I previously hinted at a hardware project I have been working on- an expansion bus adapter for the MC-10 allowing it to use EXORbus peripheral cards. The idea is pretty absurd as it the MC-10 is a little low-end consumer computer while EXORbus was typically used for pretty advanced industrial PLC or scientific computers. For instance, an EXORbus serial card would be quite expensive and have 8 ACIAs on it, giving you 8 serial ports, an insane amount for the lowly MC-10. My EXORbus Static RAM card has 1 MiB of RAM on it, also an insane amount for this little guy.
Since the EXORbus is made for 6800/6809 processors, and the MC-10's expansion bus is mostly just unbuffered signals from the mostly compatible processor, all we need is a bunch of buffers and connectors and a GAL to do address decoding into the MC-10's memory map. Here is the design I have been working on, yet to be prototyped:
I really wish I could have finished this during Retrochallenge, but I lost momentum with family events and vacations. Next time!
Someone is having way too much fun with the MC-10.
ReplyDelete:)
The 6803 in the MC-10 should be able to run a lot of the old 6800 stuff if you have the source code and can convert the I/O addresses.
Also, look for places it uses CPX as a pseudo-NOP for (cough) optimization. The fully flag-functional CPX on the 6801 will likely mess those pseudo-NOPs up. You can just put the hidden op-code in with a branch around (cost one byte, one cycle?). Or use the 6801's BRN for a real 2-byte NOP with arbitrary second byte.
It should be 10% or so faster.