diff --git a/src/emucore/Driving.cxx b/src/emucore/Driving.cxx
index 1cab7b75a..2fb5a4840 100644
--- a/src/emucore/Driving.cxx
+++ b/src/emucore/Driving.cxx
@@ -114,6 +114,7 @@ void Driving::updateControllerAxes()
 {
   // Digital events (from keyboard or joystick hats & buttons)
   const int d_axis = myEvent.get(myXAxisValue);
+  uInt32 oldCounterHires = myCounterHires;
 
   if(myEvent.get(myCCWEvent) != 0 && myLastCCWEvent == 0)
     myCounterHires = ((myGrayIndex + 4) * 256.0F) / SENSITIVITY - 1; // set to end of previous counter interval
@@ -136,16 +137,17 @@ void Driving::updateControllerAxes()
        range as digital inputs.
     */
     myCounterHires += (a_axis/512) + (a_axis >= 0);
-    cerr << "! ";
   }
 
-  // Only consider the lower-most bits (corresponding to pins 1 & 2)
-  myGrayIndex = static_cast<Int32>((myCounterHires / 256.0F) * SENSITIVITY) & 0b11;
+  if(oldCounterHires != myCounterHires)
+    // Only consider the lower-most bits (corresponding to pins 1 & 2)
+    myGrayIndex = static_cast<Int32>((myCounterHires / 256.0F) * SENSITIVITY) & 0b11;
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void Driving::updateMouseAxes()
 {
+  Int32 oldCounter = myCounter;
   static constexpr int MJ_Threshold = 2;
 
   // Mouse motion and button events
@@ -178,6 +180,8 @@ void Driving::updateMouseAxes()
         ++myCounter;
     }
   }
+  if(myCounter != oldCounter)
+    myGrayIndex = (myCounter >> 2) & 0b11;
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@@ -206,6 +210,7 @@ void Driving::updateStelladaptorAxes()
     // simulated gray codes generated by PC keyboard or PC joystick
     // Must be rounded into the middle of the myCounter interval!
     myCounter = (myGrayIndex + 0.5F) * 4.0F / SENSITIVITY;
+    myCounterHires = myCounter * 256.0F / 4.0F;
   }
 }