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From: psfales@ihlpl.UUCP (Peter Fales)
Newsgroups: net.micro.pc
Subject: Re: Reading/writing 360k diskettes on an AT (long)
Message-ID: <1444@ihlpl.UUCP>
Date: Tue, 28-Oct-86 15:05:51 EST
Article-I.D.: ihlpl.1444
Posted: Tue Oct 28 15:05:51 1986
Date-Received: Wed, 29-Oct-86 02:41:42 EST
References: <564@bucsb.bu.edu.UUCP> <273@puff.wisc.edu>
Organization: AT&T Bell Labs, Naperville, IL
Lines: 34

Subject: Re: Reading/writing 360k diskettes on an AT (long)
Newsgroups: net.micro.pc
References: <564@bucsb.bu.edu.UUCP> <273@puff.wisc.edu>

(Long article about 360K diskettes on a 1.2M AT drive deletetd)

Just to add another data point to the confusion, I have had almost no
problems swapping 360K disks between an AT&T PC-6300 and 6300+ (which
use the 360K and 1.2M drives respectively).  This is independant of
whether the diskette previously contained data written on either drive.
I have seen only a single case where data added to a 360K diskette by
a 1.2M  drive was unrecoverable on a 360K drive.

The author of the above article states

>     Most people will not have problems when swapping disks between drives
>     because the data on the disk is never overwritten (I'm talking
>     about DOS reusing clusters on the free list, NOT about updating
>     a file with an editor...)  Partially filling a disk with 360K stuff and
>     then adding some 1.2M stuff and reading it all back on a 360K drive 
>     should work.  In that case, you only cover cases 1 and 3 above.
> 

This is not correct because adding a file to the disk using a 1.2M drive
will still result in changes to the FAT and directory sectors which were
originally written with a 360K drive.  But as I said, I have had no
problems doing this.  However, for all the reasons given in this and
other articles DO NOT USE THIS METHOD WITH CRITICAL DATA.  As an easy
method of transferring data between machines, fine.  Keep in mind that
data on any part or all of the disk may become unreadable, so valuable
diskettes should not be swapped between the two types of drivess.

Peter Fales
ihnp4!ihlpl!psfales