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Old 18th Mar 2021, 4:30 pm   #1148
SiriusHardware
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Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
Posts: 7,533
Default Re: Non-working Commodore PET 3016

Quote:
In post #1142 you are listing pairs of pin numbers, but only one trace is active in each scope capture.
The second pin in each line in #1142 is directly connected to the first pin in each line, that is, they are electrically the same place, hence only one scope trace per pair of pins.

Quote:
it does look correct that there would be some flicking of the signal between active and inactive.
In principle yes, but remember that we do not seem to be getting a buffer read enable signal for UI10/UI11 on their pins 1s, therefore those buffers will not be passing the system RAM content through to BD0-BD7. If we do see activity on BD0-BD7 it may therefore be other devices on the BD0-BD7 lines which are creating the periodic activity - the flat-line / inactive periods may be the very periods when we should be seeing the output from the system RAM.

Last edited by SiriusHardware; 18th Mar 2021 at 4:49 pm.
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