Command: format

  FORMAT formats a hard drive or floppy disk. This prepares the medium
  for the use with FreeDOS. FDISK is not needed for floppy disks!


  Simplified syntax:
    FORMAT drive [/V[:label]] [/Q] [/U] [/F:size] [/S] [/D]
    FORMAT drive [/V[:label]] [/Q] [/U] [/T:tracks /N:sectors] [/S] [/D]
    FORMAT drive [/V[:label]] [/Q] [/U] [/4] [/S] [/D]
    FORMAT [/?]
  Full syntax (including new features and backwards compatibility
  Harddisk drives:
    FORMAT drive: [/V[:label]] [/Q] [/U] [/Z:seriously]
                  [/S] [/A] [/D] [/Y]
  New features, all drives:
    FORMAT drive: [/Z:mirror | /Z:unformat] [/D] [/Y]
  Floppy disk drives:
    FORMAT drive: [/V[:label]] [/Q] [/U] [/F:size]
                  [/B | /S] [/D] [/Y]
    FORMAT drive: [/V[:label]] [/Q] [/U] [/T:cyls /N:sect]
                  [/B | /S] [/D] [/Y]
    FORMAT drive: [/V[:label]] [/Q] [/U] [/1] [/4]
                  [/B | /S] [/D] [/Y]
  Old DOS 1.x floppy disks:
    FORMAT drive: /8 [/Q] [/U] [/1] [/4] [/B | /S] [/D] [/Y]

         drive  The drive letter, e.g. C:


  /1            Format a single-sided floppy disk (160k/180k).
  /4            Format a 160k/360k floppy disk in a 1.2 MB floppy drive.
                As 1.2 MB uses narrower tracks, format can be too weak
                for 360k drives.
  /8            Format a 5-1/4 inch floppy disk with 8 sectors per track
                (160k/320k, DOS 1.x).
  /A            Force metadata (reserved/boot sectors and FAT32s
                together) to be a multiple of 4k in size. The NTFS
                converter of WinXP wants that.
  /B            Reserve space to make a bootable disk (is dummy and
                cannot be combined with /s (SYS).
  /D            Be very verbose and show DEBUGGING output. For bug
                reports (always allowed). This even changes the returned
                error levels to be more "verbose".
  /F:size       Specifies the size of the floppy disk to format. Normal
                sizes are: 160, 180, 320, 360, 720, 1200, 1440, or 2880.
                To format to 720k in a drive which can do 1440k or more,
                you must use 720k DD media. /F shows a list of allowed
  /N:sectors    Specifies the number of sectors per track on a floppy
  /Q            Quick formats the disk. The disk can be UNFORMATed and
                the bad cluster list is preserved (not preserved in
                /Q /U mode). This is the default if an existing
                filesystem is found.
  /Q /U         Quick formats the disk but does NOT preserve unformat
                data and does NOT wipe or scan the surface. Just deletes
                everything FAST. This is the default if an unformatted
                harddisk is detected.
  /S            Copies the operating system files to make the disk
                bootable. Needs SYS. The displayed size info describes
                the pre-SYS state!
  /T:tracks     Specifies the number of tracks on a floppy disk.
  /U            Unconditionally formats the disk. The disk cannot be
                UNFORMATed. Causes lowlevel format for floppy and
                surface scan, overwriting all data with "empty" sectors,
                for harddisk. This is the default if an unformatted
                floppy is detected. NOTE: This option may last VERY
                VERY long! Press ESC and wait to exit /U.
  /V:label      Specifies a volume LABEL for the disk, stores date and
                time of it (is not for 160k/320k disks).
  /Y            Do not prompt for a new floppy, just format at once.
                Similar to /AUTOTEST and /BACKUP switches in other
                FORMAT implementations. (Always allowed).
  /Z:longhelp   Gives detailed, technical usage information.
  /Z:mirror     Just save the "MIRROR" data for a later UNFORMAT. This
                will overwrite the very end of the disk with a copy of
                one FAT, root directory and main boot sector. If this
                space is in use, MIRROR will fail (new feature 0.91r).
                To force, you MIGHT use SafeFormat plus UnFormat instead
                - SafeFormat is allowed to overwrite data. It is not
                possible to save mirror data to another location.
  /Z:seriously  Suppresses the confirmation request when you use format
                with a hard disk. Similar to the /AUTOTEST switch in
                other FORMAT implementations.
  /Z:unformat   This will "restore" saved "MIRROR" data (copy it back,
                overwriting your FATs etc. with the backup). Do ONLY use
                this if you have just accidentally formatted a disk. In
                all other situations, UNFORMAT can seriously trash the
                disk contents.
  /?            Shows the help.


