diff --git a/PS2Mouse.cpp b/PS2Mouse.cpp
index 9e1e693..cf55ef8 100644
--- a/PS2Mouse.cpp
+++ b/PS2Mouse.cpp
@@ -213,6 +213,16 @@ int PS2Mouse::read_movement_y(int status) {
   return y;
 }
 
+int PS2IMouse::read_movement_z() {
+  int z = read();
+  if (bitRead(z, 5)) {
+    for(int i = 4; i < 16; ++i) {
+      z |= (1<<i);
+    }
+  }
+  return z;
+}
+
 void PS2Mouse::pull_low(int pin) {
  	pinMode(pin, OUTPUT);
   digitalWrite(pin, LOW);  
@@ -222,3 +232,39 @@ void PS2Mouse::pull_high(int pin) {
   pinMode(pin, INPUT);
   digitalWrite(pin, HIGH);
 }
+
+PS2IMouse::PS2IMouse(int clock_pin, int data_pin, int mode): PS2Mouse(clock_pin, data_pin, mode)
+{
+}
+
+void PS2IMouse::initialize() {
+  PS2Mouse::initialize();
+  msMode();
+}
+
+void PS2IMouse::msMode() {
+  write(0xf3); // Tell the mouse we are going to set the sample rate.
+  read_byte(); // Read Ack Byte
+  write(200); // Send Set Sample Rate
+  read_byte(); // Read ack byte
+  write(0xf3); // Tell the mouse we are going to set the sample rate.
+  read_byte(); // Read Ack Byte
+  write(100); // Send Set Sample Rate
+  read_byte(); // Read ack byte
+  write(0xf3); // Tell the mouse we are going to set the sample rate.
+  read_byte(); // Read Ack Byte
+  write(80); // Send Set Sample Rate
+  read_byte(); // Read ack byte
+  write(0xf2); // Get device ID.
+  read_byte(); // Read should be 03
+}
+
+int * PS2IMouse::report(int data[]) {
+  write(0xeb); // Send Read Data
+  read_byte(); // Read Ack Byte
+  data[0] = read(); // Status bit
+  data[1] = read_movement_x(data[0]); // X Movement Packet
+  data[2] = read_movement_y(data[0]); // Y Movement Packet
+  data[3] = read_movement_z(); // Z Movement Packet
+  return data;
+}
diff --git a/PS2Mouse.h b/PS2Mouse.h
index 6dc2ee7..a4df43f 100644
--- a/PS2Mouse.h
+++ b/PS2Mouse.h
@@ -13,13 +13,14 @@ class PS2Mouse
     int _initialized;
     int _enabled;
     int _disabled;
-    int read_byte();
     int read_bit();
-    int read_movement_x(int);
-    int read_movement_y(int);
     void pull_high(int);
     void pull_low(int);
     void set_mode(int);
+  protected:
+    int read_byte();
+    int read_movement_x(int);
+    int read_movement_y(int);
   public:
     PS2Mouse(int, int, int mode = REMOTE);
     void initialize();
@@ -38,5 +39,16 @@ class PS2Mouse
     void set_sample_rate(int);
 };
 
+class PS2IMouse : public PS2Mouse
+{
+  private:
+    void msMode();
+    int read_movement_z();
+  public:
+    PS2IMouse(int, int, int mode = REMOTE);
+    void initialize();
+    int* report(int data[]);
+};
+
 #endif
 
diff --git a/examples/Wheel/Wheel.ino b/examples/Wheel/Wheel.ino
new file mode 100644
index 0000000..fa1bc4b
--- /dev/null
+++ b/examples/Wheel/Wheel.ino
@@ -0,0 +1,40 @@
+/**
+ * Reads X/Y values from a PS/2 mouse connected to an Arduino
+ * using the PS2Mouse library available from
+ *   http://github.com/kristopher/PS2-Mouse-Arduino/
+ * Original by Kristopher Chambers <kristopher.chambers@gmail.com>
+ * Updated by Jonathan Oxer <jon@oxer.com.au>
+ */
+
+#include <PS2Mouse.h>
+#define MOUSE_DATA 4
+#define MOUSE_CLOCK 2
+
+PS2IMouse mouse(MOUSE_CLOCK, MOUSE_DATA, REMOTE);
+
+/**
+ * Setup
+ */
+void setup()
+{
+  Serial.begin(38400);
+  mouse.initialize();
+}
+
+/**
+ * Main program loop
+ */
+void loop()
+{
+  int data[4];
+  mouse.report(data);
+  Serial.print(data[0]); // Status Byte
+  Serial.print(":");
+  Serial.print(data[1]); // X Movement Data
+  Serial.print(",");
+  Serial.print(data[2]); // Y Movement Data
+  Serial.print(",");
+  Serial.print(data[3]); // Z Movement Data (wheel)
+  Serial.println();
+  delay(20);
+}