The best 60MHz scopecosts only $1100.It's fromKikusui.That's right. Only$1100 for Kikusui'stop-of-the- line 5060 model oscilloscope, And we alsohavefour other scopes for as low as $600 in our new 5000 Series,Not only that. we're offering a two year warranty on each of them, compared to other bigname companies' limited one year warranties,Whenit comes to performance, our 5000Series has the edge over the Tektronix 2200 Seriesin lab quality, chop frequency, and trigger view. Ours also have moredisplay modes, higheracceleration for better brightness, and sharper focusfor better resolution,Each scope in our 5000Series is crafted so that it can be used for production, field service,consumer electronics servicing, or even personal use.The 5060isa 60MHz scope with 3 chan-nels, eight traces, delayed sweep, delay line and alternate sweep, and priced at $1100, Models5040 and 5041 are40MHz, dual channel scopes, featuring peak-to-peak automatic trigger-ing, automatic focuscontrol and adelay line, If you're interested in a20MHz scope, wehaveour 5020 and 5021 modelswith features similar to our 40MHz scopes, Both the 5041 and 5021alsohave delayed sweep. Prices at $920 for the 5041,$795 for the 5040, $690 for the 5021and $595 for the5020, So, whatever model suits you best. you can't get abetter scope forthemoney.Of course, there's areasonwe're able to offer thesebargains and quality, We're one of thebiggest manufacturers of scopes in the world. with over 30 years in the business,Another reasonis KIK's nationwide network of lab quality maintenance facilities.Write us and we'll sendcomplete specifi cations back to you. Or just take alittle time to cal lus. It's asmall price to pay to get big timequality and service,For sales andtechnical informationcall toll free 8004215334(in Calif.,Alaska, Hawaii 213-515-6432).~KikuSUI- 17819 RgueroaStreetGardena. Calif, 90248TWX. 910-346-7648INTERNATIONAL CORP. .. In Canadacall: InterfaxSystems. Inc, 514-366-0392SUb Sl d lo ry of Klkusul Elec tronic s Corp . 3-1175 Srunmoruko-Hlgashl, Nokonoru.ku. Kowc sokt Ci ty,Ja pan (044) 411-0111CIRCLE7 ON FREE INFORMATIONCARDOrder TollFree800-421-5334I VISA"ISleepSafeGives youaSMOKE DETECTOR. . .a nALARM CLOCK. . .a nEMERGENCY BEACON. . .a ndaportable FLASHLIGHTall in onecompact unit.omoms:1Ilm:DPRODUCTSOFTHE FUTURETODAYIf, f oranyreason, whatsoever, you'r enot 100%satisfied, j ust returnit initsorig inal boxforacourteousrefund.SLEEPSAFE isinexpensive enough toput one in every sleepin g room in yourhome - especiall y c overi n g thec hildren' s rooms, SLEEPSAFEg ivesyou peace-of -mind for older fo lks, too,the ha ndi c a p p ed . . . col lege dormstudents ... any lovedoneat home oraway. It' s simplyth e most practical,helpfu ltravelingcompa n i o nyou'lleverytakealong.SLEEPSAFE is an ideal Christmas gift.One th at w illmakeboth youandyourl o v ed ones sleep e asier, order aSLEEPSAFEtoday.SEICONSUMERPRODUCTSDIVISION912 West Touhy Avenue,Park Ridge, IL60068Cal l Tol l Free(Orders Only) (800) 323- 1327For Informat ionCall (312)564-0104W e'll shi p you your SLEEPSAFE w it hi none week of our receiv ing your orderor we'll paythe shipping.SLEEPSAFEc ontainsanemergencybeacon l i ght , w h ichautomati c a ll yli ghtsd uringemergencies,andhelpspoint the way to safety. The light st aysonunti l the air is c leared, it can also bemanually turnedon or off.Try one, t here's no r is k. Send yourc heck or money order for $ 3 9 .9 5plus$3.00 postageandhandling. (Ill inoi s 'residents add 6%sales t ax .) On lycredit card buyerscan usethetoll-freenumber g ivenbelow. Guaran-teed quick delivery.Thenewsflashbroke." Tr ag i cfireinLas Vegas ki lls over 100 people s leep-ing i n t heir hot el rooms." The f irealarms didn't work! It was a tragicevent; thosepoorpeople never wereawaken. They s imply never had achance.Th est atisti c saren'tp leasant, they'res hocking! 700,000homes, hotelsandhi -ri ses goupin f lameseveryyear.SLEEPSAFEcanim prov eyour odds.Not on ly does SLEEPSAFE protect youeverywhere, but it'scompletelyport-able andneeds nowiresor installa-t ion.SLEEPSAFEstores compactl y in it sowncase. Detects smoke and wakesyouwithapiercing 85-decibel alarm.It' s extremel y sensitivebut speciallyd esi gned to minimize fa lse alarms.Battery operated - (batteries in -c luded) completelyi nd e p en dent ofany outside power source.SLEEPSAFE also contains its ownslide-out, slide- in , five function LCDModular A larmCloc k . T h e digitalr ea d out incl u d es alarm, snooze -alar mandb ac kl it e. Batteryoperated(batteriesinc lud ed ).CIRCLE 14 ONFREEINFORMATION CARDWhy use other computer mediawhen you could be usingMEMOREXhigh qualify error tree media?NewMemorexLi fet imeRig idDi sc PackProduct WarrantyAll Memorex disc packs sol d by CE havea lifetime product warranty.This is your assurance that Memorex di sc packs will give you a lifeti meof performance and service. Only Me morex can offer you the superi orreli ability of th eir exc lusive M Formul a. In addit ion, Memor ex will assistt heor igi nal userinisolati ng andcorrect ing any t echnical issues thatrelat e t o theMe morex product as we ll as, when appropriate, replac eup to oneset of read/ wr ite heads. If youneed further information t o findthe rigi d di sc t hat's right foryou, call t he Memorex rigid disc compatibil-ity hot line. Dial tol l-free800-538-8080 and askfort he rigi d disc not tineextension 1642. InCaliforniadial 800-672-3525extension 1642.Outside the U.S.A. dial 408-987-1642.65.00-70.00160.00160.00330.00320.00720.00560.00560.00515.00515.00795.00670.00365.00300.00315.00315.00825.00725.00CEquant.onepriceper pack (S)Ad #090282ParI #COMPUTER TAPEDISCCARTRIDGES RIGID DISCSFLEXIBLE DISCSSAVEONMEMOREXRIGID DISC PACKSProductDescript ionComputer Products DivisionBuy with ConfidenceTo ge t the fas test delivery f romCEof your Memorex computerpr od ucts, send or phone your order di rectl y to our Computer ProductsDivision. Be sure to calculate yo ur price using t he CE prices in t hi s ad.Michiganresident s please add 4% sales tax. Writt en purchase or dersareacc epted fromapprovedgov ernment agenciesand mos t wellrat ed f irms at a 30%surcharge f or net 30 bill ing. All sal es are sub ject toavailability, acce pt anceandver ifi cat ion. All sal esare final. Prices,term s and specific ations are subject to change without notice. Out ofstockitemswi ll beplacedonbac korder aut omat icallyunl essCEisinst ruct ed diff er entl y. Minimumprepai d ord er $50. 00. Minimumpurchas e order$200.00. lnte rnat ional orders are invite d with a$20.00surcharge for special handlinginaddi ti onto shipp ingcharges. Allshi pments are F.O.B. AnnArbor, Michigan. NoCOD'splease. Non-certif iedandforei gn checks requi rebank clearance .For shipping charges add $8.00 pe r case or part ial-case of 1008-inch f lexi bledi scsor$6 .00per caseor part ial caseof 100 5V,-inchmini-di scs . For t ape shipping, add $1. 00 per reel. For Di sc packs add$10. 00per cart ridg e (Mark III or CMD-16) or $1 5.00 per disc pack forU.P.S. groundshippingandhandli ngi n thecont ine nt alU.S.A.Mail orders to: Communi cati onsEl ect ronics,Box 1002, Ann Arbor,Mi ch igan 48106 U.S.A. If you have a Mast erCard or Visa card, youmaycall and place a credit cardorder. Orde r toll-free. Di aI800- 521-441 4. Ifyou are outside the U.S. or i n Michigan, di aI 31 3- 994-4444. Order yo urMemorex co mputer products fromCE today.Copyright 01982 Communications ElectronicsNMark III 5 M8. Cartridge Front Load (8 to 32 Sect.) 95522XX-03Top Load (Ho 24 sectors) 94522XX03CMD16 " Phoenix Type" CDCCartridge 98'26600-31NCRCartridge 982660032Mark VIII 80 MB. Error Free 721660003Flag Free 72-26600'03Mark XI 200 MB. Error Free 0335041Flag Free 03'35031-02DECFlag Free 033503103Mark XII 200 MB. NCR/CDCFlag Free 033900101Honeywell Flag Free 033900001Mark XIII 300 MB. Error Free 0347021Flag Free 03-47009Mark XIV80 MB. Unformated Error Free 74-16600-03Flag Free 74-26600-03Honeywell Format Flag Free 74-26600'08CDCFormat Flag Free 74'26600-09Mark XV300 MB. Error Free 0349011Flag Free 0349001 01Smith-Corona TP-1 Letter Quality Printer Special OfferBuy anyMemorex product onthis page,andget aSmith-CoronaTP-l letterqualityprinter for only $585.00 plus $20.00 shipping. Specify serial or parallel version. ..ELECTRONICS...10 Order Toll-Free! MEMOREX(800) 521-4414InMichigan (31 3) 994-4444CEquant.100 priceper dosc (S)CEquant.100 priceper reel (S)Part #Part#25JW 13.9925 JR 14.9925 FW 10.6527 JW 16.2027J R 16.9927FW 12.5039 JW 18.9939J R 19.99 854Phoeni x0 Bo x 100 20 Ann Arbor, Michigan 48106 U.S.A.39 FW 13.99 Call TOLLFREE (800) 521 4414 or outside U.S.A. (313) 994-4444CIRCLE 12 ON FREE INFORMATION CARD VE on 14EAfOnEX FLEXIBLE DISCSProduct Des cript ionSAVE 0 .'1MEU OREX COMPUTER TAPEProductDescriptionMemorex IV 2400feetWrightline SealMemorex IV 2400 feet Easy Load II CartridgeMemorex IV 1200feet Wrightl ine SealMemorex Ouant urn 2400feet Wrightline SealMemorex Quantum2400feetEasy Load 11Cart.Memorex Quantum 1200feet Wrightli ne SealMemorex CubicHO 2400feet Wrightline SealMemorex CubicHO 2400feetEasy LoadIIMemorex CubicHO 1200feet Wright lineSeal8" SSSD IBMCompatib le (1288/S, 26Sectors) 3062 2.098" SSSD Shugart Compatible, 32Hard Sector 3015 2.098"SSSD CPT 8000 Compat ible, Soft Sector 3045 2.998"SSDD IBM Compatible (1288/S, 26 Secto rs) 3090 2.748" OSDD SoftSector(Unformatted) 3102 3.348" DSDD Soft Sector (1288/S,26Sectors) 31 15 3.348" DSDO Soft Sect or (2568/S, 26Secto rs) 3103 3.348" OSDOSoft Sector (5128/S, 15Sectors) 3114 3.348" DSDD Soft Sect or (10248/S, 8 Sectors) 3104 3.345Y." SSDOSoftSector w/HubRing 3481 2.345Y." SSOD 10Hard Sectorw/ Hub Ring 3483 2.345'1, " SSOO16Hard Sector w/ Hub Ring 3485 2.345Y." OSDO Soft Sector w/ Hub Ring 3491 3.095W ' DSOO10Hard Sectorw/ HubRing 3493 3.095Y." DSOD 16Hard Sector w/ Hub Ring 3495 3.095'1, " SSQO Soft Sectorw/Hub Ring (96 TPI) 3504 2.9951f4" DSOO Soft Sect or w/ Hub Ring (96 TPI) 3501 3.99SSSD=Single Si ded Si ngle Densi t y; SSDD =SingleSided DoubleDensity;DSDD=Doubl e Sided Double Densit y; SSQD=Single Sided Quad Density;DSQD =Double Si ded Quad Densit y;TPI =Tracks per inch.Spa c ia l offer onMemorex computer t ape.If you mail your order to us and enclose prepayment, deduct $1.00perreel fr om our quant ity 100 prices. Thismeans Me morex 25JW can beaslowas$12.99i n100quanti ti es. Me morexComputerTapesarepac ked10tapes toa carton. Please ord er onlyinincrements of 100un its for qu antity100pricing. Qua ntities lesst han100 unit sareavai lablein increment s of 10 unitsat a10%surcharge. Qu ant itydiscountsarealsoavai lable. Order 500or more tapesat thesamet ime and deduct 1%; 1,000 or more saves you 2%; 2,000 or more savesyou 3%; 3,00 0 or more sav es you 4%; 4,000 or more saves you 5%and5,000or more tapes earns you a 6%discount offoursuperlowquantity100 price. If you need furt her assistance or i nformation tofi nd the tapet hat's right for you, call th e Memorex Computer Tape Techn icalSupport Group at (408)987 -2937.Fr eeMomorex Mini-Disc Offer- Get freediscs!You' ll save money when youbuy Memorex, because every carton of 10Memorex 5% inch mi ni-discs sold by Co mmunicat ions Elect ronics hasa coupongood f or a f reeMe morexmini- di sc.For every caseof 100Memor ex mini-di scs youbuy fr om CE, you ' ll ge t 10 freeMemorex mini -discs, direct ly fromMe morex. The mor e yo u order, t he more you save .OfferexpiresDecember 31 , 1982. All Memorex fl exi bl e discs sold byCE are of t he highest qual ity, certified 100%error f ree and backed by afull on e yearfact ory warranty.Fl exibl eDi scQu antity Discounts AvailableMemo rex Flexible Di scs are pac ked 10 discs to acartonand 10cartonstoa case. Pleaseorder onlyini ncrementsof 100unitsforquantity 100 pricing. We are also wi lli ng to accommodate yoursmallerord er s. Quant iti es less th an 100unit s are availab le in incr ements of 10unitsat a10%surc harge. Qua nti t ydisc o untsarealsoavailabl e.Order 500or morediscs at t hesameti meanddeduct 1%;1,000 ormor e saves you2%; 2,000 or more saves you 3%; 5,000 or more savesyou 4%; 10, 000 or more saves you5%; 25,000 ormore saves you 6%;50 ,000 or more saves you7% and 100 ,000 or more di scs earns you an8% disco unt off our super low quantity 100 price. Almost al l MemorexFlexible Discsar eimmediatelyavailablefromCEo Our warehousefacil it ies are equipped tohelp us get yo u t he quality product youneed,when you need it. If yo u need furt her ass istance to findth e fl exibl e discth at' s right for you, ca ll the Me morex fl exible di sc co mpatibi lity hotline.Dial toll-free 800-538-8080 and ask for th e fl exibl edisc hotlineextension 0997. InCali fo rniadial 800-672-352 5 exte nsion0997.Outside the U.S.A dial 408-987-0997 between9 AMt04 PMPacific Time.