PDP-11/10 repair started

Henk Gooijen henk.gooijen at hotmail.com
Mon Oct 5 10:56:59 CDT 2015

-----Oorspronkelijk bericht----- 
From: Johnny Billquist 
Sent: Monday, October 05, 2015 5:44 PM 
To: cctalk at classiccmp.org 
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.



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.

- Henk

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