KDJ11-B PDP 11/73 getting stuck in Exit standalone mode diag #56

[Noel Chiappa]

    > 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