18 Aug
2019
18 Aug
'19
4:38 p.m.
Folks,
I've determined that the piece of my S/23 that's causing the power
supply to blow its 12V fuse is the machine update card. The manual says
this provides additional R/W storage for microprogram updates. That
sounds like something that wouldn't be necessary for normal operation.
Questions:
1. Can anyone confirm that I'm not losing anything by just pulling this?
2. Anyone have a cross ref for the IBM house numbers on these chips?
3. Anyone have a spare card they'd part with?
4. As long as I'm dreaming, anyone have a set of BRADS floppies or images?
Machine update card photo:
https://sysovl.info/pages/galleries/ibm/s23guts/s23guts13.jpg
Interestingly, the underlying PCB for this seems exactly the same as the
one for the word processing feature card.
Many thanks,
De
