No i mean file format as in how the binary data in the rom file is stored, and how it must be loaded (techie info). As for writting a program for mac, im writing RGD am i not, and thats for mac/linux and windows, so mac on its own shouldnt be a problem.
Data in ROMs of any variety are stored as binary data, and since space in ROMs is so limited, oftentimes the data is compressed and\or bit-packed*, making it very hard to actually
find text streams and data unless you know (a) exactly where to look in the ROM, and (b) what compression scheme was used to obfuscate the data.
Furthermore, it is likely that nearly every n64 game out there uses a different combination of tactics to squeeze all the data they need into their ROMs: one might store text strings between arrays of scripts, while another might store all of the text strings at the very end of the ROM, but use a dictionary compression scheme that pulls words in strings from other strings; so that modifying one string may inadvertently modify many others.
The best way to find where all the text is saved in the game is to step through the game's machine code at runtime, and look for a place from where the game reads a small amount of data from the ROM every time a new piece of text is shown.
I don't mean to discourage you, but just let you know what you're up against (to be honest, I've never looked at n64 roms looking for text, my experience with compressed strings and graphics comes from my study of SNES and GBA roms. It is
possible, though
unlikely, that the develoeprs of N64 roms chose to eschew all the compression routines they had learned over the past two generations, and they stored their strings in plaintext).
Good luck! =)
* (Diablo 2 had a similar problem: uncompressed, the amount of sprites in that game would have taken up
several gigs of hard drive space; therefore, all of the character sprites in Diablo 2 are compressed in a format that combines line-length encoding, 4bit/16 color bitpacking, and sequential buffer blitting. The space saving are
amazing; I wrote a program that could decode the *.DCC format so I could use Diablo 2's sprite for my upcoming game; I was astounded to learn that
the DCC format can squeeze over 447kb of uncompressed bitmaps into a 37.7kb DCC. Blizzard is absolutely
awesome).
