I came up with a random idea for a programming project - a program that monitors your score.dat for a Touhou game and fills in a checklist of "achievement"-type things(like "1CCed hard with all characters" and such). Problem is, I can't figure out what anything in the score.dat file represents, since whenever I change anything and try to run the program, the checksum resets and all the scores are erased. Using Touhou 6 as a test dummy, mind you.
Would anyone happen to know how the score.dat files are put together? I haven't hacked anything more advanced than Super Nintendo roms, so checksums and encryption are familiar but I wouldn't know what to do with them.