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Can anybody help?
I need information on some FATs.I have the relivant information on FAT16,FAT32,NTFS but I'am after some of the more out there FATs ie ADFS etc,..

Another point has anybody tried the following.
The O/S I'am designing loads all of the relivant information (in theory) but has all of the FATs that can be used loaded as seperate files.
Is this a bad idea :-/
Grateful for any input..

I don't understand exactly what you're saying..
What do you mean by loading a FAT as a separate file?
I can mail you the sources of my FAT16 driver, if you want..

I think Jay's got his terminology mixed up. "FAT" refers to the MS-DOS FAT file system (of which FAT12, FAT16 and FAT32 are variants). FAT, NTFS, ADFS etc. are all file systems.

I'm still not sure what you mean by "all of the FATs that can be used loaded as seperate files" though.

What I'am trying to convey is that NTFS, FAT32 has its own structure, for example file name, extensions, date, time, etc,... When the O/S boots up it could search through a directory for a list of files that has the data and/or code that the O/S needs to analyse and use to save and load files from the harddrive. So in theory to extended the capabilties of the file systems that the O/S could use, a new file with the right information could be stored in the relivent directory for use. Sometimes I'am no that good at explaning myself.
  I hope this clears up any miss understanding.

So you're talking having file system drivers, like you'd have device drivers. Windows NT, at least, has been doing this for some time: I have fastfat.sys and ntfs.sys on my Windows 2000 box, and some time ago I would have had hpfs.sys too. The M?bius does this too: it uses GRUB to load the boot drivers it needs from a disk supported by GRUB, and it can use these disk and file system drivers to load the rest of the system.

My home-built OS (floppy only) is about ten years old. I originally only had a FAT and no Root (files were called as #1, #2, #3, etc.) My fat was just the Starting sector for the file. As each sector was read the last two bytes of the sector told the OS where to find the next sector. In '98 I did a full re-write of original code and used the FAT12 file system and added a root directory. I relocated the original FAT to a "FILE" and gave it a name. That way I could use either my original system or the standard FAT12 which gave me portability to my other computers.

The same could be done for FAT12, FAT16, FAT32 ...etc. Just write a short utiluity to save the current file system and relocate the saved file to the "FAT" location. CAUTION!! There is a problem with this. If you modify a file while using FATXX then change to another system the saved root/fat will not be updated. Your OS would have to modify both FAT versions for every disk 'write' operation.

The better way would be to use separate partitions with different file systems. ie.. Linux, FAT16, HPFS or in your case  FAT16, FAT32, NTFS.......

Juddley