DOSFS Partition Table

Bill Knight BillK at rosw.com
Thu Feb 6 14:31:11 UTC 2003


  We just finished resolving some problems with a fat filesystem on a
CompactFlash card.  Some of the findings may be of help to you.  Also,
I am assuming the ATA card is very similar to the CompactFlash card in
its operation.  The information was gathered from an embedded system
running a different RTOS (RTEMS coming soon) and WinXP.

1) If the memory size of the card is large Windows may reformat it
FAT32 even if it was previously formatted FAT16 or FAT12.  This can be
overridden to a degree by selections in the drop-down boxes or via
command line options to the FORMAT command.

2) If hard sector 0 of the card is corrupted and Windows cannot tell
the card had been configured as an hard drive, it will be re-formatted
as a super floppy.  That is, the FAT boot sector will be placed at
hard sector 0.  The card will no longer have a Partition Table.  Just
guessing here but the following may be worth a try.  A utility like
Hex Workshop or sectedit might be used to read hard sector 0 from a
good card then write it back out to a corrupted one.  I have no idea
if utilities like FDISK will work on the cards as that utility is no
longer present in WinXP.

Hope this helps some.

-Bill Knight
R O SoftWare






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