behaviour of classic PDP-8 frontpanel

Bill Degnan billdegnan at gmail.com
Tue Oct 30 12:28:06 CDT 2018


On Tue, Oct 30, 2018 at 1:21 PM Paul Koning via cctalk <
cctalk at classiccmp.org> wrote:

>
>
> > On Oct 30, 2018, at 1:14 PM, dwight <dkelvey at hotmail.com> wrote:
> >
> > My  Nicolet did the same thing it would load 0 into the intended start
> location ( on my machine it was a jump to 0 ).
> > The front panel worked fine otherwise. It turned out to be some missing
> clocks because of a bad 7474. Strange that a common problem on different
> machine created by completely different issue but all writing 0 back to
> core.
>
> Not all that strange.  Reading core clears it.  So if the restore cycle is
> either suppressed or diverted to the wrong address, you keep that zero at
> the location just read.
>
>         paul
>
>
>
I believe the straight 8 is set up and ready for testing at the vcfed.org
museum, call someone there to mimic your tests.


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