7 Feb
2015
7 Feb
'15
6:03 p.m.
Noel Chiappa wrote:
From: Jerome
H. Fine
The MSV11-JB (1 MB) and MSV11-JC (2 MB) are used
in the PDP-11/84. The
MSV11-JD (1 MB) and the MSV11-JE (2 MB) are used in the PDP-11/83.
Err, not sure this is correct: I got an 11/84 with an MSV11-JD in it. As
someone pointed out in a later message, the difference between the B/C and
D/E is that the B/C only work as PMI memories, their QBUS functionality has
some issues (IIRC, something to do with QBUS block transfers not working
correctly).
In addition, for at least the PDP-11/83, the PMI
memory must be placed
into the backplane ahead of the CPU for the memory to function as PMI
memory. That may be the only position allowed for the memory for the
PDP-11/84.
The 11/84 backplane has two special Q22/CD slots after the processor slot
which the memory goes in, with the CD sections wired to through-connect the
PMI pins.