FreeDOS (formerly Free-DOS and PD-DOS) is a free operating system for IBM PC compatible computers. It intends to provide a complete DOS-compatible environment for running legacy software and supporting embedded systems.[6][not in citation given]

FreeDOS can be booted from a floppy disk or USB flash drive.[7][8] It is designed to run well under virtualization or x86 emulation.[9]

Unlike MS-DOS, FreeDOS is composed of free and open-source software, licensed under the terms of the GNU General Public License.[2][need quotation to verify] Therefore, its base distribution does not require license fees or royalties and creation of custom distributions is permitted. However, other packages which form part of the FreeDOS project include non-GPL software considered worth preserving, such as 4DOS, which is distributed under a modified MIT License.[10][not in citation given]


The FreeDOS project began 29 June 1994, after Microsoft announced it would no longer sell or support MS-DOS. Jim Hall who at the time was a student[11] posted a manifesto proposing the development of an open-source replacement.[12][not in citation given] 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.[13][14] There have been many official pre-release distributions of FreeDOS before the final FreeDOS 1.0 distribution.[3] GNU/DOS, an unofficial distribution of FreeDOS, was discontinued after version 1.0 was released.[15][16]


FreeDOS 1.1, released on 2 January 2012,[17] is available for download as a CD-ROM 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 as of November 2011 but with a newer, fuller 1.2.[18] The legacy version 1.0 (2006) consisted of two CDs, one of which was an 8MB install CD targeted at regular users and the other which was a larger 49MB live CD that also held the source code of the project.[18]

Commercial uses

FreeDOS is used by several companies:

  • Dell preloaded FreeDOS with their 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.[19]
  • HP provided FreeDOS as an option in its dc5750 desktops, Mini 5101 netbooks and Probook laptops.[20][21][22] FreeDOS is also used as bootable media for updating the BIOS firmware in HP systems.[23]
  • GRC's SpinRite 6, a hard drive maintenance and recovery program, includes FreeDOS.[24]
  • Intel's Solid-State Drive Firmware Update Tool loads the FreeDOS kernel.[25]

Non-commercial uses

FreeDOS is also used in multiple independent projects:

  • FUZOMA is a FreeDOS-based distribution that can boot from a floppy disk and converts older computers into educational tools for children.[26]
  • FED-UP is the Floppy Enhanced DivX Universal Player.[27]


FreeDOS Version History[3][28][29]
Version Status Codename Date
0.01 ALPHA None 16 September 1994
0.02 ALPHA None December 1994
0.03 ALPHA None January 1995
0.04 ALPHA None June 1995
0.05 ALPHA None 10 August 1996
0.06 ALPHA None November 1997
0.1 BETA Orlando 25 March 1998
0.2 BETA Marvin 28 October 1998
0.3 BETA Ventura 21 April 1999
0.4 BETA Lemur 9 April 2000
0.5 BETA Lara 10 August 2000
0.6 BETA Midnite 18 March 2001
0.7 BETA Spears 7 September 2001
0.8 BETA Nikita 7 April 2002
0.9 BETA None 28 September 2004
1.0 FINAL None 3 September 2006
1.1 FINAL None 2 January 2012
1.2 FINAL None 25 December 2016


FreeDOS itself requires a PC/XT machine with at least 640kB of memory.[30] 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 DPMI executables. It is also possible to run 32-bit DPMI executables using DOS extenders. The operating system has several improvements relative to MS-DOS, mostly involving support of newer standards and technologies that did not exist when Microsoft ended support for MS-DOS, such as internationalization, or the Advanced Power Management TSRs.[31][not in citation given] Furthermore, with use of HX DOS Extender, many Win32 console applications function properly in FreeDOS, as do some rare GUI programs, like QEMU and Bochs.[32]

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 processors, can not fully be run in 386 Enhanced Mode[33] except partially in experimental FreeDOS kernel 2037.[citation needed]

Problems running Windows result from Microsoft's efforts to prevent their products running on non-Microsoft DOS implementations.[34][not in citation given]

Windows 95, 98 and ME use a stripped down version of MS-DOS. FreeDOS cannot be used as a replacement because of undocumented interfaces between MS-DOS 7.0-8.0 and Windows 4.xx 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.[citation needed]

Windows NT and ReactOS

Windows NT-based operating systems, including Windows 2000, XP, Vista and 7 for desktops, and Windows Server 2003, 2008 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 file systems, which are used by MS-DOS and earlier versions of Windows; however, they typically use the NTFS (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,[35] or freeldr.ini equivalent for ReactOS.[36]

File systems

FreeDOS's default text editor—a clone of the MS-DOS Editor with added features

FAT32 is fully supported and is the preferred format for the boot drive.[37] Depending on the BIOS used, up to four LBA (Logical block addressing) hard disks up to 128 GB, or 2 TB, in size are supported.[38] 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.[citation needed] FreeDOS can also be used with a driver named LFNDOS to enable support for Windows 95-style long file names,[39] but most old programs before Win95 do not support LFNs even with driver loaded unless they have been recompiled. There is no planned support for NTFS, ext2 or exFAT, but there are several external third-party drivers available for that purpose. To access ext2fs, LTOOLS (counterpart to Mtools) can sometimes be used to copy data to and from ext2fs drives.[citation needed]


Blinky, the mascot of FreeDOS.

