/sys$common/syshlp/helplib.hlb EDIT, /TPU, /INTERFACE  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  /INTERFACE[={CHARACTER_CELL (default) | DECWINDOWS |MOTIF}]

  Same as /DISPLAY---determines the interface or screen display you
  want.  For example, the following command invokes DECTPU with the
  DECwindows Motif interface:

     $ EDIT/TPU /INTERFACE=DECWINDOWS

  Then, if DECwindows Motif is available, DECTPU displays the editing
  session in a separate window on your workstation screen and enables
  DECwindows features---for example, the EVE screen layout includes a
  menu bar and scroll bars, and you can use M1 to move the cursor and
  select text.  If DECwindows Motif is not available, DECTPU works as
  if on a character-cell terminal.  For information about using EVE on
  DECwindows, use the online help in EVE and read the topic called
  DECwindows Differences.