11/34 sanity check

Josh Dersch derschjo at gmail.com
Sat Apr 25 21:34:50 CDT 2015

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.
> - J.

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