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Date: Sat, 17 Jun 1995 06:20:49 +1000
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199506162020.GAA00687@godzilla.zeta.org.au>
To: aflundi@sandia.gov, freebsd-hackers@freebsd.org
Subject: Re: HD Geometry dirty trick
Sender: hackers-owner@freebsd.org
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>> The BIOS can invent any geometry that it wants (subject to the
>> constraints 1 <= nsectors <= 63, 1 <= nheads <= 256, 1 <= ncyls <= 1024).

>Does this mean that it's possible that every distinct
>BIOS could produce a different geometry for a given disk
>drive, so that there is no way to predict via an algorithm
>for all machines what the BIOS geometry should be?  Bummer!

Yes.  It makes /etc/disktab unusable.  However, it's much
easier to find out the drive at runtime than to keep a huge
table of disk drives.

Bruce