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

See also


  1. ^ "FreeDOS Spec". FreeDOS Wiki. Freedos. 2008-12-24. Retrieved 2017-02-09. 
  2. ^ a b c "The FreeDOS Project". SourceForge. 2006-05-21. Retrieved 2008-01-02. 
  3. ^ a b c FreeDOS History; freedos.org
  4. ^ Villani, Pat (1996). FreeDOS Kernel. Emeryville, CA, USA: Miller Freeman. ISBN 0-87930-436-7. 
  5. ^ "Software List » UTIL". FreeDOS. The FreeDOS Project. Retrieved 2014-06-06. 
  6. ^ "Main Page". FreeDOS Wiki. The FreeDOS Project. Retrieved 2017-02-09. 
  7. ^ Franske, Ben (2007-08-21). "Booting DOS from a USB flash drive". Archived from the original on February 18, 2010. Retrieved 2008-08-04. 
  8. ^ "How to Create a Bootable FreeDOS Floppy Disk". 2005-07-19. Retrieved 2008-08-04. 
  9. ^ Gallagher, Sean (2014-07-14). "Though "barely an operating system," DOS still matters (to some people)". ArsTechnica. Condé Nast. Retrieved 2017-02-09. But FreeDOS has become much more friendly to virtualization and hardware emulation—it's even the heart of the DOSEMU emulator 
  10. ^ "4DOS". FreeDOS. The FreeDOS Project. Retrieved 2014-06-06. 
  11. ^ Jim Hall interviewed on the TV show FLOSS weekly on the TWiT.tv network
  12. ^ Hall, Jim (1994-06-29). "PD-DOS project *announcement*". Newsgroupcomp.os.msdos.apps. Retrieved 2008-06-14. 
  13. ^ Hall, Jim (2002-03-25). "The past, present, and future of the FreeDOS Project". LinuxGizmos.com. Retrieved 2008-06-14. 
  14. ^ Hall, Jim (2006-09-23). "About". FreeDOS. The FreeDOS Project. Archived from the original on 2007-05-27. Retrieved 2014-06-17. 
  15. ^ Adams, David. "Introducing GNU/DOS 2005". OSNews. Retrieved 27 November 2016. 
  16. ^ Marinof, Mihai. "GNU/DOS Project Discontinued". Retrieved 27 November 2016. 
  17. ^ Hall, Jim (2012-01-02). "Announcement on official FreeDOS homepage". SourceForge. Retrieved 2012-01-02. 
  18. ^ a b "FreeDOS 1.0". FreeDOS.org. The FreeDOS Project. Archived from the original on 2011-11-05. Retrieved 2015-12-21. 
  19. ^ Vance, Ashlee. "How Dell repels attempts to buy its 'open source' PC". The Register. Retrieved 2008-01-02. 
  20. ^ "HP Compaq dc5750 Business PC". Hewlett-Packard. Archived from the original on 13 November 2012. Retrieved 27 November 2016. 
  21. ^ "First Look at HP's Low-Cost ProBook Laptop Lineup". EWeek. Retrieved 2009-03-26. 
  22. ^ McCracken, Harry (2009-06-23). "HP's Mini 5101: Netbook Deluxe, With All the Trimmings". Technologizer. Retrieved 2009-08-01. 
  23. ^ "FreeDOS Bootable Media". HP. 2010-10-25. Retrieved 2011-01-13. 
  24. ^ Leon A. Goldstein (2004-07-19). "SpinRite 6.0 for Linux Users". Linux Journal. Retrieved 2017-02-09. 
  25. ^ "Intel® SATA Solid-State Drive Firmware Update Tool". Intel. Archived from the original on 25 March 2010. Retrieved 27 November 2016. 
  26. ^ "FUZOMA Educational Software". Retrieved 2009-12-18. 
  27. ^ "Floppy Enhanced DivX Universal Player". Retrieved 2009-12-18. 
  28. ^ FreeDOS software package comparison; ibiblio.org
  29. ^ Jim Hall (2007-10-02). "Removing old distributions from ibiblio" (Mailing list). freedos-devel. Retrieved 2009-10-07. 
  30. ^ Lowe, Scott (2003-07-22). "Configure IT Quick: Use FreeDOS as a replacement for MS-DOS". TechRepublic. CBS Interactive. Retrieved 2017-02-09. 
  31. ^ Broersma, Matthew (September 4, 2006). "DOS lives! Open source reinvents past". Techworld. Archived from the original on November 2, 2013. 
  32. ^ Grech, Andreas. "HX DOS Extender". Archived from the original on October 3, 2014. 
  33. ^ Aitor (2014-09-03). "Windows on FreeDOS?". FreeDOS. Retrieved 2017-02-09. 
  34. ^ Lea, Graham (2000-01-13). "Caldera vs Microsoft - the settlement". BBC News. Retrieved 2009-01-02. 
  35. ^ Herbert, Marc (2004-10-01). "Install FreeDOS without any CD, floppy, USB-key, nor any other removable media". Retrieved 2009-05-26. 
  36. ^ "FreeLoader - ReactOS Wiki". reactos.org. Retrieved 2017-06-30. 
  37. ^ Hilpert, Dominik (2015-05-07). "Creating a Bootable DOS USB Stick". Retrieved 2017-02-09. 
  38. ^ Mueller, Scott (2013-03-22). Upgrading and Repairing PCs, 21st Edition. Que Publishing. 
  39. ^ Gallagher, Sean (2014-07-03). "Old school: I work in DOS for an entire day". ArsTechnica. Condé Nast. Retrieved 2017-02-09. 

External links