tcb(1)                                                     tcb(1)



NAME
     tcb - blocks data to 8K for direct input to /dev/rmt/tcx

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

ARGUMENTS
     command-line
          Specifies the command line which generates the output
          channeled to the tcb command.

     x    Specifies the Small Computer System Interface (SCSI) ID
          of the tape cartridge drive.

DESCRIPTION
     tcb reads standard input and writes standard output in a
     blocking format suitable for the Apple Tape Backup 40SC.
     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 being directed to
     the tape cartridge drive, the tape-specific blocking of tcb
     data is lost.

     To create an archive that is larger than one tape, specify
     tar along with the -B option and a size argument.  This
     option allows you to specify the capacity of the tape
     cartridge in terms of 512-byte blocks.  You compute the
     capacity by 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 using a larger input buffer size, as long as the buffer
     size is a multiple of 8K:

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


EXAMPLES
     The following example illustrates how to create a tar
     archive on cartridge tape.  The SCSI ID of your tape
     cartridge drive is 2 in this example.  Type:

        tar cvf - . | tcb >/dev/rmt/tc2


SEE ALSO
     dd(1), tar(1)

     tc(7) in A/UX Programmer's Reference





January 1992                                                    1