A. Padgett Peterson P.E. Information Security
(PADGETT(_at_)hobbes(_dot_)orl(_dot_)lmco(_dot_)com) wrote this on 8/6/97 11:25
AM:
Just a loint of paw but a byte is not always 8 bits though this is
the common assumption today. If you asked an IBMer in 1981, the answer
was 9 bits. To a Baudot type it would be five bits.
The original definition was "that number of bits required to define
an alphanumeric character" (including some punctuation) so varied by
platform.
Now if you wish to define it as such, that is fine however "octet" is the
correct and specific term for eight bits.
Since you brought it up, here is a little more info on byte length from:
http://nightflight.com/foldoc/
(The Free Online Dictionairy of Computing)
-------------------
byte
<unit> A component in the machine data hierarchy usually larger than a
bit and smaller than a word; now most often eight bits and the smallest
addressable unit of storage. A byte typically holds one character.
A byte may be 9 bits on 36-bit computers. Some older architectures used
"byte" for quantities of 6 or 7 bits, and the PDP-10 and IBM 7030
supported "bytes" that were actually bitfields of 1 to 36 (or 64) bits!
These usages are now obsolete, and even 9-bit bytes have become rare in
the general trend toward power-of-2 word sizes.
The term was coined by Werner Buchholz in 1956 during the early design
phase for the IBM Stretch computer. It was a mutation of the word "bite"
intended to avoid confusion with "bit". In 1962 he described it as "a
group of bits used to encode a character, or the number of bits
transmitted in parallel to and from input-output units". The move to an
8-bit byte happened in late 1956, and this size was later adopted and
promulgated as a standard by the System/360 operating system (announced
April 1964).
James S. Jones <jsjones(_at_)jsjones(_dot_)graceland(_dot_)edu> adds:
I am sure I read in some historical brochure by IBM some 15-20 years ago
that BYTE was an acronym that stood for "Bit asYnchronous Transmission
E__?__" which related to width of the bus between the Stretch CPU and its
CRT-memory (prior to Core).
See also nybble, octet.