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From: peter@banyan.UUCP (Peter Grossman@Eng@Banyan)
Newsgroups: comp.sys.ibm.pc
Subject: Puzzling diskette format problem
Summary: DS/DD bad formats (reserved sectors=0)
Message-ID: <683@banyan.UUCP>
Date: 11 Jan 90 15:56:07 GMT
References: <21990002@hpvcfs1.HP.COM> <25A51804.9795@maccs.dcss.mcmaster.ca> <355@marvin.moncam.co.uk>
Reply-To: peter@banyan.UUCP (Peter Grossman@Eng@Banyan)
Organization: Banyan Systems, Inc.
Lines: 1
Sender:Peter@banyan.com
Keywords:diskette format reserved sectors

I have a very strange problem when I format a ds/dd diskette in my B drive (360k).  Under DOS 3.31 on either and PC/AT (339) or a CompuAdd AT clone I most often create diskettes that are unreadable elsewhere.  When I analyzed the problem I discovered that one byte is being incorrectly written in the boot sector.  This is byte hex 14 which is the lower half of the "# reserved sectors" word.  It is set to zero sometimes!  This byte, as far as I can tell, should never be zero since it implies that there is no





 boot sector!  Norton Disk Doctor easily corrects the problem and I can create the same symptoms by zeroing this byte on a well formatted diskette.  What have I done? I ran IBM's virus scan program which reported no problems.  This has been an annoying problem for many months.  Does anyone have ideas?