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Amateur Computer Society newsletter, 1966-1976 PDF

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Preview Amateur Computer Society newsletter, 1966-1976

~NE\vSLETTER a publication of the SOCIETY AMAT~R COMPUT&~ Number 1 August 1966 AND SUBSCRIPTION have printed the letter: Control l~ERSHIP Engineering (June, P 12); QST Although lId hoped to be able (July, p 78); EEE (June, p 142); to send you the ACS Newsletter EDN (July, p 7); and Computer free, the costs of printing Design (August, p 12). and postage are just too high, despite several contributions, The original letter of an unsolicited but highly welcome. nouncement ran this way: Therefore, a combined mem "This is an invitation to your bership and subscription fee readers i'\Tho are amat eUr builders of $3.00 has been establishe~ of digital computers to join the There will be no dues, at ne", Amateur Computer Society, least not in the foreseeable whose main purpose is to exchange future. The number of News information through a newsletter. letter issues you will receive To limit the membership to the will depend on how many join, really serious, the ACS is open and should be at least 8, only to those who are building or probably more. The Newsletter operating a homemade computer will appear about 6 or that can at least perform auto ~very 8 weeks. matic multiplication and diVision. To become a mIe mber of the liThe newsletter will contain Amateur Computer Society and queries from members with prob receive the ACS Newsletter lems, answers prOVided by myself issues that will follow this or qther readers, details of com one, please send $3.00 to puters built by members and by manufacturers, and information on Stephen B. Gray surplus computer hardware, cheap Amateur Computer Society integrated cirCUits, and relevant 219 West 81 St publications. New York, N.Y. 10024 "vTill qualified readers please Those who sent contribu- send me information about their tions are ACS members as of computers, such as word length, nO't'V', and \,1ill have their sub memory Size, clock speed, number scriptions extended to the of instructions, sources of hard full amount of their gifts. ware and schematiCs, present prob lems, and details of clever solu tions to previous problems. The Beginning "If there is enough interest in a The Amateur Computer Society was lower-level it may be pos group~ launched on the afternoon of May sible to form an 'Amateur Comput- 5, 1966, when letters of . er Logic Society, for those who ann~e­ II ment were sent to ten technical want to construct logic circuits and hobby magazines. So far, f1ve and simple com:,guters. 1I The first ':rour magazines printed to all tuture enquirors, the AC.S various parts of the first ,three resume, which was dated July 1, paragraphs. Only Computer Design 1966, is reprinted here, in part: printed the entire letter, so the great majority of responses were "The main reason for the existence from a rather high caliber of of the ACS is to enable amateur amateur. computer builders to help each other, saving time and money by Response trading ideas. And there are many areas where an amateur needs help: As of today1s mail, 54 letters al'ld telephone calls have been re itA. Circuits ceived, from 19 states, including Hawaii, plus Canada and Switzer 1. Surplus. Where can they be land, and continue to come in at bought? Where do you get the rate of one a day. A third the schematics? How do you came from IEEE members; two are use circuit boards whose Senior Members. Five gave their terminal contacts have been ham call letters. broken off (as all surplus IBM SNS boards tor exam I Most of the prospective ACS ple)? members are in the New York area (19), the Los Angeles area (11), 2. Construction. vlhere can you or the Chicago area (9). Many are find schematics, with parts engineers; several work for com values, for not-too-compli puter manufacturers (IBM, Univac, cated circuits? What are