This 6502 CPU NOP tester will provide you with a way of quickly testing for a functional CPU. While it doesn’t provide in-depth testing of the CPU it does offer a simple way to test for basic functionality.
With the potentiometer, you can adjust the clock slightly.
You can also detect 6502C – “Sally” chips. The NOP tester has a tactile switch labeled “Sally”, when pressing this switch, the /HALT line that is available on the Sally CPU’s is brought low which will turn off all the LED’s and the CPU will be halted.
There are also jumpers (J1, J2) that are there to provide functionality for testing W65C02 chips.
The 6502 NOP tester is part of a series of NOP testers developed by Stephan at 8bit-museum.de. I am selling these here with his permission where a portion of the proceeds will go to him. More information such as documentation and gerber files can be found here.