File Allocation Table

FAT
Developer(s)	Microsoft, NCR, SCP, IBM, Compaq, Digital Research, Novell, Caldera
Full name	File Allocation Table
Variants	8-bit FAT, FAT12, FAT16, FAT16B, FAT32, ExFAT, FATX, FAT+
Introduced	1977 with Standalone Disk BASIC-80
Partition IDs	MBR/EBR: FAT12: 0x01 e.a. (Extended Attribute); FAT16: 0x040x060x0E e.a.; FAT32: 0x0B0x0C e.a.; BDP: EBD0A0A2-B9E5-4433-87C0-68B6B72699C7;
Structures
Directory contents	Table
File allocation	Linked list
Bad blocks	Cluster tagging
Limits
Max volume size	FAT12: 32 MB (256 MB for 64 KB clusters); FAT16: 2 GB (4 GB for 64 KB clusters); FAT32: 2 TB (16 TB for 4 KB sectors);
Max file size	4,294,967,295 bytes (4 GB − 1) with FAT16B and FAT32
Max no. of files	FAT12: 4,068 for 8 KB clusters; FAT16: 65,460 for 32 KB clusters; FAT32: 268,173,300 for 32 KB clusters;
Max filename length	8.3 filename, or 255 UCS-2 characters when using LFN
Features
Dates recorded	Modified date/time, creation date/time (DOS 7.0 and higher only),; access date (only available with ACCDATE enabled),; deletion date/time (only with DELWATCH 2);
Date range	1980-01-01 to 2099-12-31 (2107-12-31)
Date resolution	2 seconds for last modified time,; 10 ms for creation time,; 1 day for access date,; 2 seconds for deletion time;
Forks	Not natively
Attributes	Read-only, hidden, system, volume, directory, archive
File system; permissions	FAT12/FAT16: File, directory and volume access rights for read, write, execute, delete only with DR-DOS, PalmDOS, Novell DOS, OpenDOS, FlexOS, 4680 OS, 4690 OS, Concurrent DOS, Multiuser DOS, System Manager, REAL/32: execute with only FlexOS, 4680 OS, 4690 OS;; individual file / directory passwords not with FlexOS, 4680 OS, 4690 OS;; world/group/owner permission classes only with multiuser security loaded; ; FAT32: Partial, only with DR-DOS, REAL/32 and 4690 OS;
Transparent; compression	FAT12/FAT16: Per-volume, SuperStor, Stacker, DoubleSpace, DriveSpace; FAT32: No;
Transparent; encryption	FAT12/FAT16: Per-volume only with DR-DOS; FAT32: No;

File Allocation Table (FAT) is a file system developed for personal computers and was the default filesystem for MS-DOS and Windows 9x operating systems.^[3] Originally developed in 1977 for use on floppy disks, it was adapted for use on hard disks and other devices. The increase in disk drives capacity required four major variants: FAT12, FAT16, FAT32, and ExFAT. FAT was replaced with NTFS as the default file system on Microsoft operating systems starting with Windows XP.^[4] Nevertheless, FAT continues to be used on flash and other solid-state memory cards and modules (including USB flash drives), many portable and embedded devices because of its compatibility and ease of implementation.^[5]

^ Cite error: The named reference GB4 was invoked but never defined (see the help page).
^ Cite error: The named reference Microsoft_2006_ACCDATE was invoked but never defined (see the help page).
^ Bhat, W. A. (2010). "Review of FAT data structure of FAT32 file system". Oriental Journal of Computer Science and Technology. 3 (1): 161–164. S2CID 58178285.
^ "Comparing NTFS and FAT file systems". Microsoft. Archived from the original on 2016-06-20. Retrieved 2014-01-27.
^ "A brief introduction to FAT (File Allocation Table) formats". www.wizcode.com. Archived from the original on September 25, 2015. Retrieved September 24, 2015.

Cite error: There are <ref group=nb> tags on this page, but the references will not show without a {{reflist|group=nb}} template (see the help page).

[GB4-1] Cite error: The named reference GB4 was invoked but never defined (see the help page).

[Microsoft_2006_ACCDATE-3] Cite error: The named reference Microsoft_2006_ACCDATE was invoked but never defined (see the help page).

[:0-4] Bhat, W. A. (2010). "Review of FAT data structure of FAT32 file system". Oriental Journal of Computer Science and Technology. 3 (1): 161–164. S2CID 58178285.

[5] "Comparing NTFS and FAT file systems". Microsoft. Archived from the original on 2016-06-20. Retrieved 2014-01-27.

[6] "A brief introduction to FAT (File Allocation Table) formats". www.wizcode.com. Archived from the original on September 25, 2015. Retrieved September 24, 2015.

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