YOUR 0 CO PUlER4O-PAGEBUYERSGUIDE $1.25 OCTOBER1980the Unicorn-l robotlor LED bar-graph displayslikola Tesla-the pioneerHow to use flasher LED's.Haller'ssuper hi-Ii amplUier kit One-Ie digital panel meter10I7189648783ofromCooperThe'Ibolmakel"I made it despite myself."SuccessForcesCanyoubesuccessful despiteyourself?Here'showI didit.By J oseph Sugarman, PresidentJS&A Group, Inc. .It's ajoke. I'm cons idered one of Amer-ica's top copywr iters and mail order entre-preneurs.I neverfinishedcollege ,never tookacourse in business, advertising or creativewrit ing, and eve n flunked Engli sh.On top of that , I failed at almost every-t hing I did . Mylistof failures would fillan encyclopedia.Now you proba bly expect me to tell yout hat it was fai lure after failure unt il I hitupon t he "wealt h formula" or t he "secretto success" or some other trite expression.Not t rue.ONLYSIXREASONSWhat I'vefound about successis quiteopposite the formulas you've read aboutor t hemisconcept ions you've heard.I si mply took my fewsuccesses andmany failures and discovered six reasonswhyIfa iledand sixreasons whyI suc-ceeded.The reasons Isucceededseemedlikeforces. Whenever I followed t hem, Iachieved success. Whenever I didn 'tfoll ow t hem, I failed. I soon called themSuccess For ces.I used Success Forces to build my busi -ness from t he basement of my home int oAmerica's largest si ngle source of space-age products. I was successful. But wasit acoi ncidenceorwas it a directresultof Success Forces? I really didn't kn ow.MATERIALTHINGSIf you measure success by mat eri althings, I achievedquitea bit: severalcars, airplanes, snowmobi les , motor-cycles, four beautiful homes -all themater ial things I imagined I' d everwant.And I had recognition. My successstorywaswr ittenup inseveral maga-zines. But it wasn't unt il after I revealedmy Success Forces in a few speeches t hatI realized my concept wouldwork forot he rs.I was gettinglet t ers frompeople whotoldmehowone ofmySuccessForceshad changed their lives. Others told meof how they used Success Forces to makeextramoneyor achievegreaterhappi -ness. Still others who always t hought oft hemselves asfailures, became success-ful despit e themselves.But thewhole thing seemed st range t ome. Was SuccessForces ori gin al ? Some-t hing like it had to be in some othe rsuccess book. SoIread. Iboughteverysuccess book Icouldfind. I studied Chi -nese ph ilosophy. I boughtevery mot iva-ti onal cassetteth at was offered. AndIthoroughly st udied the materi al.I t he n discovered whymy concept wasindeed different . Success Forces let s yoube yourself, and guides you towardsmaking si mple choices t hat can ul ti-mat el y change your life. If you make t heri ghtchoi ces, you are literall y forced intosuccess.MY$2,000SEMINARAlthough I was convinced that my con-cept wasdi fferent , Iwantedtobeabso-lutel ysure it wouldwork . I decidedtoconduct asemi narwit h a select group of16peoplewhowouldbewillingtopayhandsomely to learn my philosophi es.My five-dayseminar cost eachpartici-pant $2,000 and I held eight of them. Allw.ere sold out.The success stor ies result ing from eachseminar arealre adyhistory. It au ghtaTexasfarmer , aNewZeal andrugmer-chant , a lady from Australia. There werepeoplefromall walksof Americanlife,manyof whompaidt he ir last $2,000toattend.Not all of theparticipantssucceeded.But so many did become successful and somany told me late r how I lit erall y chang-edt he irli ves, that I wasconvinced Suc-cess Forces should be available for every-body to use.NOW AVAILABLEI am now making my concept availa blein a hard bound book entitled"SuccessForces."It contains examples frommyspeechesandthephilosophiesfrommyseminar t hat participants paid $2,000tohear .Afewof theSuccessForcesyoumayal ready knowand have been subco n-sciously following for years. Others, youmayhavebeenfighting, thinkingthatyouwould fail when all along you wouldhave succeeded. Afewof my SuccessForces r equire act ion - the type of actionthat everybody can take an d that re-quires no special skill.Thisis not astep-by-ste p book on howtoget intoabusiness thatpromises"ALazy Wayt o Riches," orawayto "QuitYour Present J ob." It does not matter ifyou are in business nor whether you wantto work hard , take it easy, or just plain besuccessful.TEACHHIMTOFISHThere's a say ing : "You can feed a manafish and he'll eat for a day. But teach aman tofishand he'll eat foralifet ime."My book will help you for a lifet ime.I'm not somebody who wri t es a book onhowtomakeafortuneand thenmakesmy fortune from the sal e of the book. I'vealready madeit . Nor am I goingto sendyou a cheaply pri nt ed thi n paperback.That' snot mystyle. Mybookisa 200page hardcover volumet ha t I guaranteeyouwill bothenjoyand benefit from. Infact, I will go one st ep further. After youread it , wait oneyear. Ifyouhave notnoti ceabl y benefited from reading SuccessForces, return your book to me and I willrefund your money in full. Success Forcesmust give your lifeadditional meaningwit hin oneyear or your moneyback. It' st hat simple. This one -year returnofferapplies only to those individual s purcha s-ing my book via mail order.EASYTOORDERI'vealsomadeit easy for youto ordermy book. Credit card buyers may call mytoll-free number below or send yourcheck or money order for $9.95 plus $2.00post ageand handling(Ill inoisresi dentsplease add 6%sales tax) payable to:JosephSugarman , Dept . RA, Two JS&APlaza, Northbrook, Illinois 60062.I'vebuilt mybusiness andreputationon providing solid va lue to the consumer.Success Forces represents myul t imateproduct and my greatest value . Orderacopy at no obligation, today.

OTHAT THINKCall TOLL-FREE 800 3236400In Illinois Call (312) 5647000 J osePJ:l Sugarman, 1980o

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INFORMATtON ON DEMAND DATA 100Ml\ILCALL OATA MAILCAl LMA ILDELIVERy I NFONEWYORK TIMES NEWS SUMI"ARY OATA NYTNSNEW YORK TIMES CONSUMER DATABAS. NYTC08POLI TICAL ACTI ON REPORT OATAPERSONA. L C"LENOAR &NOTEBOOK. OATAPERSONA.L FIKANC, OATAPERSFISCIENCE &ENGINEERING OATASCtEHGSELF-PERCEPTION OATA ESP. \lATALORESPORTS OATASUGGESTION BOX O"TASUGBOXTRAVE L CLUB OATA TRAVELUNITEDPRESS INTERHATIONAL (UPI) OATA I,)ANEWSUSER DIRECTURY OATA USEUIRVOICEGRAM OATA VOICEGRAMWEATHER OATA WEATHRWI SDOMOF THE AGES WISOOMoobCDm:xlrrComputers cannot act ontheir own-they have tobetold what todo.Here's adiscussion of several of thelanguages usedtoinstruct them.CIJozoa:f-oW-lW6Q-ca:78IFYOURRICHUNCLEPASSED AW,AY ANDLEFTYOU A MULTI-million dollar IBMcomputer, it probably wouldn't do youany good (unlessyou sold it). All you would possesswouldbeawell-designedpieceofcomputer hardwareunlesshealsoleft youthe software (programs) totell themachinewhat todo.The computer isamachine. It doesn't understand theEnglishlanguage. Yet itiscapableofperforming anend-less number of tasks, involvinglengthycalculations andcomplex procedures. Andthe computer can respond toacomputerlanguage, sotheobviousstepis todevelopalanguage that canbeunderstoodby humans andsomehowconverted to thelanguage a computer can follow.A computer program is a set of instructionsthat tell thecomputer what to do. Acomputer languagedefines therules ofgrammarandvocabularyforwriting instructions.If youdon't followtherules, thecomputer cannot under-standtheinstructions, andit will beunable toperform itsassignment.A statement, or instruction , in a computer program, is astringof elementsfromanalphabet that includesletters,digits andsymbols. Aset of rules, or syntax, establishesthe formof eachstatement which conveysa specific oper-ational meaningor semantics. Thus acomputer languageincludesthealphabet, syntaxand semantics.Computer languages inusetodaycanbegroupedintothree broadcategories: machinelanguages, assemblylan-guages, and problem-oriented languages. Both machineandassemblylanguages are consideredlow-level languageswhile a problem-orientedlanguage is concernedhigh level.Machine languageThe most elementary language is machine languagesinceit is the only language thatthe computer understandsdirectly; anyother languageis "foreign"to thecomputerand thusit will not recognize or executeproper commands.Machine language is written with the computer's hard-. ware or designconfigurationinmindsotheprogrammermust bewell aware ofhowthemachineworks. Becausethevocabularyandgrammar rulesareratherlimited, ma-chine language is considered simple. However, becauseof thelimited vocabulary, a fairly long program is requiredtoleada computer througha relatively simple assignment.A machine-language program consistsof a list of instruc-tions inbinaryformtodirect thecomputer to perform anoperationor aseries of operationssuchasadd, multiply,read, write, or store. For theprogrammer's convenience,decimal, octal, or hexadecimal numbersmaybeusedandthen convertedintobinary numbers insidethe machine.Theoperation tobeperformedis given by a code that di-rectsthe computer to perform a specific operation and alsosupplies theoperand, whichis the quantitytobe operatedupon. Instructions in machine code are binary numbers, notlettersor words. Aseries ofbinarynumbersrepresentingavery small part ofamachine-codeprogram would looksomethinglike this: 'Operation Code Operand 1 Operand 201011001 01001100 11011010Toperforma simple addition of just two numbers wouldinvolvetheabovelisting of l 'sandO's , in thebinary lan-guage that makes