11/34 sanity check
Josh Dersch
derschjo at gmail.com
Sun Apr 26 00:09:45 CDT 2015
On 4/25/15 7:34 PM, Josh Dersch wrote:
> On 4/25/15 9:34 AM, js at cimmeri.com wrote:
>>
>>
>> On 4/24/2015 11:32 PM, Josh Dersch wrote:
>>> While I was waiting for the Ridge's disk to dump over a 9600bps
>>> serial port, I finally got a chance to work on my 11/34. Picked it
>>> up last summer and it was in good shape but the power supply was
>>> completely dead. I've rebuilt the supply and last night I worked
>>> out the last few kinks.
>>>
>>> So at this point all voltages are spot-on, the AC LO and DC LO
>>> signals are high (these are active low, right?) but I can't get the
>>> machine to respond at all -- the "DC ON" and "RUN" lights are lit up
>>> brightly, and the "SR DISP," "BUS ERR," and "MAINT" lights are
>>> glowing dimly. The status register display is dark. The system does
>>> not respond to any keypresses on the panel.
>>>
>>> I'm getting better with UNIBUS stuff but I wanted to run this past
>>> you guys before I whip out the debugging tools and start tracing
>>> things. I've taken it down to a pretty minimal configuration, sans
>>> any memory or other stuff. Here's what I have in the main backplane
>>> (all others are disconnected for the time being) from right to left:
>>>
>>> Slot 1: M7266 (CPU)
>>> Slot 2: M7265 (CPU)
>>> Slot 3: (AB) M9301 (bootstrap terminator) / (CDEF) M7859 (front
>>> panel board)
>>> Slot 4: empty
>>> Slot 5: empty
>>> Slot 6: empty
>>> Slot 7: empty
>>> Slot 8: empty
>>> Slot 9: (AB) M9302 (terminator)
>>>
>>> The "empty" slots have Grant Continuity boards installed and the NPG
>>> jumpers on CB1-CB2 are all present on the backplane. I've confirmed
>>> that all the right voltages are making it to the backplane (and I've
>>> cleaned up those damned Molex connectors as well, just to be sure).
>>> Is there anything I'm missing? Anything I should try? Does this
>>> failure mode sound familiar at all?
>>>
>>> Thanks as always,
>>> Josh
>>
>> J, try this first:
>>
>> - test your M7859 KY11-LB console and a ram board in maint mode
>> direct access. See the manual for the KY11 for how to do this. Use
>> maint mode #5 to check your MS11 at select locations, per installed
>> boards eg. M7847 16K RAM, M9301+M9302, M7959 console. Keep the CPU
>> out of it for now.
>
> Thanks, I'll give that a shot later tonight.
Update: In addition to not responding to normal keypresses, the front
panel also doesn't respond to maintenance-mode keypresses (CTRL-1,
etc.). So the problem I'm currently seeing seems to be related to the
KY11 and thus commences my debugging session :). I think I may dump the
PROMs first to see if they still hold valid code...
- Josh
>>
>> - J.
>>
>>
>>
>>
>>
>>
>
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