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

Glen Slick glen.slick at gmail.com
Sun Apr 2 20:58:00 CDT 2017

On Sun, Apr 2, 2017 at 11:49 AM, Mark G Thomas via cctalk
<cctalk at classiccmp.org> wrote:
> Unfortunately, I discovered slots are all wired Q22/Q22, no top ABCD
> (Q22/CD) PMI slots like a BA23. So, not good for an 11/83 CPU wired
> for PMI on slots C-D.
> So, I was hoping I could get my KDJ11-B (quad-wide 11/73) running in it.
> Upon power up or reset I get "Testing in progress. Please wait" on
> the serial console, and the LEDs get stuck on test 56. CTRL-C doesn't do
> anything yet, and my only options seem to be to hit reset, or if I hit the
> run/stop toggle, I can reset to the ODT prompt. This is with either just
> the KDJ11-B in the top slot, or with the addition of a suitably configured
> MSV11-QA in the next slot. If I turn off the LTC on the front panel,
> I get the expected Error 61 M8190 clock error, PC and register values,
> and options to re-run once or loop on test, so I know the LTC is working.
> I confirmed the KDJ11-B works fine in a BA23, getting past test 56. I also
> tried an 11/53 CPU here in the ABAB backplane and that gets past the self
> tests into dialog mode, but I really would like to get the KDJ11-B working
> in this chassis. I do see that a couple traces to the KDJ11-B C-D slots
> besides the Grant Continuity connections. I assume since the KDJ11-B
> has those Grant Continuity connections on slots C-D, it can run in a
> qbus/qbus Q22/Q22 quad Q-bus slot.

If you know the Q22/Q22 backplane is not good for an 11/83 CPU, why
would you think it would be any different for a KDJ11-B 11/73 CPU?
They are both M8190 boards and both have PMI signals on the CD half of
the CPU board.

Whether an M8190 KDJ11-B CPU board is called an 11/73, 11/83, or 11/84
is a boring discussion that has been rehashed here multiple times, the
important thing is don't put one in a Q22/Q22 backplane and expect it
to work correctly.


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