[PETERg0rsq]

Have you checked the PROM inputs are all switching and confirmed if the PROM outputs are switching?

PSU for PROM can fail.

Is your PROM on-board, or on the digital board? If on the digital board the connecting cable could be a problem.


I have only had two PROMs fail in about 15 units.

I had manufactured some EPROM boards a few years ago. They were only intended for my own use though. I will need to review them before I could offer one.

My board replaces the PROM, the multiplexer, the level converters and the logic gates. I cant remember if I re-programmed the EPROM to just fire three outputs High, LOW and MIDDLE directly from the inputs, so I need to re-visit what I actually did.

My MK1 replacement board was a PIC PROM simulator which also worked well.

I have also just moved from Windows machine to Linux, so have to see if I can get my EPROM programmer to work.

Also need to get KiCad working again!