computing Computing is any goal-oriented activity requiring, benefiting from, or creating computer, computing machinery. It includes the study and experimentation of algorithmic processes, and the development of both computer hardware, hardware and softw ...

, format is a

command-line A command-line interface (CLI) is a means of interacting with software via commands each formatted as a line of text. Command-line interfaces emerged in the mid-1960s, on computer terminals, as an interactive and more user-friendly alternativ ...

utility that carries out

disk formatting Disk formatting is the process of preparing a data storage device such as a hard disk drive, solid-state drive, floppy disk, memory card or USB flash drive for initial use. In some cases, the formatting operation may also create one or more new f ...

. It is a component of various

operating system An operating system (OS) is system software that manages computer hardware and software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for ...

s, including

86-DOS 86-DOS (known internally as QDOS, for Quick and Dirty Operating System) is a discontinued operating system developed and marketed by Seattle Computer Products (SCP) for its Intel 8086-based computer kit. 86-DOS shared a few of its commands wi ...

MS-DOS MS-DOS ( ; acronym for Microsoft Disk Operating System, also known as Microsoft DOS) is an operating system for x86-based personal computers mostly developed by Microsoft. Collectively, MS-DOS, its rebranding as IBM PC DOS, and a few op ...

IBM International Business Machines Corporation (using the trademark IBM), nicknamed Big Blue, is an American Multinational corporation, multinational technology company headquartered in Armonk, New York, and present in over 175 countries. It is ...

PC DOS PC or pc may refer to: Arts and entertainment * Player character or playable character, a fictional character controlled by a human player, usually in role-playing games or computer games * '' Port Charles'', an American daytime TV soap opera * ...

and

OS/2 OS/2 is a Proprietary software, proprietary computer operating system for x86 and PowerPC based personal computers. It was created and initially developed jointly by IBM and Microsoft, under the leadership of IBM software designer Ed Iacobucci, ...

Microsoft Microsoft Corporation is an American multinational corporation and technology company, technology conglomerate headquartered in Redmond, Washington. Founded in 1975, the company became influential in the History of personal computers#The ear ...

Windows Windows is a Product lining, product line of Proprietary software, proprietary graphical user interface, graphical operating systems developed and marketed by Microsoft. It is grouped into families and subfamilies that cater to particular sec ...

and

ReactOS ReactOS is a Free and open-source software, free and open-source operating system for i586/amd64 personal computers that is intended to be binary-code compatibility, binary-compatible with computer programs and device drivers developed for Wind ...

Overview

The

command Command may refer to: Computing * Command (computing), a statement in a computer language * command (Unix), a Unix command * COMMAND.COM, the default operating system shell and command-line interpreter for DOS * Command key, a modifier key on A ...

performs the following actions by default on a

floppy disk A floppy disk or floppy diskette (casually referred to as a floppy, a diskette, or a disk) is a type of disk storage composed of a thin and flexible disk of a magnetic storage medium in a square or nearly square plastic enclosure lined with a ...

hard disk drive A hard disk drive (HDD), hard disk, hard drive, or fixed disk is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating hard disk drive platter, pla ...

, solid state (

USB Universal Serial Bus (USB) is an industry standard, developed by USB Implementers Forum (USB-IF), for digital data transmission and power delivery between many types of electronics. It specifies the architecture, in particular the physical ...

), or other magnetic medium (it will not perform these actions on

optical media An optical disc is a flat, usuallyNon-circular optical discs exist for fashion purposes; see shaped compact disc. disc-shaped object that stores information in the form of physical variations on its surface that can be read with the aid o ...

): # clearing the

FAT In nutrition science, nutrition, biology, and chemistry, fat usually means any ester of fatty acids, or a mixture of such chemical compound, compounds, most commonly those that occur in living beings or in food. The term often refers specif ...

