The MC10 is based on the 6803 and the 6847. The 6803 is a 6800 with extra i/o and instructions. The MC10 firmware uses the extra instructions often. I used a 6811 assembler and made a file that assembles but I have not checked to output against a known-good file.
I'm currently more interested in my other 6803-based project, for which I have a board that I wish to get running.