Defines the logical coordinates for the current viewport.
WINDOW [ [SCREEN ] (x1,y1)-(x2,y2)]
The keyword SCREEN inverts the screen’s coordinate system such that y values increase in value from the top to the bottom of the screen.
The coordinates x1, y1 and x2, y2 specify the logical coordinates of the viewport.
SCREEN 1
WINDOW (0, 0)-(50, 50)
LINE (10, 10)-(40, 40), 2, B