General Question about UNIBUS backplanes

william degnan billdegnan at
Sun May 22 12:23:22 CDT 2016

On Sun, May 22, 2016 at 1:10 PM, tony duell <ard at> wrote:

> > Are you saying remove all of the GC cards, just leave the slots blank?
> Yes, from the slots that are designed to take the core memory or its
> controllers (I assume, given you have special backplanes, there are
> boards with the core planes on, and more boards with the XY drivers
> or the sense/inhibit logic on).
> Do you have a diagram of where the core boards should go. If so, are
> there slots in the backplane left over. What are those 'extra'
> slots for?
> -tony

I have core memory cards that fill these backplanes from another system.  I
removed the cards, kept them sorted for re-insertion after I get the
backplanes communicating properly.  So, this is just a temporary set up.

I wanted to migrate the core to a different 11/40 because I have the CPU
and power supply tested and working.  By eliminating power and CPU
variables I can troubleshoot just the core cards one at a time.  I have a
few core cards that work so I will be able to work through the unknowns in
this system.    The system they came from needs power supply work, etc.
Too many things to try to fix all at once.

Thanks for the help.

@ BillDeg:
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