John W. Colby
jwcolby at colbyconsulting.com
Thu May 19 08:40:02 CDT 2005
Look up octal. The registers on all the Sperry Univac machines that I learned in the Navy had little neon lights behind plastic buttons with springs in them with switches in them. Thus each button displayed the value of a bit and the button could be pressed to set the bit when hand programming them. The registers were "grouped" into 3 bits, each group represented an octal "digit" (which I quote since digit is specifically decimal). The entire machine, and all of its instructions were documented in octal. You could build word lengths of any multiple of octal "digits". The digital trainers in the 'C' school that I attended used a 15 bit machine. The first mini I worked on (Univac 1218 I believe was 18 bits, 6 octal "digits", and the Univac 642 a/b were 36 bits. All of them however were just multiples of octal "digits". That in no way means that something based around 9 bits didn't exist, but I would guess if you looked behind the curtains, they were all based on Octal, which comes out of the 40s and 50s. It wasn't until I got out of the Navy that I discovered Hex, based on groups of 4 digits. I suppose that machines might have been built based on 9 bits (having nothing to do with octal) for some specialty purpose. There's a LOT of strange stuff out there. John W. Colby www.ColbyConsulting.com Contribute your unused CPU cycles to a good cause: http://folding.stanford.edu/ -----Original Message----- From: accessd-bounces at databaseadvisors.com [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Stuart McLachlan Sent: Thursday, May 19, 2005 9:19 AM To: Access Developers discussion and problem solving Subject: RE: Integers vs. Long Integers Was: RE: [AccessD] Global Variable On 19 May 2005 at 7:23, John W. Colby wrote: > No, it was groups of 3 bit octal numbers. > > ??? http://www.perl6.org/perl6-language/2004-09/msg00108.html "The Honeywell 6000 (which is still around as a machine from Bull with a 6 in its name, I believe) was a word addressed machine. (Words were 36 bits long and could hold 4 9-bit characters packed into each one.)" http://www.freepatentsonline.com/4240144.html "Prior art systems, for example, the Honeywell 6000 family of computers stored operand 3 in the bank of registers with combination logic setting up the pointers to identify the number and positions of leading and trailing zones as well as the character size, 4 bits or 9 bits, within each word and the position of the sign, trailing or leading." http://minnie.tuhs.org/pipermail/tuhs/2004-October/001066.html "On page 182 of K&R 1st edition there's a reference to an implementation of C on the Honeywell 6000, with 9 bit bytes." -- Stuart -- AccessD mailing list AccessD at databaseadvisors.com http://databaseadvisors.com/mailman/listinfo/accessd Website: http://www.databaseadvisors.com