diff --git a/stella/src/emucore/TrackBall.cxx b/stella/src/emucore/TrackBall.cxx
index e79a0d31c..cba37fde2 100644
--- a/stella/src/emucore/TrackBall.cxx
+++ b/stella/src/emucore/TrackBall.cxx
@@ -13,7 +13,7 @@
 // See the file "license" for information on usage and redistribution of
 // this file, and for a DISCLAIMER OF ALL WARRANTIES.
 //
-// $Id: TrackBall.cxx,v 1.1 2008-05-12 22:40:25 stephena Exp $
+// $Id: TrackBall.cxx,v 1.2 2008-05-19 03:15:12 stephena Exp $
 //============================================================================
 
 #include "Event.hxx"
@@ -154,6 +154,13 @@ void TrackBall::update()
   myDigitalPinState[Six] = (myEvent.get(Event::MouseButtonValue) == 0);
 }
 
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+void TrackBall::systemCyclesReset()
+{
+  myCyclesWhenSWCHARead -= mySystem.cycles();
+}
+
+
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 const uInt32 TrackBall::ourTrakBallTableTB_H[2][2] = {
   { 0x40, 0x00 }, { 0xc0, 0x80 }
diff --git a/stella/src/emucore/TrackBall.hxx b/stella/src/emucore/TrackBall.hxx
index e4a9502ed..1eb4f212a 100644
--- a/stella/src/emucore/TrackBall.hxx
+++ b/stella/src/emucore/TrackBall.hxx
@@ -13,7 +13,7 @@
 // See the file "license" for information on usage and redistribution of
 // this file, and for a DISCLAIMER OF ALL WARRANTIES.
 //
-// $Id: TrackBall.hxx,v 1.1 2008-05-12 22:40:25 stephena Exp $
+// $Id: TrackBall.hxx,v 1.2 2008-05-19 03:15:12 stephena Exp $
 //============================================================================
 
 #ifndef TRACKBALL_HXX
@@ -35,7 +35,7 @@
     AmigaMouse:  Amiga Mouse
 
   @author  Stephen Anthony & z26 team
-  @version $Id: TrackBall.hxx,v 1.1 2008-05-12 22:40:25 stephena Exp $
+  @version $Id: TrackBall.hxx,v 1.2 2008-05-19 03:15:12 stephena Exp $
 */
 class TrackBall : public Controller
 {
@@ -70,6 +70,13 @@ class TrackBall : public Controller
     */
     virtual void update();
 
+    /**
+      Notification method invoked by the system right before the
+      system resets its cycle counter to zero.  It may be necessary 
+      to override this method for devices that remember cycle counts.
+    */
+    virtual void systemCyclesReset();
+
   private:
     // Counter to iterate through the gray codes
     int myHCounter, myVCounter;