Specifies the debugger interface (DECwindows Motif or command)
    or the display device (if you are displaying the interface on a
    workstation).

    By default, DBG$DECW$DISPLAY is either undefined or has the same
    definition as the application-wide logical name DECW$DISPLAY.

    The DECwindows Motif interface is the default on workstations.
    To display the command interface instead of the DECwindows Motif
    interface, enter the following definition before starting the
    debugger:

    $ DEFINE DBG$DECW$DISPLAY " "

    For complete information about the DECwindows Motif interface,
    see the debugger's DECwindows Motif documentation.