5 Feb
2015
5 Feb
'15
6 a.m.
On 05/02/2015 13:10, Noel Chiappa wrote:
I don't believe that's true. It's certainly not true in an 11/73 or
11/83, and I suspect the idea comes from one of the 11/84 manuals, which
only mentions one type of card (half- or fully-populated).
--
Pete Peter Turnbull
Network Manager
University of York
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.
I have this sneaking suspicion that the Q22 portions of those two slots aren't
_real_ QBUS slots (so you can't plug a QBUS device into them if you aren't
using them for memory :-), because I suspect they didn't run BIAK and BDMG to
those slots, but rather piped them directly to the UNIBUS adapter slot. My
reasoning for that is that if you don't plug in a memory card in one of those
slots, you don't have to plug in a grant continuity card, so....
But you're supposed to plug in a Minimum Load card, aren't you? I
wonder if those slots would work for a non-DMA device.
I seem to
remember that when two memory boards are used, they should be
the same.
Really? That would surprise me.