On 10/19/2021 12:57 PM, Nigel Johnson Ham via cctech wrote:
I am trying to bring up an 11/23 system in a BA23 box, and the only
memory i have is an obscure Plessey one. The only identification is the
p/n 705920 with dash-100 in white ink. By counting the chips I make it
4MB, but it does not respond. Since it takes the full 22-bit memory
space I can't see how any jumpers would change its accessibility. Does
anybody have a manual?
any help appreciated,
Nigel Johnson
Looking at the photo I began to wonder if Plessey made their own boards
or are they re-badged from some other manufacturer. I don't know. If
they are made by someone else, you might be able to dig up a manual.
Also, if you look at the documentation for other 4MB qbus memories how
many jumpers do they have? And what do they do? It may help you
understand your board.
Doug (of course I don't have a 4MB qbus memory, but that apparently
didn't stop me from posting.)