the computer perform. Imagine theenormous sequenceofO's and I's requiredtoperformacomplex calculation!Obviously, the computer programmer whoattempts toprepare a lengthy programinmachine languagewill bepronetomakingerrors sinceit isatediousandtiresometask. The task is somewhat lessenedwiththe aidof anoctal or hexadecimal programthat accepts the program-mer 's inputs inoctal or hexadecimal (special numberingsystemsthat are moreintelligible tohumansthanbinary)andconverts them to binary.The advantages of machine-language programming are(1) theabilitytoinstruct thecomputer directlyand (2) thelowrequirement forsupportingsoftwareormemory. Thedisadvantages include(I) theneedfortheprogrammertohave full awarenessof themachine'shardwarestructure,(2)the lengthyandtedious effort involvedinwriting theprogramand(3) thelackofflexibility in using aprogramwrittenfor one computer onanother type. For example,a machine-languageprogramwrittenfor aMotorola6800-based computer cannot be applied, without extensivemodifications,to a computer using an Intel 8080CPU.Perhaps the greatest drawback to machine-languageprograms is their lack of intelligibilityto non-computerusers. A detailed machine-language program, with itslengthyseriesofO's andI's-or eventheiroctal orhexa-decimal equivalents-has nomeaningtothe student , en-gineer, businessman, or laymaneager toapplythecom-putertohisspecificapplications. Indeed, evenaprofes-sional machine-language programmer has quite a taskkeepingtrack of the meanings of the machine code.Assembly languageTo make computer programs easier to comprehend, sym-bolic languages weredeveloped. Suchalanguagemakesuse of letters or names for instructions, data and addresses .These names or "mnemonics" refer to the terms theyrepresent soa computer usercan, byassociation, relatethe termtothefunction. Anexampleof mnemonicsym-bols ineverydayuseisDODforDepartmentofDefenseand IRSfor Internal RevenueService. Onlythree lettersare used as shorthand identification, yet most peopleknowimmediatelywhat theyrepresent.Not all instructionsare as easytoremember asADD,SUB, or AND. But it is not toodifficult for theprogram-merto associate LA with "load the address" or P to punchacard. Suchuseof symboliccoderatherthanalengthystringofonesandzeroswasthefirst majorsteptobringcomputer-programming capability to the non-professionalprogrammer. If we wantedtohave thecomputer calculateX= A+B, where A=3and B=5, inassembly language,wewouldusetheassemblerinstructions listed in TableI.TABLE1Location Operation Operand1Operand 2 CommentsBegin LDA REG6 B Load B intoregis-ter 6ADD REG6 A AddA to register 6STA x REG6 Store register 6atXThe symbolic instructions listed inTable I wouldbetranslated into machine-language form by the assembler.Nowa non-professional programmer canwrite what'sknown as a source program, using symbolic language,with instructions or statements toguidecomputer activ-ities . Next, aprocessingstepisrequired totranslatethesource program(easy for a humanto write and under-stand) into an object program, which is a machine-languageprogramthat thecomputercanunderstand. Theprogramthat accomplishesthistaskiscalledatranslator. Itsout-put , theobjectprogram, is what thecomputerrequirestodirectits operation.The grammar of assembly languageis similar to thatof machinelanguage but thevocabularyis different. Sinceacomputer is still being directed , theoperationsavailableandthesequencing areunchanged. However, mnemonics,rather thannumbers , areused in preparing the program.Symbolic languages make computer-programprepar-ationeasier, since terms , rather than numbers, areused torelate tothe problem-solving needs.A profoundadvantageof symbolic language is the abilityit givesonetypeof computer toprocessprograms writtenin many different languages, provided a translator pro-gramisincludedwith eachlanguage. This means that onecomputer can handle programs written ineither BASICor FORTRAN (to be describedlater), as long as a separatetranslatoris availabletoconverteachinto thecomputer'smachine-language code.This first step to make programmingabit simpler iscalled assembly language, machine-orientedlanguage, orlow-level programming language. Although symbolicnotation makesprogram-writing easier than straight binarycoding, it takes about as manysymbolicinstructions towrite aprogramas machinelanguage does.Statedanotherway, there is a one-for-one conversion of language instruc-tions. Thus, theassembly-language programmerstill mustwritelengthyinstructionsand must be familiar with all thepeculiarities of thecomputer he is programming. For com-plex programs, manyof the abbreviatedmnemonicswillnot takeconvenient comprehensiveformandwill requireextensivecommentarytokeeptrackof all thedefinitionsof terms.The translator that converts the assembly-language(source) program into the computer object programiscalled an assembler and is usuallylocated inthe com-puter's memory. Asthesource program, writteninsym-bolic language, isentered intothe computer, the assem-bler converts each symbol into machine-languageform(or the object program). At this stage, the computer isonlyrecordingtheobject program in itsmemory, orontopunched paper tape, magnetic tape or disk. Whenthetranslationtask iscompleted, theobject programcanbeentered inits entiretyintothe computer; nowthe com-puter canunderstandthe instructions and data. and can pro-ceed toexecute the program.Assemblylanguage is an improvement over machine lan-guage, but is still machine-dependent. Every typeof com-puter requires its particular assembly language.Problem-orlented languagesThe next step inprogramdesignmakesthe computerhardware (and type of computer) relativelyunimportantwithrespect to thetask tobeperformed. This typeof lan-guage is known bysuchnames as: " problem-oriented, ""procedure-oriented," or , simply, "high-level." It ap-proaches the programming problemfromthe viewpointof thegoal to be achieved, rather than the specific machinethat will achieveit.Broadly speaking, there are two types of high-levellanguage-compilers and interpreters. Compilers will beconsidered first.Acompiler allowsaprogramtobewritteninEnglish-like termsand translates it directly into machine language.Withit, asinglestatement, such as"PRINT,"cancausea whole series of machine-language instructions to beexecuted. Fromthehumanpoint of view, a compiled lan-guageis much more efficient than assembly language.As withanassembler, the compilerfirst translates thesource-language programintoanobject programbeforerunning it. A program, that originally has been written usingacompiler cannot be run unless the entire program(or a com-pletesectionof it) has firstbeen translated(compiled) intomachine code. Here' s how a program would be compiled onalarge compute rsystem (smaller systems use floppy disksoOJm:D79enozoa:t;w...JW6Qc(a:80rather thanpunchcards):First theprogramis laid out, anddebuggedto the great-est extent possible (getting thebugs out of an already com-piledprogramis notthesimplest taskin theworld), usingcodingsheets. Then, assumingthat apunch-cardsystemisbeingused, akeypunchoperatorpunchesor codes onecardfor each lineonthe codingsheet. Thecompletesetof suchcardsis called the"source deck."Then, with thecompileralreadyin thecomputer's mem-ory, the programisfedintothe computerone cardat atime . After all thecards havebeenfedin, theprogramiscompiled, andanewset of cards, containingmachine-lan-guage instructions, is generated. This set is knownasthe"object deck." Since one "source" card may requireseveral machine-language instructions to be carried out,the object deck contains manymore cards than the ori-ginal source deck.After compilation, the code fromthe object deck isloadedbackinto the computer, and the programcanberun.The other type of high-level language we'll discuss istheinterpreter. Mostof theBASIC'sused with small com-puter systems are interpreters. Interpreters, like com-pilers, allowprograms to be written inan English-likeform, but operate somewhat differently internally. Themost significant difference is that no compilation takesplaceandthat thesourcecodeis alwaysaccessible.An interpreted language translates instructions intomachinelanguageastheprogramexecutes-inreal time-rather than "predigesting" themall at once, as does acompiler. Because an interpreter is constantly "inter-preting" (or translating)as wellasactuallyexecutingtheprogram, it tends torunmoreslowly thana compiledlan-guage. Furthermore, the interpreter retains no memory.of what it has interpreted so, even if it has alreadyexecuteda certainroutine a hundredtimes, it must interpret it anewwhenit encountersit for thehundred-and-first. Thismakesforaneven greater reductionin speed.Interpreters have their advantages, though. Becauseyouare always workingwithsource code, it issimpletomodify a programshould achange be necessary. Apro-gramcanevenbestoppedwhileit isrunning, altered, andthe runcontinued. This is animpossibilityif youareusinga compiled language. Also, while a compiled programmayoccupymuch less memory than aninterpretedone,the compileritself maytake upsomuchroominasmallcomputer that it would leavelittle orno memoryspacefortheprogramit wasintendedtorun.Machineandassemblylanguagesaredesignedtomatchspecific computers, and bear norelation tothe applica-tions the computers are intended to perform. Problem-oriented, or high-level, languages disregardthe hardwareaspects