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BACKSPACE command

The BACKSPACE command moves  a  magnetic  tape  set  backward  over  a
specified number of files or records.


Format

     @BACKSPACE (DEVICE) dev:  n units

     where:

     dev:      is the name of the tape set or magnetic tape drive that
               you want to move backward.  The colon after the device
               name is optional.

     n         is the number of files or records over which you want
               to backspace.

               Default n - 1

     units     is either FILES or RECORDS.
               Default units - FILES


Restrictions

     BACKSPACE with Open Files

     If you have given a CTRL/C to exit from a program that has opened
     a magnetic tape drive and you then give the BACKSPACE command for
     that tape drive, the system will first ask if you want  to  close
     the  associated  file.   You must do so for BACKSPACE to succeed,
     but you will probably be unable to continue the program from that
     point because the file will now be closed.

     RECORDS Argument Used for Unlabeled Tapes Only

     You cannot give the RECORDS argument  to  the  BACKSPACE  command
     when  using a labeled tape, because read and write operations for
     labeled tapes always move the tape to the  beginning  of  a  file
     first.


Related Commands

     SKIP

          For moving a magnetic tape set forward.

     REWIND

          For backspacing a tape volume or tape  set  to  its  logical
          beginning (the beginning of the first file).

     UNLOAD

          For completely rewinding a magnetic  tape  onto  the  source
          reel.


Examples

     1.  Backspace your magnetic tape one file.

         @BACKSPACE MTA0: 1 FILE