The english link for that site is:
http://www.musitronics.de/indexe.html I'm not sure how such an installation would effect keyboard's warranty.
Also, there is no mention of Mac support, but I think it should work.
The USB interface is a great idea. Yamaha should have included it on the 9000. Unfortunately, the synth manufacturers are way behind the computer industry. Why are floppys even used anymore? If anything is built in, it should be at least a zip drive. And USB should have been on keyboards 2 years ago.
ell