GE, Honeywell) in logic or memory the most practical and design. Two are in highschool. cheapest ways of mounting the components on a board? As only a very few Are homemade printed-wiring eA~ected, are past the half-way mark in the boards cheap enough to use? bUilding of their computers. One man is about two-thirds of the 3. Integrated Circuits. Who way toward completion; the rest makes the cheapest and most are range from "Ilve been thinking reliable IC's? the ~lhat about building a computer for best and cheapest ways of some time" to "I have the shift mounting them? registers completed." liB. Mounting of O'ircuit Boards The most common problems are with input/output, memory, and 1. Fixed. Is there a practical finding overall computer schemat way to do this? ics. This issue of the Newsletter will deal mainly with the problem 2. Plug-In. vJhat female con of the schematics, as this is the nectors are cheap enough to main deterrent to getting started Use in quantity? for most of us. 3. Modular Front Panels. Are First ACS Mailing commercial panels (with jacks) available? What To all those who wrote to types of homemade modular th~ ACS, a two-page resume of the (indiv1dual) panels are plans and aims of the SOCiety was most practical and cheapest?' I ·1 sent. Because this first 1ssue Of 'I II the ACS Newsletter w1ll be sent (Oontinued next page) -.JAlQJSL Number 1 -- August 1966 2 NE\V'SLETTER "C. Interconnections in one ot the following issues. Each issue will also contain prob 1. Fixed. Is fixed wiring lems outlined by members and solu practical? What are the tions turnished by myself (if I most practical ways to use have the answer) or by other mem~ fixed Wiring? bers in later issues. There will also be information on commercial 2. Plugwires. Is it practical ly made computer trainers, which to use plugwires to inter- are usually simple enough to be connect circuits? What built by a computer amateur, if he plugwires, commercial or can get his hands on the schemat homemade, are cheapest and ics. best? 'I'lb.at cheap plug- boards are available? Up.S. As for my own background, I've been an editor and writer on liD. System Design computers for ~ore than 10 years, including five years as the com 1. Overall. \'Jh.ere can comput- puter editor of IIElectron1cs" mag er schematics be obtained? aZine." Can an amateur design his own computer? COMPUTER SCHEMATICS 2. Memory. 'Imat type of mem- ory is cheapest? i1hat is 1. Flodac. The simplest computer the overall cost of a core for which schematics are available memory, per b1t? is the Univac Flodac, which is ac tually a fluid-logic demonstrator. 3. Display. \'Jh.ich is cheapest-1 However, , if you have a good kno'trTl neon or incandescent lamps edge of logic, you should be able vJhat other displays are to convert the tluidics to el.ec economical? tronic logic. If any of you do, please let me know; perhaps we can 4. Out'put. What output is make the electronic schematiCS cheapest and most practi- available to others. cal? Are there cheap tape punches? Is a printer too Flodac has a memory (4 words of expensive? tour bits each), arithmetic regis ter, tunction select, clock, four liD. Help instructions, etc. It's a minimum computer! but contains all the 1. What commercial companies essentia s. are helpful in providing information or surplus Although Univac would not pro parts, or both? vide the schematiCS, the patent gives all the details. Send 50¢ to 2. What companies refuse to the Commissioner of Patents, Ttlash- . give information, such as ington, D.C., and ask tor a copy schematics for surplus of patent 3,190,554, "Pure Fluid components? Comput er , by A. J.. Gehring, Jr. et II ale liThe plan, at present, for the newsletter is to include the By the way, Univac recently above listing ot the basic prob- started to· market fluidics ele lems in the first issue, and then ments, but the prices are rather go into each of the 14 categories steep for an amateur, something' ~NEvISLETTER 3 Number 1 -- August 1966 over $10 for a flip-flop. ferent logic in each a!: ,:.the four stages: NOR, NAND, DCTL and AND 2. Pedagac. Although never built, OR-INV logic. this Upedagogic automatic comput erlJ is thoroughly described 1n Digiac 3050 uses 382 IN60 di three chapters of IIDigital Com odes ($23/100) and 204 transis puter and Control Eng1neering" tors, designated "DE01" on the (R.S. Ledley, McGraw-Hill Book sohematics. These are made to or Co., 1960, 835 pages, $15.50). der for the company, but are di rectly replaoable by 2N404's Pedagac has 19-bit words, 17 ($31/100) • instructions, a magnetiC-drum memory, serial arithmetic and a A schematio is included for single-address scheme. There are the power supply, whioh furnishes six types of circuit cards; the the required±lO volts, and the basic package is an AND-OR (three -17.5 volts. ANDs and one OR), the output of the OR available djrect and in , The Digiac 3050 manuals are verted. $10 for the set of two, one on computer description, the other The basic Pedagac transistor on programming and applications. is a 2N643, which may be obso Digital'Eleotronics Inc., Ames lete, and may be equivalent to a Court, Plainview, New York 11803. 2N395 or 2N397. The basic diode is a DR435 ($80/100), which may (The Digiac 3080 manual, be equivalent to a TI55, IN4009, originally planned as a $50 set lN698, IN9l0, lN91l, IN497 or of two, has finally been publish IN695. The' IN911 seems the clos ed as a single programming manual est match, but this needs for $8. Digiao 3080 is a $19,500 che~k­ ing out. oomputer trainer, desk-size, with 25-bit words, over 100 instruo Pedagac requires about 5,000 tions, 4096-word magnetiC-drum Wire connections. The book gives memory and paper tape I/O, plus a rack layout and a partial wir-' IBM Seleotrio I/O typewriter.) ing table. 4. Bi-Tran Six. This $5500 desk An associate of Dr. Ledley has top oomputer trainer weighs 98 written me that Pedagao has never pounds, has a single-address bi been constructed. It was not de nary parallel scheme, and thirty signed to be built; as its pur instruotions. The core memory pose was pedagogical, the plans oontains 128 6-bit words. Indioa were not ohecked out as thorough tor lamps show the operation of ly as if oonstruotion had been all registers. the goal. It was noted that Peda ~ gao has no real provision for in Volume 1 of the two Technioal put or output. Operations Manuals oovers opera tion;" theory and schematics of 3. Digiac 3050. A $2500 semi individual cirouits. Complete automatic desk-top oomputer parts desoriptions are inoluded, trainer without memory, ·this has except for transformers and core 4-bit words, three registers, in memor.1. The transistors used are: put pushbuttons and output lamps, 2N1304, 2N1305, 2N1309. Diodes: and 7 instructions. lN270. The parallel adder, uses d1t- Volume 2 oovers maintenance Number 1 -- August 1966 4 ~NEWSLETTER programs, w1r1ng d1agrams and log -registers and 64 instruot10ns. io diagrams. However, the 422 has been "de standardized," accord1ng to Uni Pr10e tor both manuals, $29.96; vao, and the manuals are no long Fabr1-Tek Ino., 1019 East Exoelsi-, er available. or Blvd., Hopkins, Minn. 66343. 5. RUssian ENC. Vaouum-tube oom BOOKS AND BOOKLETS puter trainer, this "Eduoational Numerioal Computer" uses 19-b1t We Built Our Own Computers, A.B. words, a single-address system, Bolt, editor. Cambridge Universi and has 11 instruotions. ty Press (New York offioe: 32 East 57 St.), 1966. 