Hi Joe When I was back at Intel, I was responsible for the test used by the system test on the UPP units. I can tell you a little bit about them. First, I have no idea what a "upgraded the RAM memory" means. These used 4002's. These work on the 4004/4040 bus. They are completely incompatable with other types of RAM's and they also have input ports on them ( or maybe it was output but I think it was inputs ). The internal orginization is not compatable with ordinary RAM's either( not a simple power of two type addressing ). The main controller board has a 4040 uP with some ROM ( 4001's ). This ROM was addressed as bank0. Each of the two slots for the personality cards was addressed as Bank0 for slot 0 and Bank1 for slot 1. This way, personality code could be accessed on either bank to run the particular operation. The code on the controller board ran the handshake with the parallel port to the Intelec system. I wish that I'd saved the schematics I'd had at Intel but I was not as smart then. I'd also made a board that I'd plugged into a Intelec system in place of the 4040. It allowed me to test the hardware and compare ROM code to make sure every thing was correct. This is also long gone. I once even had the ROM code for these. Dwight that's dead. .