BORDER ON|OFF [number]

* Switches the border of the window on or off. If the border is off
  there will fit some more characters in a line; this can be useful
  when viewing texts with  MORE .
* If you run OS1.3-, you should do a  CLS  or "echo ^L" after
  using BORDER OFF.
* If you specify a number after ON or OFF, the window is resized as
  large as possible. The number means the wanted distance of the
  window top to the screen top in pixels. By specifying a negative
  value the window will just not hide the screens menu bar.

eg.     border off
        border on 0         {fills full screen}
        border off -1       {does not hide the menu bar}
        border on 10;cls    {with OS1.3-}