File Allocation Table or FAT is a computer file system
File system
In computing, a file system is a method for store and organize computer files and the data they contain to make it easy to find and access them.... architecture now widely used on most computer systems and most memory cards, such as those used with digital cameras.
William Henry "Bill" Gates III is an United States business magnate, philanthropist, author, the List of the 100 wealthiest people , and chairman of the board of Microsoft, the software company he founded with Paul Allen.... and Marc McDonald
Marc McDonald
Marc B. McDonald is an United States who was Microsoft's first salaried employee . He is credited with designing the File Allocation Table for Standalone Basic which was the file system for the MS-DOS operating system and Microsoft Windows.... during 1976–1977.
It is the primary file system for various operating systems including DR-DOS
DR-DOS
DR-DOS is a DOS-type operating system for IBM PC-PC compatible personal computers, originally developed by Gary Kildall's Digital Research and derived from CP/M-86.... , OpenDOS
OpenDOS
OpenDOS is a freeware DOS-like and MS-DOS-compatible operating system.It was originally Digital Research's DR-DOS. Shortly after the release of DR-DOS 6, Digital Research was acquired by Novell, who rebranded the product Novell DOS.... , FreeDOS
FreeDOS
FreeDOS is an operating system for IBM PC compatible computers. FreeDOS is made up of many different, separate programs that act as "packages" to the overall FreeDOS Project.... , MS-DOS
MS-DOS
MS-DOS is an operating system commercialized by Microsoft. It was the most commonly used member of the DOS family of operating systems and was the main operating system for personal computers during the 1980s.... , OS/2
OS/2
OS/2 is a computer operating system, initially created by Microsoft and IBM, then later developed by IBM exclusively. The name stands for "Operating System/2," because it was introduced as part of the same generation change release as IBM's "IBM Personal System/2 " line of second-generation personal computers.... (v1.1) and Microsoft Windows
Microsoft Windows
Microsoft Windows is a series of software operating systems and graphical user interfaces produced by Microsoft. Microsoft first introduced an operating environment named Windows in November 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces .... (through Windows Me
Windows Me
Windows Millennium Edition, or Windows Me , is a hybrid 16-bit/32-bit graphical operating system released on 14 September 2000 by Microsoft.... ).
For floppy disk
Floppy disk
A floppy disk is a data storage medium that is composed of a disk of thin, flexible magnetic storage medium encased in a square or rectangle plastic shell.... s, it has been standardized as ECMA
Ecma International
'Ecma International' is an international, private non-profit standards organization for information and communication systems. It acquired its name in 1994, when the European Computer Manufacturers Association changed its name to reflect the organization's international reach.... -107 and ISO
International Organization for Standardization
The International Organization for Standardization , widely known as ISO , is an international standard-setting body composed of representatives from various national standards organizations.... /IEC
International Electrotechnical Commission
The International Electrotechnical Commission is a Non-profit organization, non-governmental international standards organization that prepares and publishes International Standards for all electrical, electronic and related technologies ? collectively known as "electrotechnology".... 9293.
Discussion
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A software developer is a person or organization concerned with facets of the software development process wider than design and coding, a somewhat broader scope of computer programming or a specialty of project manager including some aspects of Software product management....
Microsoft Corporation is a multinational corporation computer technology corporation that develops, manufactures, licenses, and supports a wide range of computer software products for computing devices....
Compaq Computer Corporation was an United States personal computer company founded in 1982, and is now a brand name of Hewlett-Packard Company.... DOS 3.31)
Windows 95 is a consumer-oriented graphical user interface-based operating system. It was released on August 24, 1995 by Microsoft, and was a significant progression from the company's previous Microsoft Windows products.... OSR2)
A master boot record , or partition sector, is the 512-byte boot sector that is the first disk sector of a Disk partitioning data storage device such as a hard disk.... )
A master boot record , or partition sector, is the 512-byte boot sector that is the first disk sector of a Disk partitioning data storage device such as a hard disk.... )
A master boot record , or partition sector, is the 512-byte boot sector that is the first disk sector of a Disk partitioning data storage device such as a hard disk.... ) EBD0A0A2-B9E5-4433 -87C0-68B6B72699C7 (GPT
GUID Partition Table
In computer hardware, Globally Unique Identifier Partition Table is a standard for the layout of the partition table on a physical hard disk. It is a part of the Extensible Firmware Interface standard proposed by Intel as a replacement for the IBM PC BIOS, one of the few remaining parts of the original IBM PC.... )
In computer science, a linked list is one of the fundamental data structures, and can be used to implement other data structures. It consists of a sequence of node s, each containing arbitrary data Field s and one or two reference s pointing to the next and/or previous nodes....
Gigabyte is an SI prefix-multiple of the unit byte for Computer data storage. Since the giga- prefix means 109, gigabyte means 1,000,000,000 bytes .... minus 1 byte (or volume size if smaller)
In computer file systems, a cluster is the unit of disk space allocation for files and directories. In order to reduce the overhead of managing on-disk data structures, the filesystem does not allocate individual disk sector, but contiguous groups of sectors, called clusters.... count
4,077 (212-19)
65,517 (216-19)
268,435,437 (228-19)
Max filename size
8.3 filename, or 255 UTF-16 characters when using LFN
Long filename
Long filenames , spelled "long file names" by Microsoft Corporation, are Microsoft's way of implementing filenames longer than the 8.3 filename, or short-filename, naming scheme used in Microsoft DOS in their modern File Allocation Table and NTFS filesystems....
Gigabyte is an SI prefix-multiple of the unit byte for Computer data storage. Since the giga- prefix means 109, gigabyte means 1,000,000,000 bytes ....
Gigabyte is an SI prefix-multiple of the unit byte for Computer data storage. Since the giga- prefix means 109, gigabyte means 1,000,000,000 bytes .... with 64k clusters (not widely supported)
A terabyte is a measurement term for computer storage. The value of a terabyte based upon a decimal radix is defined as one 1000000000000 bytes, or 1000 gigabytes....
A terabyte is a measurement term for computer storage. The value of a terabyte based upon a decimal radix is defined as one 1000000000000 bytes, or 1000 gigabytes.... (with 32KB clusters)
Features
Dates recorded
Creation, modified, access (accuracy to day only) (Creation time and access date are only available when LFN support is enabled)
In computer file systems, a fork is additional data associated with a file system object. A file system might support only one fork per file or might support multiple named forks....
The archive bit is a binary bit. As such, it is either 1 or 0, also frequently called set and clear or reset . It represents whether the file has or has not changed since the last backup....
Most modern file systems have methods of administering permissions or access rights to specific user and groups of users. These systems control the ability of the users affected to view or make changes to the contents of the file system....
Stac Electronics was an engineering company founded in 1983 by seven friends at Caltech. Originally headquartered in Pasadena, California, California and later in Carlsbad, California, California, the company developed interesting hardware and software technology, but struggled financially, until the release of Stacker disk compression softwa... , DoubleSpace
DoubleSpace
DoubleSpace is a disk compression utility supplied with MS-DOS starting from version 6.0. The purpose of DoubleSpace was to increase the amount of data the user could store on disks, by transparently compressing and decompressing data on-the-fly.... , DriveSpace
DR-DOS is a DOS-type operating system for IBM PC-PC compatible personal computers, originally developed by Gary Kildall's Digital Research and derived from CP/M-86....
No
File Allocation Table or FAT is a computer file system
File system
In computing, a file system is a method for store and organize computer files and the data they contain to make it easy to find and access them.... architecture now widely used on most computer systems and most memory cards, such as those used with digital cameras.
William Henry "Bill" Gates III is an United States business magnate, philanthropist, author, the List of the 100 wealthiest people , and chairman of the board of Microsoft, the software company he founded with Paul Allen.... and Marc McDonald
Marc McDonald
Marc B. McDonald is an United States who was Microsoft's first salaried employee . He is credited with designing the File Allocation Table for Standalone Basic which was the file system for the MS-DOS operating system and Microsoft Windows.... during 1976–1977.
It is the primary file system for various operating systems including DR-DOS
DR-DOS
DR-DOS is a DOS-type operating system for IBM PC-PC compatible personal computers, originally developed by Gary Kildall's Digital Research and derived from CP/M-86.... , OpenDOS
OpenDOS
OpenDOS is a freeware DOS-like and MS-DOS-compatible operating system.It was originally Digital Research's DR-DOS. Shortly after the release of DR-DOS 6, Digital Research was acquired by Novell, who rebranded the product Novell DOS.... , FreeDOS
FreeDOS
FreeDOS is an operating system for IBM PC compatible computers. FreeDOS is made up of many different, separate programs that act as "packages" to the overall FreeDOS Project.... , MS-DOS
MS-DOS
MS-DOS is an operating system commercialized by Microsoft. It was the most commonly used member of the DOS family of operating systems and was the main operating system for personal computers during the 1980s.... , OS/2
OS/2
OS/2 is a computer operating system, initially created by Microsoft and IBM, then later developed by IBM exclusively. The name stands for "Operating System/2," because it was introduced as part of the same generation change release as IBM's "IBM Personal System/2 " line of second-generation personal computers.... (v1.1) and Microsoft Windows
Microsoft Windows
Microsoft Windows is a series of software operating systems and graphical user interfaces produced by Microsoft. Microsoft first introduced an operating environment named Windows in November 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces .... (through Windows Me
Windows Me
Windows Millennium Edition, or Windows Me , is a hybrid 16-bit/32-bit graphical operating system released on 14 September 2000 by Microsoft.... ).