  Warning: while format supports FAT32, running under Win9x to create
  FAT32 does not work well.
  Modes for FLOPPY are: Tries to use quick safe format. Use lowlevel
  format only when needed. Quick safe format saves mirror data for
  Modes for HARDDISK are: Tries to use quick safe format. Use quick full
  format only when needed. Quick full format only resets the filesystem.
  If you want to force lowlevel format (floppy) or want to have the
  whole disk surface scanned and all contents wiped (harddisk), use /U.
  FORMAT /Q /U is quick full format (no lowlevel format / scan / wipe!)
  FORMAT /Q is quick save format (save mirror data if possible).
  The mirror data will always overwrite the end of the data area!
  FORMAT autoselects a mode (see above) if you select neither /Q nor /U.

  Supported FAT types are: FAT12, FAT16, FAT32, all with mirror /
  Supported floppy sizes are: 160k, 180k, 320k, 360k and 1200k for 5,25
  inch and 720k and 1440k (2880k never tested so far) for 3,5 inch
  Supported overformats are: 400k, 800k, 1680k (and 3660k) with more
  sectors and 1494k (instead of 1200k) and 1743k (and 3486k) with more
  tracks, too. More tracks will not work on all drives, use at your own
  Warning: older DOS versions can only use overformats with a driver.
  720k in 1440k needs 720k media. Use a 360k drive to format 360k.
  For FAT32 formatting, you can use the /A switch to force 4k alignment.
  FORMAT has the following ERRORLEVEL / EXITCODES:
    0        Okay,
    1        Bad sectors detected (only if /d or /y or
             /z:seriously option active)
    2        Help screen shown or syntax error,
    3        User abort,
    4        Format error,
    5        User did not confirm.
  Errorlevels 1 and 2 are extensions beyond MS FORMAT style.
  If you use the /D flag, errorlevels will be different.
  They will be specific to the particular FORMAT version.

  In 0.91t, for example:
    0        Okay,
    1        Bad sectors detected,
    2        Help displayed or syntax error,
    10..13   Userint error (not confirmed / syntax error)
    20..22   Createfs error (filesystem creation),
    25..29   dDrive I/O error,
    30..31   Recordbc error (existing filesystem analysis),
    35..36   Uformat error (unconditional format),
    38..39   Savefs error (SafeFormat / Mirror)
    40..52   Floppy error,
    55..59   Hdisk error,
    60..62   Main error: unsuitable drive type, e.g. CD-ROM,
   128..255  Critical error (userint: (DOS or BIOS error code) | 128)


  Example 1:
  Making a diskette bootable version 1:
  From an existing bootable HD or CD:
    fdisk      (is not needed!)
    format a:  (Formats the diskette so that files can be written).
    sys a:     The KERNEL (KERNEL.SYS) and COMMAND.COM
               will be copied from your bootable HD or CD to A:; after
               the execution the diskette will be bootable.
  Example 2:
  Making a diskette bootable version 2:
  From an booted diskette (in drive A:):
    fdisk      (is not needed!)
    format b:  (Formats the diskette so that files can be written).
               Depending on if you have two floppy drives or not the
               format command formats at drive B: or asks you to enter
               a new floppy into drive A: and formats from there.
               When this is done, insert the original diskette again,
               then enter:
    sys b:     The KERNEL (KERNEL.SYS) and COMMAND.COM
               will be copied from your bootable diskette A: to B:,
               (same procedure as format b:) after the execution
               the diskette will be bootable.
  Example 3:
  Making a HD bootable:
  From an existing bootable diskette or CD:
    fdisk      (This allows you to create ONE or MORE partitions, see
               FDISK; up to FOUR primary
               partitions can be created. (If you create four primary
               partitions the remaining space of your HD can not be
               used!) Do not forget to reboot!
    fdisk      Set ACTIVE PARTITION (only THIS ONE partition can boot,
               but you can change this by making one of the three other
               primary partitons ACTIVE (there is NO boot manager) with
               fdisk. Do not forget to reboot!
    format c:  Prepares the HD to so that files can be written on it.
    sys c:     The KERNEL (KERNEL.SYS) and COMMAND.COM
               will be copied from your bootable diskette or CD to C:
  Example 4:
  format a: /f:1440   formats a 1,4 MB diskette
  format c: /v:my_hd  formats a harddisk, label: my_hd

See also:

  Copyright © 1998 Jim Hall, updated 2008 and 2022
  by W. Spiegl.

  This file is derived from the FreeDOS Spec Command HOWTO.
  See the file H2Cpying for copying conditions.