(J)aZoa:f-aw...JW6is-ca:2Electronicspublisherssince1908THEMAGAZINEFOR NEWIDEASINELECTRONICSDecember1982 Vol. 53No. 12Asa service toreaders, Radio-Electronicspublishesavailable pl ansor informationrel atingtonewswort hyproducts, techniquesandscien tif icandtechn ol ogical develop ment s.Because of possibl e variances i n thequalityand conditi on of materi al s andworkmanshi p usedbyreaders , Radio-El ect roni csdisclaims anyresponsibility for th e safe and properfun ct ion ingof reader-builtproj ect s based uponor fromplansorinf ormati onpublishedinthi s magazine.SPECIAL FEATURES 51 VIDEOENTERTAINMENT52 VideoEntertainmentin thehomeA. Lewis55 Direct Broadcast SatelliteTel evision.DannyGoodman59 NewVideo Components.DannyGoodman63 VideoAccessori es. GordonMcComb67 Howt oConnect Vide oComponents .GaryMcClell anBUILDTHIS 43 AUTOMATICCOMMERCIALEDITORMake commercial-freetapes ofyourfavorite old black-and-whitemovies. GaryMcClell anTECHNOLOGY 4 VIDEOELECTRONICSTomorrow's newsand technologyin this quicklychanging in-dustry. DavidLachenbruch10 SATELLITEfTELETEXT NEWSThe latesthappenings in communications technology.GaryArlen90 STATEOFSOLIDSTATEAn all-electronichumiditymeter. RobertF. ScottCIRCUITSAND 47 ETCHYOUROWNPC BOARDSCOMPONENTSMaking your ownPC boards iseasier thanyouthink. Here arestep-by-step instructions fromamaster.RobertGrossblatt75 HOW TODESIGNANALOGCIRCUITSIncreasing circuit gain. Mannie Horowitz84 NEW IDEASLow-batteryindicator.100 HOBBY CORNERReaders to the rescue. Earl " Doc"Savage, K4SDSVIDEO 94 SERVICECLINICGround-returnproblems. JackDarr94 SERVICEQUESTIONSR-E'sServiceEditor solves technicians'problems. JackDarrCOMPUTERS 80 COMPUTERCORNERSelectinganaccountingpackage. LesSpindleEQUIPMENT 26 MFJModel 1020ActiveAntennaREPORTS 30 SanwaLCD-900Multimeter32 SmithCorona Tpl Daisy Wheel Printer40 Non-Linear SystemsTR-l SignatureAnaly serDEPARTMENTS 136 Adverti sing Index8 Adv ertisingandSal esOffices137 FreeInformationCard20 Letters103 Market Cent er85 NewLi terature98 NewProd uct s8 Publi sher 's Letter6 What' sNewsSEASON'SGREETiNGSThe editorsand staffof Radio-Electronicsjoin in sendingholiday greetings andourbest wishes fora happy new yearON THECOVERIf you like to tape those vintageblack-and-white moviesthat showup late at night on TV-but don't liketo tape the commercials that accom-pany them-this automatic corn-mercial editor is for you! It watchesthe movie along with your VCR and,when a commercial turnsup, stopsthe tape until the movie beginsagain. Theresult isatapeof themovie, and nothing else. It's easy tobuild, and will. ..literally...provideyouwithhours ofpleasure. Get startedbuilding your owneditor.Plans be-gin onpage 43.Radio-Elect ronics, (ISSN 0033-7862)Published monthlyby GemsbackPublications, Inc., 200Park Avenue South,New York, NY10003. Second-Class Postage Paid at NewYork. N.Y. andadditional mailingoffices. One-year subscrip-tionrate: U.S.A. andU.S. possessions.$13.00, Canada,$16.00. Other countries, $20.50 (cash orders only, payablein U.S.A. currency.) Single copies $1.25. ~ 1982 by Gems-back Publications, Inc. All rights reserved. Printed in U.S.A.Sub scription Servic e: Mail all subscr iptionorders,changes,correspondenceandPostmasterNoticesof un-deliveredcopies (Form3579) toRadio-ElectronicsSub-scription Service, Box 2520, Boulder. CO 80322.Astampedsell-addressedenvelopemust accompanyallsubmitted manuscripts andor artwork or photographsif theirreturn is desired should they be rejected. We disclaim anyresponsibility for the loss or damage of manuscripts andorartworkor photographSwhile in our possessionor otherwise.ornorns::OJrnJJ3VIDEO ELECTRONICSDAVIDLACHENBRUCHCONTRIBUTINGEDITOR(f)ozoc::f-oUJ...JUJois-cc::4STEREO TVHITSSNAGBANK-BY-TVThe dreamof stereophonic soundfor televisionin 1983 vanishedin a puff of hostile smokewhen an industrywide committee studying the subject went back to the drawing board insteadof recommendinga system. Since1979, a subcommittee of EIA'sBroadcast TVSystemsCommittee has been examining and testing three proposed multichannel TV sound systems.Each of the systems-proposed by EIA of Japan , Telesonics SystemsInc., and Zenith RadioCo.-metthesubcommittee'sbasiccriteria : (1) StereosoundqualitycomparabletoFMstereo.(2) An additional "picture-related" sound channelfor such uses as foreign-languagetranslation. (3)Compatibility withexistingmonophonic-soundreceivers.The subcommittee completed its tests of the three systems on time, and its timetable calledfor it to select a system for recommendation to the FCC in mid-October. Everything was goingaccording to plan when the subcommittee's steering committee met to tally members' votesfor a system. However, it was confronted unexpectedly by a charge from Telesonics Systemsthat thetests were incomplete. Telesonicsrequested that thesubcommitteereopenitsrecord-and implicitly threatened legal action unless the subcommittee agreed. Accordingly,the subcommittee decided to reopen the entire subject to cover the Telesonics objection,aswell asanotherproblem. That newproblemrelatedtothediscoverythat most cable-TVsystems would be unable to relay stereophonic sound under any of the systems,and, in fact,thepresenceof a stereosignal coulddisrupt thecarriageof monoprogramsoncablebycausingadjacent-channel interference.The delay could be six months to a year, or longer-if the subcommittee ever completes itswork at all. At press-time, the group was preparing to ask the FCC to hold off any action on theissue of multichannel TVsounduntil new testscouldbe completed. But theFCCstaffhadalready prepareda proposal for issuance by the Commission to permit TV stations to chooseanystereosoundsystemwhichwould meet certaincriter ia-aso-called " marketplace"decision similar to the one that permittedany of a number of AM stereo systems, all mutuallyincompatible, to be broadcast simultaneously. (The AM stereoorder resultedin such confu-sionthat fewstationsbotheredtoaddstereo, andset manufacturersheldoff makingAMstereo receivers .) TV broadcasters and set makers are concerned that the FCC will issue itsproposal for "marketplace" stereoTVstandards(meaningnostandard) beforethesub-committee can complete itsnewtests. If such anorder isproposed by the FCC, thesubcommitteewill bedissolved, inviewof legal opinions that it wouldbeunlawful forrepresentativesof competingsystems tomeet while theFCCis considering theissue. Nomatter what happens, it now appears there will be a long delay, and if you want to hear stereosoundwithyourTVyou'll havetotunetoaPBS simulcast or go toJapanorGermany.The first major home banking and information system has been inaugurated commercially byChemical BankintheNewYorkCity area aftera 1a-monthtest in 200homes. Chemical'sPronto systemuses any home computer, a telephonemodem, automatic phone dialer,andspecial programcartridge; theBankwill supplytheentirereceivingsystem(except the TVset), basedonan Atsr!400 computer, ataround$500, but other homecomputers canbeused.Pronto customers, who pay a monthly fee of about $10, are able to call up bank statementson their TVscreens, transfer fundsamongdifferent Chemical Bankaccounts, paybillsbyelectronic fund transfer, and send electronic mail messages to other Pronto subscribers. Thesystem plugs into a modular telephone jack and is connectedto the bank's Tandemcompu-ter. Futureservices tobe offeredon theProntosysteminclude financial servicessuchasportfoliomanagement, teleshopping, educational courses , homebudgeting, andsecuritymonitoring. Chemical hopesthat its systemwill becomenationwide, andhasalreadypre-sentedseminars to250otherbanksandinstitutions.Thebanksaidthat morethan250major companiesalreadyareacceptingelectronicbill-payment viaPronto-including AmericanExpress, MasterCharge, Visa, major oil com-panies, most department stores, Sears, utilities, insurancecompanies, and major New Yorklandlords. In paying bills, Pronto users can specify regular monthly payments,and even whichdayof themonththeywishbillstobepaid. Privacyis assuredby a triple-security systemincludinghouseholdandpersonal 10 numbers , aswell asanindividual password. Bankofficials predicted that 10 million Americanhouseholds will have interactive devices attachedto theirTVsetsby theendof thedecade . R-ENEW METEOROLOGICAL SATELLITETIROS-N(ATN) METEOROLOGICALSATELLITEisthef irst of aseries ofadvancedTIROS-N/NOAAmeteorol ogi cal satell itesthat is bei ngdesignedand built for the National Oceanic and At mospheric Admini stration (NOAA). Inaddition to its usual weather-charti ng dut ies, the satell ite will be used to relaydistresscalls fromtheemergencybeaconsof downedairc raft andshipsindist ress . Launchisscheduled for Februar y 1983. NASA wi ll act as programmanagerfor themission.C/)ozog:oiu_ JLlIUis.;(c;r.;6" Fat her ofTelevision"is deadat age93Vladimir KosmaZworyki ndiedthis past July 29, at thePrinceton(NJ) Medical Center, just one dayshort of his93rdbirthday. Called" The Fath er of Te levision" bymany, he always declined the hon-or, pointing out that hundreds hadcontributedtotheart over manyyears. Invention, hesaid, islikebuilding a ladder, and that as eachengineer added a rung, " It enabledtheothers toclimbalitterhigherandseethenext problemalittlebetter."Thedevelopment of moderntelevision, however, isbasedonZworykin'ssteady workfromthe1920'sonward, especiallyhisin-vention of the iconoscope, the firstpractical camera tube.Dr. Zworykin wasborn July 30,1889, in Mourom, Russia. Heattended the Petrograd Institute ofTechnology, receiving an Electric-al Engineering degreein 1912. Atthe Institute he studied under Pro-fessorBorisRosing, and washislabassistant. Rosingbelievedasearly as 1908 that the cathode-raytube