Have a board here with subject chip on it. Also has 2 IMP-00A's. I assume what I have is the 8 bit version of the IMP-16. Haven't been able to locate instruction set for this 8 bit version. All the data sheet says is "CROM's which implement 8-bit instruction sets are available as standard products." Seems to be lots of info out there for IMP-16 but anyone heard of this IMP-8A/521D? Thanks, Bill