8 May
2015
8 May
'15
3:17 p.m.
From: tony duell
> I have a Plessey PM-D11/SPC-1 backplane here
How many slots? I assume it's hex height. What (if
anything) are the
power input connectors?
9; yes; it has the standard 9-pin connector as used on the 11/05-10, and the
early /40s and /45s. (FWLIW, the documentation for the PM-F11 says that _it_
comes with either the same 9-pin connector power harness, or the harness with
the newer 15-/6-pin connector pair, and gives part numbers for each.)
The harness of this one is subtly different, though - instead of all fast-on
tabs at the backplane end, there is a DuPont header on the backplane (looks
like 10 pin), and a bunch of the pins on the large 9-pin connector are
connected to that (not just ACLO and DCLO, but e.g. there are a pair which
are connected to +5V, and another pair to ground (the latter two also go to
fast-on tabs).
Is there any reason to assume it's not a clone of
a standard DEC
backplane ... the 'SPC' part of the name suggests a Unibus peripheral
backplane
Oh, I'm sure it's _some_ form of SPC backplane - it has the NPG jumpers from
CA1 to CB1 on all 9 slots, for instance. And it has a bunch of wires running
from 1A/B down to the CDEF part, and then back from
CDEF to 9A/B. And the NPG
is routed from 1A down to CA1/CA2, and then back up to
9A.
But I'm trying to figure out exactly what sort of SPC backplane it is. E.g.
it looks like slots 2-8 _might_ be MUD (the signals from 1A/B are bussed
across all those slots on A/B, over to 9A/B). But without documentation, or
a lot of ohm-meter work...
Noel