wasthesolutiontopracticaltelevision. Dr. Zworyki n, who cred-its bothhisdecision tobecomeascientist and his special interest intel evi sion toBoris Rosing's in-fluence, followedthat lineof rea-soninginhisworkontheicono-scope and kinescope.WHAT'Dr. Zwo ryki nj oined RCAin1929, servingas Director of theRCA Electronic Research Labora-tory in Camden, NJ until 1942, andafterwardat Princeton, until hisretirement in1954.Besides television Dr. Zworykinwas interested in a wide variety ofsubjects, ranging fromgunnerycontrols through multiplier tubes toelec t ron ica l ly co nt rolle d auto-mobiles. For a number of years af-ter his retirement, he directed theMedical ElectronicsCenter at theRockefellerInstituteinNew York,work ingfor thedevelopment ofelectronics methodsinmedicineand the life sciences.Zworykin received his doctoratefrom the University of Pittsburgh in1926. In 1966, President Johnsonawarded himtheUnitedStates'highest honor, the National Medalof Science, "for major contribu-tions to the instruments of scienceand television, and for stimulationof the application of engineering tomedicine." Altogether, he received27majorawardsandmuchotherrecognitionfromgroupsthrough-out the world.Aircraft entertainmentcarriedbyinfraredA wi reless-ente rta inment sys-tem using infrared light to carry thesignal isbeingdevelopedbythemicroelectroni c systems divisionNEWSof HughesAircraft Co. ThenewsystemisknownasAIRES(Ad-vanced Infra-Red EntertainmentSystem). Itusesadigital systemtransmittedthroughout theplanebyinfraredrays. The signal isre-ceived and decoded by a headsetworn by the passenger.AIREScantransmit upto 16channels. Eachheadset has aprogram-select and a volume con-trol. Aself-test feature assures thateac hunit remai ns inope ratingcondition.Theuseof infraredcuts theweight of thefull systemtolessthan half that of aconventionalentertai nment syste m, andthecost byone-third. Another greatadva ntage of th e infr a r edapproachisthat-unli keearlierwireless-entertainment systems-AIRES will not interfere with otheraircraft equipment. It isexpectedthat the new system will be on themarket by the middle of1983.KEYFAX, SSS SystemsplanteletextmagazineKEYFAXElectronicPublishingand SatelliteSyndicatedSystemshaveannou ncedthat KEYFAXNational Teletext Magazine will beready for delivery to cable house-holds shortly. This is stated tobethefirst large-scaleteletext con-sumer opera tionin theUni t edStates , and is expected by itsfounders to grow to 200,000 cablehouseholds within 30months.Thenew teletext magazine willbe delivered via the vertical blank-ing interval (VBI) of the WTBS sat-ellite service, which is available tomore than 20 million cable house-holds.Theservicewill beofferedtosubscribers at a suggested $19.90per month. Thatcovers$9.95 forthe service itself and $9.95 for rentof thenecessarydecoder. Oper-ators will retain$3.95 per month asrevenue ($4.95 after penetration to1percent of theirsystem'sbasicsubscribers).KEYFAX has been on the VBI ofWFLD-TVinChicagosinceApril1981, on a test basis.It hasalsobeen on the VBI of the WTBS sat-ellite service since May 1982, andwas displayed (viasatelliteandthenthroughtwoTVstations) atthe Knoxville World's Fair.N.J. StatePoliceImprove their radarsThe State Police of New Jerseyhave rece nt ly publicizedt heiracquisitionof "beam-interrupter"swi tc hes for thei r radar units.Those switches, when fitted to thedevices , permit cutt ing off theradar beam without turning off theequipment. When a car suspectedof speedingissighted,thebeamcanbeturnedoninstantly. If hehas a radar detector, the speederis not warned until police actuallystart taking a reading.Manufact ure rs of radar de-tectors state that such a device isonly minimally effective: "Once theofficer activates the unit to obtai n aspeed reading on a vehicle, everydetector-equippedmotorist withinitsrangewill receiveawarning.... The beam will alert all detector -equippedvehicleswithinseveralmiles."The State Police believe that, inspiteofany claimeddeficiencies,thebeaminterruptersareeffec-tive, and point out as evidence ofthat effect ivenessthat manufactur-ers have begun to install the beaminterrupters onnewradars as astandard equipment.Videoprograms aidtechnical trainingRCA'sCorporateEngineeringEducati on(CEE) unit at CherryHill, NJ, reports that acompany-wide programof video courses hassimplifiedtheproblem of keepingengineers, managers, andothertechnical personnel at RCAup todate onth every lat est tec h-nological advances.Thecompanyhasrecentlybe-guntoaugment thevideo pro-grams withlivecoursesonsub-jects requiring extensive hands-onexercises andcoursesfor smallgroup projects.Most video courses consist of 12two-hoursessions, conductedasdiscussions , exe rc ises , andhands-onactivities supervisedbyan associate instructor.In addition to the more than70video courses listed in CEE's cata-log, CEEmaintains alibraryofvideotapesof technical seminarsand talks; the library is maintainedso that the tapes can be borrowedand viewedbyRCApersonnel attheirconvenience. R-ETEK 2200MULTI-PURPOSEOSCILLOSCOPESTHE PERFORMANCEIPRI CESTANDARDNow! A60 MHz Tektronix scopebuilt for your bench.In 30 years of Tektronix oscil-loscope leadership, no otherscopes have recorded theimmediate popular appeal ofthe Tek 2200 Series. The Tek2213and 2215 are unapproachable for theperformance andreliability theyoffer at a surprisingly affordableprice.There's no compromise withTektroni x quality: The low costis theresult of a new design concept thatcut mechanical partsby 65%. Cutcablingby 90%. Virtually eliminatedboardelectri ca l connectors. Andobviated the usual cooling fan.' Price FOB. Beaverton, OR. Price subject to change .Copynght @1982Tektronix, Inc . All rights reserved. 135-1Yet perf ormance is written alloverthe front panels. There's the band-width for digital and analog circuits.The sensitivity for low signal mea-surement s. The sweep speeds forfast logic famil ies. Anddelayedsweep for fast, accurate timingmeasurements.The cost: $1200* for the 2213.$1450* for the dual timebase 2215.You can order, or obtain moreinformat ion, through the TektronixNational Marketing Center, wheretechnical personnelcan answeryour questionsand expeditedelivery. Your direct order includ esprob es, operating manuals, 15-day return policy and full Tektronixwarranty.For quantity purchases, pleasecontact your local Tektronix salesrepresentative.ORDER TOLL FREE1-800-426-2200Ask for Departmen t J0147In the state of Washington,Call (206) 253-5353 collect.l;()f.WATTUl TOEXCEllrEomom:s::OJm:D7(J)oZoa:I-oW-.JWoo-ca:8PUBLISHER'S LETTERThisDecemberissue of Radio-Electronicsmagazine brings theyear1982 to a close. It has been an exciting one. We delivered fourspecial sections during1982-"Video Electronics" in January, "YourOwnComputer"in April and again in October;plus a "VideoGames" sectionin July. Along the way we were able to publishmorethan150 articlescovering a varietyof subjects-audio, video, com-puters,radio, construction, how-to-toname just some of the variedareas we covered. We also logged a couple of exceptionalconstruc-tion stories-weshowedhow tobuild your own satellite TVreceiver;and a first forhome constructors: your own picture phone.In 1983 wepromise to bring you more of the same. The samequality, thesame wide range of subjectareas, the same first-rateelectronicsthat kept you readingRadio-Electronicsin record num-bers all the way through1982. We'veenlarged our staff, we'veaddedmore pagesto themagazine,and we'veadded a sisterpublication, Special Projects, that is specially designed to cater tothe needs of theproject builder.However, there are some things we won'tdo. We will notbecomea computermagazine; we will not becomea video-gamesmagazine,and we will not dive into and followblindly every one of thepaths inelectronicsthatis bound to developduring1983. Wewill remain thebroad-based, all-encompassingelectronicsmagazine that we havebeen for the past53 years. Each year welearn a little more, and-thatmakes us better.One bit of badnews, however-subscriptionprices are going upstartingin January1983. Theyare going up an average of $2.00 peryear.So if you want to save yourself a few dollars, use thesubscription-order form in thisissue-it'sinside the back cover.Nextmonth the prices on that card will be higher.I'd like to thankyou for your continuedsupport and pledge that wewill continueto do our very best to make Radio-Electronics the fin-est "electronics" magazine youread.~ / k p L'''''t/ Y (;If LARRYSTECKLERPUBLISHERladia-EleclriinicilHugoGernsback(1884-1967) founderM. Harvey Gernsback, editor-in-chiefLarrySteckler, CET, publisherArthurKleiman, editorJosef Bernard, K2HUF, technical editorCarl Laron , WB2SLR, assistant editorJack Darr, CET, service editorRobertF. Scott, semiconductor editorHerbFriedman,communications editorGaryH. Arlen, contributing editorDavidLachenbruch,contributing editorEarl "Doc" Savage, K4SDS, hobby editorDanRosenbloom, production managerRobert A. W. Lowndes, productionassociateStefanie A.Mas,production assistantJoanRoman, circulation directorArlineR. Fishman,advertising coordinatorCover photo byRobert LewisRadio-Electronics is indexed inAppliedSci-ence & Technology Index andReadersGuide to Periodical Literature.GernsbackPublications , Inc.200Park Ave. S" NewYork, NY10003President:M, Harvey GernsbackVicePresident; LarryStecklerADVERTISINGSALES212-7776400LarryStecklerPublisherEASTStanley LevitanRadio-Electronics200Park Ave, SouthNew York, NY10003212-777-6400MIDWESTlTexas/Arkansas/Okla.RalphBergenThe RalphBergenCo.,Inc,540FrontageRoad-Suite 325Northfield, Illinois 60093312-446-1444PACIFICCOASTMountainStatesMarvinGreenRadio-Electronics413 So. LaBrea Ave,Los Angeles, Ca 90036213-938-0166-7SOUTHEASTPaul McGinnisPaul McGinnis Company60East 42ndStreetNew York, N,Y, 10017212-490-1021~~A FREE 9100 Electronic Soldering System when you buyeither desoldering system by December 15,1982.. .. .. A solid-state control adjusts tiptem-perature from 500to 1000F. Theloadmodulated heater assuresinstanta-neous recovery andsuppressionoftransient spikes.Theswitch that activates thehigh-flow vacuumis convenientlybuilt intoa handle that is biomechanically de-signedto reducefat igue andincreaseproductivity.Comes complete with : LongLifeTips#2005, #2006, # 2007, # 2008;TipCleaning Tool # 2002; Free-StandingHolder #8800 withKleen-TipSponge; and Tray #400.Pack of 10 Filters , #2039.Contact your nearest authorized Ungardealer or call theUngar Hotline,toll -free 1-800-421-1538, in California,call collect, 1-213-774-5950.Offer gooduntil December 15,1982.Ungar's newest electronic solderingsystem. Electronic, closed-loopvariable control permits temperatureadjustment from 400to800F.Therrno-Durice heater deliversheat totipandawayfromeasy-to-holdMicro-Size handle.Includes neon"on/off"light , right -or left-hand mount andflexible, heat -resistant cord.Comes complete with : baseunitwithbuilt-in controller, handle, 1/16"screwdriver, tip#9012, sponge andtiptray, sponge andiron holder.Take thisruggedly constructed, light-weight unit anywhere-plugs intoany120V outlet.Solid-state control ad-juststiptemperature from500to1000F and suppresses transient spikes.High-flow vacuum is activated by aswitchmounted ina handle