A pointing device is an external tool that is used to move objects around and also to select options from menus. The pointing device is an element of the graphical user interface. It manipulates on screen objects to issue commands. Examples of pointing devices include the mouse, trackball, light pen, pen for graphic tablet, joystick, touch screen, wand, head mounted display, virtual reality glasses, and 3-D mouse.
The concept of the pointing device was developed in 1970 by Douglas Engelbart as another way to input information into the computer other than through the keyboard. This input device has become popular and with the growth of the graphical user interface it has become one of the most necessary and important tools of the computer.
The mouse is included in almost every computer that is sold today. Besides becoming an important input tool, it has provided access to the computer for many individuals with disabilities that might not otherwise have the opportunity to use the computer.
The pointing device also lets you double click on an icon to start a program application; and in the WINDOWS 95 operating system you can use the mouse to drag a file or document to the Recycling Bin to delete a file.
The computer mouse moves by way of a roller and ball system. When you move the mouse across the desktop, the ball underneath rolls. This ball corresponds to the position of what is called a pointer on the screen. The pointer is usually shaped like an arrow, though some people like to change their pointer to look like objects. (One person in our group has changed his pointer to an ink pen icon.) When you move the pointer around it is called mousing. The speed of the mouse can be managed by your computer operating system software, or a commercial application program for your mouse. You can drag objects on the screen by clicking on the object, holding down on the mouse button, and rolling the mouse across the desktop until you get the object to a new location. When you reach the spot that you want, let go of the mouse button.
Most mice come with two buttons. You use the left button on the mouse to do most selecting of objects. The right button can be used for some menu actions. This is especially true when using browser software to examine and manipulate pictures and graphics on the Internet. There is a three button mouse and the middle button can be programmed for specific application software, but usually the two button mouse is used the most. If you are left handed, you can change to a left-handed mouse option in your software so that you can use your mouse in your left hand.
Pen- The pen lets you draw on what is called a digitizing tablet that mirrors the surface area of the computer screen. The pen can be used as a standard mouse (without wires connected to it) or also as a free flowing drawing device. The pen is useful for drawing since drawing graphics with a mouse tends to be somewhat difficult.
Mouse - The mouse is a hand held device that lets you point to and selected items on your screen. In a PC mouse there are mostly 2-3 buttons and on a Mac there is one. A ball under the mouse senses movement. To ensure smooth motion your should remove the ball and clean it regularly.
Cordless Mouse - The cordless mouse is a lot better than a normal mouse thus by reducing the clutter of the work space needed to move the mouse around. This mouse runs on a battery. When you move the mouse it sends an infrared beam to a sensor which interprets it causing it to move.
Trackball - The trackball is an upside-down mouse that remains stationary on your desk. It is the same principle as the mouse except that the rollers are reversed and the ball is on top. This ball does not need as much attention as the normal mouse because the only thing that touches it is your hand as the normal mouse touches a surface.
Touchpad - The touchpad has sensors that sense your touch. When they sense your touch they send a signal to the computer to move the mouse pointer to that location on the screen.
Joystick- The joystick allows the user to move quickly in computer games.
Light pen- The light pen system allows the user to touch the computer screen with a lighted pen to activate commands and make selections.
Touch Screen- The touch screen lets the user touch the area to be activated by using the finger or hand.
Head Mounted Virtual Reality Displays, Wands, Special Trackballs, Data Gloves, and Special 3-D Flying Mice that can go in six different directions- These devices are currently the newest pointing devices.
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