of the computer and concentrate instead ontheapplications. To simplify programming, it was desirableto develop different languages for different applications.Languages have been developed for mathematical andscientific needs, for business procedures , for text editing,andfor other specialized needs. Only one problem-orientedlanguage has been developedas a universal languagetoreplace all others: the IBMPL/I or ProgrammingLan-guage/ l.Thepremise was thatscientists, businessmen, engineers,and computer experts could programnearly everythingthey needed with this language. Unfortunately, the lan-guage issocomplexthat fewprogrammerscanhandleit.Secondly, apowerful computer is requiredto usethepro-gram. Andfinally, it turnsout that thescientificprogram-mer using PLII involves himself only withthe scientificportion while thebusinessprogrammer only identifies withthe business section. It maywell be that thegoal of anideal computer languageisnot unlikethat of auniversallanguage forspeech aroundtheworld. Wouldn'tit be con-venient tohaveonelanguagespokenandwrittenthrough-out the world? No needfor guidebooks , language-phrasebooks, language courses for the traveler-but as obviousas the needappears, the prospect of auniversal languageis far distant. Sotoo, perhaps for a universal computerlanguage.Advantages ofhigh-levellanguageWhat are the advantages of high-level languages?Pro-gramsareshorter, easier towrite, anddebugging (locatingerrors) is simplified. Programs written for a particularapplication can be supplied to users around the world,regardless of the computer they have, as long as a compileror interpreter isavailable for thelanguageused. And, ofcourse, there is noneed for the programmer tobecon-cerned with theinnerworkingsor detailsof his computer'shardware ormachinelanguage.Then whyarelow-levelassembly-ormachine-languagesstill in use? High-level languages require considerablememoryandprogramsrunslowersinceatranslationpro-cessisinvolvedbetweenthehuman-orientedandmachinelanguage. Oftenthecompilerisexpensiveandrequires alarge amount ofmemory. Ifaninterpreterisusedratherthan acompiler, translatingeachstatement andexecutingit, less memory isrequired. Thetradeoff is alossin effi-ciency sincetranslationmust beperformedeverytime theuser runstheoriginalprogram.Which is best? For the non-professional programmer,high-level languagesaremuchsimpler toprepareanduse;programs are relatively easy to comprehend fromthesymbols involved. Assembly and machine-language pro-grams, when properlyprepared, can makethe computerperformfaster; also, programmers familiar withthe par-ticular strengths of acomputer's hardwarecanmakethecomputer "dotricks" and thus operate more efficientlythan would be possible with general-purpose high-levelprograms. Even today, assemblyand machine languagesofferefficiencyunmatchedby high-level languages.Popular high-level languagesHigh-level languages, or problem-oriented languages,canbegeneral-purpose, or canbespecificallytailoredforapplications such as engineering, education, banking orprocess control. Over athousand languages are inexis-tence, someused only by a handful of specialists and othersenjoyingwidespreadusebyalarge number of computerusers.Amongthemost popular computer languages are:ALGOL (Algorithmic Language}-a math and sciencelanguageincommonuseinEurope.APL(AProgrammingLanguage}-alanguagetohandlelong stringsof numbers or letterswithease.BASIC (Beginner's All-Purpose Symbolic InstructionCode)-alanguagedevelopedtointroducestudentstocomputers: simplicityandease of usehighlight t his lan-guage. Widespreaduse withpersonal computers.COBOL (Common Business-Oriented Language}-theoriginal language designed for the non-profess ionalprogrammer for business , rather than scientific, appli-cations.FORTRAN (Fonnula Translation Language}-Probablythe most wide ly usedlanguage. Althoughorig inallyin-tendedforscientists, it is inwidespreaduse for businessapplications.LISP (List Processing}-a languagedeveloped by a groupat MIT tohandle list processing. Lists are f inite sequencesthat canappearin a large varietyof structures in the formof numbers, lett ers, or evencomputer words.Pascal-an extendedversion of ALGOL developed forteachingstructuredprogrammingtostudents.PU1 (Programming Language/1}-acomplex languagecombining the advantages of COBOL, FORTRAN, andALGOL. Thelanguagecontainsmorefeaturesthananyother language; however , becauseof its complexity, itis difficult tolearnand apply.RPG(Report Program Generator)-a language for re-questinganddefining reports.Languages indetailWouldn't it beideal if all computersunderstoodinstruc-tions writteninthe Englishlanguage? Yes, it would, butthere would always be problems. Human languages areextremelycomplexandyet imprecise. Wordsdon't meanthe samethingtoeveryone. For example, "watch" mayindicate "observe" to one person and "timepiece" toanother. Withcomputers, words andinstructionsmustbeexact,without ambiguitiestoconfusethecomputer.High-level, or problem-oriented, languages are agoodcompromise forefficientcommunications betweenhumansand the computer. It has been estimatedthat well overI,000high-level languages have been developed ; perhaps200 enjoy some formof popularity.Why so many languages? High-level languages are in-tendedtohandleproblems andthusdeal withamultitudeof applications. While manylanguageshavea rather broadappeal andapplication, there alwaysseemstobeareasonfor programmerstodevelopaspecificlanguageforaspe-cific need. There are high-level languages, for example,exclusively tailored for numerically-controlled machinetools, electroniccircuit design, hydraulicsystemanalysis,graphical analysisandother suchspecialized applications .ALGOLALGOL(Algorithmic Language) was developedinthemid-1950' s for scientific and mathematic applications.ALGOLismuchmorepopular in Europethanin theU.S.and is well respectedas a powerful language capable ofhandling verycomplex programs.One version of ALGOL of particular significance isthe " publication" version which many computer scien-tists use todescribenewprograms theyhave developed.Thus, there aremanyprograms publishedin ALGOLeventhough the programauthorsorpotential usersdonot havethe sophisticatedhardware to runor test the programs .Thepublication versionofALGOLis basedupon thetypefaces generallyavailable toprintersandthus includesup-per and lower case letters, methods to indent lines, andbold-face type.The language's power and versatility are assets whicharehamperedbythe needforarelativelylarge, slow, andexpensive compiler. Programs inALGOLare separatedintoblocks , withsmaller called-subroutines or procedures.APLIn 1960, Ken Iversonof IBMdevelopedAPL(APro-gramming Language) as a notation for describing algo-rithms. (An algorithmis a prescribed set of well-definedrules or proce ssesfor thesolution of aproblemin afinitenumber ofsteps.) Basedonaseriesofsymbols forlogicaland mathematical functions , APL is easy to learn andrequires relativelyfewcharacterstodefinecomplexoper-ations. It is used inapplications rangingfromcomplexmathematical and scientific problems totext editingandcomputer-assisted education.APL's major attractionis itspowerful problem-solvingcapability coupled with ahigh degreeof interactivity . Thisallows top-level managers, such as businessmen and financialanalysts with key decisions to make, to " have a con-ference" withtheircomputersusingAPL. Sincethelan-guageis easyto learnanduse, thesebusymanagers do notrequire extensive training nor added staff to handle theprogram.APLmakes useofseveral unusual symbols, suchas anupside-down T, and thus special terminalsarerequiredforAPLtoput these symbolsintothemachine. APLisnot ascientificlanguage, but is consideredmoreof a manipu-lative language for handling longstrings of numbers orletters; it' sideal fortext editing. Thetext of an articleorabook canbefedintoacomputer usinganAPLprogram;the manuscript can be rewrittenor altered withspellingcorrections or hyphenation, andthen retrieved fromthecomputer in its newformat. Many modern automatedprintingandpublishingfirms useAPLforsuchautomatictypesetting applications.APL, as well as BASIC, arelanguagesbasedoninter-preters rather than compilers. This means that programscanbewritten, testedanddebugged rapidly.The APLlanguageisusedbylargefirms asapowerfulanalytic tool forlong-rangeplanning.BASICBASIC, Beginner's All-Purpose Symbolic InstructionCode, was developedat DartmouthCollegein1965 asalanguage for introducing students to computer science.Theproject was supportedbyagrant fromthe NationalScience Foundation and was managed by ProfessorsKemeny and Kurtz. BASICwas originallyintended foruseona time-sharing computer.The objectof theproject wastocomeup with aneasy-to-use computer language;its success has made it the mostpopular language among non-professional programmersand computerhobbyists . It isalanguageintendedforanamateur programmer who has a problem, wants to useacomputer tosolveit, wishestoprepare his ownprogramrather than hire aprogrammer, anddoesn't have alargebudget.Amajor advantage of BASIC(and APL) over otherlanguagesis itsuseof aninterpreterrather thancompiler.Programsprepared by anamateur canbeinspected, modi-fied , debugged and corrected without tedious recompil-ation. BASIC can accept program changes with a minimumofeffort onthe part ofthe programmer. Another advan-tage of BASICis its interactivity.BASICis easytolearnbecause it hasalimitedvocabu-lary comparedto FORTRAN, COBOLor other popularlanguages. The primary statements are arithmetic , pro-gramcontrol and input/output. Every language consistsofa set of characters; BASICuses the 26 lettersofthealphabet,all ten decimal digits (0 to 9), and fewer than twodozenadditional characters(arithmeticoperators, punctu-ation, etc .).Herearesomeof thefundamental rulesthat were estab-lishedin theoriginal DartmouthBASIC: A linecaninc ludeonlyonestatement. Eachstatement must includealine number followedbya keyword. Statementsor inst ruct ionsareperformedinorderofoosrnm:D(0(Xla81InApplesoft theGETstatement wouldbe used like this:TABLE3-HEX&BINARYRepresenta-tions of 8080 "addition" machine code:BASICwill not runwhentranscribedintoamachinethatuses another BASIC. First andforemost isthe fact thatsome BASIC's have commands that others haven't. Thereasonfor this isoftenrelatedtotheamount ofmemoryavailable. For example, oneof the first BASIC'savailablefor home computers was known as Tiny BASIC. In itsoriginal form, Tiny BASIChadno stringcapability andcould not handle trigonometricfunctions. Some versionsof it onlyworkedwithintegers andnofloating-point cal-culations were possible. These early versions generallyneeded only I or 2Kof memory. But, as memory gotcheaper, functions were added to these Tiny BASIC'sand programswrittenwiththe updated versionswerein-compatible with theearlier ones .Today, there are still more variations of BASIC. Thefirst distinction is between integer BASICand floating-point BASIC. Integer BASICis generallyfaster, and isgood for videographicsapplications. Acomputer that of-fers bothinteger andfloating-point BASIC's istheAppleII, and the incompatibilitybetween the twolanguages isclearly demonstrated when one tries to run an integerBASICprograminthefloating-point mode. For example,INPUT statements in floating-point are followed by a semi-colon, while in integer BASIC, they are followedby acomma. Stringsarehandleddifferently, too. Integer BASICsimply has no string functions (e.g. RIGHT$, LEFT$MID$, STR$, etc.). These functions are present intheApple floating-point BASIC, and, are similar to thoseusedbyNorth Starbasic.Another thingthat makes BASIC's incompatibleistheway theyuse abbreviations. TheMicrosoft BASIC's usea "T"asanabbreviationfor thePRINT statement. NorthStarBASICuses a "!"andRadioShackLevel I BASICuses "P."Not allversions oftheselanguages convert theabbreviatedformbacktothefull wordwhentheprogramislisted, sothat tryingtotranscribeaprogram with theseabbreviations for anoncompatiblemachinecouldbequitedisastrous.If you stick to usingthe full word andavoidabbrevi-ations, you'll findthat there isasubset of BASICcom-mands that iscommontoalmost all personal computers.Table4containsalistof 41 commands that arefairly uni-versal. However, even though a command mayexist intwo different BASIC's, it maynot dothesame thinginboth. Anexample of thisistheGETcommand. In Apple-soft BASICthis commandtells the computer to wait forthe user to input data fromthekeyboard. Thecomputerwaits for akeytobepressedandthen returns thevalueof that key. InPETBASIC, whentheGETcommandisencountered, thecomputeralsolooksat thekeyboardforakey closure. However, ifnokeyispressed, itimmedi-atelyreturns thevalue255 insteadof just waiting for a keytobe pressed. This means thatprograms must bewrittena little differently for eachcase, as illustratedbelow:A=2+3WRITEHJ FORMAT (12)ENDTABLE 5-ADDITION of twonumbers In FORTRAN:Hex BinaryAF 10H'J11113E02 0603 011111l1ll1ll11l1180 111l1ll1llr.J11I1Ilr.J21 011l1r.Jr.J11Ir.J188 1r.Jr.J11l1r.J11l11l13 111111011111111177 il11111l11110 REM A SIMPLEADDITION PROGRAM20 READ A, B30LETX= A+B40 PRINT X50DATA 2, 360 ENDlinenumber. ABASICprogrammust becompleted with an ENDstatement.A keyword indicatesthe type of instruction such as LET,PRINT, DATA, END, ORREM. REM(for REMARK)isacommenttoinform or remindtheuserof theprogramcontent but is not acted onbythecomputer. LETtakestheformofLETX= A +B +Cwhere LETmeansthevalue of the expression A + B + C replaces the variable X.PRINT, appearing by itself, simply allows a line to beskippedontheprinter ordisplaydevice;PRINT, followedby words enclosed in quotation marks, commands the com-puter to display the words. For example, PRINT "THE SKYIS CLEAR" would result in THE SKY IS CLEAR being dis-played or printedout. The instructionREADorders thecomputer to obtain data fromwithin theprogram andstoreit inaparticularmemorylocation. TheREAD andDATAinstructions are used together in this manner : the firstvariablelistedintheREADstatementcorrespondstothefirst number in theDATA statement. A simple BASIC pro-gramto add2 plus 3 will demonstrate and clarify how thesestatementsrelate:TABLE 2The REMcomment allows usto identifythe programcontent. TheREADinstructionsendsthecomputer totheDATAstoragewherethefirst variable, A,correspondsto2andthe secondvariable, B, hasavalueof3. TheLETstatementmeans that theexpressionA+B or 2 +3 or5replaces X. ThenthePRINTinstructiondirects thevalueof 5to be displayedonthe output. The ENDstatementconcludes the program. For comparison purposes, thesameproblemlistedin Table2 is given again in binaryandhexadecimal machine code for an8080-based computerinTable3.There are quiteanumber ofversionsof BASICavail-en able today with no two types exactly interchangeable. Thus a BASIC programwrittenfor an Apple computero won't necessarily work on a Radio Shack TRS-80. Theg: programsaresimilar enoughsothat evenanamateur can understandthe differences; but the lackofconformityisuJ frustratingwhentheprogram for one computer is wanted to6 runon another andextensive reprogramming is required.15 ming is required. Thereareseveral reasonswhyprogramswrittenin one82ttl GET A$To get thesame action(without having the computer returnthevalue255) in PETBASIC you'dhave to write:I ~ GET A$:IF A$=""THENI ~This isaperfect example ofhowtwoBASIC' shavingthesamecommands can result in programs that areincom-patible with eachother.TABLE 4ABS AND ASC ATN CHR$ COSDATA DEF DIM END EXP FNFOR FRE GET GOSUB GOTO IFINPUTINT LET LI ST LOG NEW(orSCR)NEXT NOT OR PEEK POKE PRINTREAD REM RESTORERETURN RND SINSTEP TAB TAN THEN TOAssuming that the BASIC's dohave compatiblecom-mands . you're still not out of the woods. The reasonisthat somecommandslinkBASICtomachinelanguage orspecific memory locations; notably PEEKand POKE.These commands are available inmost BASIC' s exceptthose from Texas Instruments and Hewlett-Packard.However. because different computers have organizedthe use of memory differently. it is not always possibleto use programs that have PEEKandPOKEstatementsinthemdirectly. For example . if the POKEstatement isused to temporarilystore a number inmemoryfor lateruseonone machinewecouldbeinserioustroubleusingit inanother. IntheApple. memorylocations around768areavailable foruse by theprogrammer , while in the TRS-80 thisarea of memoryis used by the operating system. Sobefore usingthese commands, besureyouknowalittlebit about how bothyour computer and the one the programwaswritten on are organized.Finally, different computers haveadditional commandsdesigned specificallyfor their own hardware configuration.The Apple-II forexamplehasseveral commands. designedto be used inits low-and high-resolutioncolor graphicsmodes, that would be meaningless onanother machine.FORTRANOneof theearliest and still very widely used. high-level,problem-oriented languagesis FORTRAN (Formula Trans-lation). Developed in themid-1950'sbya group of severalfirms headed by JimBackus of IBM. FORTRANtookthree years of effortinvolving some 25.000 lines of detailedmachineinstructions.FORTRAN is always compiled, never interpreted.FORTRANcompilers are available for just about anycomputer manufactured in theworld.Asits nameimplies. it wasintendedforuseonmathe-matical andscientificformulas. However. itsapplicationsbecame more diversedue toits earlyacceptanceat col-leges and universities where computers were introducedtothestudent body. As graduates with knowledge of com-puters andtheFORTRANlanguage wentinto the businessworld . they proceeded to solve business problems withvariations of FORTRAN.Inasteady. evolutionarymanner, FORTRANhasbeenexpanded into an extremely powerful language and itsname has beenmodifiedtoFORTRANI, FORTRANII,FORTRANIVandFORTRAN77. A high degreeof stan-dardizationhas takenplaceover the years sothat apro-gramwritteninFORTRANIV will perform properlywithmost FORTRAN IV compilers.FORTRAN. althoughgearedfor complexmathematicalassignments. is rather st raightforward in its approach .For example, to solve X= A + B when A= 3 andB= 5.the instructionswouldreadA= 3. B= 5. C= A +B.STOP. Thesesource instructions would. in tum. betrans-latedbythe FORTRANcompiler intomachinelanguagetoexecutethesteptosolvetheproblem. Anactual FOR-TRANprogramislistedin Table 5. Thisprogramis iden-tical totheBASIC program listed in Table 2.Acompiler tohandleaFORTRANIVlanguage is quiteextensive. Not onlymust it handle aconsiderablenumberof mathematical operations,but it mustperform such mathfunctions as trig, square roots, exponentials, complexnumbers. andlogarithms. It must also manage to cope withstrings of numbers andlette rs andlengthymathematicalarrays.InFORTRAN, anumber canberepresentedasa fixedpoint or asafloating point. A fixed-pointnumbermust bean integeror wholenumber andcanbepositiveor