For floppy disk
Floppy disk
A floppy disk is a data storage medium that is composed of a disk of thin, flexible magnetic storage medium encased in a square or rectangle plastic shell.... s, it has been standardized as ECMA
Ecma International
'Ecma International' is an international, private non-profit standards organization for information and communication systems. It acquired its name in 1994, when the European Computer Manufacturers Association changed its name to reflect the organization's international reach.... -107 and ISO
International Organization for Standardization
The International Organization for Standardization , widely known as ISO , is an international standard-setting body composed of representatives from various national standards organizations.... /IEC
International Electrotechnical Commission
The International Electrotechnical Commission is a Non-profit organization, non-governmental international standards organization that prepares and publishes International Standards for all electrical, electronic and related technologies ? collectively known as "electrotechnology".... 9293. Those standards include only FAT12 and FAT16 without long filename
Long filename
Long filenames , spelled "long file names" by Microsoft Corporation, are Microsoft's way of implementing filenames longer than the 8.3 filename, or short-filename, naming scheme used in Microsoft DOS in their modern File Allocation Table and NTFS filesystems.... support; long filename
Long filename
Long filenames , spelled "long file names" by Microsoft Corporation, are Microsoft's way of implementing filenames longer than the 8.3 filename, or short-filename, naming scheme used in Microsoft DOS in their modern File Allocation Table and NTFS filesystems.... s with FAT is partially patent
Patent
A patent is a set of exclusive rights granted by a state to an inventor or his assignee for a term of patent in exchange for a disclosure of an invention.... ed.
The FAT file system is relatively straightforward technically and is supported by virtually all existing operating system
Operating system
An operating system is an interface between hardware and applications; it is responsible for the management and coordination of activities and the sharing of the limited resources of the computer.... s for personal computer
Personal computer
A personal computer is any general-purpose computer whose original sales price, size, and capabilities make it useful for individuals, and which is intended to be operated directly by an end user, with no intervening computer operator.... s. This makes it an ideal format for solid-state
Solid-state drive
A solid-state drive is a data storage device that uses Solid-state Computer storage to store persistent data. An SSD emulates a hard disk drive interface, thus easily replacing it in most applications.... memory card
Memory card
A memory card or flash memory card is a solid-state electronic flash memory data storage device used with digital cameras, Personal Digital Assistant and Mobile computers, telephones, music players, video game consoles, and other electronics.... s and a convenient way to share data between operating system
Operating system
An operating system is an interface between hardware and applications; it is responsible for the management and coordination of activities and the sharing of the limited resources of the computer.... s.
Microsoft BASIC was the foundation product of the Microsoft company. It first appeared in 1975 as Altair BASIC, which was the first BASIC programming language available for the Altair 8800 hobbyist microcomputer.... . In August 1980 Tim Paterson
Tim Paterson
Tim Paterson is an United States computer programmer, best known as the original author of MS-DOS, the most widely used operating system in the 1980s.... incorporated FAT into his 86-DOS operating system for the S-100
S-100 bus
The S-100 bus, IEEE696-1983 , was an early computer bus designed in 1974 as a part of the Altair 8800, generally considered today to be the first personal computer .... 8086 CPU boards; the file system was the main difference between 86-DOS and its predecessor, CP/M
CP/M
CP/M is an operating system originally created for Intel 8080/Intel 8085 based microcomputers by Gary Kildall of Digital Research. Initially confined to single tasking on 8-bit processors and no more than 64 kilobytes of memory, later versions of CP/M added multi-user variations, and were migrated to 16-bit processors.... .
The name originates from the usage of a table which centralizes the information about which areas belong to files, are free or possibly unusable, and where each file is stored on the disk. To limit the size of the table, disk space is allocated to files in contiguous groups of hardware sectors
Disk sector
In the context of computer disk storage, a sector is a subdivision of a Track on a magnetic disk or optical disc. Each sector stores a fixed amount of data.... called cluster
Cluster (file system)
In computer file systems, a cluster is the unit of disk space allocation for files and directories. In order to reduce the overhead of managing on-disk data structures, the filesystem does not allocate individual disk sector, but contiguous groups of sectors, called clusters.... s. As disk drives have evolved, the maximum number of clusters has dramatically increased, and so the number of bits used to identify each cluster has grown. The successive major versions of the FAT format are named after the number of table element bits: 12, 16, and 32. The FAT standard has also been expanded in other ways while preserving backward compatibility with existing software.
FAT12
The initial version of FAT is now referred to as FAT12. Designed as a file system for floppy diskettes, it limited cluster addresses to 12-bit values, which not only limited the cluster count to 4078, but made FAT manipulation tricky with the PC's 8-bit and 16-bit registers. (Under Linux, FAT12 is limited to 4084 clusters.) The disk's size is stored as a 16-bit count of sector
Cylinder-head-sector
Cylinder-head-sector, also known as CHS, was an early method for giving addresses to each physical block of data on a hard disk drive. In the case of floppy drives, for which the same exact diskette medium can be truly disk formatting to different capacities, this is still true.... s, which limited the size to 32 MB
Megabyte
Megabyte is a SI prefix-multiple of the unit byte for digital information computer storage or transmission and is equal to 106 bytes.... . FAT12 was used by several manufacturers with different physical formats, but a typical floppy diskette at the time was 5.25-inch, single-sided, 40 track
Cylinder-head-sector
Cylinder-head-sector, also known as CHS, was an early method for giving addresses to each physical block of data on a hard disk drive. In the case of floppy drives, for which the same exact diskette medium can be truly disk formatting to different capacities, this is still true.... s, with 8 sectors per track, resulting in a capacity of 160 KB
KB
The abbreviation KB or kb can refer to:*Kilobit , a unit of information used, for example, to quantify computer memory or storage capacity... for both the system areas and files. The FAT12 limitations exceeded this capacity by a factor of ten or more.
By convention, all the control structures were organized to fit inside the first track, thus avoiding head movement during read and write operations, although this varied depending on the manufacturer and physical format of the disk. At the time FAT12 was introduced, DOS did not support hierarchical directories, and the maximum number of files was typically limited to a few dozen. Hierarchical directories were introduced in MS-DOS
MS-DOS
MS-DOS is an operating system commercialized by Microsoft. It was the most commonly used member of the DOS family of operating systems and was the main operating system for personal computers during the 1980s.... version 2.0.
A limitation which was not addressed until much later was that any bad sector in the control structures area, track 0, could prevent the diskette from being usable. The DOS formatting tool rejected such diskettes completely. Bad sectors were allowed only in the file area, where they made the entire holding cluster unusable as well. FAT12 remains in use on all common floppy disks, including 1.44MB
Megabyte
Megabyte is a SI prefix-multiple of the unit byte for digital information computer storage or transmission and is equal to 106 bytes.... ones.
Initial FAT16
In 1984, IBM released the PC AT, which featured a 20 MB hard disk. Microsoft introduced MS-DOS 3.0 in parallel. (The earlier PC XT was the first PC with a hard drive from IBM, and MS-DOS 2.0 supported that hard drive with FAT12.) Cluster addresses were increased to 16-bit, allowing for up to 65,517 clusters per volume, and consequently much greater file system sizes, at least in theory. However, the maximum possible number of sectors and the maximum (partition
Disk partitioning
Disk partitioning is the dividing of the data storage space of a hard disk drive into separate areas referred to as partitions. A partition editor program can be used to create, delete or modify these partitions.... , rather than disk) size of 32 MB did not change. Therefore, although technically already "FAT16", this format was not what today is commonly understood as FAT16. With the initial implementation of FAT16 not actually providing for larger partition sizes than FAT12, the early benefit of FAT16 was to enable the use of smaller clusters, making disk usage more efficient, particularly for small files (which were more common at the time than they are today, after the 1990s). Also, the introduction of FAT16 actually did bring an increase in the maximum partition size under MS-DOS, since the implementation of FAT12 for hard disks in MS-DOS 2.0 was limited to 15 MB. (That is, the initial FAT16 did not support larger drives than FAT12, but MS-DOS 3.0 using FAT16 did support larger drives than MS-DOS 2.0 using FAT12, by a factor of two.)
A 20 MB hard disk formatted under MS-DOS 3.0 was not accessible by the older MS-DOS 2.0. (This was because MS-DOS 2.0 did not support version 3.0's FAT-16 and because it did not support hard disk partitions over 15 MB in size.) Of course, MS-DOS 3.0 could still access MS-DOS 2.0 style 8 KB-cluster partitions.
MS-DOS 3.0 also introduced support for high-density 1.2 MB 5.25" diskettes, which notably had 15 sectors per track, hence more space for the FATs. This probably prompted a dubious optimization of the cluster size, which went down from 2 sectors to just 1. The net effect was that high density diskettes were significantly slower than older double density ones.
Extended partition and logical drives
Apart from improving the structure of the FAT file system itself, a parallel development allowing an increase in the maximum possible FAT size was the introduction of multiple FAT partitions. Originally partitions were supposed to be used only for sharing the disk between operating systems, typically DOS and Xenix
Xenix
Xenix is a version of the Unix operating system, licensed by Microsoft from AT&T in the late 1970s. The Santa Cruz Operation later acquired exclusive rights to the software, and eventually began distributing it as SCO UNIX.... at the time, so DOS was only prepared to handle one FAT partition. It was not possible to create multiple DOS partitions using DOS tools, and third party tools would warn that such a scheme would not be compatible with DOS. Simply allowing several identical-looking DOS partitions could lead to naming problems: should C: be the first FAT partition on disk, for simplicity, or rather the partition marked as active in the partition table, so that several DOS versions can co-exist? And which partition should be C: if the system was booted from a diskette?
