17 Apr
1999
17 Apr
'99
2:33 p.m.
The 6502 series ahd all sorts of undocumented opcodes and they tended to
change with later versions.
<THe 65xx stuff is quite known, but what has been new to my ears are the
<8085 'hidden' operations.
Those were more useful as the 8085 had some rather open holes in the
instruction set. The z80 also had a raft of them all commonly supported
though officially unofficial. and none were compatable with the 8085 hidden
ops (in either direction).
Allison