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

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.

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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