang* in aimhient Irjhl. Could b4 uiKt ai « door an-j - -C\a\ 6! Of T>K tl &3 1o Erigoar ctiror d»wic*s. Gi^X4'Xi^0p*>-«tw on B Vdc Ft«quv*t 4 AA batlorrM (not indudod^ CAT* LSMD $5.75 par unrl 1/* WATT RESISTOR KIT IdtMf laMhfj*Orl-.trl.Op.lht ■ i4 wan r*,ir.-r>r kh conLikii 10 pUoh *ach t4 4? o* lh*i mow popular VaJuaa kV]20 ptocaa To- lal). IndudH a drvidtHf box and ■ pant locator,, VALUES la --a WOuU tail tat S21.00. CompW!* kit * CAT* REKtTvM S 17.00 9 PIEZO WARNING DEVICE Muina Eria « PKEB-J A0 MiQh pitched Jrudbl* alarm. Op- •ratat on 3 - SO Vdc ^ 20 rra. T high x 7/ff" dia. P.C board mppnt. CAT* PBZ-&* $1.76 aaoh NICKEL-CAD BATTERIES (RECHARGEABLE) SPECIAUI AAA SIZE 1.2 volO IMMAh CATf HCB AAAX St .50 aad 1DforSS3.50 * IOi3lofS1SSXX> AASEE IztBaach lis wria SOOmUi CAT! NCEL-AA AASEE 12.20 aach Wmt SOLCrcH TASS CAT* KCB-SAA C SIZE St.23 EACH 1.2 wptla 1200 mUi CATf HCB-C □ SIZE (4,S0a«h 1 2 nfta 1200 mAh CATf HCB.O TRANSISTORS CROEHBVPAHTf PN2222 NPN TCJ.9a SlorTSt PN2907 PNP TO-S2 5for75« 2N3055 NPN lOH $1.00 each MJ29S5 PNP Ti^3 $1.50 each MJE29SST PNP TO-220 75* each MJE3055T NPN TO220 75«each TIP31 NPN TO-220 75« each TIP32 PNP TO-220 75ttMCh TIP121 NPN TO-220 75eeach TIP126 PNP TO-220 75eeach TIL-99 PHOTO TRANSISTOR TOl$uu> wKh avindow. For wldc-angto viavring spp With TIL-3 1 B. CAT* TlL-flB SlOOoach * 10!cr|9.CO TIL-31B PHOTO DIODE TO-IBcaaawTlri wndow. nh-irrri nmin-,- ( -.hcio diodfj. CATlTlLJlB 1100 ea. » 10 for 16.50 N-CHANNEL MOSFET HF-511 TO-220 ea*a CATi IRF Sll «1.00aach' 10 far HUB L ARfJE QUANTITY AVAILABLE L.E.D. FLASHER KIT Two LE.D .» llaih in ^1/^ \|/ uni«ri whan a G vol ~\jf — ^A}* ^ ^ ~** *i taaiit-wr h aaachtd. ** *&v "\ T hi* U indudta a i -^ p£. board. *l |h* ®--^ parla and mir'jciw-ff;* to mako a. %ktq\9 ll»har df~ cut. A QU»cK and Aaiy praject lor anyanawilh baaic loader.^ tkiRa CAta- LEOKIT $i.?5 p-j- > TELEPHONE COUPLING TRANSFORMER MuM ProdUdi InlarrLalitKiaH A19MHO- lOfl Prlmaiy o00 ohm Svoondary- OXutWO ohm ,7T x ,er x .Bar rrioh. 6p.c. pins on .167- cvfdari. Prlmaiy inductance: SCO mH mlfl., H ihWt 1 vot CATtTCTX-l 11.25 each ■ 10 tor Jl 1 .00 OPTO SENSOR U ahapad packarja with mounting *air- irs- opaning. 3/4- mounltng i. CATi OSU^ see aach 1ornrf4.5Q - ^oorors*o.oo OPTO ISOLATOR StgmaJ 301T1-12S1. Signal apptad la iha Input ■ couclad by maant of light 10 larjtalKl photo eon- dudhra pall. High r^taUEKjr awltphlna. 