101 pages, It also has a magnetio-drum $3.95 hardcover; $1.95 paperbaok. memory of 1,024 words, us1ng a "drum from a maoh1ne of the se This book, reviewed here only r1es Urals-l. Photoeleotrio because several members had asked II tape-reader input, pr1nter out about itl descr1bes very simple put. oomputers, analog and digital, made by 6th-form boys (12 years Seventeen types of 01rouits old) at a British school. are used in ENC total of 387, i inoluding 163 f ip-flops. Main Of use only to beginners and tube types are 6N3P, 6PIP, 6Zh2P, those work1ni with beginners. for those of you w1th aooess to . The digital. oomputers" all use Sov1.et tubes. relays and are quite small. The l68-page English transla ************* tlon of the or1ginal Russ1an (1963) book gives a oomplete dis Integrated Circuit Pro.lects From oussion of very interesting Motorola, available from HEP, ~{Cj to read how the "other s1dell oom Dept. ACS, Box 955, Phoenix, putes. Send $3.00 for "Digital Arizona 85001; $1.10 ($1 ;plus 10~ Computer for Training Purposes for handling and postage). Has 96 (ENC), by V.I. Matov, et al pages, 1s the first IC projeot JPRS: 24,498, OTS 64-31219,i1 to book for the hobbyist and experi Clearing House for Federal Soien menter. Among the contents: a . tifio and Teohnioal Information, square-wave generator with 10- Springf1eld, Virginia 22161. nseo rise time, frequenoies from 6 Hz to 60 kHz; binary oomputer; ********** organ, etc. (Haven't seen it yet but seems well worth the dollar.~ Negotiat10ns are under way with 4 other. manufaoturers to see if ************* they oan sell us sets of overall sohematios, but the outlook isn't Design of Transistor &li tohing good. If you know of other avail Circuits for Data-prooessini able oomputer schematios, let me EqUipment, 75 cents from RC , know and I'll mention them 1n the Electronio Components and De next issue of the ACS Newsletter. vioes, Har,r1son,' N.J. Has 44 pages on des1gn conSiderations, It was hoped that manuals would prooedures and examples, plus be obtainable for the Univao 422 typioal sw1tohing oirou1ts using oomputer trainer, with magnet1o RCA transistors. The 16 o1rouits oore storage, 16-b1t words, n1ne use a variety of transistors and .J.Al.QJSL NEWSLE'l'TER 6 Number l' -- August 1966 voltages; there 1s not a un1f1ed 1-6. oan I buy low-oost inte ~~ere set ot o1rou1ts. The booklet ends grated o1rouits? w1th a oomputer transistor data ohart: 6 memory-driver types, 44 The oheapest ICls I've seen are the logio types, maximum ratings and Fa1roh11d RTL epoxy TO-5 dev1oes, eleotr1cal oharaoter1st1cs 11mits newly reduoed to: tor eaoh. 1-99 100-999 1 OOO up L Buffer $.80 $.54 ,.36 Dual 2- PROBLEMS .AND (SOME) AN SWERS input gat e • 80 • 54 .36 \ihere can I buy computer com JK FF 1.50 1.00 .67 l~l. ponents? Fairoh1ld Sem1oonduotor, 313 Fa1r These have been ment10ned: ohild Dr1ve, View, Ca11f. Moun~a1n John Meshna, 19 Allerton st, Lynn, The Motorola MC700P ser1es'inoludes Mass. 25¢ for catalog. a dual JK flip-flop for $2, 1-999; the Ph1100 E-11ne Series DTL has ALCO, 3 Woloott Ave, Lawrence, a JK FF for $2.80, 100-999. Mass. 1-7. How oan I des1gn a 10-~sec C and H, Paeadena, Calif. delay line us1ng RC elements? Salvage Depts of Autonetios and 1-8. "That are the pros and cons on Hughes Airoraft, in California, serial versus parallel address and Saturday mornings. assool'ated circuit requirements? NOTE: Order by mail only as a 1-9. Where oan I looate aoheap last resort. Word on one store is electroluminesoent output display? that "muoh of the computer eqUipment is pretty junky ••• the YOUR ANS\lTERS TO THESE PROBLEMS ''lILL memory drums seemed beyond re BE PRINTED IN THE NEXT ISSUE. pair ...... Caveat Emptor. ' 1-2. Does anyone have manuals or . THE LAST WORD schematios for the magnet1o-drum system bu1lt by LFE in 1955-6 for That's it for the first issue. As the RCA 501, with a 15-million of today's mail, we have 60 poten bit oapaoity, 120 heads, 100-plus tial members. And the latest word meroury.-wettea relays and what on the poss1b11ity of being able to appears to be two separate ampli buy overall sohematios for a couple f1er chassis? of standard computers is more en oouragingfnow. See the next issue. "wy" 1-3. oan I get IBM SMS ~There oiro ui t oards? NEXT ISSUE will be about input output eqUipment. If you have 1-4. How oan I solve the problem had any experienoe w1th this, or of high-speed, high-power drum··· thoughts to share, send details. head-sw1toh1ng at low cost? 