6502 NOP Generator adapter

This is a 6502 NOP generator adapter which in useful for troubleshooting a faulty 6502 computer.

The 6502 NOP generator has the datalines hard wired so that the 6502 will continually execute the NOP instruction and thereby cause the address lines to pulse.

This is useful when troubleshooting a 6502 computer. You can use a logic probe or oscilloscope to easily check the address lines and decoding logic.  (see last photo for an example of what it looks like in the Commodore PET)

The adapter board also had additional LEDs to show the status of theRDY, IRQ, NMI and RESET lines.

Includes:

– 1 x Assembled 6502 NOP Generator Adapter (The 6502 CPU is not included in the sale and only included in the last photo for reference)

I have used these adapters for repair many Commodore PET computers.

You will need a fully working 6502 CPU in order to use this adapter.

Take care when inserting the 6502 CPU into the adapter and make sure the pins align and the CPU has the correct orientation. Also make sure the adapter is inserted correctly into the motherboard being  tested.

If the motherboard under test has the 6502 CPU directly soldered to the board then you will need to remove it and replace with a socket. Do not attempt this if you do not have the required soldering skills as you can easily damage the tracks on these old retro computers.