This is not a real instruction in the 65c02 processor; I invented it for
the sole purpose of handling the specialized logic that is performed by
BIT in IMM mode. To be fair--I can imagine this really _was_ implemented
as a "separate" instruction on the chip! But I don't know that for sure.
Regarding soft switches, we had several we should have been listening
for on both reads and writes, but were only doing so on writes; this is
now fixed.
Regarding statuses, we were incorrectly calculating both carry and
overflow. This should now be fixed, although some quick examinations of
disassembly output suggest there is something else amiss. Debugging will
continue shortly.