pdbain@wateng.UUCP (Peter Bain) (04/30/84)
The IBM STRETCH (7030) ca 1957, was bit addressable. The instruction contained a word address (64 bit word) , bit offset, and a "byte length", or operand size. The machine was a masterpiece of baroque architecture: all sorts of nifty things that were practical to use only in assembler. The term "byte" was coined for the STRETCH, and originally ment a variable size operand. -peter
grt@hocda.UUCP (G.TOMASEVICH) (05/01/84)
The description of the IBM STRETCH reminds me of the IBM 1620. It represented data as BCD characters (8, 4, 2, 1, flag, check bits). Numbers had a flag bit at one end to mark the field. The arithmetic precision was continuously variable up to the capacity of the memory. I once set up memory to multiply two 10000-digit numbers; it took about a second. George Tomasevich, AT&T Bell Laboratories
nather@utastro.UUCP (Ed Nather) (05/01/84)
[]
From: grt@hocda.UUCP (G.TOMASEVICH)
_____________________________________________________________________________
The description of the IBM STRETCH reminds me of the IBM 1620. It represented
data as BCD characters (8, 4, 2, 1, flag, check bits). Numbers had a flag
bit at one end to mark the field. The arithmetic precision was continuously
variable up to the capacity of the memory. I once set up memory to multiply
two 10000-digit numbers; it took about a second.
George Tomasevich, AT&T Bell Laboratories
____________________________________________________________________________
Also of note: this machine did all its arithmetic functions by table
look-up, on character at a time. What is 3 X 3? Look in the table and
find "9" -- 7 + 4? 1 carry 1. It was *neat*.
It was also called the CADET -- (For Can't Add -- Doesn't Even Try.)
--
Ed Nather
ihnp4!{ut-sally,kpno}!utastro!nather
Astronomy Dept., U. of Texas, Austinrpw3@fortune.UUCP (05/02/84)
#R:hocda:-42000:fortune:11600091:000:472
fortune!rpw3 May 1 16:04:00 1984
But on an IBM 1620, the multiply (and I believe, even the add)
was done by table-lookup from a set of tables loaded into low-core
at boot time.
One of the favorite "jokes" (*not if you ask me*) was to "adjust"
the table and then walk away from the machine. The next guy in
line really had fun.
Rob Warnock
UUCP: {ihnp4,ucbvax!amd70,hpda,harpo,sri-unix,allegra}!fortune!rpw3
DDD: (415)595-8444
USPS: Fortune Systems Corp, 101 Twin Dolphin Drive, Redwood City, CA 94065gwyn@brl-vgr.ARPA (Doug Gwyn ) (05/03/84)
Actually the IBM 1620 had a later model that knew how to add single BCD digits, but it still looked up the multiplication table in core.
gwyn@brl-vgr.ARPA (Doug Gwyn ) (05/12/84)
Speaking of the etymology of the word "byte", this is a plea for the correct spelling of "nybble". thanks...
andrew@hwcs.UUCP (05/15/84)
>The IBM STRETCH (7030) ca 1957, was bit addressable. >The instruction contained a word address (64 bit word) , >bit offset, and a "byte length", or operand size. >The machine was a masterpiece of baroque architecture. Does my memory deceive me, or was this beastie so parallel and so unreliable as a result that it was renamed "TWANG"? - andrew stewart (...!ukc!edcaad!hwcs!andrew)