NES Disassembly

[Maximum Potion]

What do you guys use when you disassemble a nes rom?
I've tried several programs like dasm6502 and dcc6502 but the window closes immediately after opening it. So, I dragged the rom into the .exe and it scrolled through the rom saying there were invalid opcodes and then closes right after.
It doesn't make a .asm or anything.

Any help?

[Reaper man]

do you even know assembly?

[Maximum Potion]

Not really, but I have had some success with it before.
The difference there was that the file was already disassembled.

[Reaper man]

well, in any program, there's code, and data. It sounds like you were trying to disassemble data, instead of code (hence the invalid opcode errors). Find where the code is first, then go from there. Also, try reading up on the disassembler documentation so that you know how to use it properly.