I'm working on adding a debugger for my emulator, and was hoping to add some "source level" debugging. This requires the debugger having access to the symbols and source code you are trying to debug, and I was wondering if anyone has tried this before. Is there a standard way for the assemblers used to store symbol information? If not, what is the most popular development environment and I can target that. Thanks for the help.

Are you trying to debug the EXE or the NES ROM image running on your emulator (6502 CPU emulation assembly)?

Sorry, should have been more clear. I want to debug the ROM image (6502 assembly). Ideally this would be used as a development platform for the NES, allowing a game author to debug his homebrew ROM with the source and symbols.

I've been looking into that stuff also, but don't seem to find a lot of info on it. I've thought about using CA65's format, but it doesn't seem to be well documented.

hydesprojects.cjb.net

I did some looking into this. CA65 (part of the CC65 tool suite) seems to be a pretty good assembler. The .DEBUGINFO control command(-g on command line) seems to add symbols to the output object file. When this object file is linked, a .lbl label file is created which contains the symbols. So what I'm proposing is to have my debugger load symbols from the .lbl file, and display them in the disassembly. This way people using the CA65 assembler to develop NES programs will be able to debug in a more readable format. Does this sound reasonable? Any other toolchains that people would rather see supported besides CA65?