SUBROUTINE RECT

 RECT plots a rectangle defined by the lower left and upper right hand corners. The pen moves UP to lower left hand of the rectangle, plots the rectangle, and leaves the pen DOWN at the lower left corner.

CALL RECT (x1,y1,x2,y2)

x1,y1 (R): lower left hand corner coordinates
x2,y2 (R): upper right hand corner coordinates