nega-tive. Afloating-point number is similar toscientificnota-tionwhere "number"may be expressed as anumber fromI to 10multiplied by some power of ten; 580couldbeexpressed as5.8x IOl. A floating-point number always in-cludes a decimalpoint; a fixed-point number does not.FORTRANincludes provision for two other types ofnumbers: constants and variables. Aconstant maintainsthesame value during theprogram executionwhile a vari-ablecanbe assigned different numericalvalues while com-putations are beingperformed. The name assigned toavariablecanincludeuptosixcharactersandisselected,wherepossible. by the programmer forhis easein remem-beringits meaning. Forexample. SQRTFsignifies squareroot.The basic mathemat ical symbolsfor FORTRANoper-ationsare:Addition +Subtraction-Multiplication *Exponential**Division/Forexample, toindicate2 raisedtothe3rd power , weuse2**3. As with standardmath notation, parenthesisareusedforgroupings; For example: (2 +3) raisedto the3rdpower is writtenas: (2 + 3)**3.Input-output statements in FORTRANare expressedas READ, WRITE, PRINT, PUNCHandFORMAT(thisdescribeshow the output information should be accepted).AGOTOstatement informs thecomputertoexecute aninstructionor statement otherthanthe next statement insequence.An IF statement provides for a conditional trans-fer of control, orproceedtoanotherstatement if specificconditionsare met. AnENDstatement informsthecom-piler that theprogramis completed.COBOLCOBOL (Common Business Oriented Language) wasdevelopedin1960 by theDepartment ofDefensetogetherwith users and manufacturers of computers. Its purposewas tohandle relativelylargevolumesofbusiness infor-mation for rather simple applications . The intent was toenablenon-programmerssuchasaccountantsandclericalstaffto express their business problems inEnglish. Forexample. if a clerk wants to know the value of present stockin inventory. theCOBOL statement would request " COM-PUTESTOCKVALUE." leaving nodoubt ofthemean-ingto the human. ACOBOLcompiler inthe computerwould convert the statement to the necessary machine-languageinstructions requiredtoinitiate the actions.Thebasic COBOLvocabulary consists of 250 key words;additional words can be created merely by specifyingnamesfor dataand instructions.Scientific applications generallyrequire complexstepsand considerable calculations. but have fewinput andoutput demands. Businessapplications, on the other hand.demandconsiderable input and output with relativelylittlecomputation. COBOL is designed to handle extensivefiling onpunched cards,tapes or magnetic disks.oCDm:D...-(.)zUJ::JoUJa:u..tothe " E" through "1"outputs, andthe single wire from the wiper to "IN,"Thiswiringisshownin moredetailinFig. 6. Next, the LED may be installed.Finally, wire up pot R25, the outputconnectors, and the power leads. Don'tforget torunashort wire fromthe cir-cuit -board ground foil to the box. Agood place for this isat the "minus"terminalof CII (220 IlF) . Wireup therowanjackJt(on the back of the box)andyou arefinished.Television viewerswantlowpower consumptionMore than si x out of tenTV viewers believedthat reduced power consumpt ion would bea" veryusef ul feature" in a recentnat ion-widesurvey carri ed out by Venture DevelopmentCorp.. aWellesley. MA, market-r esearchf irm.Prospectivebuyers wo uldbe wi llingtopay upto$41 addit ional forsignif icant energy-savi ngfeat ures. Runner-up. with j ust about 60 percentof t hesurveyees. isbetter sound qual ity, andTV li steners feel t hat better speakers wouldj ustify a $66 incr ease on the pr ice oftheir sets.Stereosound . however, wouldbeworth$80.About 40percent oftheviewersfelt that auto-mat ic t uning through the use of vert ical intervalreferencewou ldbe" very useful ," and 25 per-cent opted for pushbuttonchannel select ions.(Inviewof the lowpower consumpt ion ofmodernTVsets.it might beinterestingtoin-vestigate howmuch of theresponset othatquestion is due to consumer ignorance and t hepr esent campaig ns forenergy economy.)Special featuresmarknew video disc playerTheSelectaVis/onvideodiscplayer, a prod-uctof RCA. wi ll comewit htwofeaturesinitslatestdesignthat cangreatlyi ncrease its use-ful ness tothehome viewer.Visual Searchallows the viewer toscan theprogramat manyt imesnormal speed-eitherforwardor backward-while continuouslydis-playing a pictu re on theTVscreen. RapidAccess locates- at highspeed-any desiredsegment on t he disc . It uses a digital time indi-cator. (RCA had previously demonstrated amechanical t ime indicator.)The first VideoDisc players will be mono-phonic . since the users will be owners ofpresent-day TV receivers, all of which aremono. Ster eoversionswi ll comelater.RCA expects tohave t he fi rstplayers onthemarket i n t he fi rst quarter of 1981. Theagree-mentsthat havebeenreachedwithCBSandZeni th are expected to result in those two firmsenteringt he vi deo discbusiness with productsbasedontheRCA capacitancesystem.oodCDm:ccoCDo91

Assembling the LegsPart 3-Every robot should have away to get from placeto place. This part of theUnicorn-One series describesthemobility base, which allows the robotto do just that.JAMES A. GUPTON, JR.(J)aZoa:I-aw....JW6o

a:92HAVING ALREADY OUTLINED THE CON-struction of therobot's arms and hands inparts I and 2of this series, we'll nowdiscuss its mobility base-the poweredsectionthat allowsittomove fromplaceto place.The mobility base houses the robot'selectrical power source, its drivemotors,and theheart of its wiring system.Whileitmay benecessaryto purchasesomeofthecomponentsofthemobilitybase new, there is still a lot of money thatcanbesavedthroughjudicious scroung-ing. Remember-it doesn'treally matterwhat youusetoget somethingdone, aslongas it doesget doneandthe resultsarewhat you need.We'll present twoapproaches tocon-structingthemechanismofthemobilitybase. Thefirst ,whichmayrequiresomecash outl ay, is the one we've found to givethe best result s. The second, which ismore economical, is a bittrickier andnotquite as acceptable to the purist. Still,bothwork.Figure 19 illustrates the dimensionsand external appearance of Uni corn-One's mobilit y base. Actually, for thesake of economy, the original housing wasmadeusingalargediscardedelect ronicchassis, as seen inFig. 20.One of themost stylish ways to go is touseBud aluminum or steelpanels, platesand frame sections, which can be orderedthrough most electronics parts distribu-tors. The partslist shows the designationsof theBud partsrequired. Unfortunately,this approach, which requires only a littlecuttinganddrilling , canturn out tobefairly costl y.Youmight, therefore, want toturn toscrounging (a local sheet metal firmmight have some odds and ends thatcouldbe pickedupcheaply), orpurchas-ing material that was notprecut. Be sure,though, that the aluminum (if that's whatyou'reusing)is type 5005-an indicationof its strength. Youmust bear inmindthe fact that the mobility base will besupporting at least 30 pounds of therobot'sweight andthat if it is tooweak,themechanical integrity of therobotwillsuffer.Everypart of the mobilit ybase skincanbemadefromaluminum, except forthe top. That should befabricatedfrom0.125-inch steel, both to support theweight of thebody and to allow thebear-ingsuponwhichthebodywill rotate toturnfreel y.The side panels can be made from.0625-inch aluminum, since they will notbe responsibl e for bearing weight. Anoptionis given in the part s list to use four19 X7-inch side panels. These are not, ofcourse, thedimensions shown inFig. 19,but reflect thepossibilityof yourchoos-ingtobuildasquare base, andalsotheuse of a smaller size batt ery. Actually, thedimensions are not criti cal. Just makesure that the robot' s center of gravit y fallswithin the support points (the wheels)andthat thereis enoughroominside themobility base for thebattery, motorsand, terminalstrip. Be sureto allow sufficientclearancefor you to access thebattery.Fin all y, aluminum angle-bracket ,availableat hardwareor building-suppl ystores, will do very nicely for the frame inplace of moreexpensive materials .Access to themobility base is providedby ahinged plateat theback(Fig. 21).Layout the interior so that the importantparts can be reached through the openingthisplateprovides. Use the diagrams andphotographsinthis installment toguideyour thinking. Thereisnothing forcingyou to make a carbon copy of the originalUnicorn-One. Useyourimaginationandingenuity.A2' j,-inchwidecurvedopening willhave tobecut inthetop of the mobilit ybase(refertoFig. 