This ROM is put into the EDIT ROM socket in most PETs, and will test ROM, RAM, Keyboard, Video.

It works in machines that are otherwise playing dead due to bad lower RAM.
It requires at least a small part of the Kernal ROM to be alive.

It is compatible with PETs with discrete video logic, or with CRTC video logic.

It is not compatible with 6540-equipped PETs.
It is not compatible with PETs that are both 40-column AND equipped with a CRTC, such as 4032.

I am not the author of this excellent software. Please refer to the manual contained here.

This comes burned to a 27C16B EPROM, which is drop-in compatible with PET EDIT ROM sockets.