RAM/ROM Replacement and Debug console for 6502-based computers
June 14, 2021 – New orders are paused because of a high level of interest over the last couple of days (thank you!)
Please join the waitlist below if you are interested in the ROMulator.

Out of stock



June 13, 2021 – Thanks everyone for the interest in the ROMulator! Due to the recent interest, I now have more orders than I can fill within the next few weeks. For the moment, I need to pause new orders until I can determine the best way to source the required parts to meet existing orders.

If you are interested in the ROMulator, please send your email address using the contact form below and I will add you to a waitlist. As soon as new stock is available I will contact you. Thank you very much!

The ROMulator is a RAM and ROM replacement and diagnostic board for the Commodore PET, Apple II, and other 6502 based microcomputers. The ROMulator connects to the 6502 socket in your computer, and the ROMs to use are selected by a dip switch on the board. It allows you to view the memory of a running 6502 machine using the replacement RAM by halting the CPU and sending the memory contents over an SPI connection to a Raspberry Pi.

The ROMulator is open source, and the schematics and Verilog code for the ROMulator’s onboard FPGA are available at:

Check out my video using the ROMulator to help fix a PET 2001-N here: