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format (command)
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<h2 id="overview">Overview</h2> <p>The <a href="/facts/Command_(computing)/zUrvQbFy">command</a> performs the following actions by default on a <a href="/facts/Floppy_disk/rShxfuxa">floppy disk</a>, <a href="/facts/Hard_disk_drive/kekLSGSE">hard disk drive</a>, <a href="/facts/Solid-state_drive/aMHBy8gU">solid state</a> (<a href="/facts/USB/XcIKWLyg">USB</a>), or other <a href="/facts/Magnetic_medium/QaK6oArm">magnetic medium</a> (it will not perform these actions on <a href="/facts/Optical_disc/vjVDB1GH">optical media</a>): </p> <ol><li>clearing the <a href="/facts/Design_of_the_FAT_file_system/UIMFFkCm">FAT</a> entries by changing them to 0x00</li> <li>clearing the <a href="/facts/FAT_root_directory/UIMFFkCm">FAT root directory</a> by changing any values found to 0x00<a class="footnote-ref" id="fnref:1" href="#fn:1"><sup>1</sup></a><a class="footnote-ref" id="fnref:2" href="#fn:2"><sup>2</sup></a><a class="footnote-ref" id="fnref:3" href="#fn:3"><sup>3</sup></a><a class="footnote-ref" id="fnref:4" href="#fn:4"><sup>4</sup></a></li> <li>checking each <a href="/facts/Cluster_(file_system)/zDruC5lW">cluster</a> to see if it is good or bad and marking it as good or bad in the FAT</li></ol> <p>Any <a href="/facts/Data_storage_device/uCvJ6nrq">storage device</a> must have its medium structured to be useful. This process is referred to as "creating a filesystem" in <a href="/facts/Unix/0pNL2seI">Unix</a>, <a href="/facts/Linux/9FvCKSTq">Linux</a>, or <a href="/facts/BSD/XQKcURrh">BSD</a>.<a class="footnote-ref" id="fnref:5" href="#fn:5"><sup>5</sup></a> Under these systems different commands are used. The commands can create many kinds of <a href="/facts/File_system/FdPm90uc">file systems</a>, including those used by DOS, Windows, and OS/2. </p> <h2 id="implementations">Implementations</h2> <p>The command is also available in <a href="/facts/Intel/SMF0gJJX">Intel</a> <a href="/facts/ISIS_(operating_system)/xJMURtnq">ISIS-II</a>,<a class="footnote-ref" id="fnref:6" href="#fn:6"><sup>6</sup></a> <a href="/facts/RMX_(operating_system)/wXBPoFsh">iRMX 86</a>,<a class="footnote-ref" id="fnref:7" href="#fn:7"><sup>7</sup></a> <a href="/facts/MetaComCo/2mq2Jlb3">MetaComCo</a> <a href="/facts/TRIPOS/Wrj0r0ma">TRIPOS</a>,<a class="footnote-ref" id="fnref:8" href="#fn:8"><sup>8</sup></a> <a href="/facts/AmigaDOS/D3AXdf2m">AmigaDOS</a>,<a class="footnote-ref" id="fnref:9" href="#fn:9"><sup>9</sup></a> <a href="/facts/Zilog/sB6jH5vw">Zilog</a> <a href="/facts/Z80-RIO/LTEUl0KU">Z80-RIO</a>,<a class="footnote-ref" id="fnref:10" href="#fn:10"><sup>10</sup></a> <a href="/facts/Microware/voC4tGPv">Microware</a> <a href="/facts/OS-9/6dYWMW3f">OS-9</a>,<a class="footnote-ref" id="fnref:11" href="#fn:11"><sup>11</sup></a> <a href="/facts/Digital_Research/9bYQl2pI">DR</a> <a href="/facts/FlexOS/563z8WWo">FlexOS</a>,<a class="footnote-ref" id="fnref:12" href="#fn:12"><sup>12</sup></a> <a href="/facts/The_Software_Link/43yMylCR">TSL</a> <a href="/facts/PC-MOS/4HyyxdDa">PC-MOS</a>,<a