At one time I used a CDC 1604. It used an octal representation, 48 bit words, most instructions were half words (24 bits) except branches (jumps) that used full words (this is all by memory, so I could be wrong on some details). It used dumps in octal. Bytes on this machine were 6 bits, nibbles 3 bits. For the time it was a killer with virtual memory implemented on 7 track magnetic tapes (no disk, at first) and paged parts of the operating system in from this 7 track 256bpi mag tape. Yes, you could see the bits if you used 'mag tape developer' on it.
I forget who had 36 bit words, but I seem to remember some mainframe wanta-be did. It might have been Univac before they merged with Sperry. Again I am fuzzy there. 32bit was the mainstay of the larger machines for years, and eventually 64bit double word floating point. CDC kept going with 60bit words on the 6600 and larger series (with double word floating point being 120 bits). But for commercial work the IBM style 32 bit word won out for the most part. I don't remember 18 bit computers, but the PDP 8 was a 12 bit machine and most others went to 16 bit processors (like other DEC, DG, HP, etc). That is not saying there weren't any. Hey, even IBM did a decimal machine (1620 I think), again fun to play with when they were already old in the mid 1970's. ><> ... Jack Whatever you do, work at it with all your heart... Colossians 3:23 On Thu, Oct 28, 2010 at 11:04 PM, Dave Close <[email protected]> wrote: > Brandon S Allbery KF8NH wrote: > >>I'll add that "octet" is itself something of a leftover from when the 36-bit >>dinosaurs walked the earth. > > That doesn't seem right to me. Certainly 36-bit machines (and 12-bit and > 18-bit ones) frequently divided instruction words into 3-bit units and > used octal notation to represent them. But 36%8 != 0. > -- > Dave Close, Compata, Irvine CA +1 714 434 7359 > [email protected] [email protected] > "Paying attention to politicians can make you dumb." - Declan McCullagh > > _______________________________________________ > Tech mailing list > [email protected] > http://lists.lopsa.org/cgi-bin/mailman/listinfo/tech > This list provided by the League of Professional System Administrators > http://lopsa.org/ > _______________________________________________ Tech mailing list [email protected] http://lists.lopsa.org/cgi-bin/mailman/listinfo/tech This list provided by the League of Professional System Administrators http://lopsa.org/
