tcb(1)                                                     tcb(1)



     NAME
          tcb - block data to 8K for tc output

     SYNOPSIS
          command-line | tcb >/dev/rmt/tcx

     DESCRIPTION
          tcb reads standard input and writes standard output in a
          blocking format suitable for the Apple SC 40 Tape Backup.
          The output of tcb is always blocked at 8K to satisfy the
          blocking requirements of the tape cartridge drive.  The last
          output block is zero-filled as necessary.

          If the output of tcb is sent through another pipe before be-
          ing directed to the tape cartridge drive, the tape-specific
          blocking of data tcb will be lost.

          The following example illustrates how to create a tar ar-
          chive on cartridge tape.  Substituting the SCSI ID of your
          tape cartridge drive for x, enter

             tar cvf - . | tcb >/dev/rmt/tcx

          To create an archive that will be larger than one tape, use
          the size (B) flag option for tar.  This flag option allows
          you to specify the capacity of the tape cartridge in terms
          of 512-byte blocks.  This may be computed using a conversion
          factor of 2048 blocks per MB.

          To read from an archive written with tar and tcb, use dd(1)
          and specify an 8K blocking size.  Better performance results
          from the use of a larger input buffer size, as long as it is
          a multiple of 8K:

             dd if=/dev/rmt/tcx ibs=20x8K |tar xvf -



     SEE ALSO
          dd(1), tar(1), tc(7).















     April, 1990                                                     1