11/34 sanity check
j_hoppe at t-online.de
Sat Apr 25 15:32:03 CDT 2015
Am 25.04.2015 um 06:32 schrieb Josh Dersch:
> 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
> 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.
All LEDs "glowing dark"?
I've seen this too, when the 20 pin cable from M7859 to the console
panel is plugged in reversed.
Don't trust the marked Pin 1 wire: sometimes DEC manufacturing twisted
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