I just wanted to double check that I did this before replying, but I pulled
the M9302 again and this seemed to have no effect on anything - RUN and DC
ON lights and 000000 display still the same.
Looks like any further progress requires a scope, which I'll hopefully find
on Sunday. (hence my other thread, though I use it for other things)
-----Original Message-----
From: cctalk-bounces at
classiccmp.org [mailto:cctalk-bounces at
classiccmp.org]
On Behalf Of Tony Duell
Sent: Thursday, June 08, 2006 2:37 PM
To: cctalk at
classiccmp.org
Subject: Re: My continuing 11/34 confusion
Thanks to everyone who helped me figure this out. It can be confusing
sometimes when you think you've looked everywhere and it's still just in
the
wrong place.
Unfortunately, after properly checking the NPG and BG lines for
continuity,
I found that they are wired properly - I was hoping
for something simple
like that :(
So now that I know those lines are solid, and I know the Power supply is
outputting what it's supposed to, where do I go from here?
Next thing I would do is to pull the M9302 terminator. A single-backplane
machine like you currently have will run without it (at least for
testing) if everything else is OK. And the M9302 will lock the Unibus (it
asserts SACK and won't release it) if a grant gets all the way to the
terminator (the normal reason for this is that the chain is open at some
point, but you've checked this).
After that, I'd better get out the 11/34 printset and suggest good places
to stick the 'scope probe...
-tony