Peripherals are hardware like the Mouse are attached to a computer. This hardware is external to the main case that houses the CPU, Hard drives, and internal components. These devices allow smooth interactions between the computer and its users.
The mouse is an input device for moving a pointer symbol, called a “cursor” across the screen by dragging the physical mouse around a smooth surface. It has at least two buttons, for “left-clicking” ( left button) and “right-clicking” (right button). The most common layout of the mice have three buttons, left, right and a scroll wheel buttons. A mouse translates the user’s hand motion into electrical signals that the PC uses to track a pointer across the monitor’s display. The optomechanical process converts movements of the mouse into light pulses.
The ball, rollers, and disk move mechanically, and the LED and sensor convert light pulses optically. A mouse may have two sets of LEDs and sensors on each optical encoding disk. One on the left side of the disk and the other on the right. Having two LED and sensor sets allow the processor to detect the disk’s rotation direction. The optical mouse eliminates the mouse ball, replacing it with optical sensors that track the mouse movement against the background of the mouse-pad or whichever flat surface it’s on.
There are two other major differences in mice, which are Optical/Laser mice, and Ball mice. The laser measuring the distance it crosses when moved, and the ball measuring how it rotates. Thus sending signal to where the cursor is. The laser is generally more accurate and less of a hassle to use on most surfaces, but the ball mouse is cheaper.
- One button mouse: The Apple mighty mouse uses a single button. This button works by pushing on the front of the mouse or pushing the entire mouse down. It has a simpler interface, and attractive, but difficult to use, with tradition “right-click” needs being changed to pressing a “control” or “ctrl” key on the keyboard while pressing the main button. This type works with Macintosh OS, such as Mac OS X.
- Two-button mice: They are common in older computers, with a button on the left, and right, usually for the index and middle finger .i.e. they have “left click” and “right-click” buttons. While less useful than a three button mouse, they are, when teamed with a standard keyboard, capable of performing almost all computer tasks.
- Three button mice: These are the most common layout. There is a third button added to the “left-click” and “right-click” buttons; the “middle”/”center” click button is a clickable scroll wheel. This design allows the user to scroll through documents, make selections, and do other tasks by moving a finger, rather than pressing an arrow key or “Page up/Page down” key on a keyboard. The center button creates a “middle click” button, which works in some programs to perform a simple function, such as the Firefox web browser, which uses the middle click to open a link in a new tab.
- Four (or more) button mice: Usually seen only on gaming and multimedia specialization mice, extra buttons generally do not serve any native purpose, and rather users assign a function to perform by the user. For example, a user who uses the mouse to play games might assign the extra buttons to switch between modes.
Other Pointing Devices
- Touchpads: This is a fixed-place pointing device embedded on notebook computers keyboard. A touchpad is a small, flat square or rectangular surface on which you slide(touch) your finger to move the cursor on the display. They function as the mouse to the PC. A touchpad provides the same actions as a mouse. It works on the principle of coupling capacitance that uses a two-layer grid of electrodes to hold an electrical charge. You can connect an external touchpad to a PC via its PS/2 port. The touchpad comes with left and right-clicks buttons.
- Joysticks: A joystick is a type of pointing device used primarily with game software on a PC. Joysticks come in various forms, shapes, and configurations based on the choice of the manufacturer. Most joysticks attach to a game port or a USB connection. A software device driver interprets the data signals sent from the joystick and transfers the actions to the screen. Some joysticks are force-feedback devices that simulate pressure and forces on the joystick to make the game more realistic. Joysticks with 3D capabilities include an r-axis that simulates rotational movement in addition to moving up and down and from side to side. The game software has a number of triggers and button. You can configure them to use all the buttons on the joystick.