Here's the way Yamaha handles the gm/xg problem.
If you go to a music store who has the original S80 demo unit shipped from Yamaha, there is a gm sound set loaded on the smart media card shipped installed in every dealers demo unit. If the dealer loads these sounds into the internal memory, you can install a blank smart media card and save this setup to the card and then use it in your keyboard. If you install the XG plug in board, now you have the entire xg sound set on midi channels 17-32 of the S80/S30.
I have all the expansion cards in stock if anyone is interested.
George Kaye
Kaye's Music Scene
Reseda, California
818-881-5566