Path: utzoo!utgpu!watmath!clyde!bellcore!rutgers!tut.cis.ohio-state.edu!bloom-beacon!bu-cs!mirror!rayssd!raybed2!linus!mbunix!jcmorris
From: jcmorris@mitre-bedford.ARPA (Joseph C. Morris)
Newsgroups: comp.sys.ibm.pc
Subject: Re: 3.5" disk drives and diskettes
Summary: 1.44 mb on a DD disk works (so far)
Message-ID: <42531@linus.UUCP>
Date: 7 Dec 88 22:19:07 GMT
References: <10208@watdragon.waterloo.edu>
Sender: news@linus.UUCP
Reply-To: jcmorris@mbunix (Morris)
Organization: The MITRE Corporation, McLean, VA.
Lines: 29

In a recent article jjboritz@violet.waterloo.edu (Jim Boritz) writes:
>
>In the new world of 3.5" floppies the high density diskettes have an
>additional hole on the side opposite the protect hole.  My 3.5" drive will
>not even think about formatting at 1.44Meg unless this hole is present.  My
>question is, "Can I punch holes in my 720K diskettes and use them at
>1.44Meg?"  
>
Punching a hole through the plastic is dangerous: you might crack the plastic
shell in the process, but more seriously you will be generating plastic
debris where it could contaminate the disk surface and/or the heads on the
drive you insert it into.  Agreed that the prices for HD diskettes are
a ripoff, but there is a simpler way: cripple the circuit in your drive which
tests for the extra hole.

I've routinely (usually by accident) formatted DD disks to 1.44 mb and
have never had any problems with bad sectors.  (I make it a point, however,
to use HD disks if they will be stored for some time,  so I can't speak to
the long-term storage characteristics.)  I use Verbatim and Sony disks.

Neither the PS/2-50's or PS/2-70's I've used made any complaint about
formatting the disks to 1.44 mb.  The only problem I've had is in 
getting the disks re-formatted back down to 720K.

Hint: some formatters won't change the density once the disk has been
formatted at 720K or 1.44 mb.  If this happens, it can be fixed by 
beginning a format run, then suddenly removing the disk from the drive.
Brute-force, but it avoids having to get a copy of Norton if one isn't
handy.