Abstract: A cursor control and command input device for use with cathode ray tube displays is disclosed. The apparatus includes two cursor positioning spheres that are rotatably mounted within the reach of a user's thumbs without the user having to move his fingers from their current home position of the input device. In addition, devices for sensing the rotation of the spheres and generating output signals based upon such rotation is also provided. Command keys are also provided which are used in conjuction with the cursor positioning spheres to select various options or turn on and off the cursor positioning spheres and operated by the thumbs of the user without requiring that the user change the location of his fingers.