class="footnote-ref" id="fnref:13" href="#fn:13"><sup>13</sup></a> <a href="/facts/SpartaDOS_X/L0Xuh48E">SpartaDOS X</a>,<a class="footnote-ref" id="fnref:14" href="#fn:14"><sup>14</sup></a> <a href="/facts/Datalight/I6X8HJNC">Datalight</a> <a href="/facts/ROM-DOS/I6X8HJNC">ROM-DOS</a>,<a class="footnote-ref" id="fnref:15" href="#fn:15"><sup>15</sup></a> <a href="/facts/IBM/QszA7nwd">IBM</a>/<a href="/facts/Toshiba/QHRaw8Tr">Toshiba</a> <a href="/facts/4690_Operating_System/wEIsvjtF">4690 OS</a>,<a class="footnote-ref" id="fnref:16" href="#fn:16"><sup>16</sup></a> <a href="/facts/PTS-DOS/5LsVelfc">PTS-DOS</a>,<a class="footnote-ref" id="fnref:17" href="#fn:17"><sup>17</sup></a> <a href="/facts/SISNE_plus/pbuF6osk">SISNE plus</a>,<a class="footnote-ref" id="fnref:18" href="#fn:18"><sup>18</sup></a> and in the <a href="/facts/Digital_Equipment_Corporation/ztxs6keA">DEC</a> <a href="/facts/RT-11/AXaahzdB">RT-11</a><a class="footnote-ref" id="fnref:19" href="#fn:19"><sup>19</sup></a> operating system. </p> <h3>Microsoft DOS and Windows</h3> <p>On <a href="/facts/MS-DOS/fVrrz1uN">MS-DOS</a>, the command is available in versions 1 and later.<a class="footnote-ref" id="fnref:20" href="#fn:20"><sup>20</sup></a> </p><p>Optionally (by adding the /S, for "system" switch), format can also install a <a href="/facts/Volume_Boot_Record/yLef5Tvg">Volume Boot Record</a>. With this option, Format writes bootstrap code to the first sector of the volume (and possibly elsewhere as well). Format always writes a <a href="/facts/BIOS_Parameter_Block/pRQGRRsC">BIOS Parameter Block</a> to the first sector, with or without the /S option. </p><p>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. </p><p>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". </p> <h3>DR/Novell DOS</h3> <p><a href="/facts/DR_DOS_6.0/GcCTKutW">DR DOS 6.0</a> includes an implementation of the format command.<a class="footnote-ref" id="fnref:21" href="#fn:21"><sup>21</sup></a> </p> <h3>FreeDOS</h3> <p>The <a href="/facts/FreeDOS/61fuGd0j">FreeDOS</a> version was developed by Brian E. Reifsnyder and is licensed under the <a href="/facts/GNU_General_Public_License/S75KhLSX">GPL</a>.<a class="footnote-ref" id="fnref:22" href="#fn:22"><sup>22</sup></a> </p> <h3>ReactOS</h3> <p>The ReactOS implementation is based on a <a href="/facts/Free_software/IaoVtJXn">free</a> clone developed by <a href="/facts/Mark_Russinovich/xutjgFN2">Mark Russinovich</a> for <a href="/facts/Sysinternals/74MuzdnW">Sysinternals</a> in 1998. It is licensed under the GPL.<a class="footnote-ref" id="fnref:23" href="#fn:23"><sup>23</sup></a> It was adapted to ReactOS by Emanuele Aliberti in 1999 and supports <a href="/facts/File_Allocation_Table/uFvpmWxa">FAT</a>, <a href="/facts/FAT32/uFvpmWxa">FAT32</a>, <a href="/facts/FATX/uFvpmWxa">FATX</a>, <a href="/facts/Ext2/ftyVw4Kv">EXT2</a>, and <a href="/facts/BtrFS/lPwmXVJ6">BtrFS</a> filesystems. </p> <h2 id="see-also">See also</h2> <ul><li><a href="/facts/Disk_formatting/VsSsjdwP">Disk formatting</a></li> <li><a href="/facts/Data_recovery/KvNG11I1">Data recovery</a></li> <li><a href="/facts/Convert_(command)/7uYEQIdX">convert</a></li> <li><a