diskformat(1M)                                     diskformat(1M)



     NAME
          diskformat - format a disk through a driver-dependent format
          operation

     SYNOPSIS
          diskformat [-dens n] [-head 0] floppy-device
          diskformat [-cyl s[-[e]]] [-size 532] hard-disk-device

     DESCRIPTION
          diskformat initializes a hard or floppy disk by passing any
          specified parameters through the corresponding generic dev-
          ice interface, such as fd(7) or gd(7).  This means that the
          parameters for diskformat can be interpreted differently for
          different classes of devices.  For example, one form of this
          command can be used to format hard disks, and in that case
          the head option is ignored.  However, the head argument is
          honored whenever it is passed through the fd (floppy) inter-
          face.

          For an Apple(Reg.) Hard Disk SC, the preferred method is to
          use Apple HD SC Setup to format and partition disks.  That
          way, Apple HD SC Setup, as well as other Macintosh(Reg.)
          utilities, are able to read the partition map and discover
          the whereabouts of any Macintosh file systems.

          Before diskformat actually formats a disk, it issues the
          following message

             About to format device. Type return to continue:

          and waits for you to confirm the operation.  This gives you
          a final opportunity to cancel the format operation, because
          it overwrites any previous data and programs on the media
          referenced as floppy-device or hard-disk-device.  Note that
          any response at all, other than the interrupt or suspend
          character, causes diskformat to continue its operation.

          You must specify a raw floppy-device or hard-disk-device for
          this command, as described in fd(7) and gd(7).

          Without any options, the floppy disk is formatted at the
          highest recording density supported by the media and the
          drive, as long as floppy-device references one of the fol-
          lowing autodensity device files:

             /dev/rfloppy[01]
             /dev/rfd/d[01]

          However, if the diskformat command is specified without any
          options and the floppy media is referenced through a device
          file of fixed density, the media is formatted at the expect-
          ed density, if at all possible.  See fd(7) for a list of the



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     diskformat(1M)                                     diskformat(1M)



          device files with fixed densities.

     FLAG OPTIONS
          The following flag options may be used:


          -cyl s[-[e]] Format cylinders starting from s and ending
                       with e.  A specification such as s- means
                       starting from s and proceeding to the end of
                       the media.  Note that while start and end
                       cylinders can be specified for any device, they
                       are only honored if the device driver supports
                       them. See Section 7 for details about particu-
                       lar device drivers, such as fd(7).

          -dens n      Indicates formatting density for floppy disks
                       only.  A value of 400 specifies 400K single-
                       sided, 720 specifies 720K, 800 specifies 800K
                       double-sided, and 1440 specifies 1440K.

          -head 0      Format a floppy disk for single-sided use
                       (400K).  This option is available as well as
                       the 400 argument for -dens so that drives
                       referenced as fixed density can be forced to
                       honor the command without reporting errors.

          -size 532    Format the hard disk at 532 bytes per physical
                       disk block for compatibility with some early
                       Macintosh hard disk drives.  Logical blocks
                       remain 512 bytes per block. A/UX(Reg.) simply
                       ignores the extra tag bytes at the beginning of
                       each physcial block.

     FILES
          /bin/diskformat

     SEE ALSO
          fd(7), gd(7).

     NOTES
          Before floppy disks can be used with commands such as tar or
          cpio, they must be formatted using diskformat or the
          Macintosh Operating System.

          Writing to a floppy disk previously formatted under the
          Macintosh  Operating System, using utilities such as tar and
          cpio, destroys any previously recorded Macintosh data and
          programs.

          Before a diskformat operation is started, the device is ac-
          cessed in exclusive-use mode. This prevents anyone from for-
          matting the media in a drive already being used, or prevents



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     diskformat(1M)                                     diskformat(1M)



          anyone from using the device while it is formatting media.

          The default formatting density chosen in the absence of the
          dens and head options is determined by the floppy device
          driver based on the floppy-device device file specified, the
          type of floppy drive, and the media inserted.  See fd(7) for
          details.
















































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