To allow the use of more FAT partitions in a compatible way, a new partition type was introduced (in MS-DOS 3.2, January 1986), the extended partition, which is a container for additional partitions called logical drives. Originally only one logical drive was possible, permitting hard disks up to 64 MB. In MS-DOS 3.3 (August 1987) this limit was increased to 24 drives, equal to the maximum number of available letters for drive names (A and B being reserved for the first two floppy drives, at least one of which many, if not most, systems of the era were equipped; where only one was installed, B always simulated a second drive using A.) Logical drives are described by on-disk structures which closely resemble the Master Boot Record
Master boot record
A master boot record , or partition sector, is the 512-byte boot sector that is the first disk sector of a Disk partitioning data storage device such as a hard disk.... (MBR) of the disk (which describes the primary partitions), likely to simplify the implementation. Though some believe these partitions were nested in a way analogous to Russian matryoshka doll
Matryoshka doll
A matryoshka doll, a Babushka doll or a Russian nested doll, also called a stacking doll, is a set of dolls of decreasing sizes placed one inside the other.... s, that isn't the case. They are stored as a row of separate blocks within a single box; these blocks are often referred to as being chained together, by the links in their extended boot record (EBR) sectors. Only one extended partition is allowed. Under MS-DOS, logical drives are not bootable, and the extended partition can only be created after the primary FAT partition, which removes all ambiguity but also eliminates the possibility of booting several DOS versions from the same hard disk. (A few systems other than MS-DOS can boot logical drives, and partitions can be created in any order using third party formatting tools.)
A useful side-effect of the extended partition scheme was to significantly increase the maximum number of partitions possible on a PC hard disk beyond the four which could be described by the MBR alone.
Prior to the introduction of extended partitions, some hard disk controllers (which at that time were separate option boards, since the IDE standard did not yet exist) could make large hard disks appear at the hardware (or BIOS?) interface level as two separate disks.
Compaq Computer Corporation was an United States personal computer company founded in 1982, and is now a brand name of Hewlett-Packard Company.... DOS 3.31 (an OEM version of MS-DOS 3.3 released by Compaq with their machines) introduced what is today called the FAT16 format, with the expansion of the 16-bit disk sector count to 32 bits. The result was initially called the DOS 3.31 Large File System. Although the on-disk changes were minor, the entire DOS disk driver had to be converted to use 32-bit sector numbers, a task complicated by the fact that it was written in 16-bit assembly language
X86 assembly language
x86 assembly language is the family of backwards-compatible assembly languages for the x86 class of processors, which includes Intel's Pentium series and AMD's Athlon series.... .
In 1988 the improvement became more generally available through MS-DOS 4.0 and OS/2
OS/2
OS/2 is a computer operating system, initially created by Microsoft and IBM, then later developed by IBM exclusively. The name stands for "Operating System/2," because it was introduced as part of the same generation change release as IBM's "IBM Personal System/2 " line of second-generation personal computers.... 1.1. The limit on partition size was dictated by the 8-bit signed
Signedness
In computing, signedness is a property of variables representing numbers in computer programs. A numeric variable is signed if it can represent both negative and non-negative numbers, and unsigned if it can only represent positive numbers.... count of sectors per cluster, which had a maximum power-of-two value of 64. With the standard hard disk sector size of 512 bytes, this gives a maximum of 32 KB clusters, thereby fixing the "definitive" limit for the FAT16 partition size at 2 gigabyte
Gigabyte
Gigabyte is an SI prefix-multiple of the unit byte for Computer data storage. Since the giga- prefix means 109, gigabyte means 1,000,000,000 bytes .... s. On magneto-optical media, which can have 1 or 2 KB sectors, the limit is proportionally greater.
Windows NT is a family of operating systems produced by Microsoft, the first version of which was released in July 1993. It was originally designed to be a powerful high-level-language-based, processor-independent, multiprocessing, multiuser operating system with features comparable to Unix.... increased the maximum cluster size to 64 KB by considering the sectors-per-cluster count as unsigned. However, the resulting format was not compatible with any other FAT implementation of the time, and it generated greater internal fragmentation
Fragmentation (computer)
In computer storage, fragmentation is a phenomenon in which storage space is used inefficiently, reducing storage capacity. The term is also used to denote the wasted space itself.... . Windows 98
Windows 98
Windows 98 is a graphical operating system released on 25 June 1998 by Microsoft and the successor to Windows 95. Like its predecessor, it is a hybrid 16-bit application/32-bit application monolithic product based on MS-DOS.... also supported reading and writing this variant, but its disk utilities did not work with it.
The number of root directory entries available is determined when the volume is formatted, and is stored in a 16-bit signed field, defining an absolute limit of 32767 entries (32736, a multiple of 32, in practice). For historical reasons, FAT12 and FAT16 media generally use 512 root directory entries on non-floppy media. Other sizes may be incompatible with some software or devices (entries being file and/or folder names in the original 8.3 format). Some third party tools like mkdosfs
Mkdosfs
mkdosfs is used to create an MS-DOS file system under Linux on a device .... allow the user to set this parameter.
Long file names
One of the user experience goals for the designers of Windows 95
Windows 95
Windows 95 is a consumer-oriented graphical user interface-based operating system. It was released on August 24, 1995 by Microsoft, and was a significant progression from the company's previous Microsoft Windows products.... was the ability to use long filename
Long filename
Long filenames , spelled "long file names" by Microsoft Corporation, are Microsoft's way of implementing filenames longer than the 8.3 filename, or short-filename, naming scheme used in Microsoft DOS in their modern File Allocation Table and NTFS filesystems.... s (LFNs—up to 255 UTF-16 code points long), in addition to classic 8.3 filenames. LFNs were implemented using a work-around
Workaround
A workaround is a bypass of a recognized problem in a system. A workaround is typically a temporary fix that implies that a genuine solution to the problem is needed.... in the way directory entries are laid out (see below). The version of the file system with this extension is usually known as VFAT after the Windows 95 VxD
VxD
VxD is the device driver model used in Windows 2.1x, the 386 enhanced mode of Windows 3.1x and Windows 9x. They have access to the memory of the kernel and all running processes, as well as raw access to the hardware.... device driver, also known as "Virtual FAT" in Microsoft's documentation.
Interestingly, the VFAT driver actually appeared before Windows 95, in Windows for Workgroups 3.11, but was only used for implementing 32-bit File Access
32-bit File Access
32-bit file access refers to the higher performance, protected mode disk caching method introduced in Windows for Workgroups 3.11, which replaced SmartDrive .... , a higher performance protected mode
Protected mode
In computing, protected mode, also called protected virtual address mode, is an operational mode of x86-compatible central processing units .... file access method, bypassing DOS and directly using either the BIOS
BIOS
In computing, the Basic Input/Output System , also known as the System BIOS, is a de facto standard defining a firmware interface for IBM PC Compatible computers.... , or, better, the Windows-native protected mode disk drivers.
In Windows NT, support for long filenames on FAT started from version 3.5
Windows NT 3.5
Windows NT 3.5 is the second release of the Microsoft Windows NT operating system. It was released on September 21 1994.One of the primary goals during Windows NT 3.5's development was to increase the speed of the operating system; as a result, the project was given the codename "Daytona" in reference to the Daytona International Speedway... . OS/2
OS/2
OS/2 is a computer operating system, initially created by Microsoft and IBM, then later developed by IBM exclusively. The name stands for "Operating System/2," because it was introduced as part of the same generation change release as IBM's "IBM Personal System/2 " line of second-generation personal computers.... added long filename support to FAT using extended attributes (EA) before the introduction of VFAT; thus, VFAT long filenames are invisible to OS/2, and EA long filenames are invisible to Windows.
FAT32
In order to overcome the volume size limit of FAT16, while still allowing DOS real mode
Real mode
Real mode, also called real address mode, is an operating mode of 80286 and later x86-compatible Central processing unit. Real mode is characterized by a 20 bit segmented memory address space , direct software access to BIOS routines and peripheral hardware, and no concept of memory protection or computer multitasking at the hardware le... code to handle the format without unnecessarily reducing the available conventional memory
Conventional memory
In computing, conventional memory is the first 640 kilobytes of the memory on IBM PC compatible systems.... , Microsoft implemented a newer generation of FAT, known as FAT32, with cluster values held in a 32-bit field, of which 28 bits are used to hold the cluster number, for a maximum of approximately 268 million (228) clusters. This allows for drive sizes of up to 8 tebibyte
Tebibyte
A tebibyte is a unit of information or computer storage, abbreviated TiB.The tebibyte is closely related to the terabyte, which can be either a synonym for tebibyte, or refer to 1012 bytes = 1,000,000,000,000 bytes, depending on context .... s with 32KB clusters, but the boot sector uses a 32-bit field for the sector count, limiting volume size to 2 TiB on a hard disk with 512 byte sectors.
On Windows 95/98, due to the version of Microsoft's SCANDISK
SCANDISK
SCANDISK or ScanDisk is a utility in MS-DOS and Microsoft Windows systems which checks and repairs file systems and bad Cluster s on the hard drive.... utility included with these operating systems being a 16-bit application, the FAT structure is not allowed to grow beyond around 4.2 million (< 222) clusters, placing the volume limit at 127.53 GiB
Gibibyte
Gibibyte is a unit of Computer data storage, abbreviated GiB.The gibibyte is closely related to the gigabyte, which can either be a synonym for gibibyte, or refer to 109 bytes = 1,000,000,000 bytes, depending on context .... . A limitation in original versions of Windows 98/98SE's Fdisk utility causes it to incorrectly report disk sizes over 64 GiB. A corrected version is available from Microsoft, but it cannot partition drives larger than 512GiB . These limitations do not apply to Windows 2000/XP except during Setup, in which there is a 32 GiB limit. Windows Me supports the FAT32 file system without any limits. However, similarly to Windows 95/98/98SE there is no native support for 48-bit LBA in Windows ME, meaning that the maximum disk size for ATA disks is 127.6 GiB, the maximum size of an ATA disk using the previous long-standard 28-bit LBA.
