Hy!

I don't know that keyboard but those drives are usualy the same as those in computers. So it is either 720kb disk drive or 1,44Mb disk drive. If it is 720kB drive, it's gonna be a hard way to get one because no one uses them any more. But 1,44Mb drive you can buy in any computer store. But first talk to your servicer or send mail to Yamaha support what kind of drive is in your PSR-SQ16.

Kosta