I'm sorry but I won't be able to give you the size of the wave rom. Yamaha is keeping this information to themselves for the time being. Because of their ability to compress their samples as most companys do and do it with such great results, they say the size in actual numbers, may not be understood by most and therefore this figure will not be given out. Needless to say, their sample library is quite good!
I suggested that with 1 GB of user sample memory, Yamaha could give their customers some pretty amazing additional sample sounds to load into the Tyros 2

George Kaye
Kaye's Music Scene
Reseda, California