that'sbiomechanically designed to reducefatigueandincrease productivity.Super quiet andvirtually main-tenance-free, withUngar'sexclusivelow-noise exhaust and unique vibration-absorbing pump mounting.Allbuiltinto a galvanizedsteel casewithascratch-resistant , bakedenamel finish.Comes complete with: LongLifeTips#2005, #2006, #2007, #2008;TipCleaning Tool #2002;Kleen-TipSponge and Tray#400; andPack of10 Filters #2039.CIRCLE9 ONFREE INFORMATIONCARDSATELLITE/TELETEXT NEWSGARY ARLENCONTRIBUTINGEDITORSATELLITEThe FCC has adopted a new procedurefor accepting applications for satell ite orbital slots,APPLICATIONStailored foruse with the pendingproposal to push the slots closer together . The new plan,which probably will give preference to the 10 companies that have already filed applications,calls for proposals submitted by mid-May to be considered first in any processing procedure.After thoseprojectshavebeenactedupon, theFCC will considernewapplications. Theaction reduces the likelihood that the FCCwill conduct competitive hearings if two companiesseek thesame orbital slot.MOREThere'smore competi tion than ever forsatellite space-andsomeof themajorcomputerSATELLITEcompanies are now joining the fray. For example, Satellite Busi ness Systems-the partner-ship ofIBM, Comsat General, and Aetnainsurance-is settingup a newmedium-to high-DATAspeed Data NetworkService, designed for custo merswithlower-volumedata com-SERVICESmunicationsrequirements. Inaseparatedevelopment, AmericanSatelliteCompanyandTandem Computers Inc. are jointly developing the world's first computer networkwith full-integratedsatellitetransmission. TheASC-Tandemproject, calledInfosat, will offer con-tinuous online transact ion processing, distributed data processing, and information systemsmanagement.AROUND THELegal actiononmanyfronts involvingsatellitereception: satellitemaster antennaTVSATELLITEoperatorsinseveral cities aresuingprogramsupplierssuch asShowt ime, The MovieChannel, and others, for failing to deal with them to carry shows; in some cases the SMATVCIRCUIToperators contend that pressure from local cable systems has prompted the retrenchment byprogrammers. Meanwhi le, in a case that could set a precedentfor satellite-TVreception, afederal court inWashingtoncamedown hardonalocal dealer whosoldunauthorizedreceiversdeisgnedtopickupHBOshowsonmultipoint distributionservice microwavechannels. The court awarded more than $102,000 in damages to Marquee TV Network, thelocal MDS-HBO service, resulting from the "i llegal conduct" of a small local company whichadvertised, sold, andinstalledMDSreceivers;theawardwasthehighest amount evergranted in a pay-TV piracy case,and represented reimbursement of fundswhich Marqueeclaimed it lost because of the unauthorized devices, which could pick up its HBO signal. Thecourt also granted permanent injunctionsagainst several other companiesthat sold similarreception equipment.WORLDWIDECable News Network may become an internat ional service, transmitted via Intelsat, if CNN'sCNNTed Turner has his way. Turner is negot iating withComsat for access to the Intelsat system sothat CNN can be sent to South America, Africa, Europe, and Asia. CNN has already signed adeal with a Japanese cable TV company to carry CNN in Japan 17 hours per day as soon as!an overseastransponderleaseis completed . In return, CNNwill beginpickingup a dailyround-up of Japanese businessnews, fedby satellite fromTokyo.II"DISHImagine a little red wagon-the kind kids play with-equipped with a four-foot satellite dish, a~STRETCHER"12-volt battery for power, 1000LNA, and a satellite receiver. Tulsa-based AutomationTech-!niques Inc. called this portable set-up "Toysat"-and used the micro-miniature arrangementto emphasize the potential value of its new electronic "Dish Stretcher ." That unit is intended toerase"sparklies" aswell astheother kindsof interferencethat oftenafflict small-dish(f) receiversystems .0Accordingto ATI, the level of sparklies or impulse noise in a satell ite picturehas been aZ0function of either the size and efficiency of the antenna, noise figure of theLNNreceiver, ora:the carrier-to-noisethresholdof thereceiver. ATI attacked thesparklie problemin a fourthI-0area of the receiver system: detectedvideo signal. The sparkliesgeneratedbecause of theui--lsmaller dish are identifiedby Dish Stretchertechnologyas impropervideoinformation andui6are removed from the picture signal after entering the receiver. The $500 unit is availablefromCi ATI, 1846N. 106thE. Ave. , Tulsa, OK 74116. R-Ea:10----THE POMONA PROMISEWe provide the design engineer with the best"black boxes" made in this country.Or anywhere.That mayseem likeatoughpromise todeliver on. But if youtalktothe professionals of theelectronics industry, you'll learnquickly and with great assurancethat the "blackboxes" designedandproducedby ITTPomonaElectronics arelookeduponasthe best in the business. Bar none.Thereasongoes backtowhen we first introduced the ideaof providingconvenient con-tainers for special test circuits. Wepromised then that ours would bethebest. Andthat'sthe wayit'sbeen.Sincethenourline has ex-panded toelevendifferentseriesto accommodate just about anycomponent packaging require-ment you'll ever need.AtITTPomona Electronics,we know there is no such thing asstandingpat. We alsoknowthatyour needs changeandyour ex-pectations becomegreateras thedemands become more severe. Tothis end we will continue to createa better way. A better product.That's a promise.All of our products aredescribedandillustratedin ourGeneral Catalog, and it'sfree. Justcall (714) 623-3463or 623-6751.CIRCLE 8 ON FREE INFORMATION CARDTWX 910-581-3822. Write to usatITTPomonaElectronics, aDivi-sionof International TelephoneandTelegraphCorporation, 1500E. Ninth St., Pomona, CA 91766.InEurope: ITTCANNONBELGIUMS.A.lN.V. Rue ColonelBourg Str. 105 Space A (B.3) 1140Brussels, Belgium. Phone:02-735-6094.Our productsare availablethrough your favorite electronicsparts distributor.ITTPomonaElectronicsomoms:OJmJJ11ePHILIPSKElT HLEYNon-Linear Systerna15 MHzTRIGGEREDSWEEP SCOPE.":D - Mode automatically shifts between8 CHOPandALTERNATErn _ Bright P31bluephosphorzSl- Front-panel X-V operation - Differential Input capability - 19 calibratedsweeps-.5JLSEC/cmil to.5SEC/cm - Sweep to.1JLSEC/cm with5x;en 1.5SEC/cm withuncallbrated vernierMODEL14775" SCOPES." - Triggeredand automatic sweepg- 18 calibratedsweepsrn _ On 1476 modeautomatically shifts betweenCHOP andALTERNATE.... . - Bright P31bluephosphor - Front panel X-V operationusing matchedvertical ampsg-Videosync separatorsmen _ Check most digital logic circuitry --,' C;:1466

TRACE$32995WAS $48000Special offer to readers ofRadio-Electronics. AdvanceElectronics has madethe larg-est oscilloscopepurchaseinour history and wearepassingthesavings on toyouourcustomers. The prices shownareavailableas long asquantities last. Pleasecall ear-lyas thesepriceswill not behad again.- TrueRMS- Analogdisplay- Peak holdNTSCCOLOR-BARGENERATOR- GeneratesNTSCcolor barswithor wlthout-IWQ signal- Generates 5 steplinearstaircase; staircase withhigh orlowchroma- External videoInput-modulates rf orIf carrier outputs- Crystal controlledrf, I-f, NTSC syncProfessionalstudio quality generator. Ultra stable. Ideal forVTR work.DIGITALMULTIMETER$16995MODEL420 Reg. $19400- Sine,squareand triangleoutput- Variableand fixedTTLoutputsrc-'I FUNCTIONGENERATOR----'-MODEL1650 FuncUons asthreeseparate suppl -los Exclusivetricking circuit Axedoutput 5VDC, SA Two 0 to 25VDCoutputl at O.SA FUllyautCKMtl c, current-li mitedovenoedprotectionPOWERSUPPLIES$29995was $375:1 and the betaof Q2is132, the current and power gainsof the overall circuit are131 X 132' But thevoltage gain sti ll remai ns slightly lessthanI , as it didfor the emitter follower.TheinputimpedanceisRE multipliedbytheproduct of thebetas, inparallelwithRB. The valueof RB can bequitelarge in that circuit as there is only a smallamount of basecurre nt inQI .That QIbasecurrentmust equal (Vcc - 2VBE)/(f31 f3 2RE +RB) for a substantial amountof emitter current toflowin Q2.The output impedance of that circuit isRB/f3,f32 in parallel with RE. ThevaluescontinuedOil page1028 VISA 0 MASTERCARD (IUnkNo Iom()ms::tllm:IJTo Order FromConnectic ut OrFor Tech. Assist. Call (203) 354-9375NETRONICS R&D LTD. Dept.333 LitchfieldRoad, NewMilford, CT 06776Please sendtheitemschecked below:Cont inent al U,S.A. Credit CardBuyersOut side Connectic utCALLTOLLFREE 8002437428ANNOUNCING TWONEW TERMINALSTotal EncIosed$ ---=--=-----,--,---,-----;::-.,--,----:-c:-:------=:---:--oPersonal Chec k 0 Cashier 'sCheck/Mon ey OrderoVISA 0 MasterCard (Bank No, _Acct. No. Exp, Date _SignaturePrint Name _Address _City St ate ZipFor Canadianorders, doublet hepostage . Conn. res, addsalesl ax.Net roni csannou ncesastal e of the artbreakthro ughin t e rm i nal s. nowa t pr ic e s yo ucanafford, you can go en-line withdata -bankandcomputerphone-line servic es. It 's allyours: " el ect ronicnewspaper s." e d uca tionalservic es. Dow-Jones stoc kreport s. game s,recip es. pers onal computi ngwithanylevella ng u a g e , programexcha nges , electroni cbul-leti nboard s . , . andmoreevery day ! ! !Netronl cs off erstwonewtermi nal s. bot h featureafu ll 56key/ 128 charactertypewrit er-s ty le keyboard , baud rates to 19 .2kilo b a ud . arugoedsteel cabinet andpower supply. Thes im p le s t one,isa16 li neby 6.4 or32 charact erperli ne unit. with a serialprin ter port for makinghardcopyof all incomingdata . andoptional provi sionsfor block andspecial character graphic s. The "s mart" version,SMAAT EAM-80, features either 24line by 80charact ersper lineor16 by40 character sper line . it offer s on-scr eenedi ti ng wi t hpaQeat ati meprin ting, 12,000pi xel graphi cs. linegrap hi cs, abso lutecurso raddres si ng, underl tolng, del uxgreenphosphor monit or picturedabove.ForhardcopyJust addour mat chedprinter.Pri cebreakthrough!!! Ownth e FASTEAM64, a co mpleteterminal ki t. readytoplugintorj ust $199.95 or order theSMAATERM80 kit tor j ust $299.95. (bot havailabl e wiredandtested.)Be on-tinewith themill ion-dolla r computersanddataservicestoday . ..we evensupplythenece ssarysubscriptionforms.Moregoodnews: All thecomponents inour terminalsareavai lable separat ely (seecoupon), soyoubuy onlywhat you need! ! !FASTERMS4 . , . DISPLAYFORMAT : 64 or 32 charact ersfli neby16 lines . , 96 displayableASCII characters(upper &lower easel . . . 8 baudrate s:150, 300,600, 1200. 2"f"ll for afully expandedEx- S'gn.llun" _ klllSV ff'df'luxr stf"f"1 Prtnt Name _r...binel ... $39.11S plus 52 PAl. "NEEDAT ERMI NAL '! WI"offer youchoices Ihe 1f";&51expe nsive o neII o u r He x: ' kil .lhal diS' pla ys Ih eInfo r mahon ona \ ca lc ula lor.ty pe se ref"n . Th f" ot he r c hOice i s o u r ASCII: Research&DevelopmentLtd.1.................................... ..... ... .... .....,ONLY $129.95 Learn Computing ::From The Ground Up , ._ :: BuildaComputer kit that grows 1- :: withyou, andcanexpandto64k v :: RAM, Microsoft BASIC, Text Edi " .:: tor/Assembl er ,\\Ord Processor,: Flopp y Disks and mor e. :EXp 'ORER/8S . , PI", on "","" E h..n-:,.,. :L.; I"I-r'"Ml CIOIO!l BASICIIr .J PluJC in Nf'lrnnw' .. 111')( Ed.!nr/A... ..... mli' ..r rn UO'-t Kf')TXKl1Dr'f!