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Best Assembler/Disassembler

Started by Bob789, September 30, 2017, 12:56:23 PM

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I would like to know what the preferred assembler/disassembler is for 6502 NES Assembly. It does not need to be one program, multiple programs would work fine.
I'm looking for these tools for Windows or DOS.


For NES hacking, you can't get better than FCEUX. Has a great debugger, I've hacked and translated numerous NES games already using it.


I've used the FCEUX debugger a bit and it seems like a great tool. I plan on using it for my hacks. However, I was also looking for a tool
that could disassemble so that I could change the assembly code if possible.

EDIT: I now realize what I just said. FCEUX would be an adequate tool for assembly. However, I would not mind like options


The Mesen emulator also has a great way of writing assembly code directly into the rom.


I do not know what is best but what works generally very well if you wanted to reverse engineer code is a combination of static and dynamic analysis techniques (disassembly and debugging). For disassembly, I used IDA Pro and several additions (loaders, plugins) that enabled it to load NES ROM dumps and to export symbols into a format that could be loaded into the FCEUXD SP debugger. This allows for comfortable side-by-side analysis of the code with names etc. exported from IDA visible in the debugger.

The tools for IDA are available here
FCEUXD SP can be grabbed here

Since I haven't used an assembler to reassemble the reverse engineered ROM so far, I have no recommendation on that.


I'm using NESASM3, probably not the best but it's the one I'm used to at this point, I've also set up batch scripts to help me assemble and test a bit more rapidly, nothing fancy.

Dracula X

I use:

ASL - Cross Assembler


That's it!
Back to Thunder Force II hacking again.