FAT32 was introduced with Windows 95 OSR2, although reformatting was needed to use it, and DriveSpace 3
DoubleSpace
DoubleSpace is a disk compression utility supplied with MS-DOS starting from version 6.0. The purpose of DoubleSpace was to increase the amount of data the user could store on disks, by transparently compressing and decompressing data on-the-fly.... (the version that came with Windows 95 OSR2 and Windows 98) never supported it. Windows 98 introduced a utility to convert existing hard disks from FAT16 to FAT32 without loss of data. In the NT line, native support for FAT32 arrived in Windows 2000
Windows 2000
Windows 2000 is a line of operating systems produced by Microsoft for use on business desktops, Laptop, and Server . Released on 17 February, 2000, it was the successor to Windows NT 4.0, and is the final release of Microsoft Windows to display the "Windows NT" designation.... . A free FAT32 driver for Windows NT 4.0
Windows NT 4.0
Windows NT 4.0 is a Preemption , Graphical user interface and business-oriented operating system designed to work with either uniprocessor or Symmetric multiprocessing computers.... was available from Winternals, a company later acquired by Microsoft. Since the acquisition the driver is no longer officially available.
Windows XP is a line of operating systems produced by Microsoft for use on personal computers, including home and business desktops, laptop, and media centers.... can read and write to FAT32 file systems of any size, but the format program included in Windows 2000 and higher can only create FAT32 file systems of 32 GiB or less. This limitation is by design and according to Microsoft was imposed because many tasks on a very large FAT32 file system become slow and inefficient. This limitation can be bypassed by using third-party formatting utilities or by using the built-in FORMAT.EXE command-line utility.
The maximum possible size for a file on a FAT32 volume is 4 GiB minus 1 byte (232−1 bytes). Video applications, large databases, and some other software easily exceed this limit. Larger files require another formatting type such as NTFS
NTFS
NTFS is the standard file system of Windows NT, including its later versions Windows 2000, Windows XP, Windows Server 2003, Windows Server 2008, Windows Vista, and Windows 7.... . Until mid-2006, those who run dual boot
Dual boot
Multi boot or Multi booting is the act of installing multiple operating systems on a computer, and being able to choose which one to Booting when switching on the computer power.... systems or who move external data drives between computers with different operating systems had little choice but to stick with FAT32. Since then, full support for NTFS has become available in Linux and many other operating systems, by installing the FUSE library
Filesystem in Userspace
Filesystem in Userspace is a loadable kernel module for Unix-like computer operating systems, that allows non-privileged users to create their own file systems without editing the Kernel code.... (on Linux) together with the NTFS-3G
NTFS-3G
NTFS-3G is an open source cross-platform implementation of the Microsoft Windows NTFS file system with read-write support. NTFS-3G uses the Filesystem in Userspace file system interface, so it can run unmodified on many different operating systems.... driver. Data exchange is also possible between Windows and Linux by using the Linux-native ext2
Ext2
The ext2 or second extended filesystem is a file system for the Linux kernel . It was initially designed by R?my Card as a replacement for the extended file system .... or ext3
Ext3
The ext3 or third extended filesystem is a journaling file system that is commonly used by the Linux operating system. It is the default file system for many popular Linux distributions.... file systems through the use of external drivers for Windows, such as ext2 IFS; however, Windows cannot boot from ext2 or ext3 partitions.
Fragmentation
The FAT file system does not contain mechanisms which prevent newly written files from becoming scattered across the partition. Other file systems, like HPFS
HPFS
HPFS or High Performance File System is a file system created specifically for the OS/2 operating system to improve upon the limitations of the File Allocation Table file system.... , use free space bitmaps that indicate used and available clusters, which could then be quickly looked up in order to find free contiguous areas (improved in exFAT
ExFAT
exFAT is a proprietary format file system suited especially for flash drives, introduced by Microsoft for embedded devices in Windows Embedded CE 6.0 and in their desktop operating system, starting with Windows Vista#Service Pack 1.... ). Another solution is the linkage of all free clusters into one or more lists (as is done in Unix
Unix
Unix is a computer operating system originally developed in 1969 by a group of American Telephone & Telegraph employees at Bell Labs, including Ken Thompson , Dennis Ritchie, Douglas McIlroy, and Joe Ossanna.... file systems). Instead, the FAT has to be scanned as an array to find free clusters, which can lead to performance penalties with large disks.
In fact, computing free disk space on FAT is one of the most resource intensive operations, as it requires reading the entire FAT linearly. A possible justification suggested by Microsoft's Raymond Chen
Raymond Chen
Raymond Chen is a well-known developer on the Microsoft Windows Windows Shell team at Microsoft. Since joining Microsoft in 1992, Chen has worked on OS/2, Windows 95, DirectX, and later versions of Windows.... for limiting the maximum size of FAT32 partitions created on Windows was the time required to perform a "DIR" operation, which always displays the free disk space as the last line. Displaying this line took longer and longer as the number of clusters increased.
The High Performance File System (HPFS) divides disk space into bands, which have their own free space bitmap, where multiple files opened for simultaneous write could be expanded separately.
In computer storage, fragmentation is a phenomenon in which storage space is used inefficiently, reducing storage capacity. The term is also used to denote the wasted space itself.... resulted from operating system and hardware limitations.
Native Command Queuing is a technology designed to increase performance of SATA hard disks under certain situations by allowing the individual hard disk to internally optimize the order in which received read and write commands are executed.... , no DMA transfers
Programmed input/output
Programmed input/output is a method of transferring data between the Central processing unit and a peripheral such as a network adapter or an AT Attachment storage device.... ) did not contain mechanisms which could alleviate fragmentation by asynchronously prefetching next data while the application was processing the previous chunks.
Similarly, write-behind caching was often not enabled by default with Microsoft software (if present) given the problem of data loss in case of a crash, made easier by the lack of hardware protection between applications and the system.
MS-DOS also did not offer a system call which would allow applications to make sure a particular file has been completely written to disk in the presence of deferred writes (cf. fsync
Sync (Unix)
sync is a standard system call in the Unix operating system, which commits to disk all data in the kernel filesystem buffer , i.e. data which has been scheduled for writing via low-level I/O system calls.... in Unix or DosBufReset in OS/2
OS/2
OS/2 is a computer operating system, initially created by Microsoft and IBM, then later developed by IBM exclusively. The name stands for "Operating System/2," because it was introduced as part of the same generation change release as IBM's "IBM Personal System/2 " line of second-generation personal computers.... ). Disk caches on MS-DOS were operating on disk block level and were not aware of higher-level structures of the file system. In this situation, cheating with regard to the real progress of a disk operation was most dangerous.
Modern operating systems have introduced these optimizations to FAT partitions, but optimizations can still produce unwanted artifacts in case of a system crash. A Windows NT system will allocate space to files on FAT in advance, selecting large contiguous areas, but in case of a crash, files which were being appended will appear larger than they were ever written into, with dozens of random kilobytes at the end.
With the large cluster sizes, 16 or 32K, forced by larger FAT32 partitions, the external fragmentation becomes somewhat less significant, and internal fragmentation, ie. disk space waste (since files are rarely exact multiples of cluster size), starts to be a problem as well, especially when there are a great many small files.
Linux is a generic term referring to Unix-like computer operating systems based on the Linux kernel. Their development is one of the most prominent examples of free and open source software collaboration; typically all the underlying source code can be used, freely modified, and redistributed by anyone under the terms of the GNU GPL license... , FreeBSD
FreeBSD
FreeBSD is a Unix-like free software operating system descended from AT&T Unix via the Berkeley Software Distribution branch through the 386BSD and Berkeley Software Distribution#4.4BSD and descendants operating systems.... , BeOS
BeOS
BeOS was an operating system for personal computers which began development by Be Inc. in 1991. It was first written to run on BeBox hardware. BeOS was optimized for digital media work and was written to take advantage of modern hardware facilities such as symmetric multiprocessing by utilizing modular I/O bandwidth, pervasive multithreading,... and JNode
JNode
JNode is an open-source project to create a Java platform operating system. The project has taken the unique direction of creating all the software in Java itself, with the exception of some assembly language to booting and load the system.... —have all supported FAT, and most added support for VFAT, FAT32, shortly after the corresponding Windows versions were released. Early Linux distributions also supported a format known as UMSDOS
UMSDOS
UMSDOS is an overlay filesystem driver for Linux that provides traditional Unix filesystem semantics in a File Allocation Table volume, such as those used by DOS, MS-DOS or Microsoft Windows for floppy disk.... , which was FAT with Unix file attributes (such as long file name and access permissions) stored in a separate file called “--linux-.---”. UMSDOS fell into disuse after VFAT was released and is not enabled by default in Linux kernel
Linux kernel
The Linux kernel is an operating system kernel used by a family of Unix-like operating systems. The term Linux distribution is used to refer to the various operating systems that run on top of the Linux Kernel.... s from version 2.5.7 onwards. The Mac OS X
Mac OS X
Mac OS X is a line of computer operating systems developed, marketed, and sold by Apple Inc., and since 2002 has been included with all new Macintosh computer systems.... operating system also supports the FAT file systems on volumes other than the boot disk
Boot disk
A boot disk is a removable digital data storage medium from which a computer can load and run an operating system or utility program. The computer must have a built-in program which will load and execute a program from a boot disk meeting certain standards.... . The Amiga
Amiga
The Amiga is a family of personal computers originally developed by Amiga Corporation. Development on the Amiga began in 1982 with Jay Miner as the principal hardware designer.... supports FAT through the CrossDOS
CrossDOS
CrossDOS is file system for AmigaDOS. It was bundled with AmigaOS 2.1 and later, though it did work under Amiga OS 2.04. Its function was to allow working with floppy disks formatted for IBM PC compatible .... file system.
