FW: [LINK] Is it Gb or GB?

[Chris Maltby]

> On Tue, Nov 07, 2006 at 04:03:54 +1100, Roger Clarke wrote:
> > At 15:21 +1100 7/11/06, Daniel Rose wrote:
> > >IIRC, bytes are only relevant inside a computer's circuit board.
> > >Architectures can use any number of bits for a byte, (or is that a
> > >word), seven was/is popular with some architectures.
> > 
> > My memory is that the word 'byte' arose with the IBM 360 c. 1964, and 
> > referred and always has referred specifically to an 8-bit block.  But 
 
On Tue, Nov 07, 2006 at 05:21:11PM +1100, John Clarke wrote:
> No it hasn't.  I've heard of 6, 7, 8, 9 and 10 bit bytes.  IIRC, the
> PDP-10 had a 36-bit word divided into 4 9-bit bytes, and some CDC
> mainframes had 60-bit words divided into 6 10-bit bytes.  I think 6-bit
> bytes were used by some IBM machines.

Oh, the horror, the horror!

The more usual division of 36 bit PDP-10 and PDP-20 words was as 6
6-bit characters. Those CDC 60-bit machines also used 6-bit bytes,
10 of them for every word - that's also because the "peripheral"
I/O processors had 12 bit data wordlength. Address registers for
both were 18-bits.

I never used any IBM machines with less than 8-bit units, but I'm
sure they must have existed prior to the 360 series. The existence
of EBCDIC is the proof of that...

And I also recall having to use a base64 method to squeeze 8-bit
binary ACSNet data across some horrible early international data
network which used 6-bit bytes as the transmission unit.

> 8-bit bytes have become the norm, but "octet" is still used in some
> standards to refer to 8-bits.  I don't know whether they still do, but
> back when I last had to use them, CCITT standards used "octet".

Correct. Octet is unambiguous.

Chris