 The number of root directory entries available for FAT12 and FAT16 is determined when the volume is formatted, and is stored in a 16-bit field.For a given number codice_3 and sector size codice_4, the number codice_5 of root directory sectors is codice_6, and codice_3 is normally chosen to fill these sectors, i.e., codice_8.FAT12 and FAT16 media typically use 512 root directory entries on non-floppy media.