One of the very common problems with KIM-1 computers is that one or both custom programmed 6530 chips fails. They haven’t been made since the early 1980s and are basically impossible to find (not even eBay has them). Lots of people talked about making a replacement using the common 6532 and external EPROM, but nobody published a working circuit. After hundreds of hours of pointless searching, I finally decided to just design one and post it so anyone can use it.
My ugly breadboard:
I got it working and tested earlier today and am working on a PC board. The design is free for anyone to use, as will be the PC board design once done. I’ve only used it to replace 6530-002 (U2) but the design should work for the 003 device as well. If anyone uses it for 003 let me know.
Afternoon Update:
A PC board was finished and prototypes were ordered.