FAT16

Noun

 * 1)  The version of the FAT series of file systems which uses a 16-bit file allocation table.
 * 2)  The original version of this file system, storing both the number of (real or virtual) disk sectors and the number of sector clusters in a volume as 16-bit integers.
 * 3)  FAT16B, the version of this file system storing the number of clusters in a volume as a 16-bit integer but using a 32-bit integer to represent the total number of sectors in a volume, allowing for larger volume and file sizes.