entries by changing them to # clearing the FAT root directory by changing any values found to (NB. While the publishers claim this would be MS-DOS 1.1 and 2.0, it actually is SCP MS-DOS 1.25 and a mixture of Altos MS-DOS 2.11 and TeleVideo PC DOS 2.11.) (NB. While the author claims this would be MS-DOS 1.1 and 2.0, it actually is SCP MS-DOS 1.25 and a mixture of Altos MS-DOS 2.11 and TeleVideo PC DOS 2.11.) (NB. While the author claims this would be MS-DOS 1.1 and 2.0, it actually is SCP MS-DOS 1.25 and a mixture of Altos MS-DOS 2.11 and TeleVideo PC DOS 2.11.) # checking each

cluster may refer to: Science and technology Astronomy * Cluster (spacecraft), constellation of four European Space Agency spacecraft * Cluster II (spacecraft), a European Space Agency mission to study the magnetosphere * Asteroid cluster, a small ...

to see if it is good or bad and marking it as good or bad in the FAT Any storage device must have its medium structured to be useful. This process is referred to as "creating a filesystem" in

Unix Unix (, ; trademarked as UNIX) is a family of multitasking, multi-user computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, a ...

Linux Linux ( ) is a family of open source Unix-like operating systems based on the Linux kernel, an kernel (operating system), operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically package manager, pac ...

, or

BSD The Berkeley Software Distribution (BSD), also known as Berkeley Unix or BSD Unix, is a discontinued Unix operating system developed and distributed by the Computer Systems Research Group (CSRG) at the University of California, Berkeley, beginni ...

. Under these systems different commands are used. The commands can create many kinds of file systems, including those used by DOS, Windows, and OS/2.

Implementations

The command is also available in

Intel Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California, and Delaware General Corporation Law, incorporated in Delaware. Intel designs, manufactures, and sells computer compo ...

ISIS-II, iRMX 86,

MetaComCo MetaComCo (MCC) was a computer systems software company started in 1981 and based in Bristol, England by Peter Mackeonis and Derek Budge. A division of Tenchstar, Ltd. MetaComCo's first product was an MBASIC compatible interpreter for IBM PCs, ...

TRIPOS TRIPOS (''TRIvial Portable Operating System'') is a computer operating system. Development started in 1976 at the Computer Laboratory of Cambridge University and it was headed by Dr. Martin Richards. The first version appeared in January 1978 a ...

AmigaDOS AmigaDOS is the disk operating system of the AmigaOS, which includes file systems, file and directory manipulation, the command-line interface, and file Redirection (computing), redirection. In AmigaOS 1.x, AmigaDOS is based on a TRIPOS port by ...

Zilog Zilog, Inc. is an American manufacturer of microprocessors, microcontrollers, and application-specific embedded System on a chip, system-on-chip (SoC) products. The company was founded in 1974 by Federico Faggin and Ralph Ungermann, who were soo ...

Z80-RIO,

Microware Microware Systems Corporation was an American software company based in Clive, Iowa, that produced the OS-9 real-time operating system. Microware Systems Corporation existed as a separate entity from 1977 until September 2001, when it was boug ...

OS-9 OS-9 is a family of real-time, process-based, multitasking, multi-user operating systems, developed in the 1980s, originally by Microware Systems Corporation for the Motorola 6809 microprocessor. It was purchased by Radisys Corp in 2001, a ...

, DR

FlexOS FlexOS is a discontinued modular real-time multiuser multitasking operating system ( RTOS) designed for computer-integrated manufacturing, laboratory, retail and financial markets. Developed by Digital Research's Flexible Automation Business ...

, TSL

PC-MOS PC-MOS/386 is a multi-user, multitasking computer operating system produced by The Software Link (TSL), announced at COMDEX in November 1986 for February 1987 release. PC-MOS/386, a successor to PC-MOS, can run many MS-DOS programs on the host ...

SpartaDOS X SpartaDOS X (or SpartaDOS 4.0) is a disk operating system for the Atari 8-bit computers that closely resembles MS-DOS. It was developed and sold by ICD in 1987-1993, and many years later picked up by the third-party community SpartaDOS X Upgrade ...

Datalight Datalight was a privately held software company specializing in power failsafe and high performance software for preserving data integrity in embedded systems. The company was founded in 1983 by Roy Sherrill, and its headquarters is in Bothell, W ...

ROM-DOS,

Toshiba is a Japanese multinational electronics company headquartered in Minato, Tokyo. Its diversified products and services include power, industrial and social infrastructure systems, elevators and escalators, electronic components, semiconductors ...