19) to permit wires tobe routed between thebase and the body.Thi s opening may be located at either thefront ortherearof thetop section.Youshouldmake surethat thewires will notjam in the slot as the body rotates---don'tforget to allow slack in thewires for thispurpose- and the slot shouldbeedgedwithsomesoft materi al suchas severallayers of electrical tape, or flexible tubingwhich has been slit tofit over the cutmetal, to prevent chafingof the wires'insulat ion.Transmission anddrivetrainThereare thr eemainsections tothe"mobility" part of the mobilit y base.Theyare themotor s, thewheels, and thepart s which tr ansmit the action of theformer tothe latter. Thewheels are easytoobtain . The two6-inchdrivenwheelscan come from an abandoned child' s wag-\//1- - -1FIG. 19-MOBILITY BASElayout anddimensions. Figures here are for author's prototype-yours maydiffer(see text). Toppl atei s made of steel ; rest can bealuminum.FIG. 20-EARLYVERSIONof themobilitybaseenclosure, buill fromparts at hand.FIG. 21-HINGEDBACKPANELall ows accesstocomponents mounted inside mobilitybase.on orscoot er, orfroma lawnmower ser -vice shop, to namea fewsources. Thefrontcaster wheel is probabl y best foundin a hardwar e store .The preferredmotors,used in thefirstapproach, are gearmotors whichrunat aspeed of between 20 and 25 RPM.Sourcesfor a 22 RPMmotor are given inthe parts list. If you elect to go the secondroute, you canuse simpler,higher-speedmotors. Again, refer to theparts list.Figure 22 illustrates a section of amobility baseconstructed using the 22RP M gear motors. The motor is very eas-ily attached to the frame of the basethrough the useof an alumin umanglebracket at the bott omand two 'I. -inchODspacers at the top. Attachment ismade using the existingmotor mounti ng-holes. By using counter-sunk flat -headmachinescrews, the exterior of themo-bilitybaseisleft freeofprotru sions andcan be paint ed withoutfurt her -fi nishing.Thewheels, whichusuallycomewith'I.-inchshafts, are coupledtothe 'I.-inchmotor shaft by means of a 2.5-inchlong,'h -inch spacer, with an inside diameter of'I.-i nch, securedtoboththe axle andtheshaft bymeans of set screws. Alterna-tivel y, a .374-inchODcoupl er may beusedandtheshaft and axle securedtoitwith dowel pins. Refer to Fig. 23 fordetails.Two motor/w heel assemblies areused,oneoneachside. Front support is givenby a castered wheel locat ed atthe front ofthe assembly. Steering is accomplishedby driving only one motor,using the oth-FIG. 22-0NE OF THE TWO gear motors used todrivethemobility base'swheels.er as a pivot about which therobot turns.Or, for speed, onewheel mayberuninone direction while the other is run in theot her.Thealternate methodfor drivingthemobility base, illustra tedinFig. 24, usesless expensive, but much faster-turningelectr ic motors coupled to the wheelsthrough a set of wormgears. This met h-od, while less expensive in terms of mate-rials, requiresalot of painstaki nglaborandprobablythe use of awell-equippedmachine shop. It is presentedheremostlyas an exercise in developing alternateways to achievethe same result s.The motor is mounted on a 'I.-inchthickaluminumplate which, inturn, ismountedontheinsideof thebott omofthe mobility base using fourspacers. Theshaft of the motor prot ru des downoo--1oOJm:Il--CD0>o93HEIGHT WILL VARYWITH WHEEL SIZE. \.75ALUMINUM ANGLEMOTORSUPPORTII(@J 1lTIDTO CLEARAXLECOUPLER J--f=- 2.38 2.59 3.252.00(TAP8- 32)----- -3.00-- - ---.251:-------2.504.25f-- .30 1==:::::O::========:=:::::O:: 1i +==1=rT\. . 1 .1NOTE:DRILL LAYOUT FOR MOUNTINGGEARMOTOR BASEDON.125 MOBILITY BASE SIDETHICKNESS 4USE NO. 19DRILL 2.50-----1(0.166) ...COUNTERSINK FOR FLAT HEADSCREWUSENO. 36 ORILLTOTAP632 ORORILLTHROUGHCOUPLER AND.2497 SHAFTWITH .9625 DRILL FO R---->ooJ-----..1 \... +DOWEL PIN .50 ,----.375 .-t-;;.m;-::-;--,I. 2.50 .!---r- T.50 FORSET SCREWWHEEL AXLECOUPLER .375FORLOCKPINALL DIMENSIONS IN INCHESFIG. 23-MECHANICALDETAILS of 22-RPMgear-motor mounting. Some di mensions may changeifsi zesof wheel orwheel-shaft you use differ f romthose usedbyauthor. .PARTS LISTSupplier's Supplier'sItem Size Quantity part no. Supplier It em Size Quantity part no. SupplierSheet metal . 125 x10.5 x19 2 PA-1 106 ,@ or(type 5005) inches (5005alum.)3-amp split- 2 61.085aluminumphase.125x10.5 x 2 PA-1 106.@15.75 inches Battery lead-acid, 12- local.125x19.5 x PS-1258. @volt. 12 am- supplier15.75 inches (steel)pere-hours.125 x19 x PS-1109.@gelled-elect ro- as see backoflyle. for 12 required Radio-15.75 inches (alum.)volt s. 12 am- Electronics(Optional-for . 125 x19 x 7 4 PA- 1104.@pere-hour suse withmo- inches. Note: (alum.)tor-cycle bat- .0625 sheetsSUPPLIERS:t ery and19- maybe usedThe Robot Mart Inchsquare for sidesif de-base) sired. Room. 111319 W. 34t h 51.Aluminum angle .0625xV. 16 feet Local hard- New York,NY 10001inches waresupply ($3.00 for cat alog)storeor WinfredM. Berg, Inc..125x .75 .125 x .75 in. x 81-2901-3 ,@499 Ocean Avenue3 feetE. Rockaway, NY 11518. 125 x .75in.x 81-2901.@ EdmundScientific Co.12 feet 101 East Gloucester PikeRear panel 1 x12 Inches Local hard-Barrington,NJ 08007hinge waresupplyGl edhill ElectronicsstoreP.O. 80x1644CIJ .Marysville. CA 95901o Wormgear 24-pitch- '1.- 2Zinch bore, 300@BudIndustr ies, Inc.a: teethf-. Partsmay beorderedthroughoWor m Double pitch 2 W24s-4DUJ local electronics supplier..JUJWheelmotors 22RPM gear- 2 715-900153.@6NOTE: Part numbersfor all items wi th " G"shownas supplier areCimotor (Brevel)those usedby Bud.a:94ALL DIMENSIONS ININCHES.11.125 DIA.CUTOUTFORMOTORSHAFTANDWORM--.,.- -IPINBOTHSHAFTS WITH..0625 DOWEL PINS.-------------8.50--------------L T___ 0 1/4" ALUMINUMPLATE 03.50- - - - - +JJ TAP4 _.2497 ID -----.., .25 0 CORNER i";t'SHAFT COLLAR..-HOLES II-----L.---- 108-320r-1.00-l -j.25f- 1-.75-]J c[m--l25f--HANGERSCUT HOUSI NGSCREWS.L . I FROM .250"ALUMINUMPLATE (2) ATTACHMOTOR_. TOMOUNTING - .-- - g , .375ALUMINUMSPACER. PLATE. 1: ...: J LENGTHL VARIESWITH '" 'l l ANOGEARORIVEUSED.--.I- 11 I I ), I I I I I I1---1.50---1 1--1.25-1.374800/.250 ID COUPLER ADAPTERHALFINCH WHEEL AXLETO.2497 SHAFTBLACKREDORANGEGREENYELLOWBLUEWHITEBROWNREDBLUEORANGEGREENWHITEBROWNYELLOWBLACKGREENREDORANGEWHITEYELLOWBROWNBLACKBLUEooo 0o 00 '0BLACKREDORANGE}GREENORANGE}GREENWHITE }BROWNYELLOWREDORANGE}GREENWHITEBLUEYELLOWBLACK }GREENRED }ORANGEGREEN }BLACKORANGE}REDHORN GROUND+ 12VDCLEFTWHEEL MOTORLEFTELBOW MOTORLEFTSHDU LDERMOTORCASSETTEREMOTECONTROLRIGHT HAND SOLENOID12VDCROBOT BODYROTATIONMOTORGROUNDLEFTHAND SOLENOID12VDCROBOT LIGHTS 12VDCLEFTELBOW UPL1MITSWITCHLEFTELBOWUP L1MITSWITCHLEFTELBOW DOWNL1MITSWITCHRIGHT ELBOWUPL1MI TSWITCHRIGHTELBOW DOWNL1MITSWITCHFIG. 24-MORECOMPLEXDRIVE MECHANISMis shown above. Power i s t ransmitt ed towheelsthroughright angles, bymeans of worms.Gearmotor drive issimpl er andmore reliable.FIG. 26-THIRTY-TWOTERMINALbarrier strip(at left)for power di stribution andcontrol. Willf irst beconnectedbycabletocontrol boxandlater directly toRICreceiver or computer.throughthemountingplate andthrougha hole in thebott om plate of themobi lit ybase. Attached to the end of the shaft is adouble pitchworm. This wormmesheswith a 24-pitch, 3D-toot h, wormgear,affixed to t he end of the shaft which con-nectstothe wheel. Ascanbeseenfromthe diagram, several bearings areneededforthismethodandthebearinghangers(theplat eswhichholdthebear ingsandareattac hedtotheframe of thebody)must be very carefull y machined if thingsare to work right. Also shown in thi s dia-gramisanot her coupler, usedtoextendthe lengthof the wheel shaft.While this met hod can be made towork, it is one place where you mightwant to consider splurging and buyingthe gearmotorsto use in the first met hodpresented. Theextra cost will be morethanoffset by the ease of constructionand thefinal result..... we e: :0 :< ::IE5 6 8 9"=' "=' "='RlR2INPUT 470n1.25VFULL "='SCALE+C2JI0pFanother output pinand lightsanotherLED. That results in a bar-graph displaythat draws only 20 rnA while lighting tenLED's, insteadof 200mA for thestan-dardbar-graph configuration. A highersupply voltage is required, however, be-99enoZoa:I-oW..JW6oc(a:100THESEIRE lITHIIE-IIDE TRIIIIII DEIICES.THESE IRE PRIDUCTlllllDElIICRI-SYSTEMS.IIITHER HII ESTUDY SCHIllIFFERSTHEIEICEPT ITS.111111111111111111 11111111111\\\\\\\oo-toCDmJJ....co(X)oI ...'UI...SimulatedTV Reception_NATIONALnll;TECHNICALLII;I SCHOOLSTECHNICAL-T RACE T R A IN IN GS INCE1 SO!5Resi dent andH ome.St udyS c h o o l s4000 SO.FIGUEROAST.. LOS ANGELES,CA. 90037DCheck if interestedin G.!. information.DCheck if interestedONLY in classroomtraining inLos Angeles.Name Age __Address _Apt. City _State Zip -------.----- -----------1 r ~NATIONAL TECHNICALSCHOOLS ~ .4000SouthFigueroaStreet. Dept. 206-100 .............::..1LosAngeles, California 90037Please rushFREE color catalogon course checkedbelowD MicroComputerS/MicroProcessors DAutoMechanicsD Communications Electronics DAir ConditioningDDigital Electronics DHome AppliancesDIndustrial Technology DColorTV servicing~ . _ - - - - - - _ . _ . _ - - - - - - - - - _ .._. ----------IN FACT, NTS ELECTRONICSPROGRAMS INCLUDE THEWIDEST ARRAY OF SOLID-STATEAND DIGITAL EOUIPMENTEVERFFERED BY ANYHOMESTUDY SCNO OBLIGATION. NO SALESMANWILL CALL.APPROVEDFOR VETERAN TRAINING.1. The NTS/HEATH H-89Microcomputer features f loppy disk stor-age,"smart " video terminal, two zaomicroprocessors, 16KRAMmemory, expandable to 48K . Avail abl e inNTS's Master Course inMicrocomput ers.2. The NTS/Rockwell AIM 65 MicrocomputerA single board unitfeatur ing an on-board 20column alphanumeric print er wit h 20character display. A 6502-basedunit4KRAM, expandable.Avail able in NTS's Microprocessor Technology Course.3. The NTS/KIM-lMicrocomputerA single board unit featuri ng a6digit LED display withan on-board 24key hexadecimalcalculator-typekeyboard. A 6502based microcomputer withlKof RAM memory, expandable. Availal;>lein NTS's Master Course inElect roni c and Industrial Technology.Now, for the first time, you canlearn all about micro-computers by working withyour own productionmodel athome. We'llexplaintheprinciples of troubleshooting andtesting this remarkableinstrument and, best of all, we'llshow you how toprogram it to do what you want.It'stheperfect opportunity for you to learn BASIChighlevel language programming andassemblylanguage programming.Then, to learn how tolocal ize microcomputer problemsand solve t hem, you'll experiment and t est witha digital multi-meter and other test ing gear.But mostimportant, you get to assemble and work withtoday'smost sophisticatedmicrocomputers, not home-madetraining devices.We believe this makes learning a lot morerelevant and excit ing.In fact, productio n-model equipmentis featuredin allNTS electronics programs.Our Color TV servicingprogram boasts theNTS/HEATHdigital color TV (25" diagonal) you actually build and keep.In CommunicationsElect ronics you'll buildand keep anNTS/HEATH2-meterFM transceiver, along withdigital multimeter and service trainer.WhicheverNTS elect ronics program you choose, you can count on workingwithmuchthesame kind of equipment you'llencount er in thefield.Find outmore in our f ull color catalogon theprogram of your choice.NTS also offers course in AutoMechanics,Air Conditioning and Home Appliances. Checkcard formore information.103Timers andsequencersUseanLM3915 tomonitor thevolt-age on a discharging capacitor, as in Fig.8, andyou' ve got a simple timer. Eventhoughthecapacitor voltagedecays tozero logarithmically, displaying it viaanLM3915results in equal time steps.Eachtime stepisapproximatelyRI xC1/3.The sequencer showninFig. 