10 Apr
2015
10 Apr
'15
7:54 a.m.
-----Original Message-----
From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Paul
Koning
Sent: 10 April 2015 15:46
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Hand-wired core for ROM?
Rather than cores I believe that some machines had coils with drop in ferrite slugs. I
found this patent from 1972 which references IBM Patents..
http://www.google.co.uk/patents/US3691541
I also know the Elliot 803 used ferrite transformers in its logic sections...
On Apr 10, 2015, at 10:38 AM, geneb <geneb at
deltasoft.com> wrote:
Did the PDP14 (or any machine of that era) ever use hand-threaded (by the
end
user) core boards as ROM?
Do you mean DEC machine?
I don?t know any. Certainly not any PDP-11; those used solid state ROMs, or
in the early boot ROM cards, diode arrays.
I think some IBM 360 models used core ROM for microcode.
Another early machine ? the CDC 6000 series mainframes ? used a switch
matrix for the boot ROM (?deadstart panel?). And the character shape data
for the console display was originally implemented as a large pile of random
logic, though in the 170 series it turned into a conventional ROM.
paul