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Old 31st Jan 2021, 7:37 pm   #412
SiriusHardware
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Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
Posts: 11,485
Default Re: Non-working Commodore PET 3016

Are you referring to the last capture in Colin's link, which appears to show 6502 A10 looking normal but BA10 (after being cut away from UB3 pin 16) riding high? Not sure, but don't TTL inputs traditionally float high if not specifically driven?

As we don't appear to have a similar machine among us to make comparisons with I think that avenue is closed, unless you can draw on your extraordinary information mining skills to find us a full set of system waveforms somewhere.

Which brings us back to the question, replace the buffers, or try some other thing?

Although most of the devices which are driven by BA10 are in sockets, you may be right, if the drive out from UB3 pin 16 is just weak then what we may see is that the more devices we plug back in, in any order, the worse the signal looks.
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