6502 CPU NOP Tester – Bare PCB (DIY Retro Hardware Tool)

Bring your 6502 CPU to life with this bare PCB NOP Tester – a simple yet powerful tool for hobbyists who love working with classic processors. Perfect for testing, learning, and displaying the inner workings of one of the most iconic CPUs in computing history.

🔹 Designed by the creator of the Retro Chip Tester Pro – offered here with his permission.
🔹 Bare PCB only – you’ll source your own parts and CPU (BOM and build details available online).
🔹 Surplus boards from my last order – I’m selling these at cost + postage.
🔹 Hands-on hobbyist project – easy to assemble with standard components.

How it works:
The NOP tester hardwires the data lines to the NOP (No Operation) opcode. This causes the 6502 to continuously execute NOP instructions while incrementing the program counter. Eight LEDs on the board display the lower address lines, so you can actually watch the CPU “count” in real time – a fantastic educational and diagnostic tool!

Great for:

• Retro computing enthusiasts

• Electronics tinkerers and learners

• CPU collectors who want a way to see their chips in action

👉 Looking for a Z80 CPU NOP tester PCB? Check my other listing: https://www.ebay.com.au/itm/236072891958