12 votl input. CAT* OP-301 t1.50aach A.C. LINE CORDS Black aft. loV2,)S|.2 NONPOLARIZED PLUG CATILCAC 2 lor SI. 00 - 100 lor S4S.00 POLARIZED PLUS CATJ LCP-I KM aach - IOOtorSSO.00 14.7 VOLT TRANSFORMER Sprits Industries* C5-510A. 11.7 volt, e0hs.6-.S2 Vs. 1^1-tilQtiX1j95*X 1 .47". Mounting notes on 2.32- osnteit. CAT# TX-147 $3.00 each 10 for $27,00 • 100 for $250.00 CALL OR WRITE FOR OUR FREE CATALOG OVER 4000 PARTS! Now 60 pages MAIL ORDERS TO: ALL ELECTRONICS P.O. BOX 567 VAN NUYS, CA 91408 TWX-S1010101S3 (ALL ELECTRONIC) OUTSIDE THE U.S.A. SEND $2.00 POSTAGE FOR A CATALOG!! ORDER TOLL FREE 800-826-5432 INFO: (818)904-0524 FAX: (818)781-2653 MINIMUM ORDER $10.00 QUANTITIES LIMITED CALIF. ADD SALES TAX USA: $3.00 SHIPPING FOREIGN ORDERS INCLUDE SUFFICIENT SHIPPING. NO C.O.D. CIRCLE 107 ON FREE INFORMATION CARD 105 106 CIRCLE 113 ON FREE INFORMATION CARD DFAI FRRnnn.E 17(1 DN FRFF INFORMftTinN TABn 4800/2400 BAUD FAX/DATA MODEM FAX TRANSMISSION ONLY 4S00 BAUD FAX CAPABILITY TO ANT GROUP III FAX £400 BAUD V.22SIX DATA MODEM' XT/AT COMPATIBLE HALF CARD MENU-DRIVEN SOFTWARE MULTIPLE FAX TRANSMISSIONS TO GROUPED ADDRESSES MCT-FAXM •S a ' 2400 BAUD MODEM *89 95 ■ 24QQH 200/300 BAUD ■ FULL HAYES COMPATIBILITY ■ CONFIGUREASCOMl.COM?, COM3 OR COM 1 • BUILT-IN SPEAKER • AUTO WArT- FOB-DIAL TONE AND AUTO-REDIAL * PROCOMM COMMUNICATIONS SOFTWARE • MADE IN THE USA MCT-Z4I MCT-121 1200 BAUD INTERNAL MODEM 159.95 MINI UPRIGHT CASE & 249 95 SMALL FOOTPH INT M INI- UPR IGHT FOF M 80BB OH MINI 2B8/3B& MOTHERBOARDS - HOOM FOR 6 EXPANSION CARDS . HOLDS 3 5- 1M £ 1 3-1J2 DRIVES (1-/2 HT| - 200 WATT POWER SUPPLY • Z-DIGITLEDSPEEDDISPLAY M - 12-HXlG-LXa'W CASE-120 UPRIGHT CASE $2BB 9B SPACE SAVING DESIGN HOLDS » ALL SIZES OF MOTHERBOARDS AND INCLUDES: • 250W POWER SUPPLY - MOUNTS FOR 3 FLOPPY £ 4 HARD DRIVES ■ TURBO 4 RESET SWITCH • LED SPEED DISPLAY • POWER 5 DISK LEO'S - ALL HARDWARE, FACEPLATES S, SPEAKER CASE-10Q CASE-FLIP FOR SOBS MBS S39.95 CASE-SLIDE FORRoeeMB's $39,95 CASE-70 FOR2B6 MBS $89.95 CASE-50 FOR MINI 236 MBS ., $59,95 CASE-JR MiN I-28S wn 50W PS $ 1 49.95 MODULAR PROGRAMMING SYSTEM MODULES USE A COMMON HOST ADAPTOR CARD- T SLOT PROGRAMS SPROMS, PROMS, PALS. MORE! HOST ADAPTOR CARD $29.95 ■ UNIVERSAL INTERFACE FOR ALL PROGRAMMING MODULES' ■ SELECTABLE ADDRESSES PREVENTS CONFLICTS ■ MOLDED CABLE MOO-MAC UNIVERSAL _ MODULE $499.95 ■ PROGRAMS EPROMS. EEPROMS, PALS. BI-POLAR PROMS. B74SS B751 SERIES