Re: 6502 illegal opcodes

From: Segher Boessenkool <>
Date: Sat, 5 Nov 2011 19:47:53 +0100
Message-Id: <>
>>> not that
>>> ane #$00 is terribly useful =P
>> What is that, 8b?  Most people call that XAA afaik.
> yes :) and XAA is long "deprecated" imho, only ppl who know it from  
> the old
> broken lists call it like that =)

Which list do you recommend?  I find all of them quite broken.

>> (*) Oh and of course the STX abs,Y and STY abs,X (9e and 9c) insns,
>> those
>> are naughty!
> SHY and TAS you mean =)

SHY and SHX.  I simply call them STY and STX, because that is what they
_are_, they just have a little problem :-)  They weren't left out of the
opcode map "just because", right :-)

> those are which i ment - they work perfectly if you
> make sure nothing else tries to access the bus :) (and unlike ANE,  
> they are
> sometimes useful)

The only cycle where they run into trouble are the write cycle, they  
be influenced by the data bus, not RDY has no effect.  I think you mean
something else?


       Message was sent through the cbm-hackers mailing list
Received on 2011-11-05 19:00:12

Archive generated by hypermail 2.2.0.