MS-DOS: Determining the FAT Size for a DISK

ID Number: Q38110

3.20 3.21 3.30 3.30a 4.00

MS-DOS

Summary:

The File Allocation Table (FAT) size for a volume (disk partition) is

determined by the number of clusters contained in the volume. If the

number of clusters contained in a volume is 4086 or greater, MS-DOS

uses a 16-bit FAT. Otherwise, a 12-bit FAT is used.

Other methods will work with versions of MS-DOS prior to 3.3x;

however, the method described above should be used for compatibility

with present and future versions of MS-DOS.