Emu XL-7 & MP-7 User's Group

I just ran across an error (forgot to record it) but it said my pattern
could not be saved.  Last I checked I had 67% memory left.  .  .  Then it
asks if I want to compact data.  This isn't in the manual, but should I be
"compacting" more often?  Looks like it's fine now.  What does this do?
anyone??