DEVICES; 16V8 AND 20V8 GALS (GENERIC ARRAY LOGICJFROM LATTICE. NS. SGS - TESTS TTL, CMOS, DYNAMICS STATIC HAMS ■ LOAD DISK. SAVE DISK, EOFr. BLANK CHECK. PROGRAM. AUTO. READ MASTER. VERIFY AND COMPARE - TEXTOOL SOCKET FOR X -6TW. IC'S ( 8-40 PINS) MOD-MUP EPROM MODULE $119.95 ■ PROGRAMS 24-32 PIN EPROMS. CMOS EPROMS S EEPHOMS FHOM 16KTO10!4K - HEX TO OBJ CONVEHTEH -AUTO. BLANK CHECK/FROG RAM/VEHIFY ■ VPP5. 12.5. 12.75. 13.21 8 25 VOLTS ■ NORMAL. INTELLIGENT. INTERACTIVE & QUICK PULSE PROGRAMMING ALGORITHMS MOD-MEP MOD-MEP-4 4-EPROM PROGRAMMER .... S169.S5 MOD-MEP-8 S EPROM PROGRAMMER S259.95 MOD-MEP-16 15-EPROM PROGRAMMER $499,95 OTHER MODULES MOD-MPL PAL MODULE $249.95 MOD-MIC DIGITAL TESTER MODULE $129.95 MOD-MBP BI-POLAR PROGRAMMING MODULE $259.95 MOD-MMP MICROPROCESSOR PROG. MODULE .... $179.95 MOD-MPL-SOFT CUPL SOFTWARE $99.95 VGA COMPATIBLE I ; — I PACKAGE $49995 ■ 720 X 540 MAX RESOLUTION. ifl 640 X 480 IN 16 COLORS, 528 X 480 RESOLUTION IN 256 COLORS ■ IBM STYLE MONITOR ■ VGA, EGA, CGA, AND MGA COMPATIBLE VGA-PKG IINCLUCES VGA CARD AND MONITOR) VGA MONITOR $359.95 ■ 14- ANALOG VGA ■ GLARE RESISTANT SCREEN • 720 X JSO ■ TILT/SWIVEL BASE ■ FRONT MOUNTED POWER SWITCH VGA-MONITOR fCREiLISYS MULTISYNCH $429.95 ■ FULL FEATURED MULTISCAN MONITOR WITH UNLIMITED COLORS ■ 1024 X 768 RESOLUTION, 14" NON- GLARE DISPLAY ■ AUTO SWITCH I MG • TTUANALOG VIDEO INPUT JDR-MULTI | EGA SPECIAL! CARD t MONITOR-JUST S479 L EGA-MONITOR 14- RGB MONITOR..... $339.95 NEC-MULTI-3D DIGITAL 1024X760 RESOLUTION ... $649.95 JDR-MONO 12" TTL MONOCHROME- GREEN $69.95 JDR-AMHER 1 2" TTL MONOCH ROME-AMBER $69.95 ^ttbtttTA -IdHal'tU QUALITY ■YBOARDS STANDARD KEYBOARDS: BTC-5060 AUTOSENSE FOR XT/AT S59.95 MAX-5060 WITH TACTILE FEEDBACK $64.95 ENHANCED KEYBOARDS: BTC-5339 AUTOSENSE FOR XT/ AT. AUTOREPEAT $69.95 K1 03-A AUDIBLE "CLICK - STYLE $84.95 MAX-5339 MAXI-SWITCH WfTACTILE FEEDBACK $34.95 MODULAR CIRCUIT TECHNOLOGY DRI VE CONTROLLERS: MCT-FDC MCT-FDC-HD MCT-HDC MCT-HLL MCT-FH MCT-AFH MCT-AFH-RLL FLOPPY DISK CONTROLLER 1 .J4MB FLOPPY CONTROLLER HARD DISK CONTROLLER RLL CONTROLLER FLOPPY/HARD CONTROLLER 2B6/3B6 FLOPPY/HARD 26S/336 RLL CONTROLLER D1SPIA Y ADAPTOR CARDS: MCT-MGP MCT-CG MOT-EGA MCT-VGA8 MCT-VGA-16 MCT-MGMIO MCT-MGAIO MONOCHROME GRAPHICS COLOR GRAPHICS ADAPTOR ENHANCED GRAPHICS ADAPTOR B-BIT VGA. ANALOG OUTPUT 16-BIT VGA. ANALOG OUTPUT MONOGRAPH ICS MULTI I/O 286/586 MONOGRAPHICS I/O