Pointing Devices

An input device is used to move the pointer (cursor) on screen. The major pointing device is the mouse for the desktop computer and the touchpad for a laptop. Pointing sticks are available on some laptops, and a small number of users prefer trackballs over the mouse.

In the beginning, there was no need to point because computers used crude interfaces like teletype machines or punch cards for data entry. The early text terminals did nothing more than emulate a teletype (using the screen to replace paper), so it was many years (well into the 1960s and early 1970s) before arrow keys were found on most terminals. Full screen editors were the first things to take real advantage of the cursor keys, and they offered humans the first way to point.

It is amazing how simple and effective a pointing device is, and it is also amazing how long it took pointing devices to become a part of everyday life. Given that people naturally point at things -- usually before they speak -- it is surprising that it took so long for a good pointing device to develop. Although originally conceived in the 1960s, a couple of decades passed before mice became conventional.

The most common pointing device by far is the mouse; other kinds include trackball, touchpad, pointing stick, light pen, joystick, head pointer, eye tracking devices, various kinds of digitizing tablets which use a stylus, and even a special "data glove" that translates the user's movements to computer gestures.

The pointing device moves by way of a roller and ball system. When you move the device across the desktop, the ball embedded in the mouse 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. When you move the pointer around, it is called ‘mousing’. The speed of the device can be managed by your computer operating system software, or a commercial application program for your mouse.

These devices are currently the newest pointing devices:
-Head Mounted Virtual Reality Displays
-Wands, Special Trackballs
-Data Gloves
-Special 3-D Flying Mice (that can go in six different directions- these devices are currently the newest pointing devices.)

Computer Services recommends individuals choose a pointing device according to their needs and preferences. A typical mouse may cause physical discomfort for some users. Hand, wrist, and arm pain may result from the excessive use of your mouse. There is a large variety of alternative ergonomic pointing devices on the market.

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 cumbersome.
Mouse - The mouse is a hand held device that lets you point to and select the items on your screen. In a PC mouse, one will commonly find 2-3 buttons where as on a Mac, there is one. A ball under the mouse senses movements. To ensure smooth motion, you should remove the ball and clean it regularly.
Cordless Mouse - The cordless mouse is a lot better than a normal mouse since it reduces the clutter of the work space needed to move the mouse around. This mouse runs on battery. When you move the mouse it sends an infrared beam to a sensor which interprets the movement and executes 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 require as much maintenance 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.
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.

An optical mouse, as opposed to a conventional mouse, does not include any moving wheels and therefore, will not get dirty or clog up over time. Instead, there is only an optical sensor reading the movement of the mouse. An optical mouse is recommended over a conventional mouse. Ideally, purchase one with three buttons and a wheel control. The wheel is very useful for scrolling up and down through the pages of the documents without dragging the cursor all the way to the right hand side of the page. Some pointing devices are wireless, however, one should stay away from infra-red devices. Radio-controlled are generally preferred over the infra-red devices, since they offer a much better signal reliability. For connecting your pointing devices to a PC, the most convenient way may be to purchase pointing devices with a PS/2 connector. All ATX motherboards come with a couple dedicated PS/2 connections - one for a mouse and one for a keyboard. Why not use them? If you are an advanced user, purchase a USB pointing devices instead.