Chapter 18: Keyboards, Mice, and Pointing Devices^473
Joysticks
A joystick is a type of pointing device that is used primarily with game software on a
PC. A joystick consists of a handle that is connected to a yoke inside its base. The yoke is
set on a pivoting mechanism that allows the joystick to move in any direction from a
center point. Sensors are attached to the yoke that detect the movement of the handle and
yokeonanx-yaxisandsenddatasignalstotheadaptercardtowhichthejoystickisattached.
Most joysticks attach to a game port located on a game, video, or sound card, but many
new models also support a USB connection as well. A software device driver then interprets
the data signals sent from the joystick and transfers the actions onto the screen.
Some joysticks areforce-feedbackdevices that simulate pressure and forces on the joy-
sticktomakethegamemorerealistic,likethe3DjoystickshowninFigure18-28.Joysticks
with 3D capabilities include anr-axis that simulates rotational movement in addition to
moving u pand down and from side to side. On force-feedback units, the game software
sends signals back to the joystick that instruct it when to apply force or resist or remove
resistance from the motion of the handle. On the handle of the joystick are usually a number
of triggers and button that are programmed by the game software to shoot, brake, turn,
accelerate, jump, or whatever action the game allows. Most game software includes
routinestoallowtheusertoreprogramthesettingsforthejoystickstriggersandbuttons.
Figure 18-27. A glidepoint mouse in a notebook computer keyboard