[extropy-chat] Re: Poxy old computers

[David Lubkin]

My first programming was on a early PDP in 1973, in Israel, on 
optically-read Hollerith cards. We had to fill in the pattern for each 
letter with a pencil on the Hollerith card. Once a week, Ilan Cohen would 
take our card decks to run on the computer. If you made a mistake, you had 
to gamble as to whether you could erase your mistake well-enough that the 
reader wouldn't misread the card. If it did, you had to wait another week 
to try your program again.

It felt so cool the first time I got to use a keypunch machine and, a few 
years later, a terminal.

Going back twenty years earlier, my mother *was* a computer briefly (it 
used to be a profession), and my father ran the military computers at 
Letterkenny.

Before that, my grandfather began his computer career as the first 
production manager for the ENIAC, and then designed many of its successors 
(e.g., SEAC, EDVAC, REEVAC). I'm sorting through his invention disclosures 
and papers from the 1930's on and gradually pulling together a web site.

I did find a marketing brochure for the Elecom 100, though. He'd founded 
the Electronic Computer Corporation two years after ENIAC, and designed and 
sold the first mini-computer. The 100 represented a tremendous breakthrough 
in price/performance, selling for only $100,000 (worth about $750,000 in 
today's dollars). (He was undercapitalized, and eventually sold the company 
to Underwood.)

Bear in mind that we have gone from this to now within the span of one 
working career (roughly age 20 to 70). Here are the specifications:

MEMORY --  Magnetic drum, 512 word capacity.

WORD LENGTH -- 29 binary digits and sign.

ARITHMETIC OPERATIONS -- addition; subtraction; multiplication (with 
round-off); multiplication (unrounded; complete product available).

LOGICAL OPERATIONS -- logical multiplication; conditional transfer of 
control (branch); halt; input and output operations.

MAGNETIC TAPE UNIT -- single unit, using 1/2" tape on 1200 ft. reels. Data 
recorded in four channels including sprocket channel; 64 words per block, 
1600 blocks (102,400 words) per reel. Programmed operations: read one 
block; record one block; move tape backward one block without reading or 
recording.

TYPEWRITER -- standard electric model with actuators on numerical keys, 
negative sign, space, and carriage return. Programmed output operation 
calls for typing out one block of 64 words on eight lines with automatic 
carriage returns and spaces between words, using octal representation, or 
typing out one block using decimal representation which provides for 
programmed space, negative sign, and carriage return in addition to all 
digits from 0 to 9 inclusive. Manually initiated input of single word to 
any desired address, or sequences of words with any desired starting 
address. Input may be either octal or decimal.

SPEED OF OPERATION -- basic pulse 115 kcs., average time for internal 
operations 46 milliseconds, tape instructions approximately 1 1/4 seconds 
per block, typing out operation at rate of 7 1/2 characters per second.

EQUIPMENT SPECIFICATIONS -- approximately 180 tubes and 2000 crystal 
diodes; power consumption approximately 3 kva. Main computer 6 ft. high, 10 
ft. long, 2 ft. deep, arranged in a semi-circle; separate drum unit 2 ft. 
square. Control desk 34" x 60" holds typewriter, tape panel, and control panel.


-- David Lubkin.