This tester allows you to perform a quick test of a 6502 CPU to determine if the chip is likely to be good or is faulty or fake.
It does this by presenting a permanent "NOP" (No Operation) instruction on the data pins of the device under test so that it will step through all the 64k addresses in sequence if it is not faulty or fake. The progress is displayed by the LED's.
More information is contained in this PDF document.
