Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!bbn.com!aoa!rich
From: rich@aoa.UUCP (Rich Snow)
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Re: Any dual-head 360K/1.2M 5.25-inch floppy drives?
Summary: no problem.
Message-ID: <1569@aoa.UUCP>
Date: 24 May 91 14:55:08 GMT
Expires: 30 Jun 91 04:00:00 GMT
References: <1991May17.214849.3103@cs.ucla.edu>
Reply-To: rich@aoa.utrc.com (Rich Snow)
Distribution: usa
Organization: Adaptive Optics Assoc., Cambridge, Mass.
Lines: 24

In article <1991May17.214849.3103@cs.ucla.edu> wales@valeria.cs.ucla.edu (Rich Wales) writes:
>As anyone who has studied the issue will be aware, the recording head
>designs in 360KB and 1.2MB 5.25-inch floppy drives are different.  This
>means that the two types of drive are not totally compatible, even when
>dealing with low-density (360KB) diskettes.  (Specifically, a disk that
>has been formatted or written on by a 360KB drive cannot thereafter be
>reliably written on by a 1.2MB drive.)

I haven't seen this problem with any of the recent 1.2Meg drives. 
It is true that it occurred with the first generation of 1.2Meg drives.
I assume the positioning needed to be more accurate in order to assure
compatibility. It is quite a trick to double up the tracks in order to
make it compatible with 360K drives.

In fact, the new 'floptical' drives reliably read and write 360K format.
They get a greater track density by using an optical rather than purely
mechanical postioning system.

-Rich
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