30 Oct
2001
30 Oct
'01
4:32 a.m.
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.
doubtful
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.
NOPE!
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.