MULTIFUNCTION CARDS: MCT-MIO MU LI I I/O FLOPPY CONTROLLER MCT-IO MULTI l/OCARD MCT-AMF 286/386 MULTIFUNCTION MCT-AtO 2S6/3S6 MULTI I/O CARD MEMORY CARDS: MCT-RAM 576K RAM CARD MCT-EMS EXPANDED MEMORY CARD MCT-AEMS 286/356 EMS CARD $29.95 $49.95 $79.95 $89.95 $139.95 $149.95 $199.95 $59.95 $49.95 $149.95 $169,96 $249.95 $119.76 $99.95 $79.95 $59.95 $1 39.95 $59.95 $59.95 $129.95 $139.95 QgrihSoan 400 dpi $19995 - UP TO 400 DPI - 32 LEVELS OF GRAY SCALE ■ SPEED ' OVERRUN WARNING LIGHT ■ INCLUDES SCANEDIT II. PRODIGY OCR AND DR. GENIUS SOFTWARE GS-4500 PROGRAMS 27XX AND 27XXX EPROMS UP TO 27512 SUPPORTS VARIOUS PROGRAMMING FORMATS S VOLTAGES SPLIT OR COMBIN E CONTENTS OF • SEVERAL EPROMS OF DIFFERENT SEES READ, WRITE. COPY. BLANK CHECK S VERIFY SOFTWARE FOR HEX AND INTEL HEX FORMATS MOD-EPROM HARD DISKS KITS 21.4MB $ 199 21.4MB $ 249 32.7MB $ 219 32.1MB $ 279\ 42.8MB $ 339 65.5MB $ 389 80.2 MB $ S6i 8P Seagate tarn man 4 * 0, fam Bl " n *"™ 1 into factor amy XT Ktr/R KIT KIT 214MB ST-225 IeSMsIs-IM* SIM *249 $309 32 7MB RLL . ST.238 ' 65 MS 5 1.4" SI19 *279 $378 42SMB ST-2SI-1 1 28 MS ■ t S339 $389 $449 65 5M8RLL ST-2T7-1 28 MS 5 1/4- ttSB SJJ3 $549 80 2MB ST-4096 . 28 US 5 1 f WG9 — X679 122 7MBHLL STJ144H 28 ms 5 1/4- S693 $759 $299 5359 $373 214MB ST-IW K MS 3 \nr 5359 32 1MB RLL ST- 138 40 MS 3~irr $269 , *339 $429 ^ 157.5MB ESDi K m ^ At ^ DRIVE KTT xu 4i f - 5-i:4- HARD DISK, PLOPPr/HARO CONTHOU.ER, CABLES. MOUHTING HAROWARE & SOFTWARE. 1355-PKG 1.44MB 3-1/2" DRIVE $9995 ps ■ULTRA HIGH DENSITY • READ/WRITE 720K DISKS. TOO . ""H^-. FDD-1.44X BLACK FACEPLATE ^^> FDD-1.44A BEIGE FACEPLATE FDD-1 44SOFT SOFTWARE DRIVER $19.95 1/2 HEIGHT FLOPPY DISK DRIVES: FD-55B 5-1/4- TEAC DS/DD3S0K $99,95 FD-55G 5-1/4- TEAC OS/HO 1.2M $129.95 FDD-36C 5-1/4-DS/DD360K $69.95 FDD-1.2 5-1/4- DSHD 1.2M $95.95 MOTHERBOARDS 20MHZ3S6 $6QQ ' • 16H20MHZ t*«^«* - 16MBRAMCAPACITY-8MB ON BOARDfeK). B MB RAM CARD - USES 256K OR 1 MB SIP RAMS • 8SLOTS: 1X32-BITRAM 2X 8-BIT S 5X 16-BIT ■ MEMORY INTERLEAVING ■ AMI BIOS ■ XT SIZE BOARD MCT-M386-20 MCT-C386-26 25MHZ MINI 385 W/CACHE ..