10 Apr
2015
10 Apr
'15
8:43 a.m.
On 04/10/2015 07:54 AM, Dave G4UGM wrote:
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
Somewhere on the web, there's a good exposition S/360 microcode store.
Two systems (at least) used--one was capacitive (360/30 et al.) and the
other was what was called "transformer" memory. Very clever, both of them.
I believe that the CDC large machines used capacitor-type ROS.
--Chuck