AMPEX FLOPPY Circa 1965

From: William Donzelli <william_at_ans.net>
Date: Fri Jun 5 16:16:23 1998

> 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).

Another interesting way to form magnetic media was used by some dictation
machines - basically a closed loop of very wide tape, only a few inches in
diameter.

> Of
> course this is serial access and analog, but could IBM had been
> inspired by this unit?

Probably, but it also just seems like an obvious solution to a problem.

The floppy was invented for distributing new microcode for the
S/360s, and came into being just around 1970. The original design goal was
to make a low density portable disk, but it became apparent that they
could not make a flying head device cheaply. They settled for a floppy
medium, so the head could contact the slow moving disk without a problem.
One of the big design problems was to make the drives precise enough so
any drive could read any diskette, yet without the incredibly high quality
machining need for standard hard disks.

William Donzelli
william_at_ans.net
Received on Fri Jun 05 1998 - 16:16:23 BST