Disklavier

Hello,

I have a Mark II Disklavier with a broken 720 KB floppy drive.  First
I thought I could simply replace the floppy drive with a new one. 
Then I learned that they cost about $300 and still require the crappy
720 KB floppies.  Then I heard about the magical DSR1 box that allows
us to "upgrade" our Mark II to use "normal" 1.44 MB floppy disks, but
according to the Yamaha spokesperson I talked with today, the DSR1 was
discontinued about a year ago.  I couldn't find any used DSR1s for
sale online.  Furthermore, she said that Yamaha won't have a
replacement for the DSR1 until a year from now.

So... I am thinking a good alternative at this point would be to use
my Mac laptop with a UX16 MIDI interface adapter to control the
Disklavier.  My needs are simple: I want the ability to "record" piano
pieces onto my Mac and then have them play back on the piano with the
real life key movements.  Basically I just want the functionality that
I had with my old 720 KB floppy disks, but using my computer hard
drive instead.

Is there such a program for the Mac OS X operating system that will do
the trick?  I understand the Mark II uses "ESEQ" files, but I'm not
sure if that matters if I do the recording and playback via the MIDI
interfaces.

Any thoughts/recommendations?  I am happy to pay for a nice little
piece of software to get the job done.

Thanks,
Bill