file allocation table (English: File Allocation Table, acronym: FAT), also known as document distribution list, invented by Microsoft and is a part of the patent document has a system for MS-DOS to use, but also all non-NT Microsoft Windows kernel for use file system. FAT file system performance into account when the computer is limited, so is not complicated, so almost all personal computer operating systems are supported.
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interpretation of a historical interpretation of the second directory FAT16 FAT12 extended partition and logical beginning of the end of the FAT16 drive long file names (VFAT,
chi pink dazzle hair straightener, LFN) FAT32FAT16 and the FAT32 file system has a maximum capacity of third-party support for FAT partitions prospects, and other design data flow structure of the primary disk file allocation table table of third-party complaint granted patent extensions FAT FAT32 and NTFS notes into each other one. FAT32 NTFS turn two. NTFS turn a FAT32 FAT common problems dealing with the mechanical interpretation of the meaning of the manufacturing : Factory Acceptance Test, Factory Acceptance Test Interpretation second file allocation table (English: File Allocation Table, acronym: FAT) is a kind of invented by Microsoft, and fly off with part of the post-
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Lee [1] file system for MS-DOS to use, but also non-Microsoft Windows NT kernel file system used. FAT file system performance considering the computer was limited, so is not complicated, they have been almost all personal computer operating system support. This feature makes it an ideal disk and memory card file system, also suitable for different operating systems, data exchange. But the FAT has a serious drawback: When the file is deleted and the new data is written to the same location, and their fragments are usually scattered and slowed down to read and write speed. Disk fragmentation is re-engineering a solution, but it must always re-FAT file system to maintain efficiency. FAT also the shortcomings of the following: 1. Big waste of disk space 2. Disk utilization efficiency arrived 3. File storage restricted 4. Does not support long file names, can only support 8 characters. 5. Security is poor compliance history of FAT file system has been used for many years to regulate the software method. It in 1977 by Bill Gates and Thomas McDonald invented to manage the disks, and in 1980 by Tim Peterson's 86-DOS operating system used. This is the 86-DOS operating system CP / M operating system, the biggest difference, if not the difference ,86-DOS operating system CP / M operating system practically identical. FAT12 FAT is now commonly known as the beginning of the FAT12. As floppy disk file system, it has several limitations: no support for hierarchical structures, the cluster address only 12 bits (which makes control of FAT a bit tricky) and only supports up to 32M (216) of the partition. At that time entry-level disk is 5.25 Above exceeds the capacity limit of one or several orders of magnitude, while allowing all the control structures on the first track, so move the heads read and write operations. These restrictions in the next few years is to gradually increase. Because only the root directory must also be on the first track, the file can be stored on the limited number of dozens. Directory support for good with a 10MB hard drive featuring the new IBM PC XT computer, beginning in 1983, MS-DOS 2.0 is almost released at the same time with the computer, it introduced a hierarchical directory structure. In addition to allowing better organization of files, the directory allows the store more files on the hard disk, because the maximum number of files no longer subject to (still is fixed) root size. This number can now be equal to the number of clusters (or even more, which is given to the file length of 0 does not occupy any FAT clusters). FAT format itself has not changed. PC XT's 10MB of hard disk with 4KB cluster size. If you later install a 20MB hard drive, and formatted using the MS-DOS 2.0, the final cluster size becomes 8KB, hard disk capacity will become 15.9MB. FAT16 beginning in 1984, IBM released PC AT, which is a 20 MB hard drive. Microsoft also simultaneously released MS-DOS 3.0. Clustered address increased to 16 bits, allowing a larger number of clusters (maximum 65,517), so the size of a larger file system. However, the maximum number of sectors and the largest partition (the equivalent of the disk) size is still 32 MB. So, although technically already MS-DOS 3.0 format in a 20 MB hard disk, this disk will not be MS-DOS 2.0 or earlier versions of the access. Of course, MS-DOS 3.0 can still access the MS-DOS 2.0 format (8 KB cluster partition). MS-DOS 3.0 also began to support high-density 1.2MB 5.25 This may promote an uncertainty for the optimal cluster size, cluster size is reduced from two sectors 1. This final result is high-density disk than the old rate of double-density disk greatly reduced. Extended partitions and logical drives in addition to improving the structure of FAT file system itself, in addition, a parallel development of improved routes FAT storage space is to support multiple disk partitions. Initially, the primary boot partition file allocation table of a fixed structure, the reason can only use up to 4 hard disk partition. However, due to the design requirements can only have one DOS partition marked as DOS tool can not be used to create several In a compatible way to use more partitions, a new partition type was developed (1986] in January of the MS-DOS 3.2), it actually is another extended partition as a container for logical partitions. Initially it contains only one logical partition, supports a maximum 64MB of hard disk. In the MS-DOS 3.3 (1987 年 8 months) to change this limit to 24 partitions; it may come from the mandatory C:-Z: The disk naming conventions. Logical disk partition table data structure used to describe, might be to simplify the code it is very similar to the master boot record, and organize them into sets her way similar to the structure of Russia. The system can only have one extended partition. Before the introduction of the extended partition, some of the hard disk controller (then an independent board, because no IDE standard) the ability to display a large hard disk into two separate hard drives. As an alternative, such as Ontrack [1] of the disk administrator some special software that can be used for the same purpose. The final FAT16 1987 年 11 months we end today, the arrival of the format called FAT, which removed the Compaq DOS 3.31 disk sector in the 16-bit counter. This result was once known as the DOS 3.31 Large file system. Although the changes seem small on the disk, the DOS disk code must be checked and converted to 32 the number of sectors, as it all is 16-bit assembly language a reality, this becomes very complicated. This improvement in 1988 by MS-DOS 4.0 is widely used. Now each cluster partition size is limited to 8-bit signed count of sectors, it can reach the largest power of 2, 64, for a commonly used 32KB clusters of 512 bytes per sector for hard disk will be FAT16 partition size The In the magneto-optical media, it can use 1 or 2KB sectors, so that the size limit will increase proportionally. Later, Windows NT by the number of sectors of each cluster as unsigned increased the maximum cluster size of 64KB. However, this format to any other FAT implementation was not compatible and have a lot of internal fragmentation. Windows 98 also supports reading and writing in this format the disk management tool but it does not support this format. Long file names (VFAT, LFN) Windows 95, a user experience designer goal is in addition to the traditional 8.3 file name other than the new operating system in use long file names (LFN). Long file name entries in the directory arranged by the use of a work area to achieve (see below). Windows 95VxD device driver in accordance with the naming of this new expanded file system commonly referred to as VFAT. Interestingly, VFAT driver earlier than Windows 95, Windows for Groups 3.11 has appeared in, but it is only used to implement 32-bit file access, bypassing the DOS window comes with a high-performance document management system for protected mode, it can BIOS directly, or better 32-bit disk access, such as Windows native protected mode disk drivers. It is a back door; Microsoft Windows for Groups 3.11 for the advertisement by the 32-bit file access based on In Windows NT,, FAT file system, support for long file names from the 3.5 version has been started. To address the FAT16 FAT32 volume size limit for DOS real mode while allowing non-essential in the case does not reduce the conditions of conventional memory available to handle this format, Microsoft decided to implement a new generation of FAT, it is called FAT32, with 32 bit number of clusters on the current use of 28 of them. In theory,
chi iron, this would support a total of 268,435,438 ( ;> 1) + * pFcbName + +; return sum;} older version of PC-DOS error to the root directory of the long file name as a label, so that they will display the wrong label. Each entry contains 13UTF-off 16 characters (26 bytes), by using the include file size or time records obtained in addition to the area outside the old 8 +3 and 15 bytes (but for security and disk checking tools do not consider the start of regional clusters use the reserved value 0). See also the explanation in 8.3. If a filename contains only lowercase letters, lowercase letters or a name plus an extension of the mixed or upper case to the contrary, no special characters and meet the 8.3 restrictions on the Windows NT VFAT entry is not created. On the contrary, in the directory entry at offset 0x0c did not specify the file name bit is used to indicate all or part of the lowercase letters. especially clear is that, bit 4 means that the lower case extension letter, bit 3 means the name is lowercase, allowing as support this feature. non-NT version of Windows will use when the file name extension as a capital letter. By default, Linux will recognize the most recent version of this extension, but do not use it when writing. third-party extensions in the Microsoft the company added long file name and create / access timestamps before other operating systems table of bytes 0x0C-0x15 store other metadata. FAT patents Microsoft in the mid-twentieth century, applied for and obtained a series of core part of the FAT file system patent. Because of a wide range of compatibility and easy to understand, FAT is often chosen as used in digital cameras and personal digital assistants in the flash memory data exchange format. December 3, 2003 Microsoft announced the use of FAT specification and intellectual property claims as its foundation. all of these with the long file name extension on the FAT first appeared in Windows 95: U.S. Patent 5,745,902 - using a different file name format to access the file name of the method and system. July 6, 1992 for the record. This includes the generation, contact a 8.3-compatible short file name format and long file names methods (such as MICROS ~ 2.TXT FAT file delete a file name will also remove its short file name. will rename a file as a will re-generate a Search for the file name will appear when the two; they look instead of two separate files and they do not need to 24 record. This includes the 8.3 multiple consecutive directory entries are linked together to support long file names, some of which special items can be marked to prevent confusion in the early does not support long file names FAT implementation. Public Patent Foundation successfully challenged the patent; this patent application as the application of technology in the patent U.S. Patent 5,307,494 and U.S. Patent 5,367,671 in the early discovery in September 14, 2004 was rejected]. This decision was in January 2006 10, overthrown by the U.S. Patent Office. U.S. Patent 5,758,352 - long and short file names common namespace. September 5, 1996 for the record. It is very similar to 5,579,517. Public Patent Foundation successfully challenged the patent; United States Patent and Trademark Office on 6,286,013 - in the operating system for the long and short file names to provide a common method and system namespace. January 28, 1997 for the record. its application include Windows 95, Windows 98 and Windows Me provide long file names Leave them to MS-DOS compatibility layer method used. It does not appear to affect non-Microsoft FAT implementation. many of the technical comments assert these patents cover only the FAT support long file names to achieve, those who only use the short name of the mobile solid-state media and consumer equipment will not be affected. In addition, Microsoft December 6, 2000 issue of Many readers thought it allows the operating system vendor to achieve Microsoft's FAT. accused the widespread re-examination of these patents, Public Patent Foundation to the U.S. Patent and Trademark Office (USPTO) presented some evidence to dispute the validity of these patents, which including Xerox and IBM in the early references. United States Patent and Trademark Office acknowledged the evidence put forward United States Patent and Trademark Office Public Patent Foundation is based on the evidence provided by U.S. Patent 5,579,517 rejected the patent claims. The Dan Ravicher, executive director of the Foundation said, the company's patent is false. range or 70% chance of complete rejection of the patent. were invalid. Finally, in January 10, 2006, the Patent Office ruled that the realization of Microsoft's FAT system is characterized by file system technologies to support long file names, not file system kernel itself. ^ Duncan, Ray (1989). Design goals and implementation of the new High Performance File System. Microsoft Systems Journal 4 (5). ^ Thompson, Robert Bruce and Barbara Fritchman Thompson, PC Hardware in a Nutshell, 3rd Edition,, O'Reilly, ISBN 059600513X (p. 506 re Microsoft ^ Norton, Peter (2002 page file) FAT32 and NTFS into each other one. FAT32 switch to NTFS in the Start - Run, type CMD, then type convert X: / FS: NTFS (X: is the drive letter to the partition into) Restart transformed after the start. But such a transformation will have three drawbacks: 1. in fact not be a weakness, mainly converted to NTFS,
chi pink dazzle limited edition, the system default Everyone user on all directories, files that have full privileges, in fact, had to acquiesce to all users FAT32 Access! For security reasons, you need to reset the security features. on some important documents, should be eliminated everyone full permissions to the user. 2. transformed the NTFS partition, the first may be prone to disk fragmentation. 3.C the conversion to NTFS disk partition, be sure to pay attention to is not multi-system, there is not installed WIN9X, ME, which do not recognize NTFS partition system, if installed, then the C drive do not be converted to NTFS partition,
CHI Pink Dazzle Flat Iron, be sure to keep the original FAT partition. extended partition in addition to the logical partition is a partition installed WIN9X/ME system, other partitions can be converted to NTFS partitions. II. NTFS FAT32 turn now, more common method is to use PQ Magic to conversion (also available Acronis company Partation Expert, English, but full support for Chinese), but we must note that if a Chinese directory, file, Winrar must be packaged together with the English name of the archive, otherwise the Chinese directories, files will be inaccessible!! ! Frequently Asked Questions for 1. half-way off, the partition into PQRP type, can not be accessed, how do? can use the PQ installation directory PTEDIT32.exe ( PowerQuest PartitionMagic 8.0) to repair, just will mark the partition as PQRP (type 3C),
cheap chi straighteners, into FAT32/NTFS (type 07/0B) can be. If the C drive error,
chi turbo flat iron, can be loaded with real-mode DOS DOS version of the PTEDIT.exe ( PowerQuest PartitionMagic 8.0 DOS) to repair. Note: Other operating power PQ problems can be caused by processing according to the law, but also relative to the Diskgenius, PTEDIT32.exe can support NTFS partitions. 2. into partition, the Chinese can not access the directory, how do? can use GHOST partition cloning , and then use ghost Explorer to open gho backup file, rename the Chinese directory. [1] entry for more Atlas Atlas References 1
VISTA transferred under the FAT32 NTFS Detailed
http: / / article.wxiu.com/system/vista/200904/16-5507.html
Further reading: 1
http://www.fix.com.cn/data-recovery/post/fat_structure. htm FAT file system structure and the C-representation
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, FAT, NTFS I have to perfect the