TOPS-20 Commands Reference Manual


Rewinds a magnetic tape until it is returned completely to the source reel, and puts the associated tape drive offline. Use UNLOAD only for tapes mounted on drives having device names of the form MTAn:.




dev: is the name of the magnetic tape drive that you want to unload.


UNLOAD 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 gave the UNLOAD command for that tape drive, the system will first ask if you want to close the associated file. You must do so for UNLOAD to succeed, but you will probably be unable to continue the program from that point because the file will now be closed.

UNLOAD Not for MOUNTed Drives

Use the UNLOAD command for tape drives obtained with the ASSIGN command. Use DISMOUNT for a tape drive obtained with MOUNT.


Cannot Access Tape Again

The UNLOAD command makes it impossible to access your tape again unless it is reloaded by the operator.

Related Commands

ASSIGN for assigning a tape drive to your job
DISMOUNT for unloading tapes mounted on devices of the form MTn:
REWIND for rewinding a magnetic tape volume or tape set to its load point (logical beginning)


  1. Unload your magnetic tape from drive MTA0:.