/u.... i1d! WfI SWOhOllnl.. :2"' ddBIIIIII h """ yr. , own ru..ll lOl rtr- !'ilnn 1"1111.. (pmln l yp ill.lt Iln'l'I' ;) Add 04 kH.r\\1 r. ( ,huw,," h'rmill/I' ------------ :a CRTmonitor ora 1V se t ( If }IOU have an RF modu lator) :o He xki f 169.95 plus S2 par I .oFASTERM- 604TERMINALKIT - featUringa ssk"", :ASC II Keyboard.128 character setupp erand lowercase , I15 ohmoutput . 8baud rates 150to 19 200 (switchserect -able ).RS2321C or20 M....o utput . 32 or &4 charac te r by16linelorma ts. ccmcrete wnn Delu xe Steel Cabmet and . - -Power Supply .. . . $199.95plus S3 PAl.79COMPUTERCORNERSelectingan accountingpackageLESSPINDLE*enozoa:~oW...JW6oa:80OFFICE AUTOMATIONPERFORMS AVARI-etyof useful functions that cangreat lyincrease the cost -effectiveness of eachemployee. In previous columns, we haveexamined such sophisticated business -software innovations as database man-agement systems(DBMS) and financial-planning programs (like VisiCalc). Thosestate-of-the-art programs offer creativesolutions toeveryday office problems.Perhaps less ostentatious-but no lessuseful-are the software packagesavail-able for everyday bookkeeping tasks, oneofwhichis showninFig. 1.FIG. 1General ledger , accounts payable,accounts receivable, inve ntory, andpayroll form what are commonly referredto as the" Big 5"accounting programs.The bookkeeper who workswith qualityprogramsin each of those categories--oroptsfora complete interactive " Big 5"package-will benefit fromgreatly in-creasedproductivity from his accountingstaff.Careful pl anni ng an d se lec t iveshopping-as always-arethe keys tofindi ng the software that will be bestsuited to your purposes . It is important toselect software that. offers enough fea-tures and optionsto make the conversionof your bookkeepi ngrecords relativelysimple. At thesame time, it iswisetose lect packages th at alloweno ug hflexibilityfor youtofine-tunethepro-gramtoyourownspecia l requirements .Let's take a look at a few criteria to keepin mind when choosing variousaccount -ing programsforyouroffice .In planning to computerize yourgeneral-ledger system, begin by definingyourneeds. Can that system operatein-" Manaqinq Editor, Interface Agemagazinedependently, or isit preferabletohaveone that interacts with other " Big-S" pro-grams? Will it be restricted to the finan-cialactivitiesofoneoffice, ormustthereports fromvarious branch offices orsubsidiar ies beintegrated as well? Whatis the volume of transactions? It is impor-tant thatyour computer system havethememory capacity to support the necessaryfunctions. Howeducatedisyour officestaff in computerfunctions? That is im-portant inchoosingbetweenageneral-ledger packagethat uses astep-by-stepformat toguidethenoviceuserthroughthe program, or a more sophisticatedoffer ing.It is important to chart out all ofyourrequirements before evenbeginningtoshop. The salesmandemonstrating thesoftwarewill only be able to direct you tothe package best suited to your purposes ifhe has a good idea of the quantity of datathat has to be processed and the specificrequ ir ements of yo ur bookkeepingmethods.A general ledger is essentially a finan-cial history ofa specific accounting per-iod that lets management analyze a com-pany' s profiletodetermine appropriateplanningstrategies. The primaryfunc-tions are tokeeparecordof financialtransactionsandtheresultingbalances,and to generate regul ar balance- sheetsandprofit/loss statements.It is vital for a general-ledger programto use a double-entry accounting system.(That means that for every dollar of debit,thereisacorrespondingcreditentryofequalamount, andviceversa.) Double-entry bookkeeping is a safeguard to insurethat all account sareinbalance.Another point tolookforisthesys-tem' sabilitytosetupaproperchartofaccounts. That is a crucial part of thegeneral -ledger framework,for it can pro-vide rapiddepartme ntal profiles, as wellas a perspective on the financial status ofthe entire company. Since the allowablenumber of accounts varies from packageto package, the prospective buyer shouldselect a packagethat canhandle the cur-rentnumberofaccounts, and is flexibleenoughto expandas the company does.Accountspayable/receivableAn acco unts-paya ble or -receivablepackage has five primaryfunctions. Itmust: create master files for customersand vendors; record sales and purchases;index all sales/purchase data with theappropriatemaster files; manipul atethedata, and prepare summary reports bymaster file account, date, or some otherreference.As with general-ledger programs, yourparticular needs will determine the appro-priatechecklist ofrequiredfeatures thatyou shouldprepare.One ofthe important criteria is the abil-ity to produce audit trails---especially forcompanies that require a certified audit. Agood program will automatically preparea transaction listing immediately after thedata isinput.Most accounts-payable systems willrequire more deta iled record -keeping.For example, acheck mayhavetobecoded to multiple accounts (for example,when a single check pays a bill that coversdifferent accounts) .Job-costingisanother important fea-ture, as many manufacturers will need toaccess accumulated costs byj ob. Anaccounts-payable system set up to handlejob-costing canaccept jobcodes as wellas account numbers.Amongother itemstokeepinmindare: commission accounting (some com-panie s don't pay commissions to thesalesman until after the company is paid)and financecharges. Thebetter account-ing packages are able tocompute andassignfinancechargesrapidlyandeffi-ciently. Most accounts-receivable sys-temswillprintstatementsand invoices,andgoodones will automaticallyprintchecks- bothfunctions are useful andtime-saving fortheaccountant.Inventory controlThere are several benefits in managingthe flowof merchandise to be gained froman invent ory-control program. Over-stocks canbereducedandout-of-stocksituationscanbeavoided. Theaveragesmall business pays 25- 50% of the valueof its inventory just in inventory carrying-costs.The twomost common approaches toautomating inventory control are invoic-ingand order entry. Withtheinvoicingapproach, theprogramwon' t acceptin-voici ng dat a unt il after the order isfilled-generatinganinvoiceonly uponcompletion of the order. That system hasthe drawbackof not beingabletolistnow. If not fully satisfied whenyou receive your first copy ofPC, simply return your mailinglabel within15 days for a fullrefund.Thisislhemagazinethat tells youall about it.IBMAnnouncesCPLM-86Stat e Zipo12 issues/ $27.00 0 24 issues/ $46.00oVISA 0 MasterCard 0 Bill meexpires _oI am thinking about buying onePhone Credit CardOrders to:(Toll Free Number)California: 800/792-0990. ext. 1136All Other States: 800/ 227-3800. ext. 1136WOrdSfarReleasedBaby Blue, V.in-Dafa Files,F O R ~ HHundreds of New'!2.oduc!s ~ '.,_t N......... ): :oI already own an IBM " PC"Dept.RE10,PC Magazine1528 Irving St. ,S.F., CA 94122NameCity _o6 issues/$14.50oCheck enclosedCard # '--'--'--'--'--'--'--'--'--'--'--'--'--'--'---'RE12L JComputer clubs, events andpublications.For a limited time, you cansubscribetoPC at NO RISKandstill receive a 25%discountoffthe newsstandprice. Enter your subscription.. --. .. -- iii i i:.. ~r--------------------------: j : :: : :- - - - - - - - - - - - - - - - - - - ~Address _InterestedintheIBMPersDnalComputer?f you're interested inthe IBMPersonalComputerthen youneedPC magazine.PC magazineis theIndependent GuidetoIBMPersonal Computers. Eachissue is packed withinformationforeveryoneinterestedin IBMPersonalComputers.PC magazine tells you howtoput togetherthe best IBM"PC" system and then how toget the most out of it. Eachissue brings you hundreds ofcolorful pages of evaluations,insights, and straight talk fromrespectedexperts-professionalsin computerscience as well as writers,businessmen, lawyers,educators, andmany others.PC coverssoftware,hardware, applications andmost every topicofimportance tothethousandsof IBMPersonal Computerusers whoreadit. To ensurethat we give youtheinformation youneed, PCincludes a special "User-to-User" section, as well as a"PC Wish List", andnewsabout IBMPersonalCIRCLE17 ON FREE INFORMATION CARDCIRCLE94ONFREEINFORMATIONCARDBEAUTIFULELECTRONICCABINETSRIIOADE ' I FABTRON Diy., P.O. Box 925Col umbi a. TN 38401NATIONALCORPORATION Phone: (615) 3811143utelabor coststotheproper files, andcompile the information required for gov-ernmentreports.The most commonfeatures onecanexp ect in a package are : computingFICA, stateunempl oyment , andfederalandstate taxes; reportingof employeeearn i ngs by cate gory (s uch as de-partment); generatingquarterlyandan-nual government tax filings; and handlingof miscella neo us items (non-taxableitems, overtime pay, savingsand dentalplans.)There are a myriad of other features tobe found in various accounting packages.Among them are: reports on hours work-edaswellasdollaramounts bydepart-ment and job; union reports; earnings his-toryfor eachemployee; employeefiles(hire, review, and termination dates), anddata onearned-incomecredits.Morethananyother accountingpro-gram, agoodpayroll programcansaveweeksofemployeelaborper year. Butbecause of the confide ntiality, timeli-ness, and accuracy required, choosing therightoneisan especially crucial step inputting t ogether a co mputeri ze dbookkeepin g system.Samplethebrochures from many dif-ferent vendors and ask as many questionsas you have to to satisfy yourself beforedecidingwhich package has the featuresthat will workbest inyour accountingorganization. R-EPayrollA payroll system is set up primarily tocomput e and print payroll checks, distrib-backorders and open-orders.An order-entry system will accept thedat a at an y time, sepa rat ing orde r-placementandinvoicing into two differ-ent steps . Also, open-or ders may bealteredinanywaycalledfor , prior tobilling. Most businesses will benefit fromthat approach, as opposedtothe morelimit inginvoicingsetup.An obvious , but critical, considerationintheselectionprocessisknowingthesystem's ability to handle the currentvolume of items-as well as knowing itscapability for coping with future growth.That ofteninvolves hardwaredecisionssuch as whether your disk capacity is suf-ficient to handle the data involved. Mostinventory packages on the market willhandle at least 1000 items of stock, whichshouldbe adequateformost smallbusi-nesses.The allowable size of data fields is alsoveryimportant. Basicspecificationsforitems in stock must be supplement ed withother information. Make sure that thepackage you select allows for that. Suchdataas product classor code, averagecost, previous cost, and product descrip-tion are often required, so your data fieldsmust be structuredwith enoughspace toenter thenecessaryinformation .Sturdy ExtrudedAlumi numFront & Rear.050 Black Wrinkl eAl uminumTop &BollomRemovabl e ClearPlast icPanel sStoc kNo. Insi de Dimensions PriceEA2020805 1'h " H x 81I8'OWx 5118" D $18.54EA2021209l'h " Hx 12" W x 9" D $24.90EA3 0308052 'h " H x 8-1/8" Wx 5118" D $22.27EA30312092 'h " H x12" Wx 9" D $30.97TOORDER: Enclose Check, MasterCardor VISANo. Add$3.00 Ship ping &Handling.Contact theFactor yforQuantit ypr icing , customenclosures,andourfuli li ne catalog. Dist ri but orsand O.E.M.inquiri es welc ome.

