When I got my first Apple II+ (a Brazilian clone) I didn't have money for a floppy drive, so I used cassettes extensively (I learned to... erm... backup games t

When I got my first Apple II+ (a Brazilian clone) I didn't have money for a floppy drive, so I used cassettes extensively (I learned to... erm... backup games to tape). By the sound of the tape you could identify code and bitmap segments, code being more random and data being more "rhythmic". Pattern recognition is a wonderful ability.