I could be wrong about this, but I'll do my best to provide an answer.
There is no way to actually link your FD-8 to record on your PC's hard disc, if that's what you are referring to. You can, however, record on the FD-8 and then go from the RCA line out jacks into your computers sound card's LINE IN(or if the FD-8 and your sound card both have digital I/O, you can use them instead). From there your mixing options are obviously limited, but your songs will now be on your PC instead of the ZIP.
You could also use your FD-8 simply as an external mixer and buy multitracking software (such as N-Track, Cakewalk, Cubase, etc.) to record directly to the HD. If you want to do multiple tracks at one, you'll also need an interface such as the Event Gina or Darla. I don't think this is what you meant, but I figured I'd mention it anyway.
