10 Oct
2004
10 Oct
'04
11:01 a.m.
On Sat, 2004-10-09 at 22:47 +0200, Gooijen H wrote:
I checked the wiring in my 11/70.
On this M9312, TP1 and TP2 are connected to a small push button which is
mounted on the bottom end of the front panel. Certainly not original,
but that is how I got this 11/70.
Thanks - just what I needed! :-)
From the MK11 MOS memory box above the 11/70 is
indeed a small cable
that connects to the M9312. This cable enters the 11/70 at the
rear side
and runs, over all the boards in the space where all the flat cables are,
to the M9312. The white/black goes on TP3, and the blank one goes on TP4. For its function, check the 11/70 manual :-)
Heh - I was staring at DEC engineering drawings for hours and it was
giving me a headache! I need to look at all the info for the memory
crate though as the CPU still isn't happy (the run lamp's permanently on
and we can't halt the CPU or toggle any data in from the front panel).
All cards look to be OK in the CPU though, but I suspect there may be a
problem with the memory...
I do not use the battery for MOS memory backup in case
of a power failure
so I can not be of much help here.
No problem - we're not intending on using it either; I just wanted to
check that it should be OK without it. Time to do some reading this
week!
We did discover the limit of the power cabling in the museum room though
- with the 11/34, 11/44, HP T500 and a few assorted terminals running we
hit the 30A limit on the breaker and blew the power out to the room :-)
Luckily we've found a few power outlets that are on a different breaker,
so we can move some big stuff over onto that and spread the load. Still,
adding the Marconi machine, Elliott 803 and the Decsystem 570 with the
three massbus drives into the mix is going to make things interesting.
The startup sequence for everything is going to be pretty critical...
cheers
Jules
16 Oct
16 Oct
4:22 a.m.
Heh - I was staring at DEC engineering drawings for
hours and it was
giving me a headache! I need to look at all the info for the memory
crate though as the CPU still isn't happy (the run lamp's permanently on
and we can't halt the CPU or toggle any data in from the front panel).
All cards look to be OK in the CPU though, but I suspect there may be a
problem with the memory...
I have seen the same problem with 11/34 systems when the bus grant and
interrupt daisy-chain was broken in the backplane. Are there any empty
Unibus slots? Did you check that the wire-wrap jumper is in place in the
non-DMA device slots?
Michael Thompson
E-Mail: M_Thompson(a)IDS.net
8:29 a.m.
On Sat, 2004-10-16 at 09:22 -0400, M Thompson wrote:
Thanks - we gave the bus a quick once-over and it looks OK, but I'll
have another look and really sit and stare at it. The cards *should* be
back in the places they were at when the system was last run, but I'll
triple-check it :) Interesting point about the jumpers; that's
something I haven't looked at at all - again it *should* be OK, but
maybe something's worked loose in getting the machine into storage ten
years or so ago and more recently when it was all pulled back out
again...
cheers,
Jules
Heh - I was
staring at DEC engineering drawings for hours and it was
giving me a headache! I need to look at all the info for the memory
crate though as the CPU still isn't happy (the run lamp's permanently on
and we can't halt the CPU or toggle any data in from the front panel).
All cards look to be OK in the CPU though, but I suspect there may be a
problem with the memory...
I have seen the same problem with 11/34 systems when the bus grant and
interrupt daisy-chain was broken in the backplane. Are there any empty
Unibus slots? Did you check that the wire-wrap jumper is in place in the
non-DMA device slots? 
8:48 a.m.
On Oct 10, 2004, at 2:01 PM, Jules Richardson wrote:
Heh - I was staring at DEC engineering drawings for hours and it was
giving me a headache! I need to look at all the info for the memory
crate though as the CPU still isn't happy (the run lamp's permanently
on
and we can't halt the CPU or toggle any data in from the front panel).
All cards look to be OK in the CPU though, but I suspect there may be a
problem with the memory...
Jules,
The run lamp on can also indicate a power problem of one kind or
another.
Check AC and DC LOW (the purple and yellow wires). If either is low,
there
is an issue. I bet the CPU microcode address is 0200, too.
If you already haven't, terminate the unibus at the end of the backplane
in the CPU cabinet.
Mike
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