Important Notice

The pages on this site contain documentation for very old MS-DOS software, purely for historical purposes. If you're looking for up-to-date documentation, particularly for programming, you should not rely on the information found here, as it will be woefully out of date.

                        ◄Example►                ◄Contents►  ◄Index►  ◄Back►
──────────────────────────────────────────────────────────────────────────────
' This example uses the PEN statement to enable event trapping and the PEN
' function to display current light pen status and position. ON PEN GOSUB
' passes control to the PenReport subroutine when a pen event occurs.
 
' Note: Do not run this example if your mouse driver is enabled.
 
' To try this example:
' 1. Choose New Project from the File menu
' 2. Copy the code example below to the code window
' 3. Press F5 to run the example
 
 CLS                         ' Clear the screen
 COLOR 0, 7                  ' Set black on white
 CLS                         ' Clear the screen
 PEN ON                      ' Enable light pen
 ON PEN GOSUB PenReport
 DO
     LOCATE 23, 12
     PRINT "Press the light pen against the screen to see a report."
     LOCATE 24, 17
     PRINT "  Press the Spacebar to exit the program.     ";
 LOOP UNTIL INKEY$ = " "
 PEN OFF                     ' Disable light pen
 COLOR 7, 0                  ' Set back to black on white
 CLS                         ' Clear the screen
 END
 
PenReport:
     DO
          P = PEN(3)
          LOCATE 10, 27  ' Report light pen status and get X and Y position
          PRINT "A Pen event has occurred."
          LOCATE 24, 17
          PRINT "Press ANY key to exit the Light Pen report.";
          LOCATE 12, 30
          PRINT "Light Pen is ";
          IF P THEN
               PRINT "Down"
               X = PEN(4): Y = PEN(5)
          ELSE
               PRINT "Up  "
               X = 0: Y = 0
          END IF
          LOCATE 14, 22  ' Report the X and Y position
          PRINT "X Position ="; X; "   "
         LOCATE 14, 40
         PRINT "Y Position ="; Y; "   "
     LOOP WHILE INKEY$ = ""
     RETURN