$1499.00 MCT-M386-M 8MB RAM CARD OK) $149.95 MCT-3B6MB20 10/20MHZ386 $799.00 MCT-3B6MB25 I0/25MHZ386 $999.00 MCT-3B6-M 8MBRAMCARD(OK) $149.95 10MHZMINI-286 *199 9S ■ AT COMPATIBLE - KEYBOARD SELECTABLE 6/1 0MH2 - EXPANDABLE TO 4MB ON-BOARD WITH 1MB DRAMS J0K) • SIX 16-BIT, TWO 8 BIT SLOTS • AMI BIOS ■ LED SUPPORT MCT-M2B6 MCT-M2S6-12 BZ12MHZ MIN 1-286 $249.95 MCT-M2B6-16 S/16MHZ2B6 $369.95 MCT-M2B6-20 10.OTMHZ286 $429.95 MCT-XMB STANDARD 4 77MHZ80BB $87.95 MCT-TURBO 4.77/8MHZ 8088 $95.96 MCT-TURBO-10 4.77/1 0MHZ SINGLE CHIP 8088 $99.95 EPROM PROGRAMMER $129.95 W f&. • PROGRAMS 27XX AND 27XXX EPROMS UP TO 27512 I ki i Loci.iici: LOGC9 LOGC9- LOGC9 L0GC9- LOGS9 LOGS9- LOGS9- LOGITECH MICE ■ THREE- BUTTON SERIES 9 »* •320 DPI RESOLUTION - SERIAL PS/2 COMPATIBLE. % ., SERIAL MOUSE JUL. $98.95 C* SERIAL (NOT PS/2 COMPATIBLE) $79.95 P SERIAL MOUSE WITH PAINTSHOW ... $109.95 PC SERIAL MOUSE WITH PAINT/CAD $154.95 BUS MOUSE $89.95 t> BUS MOUSE WITH PAINTSHOW $104.95 PC BUS MOUSE WITH PAINT/CAD $149.95 VISA JDR MICRO DEVICES, 2233 BRANHAM LANE. 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HTL, MINIL MOS. & CMOS COMPATIBLE LP-540 *54 95 JIM'S BARGAIN HUNTERS CORNER 108 Jfjrt WhprlOU JDP's VP Sales SAVE UP TO 63% ON FACTORY REFURBS MULTH/O WITH $3Q95 FLOPPY CONTROLLER ^^ IFHEWS7S.9S SUPPORTS 2 FLOPPIES. SERIAL. PARALLEL AND GAME PORTS. PLUS CLOCWCALENDAR MCT-MIO EXPIRES 12(31189 MONOGRAPHICS $^Q95 PRINTER CARD «K %F IF NEW $79.95 720 X34S DISPLAY. SERIAL PORT OPTIONAL MCT-MG EXPIRES 12/31/89 JDR Microdevices 2233 BRANHAM LANE. SAW JOSE. CA 95124 ORDER TOLL-FREE 800-538-5000 LOCAL (403) 559-1200 CUSTOMER SERVICE 000 530-5001 TECH SUPPORT B0D-53B -50D2 FAX I -1 08 1 559D25D CIRCLE 113 ON FREE INFORMATION CARD DEALERS CIRCLE 170 ON FREE INFORMATION CARD ADVERTISING INDEX RADIO-ELECTRONICS does not assume any responsibility for errors that may appear in the index below. Free Information Number Page 106 AMC Sales 17 152 Ace Com mimical! cms 32 75 Ace Products 33 153 A1S Satellite ...,33 1(17 All Electronics 105 — Amazing Concepts 100 84 Appliance Service 33 67 Banner Technical Books 27 151 B F Electronics 90 109 C&SSales ? 34 70 CE1 98 — C1E 5,31 — Command Productions 17 58 Cook's Institute 24 127 Deco Industries 33 82 Digi-Key 104 135 Electronic Goldmine 95 — Electronic Tech Today CV3 — Electronics Bookclub 74 161 Emulation Associates 33 121 Fluke Manufacturing CV2 156 Global Specialties 25 — Grantham College 78 86 Heathkit 27 — Information Unltd 94 136 International Components Corp. . 9H 1 13,170 JDR Microdevices 106. 107 113,170 JDR Microdevices 108 114 Jameco 102 1 15 Jensen Tools 33 137 Jinco Computers 100 — Lindsay Publ 72 — McGraw Hill Hook Club 46 87 MCM Electronics 95 53 MI) Electronics 94 93 Mark V. Electronics 99 61 Microprocessors Unltd. 