CUSTOM & STOCKA.W.SPERRYINSTRUMENTSINC.TheMeasurable Advantage."SeeUs At Midcon'82- Booth#620" CIRCLE93 ON FREEINFORMATIONCARD"At ABC's Wide World of Sports wedon'tplaygames. We use the AWS Digisnap:"William Stone."A k ABC' Wid W ld f 0 d ' f . 1d Technical Manager, ABC-TVS everyone nows, s 1 e or 0 utstan mgeatures meu e:Sports does thejob of coverin9 Autoranging. For more information on the Digisnapevents for television, The explc;:Inahon1S sim- Large, digit LCD. Model DSA-lOOO. or any oftheotherfinefor totalp.erfechon. Cameras, 75,000 hour/rated rechargeable battery AWS instruments, call your distributorlightmg a.nd sound equipment must always life. today or contact A. W. Sperry Ins trumentsbt;! operatmg at performance. All elec- Up to 75 hours continued use between Inc . P.O. Box 9300. Smithtown. N.Y. 11787tncalandelectron ichook-upsa rechecked charges 800-645-5398 Toll-Free (N.Y. , Hawaii.andre -checked. And if a problemshould P kdt' t t& Alaskacallcollect516-231-7050).occur, it must be found and corrected _ fas t. ea e ec or measures currenThat's why ABC technicians rely on the AWS voltage surges. .Digisnap digital snap-around volt -ohm- Overloadon a.ll ranges.ammeter for theirelectrical testingneeds. Teor-drop Jaw design forIts autoranging feature saves them valuable workmg m hght areas.time and its readings are consistantly Electronic data lock to freeze reading.reliable and accurate." Housed inshock-resistant ABSplastic.omom:!:OJm:0Call Toll Free800-227-9754in Californiacall collect415-941-6942PhoneCompany450 First Street (Box 689)LosAltos, CA94022TouchToneisaregistered trodemar1< ofAT&I -.WihingThePerfectExtensionPhoneWith theVIKINGIIyoucan nowhaveanextensionphoneright atyoursidewhereveryou may beinoraround your house.Simply take itwith youasyoumove from placetoplace andyour calls willcomeright toyou.No morerunning forthephone, nomorelong extension cords orextrajacks.And best of all, nomonthly rental charges from thephone company. For privacy, aspecialbuilt-in system ofsub-audibletones and theuse of multiplefre-quencies preventsany other partableunitsfrom gaining access toyour line.To orderjustsendcheck ormoney order for$1 49.95, plus$5.95shippingand handling, toVi king Phone Company.(Californiaresidentsadd6~ %sales tax.) Master ChargeorVISAcreditcard usersrnayarder byphone.JUST $14995Far less thancompetitive unitsthatdon't begin toequal VIKING IIperformanceTrueTouch-Tone DialingTheVIKING IIoperates withatrueTouch Tonekey-board...not thepushbutton pulse-dialersfoundonotherunits.This meansyou can use allthespecial telephoneservi cesavailabletoTouchTonephones, even if yourpresent phoneisaconven-tionalrotary dial model. Banking andbill paying byphoneandtheeconomical longdistance servicesof SPRINTand MCI arejust afewof theconven-ienceswhichcanbe yourswithyourVIKINGl1.Imaginebeing able tomake orreceive phone calls from an'yWhereyoumay be, inoraround your home.Inthekitchen,den, bedrooms orbath.And outside too! On thepatio, bythe pool, outinthe garden...orevenwalking your dog. An'yWhere and everywhereupto800feet - withnowires orlong extension cords...AND nomonthlyrentalcharges.The allnewVIKING IIhas been designed andengineeredinColifomia'sfamous"SiliconVall ey"tobring themostadvancedspace-age telephone capabilitiesright intoyour own home.And nowit can beyoursfora 15dayfree trial. Use it andsee foryourself.Ifyou arenotcompletely satisfied with itsremarkable perfor-mance,just send it backandreceive afullrefund of thelowpurchaseprice ofjust$149.95.So EasyTo UseThe VIKING IIlooks andworksjustlikethe most modemextension phones. Onlyit hasnocord at all!Irsanattractive, light-weight instrument that isverycomfortabletouse...and easy totake with you asyoumovefrom place toplace around your home.It comes complete withasmall contempararydesign Base Unit which yousimplyplug intoaphonejackandanyAC currentoutlet.Theremotecardless phone is"connected" totheBaseUnit bytwo channels of hi-fi FM radio, asauthorized bytheFCC. The portable handset operatesonbatteries,whichcan be rechargedwithitsownchargerat anyACoutlet. Unlike most cordl ess phones,theVIKI NG IIdoesnothave tobeplugged into theBase Unit forrecharging.And there isevenasmallred light toremind you when irstimetocharge.Compare ItWith OtherCordless PhonesThe VIKING IIeasily outperforms competitiveunits costing uptotwiceasmuch. Unlikemostcordless phonesonthemarket, it doesn't look orworklikeaCB"walkie-talkie:' TheVI KINGIIincor-poratesfull"duplex" operation, whichletsyoutalkand listenjustasyou dowith your regUlar phone.There are nobuttons topush totalk and there'sno"roger, over andour ' nonsense. It operatesloudandclear at distances upto800feet from itsBaseUnit...more thantwicetherangeof manyunits.And it comeswith alimitedwarranty...forafull 90days.The onlycordless extension phonewith true Touch tone, dialing thatworks anywhere inside or outsideyour home... up to 800 feet away.Introducing thefirstSfafe-ot=fhe-ArfCordless Phone~ i h i n g l lCIRCLE96 ON FREE INFORMATION CARD 83NEWIDEASLow-batteryindicatorTODAY MANY HOBBYISTS BUILDBATTERY-operated projects usi ng highl y efficientsolid-statedevices that ensure long battery-life . Even with those ci rcuits, though, aneed occasionally arises to make certain thatthebattery-whichmayhavebeeninusefor sometime-is still in good condition. Iuse the low-battery indicatorshown in Fig.I in several battery-powered special-effectsdevicesfor thetheater , whereit iscrucialthat eve rything operate when it' s supposedto.is selectedby the potentiometer; the devicecan be adjusted most easi ly by applying to itthevoltageatwhichyouwant theLEDtoturn on and adj usting the potentiometer untilit j ust does so.Theindicator usesonlysixparts: RI is27K; R2 is al OOK linear potentiometer; R3is 1K, andZenerdiodeDI isratedat6.2volts; IeI is a 741 , and ju st about any LEDwillwork . The deviceis easytobuildanddoesn't present much of a load to the batte ryit monit ors-theversionIusedrawsonlyNEWIDEASThis column is devotedto newideas,circuits, device appl icat ions. construc-tiontechniques, helpfu l hints , etc.All published entries. upon publica-t ion. will earn$25. Inaddit ion. Panavisewi ll donate their model 333-TheRapidAssemb lyCircuit Board Hol der. havingaretail priceof $39.95. Itfeatures an eight-position rotatingadjust ment . indexingat45-degree increments. and six positiveloc kpositions in thevert ical plane, givingyou afull ten- inch height adj ustment forcomf ortabl e wor king. (See photobelow.)+10'OAllE.R1R\2 7 kDIG..2 VZENE.RLEDITitl e of IdeaMail your idea alongwith this couponto : NewIdeasRadio-Electronics,200 ParkAve. South,New York, NY 10003I agreeto the aboveterms . andgrantRadio-Electronics MagaZine the rightto publish my ideaandto subsequentlyrepublishmyideaincollectionsor com-pilat ions of repr ints of simi lar artic les. Ideclare that the attache d idea is myownoriginal material andthat its publi-cation does not violateanyother copy-right. I also declare that this mater ialhadnot beenpreviouslypublished.Zi pDateStateSignatureStr eetPrintNameCityRZlOOK"BUI, Mom, I liked the green/aces-theywere scary ."about one milli ampwhen idling, and about20mill iampswhentheLEDislit.Thecircuitcan beadaptedtoworkwithbattery-powered circuits requiring betwee n6and 18volts; the only change s neededwould be a lower-voltage Zener and smallercurrent-limitingresistor in thecaseofvol-tages below nine volts , and a larger resistorforhigher voltages.-Donald F. RickliesFIG. 1The low-battery indicator uses an LED tosignal when the battery voltage has droppedbelowa pre-selected level. It is easy tobui ld, reliable, and inexpensive, and can beadaptedforawiderangeofvoltages. Thedevice shown is intended tooperate ina9-voltcirc uit.The sensing circuit consists of a 741op-amp set up as a voltage comparator , using aZener diode as a voltage reference. Theop-amp is inserted as a bridge between tworesistance ladders, one containing the Zenerreference, and the other a high-value linearpotenti ometer. The Zener isconnectedtotheinvertinginput oftheop-a mp, andthewiper ofthe potentiometer is connectedtothe non-inverting input. The top and bottomof the bridge are connected to Vee andground, respect ively .When the voltage at the wiper of thepotent iometerdrops belowthevoltage setby the Zener, the output of the op-amp goeslow; that turnsonthe LEDconnectedbe-tweenit and Vee . The LED turn- on voltage(f)oZoa:I-oW...JWoo-ca:84NEWLITFormoredetailsuse thefreeinformationcardinsidethebackcoverMICROCOMPUTERGAMES, isacolor 2-pageletter-si zed flyer desc ribing 19 compu-tergames. Thegamesrangefromsolitairelayouts(Voyager, Computer Football Strat-egy, Controll er), 1- 4 players (ComputerStocks and Bonds), 2 - 4 players (ComputerForeign Exchange) , upto as many as 20players seeking to conquer the universe(Galaxy). FreefromTheAvalonHill GameCompany, 4517Hartford Road, Baltimore,MD21214.CIRCLE111 ONFREEINFORMATIONCARDHEX- TOOLCATALOG, No. SO-267, is4-color , 8pages , andcontainscompletede-scriptionsandphotographsof Vaco'snewlyexpandedlineof uniqueball-endhex tools.Includedisanexpanded lineof " L" styleball-end hexkeys inboth inch andmetricmeasure, a brandnew line of inch and metricball-enddrivers, andnewball-end hexkeycaddysets.The catalogalso illustrates the uniquefea-tures and benefits of Vaco 's ball-end hextools. They alloweasy accesseveninres-trictedor hard-to-reach areas , set or removescrews at angles up to 30, and drive fasten-ers quicker and easier, saving time and labor.The No. SO-267 Ball End Hex Tool Catalog isfree upon request fromVaco ProductsCompany, 1510 Skokie Blvd., Northbrook, IL60062.CIRCLE112ONFREEINFORMATIONCARDTViVlDEOSYNC, Primer andProductNoteOpt. 005-1 is a 16-page primer, with13 draw-ings and 3 photographs; the special sectionsinclude theUnitedStat esNTSCbroadcaststandar ds and nomenclatur e, a discussionofPAL and SECAMsystems of color transmis-sions , and a glossary of TV and videoterms .Other sectionscover theoryof operation,typical setup, specifications, and the featuresandappli cati ons possi blewhen aTV/videosy nc opt io n is add ed to any curr ent ly-manufactured HP1700- seriesosci lloscope.Appl icationsdescribedarerelevanttosuchindu st ries as med ical imaging, consumervideo products, and televi sion broadc asting.Copes are free fromHewlett-Packard, in-quiriesManager, 1820EmbarcaderoRoad,PaloAlto, CA94303.CIRCLE113 ONFREEINFORMATION CARDELECTRONICS BROCHURE detailsa com-plete product linethat includes morethan55,000 variet ies of electron tubes, integratedcircu its, semiconductors , conne ctors , andcomponents. Eimac, RCA,PhilipsECG, andGeneral Elect ricarejust afewof thehigh-quality lines of transmitting, receiving, andindustrial tubesand semico nductorsthat arelisted. The brochure isavailablefree fromAlpha Electronics, Inc., 136539th St. ,Brooklyn, NY11218. R-ECIRCLE114ONFREEINFORMATIONCARD35-MHZDual Trace/Dual TimeBaseLBQ-52435-MHZDual Trace/Dual Time BaseLBQ-524L(withsignal delay)35-MHZLSQ-52320-MHZDual TraceLBQ-52215-MHZSingle TraceHighSensitivityLBQ-513A15-MHZDual TraceHighSensitivityLBQ-514ACDcoI\)omoms::OJm:Il Master Charge VISA COD Money Order Check 260MotorParkway, Hauppauge, N.Y. 11787CALL FOR SPECIAL INTRODUCTORY PRICESTOLL FREE (BOO) 6459152N.Y.S.