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From: rob@kaa.eng.ohio-state.edu (Rob Carriere)
Newsgroups: comp.sys.atari.st
Subject: Booting
Summary: You can boot from disk, safely.
Keywords: booting, disk integrity
Message-ID: <378@accelerator.eng.ohio-state.edu>
Date: 10 Jul 88 22:32:50 GMT
Sender: news@accelerator.eng.ohio-state.edu
Reply-To: rob@kaa.eng.ohio-state.edu (Rob Carriere)
Organization: Ohio State Univ, College of Engineering
Lines: 21

There have been several recent posting in this newsgroup to the effect
that booting from a floppy is dangerous, that a HD might damage the
data if started from an unparked state etc.

I don't think so.
Reason:  It takes a digital circuit at most a couple of hundred
microseconds to complete any power-up state races.  In the case of the
hard disk or a 5.25 floppy, the rw heads are removed from the media by
means of a spring.  This effect has to be overcome before anything can
happen; this a mechanical phenomenon, it will take milliseconds.  In
the case of the 3.5 floppy, this device first has to slide open the
door on the disk before it can even start to think about lowering the
heads onto the media.  If you listen during power-up, you will notice
that there is a pause of about a second before the disk door slides
open.

In summary, by the time the rw heads get to the point where they could
do damage, the control circuitry has long since settled down.  If
there are problems, this reflects either a design error in the hard_
and or software, or a transient glitch.

Rob Carriere