hard-sector 5 1/4 disk

From: Fred Cisin <cisin_at_xenosoft.com>
Date: Tue Oct 30 12:32:24 2001

> I do know that lots of drive controllers use the index hole of
> soft-sectored disks to time the disk's rotation in order to determine
> which type drive is running on it.

although some use it for a "drive not ready" signal.

> 92/180/320/720k disks rotate at 300rpm
> and 'high-density' drives like 77track 8' hd and your standard 1.44mb
> floppy drives rotate at 360rpm.

8" is 360RPM

"normal" 5.25" is 300 RPM

"high density" ("1.2M") 5.25" thinks that it is an 8" and is at 360RPM
(SOME switch speeds when doing 360K in a 1.2M, SOME (such as IBM!) rely on
a change in the data transfer rate)

3.5" 1.4M (I have NEVER seen a 1.44M format!) are also at 300RPM

> Some drives by other makers run at odd
> speeds. Atari 8-bit drives generally run at 288rpm and this makes a
> difference esp when reading copy-protected disks.

And some, such as Weltec, operate at half of "normal" speed (180 RPM) in
order to handle "high density" with "normal density" data transfer rates.
Received on Tue Oct 30 2001 - 12:32:24 GMT

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