[comp.sys.ibm.pc] Puzzling diskette format problem

peter@banyan.UUCP (Peter Grossman@Eng@Banyan) (01/11/90)

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?