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

SiriusHardware · 21st Jan 2021, 11:46 pm

Do I take it that RDY is an input only? It just has one 1K pullup resistor and the rest of the track heads off to one of the connections on the expansion connector and apparently no-where else.

The track between R14 and the CPU pin 2 is quite long and on the top side so it will be worth looking to see if it, or the connection between CPU pin 2 and that track, are open circuit.

Next thing would be to see if pin 2 has a low resistance to 0V with power off and / or whether the voltage on that socket pin comes up to +5V with the CPU removed.

SYNC goes nowhere except to the expansion connector.

21st Jan 2021, 11:46 pm	#206
SiriusHardware Dekatron Join Date: Aug 2011 Location: Newcastle, Tyne and Wear, UK. Posts: 11,560	Re: Non-working Commodore PET 3016 Do I take it that RDY is an input only? It just has one 1K pullup resistor and the rest of the track heads off to one of the connections on the expansion connector and apparently no-where else. The track between R14 and the CPU pin 2 is quite long and on the top side so it will be worth looking to see if it, or the connection between CPU pin 2 and that track, are open circuit. Next thing would be to see if pin 2 has a low resistance to 0V with power off and / or whether the voltage on that socket pin comes up to +5V with the CPU removed. SYNC goes nowhere except to the expansion connector.