> Hi, > I've built a disassembler for the NES roms to test the 6502 cpu of my nes > emulator. However the disassembler showed many FF opcodes (mostly chained in > long groups of FF op's). I used other NES disassemblers to compare the output so > to rule out errors and I also looked at the binary data directly. So I would > like to know why there are so many FF opcodes in Nes roms (e.g. zelda, SMB2, > Ninja Gaiden)? > > Thanks >
It's not an opcode -- it's just meaningless data you're looking at. Long runs of 0xFF usually mean that part of the ROM has not been programmed with anything.
---- Bart
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