90 160 Movietime 24 — NR1 Schools 8 147,148 Optoelectronics 14, 97 — Pacific Cable .93 56 Parts Express 101 7N Radio Shack 13 149 Salen Enterprises 32 155,154 Scncore 23, CV4 138 Sequoia Pub 33 — Star Circuits 69 83 Synergetics 62 146 TAB Books [5 157 TECI 28 145,92 Tektronix 7, 18 158 Tentel 68 123 Test Probes 3 250-254 Test Probes 3 64 Video-Link 96 143 Viejo Publications 32 144 WPT Publications 2S Gernsback Publications, Inc. 50O-B Bl -County Blvd. Farmingdale, NY 11735 1-516 293 3000 Fax 1-516-293-3115 President: Larry Steckler Vice President: Cathy Steckler For Advertising ONLY 1 516-293-3000 Fax 1-516-293-3115 Larry Steckler publisher Arline Fishman advertising director Lisa Strassman credit manager Christina Estrada advertising assistant SALES OFFICES E AST/S OUTHEAST Stanley Levitan Eastern Sales Manager Radio-Electronics 259-23 57 th Avenue Little Neck, NY 1 1362 1-718-428-6037, 1-516-293-3000 MIDWEST/Texas/Arkansas/ Okla. Ralph Bergen Midwest Sales Manager Radio-Electronics 540 Frontage Road — Suite 339 Nin-tlifiukJ. IL 60093 1-312-446-1444 Fax 1-312-446-8451 PACIFIC COAST/ Mountain States Marvin Green Pacific Sales Manager Radio-Electronics 5430 Van Nuys Blvd. Suite 316 Van Nuys, CA 91 401 1-818-986-2001 Fax 1-818-986-2009 BUY BONDS Electronics Paperback Books GREAT PAPERBACKS AT SPECIAL PRICES □ BFl^J— COMPUTER music PROJECTS |S.9$- Shows hew (o use your homa compu'w to produce ••• - : l ■•• -:': i i . : ■ Many circuSs. Mostly jar- rjon tree i : 6P233— ELEC- PCPIQS-^PRACTICAL T ^L C " 0BBY,ST * hHDI MANDMOK . I HANDBOOK ».9S. M 95. Expta-ns what SJnfljoj Wf; <* "Ml* midi Mm Muscat tocaLfld info mat (ha afcc- rj^] 1n(fl rtBco> on do Irpnpa hoitysl needs in j^S (»* you can P«l iL his day-to-day pvrwi cJ to wic cwm this tascinallng hobby. Ke^oarda. drum mixers, guitar! and oompuler music. RFTD— FLAPtO'S FIRST TWO DECADES tLH. Tf« story of radios earfy dayi makes bf wctmeing reading. 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You'll prooflbly never need another book on this subjeel H HPIM— MfCRO IN- TERFACING CIRCUITS— BOOK 1 45,75, Practical add-ons transform your computer Into contraf or measure^ m#r>1 aquipinanl |~! SP1«-^NTFtO TO PROGRAMMES THE ATARI OOO/HH XL — . SS.95. Parted: 00rrtpa> manl » (ha Atari users manual. Even shews how 1*1 use. animated graphca. O BP1JI— MICRO IN- TERFACING GRCUfTS— BOOK S 