href="/facts/File_Allocation_Table/uFvpmWxa">File Allocation Table</a></li> <li><a href="/facts/Design_of_the_FAT_file_system/UIMFFkCm">Design of the FAT file system</a></li> <li><a href="/facts/Fdisk/S6hru6n4">fdisk</a></li> <li><a href="/facts/PC_DOS_7.10/ScsfqAwQ">PC DOS 7.10</a> Format32</li></ul> <h2 id="notes">Notes</h2> <h2 id="further-reading">Further reading</h2> <ul><li>Cooper, Jim (2001). <i>Special Edition Using MS-DOS 6.22, Third Edition</i>. <a href="/facts/Que_Publishing/UNq9rds8">Que Publishing</a>. <a href="/facts/ISBN_(identifier)/15AdSPa9">ISBN</a> 978-0789725738.</li> <li>Kathy Ivens; Brian Proffit (1993). <i>OS/2 Inside & Out</i>. <a href="/facts/Osborne_McGraw-Hill/srSyQSsY">Osborne McGraw-Hill</a>. <a href="/facts/ISBN_(identifier)/15AdSPa9">ISBN</a> 978-0078818714.</li> <li>Frisch, Æleen (2001). <i>Windows 2000 Commands Pocket Reference</i>. <a href="/facts/O%27Reilly_Media/Fr3Kv7sm">O'Reilly</a>. <a href="/facts/ISBN_(identifier)/15AdSPa9">ISBN</a> 978-0-596-00148-3.</li></ul> <h2 id="external-links">External links</h2> Wikibooks has a book on the topic of: <i>Guide to Windows Commands</i> <ul><li><a href="http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/format.mspx">Microsoft Windows XP Professional Product Documentation: "format"</a></li> <li><a href="https://github.com/microsoft/MS-DOS/blob/master/v2.0/source/FORMAT.ASM">Open source FORMAT implementation that comes with MS-DOS v2.0</a></li> <li><a href="http://support.microsoft.com/kb/255867">MSKB255867: How to Use the Fdisk Tool and the Format Tool to Partition or Repartition a Hard Disk</a></li> <li><a href="http://www.computerhope.com/formathl.htm">Microsoft DOS format command</a></li> <li><a href="http://pcsupport.about.com/od/termsf/p/format-rc.htm">Recovery Console format command</a> <a href="https://web.archive.org/web/20110707075247/http://pcsupport.about.com/od/termsf/p/format-rc.htm">Archived</a> 2011-07-07 at the <a href="/facts/Wayback_Machine/nmQ3a6JC">Wayback Machine</a></li></ul> <h2 id="references">References</h2> <ol> <li id="fn:1"><p>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 86-DOS only supported the 0xE5 marker. <a href="/wiki/MS-DOS_1.25" target="_blank">/wiki/MS-DOS_1.25</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li> <li id="fn:2"><p>Paterson, Tim (2013-12-19) [1983]. "Microsoft DOS V1.1 and V2.0: /msdos/v20source/FORMAT.TXT". Computer History Museum, Microsoft. Archived from the original on 2019-08-14. Retrieved 2014-03-25. (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.) <a href="/wiki/Tim_Paterson" target="_blank">/wiki/Tim_Paterson</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li> <li id="fn:3"><p>Shustek, Len (2014-03-24). "Microsoft MS-DOS early source code". Software Gems: The Computer History Museum Historical Source Code Series. Archived from the original on 2019-08-10. Retrieved 2014-03-29. (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.) <a href="http://www.computerhistory.org/atchm/microsoft-ms-dos-early-source-code/" target="_blank">http://www.computerhistory.org/atchm/microsoft-ms-dos-early-source-code/</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li> <li