The datadisk was a great rack mount data transfer medium for Alesis products. Whenever you filled the 198 user spots to record patterns into for use in songs, you could just swap to another saved file on your datadisk and be ready to rock again. Run a different disk for every band, or every set, and you have enough space to spoil yourself with songs with fills and switches to mix it up and break that drum machine feel. The weakpoint is the floppy drive, which is not something you can source these days. When you see them starting to go, try to record all those drum tracks so you have a reference point for a future of your precious patterns and songs.