12 Jun
2009
12 Jun
'09
7:42 a.m.
1) Is the NPG
grant on the unibus slot on the processor backplane (slot 9)
supposed to be connected to the NPG grants on the Unibus expansion? ?That is
-- right now if I set my DMM to continuity mode and put one probe on CA1 on
the first slot of the unibus expansion, and the other on CB1 on the last
slot of the unibus expansion, since all NPG grant jumpers are in place, the
DMM shows the circuit as closed. ?This is as I'd expect. ?However, if I move
the probe from CA1 on the first slot of the expansion to CA1 on slot 9 of
the processor backplane, the circuit is then open. ?I'm guessing this is not
correct. ?(There is currently an NPG jumper installed on slot 9.)
Are you *sure* slot 9 in the processor backplane really is a Unibus slot???
More correctly stated: the unibus out in the backplane A and B don't
neccesarily imply that C-F is a Unibus SPC slot.
I haven't checked the 11/40 drawings or manuals, and I assume you have been
reading them some. Please check this.
It's a big mistake to just assume that one slot is like another...