Path: utzoo!utgpu!watmath!clyde!att!alberta!ubc-cs!uw-beaver!cornell!mailrus!um-math!hyc
From: hyc@math.lsa.umich.edu (Howard Chu)
Newsgroups: comp.os.minix
Subject: Re: 68K minix
Message-ID: <495@stag.math.lsa.umich.edu>
Date: 27 Nov 88 10:04:42 GMT
References: <1600@ast.cs.vu.nl> <65@ausonics.OZ>
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Reply-To: hyc@math.lsa.umich.edu (Howard Chu)
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In article <65@ausonics.OZ> greyham@ausonics.OZ (Greyham Stoney) writes:
>As I understand it, The Mac uses a variable speed drive to pack as much on
>a 3 1/2" disk as everyone else can pack on using normal drives. Apparently
>this is a major problem in getting it to read/write anything but Mac disks.
>Anyone know more about this? Is there a program to read/write other format
>disks (say, IBM pc 720k?); if it were possible, someone would have done it by
>now.

On older style Macs, everything is software controlled. According to the
docs in _Inside_The_Macintosh_, the MacPlus drive controls its own speed,
independent of the Mac generated signal sent over the interface. As such,
unless someone can find docs for how to program the MacPlus floppy controller,
it'll be tough going. (That's the double sided floppy. I suppose no one is
really interested in using single sided floppies any more...?)

(The MacPlus hardware is described in Inside Macintosh, volume 4. The old
style Mac hardware is decribed in volume 3.) Too bad none of these volumes
really describe the hardware in enough detail. However, it mentions that
the disks are written in much the same way as the Apple II did, which implies
a non-standard signal encoding scheme...
--
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 /_ , ,_.                      Howard Chu
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