Emulator source code (Stella or Z26, not PCAE) will reveal most of what you
need to know. However, I have found that even these emulators don't do all
of the exotic opcodes (in particular, neither seems to do RRA, which I tried
to use in one of my games.)
Other than that, my source of info for my superoptimizer was these pages:
This page gives info on what each opcode does (but note that the mnemonics
on this page are different from dasm's)
http://www.ffd2.com/fridge/docs/6502-NMOS.extra.opcodes
and this page had detailed info on a few weird opcodes and uses the same
mnemonics as dasm. Also it has some cycle-by-cycle information, including
2-byte operations that take 8 cycles... might be useful for something.
ftp://ftp.funet.fi/pub/cbm/documents/chipdata/64doc
>From: Adam Wozniak <adam@xxxxxxxxxxxxxxxx>
>Reply-To: stella@xxxxxxxxxxxxxxxxxx
>To: stella@xxxxxxxxxxxxxxxxxx
>Subject: Re: [stella] Games using unofficial opcodes
>Date: Wed, 1 Jun 2005 13:23:01 -0400
>
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>On Wed, 1 Jun 2005, Dennis Debro wrote:
> > I looked at this and I think it uses one by accident. It does a jmp to
> > LF01F which would cause the sax (opcode $83) instruction to be called.
> > They could have jmp'd to LF021 (which is the Veritcal Sync routine)
>which
> > would have bypassed this and the game would have worked the same.
>
>Is there a good complete opcode reference that includes all the
>undocumented
>instructions?
>
>http://www.s-direktnet.de/homepages/k_nadj/opcodes.html
>pro: discusses undocumented opcodes
>con: difficult to search, doesn't list status flags affected succinctly
>
>http://www.6502.org/tutorials/6502opcodes.html
>pro: hyperlinks for easy navigation
>con: no undocumented opcodes, doesn't list status flags affected succinctly
>
>http://members.chello.nl/taf.offenga/illopc31.txt
>pro: lists alternate names for undocumented opcodes
>con: doesn't list status flags affected succinctly
>
>http://www.xmission.com/~trevin/atari/6502_opcodes.html
>pro: big chart has lots of information
>con: difficult to read, doesn't list status flags succinctly
>
>http://www.oxyron.de/html/opcodes02.html
>pro: nice charts, status flags affected are listed
>con: descriptions are terse, unclear which opcodes are not available on
>6502
>
>http://axis.llx.com/~nparker/a2/opcodes.html
>pro: nice charts, nice explanation of how opcodes are decoded
>con: few english descriptions
>
>Is there a web page somewhere that combines the best of all these?
>One geared for atari 2600 programmers?
>
>- --
>adam@xxxxxxxxxxxxxxxx http://cuddlepuddle.org/~adam
>KG6GZR http://cuddlepuddle.org/~adam/resume.html
>
>
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