Technote used to carry the hard drives for the KN6500. That's where I got mine. Don't know if they still do. Haven't seen any used ones for sale. You might try doing an Internet search for KN6500 and accessories. Also, on the back of the keyboard there's a plug that you can plug a computer into. Then there's a switch that you can place in either midi or computer. I don't know how well this works, I've only used the connection on midi. There isn't much in the way of an explanation of how to use it in the manual, but toward the back of the manual there is a small paragraph about the connector and switch. Sorry I can't be of more help.