PDP-11/10 repair started
Jon Elson
elson at pico-systems.com
Sun Oct 4 22:58:04 CDT 2015
On 10/04/2015 01:09 PM, Henk Gooijen wrote:
> Some corrections to my post regarding the console LED
> behavior.
>
> Voltage levels on the CPU backplane are still good whne
> the 2 CPU boards
> are installed in the backplane, but the processor is not
> responsive to
> the switches on the console panel.
>
> The RUN LED is on, ADDRESS/DATA are all off.
You have no memory, and probably no devices to complete the
Unibus. So, it is quite likely showing the Unibus is in a
jammed state. At the least, you need a Unibus terminator,
and any bus grant cards between the CPU and the terminator
(you'd have to check the manual to see how the Unibus is wired.)
Jon
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