12 May
2019
12 May
'19
12:16 a.m.
-----Original Message-----
From: cctalk <cctalk-bounces at classiccmp.org> On Behalf Of Steve Malikoff
via cctalk
Sent: 12 May 2019 01:50
To: General Discussion: On-Topic and Off-Topic Posts
<cctalk at classiccmp.org>
Subject: Re: How were 32-bit minis built in the 70s/80?
Warren said
Also in the UK GEC used AMD2900 IC's for some of the GEC4000 series. Some details
here:-
https://en.wikipedia.org/wiki/GEC_4000_series
we used them in NERC (Natural Environment Research Council, www.nerc.ac.uk) as both X.25
packet switches and as general purpose computers in which role they were universally hated
as the Fortran compiler was ANSI compliant in the draconian sense of the word and the
scientists were used to DIGITAL Fortran which had many extensions.
Some history of the JANET network here:-
https://www.jisc.ac.uk/sites/default/files/janet-news-24-pull-out-april-201…
Dave
I'm building my own 8-bit CPU from TTL chips,
and this caused me to think:
how were 32-bit minis built in the late 70s and early 80s? In
particular, how was the ALU built? I know about the 74181 4-bit ALU,
and I know (from reading A Soul of a New Machine) that PALs were also
used.
Did companies get custom chips fabricated, or was it all off-the-shelf
chips with a few PALs sprinkled in?
Thanks, Warren