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

SiriusHardware · 25th Feb 2021, 3:16 pm

Can I just check - when we say look at DA0 (etc) at the CPU socket we mean on the pins of the socket which is soldered into the PCB - not the one the CPU is plugged into on top.

If you were looking at DA0 on the CPU itself then it would be understandable to see a constant low bit '0', as that bit is low in the NOP opcode (EA = 1110 1010).

25th Feb 2021, 3:16 pm	#665
SiriusHardware Dekatron Join Date: Aug 2011 Location: Newcastle, Tyne and Wear, UK. Posts: 11,553	Re: Non-working Commodore PET 3016 Can I just check - when we say look at DA0 (etc) at the CPU socket we mean on the pins of the socket which is soldered into the PCB - not the one the CPU is plugged into on top. If you were looking at DA0 on the CPU itself then it would be understandable to see a constant low bit '0', as that bit is low in the NOP opcode (EA = 1110 1010).