9isavariation on that. Capacitor CI ischargedlinearly bythecurrent sourcemade upof QI , LEDII andRI. Whenoutput 10 startstotumon, Q2 and Q3conduct andCI israpidlydischarged.Cycle time is about IOxRI x CI. TheLM3914 outputs couldbe used to driverela ys, opto-isolators, or logic circuit s,forexample.Other ideasDon ' t think the LM3914 and LM3915can dri ve only bars ofLEDs. The LED' scan bearrangedincircles, or as X-Ydispla ys, for instance .LCD' s, vacuumfluore scents, and low-current incandes-cent bulbscanalsobedriven. Astheexamplesshow, out putsmayinterfacewith CMOS, TTL, opto-isolators andrelays for a variety of automaticmeasurement and control functions.The decibel displayof the LM3915isespecially att ractive for audiophiles.Liketheop-amp, applicationsof thosedisplaydriversarelimitedonlybytheimaginati on of the designer. R-ELF35I, that combinelowbiascurrentwith a high slew rate are recommended.Theoffset-adjust pot RIIis adjusted foraO-volt output fromIC4 withno audioinput applied.As that exampleshows , the LED'scanberunfromanunregulated , unfil-tered power supply. The 6.3-volt center-tappedtransformer, and diodes DIandD2, provide a full-wave rectified voltageofabout 4 volts to the LEDanodes. Thatgreatl y reduces theload on the V+ sup-plyinthebar-graphmodeand alsore-duces heat dissipati oninthe LM3915integrat edcircuits.In this circuit, resistor R7sets thereference voltagefor both IC' s. Sinceboth IC' s have identical loading on theirreference outputs, the reference voltagecan be changed (from the 10volts shownhere) bylowering R5 without affectingthe 'LED inten sities. Thetime constantR3-C2 set s the displaydecay-time andcan be optimized by varying the capaci-tanceof C2.It' s very easy to add an alarm that willflash theLED' s when theinput voltageexceeds full scale. Thecircuit is shownin Fig. 7. If desired, that scheme can beusedto flash the display when the inputvoltage exceedsthethresholdof any ofthe ten LED' s, bysimplymovingtheresi stor-capacitor network(madeup ofR2 andCI ) over to a different output oftheIC.R44.7KR5lK.01Rl1R3lKVee+ClIIlFLM3914LM3915R9"17 163 4,..-_-----GRID _ _ """'_U_""-GRID+405V-- +7.0VCRTBIASFIG. 1and blue signals ina common cathoderesistor. Figure I shows that circ uit asfound in many sets. Older sets used a twintr iodeandonetriodesectionof anothertube. Later sets used a special triple-triode,but the circuits wereidentical.Theplatevoltagesofthose tubes con-tr olled the DCvoltages and signals onthe irrespective color gri ds in thepicturetube. So, what happensif youseea one-color problem? Too much red or notenoughred, etc.?Youhave a fault in thestagethat amplifies that color only. Whathappensifyouhave afault insomethingthat affects all three at once?Youhave anupset of all three gridvoltages on thepic-turetube, andin most cases, the gridvolt-ages go too far positive and the rasterflares and getsfartoobr ight !Inonecase, an RCA CTC-25, the ras-ter flared. With theSERVICE switchin theSERVICEposition, thesetuplineswereatleast an inchwide andso bright we didn'tdare leave thesetonformorethana fewseconds for fear of burn ingthe screen!Wehunted aroundandfinally solvedtheproblem. Wehappened to look at thetopofthechassis. Bothofthediffamptubes(6GU7) were dead! Checking the pic-ture-tubegridvoltages we foundthefull+350-volt DCpotential fromthe supplyon each one. Without a heater in t hetubes,theydrew no platecurrent at all.The cause of that was a bad solder jointin a wire jumper on thePCboard, in the6GUTs heatercircuit. In anot her RCAchassis with similar symptoms, thediffer-ence-amplifiertubes weregood. Thebadsolder joint this time wasat oneendofthecommoncathoderesistor. This time,we used the met hod I've been recom-mendingand found the cause far fasterthan we had in the first case. I havesaid-andI say again-always check theDCvoltageson thepict uretube !Since the bias voltage on a picture tubeis always thedifferencebetweenthecath -odeandgridvoltagesanythingtha t hap-pens toeither onecanchange it. Gridscango posit ive or thecathode cango toofar negative . I remember oneset withaflaring raster and blooming . A checkshowedthe cathode voltagesto be almostzero. Since grids were still at + 200 volts,that left themwithahighpositive bias.That wasdue toanopenvideopeakingcoil betweenthevideooutput tubeplateandthepicturetubecathodes. ThehighB+ voltage to the cathodes was fedthroughthiscoil.Some of the early sets use a sort ofZip _elementary brightness-limiter circuit.That is . usually called a BRIGHTNESSRANGE control, and is simplya pot in' serieswiththe main brightnesscontrol.To set thisup correctly, themain bright-ness control is turned alltheway up andt heRANGE control set so thatthe picture is just belowthe point ofbloomi ng, Some recommend settingfor aspecifiedDC -voltagedevelopedacrossatest-point resistor. If the range controlisn't set correctly, it canbepossibletoturn the -rnainbrightness control tothepoint wherethe raster will flare or be fartoobright. Normal symptomof this iswhen the brightness control will not turn .the rasteroff. . To repeat something mentioned re-. cent ly: inthelater RGBsetswithcom-mon grids, theDC bias-voltage is set by aresistance divider. If the ground leg of thedivider opens, the grids go too far positiveand theraster is'too bright.No matter how new or old a TV set is,you' ll find the same basic relationship.between the'grid, cathode, and screenvoltages of the picture tube. And the' sameresults, if anyofthebiaslevels gooff value. So, asI keep saying, develop ahabit of checkingthosevoltages whenev- er yourun intoanykindof brightnessproblem.That can save you one heck of alot or ti!TIC! R-Eservice'questionsSUBFOR 60060 TRANSISTOR/'ve got a WT-509ARCAcathoderaytube tester. Wrote to VIZfor an up-to-datesetupbooklet. Wit h it, they sent anaddendumtothe manual,suggesting re-placingthe39278 transistorwith a 60060.No.w, I can't find this transistor anywhere,and nolistingof itl Doyouknowofasub?-R.F., Chicago,IL.RCAlists a 60060(industrial number)in theirSPG-202XGuide. Theysay thatan SK-3054 will replace it. This is a TO-5cased, highvoltage type,"with flange".AGCBUCKING RESISTORThere's .anAGC probleminthisWest -ingh ouse model CP19A770. I can't get theright vol tages. There' isa keying pulse onthe AGC tube, and a small change on theplate with or without a signal.The pictureis t oodark, andI can't adjust i t.-F.N.,Pewaukee, WN.Your AGevoltages and reactions seemto be OK. ' Suggestion: There's a 15--megohm resistor in a line fromtheAGCtest point overtotheB+255-volt line.Liftone end of thisresistorand checkit..If it is openor has gone way up in value,there won't be enough' '' bucking voltage"tokeeptheAGCfromdrivingitself toofar negative. This cutstheIF gain, whichresultsin a darkpicture. Thisusedto bequitea commonproblemsome timeago;the case you describeis thefirst I've seenfor quite a while.VOLTAGE-REGULATOR PROBLEMSHere's a dandy on in a Panasonic CT-914 (ETA-12) chassis. If you' get onewith a vertical flutterin the picture, don'tconcentrate on the vertical circuits! Itcouldbecausedbythe DCpowersup-ply!CapacitorC808, 1.0 ILF, 160 volts, maybe open. That is in the line fromthebridge-rectifier output to the Trigger-PulseSCR, TR802. Evidently a pulse-shaper inan R-Cnetwork with R804,(56K)to the gateof TR802.If thesetsshuts downinstantlywhenyou put thenew capacitor in,yank it outandcheckfor leakage!Evenanewonecan be bad. Symptoms of that flutter :+IIO-volt DCsupplywill be low, about+107 volts or so, andit will fluctuate .Thanks a lot to Douglas P. Hoff ofVacaville, CAfor that helpful hint.TWOPROBLEMS-ONESET/'ve got a st icky problem inthis Zenith16Z8C50. The highvoltage isupto 31kV,and the high-voltage adjust pot won'tchangeit. Thebrightness control doesvary brightness and thehighvoltage./'vechecked several things inthis circuit. Noluck.I have another odd one. Myvoltme-ter probe slipped while checking thedamper plate, and hit thecathode. Therewasaloud'pop', andnowI read +500volts instead of +390, +310 volts insteadof +250, andI get +1036volts on theBBOVboost. Can you tell me what tocheck from here on?