't'Vhat is oheap and reliable? Can we make it? Where oan we get it? 1-5. \'lhat is a sui table connector How muoh of an interface does it tor a 10" x 12" PC board? lid . requ1re? like to use Wire:wrap interoon necttions. Copyright 1966 by Stephen B. Gray . ' Number 1 -- August 1966 6 ~N~SLETTER _Jil.QJiL NEWSLETTER INPUT/OUTPUT ISSUE a pub1loat1on ot the AMATEUR COMPUTER SOCIETY Number 2 October 1966 aeaber wlth much TeletT,Pe ezper1- MEMBERSHIP ence, Jlm Ha7Des, who has analJz~ Inqulrles about AOS membership ed the varlous models ot Telet1Pe have beenr.oelved trom 77 men eqUipment tor us: thus tar, In 23 state., Oanada, Switzerland and Italr. Ot thess, Telline EqUipment 36 have sent in the 13 to become member. (4 have .ent 1n more), Although Teletype gear 1s slow Inc1uding the Oanadian, so the and awJtwarc1 to uae it 1s re841ly ACS Is now an internatlonal. group. avallable and relatlvely oheap. The on17 stutt that ls wlde1, avallable uses the 5-1ev8l Xurr., INPUT/OUTPUT (often called Baudot) eode. manr Although Uhere are a great The old Model 12 has the advan types ot Input/output equipment, tage, tor oomputer use, ot havlng nearly all are beyond the f1nan a para1lel-lnpu1i prlnter and a cial reaoh ot the average amateur, parallel-output ke,board. !hl, ls or the, take up too muoh spaoe. .0 014 lt Is obsol.,. even tor Card readers and punches, magnetio amateur use, bu1i probab17 some ot tape, e1ectrl0 typewriters, elec 'lihe JDaoh1ne. can be obtained from troluminescent panels, printe2s, h ..s In the New York are., whioh crt diap1a, -- these are usuall, was It. ma1ne'.,. too expenslve and most ot them are too big. In the middle ground are !he more recent and more popular such devloes as rear-proJeotlon Kadel 15 is qUite wldely avall display, Nixie tubes, paper tape able (tor example, eee the All readers and punohes, magnetlc tronlos-Hovard ads In QS! maga drums -- expenslve It new, otteD zlne). Thie, llke the rest at the reasonable when used or SUrp1U8. later Teletype line haa the dis That leaves! at the cheap end ot ,advantage tor oomputer U8e ot re the scale, amps and pushbuttons. qUiring eerla1 8ignals. Thus one must bu1ld an eleotronl0 .erlal/ With only lamps and pushbuttons parallel/serlal oonverter, or a8 Input/output, automatl0 pro t1nd an eleotromeohanloal one gram loading Is not p08sib1e, nor (not too hard to tind, partloulap. ls 'he read-ln of euemal data. 11 In New York). Output conslst. ot rea41ng the reglster lamps. the ourrent Kode1 28 11ne i8 U8U- 8117 available! and although ee Tbi. Is well and good for 'he rlal 1n operat on, !s more at first 8tage8 of oomputer bul1ding, tractive tor computer use becauee but 800ner or later the amateur ot Ite hlgher oapabi11t, ~ee4 want8 to get Into automatl0 eper (100 wpa, 10 ohar/sec) and be atlon. Hls t1rst step ls otten 1n oause it 1s more readl1, reooded the direction ot Teletype gear. to a more computer-oompatlble 004e. In tact, one who 18 amb1- !he ACS ls fortunate to have a taus could even oonvert It to a Model 35 whioh uses the ASCII mal11 used tor oommunioation pur code. But probabll it would be poses. Also! the paper tape read easier to keep the 5-1eve1 code er in th1s ine 1s magnet-driven, and just rearrange the numerio whioh makes it nice it one wants oharaoters tor a BCD code. How to use the tape reader by -itself. ever, once one has a program in The punoh is made to be used with and running, he oan oonvert oode the t:yping unit and oannot prao to Murray in the oomputer, so tioally be used alone. that odd-coding would be needed only to get the initial program !hen there is the more rugged Mod in and running. For a serial com el 35 l1ne, but an amateur would puter, th1s might well be done aa not l1kel,. want anT ot this, as in the Raytheon 2501 loading one it is quite a b1t more expensive. b1t for eaoh ot input. (Thls ls used in some SDS and Uni oharao~er vac oomputers, and others.) For 1nformation on the availabil- 1ty ot 26-line equipment, contact It one wants to be a b1t