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From: lester@suphys.physics.su.OZ.AU (K R Lester)
Newsgroups: comp.sys.acorn
Subject: Mac Drives
Message-ID: <1991Jun12.073638.16119@metro.ucc.su.OZ.AU>
Date: 12 Jun 91 07:36:38 GMT
Article-I.D.: metro.1991Jun12.073638.16119
Sender: news@metro.ucc.su.OZ.AU
Reply-To: lester@suphys.physics.su.OZ.AU (K R Lester)
Organization: School of Physics, Uni of Sydney, Australia.
Lines: 23
Nntp-Posting-Host: physics.su.oz.au

As regards Mac drives, I am under the perhaps mistaken impression that
the drives are nonstandard. I believe that apple actually changes the
speed of rotation based on the position of the head from the axis of
rotation, this allows them to keep the data desity roughtly constant
i.e. store more on the outer tracks where the track circumference is longer. 

I suppose that it is possible to simulate this to some extent in software
by changing the number of sectors per track according to the track number.

This info may of course be wrong but Apple does have a long track record
(no pun intended :-) ) of doing their own thing as far as disk drives
(and computers, interfaces etc) are concerned

	Kim

--
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					I
lester@physics.su.oz.au			I  DOS - the original computer virus.
Kim Lester:  Dept. High Energy Physics, I
		Sydney University,	I  OS/2 on PS/2 - half an operating
		Down Under		I          system on half a computer.
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