They all have what I think are reasonable signals.
Couple of things:
1) I'm not always getting a reading from pin 20 (see attached file for an example)
2) UD7 signals are noticably stronger than 6, 8 or 9 (again, see attached comparison)
https://drive.google.com/file/d/1eGw...ew?usp=sharing
Colin.
Quote:
Originally Posted by SiriusHardware
That would have been too easy I suppose (you were looking for video and sync signals, but you don't appear to have them).
OK then:-
Reinstate the NOP rig so we can go back to those nice regular address and CS signals,
For each PROM in turn, with channel 1 of the scope on the PROM's CS1 pin (20), use channel 2 of the scope to look at the signals on DA0 to DA7, ideally at the 6502 socket pads, but if not, wherever you can get to them.
You need not post captures of all 28 instances, just make sure the data on those data lines is at reasonable logic '0' and logic '1' voltages in all cases. If you see anything which looks 'wrong' then by all means capture it and let us have a look.
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