Re: 6502/65c02 undocumented opcode tables ...

[guertinp@IRO.UMontreal.CA (Paul Guertin)]

In article <324c7s$k6p@gap.cco.caltech.edu>,
nathan@cco.caltech.edu (Nathan Mates) writes:
>In article <3243kb$2t2@harbinger.cc.monash.edu.au>,
>Malcolm Herbert <mjher4@mdw058.cc.monash.edu.au> wrote:
>>I have heard that there is a table somewhere, listing all the 6502 (and
>>possibly the 65c02) undocumented opcodes ... all I know is that one of
>>them had been given the mnemonic of HCF -- Halt and Catch Fire, since
>>that's apparently the sort of thing it does to the CPU, throws it
>>completely out of whack ...
>
>   If you thinking of things where undefined opcodes did things like
>"decremet a, and if the result is 5, execute a hard reset", that's the
>domain of the 6510, used in the Commie 64 machines. Sorry, I don't
>have any specs; ask around.

The original 6502 also has undefined upcodes that do strange things.
For instance, $87 is "store the logical AND of A and X zero page".
There is a complete list of such opcodes in the March, 1981 issue
of Apple Assembly Line by Bob Sander-Cederlof. 

Paul Guertin
guertinp@iro.umontreal.ca