Looking for info on memory

Nigel Johnson Ham g4ajq1 at gmail.com
Thu Oct 21 08:10:46 CDT 2021


Thanks, but like bitsavers they are all older that the one I have.

To be honest, I never saw anything Plessey bigger than 128kB in the
wild, so I have to wonder what kind of machine this board came from,
although it was in a pile of Qbus things that I got the J boards from.

I'm thinking that maybe it was not sold separately, but an OEM build for
military etc, and perhaps it is jumpered to get power from memory - but
without the manual or tracing the lands I can't really tell.

cheers,

Nigel



On 2021-10-21 7:25 a.m., Steve Malikoff via cctalk wrote:
>> 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?
> FoothillsGeek on VCFed had a number of Plessey memory manuals and had scanned
> some, as mentioned here
> https://www.vcfed.org/forum/forum/genres/dec/73251-dec-documents-on-manx
>


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