*BSD News Article 20572


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From: adam@veda.is (Adam David)
Newsgroups: comp.os.386bsd.misc,comp.os.386bsd.development
Subject: Re: AMIFS? (was: Re: BSD UNIX)
Message-ID: <CD02sM.E3D@veda.is>
Date: 7 Sep 93 20:12:08 GMT
References: <SWILDNER.93Sep4145521@channelz.GUN.de> <1993Sep7.163857.19661@fcom.cc.utah.edu>
Organization: Veda Systems, Iceland
Lines: 21

terry@cs.weber.edu (A Wizard of Earth C) writes:

>Note that the MAC is similarly handicapped, but is even more variable than
>the Amiga -- it may be possible to read Amiga disks on the MAC without a
>great deal of trouble, but reading MAC disks on an Amiga or PC without
>better hardware will be impossible (the MAC can write disks that other
>machines can read, but doesn't by default).

This is true for 800kB Mac disks, they are GCR encoded and have 5 different
storage density zones. The Mac hardware deals with this by having the drive
spin at variable speeds. Others have successfully accessed the disks spinning
at a constant speed by varying the data transfer rate, usually requiring
extra hardware.

1600kB Mac disks are normal, with 20 sectors per track and 80 tracks per disk
surface. With suitably written filesystem code (possibly needing improvements
to the *BSD-i386 floppy driver), such Mac disks (high density) could be
mounted on the *BSD filesystem tree.

--
adam@veda.is