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From: doner@aero.aero.org (John Doner)
Newsgroups: comp.sys.mac.misc
Subject: Re: Dead floppies
Message-ID: <95173@aerospace.AERO.ORG>
Date: 21 Dec 90 18:57:22 GMT
References: <10547@ilog.UUCP>
Sender: news@aerospace.aero.org
Reply-To: doner@aero.aero.org (John Doner)
Organization: The Aerospace Corporation
Lines: 23

In article <10547@ilog.UUCP>, skyvingt@ilog.UUCP (William Skyvington) writes:
|> The rate at which my floppies have been dying over the last year,
|> since I've been working on several IIcx machines, is outrageous.

I also often get floppy problems, although I can't say I've noticed an increase
over the last year.  Happlily, I find that the mere act of copying a disk with
CopyToMac usually resuscitates it, or at least enables me to recover files I
need.

When it comes up with disk error indications, I imagine this is due to flaws in
the media, leading to weak or nonexistent magnetic recording.  At any rate,
trying to read the disk sector by sector with FEdit will show specific sectors
that can't be read.  Sometimes an address mark will be invalid, costing it
a whole track.  Now I wonder: hard disk formatting includes identifying bad
or untrustworthy sectors so these get excluded from the volume map.  Isn't it
possible to do the same thing with floppies?  Is there a program out there
that will identify bad sectors and then render them inaccessible, perhaps by
putting small fake files over these areas of the disk, or tinkering with the
volume map.  BTW, many disks end up totally unreadable due to some sector in
the directory area being defective.  Under MFS, the directory could be located
anywhere on the disk.  Is this true of HFS also?

John Doner