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From: martin@felix.UUCP (Martin McKendry)
Newsgroups: comp.unix.wizards,comp.arch
Subject: Re: *Why* do modern machines mostly have 8-bit bytes?
Message-ID: <3766@felix.UUCP>
Date: Thu, 23-Jul-87 17:00:15 EDT
Article-I.D.: felix.3766
Posted: Thu Jul 23 17:00:15 1987
Date-Received: Sat, 25-Jul-87 15:27:41 EDT
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Reply-To: martin@felix.UUCP (Martin McKendry)
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In article <2807@phri.UUCP> roy@phri.UUCP (Roy Smith) writes:
>
>	First, why did older machines have all sorts of strange word
>lengths -- 12, 36, and 60 being sizes that I know of, but I'm sure there
>were others.
>-- 
>Roy Smith, {allegra,cmcl2,philabs}!phri!roy
>System Administrator, Public Health Research Institute
>455 First Avenue, New York, NY 10016

Last year I was with Burroughs, doing a little work on the history
of the A-series (B5500, etc).  This machine has a 48-bit word.  Turns
out that it was set to 48 because at that time they thought characters
were going to be 6 bits (we're talking 1957 here, folks), and they
wanted a power-of-2 wordsize.  Of course now they do these wonderful
divide-by-3's to do character addressing (its word addressed).  And,
naturally, no true Burroughs hackers believe that there is any advantage
to having a power-of-2 number of characters in a word.  You ought to
see the code and microcode executed to do Cobol!

--
	Martin S. McKendry
	FileNet Corp
	{hplabs,trwrb}!felix!martin