archaio, Bert A. Prall 558 Ridge .Ave., he oould tind out all he wants to W1nnetka, Il11n01s. It one plans know about the Teletype and mag to do his own rebu11ding and re-· net10-wire I/O gear used with pa1r1ng, th1s should be speci SBAC bT contaoting the National tied, as the gear 1s muoh oheaper Bureau ot Standards. Thls 1s, of that way. oourse, completely obsolete by today' s st andards. However, one One oan also get new Teletype might be able to do something in gear from the factory; the Model the W8J ot working over a oheap 33 8-leve1 ASCII machine 1s qu1te tape recorder to get h1gh-s.pee4 popular w1th small oomputer mak operation on the oomputer and ers,and can be had for about slov-8.Peed reoording and plaTbaok .600. Contact Mr. R.R. Bogdan, from Telet7pe gear. Teletype Corp., 5555 Touhy Ave., Skokie, I11in01s. (Nat10nal Bureau ot Standards Cir oular 551, issued Jan. 2~1_1955, Teletype also has punched-tape "Computer Development (S£AO and a'pparatus capable ot higher speed DYSIAC) at the National Bureau of (105 ohar/seo). There 1s very Standards!" was at one time avail 11tt1e ot this on the surplus mar able tor ,2 trom the Supt. ot Doo ket, but Bert Prall 1s the one to uments, Govt. Printing Otfioe.) try. Thls is about all exoept to men Some sav1ng oan be had on the tlon that 1n San Francisco one Teletype equ1pment new from the shoUld trr Buckley's. He usually taotor1.1 by buying the bare-bones has Teletype gear and he once units (liyp1ng un1t, keyboard) had some old IBK Eaeotrewriter separately and doing your own stuff, although the latter was 1n oabinet or cover. The regular key pretty bad condition. But the board has to have the t1P1ng un1 t Eleotrowriter is not at all want to make 1t work. ed by hams whioh should hold 1 t s I price dow. One n10e feature of the 33 line is that the keyboard 1s parallel and P.S. 5-level Murray oode 1s a ~o there 1s an eleotrical parallel/ bit awkward to handle, but then aer1al oonverter. Thus one oan use one could rearrange the Teletype the parallel 1nterfaoe rather than keyboard and the type pallets to the ser1al intertaoe that 1s nor- get his own 5-level oode baaed on Number 2 -- Ootober 1966 2 .JiI.QJSL NEWSLETTER SCD or exoell-3 or whatever la de ',on Drivers aired. But then, ln a maahine ot any size} one oan do the oode oon J1m Harnl. write. that a meat eoo version D1 programming or by mak nomical and .atlstaetor, 41apl&1 ing an otf-line converter) so that is a neon indioator drlver bl a the standard machine .y De used, high-au triode suoh as a 12AX7 or thus preserving the normal ke1- 5965. !he grid ot the tube oan be board arrangement. ~eretore, the 'driven direot trom the UIUal aort major I/O problem is What to do of logio voltages in a tranaiator when Teletype equipment lsn't alat... A 1001 serles re.l.tor at fast enough. the slgnal aouroe prevents the indie.tor-oircult wiring oapaci ***** .....* . ..... tanoe trom 10a41ng the olrcult at all • .Another member, Fred Strother, has turnished the names and addresses One oan get very nloe-lool1ng ot oompanies that aell used Tele neon lndioators enoased in plastl0 type equipmen1;: tor panel mountlng tor around 20 oent. each. Jim puts ten ot the Where to BUl Used TeletYpe GaR 12-volt tubes across the power 11ne so that no fl1ament trans At1ant1c Surplus SellS Oorp. tormer ls needed. An iaolation 250 Columbia Street transtormer oapab1e ot suPp11!ns Brookl11l, New York about 1 ma per lamp ls satistac (oatalog) torr tor the plate supp11. A tull wave brldge reotltier wlthout a J. Thal.en W9IVP fllter is satisfaotorr. 