-D.P., Berwyn, IL.Yes, First, check your voltmeterandmake sureit'sOK! That may explain theextra 60 volts. (Ask me how I know? I didthesamething some yearsagoinsameplacewithsameresults!Sixtybucksfornew parts formymeter madememuchmore careful.). Asfor the high-voltage problem, youmentionedthat thevoltage on the6HV5regulator-tubegridis off. That is apt tobethecauseof your high-voltage prob-lem. Check it while turning the high-volt-ageadjust control; seeif it variesas itshould. If not, check all resistors andcapacitorsin thegridcircuit. Thosehavebeenknownto break downunder loadcausing the symptomsyou mentioned.NOREGULATIONON PICTURETUBEWhenI wroteyou originally, you toldme to checktheDCvoltages on thepic-ture tube. (RCA CTC-72 chassis, novoltageregulationonpicturetube, high-voltage wayup. I did; theDC voltage onthe common gridsread normal, buttherewas an open connectionbetween thepic-ture-tube socket andthepin to thegrids!Bit of prying fixedthis and everythingworks.Thanks toR. Jimenezof NJ for thefeedback. R-EIf coupon ismissing, writeHeath Co., Dept. 020-702BentonHarbor, MI 49022Sendto: Heathce.,Dept. 020-702BentonHarbor, MI 49022Sendmy freeHeathkit Catalognow.I amnot currently receivingyourcatalog.NameAddress _City State _CL-724ACIRCLE54 ON FREE INFORMATION CARDoo-lo[IIm::D......cocoo125BUILDAMASTERPIECE OF SOU.NDUNICORN1continued frompage95CIRCLE37 ON FREE INFORMATION CARDFIG. 25-MOTORCYCLE BATTERY used topower robot.Seetext for important mountingprecautions.used toholdthebatteryinplace and tosupport its weight, since the plates thatcoverthe mobilitybaseare probablynotstrong enoughtodothis by themselves:Certainprecautions must beobservedwhenusing thistype of battery! ~ s shownin the photograph, the batteryis unen-closed, whichmeans thatthere existsthepossibility of sulphuric acid, thebattery'selectrolyte, spillingonthe aluminumorsteel of the mobility base. You do notwant this tohappen! Thebatteryshouldbe(andis, inlater versions of therobot)enclosedin anacid-proof plastic contain-er tocontainanypossible leaksor drips.This container shouldalsohave asmallvent, or vents, at the top to permit thehydrogen gas which is generated whenthebatteryischarging, toescape. Thesevents shouldbeledtotheoutside ofthemobilitybase, toallowthe gastoescapedirectly tothe air.There is anothertype ofbattery whichmight be considered for powering therobot. That uses agelled-electrolyteandis, intheory,lesshazardous. Newbatter-iesof this typearemore expensivethanlead-acid batteries, but several advertisersat the back of Radio-Electronics have sur-plusgelled-electrolyte available, andtheymaysuit your purpose.Whatever power sourceyouuse, takeprecautions so that it cannot harm, direct-ly orindirectly, theinnards of therobot.Leads are run from the battery to a32-position barrier strip (see Fig. 26)which is also mounted insidethemobilitybase. Power for therobot's various mo-tors and control circuitryisobtainedbyrunning jumpers fromthe +12 VDC andground terminals to those connected tothe points tobe powered.Note theuse ofcolor-coding in order to make circuittracing easier.Several terminals have been allocatedfor functionsthat havenot yet beendis-cussed. Don't worry-we'll get tothem.Inthe next installment of this series,plans for therobot's bodywill begiven,along with an option or two previouslyhinted at. R-EWersi Organs&Kit sDept. 2114104E. FirestoneBlvd .Santa FeSpri ngs . CA90670Want to cut outa career as atwo-way radiotechnician?MT I offerstheonIy tra ining forprofessional FM two-way radioava ilab le. Qua lified technic iansareemp loyed ingovernment , in-dustry, and publ ic service . Buttraining is your key.Youco uldcut out acareer asa t wo-way rad io techni ci an bycutting out this co upon . We' llsendyouinformationonhow youcan learn more about this spe-cialized field, at home.Name _Address _City _State/Zip --- -----B3KIMTIIMobile TrainingInstitute@WER51Box 735,Camp HIII,PA 17011'lJ.S.A....- --------- --CIRCLE59 ON FREE INFORMATION CARDr------------Wersi Electronics , Inc.Dept. 211720HempsteadRoadLancaster , PA17601Encl osedis $6.00for my Demo-Package (LP with104-pagecolor cata log.)percussion andsustain. Wersi's famousstringorchestraandbass guitar. Exclu-siveSoundComputer for 32-128"OneStopSounds" (t ot al organ presets).Transposer. Andlots more.Buildyourownmasterpieceofsound. No technical knowledge re-quired. Just follow the clearlyillus-trated, easy to underst and instructions.Step bystep. Choose fromat least 10models, (Also fact ory assembled.)Send $6.00 with coupon for your 'hIersiDemo-Package(LP with 104-page colorcatalog).Name _Address' _City State Zip __&_------------------------1FREECATALOG128-pages of hard-to-findprecisiontools . Alsocon-taines 5 pages of useful"Too l Tips"toaidintoolselection. Send for yourfreecopytoday!'hIersi hascombinedselect featuresofthe electronicmusic field, addedits owncreations andyears of research by topengineersandmusicians, toproduceanincomparable line of organs.Space-age technology. True-to-life voic-ing with fulldrawbar system. PolyphonicJENSEN TOOLsINC.1230S. PRIEST DR. TEmpe. AZ. 85281CIRCLE27 ON FREE INFORMATION CARDTHEMEANLITTLEKITNewcompact 24-piecekit of electronictools for engineers, scientists, technicians,students, executives. Includes 7 sizesscrewdrivers, adjustable wrench, 2 pairpliers. wire stripper, knife, alignment tool,stainlessrule. hex-key set, scissors, 2 flexi-ble files, burnisher, miniaturesolderingiron, solder aid, coil of solder and de-soldering braid. Highest qualitypaddedzippercase, 6 x 9 x 13/4 inside. Satisfactionguaranteed. Send check, companypur-chaseorder or chargeVisa/BankAmeri-card or Mastercharge . We pay the shippingcharges.JTK6 Tool Kit $78.00(f)oZoex::I-oW...JWoo-cex::1268085ACOOKBO>OKBasi cconcepts. system control. memory systems andtypes, Inter faci ng, chips. You designseveral completelyoperational B085A-based microcomputers No. 21447 $10.508080/8085 SOFTWARE DESIGNAdetailedapproachtoassemblylanguagepr ogrammin g for 8080 or 8OB5- based computers. Including complete, testedprograms. No. 21541 $9.50TRS-80INTERFACINGUse basiclanguage to control external devices andsense external events. Level IIbasicand4K availablememoryrequired.No. 21633 $S.958085MICROPROCESSORKIT -=--.ij

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The product line includes a largeselection ofDIP converters, plus data-acqu isitionsystems, Instrumentation amplifiers, program-mablegainamplifiers, t rackandhold amplifiersandanalogI/Oboards. Italsoinc ludesa tutorialon track andholdamplifiers, a high reliabili ty pro-cessingsectionand aquick selectiongUidefordeslgners.-MicroNetworksCo., 324ClarkSt.,Worcester, MA01606.CIRCLE 145 ON FREE INFORMATION CARDNEW LITcontinued frompage 114CIRCLE6 ON FREE INFORMATION CARDSEND FOROUR FREE8-PAGE CATALOGoKIT 0COOKBOOK 0SOFTWAREDESIGNNAMEoVISA 0 MSTCDEXP.o TRS-80INTERFACINGFOR EACH:14905NE140TH. DEPT. RElO.REDMOND. WA98052 (206883-9200)Add $2.50postage and handling.SIGNATURECITY.STATE. ZIPCARDNO.ADDRESSENCLOSED ISsUSEYOURCARDREADERSERVICE\CONNECTORCATALOG, MolexFull LineCata-logNo. 800, 228 pages , contains detailsof allproductsincludingfeatures, specifications,pho-tos , drawings, ordering information and cross-referencematerial. 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JAMESWALTERTESTEQUIPMENT, 2697Nickel, SanPablo, CA 94806CONCORDCOmpUTERcomponEnTS1971SOUTH STATECOLLEGE ANAHEIM, CA. 92806VISAMASHRCHARGE (714)937 0637 MINIMUM ORDERSIDDD DRMD ADD SlIDfOR fRlNDCDD W.ond " lIo,.d2 .DDD I,p"of,.m,conduCl o" CAL REI ADD6r,APPLEEXPANSION KIT $4750I NCLUDESINSTRUCTI ONS.8212I/o p-ort$29574lS Series74L500 .26 74L5155 1.15174L502 .26 74L5158 .75:74L503 :26 74L5160 .9574L504 .28 74L5161 .8574L508 .28 74L5162 .9574L509 .26 74L5163 1.607'lL510 .26 74L5164 .6574L520 .26 74L5165 .65llG-COLU_ I"ACT _NTU74L521 .26 74L5170 1.75 .-..c:.-H'GHUT ......OMIUK:II:74L522 .26 74L5174 .75 ..'649"_C._._HIl. 0074L526 .49 74L5175 .75 1Z, .... ' r.74L527 .26 74L5190 .75- .--'-- 'b74L530 .28 74L5193 .95..iase2inc4L532 .32 74L5195 .95 ,.74L538 .32 74L5196 .8574L542 .65 74L5221 1.74L548 .78 74L524O 1.65APPLE II Computer4L551 .25 74L5241 1.654L554 .35 74L5243 1.454LS74 .38 74L5244 1.45With full48K of memory! - 4L575 .60 74LS245 2.254L583 .44 74L5253 .95 4L585 .95 74L5257 .954L586 .95 74L5258 .9574L590 .69 74L5259 2.8574L593 .69 74LS279 .44-4L5107 .45 74L5283 1.00- 4L5112 .38 74L5293 1.854L5113 .48 74L5298 1.204L5122 .48 74LS366 .954L5123 .95 74L5367 .554L5126 .69 74L5368 .554L5138 .69 74L5373 1.394L5151 A4 74L5374 1.3974L5153 .44 74L5386 .65EPROMSlRS-SO16 KMemory Add.on$.A9!i... KITWith jumpers andrnstrucuonsCPU CRYSTALSFroq Application price1.00 Mhz 6800 $4.501.8432 MCI4411 4.502.00 G8/TV"". 4.502.01 TV gm' . 2.902.4576 :J4702baud 5.604.00 4004/4040 4.504.194304 8038 5.605.00 mlse.CPU's 4.50 11------..5.0688 Com5016 4.5010.0 miscMPU's 4.5013.0 4.5014.31818 4.5018.0 808018008 5.6022.1184 B080A 5.6027.0 5.6032.0 5.6032.768 $3.85(/)oZoex:I-oW...JWoo -117 is the' ic w-eose solutjonto \ 'ourpowt'rprob lerns, Thr' ' IPDI i i !l.u.l I:J.n f,ltrr. h.. ,1t10 ."rullbrnkrr, t...." ,j' rN I ..ntl " ,trtwrl,.ullfi' ,llumlO, t...l., n.."r' \""",h f.... , ,,,,teM I uurJ,ot .nd ;.hu,h"',lh . 11 .555Timer27MSM5832MICROPROCESSORREALTIMECLOCK/CALENDARGENERAL DESCRIPTIONTHECOHPUTltIKSfiRECOHIItG !TTLVOlTAGEREGULATORSSN7400N . 20 SN7482N 1.05SN7402N .22 SN7492N .50

SN7404N .22 SN7493N SN7408N .24 SN7495N