Input Devices And Output Devices

Input Devices And Output Devices are the supporting units surrounding the central processor of any computer. Their purpose is to provide an information link between the outside world and central processing unit (CPU). In computing parlance, they act as an interface, translate the read symbols into binary patterns that can be understood & processed by CFU. Similarly they can translate the binary patterns back to symbols which can he displayed on output devices. You can download Input Devices And Output Devices PDF, which is given below.

Input Devices

The term “Hardware” is used to describe all the physical components attached with a computer system. Some hardware are required for the functioning of a computer whereas others are option for additional functionality. The input devices are the hardware that are used to transfer input to the computer. The input can be in the form of text, graphic, sound or image. For these various types of inputs, we have various types of input devices.

(A) Keyboard – More common and very popular input device is Keyboard: Layout of Keyboard is same as that of Type writer with some additional keys. Generally keyboards are of two sizes 84 keys or 101/102 keys, but now 104 keys or 108 key keyboard is also available for Windows and Internet.

Data is entered into computer by simply pressing various keys. The most common layout of a keyboard is the QWERTY. It is named so because the first six keys icon the top row of letters are Q, W, E, R, T, and Y.

(B) Mouse – Mouse is very popular cursor-control device A mouse is a small box with a round ball at the bottom. There are two or three depression switches on the top. A mouse is used to manipulate cursor (arrow) at the screen. As mouse is rolled on a flat surface. Pointer moves on the screen. The movement of mouse along the X-axis helps in horizontal movement of the cursor and movement along the y-axis helps in vertical movement of the cursor on the screen. Mouse can’t be used to enter text. Therefore they are used in conjuction with a keyboard.

(C) Joystick – Joystick is also a pointing device which is used to move cursor position on a monitor screen. Joystick is a stick having a spherical ball at its both lower and upper ends. The lower spherical ball moves in a socket. The joystick can be moved in all four directions. The function of joystick is similar to that of a mouse. It is mainly used in Computer Aided Designing (CAD) and playing computer games.

(D) Tracker Ball – This is an input device that is mostly used in notebook or laptop computer, instead of a mouse. This is a ball which is half inserted and by moving fingers on ball, pointer can be moved. It is sometimes considered better than mouse because it requires little arm movement and less desktop space.

(E) Voice Systems (Voice Recognition) – Voice recognition is one of the newest, most complex input techniques used to interact with the computer. The user inputs data by speaking into a microphone. The simplest form of voice recognition is a one-word command spoken by one person. Each command is isolated with pauses between the words.

Voice recognizers are used in some graphics workstations as input devices to accept voice commands. The voice-system input can be used to initiate graphics operations or to enter data. These systems operate by matching an input against a predefined dictionary of words and phrases. But the number of words in the dictionary are limited thus allowing their use only to limited application areas.

(F) Web Camera – A webcam is a video capture device connected to a computer, often using a USB port. The most popular use is for videotelephony, permitting a computer to act as a videophone or video conferencing station. Webcams are often used for personal use in the home by parents who want to give distant relatives visual access to their children or want to monitor what goes on in the home while they are at work. People might also use webcams in the home to keep an eye on things while they are out of town or even just to see what their pets do all day. Businesses often use webcams for video conferencing, Some schools and day care facilities use a webcam to allow parents to see what their children do at school.

Webcams are known for low manufacturing costs and flexibility making them the lowest cost form of videotelephony.

Input And Output Devices PDF – Download

Output Devices

An output device is an electromechanical device, which accepts data from a computer and translates them into a form, which is suitable for use by the outside world (users). Output devices can be broadly classified into the following two types:

1. Soft-copy Output: Output which is not produced on a paper, is known as soft-copy output. They are temporary in nature. For example, output displayed on a terminal screen, or spoken out by a voice response system are soft- copy output.

• Monitor – Visual Display Unit (VDU), commonly called as monitor is the main output device of a computer. It consists of a Cathode Ray Tube (CRT), which displays characters as an output. It forms images from tiny dots, called pixels, that are arranged in a rectangular form. The sharpness of the image (screen resolution) depends upon the number of pixels.
• Video Controller – The video controller is an intermediary device between the CPU and the monitor. It contains the video-dedicated memory and other circuitry necessary to send information to the monitor for display on the screen. It consists of a circuit board, usually referred to simply as a card, which is attached to the computer’s motherboard.  There are different kinds of monitors depending upon the number of pixels (or resolutions) or the video controllers.
• Sound Cards and Speakers – An expansion board that enables a computer to manipulate and output sounds. Sound card enable the computer to output sound through speakers connected to the board, to record sound input from a microphone connected to the computer, and manipulate sound stored on a disk.

2. Hard-copy Output: Output which is produced on a paper, is known as Hard- Copy output. They are permanent in nature. For example, output produced by printers and plotters on paper are hard-copy output.

• Printers – Printer is the most important output device, which is used to print information on paper. Click here for Block diagram Of Computer. Download Input Devices And Output Devices PDF, which is given above.