FreeDOS (formerly PD-DOS) is a

free software Free software, libre software, libreware sometimes known as freedom-respecting software is computer software distributed open-source license, under terms that allow users to run the software for any purpose as well as to study, change, distribut ...

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 ...

for

IBM PC compatible An IBM PC compatible is any personal computer that is hardware- and software-compatible with the IBM Personal Computer (IBM PC) and its subsequent models. Like the original IBM PC, an IBM PC–compatible computer uses an x86-based central p ...

computers. It intends to provide a complete

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 ...

-compatible environment for running

legacy software Legacy or Legacies may refer to: Arts and entertainment Comics * " Batman: Legacy", a 1996 Batman storyline * '' DC Universe: Legacies'', a comic book series from DC Comics * ''Legacy'', a 1999 quarterly series from Antarctic Press * ''Legacy ...

and supporting

embedded system An embedded system is a specialized computer system—a combination of a computer processor, computer memory, and input/output peripheral devices—that has a dedicated function within a larger mechanical or electronic system. It is e ...

s. FreeDOS can be booted from 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 ...

USB flash drive A flash drive (also thumb drive, memory stick, and pen drive/pendrive) is a data storage device that includes flash memory with an integrated USB interface. A typical USB drive is removable, rewritable, and smaller than an optical disc, and u ...

and is designed to run well under

virtualization In computing, virtualization (abbreviated v12n) is a series of technologies that allows dividing of physical computing resources into a series of virtual machines, operating systems, processes or containers. Virtualization began in the 1960s wit ...

x86 x86 (also known as 80x86 or the 8086 family) is a family of complex instruction set computer (CISC) instruction set architectures initially developed by Intel, based on the 8086 microprocessor and its 8-bit-external-bus variant, the 8088. Th ...

emulation. The FreeDOS project began under Jim Hall in 1994, and the first

stable A stable is a building in which working animals are kept, especially horses or oxen. The building is usually divided into stalls, and may include storage for equipment and feed. Styles There are many different types of stables in use tod ...

version was released in 2006. Unlike most versions of

, FreeDOS is composed of

, licensed under the terms of the

GNU General Public License The GNU General Public Licenses (GNU GPL or simply GPL) are a series of widely used free software licenses, or ''copyleft'' licenses, that guarantee end users the freedom to run, study, share, or modify the software. The GPL was the first ...

. However, other packages that form part of the FreeDOS project include non-GPL software considered worthy of

preservation Preservation may refer to: Heritage and conservation * Preservation (library and archival science), activities aimed at prolonging the life of a record while making as few changes as possible * ''Preservation'' (magazine), published by the Nat ...

, such as

4DOS 4DOS is a command-line interpreter by JP Software, designed to replace the default command interpreter COMMAND.COM in MS-DOS and Windows. It was written by Rex C. Conn and Tom Rawson and first released in 1989. Compared to the default, it has ...

, which is distributed under a modified

MIT License The MIT License is a permissive software license originating at the Massachusetts Institute of Technology (MIT) in the late 1980s. As a permissive license, it puts very few restrictions on reuse and therefore has high license compatibility. Unl ...

Distribution

FreeDOS 1.1, released on 2 January 2012, is available for download as a

CD-ROM A CD-ROM (, compact disc read-only memory) is a type of read-only memory consisting of a pre-pressed optical compact disc that contains computer data storage, data computers can read, but not write or erase. Some CDs, called enhanced CDs, hold b ...

image: a limited install disc that only contains the kernel and basic applications, and a full disc that contains many more applications (games, networking, development, etc.), not available but with a newer, fuller 1.2. The legacy version 1.0 (2006) consisted of two CDs, one of which was an 8 MB install CD targeted at regular users and the other which was a larger 49 MB live CD that also held the source code of the project.

Commercial uses

FreeDOS is used by several companies: *

Dell Dell Inc. is an American technology company that develops, sells, repairs, and supports personal computers (PCs), Server (computing), servers, data storage devices, network switches, software, computer peripherals including printers and webcam ...

preloaded FreeDOS with its n-series desktops to reduce their cost. The firm has been criticized for making these machines no cheaper, and harder to buy, than identical systems with Windows. *

Hewlett-Packard The Hewlett-Packard Company, commonly shortened to Hewlett-Packard ( ) or HP, was an American multinational information technology company. It was founded by Bill Hewlett and David Packard in 1939 in a one-car garage in Palo Alto, California ...

provided FreeDOS as an option in its HP Compaq dc5750 Small Form Factor PC, ''Mini 5101'' netbooks and ''Probook'' laptops. FreeDOS is also used as bootable media for updating the BIOS

firmware In 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, h ...

in HP systems. * FreeDOS is included by Steve Gibson's hard drive maintenance and recovery program, SpinRite. * Intel's Solid-State Drive Firmware Update Tool loaded the FreeDOS kernel. * Many motherboard vendors recommend a bootable FreeDOS for running low level BIOS and firmware updates.