(516) 435-8080 85EIIIPIEIiTAll TRAIIIIIIGIII IllERSCIIOl CAIiIATCI.NTS INUITES YOUTOEXPLOEMICROCOMPUTERS,mAL SYSTEMS MORE, WITH STATE-OF-THE-ART EOUIPMENTYOU ASSEMLEAN KEmenozoa::l-oW...JW6Cia::86Without question, microcomputers are thestateof theart in electronics. AndNTS is t heonIy home studyschool that offersyoutraining for thisbooming fieldwitha choiceof 3production-model microcomputers.We'll explaintheprinciples of trouble-shooting and testing your microcomputer and,best of all, we'll show you how toprogramittodo whatyou want.You'll use a digital multimeter, adigital logicprobe and othersophisticatedtestinggear tolearnhow tolocalizeproblemsand solvethem.Webelievethat trainingonproduction-model equipment,rather thanhome-madelearning devices,makes homestudy more exciting andrele-vant. That's why you'll findsuch gear inmost of NTS's electronicprograms.For instance,to learn Color TV Ser-vicingyou'll build andkeep the 25"(diagonal) NTS/HEATHdigital color TV.In Communications Electronicsyou'll be able to assemble andkeepyour ownNTS/HEATH2-meter FMtransceiver, plus test equipment.Butno matter whichprogram youchoose,NTS's Project Method of instructionhelps you quickly acquire practical know-how.Send forthefull color catalogin theelec-tronics area of your choice-discover all theadvantages of home study withNTS!NTS also offerscoursesinAutoMechanics,AirConditioning andHomeAppliances. Checkcardfor moreinformation. ... ..--_.-...---_.o Check if interested in G.!. information.o Check if interested ONLY in classroom training in Los Angeles.omoms::OJmJJ89Zip _3. TheNTS/HeathHN-89AMicrocomputerfeat ures f loppy disk storage, "smart " videoterminal , twoZ80microprocessors, wit h32KRAMMemory, expandab le to64Konboard. 4. TheNTS/Heath GR 2001DigitalColor TV (25"diagonal)feature sspecial ized AGC-SYNCmuting, filteredcolor andnew sol id- statehighvoltaget rip ler rectif ier.SimulatedTV Recepti on 4.3.Name Age --Address _Apt. City _State _T EC HNICAL T RADE TRA ININGS INCE 1905R e s id e n t a ndH ome-StudyS c h o o l s4000 SO. FIGUEROAST.. LOS ANGELES, CA. 90037-NAnONALTECH-NicALSCHOOLS--'I4000SouthFigueroa Street. Dept. 206-122 LosAngeles. California9003 7Pleaserush FREE color cat alogon cour se checkedbelowo MicroComputers/MicroProcessors 0 Aut o MechanicsoCommunications Electronics 0 AirConditi oningo DigitalElectronics 0 Home Appli anceso Industrial Technology 0 Color TV Servicing,-NATIONALnlE;TECHNICALLII;I SCHOOLS1. TheNTS/Rockwell AI M 65DedicatedMicrocomputer A Singleboardunit featuring onboardprint er and di splay-4KRAM(expandable ). Appli cationFunctions:Central processor-Controller/Monito r-Development System. 2. " TheNTS/SYM-l Microcomputer" 6502BasedCPU-4K bytes ROM(expandable)- lK RAM(expandable). 51active I/O lines for versatile interfac ing: diskdri ves, ASCII key boards, cassette tape, etc.STATE OF SOLIDSTATEMeasuringrelativehumidityROBERTF. SCOTT, SEMICONDUCTOREDITOR1------ -- - - - - - - --r- - - - - - - - - - - - - --,-- - - - - - - - - - - - - ---lThesensorThe elec tro-humidity sensor has ahygrometric element whose impedancechanges with changesin relative humid-ity. The hygrometric portion of the sensoris onthesurface ofa chemically treatedstyrenecopolymer plasticwafer. Watervaporis sorbed or desorbedby means ofadsorption (the adhesion of molecules to asurface; not the same as absorption). ThatAKNOWL EDGEOFTHERELATIVEHUMID-ityat anygiventimecanpennit us, orothers around us , to make decisions thatcanaffect our health, comfort andper-sonal safety. Inaddition, the measure-ment of relative humidity (abbreviatedRH) is vital in such areas as food process-ing, air conditioni ng, packing,photogra-phy, paper andlumber producti on, andchemi cal manufacturi ng. Knowing theRH- along with the temperature-canallow airport operators to predict fog andrunway icing. Si mi larly , farmers andnurserymencanpredict dewand frost;andhighwaysafety authorities can fore-cast dangerous fog andicing on bridges.Elec t ro nic ci rcuits for humiditymeasure ment have rarely appeared in thepre s s beca use humi dit y-sensit i vetransducers have been expensive and sel-domavai lable to the electronics con-structor and hobbyist. Now, for aboutten-doll ars-worthof semiconductorsanddiscretecomponents, andless than sixtydollars forthehumidity sensor, you canbuild a dir ect-reading elec tronic hy-grometer. Th e devi ce , described inNational Semiconductor's Appl icationNote AP256, is designed around thePCRC-55 humidity sensor, fromPhys-Chemical Research , and a linear ato10-voltDCmeter.RHSENSORFIG. 1SCALINGRECTIFIERANOFILTERAOOITIONAL'-- LINEARIZING CIRCUITRYOUTPUT

lOOK'042N2222A-=10K'R41.5MEG ....10K

+ -5.6KI BREAKPOI NTAM?L.."+ +15V

61 R3'---;' V 39K1/2 LF353300K150K+15V 1/2 LF353C150K >---'-- 12100% RH IC2.aTRIM 2+ 4- 15V39K 1/4 LF347 OUTPUT. lOOK AMP. - - - -4- ..,p V-= OFFSETANOGAIN15VlOOK1/2711-=FIG. 2f':::\\ " 200pF\ji) 710SENSOR +PCRC55_ LOG AMP- 1/4 LF347lOOKr---_ -'0=-t l l LM340L-12 I

+15V'10K LF347 ANOLF353RUNON 15V SUPPLY.4lmRHTRIM 01,02.03 AREONLM389. = 1%METALFILMl ALL UNMARKEOOIOOES AREl N4148- OUTPUTOV-l0V =0%-10lmRHTRIM@'1MEGRl10K'10K 4fJ

I C3 >l-'" 16V__ ,---,(,If' 03l K :I -='1-4-__""ro' ---l072 II :I 1 3.45V II -= -= ZENER -I IL-.J1.5K LM3296.9V .VOLT II-AGEREF "':120\1'- --------- - - - - - - - - - - - - - --'Y'VIr- - - ......- -Y\fIr---, _ lr----....... - 2K

6 IC1.b 7.-- - - ---11.-;--=15 lK+15V--1 _ 4 OSCILLATOR13 I C1 a+ - 15V1/4LF34715V0.002t(/)oZoa::I-oW...JWooa::90'--- - . - - -.- - - - - - - - - - - - - - - - - - - - - - - - - - - - - .....Jresults in the sensor's having a very rapidresponse to changes in relative humidity.A single sensor covers the complete rangeofrelativehumidity-from0to1009'0 .Thesensor shouldbeexcitedonlybyAC voltages (preferably sinusoidal wave-forms) of at least 20 Hz with no DC com-ponent. Sustainedoperation withaDCvoltage, or ACwithaDCcomponent,causes ashift incalibration. Themax-imumallowablecurrent is onerrtA.Figure I is a block diagramof theelectronic hygromet er. An amplitude-stabilized squarewave drives a precisealternating current through the sensor.The se nsor's output curre nt feeds acurrent-sensitive logarithmic amplifier tolinearize the response. Theoutput of thelog amplifier is scaled, recti fied, and fil-teredtoprovideao-IO-volt DC-outputrepresentingRH' sfrom0to100%.A practical circuitIn Fig. 2, a symmetrical squarewaveisgenerated by ICl-a, an op-amp with posi-tive feedbackapplied to cause it to oscil-late. The combinati on of constant-currentsource IC4 and its associated diode-bridgeclamps thesquarewaveoutputofICI-a at +8volts. IC4 has apositivetemperature coefficient of 0.033%/oC,which almost completely compensatesforthenegative0.036 %/oC temperaturecoe ffic ie nt of the PCRC-55 senso r.(Mount IC4closetothesensorsotheywill be at the same ambient temperature;that waythetemperaturecoefficient ofthe complete instrument will approachzero.)Thesquarewave is buffered, and thenfed through the sensorinto the summingj unctionof ICI-c. On negative-goinghal ves of the squarewave, the VBE/Iecharacteristicof QI , intheICI-c feed-bac k loop , gives th e a mpl ifie r alogarit hmic amplitude -response . Onpositi ve-goinghalf-cycles of thesquare-wave, feedback through the diode to thesumming junction ensures that this pointremains at a virtual ground so the sensoralways"sees"the required symmetrica ldrive-waveform.The output of the log amplifier goes toICI-d, anop-amp used to sum-in thecalibration atthe 409'0 RHpoint , andtoprovide adjustable gain fortrimming theoutput to the proper level for a100% RHreading. The output of ICI-d is filtered toDC by thelOOK resistor andIO,uF capa-citor andthenfedtoIC2-a, theoutputamplifierIC2-b compensates for the sensor ' s de-partur e from linear response below 40%RH. It does that by altering the gain of theoutput amplifierwhenitsinput drops toabout0.36volt---correspondingto40%RH. The invertinginput of IC2-b , thebreakpoint amplifi er, istiedtothenon-invertinginput of theoutput amplifier.When theinput to those parall eledgatesUsefulness- Measure capacitors 10pF- leakage 1 nA or .005C.V.,whichever is greater. Accuracy - To 2%depending on range. Dependabllity -Ruggedizedconst ruction; 1 yr. warranty.Versatility - In ci rcuit measurement ofcapacitanceandleakage. Output signalproportionate tomeasurement. Portabil-ity - 350 Hr.Batt ery life.' To 25.000"F withexterna l volt meterSand check. address(NO P.O. BOX) plus $3.50Handlin g. CT res. add7'h %tax.Phone or ders : (203) 423-7940ANDERS PRECISION INSTRUMENT INC.4 Bri dg e St . Pl aza, P. O. 80x 75 Williman tic. CT 06226CIRCLE29ONFREE INFORMATI ONCARDomom

COmJJ91DO$49,sCABLEINCLUDEEPSONTO APP EPARALLELINTERFACE !FLOPPYDISKDRIVEPROTOTYPING CARDS$28795Apple$19.95TRACKZERO MICROSWITCH IBM$49 95DDS3.2.UDOS3.3 Fourtn PASCAU CP/M . D't;t:r:es::::CARDFOR ABOVtggooEXTENDERCAR:p$FOR APPLE.* I6.9SFOR I.R.M*I9"Components Express,INC 1380 E. Edinger, Santa Ana, CA 92705 (714) 558-3972for APPLE6KRAMCARLANGUAGE TRANSPARENTTltJiil_iiiiiiiiii_iiii_iiiliiiiiiiili_..".699 5COEXFACTORYWARRANTVVIDEO1. CONTRAST1O 04. HHOLO12" BLACK*WHIUMONITORFULL FACTORY WARRANTY$7995'DOYOU KNOWWHERE YOUR COMPUTER.IS TONITE by AMDEK .VISION-8080x24 Vide '51/4" - 100PERBOX D' I C 24ALL CERTIFIED - 100% ISP ay ard GUARANTY$14900Vista Computer Company's new Vi si on-BOboardis aABOVE WITHHUBRINGS sophisticatedyet easytousevideo display card for$16900theApple' computer.92 CIRCLE33ONFREEINFORMATIONCARDYOUR EXCITINGNEW HOBBY! ORGAN&PIANOKITS50Cpot enti al at IC3' s i nvert i ng ( - )in-put. The range of val uesfor R2canbefairly widebecausetheexact chiptem-peratur ei s not import ant as l ongas it i sstable. Finall y ,remove the groundfromQ2' s base andthe chi pshoul dreachthepredeterminedstableoperati ngtemper a-turewithi n100 ms. Youcan checktem-peratur estabi lity by readi ng Q3' scol-lector voltage whil e bl owing on IC3. Themeasured vol tage shoul d remain constantwithin100p.V(O.OYC) .CalibrationTo cal i brate the electronic hygrometer,connect a35Kresi stor in pl aceof thesensor and adju st the 150K100%RH TRIMpot for 10vol tsoutput. Now, substi tutean 80-megohm resi storfor the sensor andsetthe40 'k RHTRI Mpot f or4vol ts attheoutput terminal. Repeat theJOO'kRH TRIMand40'k RHTRI Madj ustmentsuntil they"no longer interactwith each other. Final-l y, subst i tutea60-megohmresi stor forthe. sensor andsel ect a39Kresi stor forR3; that will developa2A-volt outputcorre sponding to 24%RH. It may benecessar y to sel ect aparticul ar 1.5-megohm resi stor for R4 to minimizejitterinthe meterreadi ngaround the 24%RHpoint.As thi s i s written, the sensor i spriced at$57.00,$54. 