FAT and Alternate Data Streams
The FAT file system itself is not designed for supporting Alternate Data Streams (ADS
Fork (filesystem)
In computer file systems, a fork is additional data associated with a file system object. A file system might support only one fork per file or might support multiple named forks.... ), but some operating systems that heavily depend on them have devised various methods for handling them in FAT drives. Such methods either store the additional information in extra files and directories (Mac OS), or give new semantics to previously unused fields of the FAT on-disk data structures (OS/2 and Windows NT). The second design, while presumably more efficient, prevents any copying or backing-up of those volumes using non-aware tools; manipulating such volumes using non-aware disk utilities (e.g. defragmenters or CHKDSK
CHKDSK
CHKDSK is a command on computers running DOS, OS/2 and Microsoft Windows operating systems that displays the file system integrity status of hard disks and floppy disk and can fix logical file system errors.... ) will probably lose the information.
Mac OS is the trademarked name for a series of graphical user interface-based operating systems developed by Apple Inc. for their Macintosh line of computer systems.... using PC Exchange
PC Exchange
PC Exchange was a Mac OS control panel that lets the operating system mount File Allocation Table file systems and mapped filename extension to the user-defined type code and creator codes.... stores its various dates, file attributes and long filenames in a hidden file called FINDER.DAT, and resource fork
Resource fork
The resource fork is a construct of the Mac OS operating system used to store structured data in a file, alongside unstructured data stored within the data fork.... s (a common Mac OS ADS) in a subdirectory called RESOURCE.FRK, in every directory where they are used. From PC Exchange 2.1 onwards, they store the Mac OS long filenames as standard FAT long filenames and convert FAT filenames longer than 31 characters to unique 31-character filenames, which can then be made visible to Macintosh applications.
Mac OS X stores resource forks and metadata (file attributes, other ADS) in a hidden file with a name constructed from the owner filename prefixed with "._", and Finder stores some folder and file metadata in a hidden file called ".DS Store
.DS Store
.DS_Store is a Hidden file and hidden directory created by Apple Inc.'s Mac OS X operating system to store custom attributes of a directory such as the position of Icon or the choice of a background image.... ".
OS/2 is a computer operating system, initially created by Microsoft and IBM, then later developed by IBM exclusively. The name stands for "Operating System/2," because it was introduced as part of the same generation change release as IBM's "IBM Personal System/2 " line of second-generation personal computers.... heavily depends on extended attributes (EAs) and stores them in a hidden file called "EA DATA. SF" in the root directory of the FAT12 or FAT16 volume. This file is indexed by 2 previously reserved bytes in the file's (or directory's) directory entry. In the FAT32 format, these bytes hold the upper 16 bits of the starting cluster number of the file or directory, hence making it difficult to store EAs on FAT32. Extended attributes are accessible via the Workplace Shell
Workplace Shell
The Workplace Shell is an award-winning object-oriented desktop shell produced by IBM's Boca Raton development lab for OS/2 2.0 using GUI technology licensed from Commodore Amiga.... desktop, through REXX
REXX
REXX is an Interpreted language programming language which was developed at IBM. It is a structured high-level programming language which was designed to be both easy to learn and easy to read.... scripts, and many system GUI
Graphical user interface
A graphical user interface is a type of user interface which allows people to human-computer interaction such as computers; hand-held devices such as MP3 Players, Portable Media Players or Gaming devices; household appliances and office equipment.... and command-line
Command line interface
A command-line interface is a mechanism for interacting with a computer operating system or software by typing commands to perform specific tasks.... utilities (such as 4OS2
4DOS
4DOS is a command line interpreter by JP Software, designed to replace the default command interpreter COMMAND.COM in DOS and Windows 95/Windows 98/Windows Me.... ).
OS/2 is a computer operating system, initially created by Microsoft and IBM, then later developed by IBM exclusively. The name stands for "Operating System/2," because it was introduced as part of the same generation change release as IBM's "IBM Personal System/2 " line of second-generation personal computers.... subsystem, Windows NT
Windows NT
Windows NT is a family of operating systems produced by Microsoft, the first version of which was released in July 1993. It was originally designed to be a powerful high-level-language-based, processor-independent, multiprocessing, multiuser operating system with features comparable to Unix.... supports the handling of extended attributes in HPFS, NTFS
NTFS
NTFS is the standard file system of Windows NT, including its later versions Windows 2000, Windows XP, Windows Server 2003, Windows Server 2008, Windows Vista, and Windows 7.... , and FAT. It stores EAs on FAT and HPFS using exactly the same scheme as OS/2, but does not support any other kind of ADS as held on NTFS volumes. Trying to copy a file with any ADS other than EAs from an NTFS volume to a FAT or HPFS volume gives a warning message with the names of the ADSs that will be lost.
Windows 2000 onward acts exactly as Windows NT, except that it ignores EAs when copying to FAT32 without any warning (but shows the warning for other ADSs, like "Macintosh Finder Info" and "Macintosh Resource Fork").
Future
Microsoft has recently secured patents for VFAT and FAT32 (but not the original FAT). Despite two earlier rulings against them, Microsoft prevailed and was awarded the patents.
NTFS is the standard file system of Windows NT, including its later versions Windows 2000, Windows XP, Windows Server 2003, Windows Server 2008, Windows Vista, and Windows 7.... file system is superior to FAT in terms of features and reliability; its main drawbacks are the size overhead for small volumes and the very limited support by anything other than the NT-based versions of Windows, since the exact specification is a trade secret
Trade secret
A trade secret is a formula, Best practice, process, design, Legal instrument, pattern, or compilation of information which is not generally known or reasonably ascertainable, by which a business can obtain an economic advantage over competitors or customers.... of Microsoft. The availability of NTFS-3G
NTFS-3G
NTFS-3G is an open source cross-platform implementation of the Microsoft Windows NTFS file system with read-write support. NTFS-3G uses the Filesystem in Userspace file system interface, so it can run unmodified on many different operating systems.... since mid 2006 has led to much improved NTFS support in Unix-like
Unix-like
A Unix-like operating system is one that behaves in a manner similar to a Unix system, while not necessarily conforming to or being certified to any version of the Single UNIX Specification.... operating systems, considerably alleviating this concern. It is still not possible to use NTFS in DOS-like operating systems without third-party drivers, which in turn makes it difficult to use a DOS floppy for recovery purposes. Microsoft provided a recovery console
Recovery Console
The Recovery Console is a feature of the Windows 2000, Windows XP and Windows Server 2003 operating systems. It provides the means for administrators to perform a limited range of tasks using a command line interface.... to work around this issue, but for security reasons it severely limited what could be done through the Recovery Console by default. The movement of recovery utilities to boot CDs based on BartPE
BartPE
BartPE is a lightweight variant of Microsoft Windows XP or Windows Server 2003 32bit operating systems, similar to a Windows Preinstallation Environment, which can be run from a Live CD or Live USB drive.... or Linux (with NTFS-3G) is finally eroding this drawback.
FAT is still the normal file system for removable media (with the exception of CDs and DVDs), with FAT12 used on floppies, and FAT16 or FAT32 on most other removable media (such as flash memory
Flash memory
Flash memory is a non-volatile memory computer storage that can be electrically erased and reprogrammed. It is a technology that is primarily used in memory cards and USB flash drives for general storage and transfer of data between computers and other digital products.... cards for digital camera
Digital camera
A digital camera is a camera that takes video or still photographs, or both, digitally by recording digital image via an electronics .Many compact digital still cameras can record sound and moving video as well as still photographs.... s and USB flash drives). Some removable media are not yet large enough to benefit from FAT32 and FAT16 is used on these drives for reasons of compatibility and size overhead, although some larger flash drives, like SDHC, do make use of it.
