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

SiriusHardware · 11th Mar 2021, 8:19 pm

Mark, I think your suggestion, which is 'non invasive', is a good one and there is no harm in trying it before bringing the focus back onto the video RAM / output circuit if that proves necessary.

Just keep going for now and guide Colin through that process of following R/W. Maybe also look at the 'TV RAM R/W' signal emanating from UF6 pin 7, since that line only ever activates when the CPU is trying to write data into UF7 / UF8 through UE7 / UE8.

11th Mar 2021, 8:19 pm	#941
SiriusHardware Dekatron Join Date: Aug 2011 Location: Newcastle, Tyne and Wear, UK. Posts: 11,586	Re: Non-working Commodore PET 3016 Mark, I think your suggestion, which is 'non invasive', is a good one and there is no harm in trying it before bringing the focus back onto the video RAM / output circuit if that proves necessary. Just keep going for now and guide Colin through that process of following R/W. Maybe also look at the 'TV RAM R/W' signal emanating from UF6 pin 7, since that line only ever activates when the CPU is trying to write data into UF7 / UF8 through UE7 / UE8.