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From: "Brian R. Hanson" <brh@cray.com>
Subject: Re: Rules for Representation of Subtypes
Date: 1996/10/01
Message-ID: <325179AD.41C6@cray.com>#1/1
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references: <dewar.844014110@schonberg> <52oi3v$din@mill.gdls.com>
 <1996Oct1.125614.1@eisner>
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Date: 1996-10-01T00:00:00+00:00
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In article <52oi3v$din@mill.gdls.com>, schwarza@gdls.com (Art Schwarz)
writes:
> Nearest that I can remember, byte size varies by machine. It is NOT an
> eight byte quantity. This is probably the motivation to use _octet_
> instead of bytes in formal descriptions.
>
>   An example of byte sizes:  CDC 1604    6 bits
>                              CDC 6000   12 bits
>                              PC          8 bits
>                              UNIVAC 1100 7, 8, 9, 12 bits
>                              PDP-10      7 bits (and others?)

On the CDC 6xxx line a "byte" was probably 6 bits - the size needed
to typically represent a character.  12 bits was the size of a parcel
which was the minimum size for an instruction.  12 bits was also the 
size of a word of memory in the associated peripheral units used to 
do io to and from memory. The smallest addressable unit of storage 
for the main processor was 60 bits - the size of a word.  

-- Brian Hanson
-- brh@cray.com