On 05/26/2019 10:44 AM, Jon Elson via cctalk wrote:
On 05/26/2019 12:13 AM, Mister PDP via cctalk wrote:
Ok, small update. My M8043 (DLV11-J) just arrived today.
It seemed in good
condition so I confirmed it was set up correctly (9.6k
baud and console on
J3), built a serial cable from the information provided
on gunkies, and put
it into my system. Sadly, it behaves exactly how it did
with the M8017. No
output, no activity on the BRPLY line. I have a hard time
imagining that
both my M8017 and my M8043 are bad, but it could still be
possible.
Well, if just ONE address line driver on the CPU has gone
bad (or a short in the backplane) it could prevent the DLV
from recognizing the address. If there are any other
boards in the system, take them out. Maybe even the
memory boards, and try to read/write the DLV addrsss from
the console. (Oh, maybe that's the problem, you don't
have the full programmer's console on this machine.)
Oh, DLV means Q-bus, so there isn't much choice EXCEPT
serial console, is there?
Yeah, when the serial console doesn't work, you've got a
problem. You could check each addr/data line to see that it
wiggles. If it doesn't wiggle, then you can see if the
state it is in makes sense. Obviously, somewhere in the
serial console routine, it should be addressing the serial
console, so every line should at some point be in the state
to select the console CSR.
A logic analyzer set up to read out the bus would be a good
tool at this point.
Jon
