here is some info of PSR-S900 and PSR-S700
http://www.musicpascher.com/boutique/yamaha+psr+s700+psrs700-p-3425.html

http://www.musicpascher.com/boutique/yamaha+psr+s900+psrs900-p-3426.html


[This message has been edited by andre159 (edited 04-01-2007).]