Jeff,
A byte is the least addressable portion of memory. The IBM 1401 for example
has 6 bit bytes + a word mark. Parity bits don't count. A lot of systems
in the 50's and early 60's had 6 bit bytes. That is why octal became so
popular.
Bytes were not used for systems like the IBM 1620 which was a scientific
system. Memory was an array of number registers and was not character
based. Instead the least addressable memory unit was a word.
A byte may be 8 bits now but it was not always 8 bits.
Carl
-----Original Message-----
From: unicode-bounce@unicode.org [mailto:unicode-bounce@unicode.org]On
Behalf Of Jeff Guevin
Sent: Thursday, March 22, 2001 12:01 PM
To: unicode@unicode.org
Subject: [unicode] Re: UCS-2 Files
>
> On Thu, 22 Mar 2001, marco.cimarosti@essetre.it wrote:
>
>> Better if you also keep the distinction between "octet" (a series of
>> 8 bits) and "byte" (a series of n bits, where n is often but NOT
>> always 8).
>
> When is a byte not eight bits?
>
The Web version of the Oxford English Dictionary (http://dictionary.oed.com)
says a byte is always eight bits:
"A group of eight consecutive bits operated on as a unit in a computer."
1964 BLAAUW & BROOKS in IBM Systems Jrnl. III. 122 An 8-bit unit of
information is fundamental to most of the formats [of the System/360]. A
consecutive group of n such units constitutes a field of length n.
Fixed-length fields of length one, two, four, and eight are termed bytes,
halfwords, words, and double words respectively. 1964 IBM Jrnl. Res. &
Developm. VIII. 97/1 When a byte of data appears from an I/O device, the CPU
is seized, dumped, used and restored. 1967 P. A. STARK Digital Computer
Programming xix. 351 The normal operations in fixed point are done on four
bytes at a time. 1968 Dataweek 24 Jan. 1/1 Tape reading and writing is at
from 34,160 to 192,000 bytes per second.
> --
> Gaute Strokkenes http://www.srcf.ucam.org/~gs234/
> PEGGY FLEMING is stealing BASKET BALLS to feed the babies in VERMONT.
>
>
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