id="fn:4"><p>Levin, Roy (2014-03-25). "Microsoft makes source code for MS-DOS and Word for Windows available to public". Official Microsoft Blog. Archived from the original on 2014-03-28. Retrieved 2014-03-29. (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.) <a href="https://web.archive.org/web/20140328094124/http://blogs.technet.com/b/microsoft_blog/archive/2014/03/25/microsoft-makes-source-code-for-ms-dos-and-word-for-windows-available-to-public.aspx" target="_blank">https://web.archive.org/web/20140328094124/http://blogs.technet.com/b/microsoft_blog/archive/2014/03/25/microsoft-makes-source-code-for-ms-dos-and-word-for-windows-available-to-public.aspx</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li> <li id="fn:5"><p>newfs(8): EXAMPLE section – FreeBSD System Manager's Manual <a href="https://www.freebsd.org/cgi/man.cgi?query=newfs&sektion=8" target="_blank">https://www.freebsd.org/cgi/man.cgi?query=newfs&sektion=8</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></p></li> <li id="fn:6"><p>"ISIS II Users Guide" (PDF). Archived (PDF) from the original on 2019-01-26. Retrieved 2019-02-03. <a href="http://bitsavers.org/pdf/intel/ISIS_II/9800306-06_ISIS-II_Users_Guide_May81.pdf" target="_blank">http://bitsavers.org/pdf/intel/ISIS_II/9800306-06_ISIS-II_Users_Guide_May81.pdf</a> <a href="#fnref:6" class="footnote-back-ref">↩</a></p></li> <li id="fn:7"><p>"intel :: iRMX :: 146194-001 irmxR6Intro" – via Internet Archive. <a href="https://archive.org/details/bitsavers_inteliRMX1_19819263" target="_blank">https://archive.org/details/bitsavers_inteliRMX1_19819263</a> <a href="#fnref:7" class="footnote-back-ref">↩</a></p></li> <li id="fn:8"><p>https://www.pagetable.com/docs/amigados_tripos/tripos_manuals.pdf Archived 2020-10-21 at the Wayback Machine [bare URL PDF] <a href="https://www.pagetable.com/docs/amigados_tripos/tripos_manuals.pdf" target="_blank">https://www.pagetable.com/docs/amigados_tripos/tripos_manuals.pdf</a> <a href="#fnref:8" class="footnote-back-ref">↩</a></p></li> <li id="fn:9"><p>Rugheimer, Hannes (1988). Quick reference. Abacus. ISBN 9781557550491. Retrieved 2020-09-14 – via archive.org. <a href="9781557550491" target="_blank">9781557550491</a> <a href="#fnref:9" class="footnote-back-ref">↩</a></p></li> <li id="fn:10"><p>"Z80-RIO OPERATING SYSTEM USER'S MANUAL" (PDF). Archived (PDF) from the original on 2022-01-28. Retrieved 2020-02-14. <a href="https://www.z80cpu.eu/mirrors/oldcomputers.dyndns.org/public/pub/rechner/zilog/zds/z80-rio_os_userman.pdf" target="_blank">https://www.z80cpu.eu/mirrors/oldcomputers.dyndns.org/public/pub/rechner/zilog/zds/z80-rio_os_userman.pdf</a> <a href="#fnref:10" class="footnote-back-ref">↩</a></p></li> <li id="fn:11"><p>Paul S. Dayan (1992). The OS-9 Guru - 1 : The Facts. Galactic Industrial Limited. ISBN 0-9519228-0-7. <a href="0-9519228-0-7" target="_blank">0-9519228-0-7</a> <a href="#fnref:11" class="footnote-back-ref">↩</a></p></li> <li id="fn:12"><p>"FlexOS User's Guide" (PDF). www.bitsavers.org. 1986. Archived from the original (PDF) on 2019-09-25. Retrieved 2020-09-14. <a href="https://web.archive.org/web/20190925131719/http://bitsavers.org/pdf/digitalResearch/flexos/1073-2003_FlexOS_Users_Guide_V1.3_Nov86.pdf" target="_blank">https://web.archive.org/web/20190925131719/http://bitsavers.org/pdf/digitalResearch/flexos/1073-2003_FlexOS_Users_Guide_V1.3_Nov86.pdf</a> <a href="#fnref:12" class="footnote-back-ref">↩</a></p></li> <li id="fn:13"><p>"roelandjansen/pcmos386v501". GitHub. 