Re: 6502 disassembler

[Eric Smith <eric-no-spam-for-me@brouhaha.com>]

"Paul R. Santa-Maria" <paulrsm@buckeye-express.com> writes:
> You must give my disassembler at least one address of valid code to
> start with.  In my Monitor example, I told the disassembler to use the
> NMI, RESET, and IRQ pointers to valid code.
> 
> It traces the code.  Whenever it finds a JMP, JSR, or branch
> instruction, it saves the destination address in a list.
> 
> Whenever it finds a JMP, RTS, RTI, BRK, BRA, or illegal opcode it
> stops disassembling and gets an address from the destination list to
> continues disassembling.  When it needs another address but the list
> is empty, then it is done.  It goes back through all the data it
> collected and writes a disassembly listing to disk.

This is what I generally refer to as a "flow-tracing" disassembler.
I've written probably nearly a dozen of these over the years, including
a particularly complicated one for the Renesas (formerly Hitachi) SH
RISC processors.

I've spent some time enhancing and maintaining a flow-tracing
disassembler for the 6502 which was originally written by Robert Bond:
    http://www.brouhaha.com/~eric/software/dis6502/
It's written in C and tested on Linux, though it should be fairly
portable.