15.75. Interfacing sound and 4p4*Ch generator*, temper alum and optical Sensor* , motor ccntrd- lara, and mora. " RADIO— 100 RADIO HOOKUPS 5300. Wtondartul reprifll C« this L j BP1S2— INTRO TO 7-» MACHINE CODE 15.K. Spaed up your programs-. Triay maw be homer to write, bul its tOQ sclwmalics ol radio Circuits 01 thai era. Trie anllQUfi radio kner vrill label Ihls one a "must are inducted.' I ; BP10S— ANTENNA PROJECTS ^ 15 JO. 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Learn hew tho 0£v3 operaling system is siructurod and how to use it effectively. Written with mo non^Wfpwi busy person inmrnd. ! BPeO— POPULAR ELECTRONIC CIR- CUTTS. Beoc 1 .... tSsS- Mora circuits tor hoo- byists. Aud«o, radio, laaL, must, howaehofo and more. □ BPSe— POPULAR ELECTftONK CIR- CUTTS. BOOK 3 55 .95 Mom useful ■■;■ •■ Culls. None of maee projects dutficala Trioaa In Book 1 ot this series ELECTRONIC TECHNOLOGY TODAY INC. PO. Box 240, Massapequa Park, NY 11762-0240 Name Address . City SHIPPING CHARGES IN USA AND CANADA _State . -Zip. $0.01 to $5.00 . $5,01 to 10.00 . S10.01 to $20.00 120.01 to $30.00 $30.01 to $40,00 $40.01 to $50.00 .$1.25 .$2.00 .$3.00 .$4.00 .$5.00 .56.00 SORRY, No orders accepted outside at USA and Canada Number of books ordered | I R-190 $50.01 and above .$7.50 Total price of merchandise S . Sales Tax (New York State Residents only) t . Shipping (see chart) $ _ All payments mutt be In U.S. fundi Total Enclosed . . t . 1 ~^^ w Introducing The SG80 AM Stereo- FM Stereo Analyzer ™ Now For The First Time, A High-Performance AM Stereo (C-QUAMf - FM Stereo Analyzer Integrated Into One Unit, Allowing You To Performance Test, Troubleshoot, And Align To Manufacturers' Requirements \ .fjfc- *Tl«MJ vf .W output Uvel^^^b, no • FREQUENCE ^MH| W'fc - isaiall ■■-» ~ m.oriiioawTioN .mm"""" „,»»»« ,,;- |k ..-|.' «»' >J^M^ 11 Patented Licensed Under Motorola Patent No. 4^278,586 Complete AM Stereo-FM Stereo Analyzer— exceeds manufacturers' requirements. Patented FM analyzing signals isolate any FM receiver defect. Exclusive integrated AM Stereo C-QUAM analyzer. Digitally accurate performance tests meet EIA/IHF requirements. Exclusive, tuneable FM-IF Sweep and Markers— aligns alt IF stages. Expandable FM features for future service needs, plus SCA compatible. Twice the capability for less than 1/2 the cost of stand-alone instruments. 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