A friend of mine collects and restores old reel to reel tape drives. He recently showed me an Ampex 1080 (I'll have to double-check this model number) audio recorder capable of 3 3/4 minutes of recording time. Interestingly, this recorder uses a magnetic oxide covered mylar floppy disk of about 12" diameter which doesn't have a sleeve by the way (this disk puts the flop in floppy- it is extremely limp). Of course this is serial access and analog, but could IBM had been inspired by this unit? The recorder was a flop (pun intended) commercially. The operation and service manual are copyrighted 1965 and 1967. I looked for patent material on the original IBM floppy at their patent server as advertised on the list but didn't come up with anything on the first IBM floppy drive. Any info would be greatly apppreciated. Marty