Hi there I just formatted a Compact Flash Card using Windows 2000. With a little application I wrote, I'm now trying to read the entire content of the flash card, sector by sector, in order to understand the FAT structure as I want to be able to format the card myself using my application. However, when I read the content of the card, I dont understand why is that the first partition starts at sector 32? Why not at sector 0? I get this for every Flash Card I formatted. I read the Microsoft's Hardware White Paper on the FAT file system and it doesn't mention anything about this. Can anyone help me on that? Thanks alex

Try formatting under W9x as FAT16, I have found MSDOS is not able to recognise the FAT when formatted under W2K or XP !

Actually the file system I used was FAT16. Is there a difference if the card was formatted using Windows 2000 instead of Windows 9x, even if it's the same file system? Anyway, thanks for your help alex

Yes, I use a XP PC for work, but DOS is a hobby, I use Compact Flash media which is ATA66 compliant to transfer files, USB external card read/writer. If I formatted the CF media on XP it should be FAT16 as only 32MB, but DOS states the media is not formatted. If I format in DOS, XP will read and write OK. I tried this with a W2K PC with same result, though W9x did not cause any problems. http://support.microsoft.com/default.aspx?scid=kb;EN-US;310525

Alex: Your application starts reading at sector 32 because it is the first data sector. Partition and FAT are considered system areas and are not normally open to application access. Programs like Norton Utilities allow write access to these area after action by the user. You may access the system areas by using BIOS calls to access the disk. x86: XP writes a different media descriptor than DOS. Although the format is the same FAT12, DOS cannot read the XP version because it is not backwards compatible.