Mouse Computing

Operating a mechanical mouse (Fig. 2).
1: Moving the mouse turns the ball.
2: X and Y rollers grip the ball and transfer movement.
3: Optical encoding disks include light holes.
4: Infrared LEDs shine through the disks.
5: Sensors gather light pulses to convert to X and Y velocities.

A  mouse is a handheld pointing device for computers, being a small object fitted with one
or more buttons and shaped to sit naturally under the hand. The underside of the mouse houses a
device that detects the mouse's motion relative to the flat surface on which it moves. The mouse's
2D motion is typically translated into the motion of a pointer on the display.
It is called a mouse primarily because the cord on early models resembled the rodent's tail,
and also because the motion of the pointer on the screen can be mouse-like (Fig. 2).