11001 South Pulaski Road Chioago, Il11nois 60655 This arrangement doe sn 't load the olrcuit as a translstor-drlven Alltron10s-Howard Co. indioator would and it 1 s muoh Box 19 oheaper than either a transistor Boston, Massachuaetts 02101 driven lndloator or a 8977 in41- wator tr1ode. It gives a nloe I1l10tt Buchanan W6VPC bright light, and allows the use 1067 Mandana Boulevard ot i80latl, reslstor. to prevent Oakland, Cal1tornia oapaoit1ve oa41ng trom bothering anything. Columbia Eleotroniol (oata10g) 4365 W. Ploo Boulevard With lntegrated'clrcults and low Los Jngeles, Calltornia 90019 voltage translstor logio there are probleas with thl. arrange R.I. Goodheart Co., Inc. ment, however, because the galn Box 1220-.1 ot the trlodes ian' t high enough. Beverly Hl11s, Calltornla 90213 And there il the problem ot all heat trom the tubes. ~at rrea suggest, the Telet7Ped Mi.o del 14: repertorators and tape Beon LamPs tributors, aval1able at a ve1'7 nominal prloe. !he.e unita print Acoording to Pete Showmaa, neon and pertorate 9/161 tape trolD a lampa are oheaper and more etti tive-level ooded .iIDal. !hI kll clent than inoandesoent., an HI-2 board and the tape diatributor ooat1ng lO~ and a 11919 wlth both glnerate the a... 5-level sooket oostlng 32~. However~ oode. there doesn't .eem to be • ~2~, Number 2 -- Ootober 1968 70-volt neon-driver translstor, pages 138 to 140. The ten number and incandescent drl Vel'S can be ,e.erators produoe the necessary had tor about 10¢, surplus. horlzontal and vertioal vave Sylvan1a·. inoandesoent display anapes by a slmple shaping ot a lamps are much ea8ier to use, but 60-oyole input. c08t about 6S¢ per bit, with sockets. COMPUTER SOHEMATIOS ••••••••••• ** ••• Oontrol Data has, tor .34.50, a Intormat10n on how to age and se malnt enance and tra1nlng manual, lect neon lamps is oontained 1ft oontainlng some dlagrams, on the "Build This Eleotronio Computer,' LGP 21 and the RPC 4000, both In in the November, 1966, issue ot the eaae pUblloatlon, Pub. No. Electron10s Illustrated. The de IlSl) 10600. v1ce is actual11 an acoumulator rather than a co.,uter. !he ODC 150-A Oompater System Customer Eng1neering D1agr... Man Volce Output ual, Pub. No. 600 142 ls $2.70 ~ per oOP1. One member has a volce output tor his oomputer. Two stereo head8 All Inqulries and orders should are staggered to proVide four be sent to: tracks. Each track ls subdivided into three sub-bands to provlde LIterature Dlstrlbutlon Oenter ten ohannels and a control chan Control Data Corporation nel. 1015 South 6th Street Mlnneapolls, Kinn. 55440 CRT Dlsplal The LGP and RPO were prev10usly For those amateurs lnterested ln sold bT the Llbrasoope Dlvls10n cathode-ray-tube di8play, an in at General Preclaloni betore that, formative surv., artiole is oon the :apC was aold by the Royal tained in the January 1965 isaue McBee Oorp. ot Electro-Teehnolog1, "Digital to-Visible Character Generatora,' The LaP 21 haa 450 tranSistors, b1 Sherman H. B01d, pagea 77-'18, 375 diodes and no oores. Stll1 In 80, 84, 87-88. systems most produotion, Its main trame oost. ~e 11kely to appeal to amateurs are ·'16,000. Deek-slze, It welghs 90 dot generators and veotor genera pounds, has a magnet10-dlsk meDl tors. ory with 4,096 31-blt worde, 23 Inatruotions. Slngle-address, Pete Showman believea a crt SJstem serlal arithmet10. Paper tape and to be considerab11 oheaper than a typewrlter Input/output. Nixie-tube readout tor more than one reglater, and Infinlte11 mar. The BfO 4000 oontalns 500 tran versatile. He thinks an alpba slstora, 4500 d10dee, no ooree. numer12 display could be built for Origlnal prloe, $87,900; now, out under 1150, and a nnaeric-onlT ot produotlon, $28,000. The size system tor about halt a. auGh. ot two desks, it welghs 900 1bs has a drum meDlory with 8001 WOrtd S, An interestlng twlst la tound in 32 bits eaoh. Two-address, aerlal "For.log HandwrItten-Like Digit. arlthmet1c, 36 In.truotlons. Paper on CRT D1aplar," by R.L. White, tape and typewrlter Input/output. in Eleotron10., March 13, 1959, Number 2 -- Ootober 1966

Description:
The Amateur Computer Society was launched on the engineers; several work for com- puter manufacturers (IBM 3. Display. \'Jh.ich is cheapest-1 .. Although Teletype gear 1s slow and awJtwarc1 . Boston, Massachuaetts 02101 . (catalog). Cinoinnatl, Ohio 45217. Selectronios. 12 South N~a st.
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