Amateur Computer Society newsletter, 1966-1976

245 Pages·2012·9.66 MB·English

~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