Fabritek MP-12 Loader

William Donzelli wdonzelli at gmail.com
Thu Dec 3 10:41:08 CST 2015

> So far, we've been able to find the device codes for
> updating the 7-segment LED displays on the front, turning on and off
> relays, and setting some arbitrary open-collector outputs.

Do you mean the seven segment displays on the paper tape reader?

> There are three 512-by-4 bipolar (configured as 512-by-12) PROMs that seem
> to override the core memory at the top of the 4k field. If the PROM's value
> is 7777 octal, the core memory is accessible. Otherwise, you're stuck with
> ROM, best I can tell.

So if you jam the PROMs output to 7777 for any address, you can get to
all the core (and make the machine useful)?

The source for the PROM may be with that CD I gave to Al.


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