You can invoke TECO with the traditional TECO commands, TECO, MAKE,
  and MUNG.

  Formats

  TECO file-spec                    to edit an existing file
  TECO out-file-spec=in-file-spec   to edit from one file to another
  MAKE file-spec                    to create a new file
  MUNG cmd-file-spec                to execute a TECO command file
  MUNG cmd-file-spec text-arg       as above, but passes a text argument
                                    in the text buffer

  As these are not built-in DCL commands, you must define them in your
  LOGIN.COM file. You may define these as foreign commands, as follows:

           TECO == "$SYS$SYSTEM:TECO32 TECO "
           MAKE == "$SYS$SYSTEM:TECO32 MAKE "
           MUNG == "$SYS$SYSTEM:TECO32 MUNG "

  Alternately, you may define the commands as synonyms for the equivalent
  DCL EDIT/TECO commands, as follows:

           TECO == "EDIT/TECO"
           MAKE == "EDIT/TECO/CREATE"
           MUNG == "EDIT/TECO/EXECUTE"

  Note that interpretation of qualifiers depends on how you have
  defined the commands. The qualifiers documented in this section apply
  to the foreign command definition. For details on the EDIT/TECO
  command, see the description of the EDIT command in this help library
  or EDIT/TECO in the main DCL help library, HELPLIB.HLB.