Yamaha U1 Silent - MacBook - compatible?

[jackrussel]

I got a new Yamaha U1, with silent function.

I managed to save a piece of music and to listen to it but I cannot get to save it on any USB key. The piano does seem to recognise there is a USB key but refuses to tranfer the data on to it.

I don't know if this a Mac, a USB or a Yamaha issue or all 3...

Does anyone use this Yamaha technology with a Mac?

Is Garageband U1 compatible?

Thanks for your help!

[quantum]

The USB key might need to be formatted by the piano first.  This will erase all data on the USB key, so back it up before you attempt a format. 

Is the piano saving as a standard MIDI file?  MIDI files would be compatible with many programs.