Returns the status of the light pen.
 
PEN(n%)
 
    - n%    Specifies the information to be returned about light pen status:
 
            n%    Returns
            --    ---------------------------------------------------------
            0     Whether pen was used since last call (-1 if yes, 0 if no)
            1     The x screen coordinate of the last pen press
            2     The y screen coordinate of the last pen press
            3     The current pen switch status (-1 if down, 0 if up)
            4     The x screen coordinate where the pen last left the screen
            5     The y screen coordinate where the pen last left the screen
            6     The character row of the last pen press
            7     The character column of the last pen press
            8     The character row where the pen last left the screen
            9     The character column where the pen last left the screen
 
Example:
    DO
      P = PEN(3)
      LOCATE 1, 1: PRINT "Pen is ";
      IF P THEN PRINT "down" ELSE PRINT "up  "
      PRINT "X ="; PEN(4), " Y ="; PEN(5); "  "
    LOOP
 
See Also    <PEN, ON PEN STATEMENTS>    <SCREEN>    <SCREEN MODES>