Non-commercial uses

FreeDOS is also used in multiple independent projects: * FED-UP is the Floppy Enhanced

DivX DIVX (Digital Video Express) is a discontinued digital video format. Created in part by Circuit City, it was an unsuccessful attempt to create an alternative to video rental in the United States. The format's poor reception from consumers resu ...

Universal Player. * FUZOMA is a FreeDOS-based distribution that can boot from a

and converts older computers into educational tools for children. * XFDOS is a FreeDOS-based distribution with a

graphical user interface A graphical user interface, or GUI, is a form of user interface that allows user (computing), users to human–computer interaction, interact with electronic devices through Graphics, graphical icon (computing), icons and visual indicators such ...

, porting Nano-X and FLTK.

Development and version history

The FreeDOS project began on 29 June 1994, after

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 ...

announced it would no longer sell or support MS-DOS. Jim Hall, who at the time was a student, posted a manifesto proposing the development of PD-DOS, a

public domain The public domain (PD) consists of all the creative work to which no Exclusive exclusive intellectual property rights apply. Those rights may have expired, been forfeited, expressly Waiver, waived, or may be inapplicable. Because no one holds ...

version of DOS. Within a few weeks, other programmers including Pat Villani and Tim Norman joined the project. Between them, a kernel (by Villani), the COMMAND.COM command line interpreter (by Villani and Norman), and core utilities (by Hall) were created by pooling code they had written or found available. For some time, the project was maintained by Morgan "Hannibal" Toal. There have been many official pre-release distributions of FreeDOS before the final FreeDOS 1.0 distribution. GNU/DOS, an unofficial distribution of FreeDOS, was discontinued after version 1.0 was released. Blinky

Blinky the Fish is the mascot of FreeDOS. He was designed by Bas Snabilie.

Compatibility

Hardware

FreeDOS requires a PC/XT machine with at least 640 kB of memory. Programs not bundled with FreeDOS often require additional system resources.

MS-DOS and Win32 console

FreeDOS is mostly compatible with MS-DOS. It supports COM executables, standard DOS executables and Borland's

16-bit 16-bit microcomputers are microcomputers that use 16-bit microprocessors. A 16-bit register can store 216 different values. The range of integer values that can be stored in 16 bits depends on the integer representation used. With the two ...

DPMI executables. It is also possible to run

32-bit In computer architecture, 32-bit computing refers to computer systems with a processor, memory, and other major system components that operate on data in a maximum of 32- bit units. Compared to smaller bit widths, 32-bit computers can perform la ...

DPMI executables using

DOS extender A DOS extender is a computer software program running under DOS that enables software to run in a protected mode environment even though the host operating system is only capable of operating in real mode. DOS extenders were initially developed ...

s. The operating system has several improvements relative to MS-DOS, mostly involving support for newer standards and technologies that did not exist when Microsoft ended support for MS-DOS, such as

internationalization Internationalization or Internationalisation is the process of increasing involvement of enterprises in international markets, although there is no agreed definition of internationalization. Internationalization is a crucial strategy not only for ...

, or the

Advanced Power Management Advanced power management (APM) is a technical standard for power management developed by Intel and Microsoft and released in 1992 which enables an operating system running an IBM-compatible personal computer to work with the BIOS (part of the com ...

TSRs. Furthermore, with the use of HX DOS Extender, many Windows Console applications function properly in FreeDOS, as do some rare GUI programs, like QEMM and Bochs.

DOS-based Windows

FreeDOS is able to run Microsoft Windows 1.0 and 2.0 releases. Windows 3.x releases, which had support for

i386 The Intel 386, originally released as the 80386 and later renamed i386, is the third-generation x86 architecture microprocessor from Intel. It was the first 32-bit processor in the line, making it a significant evolution in the x86 archite ...

processors, cannot fully be run in 386 Enhanced Mode, except partially in the experimental FreeDOS kernel 2037.

Windows 95 Windows 95 is a consumer-oriented operating system developed by Microsoft and the first of its Windows 9x family of operating systems, released to manufacturing on July 14, 1995, and generally to retail on August 24, 1995. Windows 95 merged ...

