Main Page | See live article | Alphabetical index A trackball is a pointing device consisting of a ball housed in a socket containing sensors to detect rotation of the ball about two axes - like an upside-down mouse. The user rolls the ball with his thumb or the palm of his hand to move a cursor. Tracker balls are common on CAD workstations for ease of use and on modern portable computers, where there may be no desk space on which to use a mouse. Some clip onto the side of the keyboard and have integral buttons which have the same function as mouse buttons. This article (or an earlier version of it) contains material from FOLDOC, used with permission. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.