> It looks awfully like 8080 or Z80 code, to be honest, though I could be
> wrong.

If the opening part is a jump table (as was suggested) it would appear that
the processor stores jump addresses in big-endian format (MSB first).  If
memory serves, the Z80 and 8080 are little-endian, which would rule them
out.  Unfortunately, I just looked up the 68HC05 and 68HC11 and it doesn't
appear to be either of those, nor is it the 8x51.  Maybe a National Cop8
[running out of ideas...]