UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Non-working Commodore PET 3016

Mark1960 · 17th Mar 2021, 7:26 pm

I think the hope is that by looking at each pair of inputs and outputs on the buffers we can see a problem on one of the data lines. Then by comparing that data line with the buffer control signals to determine if its the buffer failing to drive correctly or one of the two ram chips. Then from the ram control lines which of the two ram chips on that data line.

A ram test rom would probably help a lot. Its going to be difficult to capture ram access on the scope as the pet software is not going to be making regular access to ram.

17th Mar 2021, 7:26 pm	#1099
Mark1960 Octode Join Date: Mar 2020 Location: Kitchener, Ontario, Canada Posts: 1,297	Re: Non-working Commodore PET 3016 I think the hope is that by looking at each pair of inputs and outputs on the buffers we can see a problem on one of the data lines. Then by comparing that data line with the buffer control signals to determine if its the buffer failing to drive correctly or one of the two ram chips. Then from the ram control lines which of the two ram chips on that data line. A ram test rom would probably help a lot. Its going to be difficult to capture ram access on the scope as the pet software is not going to be making regular access to ram.