360's in-game menu (accessed by pressing the "Xbox" button), or the PlayStation 3's mid-game XMB. It may be accessed under most circumstances during Wii operation, which pauses the on-screen action. Otherwise, a "home" symbol with a no symbol on it appears onscreen. It is also inaccessible during Nintendo GameCube play, as the Wii Remote cannot control Nintendo GameCube software. Features Sensing The Wii Remote has the ability to sense acceleration along three axes through the use of Analog Devices MEMS-based three-dimensional accelerometers. The Wii Remote also has a PixArt optical sensor that allows it to determine where it is pointing. Unlike a light gun that senses light from a television screen, the Wii Remote senses light from the console's Sensor Bar (RVL-014), which allows consistent usage not influenced by the screen used. The Sensor Bar is about long and has ten infrared LEDs, five at each end of the bar. The LEDs furthest from the center are pointed slightly outwards, the LEDs closest to the center are pointed slightly inwards, while the rest are pointed straight forward. The Sensor Bar's cable is in length. The bar may be placed above or below the television, centered horizontally, in line with the front of the television or the front of the surface the television is placed on. The Remote should be pointed approximately towards the Sensor Bar; precise pointing is not necessary so long as it is within the limited viewing angle of the Wii Remote. Use of the Sensor Bar allows the Wii Remote to be used as an accurate pointing device up to 5 meters (approx. 16 ft) away from the bar. The Wii Remote's image sensor is used to locate the Sensor Bar's points of light in the Wii Remote's field of view. The light emitted from each end of the Sensor Bar is focused onto the image sensor which sees the light as two bright dots separated by a distance "mi" on the image sensor. The second distance "m" between the two clusters of light emitters in the Sensor Bar is a fixed distance. From these two distances m and mi, the Wii CPU calculates the distance between the Wii Remote and the Sensor Bar using triangulation. Rotation of the Wii Remote with respect to the ground can also be calculated from the relative angle of the two dots of light on the image sensor. Games can be