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Romhacking => Programming => Topic started by: Bob789 on September 30, 2017, 12:56:23 pm

Title: Best Assembler/Disassembler
Post by: Bob789 on September 30, 2017, 12:56:23 pm
Hello,

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.
Title: Re: Best Assembler/Disassembler
Post by: Psyklax on September 30, 2017, 01:45:32 pm
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.
Title: Re: Best Assembler/Disassembler
Post by: Bob789 on September 30, 2017, 06:36:56 pm
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
Title: Re: Best Assembler/Disassembler
Post by: nesrocks on September 30, 2017, 11:34:57 pm
The Mesen emulator also has a great way of writing assembly code directly into the rom.
Title: Re: Best Assembler/Disassembler
Post by: horst on October 15, 2017, 01:38:03 am
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 http://www.romhacking.net/utilities/627/ (http://www.romhacking.net/utilities/627/)
FCEUXD SP can be grabbed here http://www.the-interweb.com/serendipity/index.php?/categories/9-FCEUXD-SP (http://www.the-interweb.com/serendipity/index.php?/categories/9-FCEUXD-SP)

Since I haven't used an assembler to reassemble the reverse engineered ROM so far, I have no recommendation on that.
Title: Re: Best Assembler/Disassembler
Post by: SleepyFist on October 16, 2017, 07:06:05 pm
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.
Title: Re: Best Assembler/Disassembler
Post by: Dracula X on October 16, 2017, 07:17:58 pm
I use:

Assembler's:
ASL - Cross Assembler
ASM6F

Disassembler's:
disasm6

That's it!