To learn more about the system and what errors it will detect and report, I am looking at waveforms and playing with the system under various configurations.
Not completely unrelated, the simplified diagram for the Intel 7254 drive transistor bridges that run the X and Y coils in the 7110 bubble looks like this---
If you ever wondered to yourself "Does the 7254 have pull downs on the gates that keep the FETs from floating ON which would result in the chip shorting itself from +12V to ground and therefore burning itself up?" Well, the answer is no.
Note to self--- The 7254 has nothing to keep the gates from floating on. Never run the 7254 without the pre-coil drive 7250 in place. I don't know if this set still works, but I doubt they are still a matched pair as when new and now the tip of my finger smells like a combination of melting plastic and burnt flesh. I am glad they were a recovered set and not my good chips.