-----Oorspronkelijk bericht-----
From: jwsmobile
Sent: Friday, June 03, 2016 7:51 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: PDP-11/94-E
On 6/3/2016 9:11 AM, Jerome H. Fine wrote:
>Rod Smallwood wrote:
>On 03/06/2016 16:43, Jerome H. Fine wrote:
<snip>
Hi its a KDJ11-B all memory on CPU board
Rod
I am very confused. Is your mention of memory on the CPU board
for the PDP-11/83 or the PDP-11/93? I thought that the PDP-11/83
never had memory on the CPU board (assuming that the cache is not
regarded as memory).
This aspect of the thread is probably no longer relevant, I just wanted
to note that PMI memory can be used with what most individuals would
consider to be a PDP-11/73 (naturally a quad) board and the PMI
aspect of the memory will be activated when the PMI memory is
installed ABOVE the CPU board.
Also when PMI memory is installed BELOW the backplane, it is then
used as normal Qbus memory in a Qbus system. I can't see anyone
doing that, but it is allowed.
Jerome Fine
I suspect it is using this board.
M7554-02-KDJ11-DB-WITH-1-5MB-MEMORY-ON-BOARD-USED
http://www.ebay.com/itm/161791207076
I am guessing the 1.5mb isn't cache, but is system memory on this board.
There is also the KDJ11-BF which has no memory on board. M8190-AE.
thanks
Jim
----
Nope, the M7554 is the PDP-11/53 CPU.
The 11/83 had its memory on the bus (either left or right of the module).
The 11/94 did NOT have memory on the bus, because *all* memory is
on the CPU module itself. Note that there are two versions of the 11/94.
One with 2 MB RAM and one with 4 MB RAM (all that can be addressed!).
The 2 MB version and the 4 MB version are identical, just half the RAM chip
population is not placed. However, all through-hole pins are soldered so
the upgrade from 2 MB to 4 MB would be a real PITA, *if* you'd try it at all!
- Henk
