Technics supplied a standard hard drive for the KN3000 which was a simple slot in, and called the keyboard so equipped KN3500 in some markets.

Keysoft sold a new board which I remember swapping my hard drive from the Technics board to the Keysoft board and soldering several fine wires to tiny surface mount pads (this normally done only by Technics approved service centres but I had special dispensation). I was the only person in the UK with this system at that time.

It had a parallel interface, special cable, and associated computer program as described above by Harry G. This enabled backup and editing of the KN3000 hard drive on the pc or laptop, with more saving locations, naming characters and facilities than the standard Technics hard drive.