Windows 98 Windows 98 is a consumer-oriented operating system developed by Microsoft as part of its Windows 9x family of Microsoft Windows operating systems. It was the second operating system in the 9x line, as the successor to Windows 95. It was Software ...

and

Windows Me Windows Me (Millennium Edition) is an operating system developed by Microsoft as part of its Windows 9x family of Microsoft Windows operating systems. It was the successor to Windows 98, and was released to manufacturing on June 19, 2000, and t ...

use a stripped-down version of MS-DOS. FreeDOS cannot be used as a replacement because the undocumented interfaces between MS-DOS 7.0–8.0 and Windows "4.xx" are not emulated by FreeDOS; however, it can be installed and used beside these systems using a boot manager program, such as BOOTMGR or METAKERN included with FreeDOS.

Windows NT and ReactOS

Windows NT Windows NT is a Proprietary software, proprietary Graphical user interface, graphical operating system produced by Microsoft as part of its Windows product line, the first version of which, Windows NT 3.1, was released on July 27, 1993. Original ...

-based operating systems, including

Windows 2000 Windows 2000 is a major release of the Windows NT operating system developed by Microsoft, targeting the server and business markets. It is the direct successor to Windows NT 4.0, and was Software release life cycle#Release to manufacturing (RT ...

, XP, Vista, 7, 8, 8.1, 10 and 11 for desktops, and

Windows Server 2003 Windows Server 2003, codenamed "Whistler Server", is the sixth major version of the Windows NT operating system produced by Microsoft and the first server version to be released under the Windows Server brand name. It is part of the Windows NT ...

2008 2008 was designated as: *International Year of Languages *International Year of Planet Earth *International Year of the Potato *International Year of Sanitation The Great Recession, a worldwide recession which began in 2007, continued throu ...

and 2008 R2 for servers, do not make use of MS-DOS as a core component of the system. These systems can make use of 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 ...

file systems which are used by MS-DOS and earlier versions of

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 ...

; however, they typically use the

NTFS NT File System (NTFS) (commonly called ''New Technology File System'') is a proprietary journaling file system developed by Microsoft in the 1990s. It was developed to overcome scalability, security and other limitations with File Allocation Tabl ...

(New Technology File System) by default for security and other reasons. FreeDOS can co-exist on these systems on a separate partition or on the same partition on FAT systems. The FreeDOS kernel can be booted by adding it to the Windows 2000 or XP's NT Boot Loader configuration file,

boot.ini NTLDR (abbreviation of ''NT loader'') is the Booting, boot loader for all releases of Windows NT operating system from 1993 with the release of Windows NT 3.1 up until Windows XP and Windows Server 2003. From Windows Vista onwards it was replaced b ...

, or the freeldr.ini equivalent for

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 ...

Virtualization

FreeDOS is designed to work well with virtualization software such as VirtualBox and VMware. The installation process is identical to real hardware. It is also possible to install FreeDOS on

DOSBox DOSBox is a free and open-source MS-DOS emulator. It supports running programs primarily video games that are otherwise inaccessible since hardware for running a compatible disk operating system (DOS) is obsolete and generally unavailab ...

and its derivatives. By doing so, it provides additional functionality not present in the emulator.

File systems

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 ...

is fully supported and is the preferred format for the boot drive. Depending on the

BIOS In computing, BIOS (, ; Basic Input/Output System, also known as the System BIOS, ROM BIOS, BIOS ROM or PC BIOS) is a type of firmware used to provide runtime services for operating systems and programs and to perform hardware initialization d ...

used, up to four

Logical Block Addressing Logical block addressing (LBA) is a common scheme used for specifying the location of blocks of data stored on computer storage devices, generally secondary storage systems such as hard disk drives. LBA is a particularly simple linear addressin ...

(LBA) hard disks of up to 128 GB, or 2 TB, in size are supported. There has been little testing with large disks, and some BIOSes support LBA, but produce errors on disks larger than 32 GB; a driver such as OnTrack or EZ-Drive resolves this problem. FreeDOS can also be used with a driver called LFNDOS to enable support for Windows 95-style long file names, but most pre-Windows 95 programs do not support long file names, even with a driver loaded. There is no planned support for NTFS,

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 ...

or exFAT, but there are several external third-party drivers available for that purpose. To access ext2 file systems, LTOOLS, a counterpart to Mtools, can sometimes be used to copy data to and from ext2 file system drives.

References

External links

* *
FreeDOS Orphanage
{{DEFAULTSORT:Freedos 1998 software DOS variants Embedded operating systems Floppy disk-based operating systems Free software operating systems Free software programmed in C Microcomputer software Operating system distributions bootable from read-only media Software using the GNU General Public License