Re: The first xy

[TBaehr@xxxxxxxx]

Tom Hawley: "5.25's might well be more robust in this regard although I've not seen any
published data."

I'm no engineer, but given the size and the data density, my guess is that there was simply more
magnetic material in the larger disks and therefore the recorded signal's decay had smaller
consequences. The high-density disks of both the 5.25 and 3.5 inch disks were of the same material
as the low-density disks; an extra hole or notch identified them as high-density. The difference was
that the high-density disks came from batches that passed certain tests. For a while, you could buy
(at least for the 3.5 disks) a little gizmo that would punch the extra hole in low-density disks.
Reformat them at 1.44MB, and voila - a HD disk. Sorta. The idea was that you wouldn't use them for
mission-critical storage - at least until repeated uses proved them reliable.

Disk prices eventually plummeted, making this kind of cost-saving unnecessary. Besides, most of us
had enough free AOL disks to keep us well supplied.

Tim Baehr