4690 OS 4690 Operating System (sometimes shortened to 4690 OS or 4690) is a specially designed point of sale (POS) operating system, originally sold by IBM. In 2012, IBM sold its retail business, including this product, to Toshiba, which assumed support. ...

PTS-DOS PTS-DOS (aka PTS/DOS) is a disk operating system, a DOS clone, developed in Russia by PhysTechSoft and Paragon Technology Systems. History and versions PhysTechSoft was formed in 1991 in Moscow, Russia by graduates and members of MIPT, inf ...

, SISNE plus, and in the DEC

RT-11 RT-11 (Real-time 11) is a discontinued small, low-end, single-user real-time operating system for the full line of Digital Equipment Corporation PDP-11 16-bit computers. RT-11 was first implemented in 1970. It was widely used for real-time compu ...

operating system.

Microsoft DOS and Windows

, the command is available in versions 1 and later. Optionally (by adding the /S, for "system" switch), format can also install a Volume Boot Record. With this option, Format writes bootstrap code to the first sector of the volume (and possibly elsewhere as well). Format always writes a

BIOS Parameter Block In computing, the BIOS parameter block, often shortened to BPB, is a data structure in the volume boot record (VBR) describing the physical layout of a data storage volume. On partitioned devices, such as hard disks, the BPB describes the volume ...

to the first sector, with or without the /S option. Another option (/Q) allows for what Microsoft calls "Quick Format". With this option the command will not perform steps 2 and 3 above. Format /Q does not alter data previously written to the media. Typing "format" with no parameters in MS-DOS 3.2 or earlier would automatically, without prompting the user, format the current drive; however in MS-DOS 3.3 and later it would simply produce the error: "required parameter missing".

DR/Novell DOS

DR DOS 6.0 includes an implementation of the command.

FreeDOS

The

FreeDOS FreeDOS (formerly PD-DOS) is a free software operating system for IBM PC compatible computers. It intends to provide a complete MS-DOS-compatible environment for running Legacy system, legacy software and supporting embedded systems. FreeDOS ca ...

version was developed by Brian E. Reifsnyder and is licensed under the GPL.

ReactOS

The ReactOS implementation is based on a free clone developed by

Mark Russinovich Mark Eugene Russinovich (born December 22, 1966) is a Spanish-born American software engineer and author who serves as CTO of Microsoft Azure. He was a cofounder of software producers Winternals before Microsoft acquired it in 2006. Early lif ...

for

Sysinternals Windows Sysinternals is a website that offers technical resources and utilities to manage, diagnose, troubleshoot, and monitor a Microsoft Windows environment. Originally, the Sysinternals website (formerly known as ntinternals) was created in 19 ...

in 1998. It is licensed under the GPL. It was adapted to ReactOS by Emanuele Aliberti in 1999 and supports

FAT32 File Allocation Table (FAT) is a file system developed for personal computers and was the default file system for the MS-DOS and Windows 9x operating systems. Originally developed in 1977 for use on floppy disks, it was adapted for use on ...

, FATX,

EXT2 ext2, or second extended file system, is a file system for the Linux kernel (operating system), kernel. It was initially designed by French software developer Rémy Card as a replacement for the extended file system (ext). Having been designed ...

, and

BtrFS Btrfs (pronounced as "better F S", "butter F S", "b-tree F S", or "B.T.R.F.S.") is a computer storage format that combines a file system based on the copy-on-write (COW) principle with a logical volume manager (distinct from Linux's LVM), d ...

filesystems.

Notes

The directory entries get filled with 0x00 since MS-DOS 1.25 and PC DOS 2.0. If the Format command line option /O is provided, the first byte of each directory entry is set to 0xE5h to create a FAT format usable by PC DOS 1.0- 1.1. However, not providing /O will significantly speed up directory searches under MS-DOS 1.25 and PC DOS 2.0 and higher. Older versions of MS-DOS, PC DOS, and

only supported the 0xE5 marker.

References

External links

Microsoft Windows XP Professional Product Documentation: "format"Open source FORMAT implementation that comes with MS-DOS v2.0MSKB255867: How to Use the Fdisk Tool and the Format Tool to Partition or Repartition a Hard Disk
{{Windows commands External DOS commands Hard disk software MSX-DOS commands OS/2 commands Windows commands