4 Apr
2017
4 Apr
'17
3:35 p.m.
From: Glen Slick
the Q22/Q22 backplane is not good for an 11/83 CPU ...
M8190 boards and
both have PMI signals on the CD half of the CPU board.
So I seem to recall hearing tales of PMI cards emitting smoke when plugged
into a Q/Q/ backplane. That doesn't seem to have happened here:
> I confirmed the KDJ11-B works fine in a BA23,
getting past test 56.
So I wondered if his off-brand backplane didn't have +12V or -12V wired up -
whatever it is that causes the damage. So I compared a list of PMI pins with
a QBUS pinout, trying to see if it was the +12V or 12V that would be the
problem.
However, I don't see any PMI pins that conflict? (Well, some of them are
ground, or +5V, but will that harm bus driver TTL?) Here's my list of PMI
pins:
CB1 PSSEL
CD1 PUBMEM
CE1 PBCYC
CF1 PUBSYS
CH1 PHBPAR
CJ1 PSBFUL
CK1 PLBPAR
CM1 PRDSTB
CP1 PBLKM
CR1 PBSY
CV1 PUBTMO
DB1 PWTSTB
DC1 PBYT
DD1 PMAPE
Anyone have any idea which pin(s) is the issue, when plugging a PMI card into
a Q/Q slot?
Noel