TOPS-20 Commands Reference Manual


Writes an end-of-file mark on the specified magnetic tape. Use this command for unlabeled tapes only.


@EOF (DEVICE) dev:


dev: is the name of the magnetic tape drive on which you want to write an end-of-file mark. The colon after the device name is optional.


EOF Seldom Needed

Because tape-writing programs and commands automatically write end-of-file marks in the appropriate places, you do not ordinarily need the EOF command. But it can be useful if such a program is interrupted (by your CTRL/C or by a system failure and restart) and you want to preserve the information already written. Also, you can shorten files on an existing tape by giving an EOF command at the desired point.


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

Related Commands

other TOPS-20 commands for controlling magnetic tape drives


  1. Put an end-of-file mark (EOF) on your magnetic tape.
    @EOF MTA0: