Today I started playing around with this EPROM PCB I recently got.
Before I do anything I needed to change a decoupling capacitor that has had its legs almost completely pulled out of the body.
The silkscreen says the EPROM’s should be 27C1000’s. I used 27C010’s as they are the same pinout.
27C1000 chips are 8 bit so the data must be split across 2 EPROM’s.
I looked for a rom 256KB in size and deinterleaved it into HI and LO files. Then burnt them onto the EPROM’s.
After taking a 50/50 chance on which way round these EPROM’s went (and getting it wrong) I found that the LO side goes on the bottom row of sockets and the HI on the upper rom.
I fired the thing up and…..
Now was also a good opportunity to test out my conversion of that old CK2605 PLA into a GAL22V10.
All good here too.
Quite satisfied with that. If only the new Angry Birds conversion would fit onto it.
Still have to do some testing and see what those DIP switches are used for