Re:ILLIAC I Programming Manual (1956) [pdf]
by cryptnotic on Monday May 12, 2014 @03:47AM
(#7731571)
I just had to search for it.
From: http://en.wikipedia.org/wiki/ORDVAC
"Unlike the other computers of its era, the ORDVAC and ILLIAC I were twins and could exchange programs with each other."
"Instead of the sequence A B C D E F universally used today, the digits ten to fifteen were represented by the letters K S N J F L (King Sized Numbers Just for Laughs), corresponding to the teleprinter characters on five-track paper tape."
The info you quote is a description and not the answer. The whole alphabet is on the page 9-5. I still don't know why there isn't some "order" in encoding (like it is now in ASCII, that would still result in the encoding for 10 to be A and not K. and it's not a USTTY http://en.wikipedia.org/wiki/Baudot_code there is K == 01111) but I'd expect they must have had some reason.
It looks like they took the ITA2 telegraphy code, which has the numbers in normal order but the letters in typewriter order, and re-sorted it so that the letters are alphabetical. That would explain the scrambled numbers, but not the punctuation or "K S N J F L".
http://en.wikipedia.org/wiki/ILLIAC
"ILLIAC I was built at the University of Illinois based on the same design as the ORDVAC. It was the first von Neumann architecture computer built and owned by an American university. It was put into service on September 22, 1952.
ILLIAC I was built with 2,800 vacuum tubes and weighed about 5 tons. By 1956 it had gained more computing power than all computers in Bell Labs combined. Data was represented in 40-bit words, of which 1024 could be stored in the main memory, and 12800 on drum memory."
The interesting information from the manual is that the computer had 40-bits fixied-point arithmetic, directly calculating only numbers between -1 and +1. If was certainly very demanding programming it.
Another interesting detail: the puritans still didn't influence the name of the number system, they write about "sexadecimal" coding, and interestingly use "0 1 2 3 4 5 6 7 8 9 K S N J F L." Why "K S N J F L"? I don't know.
And a really fascinating detail: it was not only punched tapes and stuff: it had a 256x256 pixels CRT as an output device too. Sample on pg. 12-9