Re: Recipes?

On Wed, 13 Jan 1999, Bruce Hayden <bhayden[_at_]ieee.org> wrote:
>
> Actually, things are/were a bit more varied. I am sure that I am
> going to leave some stuff out here, but here goes:
>
> word size char size chars/word architecture Company
> --------- --------- ---------- ---------- ------------------
> 16 bits 8 bits 2 Mini/Micro Intel,Moto,DEC,DG
> 24 bits 6 bits 8 PDP?? DEC
> 24 bits ?????? ? DSPs TI,Moto
> 36 bits 6 bits 6 1100 Univac/Sperry/Unisys
> 36 bits 6 bits 6 GCOS 8 GE/Honeywell/Bull
> 36 bits 9 bits 4 1100/2200 Sperry/Unisys
> 36 bits 9 bits 4 GCOS 8 Honeywell/Bull
> 48 bits 6 bits 8 A/B series Burroughs/Unisys
> 48 bits 8 bits 6 A/B series Burroughs/Unisys
> 60 bits 6 bits 10 6000 CDC
> 60 bits 7 bits 8 6000 CDC
>
> It should be noted that most of these architectures are still
> being manufactured (the exceptions I believe are CDC and the PDP).
> The companies separated by "/" indicate sucessive ownership of
> the architecture.

Actually, Bruce, I think it gets even weirder...

Some of the earliest operating systems for computers made by the companies you've named above allowed programmers (and/or systems operators, although there wasn't much difference back then) to set the word length themselves. For the same reason we have the Y2K bug (limited amounts of random access memory in early machines), "variable word length" was considered a "good thing." If a program could be written with a word length or 4, 5, or 6 bits, it might load into the limited memory on a computer of the time while the same program written to support 8 or longer bit words would be considered wasteful. Thus, more sophisticated (i.e. longer) programs could be written by using shorter words...

Everything I've ever read has credited IBM engineers with "standardizing" the industry on 8 bit bytes and word lengths in increments of 8.

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   Craig A. Summerhill, Systems Coordinator and Program Officer
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