The FAT32 formatting support in Windows 2000 and XP is limited to volumes of 32 GB, which effectively forces users of modern hard drives either to use NTFS
NTFS
NTFS is the standard file system of Windows NT, including its later versions Windows 2000, Windows XP, Windows Server 2003, Windows Server 2008, Windows Vista, and Windows 7.... , to partition the drive into smaller volumes (below 32 GB), or to format the drive using third party tools.
exFAT
exFAT is an incompatible replacement for FAT file systems that was introduced with Windows Embedded CE 6.0. It is intended to be used on flash drives
USB flash drive
A USB flash drive consists of a Flash memory#NAND memories-type flash memory data storage device integrated with a USB interface. USB flash drives are typically removable and rewritable, much smaller than a floppy disk , and most USB flash drives weigh less than an ounce .... , where FAT is used today. Now Windows XP file system drivers are offered by Microsoft at
http://www.microsoft.com/downloads/details.aspx?FamilyID=1cbe3906-ddd1-4ca2-b727-c2dff5e30f61&displaylang=en
, while Windows Vista Service Pack 1 added exFAT support to Windows Vista. exFAT introduces a free space bitmap allowing faster space allocation and faster deletes, support for files up to 264 bytes, larger cluster sizes (up to 32 MB in the first implementation), an extensible directory structure and name hashes for filenames for faster comparisons. It does not have short 8.3 filenames anymore. It does not appear to have security access control list
Access control list
With respect to a computer filesystem, an access control list is a list of permissions attached to an object. The list specifies who or what is allowed to access the object and what operations are allowed to be performed on the object.... s or file system journaling
Journaling file system
A journalingfile system is a file system that logs changes to a journal before committing them to the main file system. Such file systems are less likely to become corrupted in the event of power failure or system crash.... like NTFS
NTFS
NTFS is the standard file system of Windows NT, including its later versions Windows 2000, Windows XP, Windows Server 2003, Windows Server 2008, Windows Vista, and Windows 7.... , though device manufacturers can choose to implement simplified support for transactions (backup file allocation table used for the write operations, primary FAT for storing last known good allocation table).
Design
The following is an overview of the order of structures in a FAT partition or disk:
Boot Sector
FS Information Sector (FAT32 only)
More reserved sectors (optional)
File Allocation Table #1
File Allocation Table #2
Root Directory (FAT12/16 only)
Data Region (for files and directories) ... (To end of partition or disk)
A FAT file system is composed of four different sections.
The Reserved sectors, located at the very beginning. The first reserved sector (sector 0) is the Boot Sector
Boot sector
A boot sector is a disk_sector of a hard disk, floppy disk, or similar data storage device that contains code for booting computer programs stored in other parts of the disk.... (aka Partition Boot Record). It includes an area called the BIOS Parameter Block
BIOS parameter block
In computing, the BIOS parameter block, often shortened to BPB, is a data structure describing the physical layout of a Computer data storage Volume .... (with some basic file system information, in particular its type, and pointers to the location of the other sections) and usually contains the operating system's boot loader code. The total count of reserved sectors is indicated by a field inside the Boot Sector. Important information from the Boot Sector is accessible through an operating system structure called the Drive Parameter Block in DOS and OS/2. For FAT32 file systems, the reserved sectors include a File System Information Sector at sector 1 and a Backup Boot Sector at Sector 6.
The FAT Region. This typically contains two copies (may vary) of the File Allocation Table for the sake of redundancy checking, although the extra copy is rarely used, even by disk repair utilities. These are maps of the Data Region, indicating which clusters are used by files and directories.
The Root Directory Region. This is a Directory Table that stores information about the files and directories located in the root directory. It is only used with FAT12 and FAT16 and means that the root directory has a fixed maximum size which is pre-allocated at creation of this volume. FAT32 stores the root directory in the Data Region along with files and other directories instead, allowing it to grow without such a constraint.
The Data Region. This is where the actual file and directory data is stored and takes up most of the partition. The size of files and subdirectories can be increased arbitrarily (as long as there are free clusters) by simply adding more links to the file's chain in the FAT. Note however, that files are allocated in units of clusters, so if a 1 KiB file resides in a 32 KiB cluster, 31 KiB are wasted.
In computing, endianness is the byte ordering used to represent some kind of data. Typical cases are the order in which integer values are stored as bytes in computer memory and the transmission order over a network or other medium.... format for entries in the header and the FAT(s).
Boot Sector
Common structure of the first 36 bytes used by all FAT versions:
Byte Offset
Length (bytes)
Description
0x00
3
Jump instruction. This instruction will be executed and will skip past the rest of the (non-executable) header if the partition is booted from. See Volume Boot Record
Volume Boot Record
A Volume Boot Record is a type of boot sector, stored in a volume on a hard disk, floppy disk, or similar data storage device, that contains code for booting computer programs stored in other parts of the volume.... . If the jump is two-byte near jmp it is followed by a NOP instruction.
0x03
8
OEM Name (padded with spaces). MS-DOS checks this field to determine which other parts of the boot record can be relied on. Common values are IBM 3.3 (with two spaces between the "IBM" and the "3.3"), MSDOS5.0 and MSWIN4.1.
0x0b
2
Bytes per sector. A common value is 512, especially for file systems on IDE (or compatible) disks. The BIOS Parameter Block starts here.
0x0d
1
Sectors per cluster. Allowed values are powers of two from 1 to 128. However, the value must not be such that the number of bytes per cluster becomes greater than 32 KB
Kilobyte
Kilobyte is a unit of Computer data storage equal to either 1,024 bytes or 1,000 bytes , depending on context.It is abbreviated in a number of ways: KB, kB, K and Kbyte.... .
0x0e
2
Reserved sector count. The number of sectors before the first FAT in the file system image. Should be 1 for FAT12/FAT16. Usually 32 for FAT32.
0x10
1
Number of file allocation tables. Almost always 2.
0x11
2
Maximum number of root directory entries. Only used on FAT12 and FAT16, where the root directory is handled specially. Should be 0 for FAT32. This value should always be such that the root directory ends on a sector boundary (i.e. such that its size becomes a multiple of the sector size). 224 is typical for floppy disks.
0x13
2
Total sectors (if zero, use 4 byte value at offset 0x20)
0x15
1
Media descriptor
0xF0
3.5" Double Sided, 80 tracks per side, 18 or 36 sectors per track (1.44MB or 2.88MB). 5.25" Double Sided, 15 sectors per track (1.2MB). Used also for other media types.
0xF8
Fixed disk (i.e. Hard disk).
0xF9
3.5" Double sided, 80 tracks per side, 9 sectors per track (720K). 5.25" Double sided, 40 tracks per side, 15 sectors per track (1.2MB)
0xFA
5.25" Single sided, 80 tracks per side, 8 sectors per track (320K)
0xFB
3.5" Double sided, 80 tracks per side, 8 sectors per track (640K)
0xFC
5.25" Single sided, 40 tracks per side, 9 sectors per track (180K)
0xFD
5.25" Double sided, 40 tracks per side, 9 sectors per track (360K). Also used for 8".
0xFE
5.25" Single sided, 40 tracks per side, 8 sectors per track (160K). Also used for 8".
0xFF
5.25" Double sided, 40 tracks per side, 8 sectors per track (320K)
0x16
2
Sectors per File Allocation Table for FAT12/FAT16
0x18
2
Sectors per track
0x1a
2
Number of heads
0x1c
4
Hidden sectors
0x20
4
Total sectors (if greater than 65535; otherwise, see offset 0x13)
Further structure used by FAT12 and FAT16, also known as Extended BIOS Parameter Block:
Byte Offset
Length (bytes)
Description
0x24
1
Physical drive number
0x25
1
Reserved ("current head")
In Windows NT
bit 0 is a dirty flag to request chkdsk at boot time.
bit 1 requests surface scan too.
0x26
1
Extended boot signature. Value is 0x29 or 0x28.
0x27
4
ID (serial number)
0x2b
11
Volume Label, padded with blanks (0x20).
0x36
8
FAT file system type, padded with blanks (0x20), e.g.: "FAT12 ", "FAT16 ". This is not meant to be used to determine drive type, however, some utilities use it in this way.
0x3e
448
Operating system boot code
0x1FE
2
Boot sector signature (0x55 0xAA)
The boot sector is portrayed here as found on e.g. an OS/2 1.3 boot diskette. Earlier versions used a shorter BIOS Parameter Block and their boot code would start earlier (for example at offset 0x2b in OS/2 1.1).
MS-DOS is an operating system commercialized by Microsoft. It was the most commonly used member of the DOS family of operating systems and was the main operating system for personal computers during the 1980s.... for the Apricot PC
Apricot PC
The Apricot PC was Apricot Computers' first personal computer made for business use. It had two 3.5" floppy drives and a keyboard with an LCD screen.... had a different boot sector layout, to accommodate that computer's non-IBM compatible BIOS. The jump instruction and OEM name were omitted, and the MS-DOS file system parameters (offsets 0x0B - 0x17 in the standard sector) were located at offset 0x50. Later versions of Apricot MS-DOS gained the ability to read and write disks with the standard boot sector in addition to those with the Apricot one.
DOS Plus is an operating system written by Digital Research, first released in 1985. It can be seen as an intermediate step between CP/M-86 and DR-DOS.... on the BBC Master
BBC Master
The BBC Master was a home computer released by Acorn Computers Ltd in early 1986. It was designed and built for the British Broadcasting Corporation and was the successor to the BBC Micro.... 512 did not use conventional boot sectors at all. Data disks omitted the boot sector and began with a single copy of the FAT (the first byte of the FAT was used to determine disk capacity) while boot disks began with a miniature ADFS
Advanced Disc Filing System
The Advanced Disc Filing System is a computing file system particular to the Acorn Computers Ltd computer range and RISC OS based successors.... file system containing the boot loader, followed by a single FAT. It could also access standard PC disks formatted to 180 KB or 360 KB, again using the first byte of the FAT to determine capacity.
FS Information Sector
The "FS Information Sector" was introduced in FAT32 for speeding up access times of certain operations (in particular, getting the amount of free space). It is located at a sector number specified in the boot record at position 0x30 (usually sector 1, immediately after the boot record).
