On 2015-10-05 17:56, Henk Gooijen wrote:
-----Oorspronkelijk bericht----- From: Johnny Billquist Sent: Monday,
October 05, 2015 5:44 PM To: [email protected] Subject: Re:
PDP-11/10 repair started
Ok. I got the initial impression that you only had the CPU in. Thanks
for the expanded info.
When you don't have any core memory, I wonder if you might need bus
grants in those slots as well...? It's not as if they aren't a part of
the Unibus... Memory sits on the Unibus, just like everything else,
remember? Needs to check further if any special wiring are in place for
those slots, though.
Johnny
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I am not sure the "core slots" would need grant cards. The documentation
is clear about slot 3-4-5 as SPC, needing grant cards. I never saw any
doc where the core memory slots, when optional, but not installed, could
be used as an SPC slot. I certainly am Not "trying" that ...
I did try the system *with* the core slots filled with the correct boards
but the behavior remained the same.
To make fault finding not more complex, I removed the core board set.
Ok. Not sure if it makes it more complex or not, but I guess it's not
the issue right now anyway.
But my original comment about the behavior you described being very much
like what I've seen on other machines with bad/no termination still
applies. CPU seemingly stuck, but doing a master reset sortof gets it
out. But not functioning as it should.
Well, no more ideas here at the moment.
Johnny
