Disklavier

Hello all -- I joined this group in the hope someone might be able to
help me figure out how to convert the songs on a Smart PianoSoft disk
I purchased from their current proprietary format to MIDI files. I'd
read online that this should be possible and had downloaded a
converter program. However, when the disk arrived, I couldn't read it
in my PC. Further reading would indicate it's a 720K diskette format
and that I might need an old IBM PC in order to run software that
would let me read it? I don't own a Disklavier but I'm desperately
trying to get sheet music for one of the songs on the disk (since that
sheet music isn't available any other way). If anyone could help me
figure out how to do this, I'd really appreciate it. Once I have the
MIDI file, I should be able to print sheet music using Cakewalk. Thanks.