Byte Offset
Length (bytes)
Description
0x00
4
FS information sector signature (0x52 0x52 0x61 0x41 / "RRaA")
0x04
480
Reserved (byte values are 0x00)
0x1e4
4
FS information sector signature (0x72 0x72 0x41 0x61 / "rrAa")
0x1e8
4
Number of free clusters on the drive, or -1 if unknown
0x1ec
4
Number of the most recently allocated cluster
0x1f0
14
Reserved (byte values are 0x00)
0x1fe
2
FS information sector signature (0x55 0xAA)
File Allocation Table
A partition is divided up into identically sized clusters, small blocks of contiguous space. Cluster sizes vary depending on the type of FAT file system being used and the size of the partition, typically cluster sizes lie somewhere between 2 KB and 32 KB. Each file may occupy one or more of these clusters depending on its size; thus, a file is represented by a chain of these clusters (referred to as a singly linked list
Linked list
In computer science, a linked list is one of the fundamental data structures, and can be used to implement other data structures. It consists of a sequence of node s, each containing arbitrary data Field s and one or two reference s pointing to the next and/or previous nodes.... ). However these clusters are not necessarily stored adjacent to one another on the disk's surface but are often instead fragmented throughout the Data Region.
The File Allocation Table (FAT) is a list of entries that map to each cluster on the partition. Each entry records one of five things:
the cluster number of the next cluster in a chain
a special end of clusterchain (EOC) entry that indicates the end of a chain
a special entry to mark a bad cluster
a special entry to mark a reserved cluster
a zero to note that the cluster is unused
Each version of the FAT file system uses a different size for FAT entries. Smaller numbers result in a smaller FAT table, but waste space in large partitions by needing to allocate in large clusters. The FAT12 file system uses 12 bits per FAT entry, thus two entries span 3 bytes. It is consistently little-endian: if you consider the 3 bytes as one little-endian 24-bit number, the 12 lsbits are the first entry and the 12 msbits are the second.
In the FAT32 file system, FAT entries are 32 bits, but only 28 of these are actually used; the 4 msbits are reserved.
FAT entry values:
FAT12
FAT16
FAT32
Description
0x000
0x0000
0x00000000
Free Cluster
0x001
0x0001
0x00000001
Reserved value; do not use
0x002–0xFEF
0x0002–0xFFEF
0x00000002–0x0FFFFFEF
Used cluster; value points to next cluster
0xFF0–0xFF6
0xFFF0–0xFFF6
0x0FFFFFF0–0x0FFFFFF6
Reserved values; do not use.
0xFF7
0xFFF7
0x0FFFFFF7
Bad sector in cluster or reserved cluster
0xFF8–0xFFF
0xFFF8–0xFFFF
0x0FFFFFF8–0x0FFFFFFF
Last cluster in file
Note that FAT32 uses only 28 bits of the 32 possible bits. The upper 4 bits are usually zero (as indicated in the table above) but are reserved and should be left untouched.
The first cluster of the Data Region is cluster #2. That leaves the first two entries of the FAT unused. In the first byte of the first entry a copy of the media descriptor is stored. The remaining 8 bits (if FAT16), or 20 bits (if FAT32) of this entry are 1. In the second entry the end-of-cluster-chain marker is stored. The high order two bits of the second entry are sometimes, in the case of FAT16 and FAT32, used for dirty volume management: high order bit 1: last shutdown was clean; next highest bit 1: during the previous mount no disk I/O errors were detected.
Directory table
A directory table is a special type of file that represents a directory (also known as a folder). Each file or directory stored within it is represented by a 32-byte entry in the table. Each entry records the name, extension, attributes (archive
Archive bit
The archive bit is a binary bit. As such, it is either 1 or 0, also frequently called set and clear or reset . It represents whether the file has or has not changed since the last backup.... , directory, hidden, read-only, system and volume), the date and time of creation, the address of the first cluster of the file/directory's data and finally the size of the file/directory.
Aside from the Root Directory Table in FAT12 and FAT16 file systems, which occupies the special Root Directory Region location, all Directory Tables are stored in the Data Region. The actual number of entries in a directory stored in the Data Region can grow by adding another cluster to the chain in the FAT.
Legal characters for DOS file names include the following:
Upper case letters A–Z
Numbers 0–9
Space (though trailing spaces in either the base name or the extension are considered to be padding and not a part of the file name, also filenames with space in them could not be used on the DOS command line prior to Windows 95 because of the lack of a suitable escaping system)
American Standard Code for Information Interchange , is a coding standard that can be used for interchanging information, if the information is expressed mainly by the written form of English words.... characters:
In computing and telecommunication, an escape character is a single character which in a sequence of characters signifies that what is to follow takes an alternative interpretation....
+ , . ; = [ ] They are allowed in long file names only.
Lower case letters a–z Stored as A–Z. Allowed in long file names.
Code page is the traditional International Business Machines term used to map a specific set of characters to numerical code point values . This is slightly different in meaning than the related terms character encoding and character set.... .
Directory entries, both in the Root Directory Region and in subdirectories, are of the following format (see also 8.3 filename):
Byte Offset
Length
Description
0x00
8
DOS file name (padded with spaces)
The first byte can have the following special values:
0x00
Entry is available and no subsequent entry is in use
0x05
Initial character is actually 0xE5
0x2E
'Dot' entry; either '.' or '..'
0xE5
Entry has been previously erased and is available. File undelete utilities must replace this character with a regular character as part of the undeletion process.
The archive bit is a binary bit. As such, it is either 1 or 0, also frequently called set and clear or reset . It represents whether the file has or has not changed since the last backup....
6
0x40
Device (internal use only, never found on disk)
7
0x80
Unused
0x0c
1
Reserved; two bits are used by NT and later versions to encode case information (see below); otherwise 0
0x0d
1
Create time, fine resolution: 10ms units, values from 0 to 199.
0x0e
2
Create time. The hour, minute and second are encoded according to the following bitmap:
Bits
Description
15-11
Hours (0-23)
10-5
Minutes (0-59)
4-0
Seconds/2 (0-29)
0x10
2
Create date. The year, month and day are encoded according to the following bitmap:
Bits
Description
15-9
Year (0 = 1980, 127 = 2107)
8-5
Month (1 = January, 12 = December)
4-0
Day (1 - 31)
0x12
2
Last access date; see offset 0x10 for description.
OS/2 is a computer operating system, initially created by Microsoft and IBM, then later developed by IBM exclusively. The name stands for "Operating System/2," because it was introduced as part of the same generation change release as IBM's "IBM Personal System/2 " line of second-generation personal computers.... and NT) in FAT12 and FAT16, High 2 bytes of first cluster number in FAT32
0x16
2
Last modified time; see offset 0x0e for description.
0x18
2
Last modified date; see offset 0x10 for description.
0x1a
2
First cluster in FAT12 and FAT16. Low 2 bytes of first cluster in FAT32. Entries with the Volume Label flag, subdirectory ".." pointing to root, and empty files with size 0 should have first cluster 0.
0x1c
4
File size in bytes. Entries with the Volume Label or Subdirectory flag set should have a size of 0.
Clusters are numbered from a cluster offset as defined above. That is, a zero in 0x1a would mean the first data segment is at:
Long file names
Long File Names (LFN) are stored on a FAT file system using a trick—adding (possibly multiple) additional entries into the directory before the normal file entry. The additional entries are marked with the Volume Label, System, Hidden, and Read Only attributes (yielding 0x0F), which is a combination that is not expected in the MS-DOS environment, and therefore ignored by MS-DOS programs and third-party utilities. Notably, a directory containing only volume labels is considered as empty and is allowed to be deleted; such a situation appears if files created with long names are deleted from plain DOS.
Older versions of PC-DOS mistake LFN names in the root directory for the volume label, and are likely to display an incorrect label.
Each phony entry can contain up to 13 UTF-16 characters (26 bytes) by using fields in the record which contain file size or time stamps (but not the starting cluster field, for compatibility with disk utilities, the starting cluster field is set to a value of 0. See 8.3 filename for additional explanations). Up to 20 of these 13-character entries may be chained, supporting a maximum length of 255 UTF-16 characters.
After the last UTF-16 character, a 0x00 0x00 is added. Other not used characters are filled with 0xFF 0xFF.
LFN entries use the following format:
Byte Offset
Length
Description
0x00
1
Sequence Number
0x01
10
Name characters (five UTF-16 characters)
0x0b
1
Attributes (always 0x0F)
0x0c
1
Reserved (always 0x00)
0x0d
1
Checksum of DOS file name
0x0e
12
Name characters (six UTF-16 characters)
0x1a
2
First cluster (always 0x0000)
0x1c
4
Name characters (two UTF-16 characters)
If there are multiple LFN entries, required to represent a file name, firstly comes the last LFN entry (the last part of the filename). The sequence number here also has bit 7 (0x40) checked (this means the last LFN entry. However it's the first entry got when reading the directory file). The last LFN entry has the biggest sequence number which decreases in following entries. The first LFN entry has sequence number 1. Bit 8 (0x80) of the sequence number is used to indicate that the entry is deleted.