2 January 2022. Archived from the original on 4 May 2021. Retrieved 28 July 2019. <a href="https://github.com/roelandjansen/pcmos386v501" target="_blank">https://github.com/roelandjansen/pcmos386v501</a> <a href="#fnref:13" class="footnote-back-ref">↩</a></p></li> <li id="fn:14"><p>"SpartaDOS X 4.48 User Guide" (PDF). Archived (PDF) from the original on 2021-10-10. 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Archived (PDF) from the original on 2018-05-12. Retrieved 2018-05-12. <a href="http://download.paragon-software.com/doc/manual_dos_eng.pdf" target="_blank">http://download.paragon-software.com/doc/manual_dos_eng.pdf</a> <a href="#fnref:17" class="footnote-back-ref">↩</a></p></li> <li id="fn:18"><p>"SISNE plus - Referência Sumária". Datassette. May 14, 2015. Archived from the original on September 28, 2019. Retrieved September 28, 2019. <a href="https://datassette.org/manuais/ibm-pc/sisne-plus-referencia-sumaria" target="_blank">https://datassette.org/manuais/ibm-pc/sisne-plus-referencia-sumaria</a> <a href="#fnref:18" class="footnote-back-ref">↩</a></p></li> <li id="fn:19"><p>"RT-11 HELP FILE". paleoferrosaurus.com. Archived from the original on 2018-07-17. Retrieved 2018-07-16. <a href="https://web.archive.org/web/20180717041552/http://paleoferrosaurus.com/beta/documents/rt11help.html#FORMAT" target="_blank">https://web.archive.org/web/20180717041552/http://paleoferrosaurus.com/beta/documents/rt11help.html#FORMAT</a> <a href="#fnref:19" class="footnote-back-ref">↩</a></p></li> <li id="fn:20"><p>Wolverton, Van (2003). Running MS-DOS Version 6.22 (20th Anniversary Edition), 6th Revised edition. Microsoft Press. ISBN 0-7356-1812-7. <a href="0-7356-1812-7" target="_blank">0-7356-1812-7</a> <a href="#fnref:20" class="footnote-back-ref">↩</a></p></li> <li id="fn:21"><p>"DR DOS 6.0 User Guide Optimisation and Configuration Tips" (PDF). Archived (PDF) from the original on 2019-09-30. Retrieved 2019-08-12. <a href="https://www.4corn.co.uk/archive/docs/DR%20DOS%206.0%20User%20Guide-opt.pdf" target="_blank">https://www.4corn.co.uk/archive/docs/DR%20DOS%206.0%20User%20Guide-opt.pdf</a> <a href="#fnref:21" class="footnote-back-ref">↩</a></p></li> <li id="fn:22"><p>"ibiblio.org FreeDOS Package -- Format (FreeDOS Base)". www.ibiblio.org. Archived from the original on 2018-11-19. Retrieved 2018-11-13. <a href="http://www.ibiblio.org/pub/micro/pc-stuff/freedos/files/distributions/1.2/repos/pkg-html/format.html" target="_blank">http://www.ibiblio.org/pub/micro/pc-stuff/freedos/files/distributions/1.2/repos/pkg-html/format.html</a> <a href="#fnref:22" class="footnote-back-ref">↩</a></p></li> <li id="fn:23"><p>"reactos/reactos". GitHub. 3 January 2022. Archived from the original on 11 December 2017. 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