PDP-11/10 repair started

tony duell ard at p850ug1.demon.co.uk
Mon Oct 5 10:48:55 CDT 2015

> 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.

The core memory slots are specially wired (that's why the 8K and 16K
backplanes are different, one is wired for one set of core, the other
for 2 sets, with SPCs in the remaining slots). You do NOT put grant
cards in there.

In any case, an open grant chain will not cause problems at this stage of the
11/10. If you left out all the grant continuity cards the machine would still respond
to the console switches, let you load addresses, etc. So let's get that working


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