For example if we have filename "File with very long filename.ext" it would be formatted like this:
A checksum or hash sum is a fixed-size data computed from an arbitrary block of digital data for the purpose of error detection that may have been introduced during its telecommunications or computer storage.... also allows verification of whether a long file name matches the 8.3 name; such a mismatch could occur if a file was deleted and re-created using DOS in the same directory position. The checksum is calculated using the algorithm below. (Note that pFcbName is a pointer to the name as it appears in a regular directory entry, i.e. the first eight characters are the filename, and the last three are the extension. The dot is implicit. Any unused space in the filename is padded with spaces (ASCII 0x20) char. For example, "Readme.txt" would be "README TXT".)
unsigned char lfn_checksum(const unsigned char *pFcbName)
If a filename contains only lowercase letters, or is a combination of a lowercase basename with an uppercase extension, or vice-versa; and has no special characters, and fits within the 8.3 limits, a VFAT entry is not created on Windows NT and later versions such as XP. Instead, two bits in byte 0x0c of the directory entry are used to indicate that the filename should be considered as entirely or partially lowercase. Specifically, bit 4 means lowercase extension and bit 3 lowercase basename, which allows for combinations such as "example.TXT" or "HELLO.txt" but not "Mixed.txt". Few other operating systems support this. This creates a backwards-compatibility problem with older Windows versions (95, 98, ME) that see all-uppercase filenames if this extension has been used, and therefore can change the name of a file when it is transported, such as on a USB flash drive. Current 2.6.x versions of Linux will recognize this extension when reading (source: kernel 2.6.18 /fs/fat/dir.c and fs/vfat/namei.c); the mount option shortname determines whether this feature is used when writing.
Third-party extensions
Before Microsoft added support for long filenames and creation/access time stamps, bytes 0x0C–0x15 of the directory entry were used by alternative operating systems to store additional metadata. These included:
RISC OS is a computer operating system which was originally developed by Acorn Computers Ltd in Cambridge, England for their ARM architecture based computers....
DOS Plus is an operating system written by Digital Research, first released in 1985. It can be seen as an intermediate step between CP/M-86 and DR-DOS....
MSX-DOS is a Disk operating system developed by Microsoft for the 8-bit home computer standard MSX, and is a cross between MS-DOS rev 1.0 and CP/M.... 2
For a deleted file, the original first character of the filename.
DR-DOS is a DOS-type operating system for IBM PC-PC compatible personal computers, originally developed by Gary Kildall's Digital Research and derived from CP/M-86....
For a deleted file, the original first character of the filename.
ANDOS is a Russian operating system for Electronika BK-0010, Electronika BK-0011 and Electronika BK-0011M series computers. It was created in 1990 and saw first release in 1992....
File address in the memory
0x10
4
DR-DOS 7
For a deleted file, its original file time and date; deleted files have their normal time and date fields set to the time of deletion
0x12
2
DR-DOS 6 and FlexOS
File owner ID
0x14
2
DR-DOS and FlexOS
File permissions bitmap (execute permissions are only used by FlexOS):
Bit
Mask
Description
0
0x0001
Owner delete requires password
1
0x0002
Owner execute requires password
2
0x0004
Owner write requires password
3
0x0008
Owner read requires password
4
0x0010
Group delete requires password
5
0x0020
Group execute requires password
6
0x0040
Group write requires password
7
0x0080
Group read requires password
8
0x0100
World delete requires password
9
0x0200
World execute requires password
10
0x0400
World write requires password
11
0x0800
World read requires password
FAT licensing
Microsoft applied for, and was granted, a series of patents for key parts of the FAT file system in the mid-1990s. Being almost universally compatible and well-understood, FAT is frequently chosen as an interchange format for flash media used in digital cameras and PDAs
Personal digital assistant
A personal digital assistant is a handheld computer, also known as a palmtop computer. Newer PDAs also have both color screens and audio capabilities, enabling them to be used as mobile phones, , web browsers, or portable media players.... .
On 2003-12-03 Microsoft announced it would be offering licenses for use of its FAT specification and "associated intellectual property", at the cost of a US$0.25 royalty per unit sold, with a $250,000 maximum royalty per license agreement.
To this end, Microsoft cited four patents on the FAT file system as the basis of its intellectual property claims. All four pertain to long-filename extensions to FAT first seen in Windows 95
Windows 95
Windows 95 is a consumer-oriented graphical user interface-based operating system. It was released on August 24, 1995 by Microsoft, and was a significant progression from the company's previous Microsoft Windows products.... :
Public Patent Foundation, or PUBPAT, is a nonprofit organization that seeks to limit perceived abuse of the United States patent law. It was founded in 2003 by Dan Ravicher.... successfully challenged this patent; the claims were rejected on 2004-09-14, due to prior disclosure of the claimed techniques in patents and . This decision was later overturned by the Patent Office on 2006-01-10.
The Public Patent Foundation successfully challenged this patent (USPTO); The USPTO rejected this patent on 2005-10-05, on the grounds that "the six assignees names were incorrect". This decision was also later overturned by the Patent Office on 2006-01-10.
Many technical commentators have concluded that these patents only cover FAT implementations that include support for long filenames, and that removable solid state media and consumer devices only using short names would be unaffected.
Additionally, in the document "Microsoft Extensible Firmware Initiative FAT 32 File System Specification, FAT: General Overview of On-Disk Format" published by Microsoft (version 1.03, 2000-12-06), Microsoft specifically grants a number of rights, which many readers have interpreted as permitting operating system vendors to implement FAT.
Microsoft is not the only company to have applied for patents for parts of the FAT file system. Other patents affecting FAT include:
Appeal
As there was widespread call for these patents to be re-examined, the Public Patent Foundation (PUBPAT) submitted evidence to the US Patent and Trade Office (USPTO) disputing the validity of these patents, including prior art references from Xerox
Xerox
Xerox Corporation is a global document management company which manufactures and sells a range of color and black-and-white Computer printer, multifunction systems, photo copiers, digital production printing presses, and related consulting services and supplies.... and IBM
IBM
International Business Machines Corporation, abbreviated IBM and nicknamed "Big Blue" , is a multinational corporation computer technology and consulting corporation headquartered in Armonk, New York, New York, United States.... . The USPTO acknowledged that the evidence raised "substantial new question[s] of patentability," and opened an investigation into the validity of Microsoft's FAT patents.
On 2004-09-30 the USPTO rejected all claims of , based primarily on evidence provided by PUBPAT. Dan Ravicher, the foundation's executive director, said, "The Patent Office has simply confirmed what we already knew for some time now, Microsoft's FAT patent is bogus."
According to the PUBPAT press release, "Microsoft still has the opportunity to respond to the Patent Office's rejection. Typically, third party requests for re-examination, like the one filed by PUBPAT, are successful in having the subject patent either narrowed or completely revoked roughly 70% of the time."
On 2005-10-05 the Patent Office announced that, following the re-examination process, it had again rejected all claims of patent 5,579,517, and it additionally found invalid on the grounds that the patent had incorrect assignees.
Finally, on 2006-01-10 the Patent Office ruled that features of Microsoft's implementation of the FAT system were "novel and non-obvious", reversing both earlier non-final decisions.
Microsoft Corporation is a multinational corporation computer technology corporation that develops, manufactures, licenses, and supports a wide range of computer software products for computing devices.... filed a patent infringement
Patent infringement
Patent infringement is the act of utilizing a patented invention without permission from the patent holder. Permission may typically be granted in the form of a licence.... lawsuit against TomTom
TomTom
TomTom NV is a Netherlands manufacturer of automotive navigation systems, including both stand-alone units and software for personal digital assistants, and mobile telephones.... alleging that the device maker's products infringe on patents related to FAT32 filesystem. As some TomTom products are based on Linux
Linux
Linux is a generic term referring to Unix-like computer operating systems based on the Linux kernel. Their development is one of the most prominent examples of free and open source software collaboration; typically all the underlying source code can be used, freely modified, and redistributed by anyone under the terms of the GNU GPL license... , this marked the first time that Microsoft tried to enforce its patents against the Linux platform..
Drive letter assignment is the process of assigning alphabetical identifiers to physical or logical disk drives or partition s in the root filesystem namespace; this usage is commonly found in Microsoft operating systems....
Software patent does not have a universally accepted definition. One definition suggested by the Foundation for a Free Information Infrastructure is that a software patent is a "patent on any performance of a computer realised by means of a computer program"....
The following lists identify, characterize and link to more thorough information on computer file systems.Many older operating systems support only their one "native" file system, which does not bear any name apart from the name of the operating system itself....
The 'Rock Ridge Interchange Protocol' is an extension to the ISO 9660 volume format which adds POSIX file system semantics. The standard takes its name from the fictional town in Mel Brooks' film Blazing Saddles.... and Joliet
Joliet (file system)
Joliet is the name of an extension to the ISO 9660 file system. It has been specified and endorsed by Microsoft and has been supported by all versions of its Microsoft Windows Operating system since Windows 95 and Windows NT.... — systems for CDs that add long file names similar to what VFAT did for FAT.
External links
, identical to ISO/IEC 9293.
including lots of info about LFNs
- Microsoft Knowledge Base Article 140418
- Microsoft Knowledge Base Article 154997
- Includes libfat libraries and fusefat , a FUSE filesystem driver
Raymond Chen is a well-known developer on the Microsoft Windows Windows Shell team at Microsoft. Since joining Microsoft in 1992, Chen has worked on OS/2, Windows 95, DirectX, and later versions of Windows....
: allows formatting volumes larger than 32GB with FAT32 under Windows 2000
Windows 2000
Windows 2000 is a line of operating systems produced by Microsoft for use on business desktops, Laptop, and Server . Released on 17 February, 2000, it was the successor to Windows NT 4.0, and is the final release of Microsoft Windows to display the "Windows NT" designation.... , Windows XP
Windows XP
Windows XP is a line of operating systems produced by Microsoft for use on personal computers, including home and business desktops, laptop, and media centers.... and Windows Vista
Windows Vista
Windows Vista is one member in a family of operating systems developed by Microsoft for use on personal computers, including home and business Desktop computer, laptops, Tablet PCs, and media center PCs....
- Microsoft Knowledge Base Article 263044.
- Copy made by of an article with summary of limits in FAT32 which is not longer available on Microsoft website.
, Open source FAT implementation for embedded devices
