Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!uunet!mcsun!i2unix!inria!chorus!opera!mir
From: mir@opera.chorus.fr (Adam Mirowski)
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Re: Floppy drives and differing formats
Message-ID: <7167@chorus.fr>
Date: 13 Dec 90 14:22:59 GMT
References: <5350@rex.cs.tulane.edu>
Sender: mir@chorus.fr
Reply-To: mir@opera.chorus.fr (Adam Mirowski)
Organization: Chorus systemes, Saint Quentin en Yvelines, France
Lines: 35

In article <5350@rex.cs.tulane.edu>, keating@rex.cs.tulane.edu (John W. Keating) writes:
%% Why hasn't anyone come up with a floppy disk that can read and write in both
%% IBM and Macintosh (and Amiga, and ...) formats?  Is the hardware so different
%% that no one even wants to attempt it, or is it a matter of proprietory
%% hardware?
%% 
%% On the same note, why hasn't a 5.25 inch drive been created for the IBM that
%% can read and write in both 360K and 1.2M formats correctly?
%% 
%% It seems to me as if a drive that can do these things would be in high demand.
%% 
%% John

Many people already did respond to the first question pointing to
new Mac drives, but maybe the author wanted a PC side solution.

Central Point Software manufactures an Copy II PC Option Board, which
can read/create unusual formats on 5.25" diskettes, bypass copy
protection etc. There could be a 3.5" version. Check with CPC.

The problem with 360Ko vs 1.2 Mo drives is that tracks are narrower
on 1.2 Mo diskettes; so are the heads. 1.2 Mo drives write narrower
tracks on 360 Ko diskettes, and if you use them to erase information
previously written by ordinary drives, only the middle of the wide
360-only-drive track will be rewritten.  If you try to read such a
diskette on a 360-only drive, its wide head will get confused by the
non erased information.

You don't want a variable geometry head in each 1.2 drive, do you?
Or two heads on both sides of the drive? Plus additional hardware
to drive the stepper motor?

-- 
Adam Mirowski,  mir@chorus.fr (FRANCE),  tel. +33 (1) 30-64-82-00 or 74
Chorus systemes, 6, av.Gustave Eiffel, 78182 Saint-Quentin-en-Yvelines CEDEX