VT100: EXT + F or Ctrl/F        VT200: EXT + F11
    DEFINE_KEY Function: SET_PRINTFILE

    Lets you change the name of the file or device that receives
    output each time you invoke the PRINT function. After you invoke
    SET FIL, you are prompted for the name of a new output device,
    emulating the remote host's IDENT function.

    Note that if you specify the same name that is already in use,
    subsequent PRINT operations direct output to a new version of the
    same file.