00, and $51.50 each,inlotsof I to 24, for devi ces with RHdeviationsof 1%, 1.5%, and 3%, respective-Water covers over three-fourths of theEarth's surface, and there is always somemoistureinthe Earth'satmosphere-even over the driest desert. At times, asmuch as 4-5%of a portion of the atmo-sphere is water vapor or water inagaseous state. The variation of theamount of moisture in the air (humidity) isinfluencedbygeographiclocation, tem-perature, andwindcurrents. Themostimportant of thoseistemperature. Heatcauses some of themolecules of theEarth's surface waterto escape into theastmosphere.Saturation occurs when, at some tem-perature, therates of evaporationandcondensation balance. The space abovetheliquid containsall the watervaporitcan hold.Whenthat happens, theair issaturated. The amount of vapor a volumeof air can hold before becoming saturateddependsonthe temperature; thehigherthetemperature, themoremoisturetheair can hold. Air can hold four times moremoisture at 70F than it can at 32F.Absolute humidity is a measure of theactual amount of moisture in the air at agiven temperature. It is expressed eitheras the number of grains (one seven-thousandth of a pound) per cubic foot ofair, or in termsof pressurein millibars or ininches of mercury.Relat ive humidity is the moisture con-tent of the air expressed as a percentage.It is theratio of the absolute humiditytothe greatest amount of moisture the air iscapable of holding at the same tempera-ture. As ananalogy, consider aquartbottle that is half full of liquid. The ratio ofits actual contents (one pint) to its capac-ity (one quart) is 50% Similarly, a mass ofair that is holding half the moisture possi-ble at a given temperature has a relativehumidity (RH) of50%When the relative humidity is high (60%to85%) wesaytheweather ismuggy.Evaporationof perspirationisslowandwefeel overheated. Weareuncomfort-ableasit accumulatesonourskinandclothing.Whentherelative humidity is toolow,perspirationevaporatestoorapidlyandweareuncomfortablychilly. Prolongedexposure causes our throat andnasalpassages to become dry. When it comesto personal comfort , temperature and rel-ative humidity are closely related. We en-joy relative humidities in the range of 45%to 55%.Indoors inthe winter when relativehumidity is low, the comfort range isaround68-74F. Warm-air heating sys-temsdryout theair andweoftenusehumidifiers to raise the moisture contentto a comfortable level. On a muggy sum-mer day, wemayusea dehumidifier tomake indoorair drier. An air conditionerdehumidifiesas it cools.Dew point is the temperature at whichair, as it cools, becomes saturated (RH is100%) and waterdropletscondenseoncool surfaces such as grass and plants. Ifthedewpoint isabove32F, thecon-densateisdew. Whenthedewpoint is32F or lower, the condensateforms icecrystals that we call frost. R-EUNDERSTANDING ATMOSPHERICMOISTUREoFreeInfo. Pack::::I Organ0 PianooCatalog& DemoRecord"'"C'as p 56;Name _Address _CIty Sta te __Z,p _ _Phonet __,Repinquiriesi nvited... .... :., Q" .. . .- ._. FlJf Fret Infonnation M40Call Toli Free 800 2 333865PA71 72994 327

. . .. msend..c::::I",._.. .- !!JEnjoyfantasti csavings by assern-bli ngyour ownorganor piano.!!JIt' s easy.Notechnicalknowledgerequi red.!!JJust followour clear.picturedinstr uctions.!!J Choose frommanymodelsfromportabl es toconsoles.!!JAsk about ourinterestfreeinstallment plan.drops bel ow0. 36 vol t, the output of IC2-b swi ngs positi ve; that turns on tr ansistorQ4 to produce the requi red change intheoutput amplif ier. Transi storQ4i s turnedoff for RH values above 40%, so lineari tyis then determine d solely by the l ogampl i fier.Transi stor Q I, in the l og- amplifierfeedbackloop, i s extremelytemper atur esensi tive and can adversely affect the per-fo r mance of th e ampli f ier. To com-pensate for that , the designers at NationalSemiconductor came up wi th auniqueci rcui t appl i cation. Transi stor s QI, Q2 ,andQ3are discrete NPNdevices onthesame subst rate as the audi o po wer -amplifier inIe3, anLM389. Transi storQ3 serves as the on-chi p temperatur e sen-sor whi le Q2 i s used asthe on-chi p heater.The audi o amplifi er se nses th etemperature-dependent V BE of Q3 and us-esit todriveQ2andheat thechi ptoatemperatur e(ty pically50C) set by thereferencevoltageat thej unctionof RIand R2. Th at ci rcui t stabi l izes Q I's tem-perature and makes it immune to changesinambient temp erature .To adj ust thetemp er ature- stabil i zin gci rcui t , groundQ2 's base, applypowerand then measure Q3' s collectorvol tage.Makeanot e oftheambient roo mtem-perature. Now,calcul atewhat Q3 ' s col -l ector voltagewi ll beat 50C; allowi ng-2.2mV/C. Adj ust thevalu e of R2todevelopa vol tagecl ose tothe calcul ated(/)oZoa:I-oW.....IW6(5a:A MIXER for OJ's- Studill'S- BrDadu slrr'sCIRCLE37ONFREE INFORMATIONCARDEQUA LI ZERS PRICEDFROM 5119. to5690.LEDMETERS PRtCES548. to5219.-4.arou-{javfu/(;,s . . _0 .- ' I I" ,. _-"'O'r r 1 ' I : '. 1 '. _ .- LJ", l -r:' . " I .. -_ .. ....,...&1 .."'"- v-. :: ,,:, . .. -"Call or writ e forfull product informa tion, and pr i cin g to:AaRON-GAVIN123 SouthMcClay Street . UnitF.SantaAna. CA 92701. (714) 957-8710super-beta bipol ar input stage that yields avery low input-voltage noise, and a highcommon-moderejectionratio(CMRR).For addedversatility, the internallysetgains can be increased by adding externalresistors. A 16-pin DIP-packaged device,which should soon be available, will fea-turepin-strappable gainoptions of 10,100, and1000. TheLM363 ispricedaslo was $9 .6 0 in 100-piec e lot s. -National Semiconductor , PO Box70818,Sunnyvale, CA 94086 .Super-fast op-ampThe Harris HA-2539 op-amp features a600V/j.ts slew rate and a 600-MHz gain-bandwidth product , makingit anidealdevice for use in pul se- and video -amplifiers, wideband amplifiers, high-speedsample-and-holdcircuits, andRFoscillator s. Full IO-volt output swingand high open-loop gain make this Harrisde vi ce useful i n high -sp eed dat a-acquisition systems.Power bandwidthis9.6 MHz, offsetvoltage is 3 mV, and input-voltage noiseis 15 nV1Hz. The device is packaged in a14-pinceramic DIP. The HA-2539-2,manufacturedfor militaryuse, operatesinthe - 55 to + 125Ctemperature-range. The HA- 2539-5 , intended forcommercial applications, operates in theOCto +75Ctemper ature-range.-Harris Corp. , Analog Products Div. ,PO Box 883, Melbourne, FL 32901.R-EIy. To obtain the latest pricing and data onthe humidi tysensor , wri te to Phys-Chemical Research Corp. , 36W. 20thSt., NewYork, NY10011. BesuretospecifythePCRC-555because the com-pany has other sensors whose characteris-tics are not suitable for the circuit that hasbeendescribed here.Semi conduct orcatalogSGS Shortform '82 is a 72-page cataloglistingpertinentapplication informationand technical data on the SGS lineofsmall-signal andpowertransistors; andlinear , low-powerSchottky TTL, MOS,and CMOS4000/4500 logic-series IC' s.Also included in a list of SGS data books,technical notes, design notes, and thenamesandaddressesofdistributorsandrepsthroughout the U.S.-SGSSemi-conduct or Corp. , 7070 E. 3rd Ave. ,Scottsda le, AZ8525 1.Inst rumentationAmplifier ICThe sta ndard th r ee -o p- arnp in-strumenta tionamplifier with its morethan ahalf-dozendiscreteexternal com-ponent s has beenreplaced byNational' sLM363. Alow-cost, high-performancemonolithic instrumentation amplifier, theLM363 (and the LMl63military version)comesinan 8-pi n TO-5package . It re-quiresnoexternal resistors for accuratefixed gains of either10, 100,or 500 (onegain per package). The device has aomom

CDm:D93SPECIAL (Min. 5pes. each)2SC867A 2.95 AN214Q 1.502SC1034 5.95 STK439 7.252SC1114.. 3.45 UPC1181 H. .. 1.952SC1308K... 2.25 UPC1182H. .. 1.95CIRCLE28ONFREE INFORMATIONCARDDIClITRONELECTRONIC110 Hillside Avenue, Springfield, N.J. 07081201-379-9016, 379-9019ECG IS A TRADE MARK OFPHILIPS ECG.DIGITRONIS NOT ASSOCI ATED IN ANY WAY WITHPHILI PS ECG.Call Toll-Free800-526-4928COD ORDERS WELCOME(Min. order $25)CALLOR WRITEFOR OUR1982PRICE LISTTECHNICIANSREPAIRMEN HOBBIESTWE CANSUPPLYYOU ALL YOUR NEEDFOR YOURMAINTENANCE, REPAIR WORK &DESIGN.AMERICAN,JAPANESE, EUROPEAN TYPESREPLACEMENT FOR ECGeCHECK THIS' (Min. 5pes.each)YOUR ECGeYOURTypeNo. PRICE TypeNo. PRICE123A . . . . . . . . .. .28 500A.. .. .. . . . 8.95152 60 523 , 10.75153 65 526A 10.95165 2.25 3.75238 2.25 3. 753 YEARS WARRANTY ONEXR PARTSUSEYOURREADERSERVICECARDDON'TFORGET36CHANNELREMOTECONTROLCABLE CONVERTER$88.00LIN DSEY JETIWIRELESSTH E ULTIMATE CAB LE T.V.CONVERTER58 CHANNEL INFRARED. REMOTE CONTROL-- ' l COMPLETLY. ._ - PROGRAMM ABL E. $169.00Send$1forComplete Cat alogVISA. MASTERCARD. CODAMATEURMICROWAVEANTENNA 26DBGai n Ad vancedDownConverter Complet e- Readyto Inst all$119.00DIRECT VIDEO SALESP.O.BOX1329JEFFERSONVILLE, INDIANA47130CALLTOLL 'FREE1-800-626-5533CIRCLE 89ONFREEINFORMATIONCARDSERVICE CLINICA commoncauseJACKDARR, SERVICEEDITOR(f)ozoa:f-oUJ....JUJ6o

9.9511.75Z80 AZ80 AZ80 A650065026502A65046 505650765206522653265513.003.501.2010/1.006/1.006/1.00MaleFemaleHood16K APPLERAM CARDUpgrade your 48K Apple/Itoful/64KBAREBOARD 14.00KIT 39.90ASSEMBLED&TESTED 45.00LEDSJumboRedJumboGreenJu mboYellowCONNECTORSRS232RS232RS2324.754 .7514.904 .508.759.754.505.208.506.8539.0029.009.259.956 .506.505 .506 .506 .5025 .0049.00823982438250825182538253-582558255-5825782598272827582798279-5828282838284828682878288828980006 .957 .593.907.9534. 957 .758.7529.0039.0014.9529.9527.953.451.803 .751.752.451.804 .5019.004 .75803580398080A8085A80888155815681858741874887558202820582128214821682248226822882378238CMOSORDERTOLL FREE(800) 538-8800(800) 848- 8008(CALIFORNIARESIDENTS)ALLMERCHANDISEIS100% GUARANTEEDLINEAR.3 0.90. 90. 902.491.90.90.6 01.90. 90.90.901.202 .201.501.201.201.201.201.201.901.20.901.901.901.902.70.90.901.901.90. 9 0.904082408540864093409840994502450345084510451145124514451545164518451945204522452645274528453145324538453945434555455645814582458445851.15.90.45.90. 901.10.3 5. 75. 3 51.60.6 0.75.90.452.90. 85.901.20. 75.75. 75.90. 9 0.5 0.50.90.901.39.75.39.30. 3 5.3 0.30.30.3 0. 90.30. 3040174018401940204021402240234024402540264027402840294030403440354040404140424043404440464047404940504015405340604066406840694070407140724073407540764 0 7 84081. 2 9. 7 5.4 92.451.691.251.691.49. 5 5.95.952.452.45.5 9.953.703.703.70.35.35.35. 2 5.3 0. 3 0. 90. 2 5. 90. 4 5.4 5.30. 3 0.45. 90. 90.4540004001400240064007400840094010401140124013401440154016LM741LM747LM748LM1310MC1330MC1350MC1358LM1414LM1458LM1488LM1489LM1800LM1889LM3900LM3909LM3914LM3915LM391675451754 5 275453.3 2.751.25.641.651.701.493 .75. 5 93 .90. 7 92 .251.251.00.38.6 5.951.45.99.49.95Disc Controller1771 16.001791 27.951793 29.951795 49.951797 49.95Interface8T26 1.658T28 1.958T95 .958T96 .958T97 . 958T98 . 95DM8131 2.90DS8836 1.25LM301LM308LM309KLM311LM317TLM317KLM318LM323KLM324LM337KLM339LM377LM380LM386LM555LM556LM565LM566LM567LM723LM733IC Sockets ST W/W8PIN . 10 .4914PIN .12 . 5 016PIN .15 .5718PIN .20 .8520PIN . 25 . 9 922PIN .25 1.3024PIN . 25 1.4028PIN .35 1.5040PIN .40 1.80ST = SoldertailW/W =Wlrewrap.80.8 0. 802.80.60.491.603.25. 4 91.95. 951.201.79.99.991.751.491.491.491.95.89.8 9.69. 6 9. 9 91.691.401.151.351.89.591.791.791.591.592.89.751.891.651.852.109 .502.992.392 .392.392.392 .391.651.651.651.6574LS25374LS25774LS25874LS25974LS26074LS26674LS27374LS27574 LS27974LS28074LS28374LS29074LS29374LS29574LS29874LS32474LS35274LS35374LS36374LS36474LS36574LS36674LS36774LS36874LS37374LS37474LS37774LS37874LS37974LS38574LS38674LS39074LS39374LS39574LS39974LS42474LS44774LS49074LS66874LS66974LS67074LS67474LS68274LS68374LS68474LS68574LS68874LS68981LS9581 LS9681LS9781LS9874LS123 . 9574LS124 2.9074LS125 .9574LS126 .7974LS132 . 7574LS136 .4974LS137 . 9 574LS138 . 7574LS139 .7574LS145 1.1074LS147 2.2074LS148 1.2074LS151 . 7574 LS15 3 .7574LS154 1.7574LS155 .8 974LS156 .8 974LS157 .7 574LS158 .7574LS160 . 9574LS161 . 9 574LS162 .9574LS163 .9574LS164 .9574LS165 . 9574LS166 1.9574LS168 1.6974LS169 1.6974LS170 1.697