off topic - capatob - saratov2 computer Russsian pdp8

Dave Wade dave.g4ugm at gmail.com
Sun Jan 6 23:24:11 CST 2019



> -----Original Message-----
> From: cctalk <cctalk-bounces at classiccmp.org> On Behalf Of William Donzelli
> via cctalk
> Sent: 06 January 2019 23:21
> To: Bob Smith <bobsmithofd at gmail.com>; General Discussion: On-Topic and
> Off-Topic Posts <cctalk at classiccmp.org>
> Subject: Re: off topic - capatob - saratov2 computer Russsian pdp8
> 
> > With the advent of wide spread introduction of 16 bit machines the
> > definition of a byte as an 8 bit unit was accepted because ASCII
> > supported character sets for multiple languages, before the 8bit
> > standard there were 6 bit, 7 bit variations of he character sets.
> > Gee, what were teletypes, like the model 15, 19, 28, oh yeah 5 level
> > or 5 bit..with no parity.
> 
> Byte was more or less "set in stone" in the mid 1960s, with the success of the
> IBM System/360. During the internal war at IBM to determine whether the
> S/360 was going to be a 6 bit based machine or an 8 bit based machine, a
> study showed that a huge majority of the stored digital data in the world was
> better suited to 8 bits (mainly because of BCD in the financial industry). It had
> nothing to do with terminal communications, as there just was not much of
> that back then.
> When the S/360 turned into the success it was, maybe 1966 or so, it turned
> into an eight bit byte world.
> 
> People on this list keep forgetting just how gigantic IBM was back then, and
> how much influence it had, good or bad.
> 
> --
> Will

I am also pretty sure that prior to S/360 the term "character" was generally used for non 8-bit character machines. I am not familiar with the IBM 70xx series machines but certainly on the 1401 and 1620 the term byte was never used. Also the Honeywell H3200 which was an IBM1401 "clone" (sort of). The only machine I know where a "byte" is not eight bits is the Honeywell L6000 and its siblings These machines had 36 bit works which were originally divided into 6 six bit characters. When it became clear that the world was moving to 8-bit characters they added new instructions that allowed a word to be treated as 4 by 9-bit bytes.

I seem to recall that some IBM machines also had facilities to read all 9 bits from a 9-track tape as data so 9-bit bytes but I can't find references.

I also feel the use of the term Octet was more marketing to distance ones machines from IBM.....

Dave



More information about the cctalk mailing list