Date   : Thu, 17 Nov 1994 15:31:47 +0000
From   : lamcw <lamcw@...>
Subject: Undocumented Opcodes,

Nigel wrote:


;I seem to remember a thread about undocumented opcodes
;on the 6502, I wonder if I can get any information
;from:
;- -6502 data sheets, if anyone has these and they are any
;use I would appreciate them
;- -any other source

;I really need those undocumented ones!


yes indeed, undefined 6502 opcodes may eventually cause a
bigger headache than video interrupts.

i have 3 games which don't work - manic miner, match day and
repton2. i think repton 2 may be the easiest to crack out of
these 3. i'm sure in manic miner it uses these nasty opcodes
to 'decode' the game before execution... tricky.

there's the infamous 64doc which provides a lot of info about
these opcodes. there's also a list of them mailed to this group
a couple of months ago.


chris lam.