Input and output devices
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This document discusses various input and output devices for computers. It describes keyboards, mice, scanners, trackballs, light pens, and bar code readers as common input devices. Keyboards allow text entry and have letter, number, function, and control keys. Mice are pointing devices that control cursor movement. Scanners convert printed text and images into digital format. Trackballs and light pens provide alternative means for cursor control. Bar code readers convert bar codes into data. For output, monitors display information and come in CRT and LCD varieties. Printers produce hard copies and are classified as impact or non-impact. Speakers output sound and projectors display computer images on large surfaces.
Input and output devices
- 2. Input device Input device is a hardware component which allow us enter data and Information onto a computer. Input devices are- (1) Keyboard Keyboard is the most common input device of a Computer System.The keyboard is used to enter text andinformation into the computer. .
- 3. (1) Typing Keys-These keys include the letter keys (A-Z) and digit keys (0-9) which generally give same layout as that of typewriters. (2)Numeric Keypad-It is used to enter numeric data or cursor movement. Generally, it consists of a set of 17 keys that are laid out in the same configuration used by most adding machines and calculators. (3)Function Keys-The twelve function keys are present on the keyboard which are arranged in a row at the top of the keyboard. Each function key has unique meaning and is used for some specific purpose. (4)Control keys-These keys provide cursor and screen control. It includes four directional arrow keys. Control keys also include Home, End, Insert, Delete, Page Up, Page Down, Control(Ctrl), Alternate(Alt), Escape(Esc).
- 4. (2) Mouse It’s a pointing device. The mouse is rolled over themouse pad, which in turn controls the movement of the cursor in the screen. We can click, double click or drag the mouse . Advantages Easy to use Not very expensive Moves the cursor faster than the arrow keys of keyboard
- 5. (3) Scanner Scanners are used to enter information directly in to the computers memory. This device works like a Xerox machine.The Scanner converts any type of printed or written information including photographs into digital pulses which can be manipulated by the compute.
- 6. (4) Track Ball Track ball is similar to the upside- down design of the mouse. The user moves the ball directly, while the device itself remains stationary. The user spins the ball in various directions to effect the screen movements.
- 7. (5) Light Pen This is an input device which is used to draw lines or figures on a computer screen. It’s touched to the CRT screen where it can detect raster on the screen as it passes.
- 8. (6) Bar Code Reader This device reads bar codes and coverts them into electric pulses to be processed by a computer. A bar code is nothing but data coded in form of light and dark bars.
- 9. Output device An output device is any hardware component showing information processed by a computer in the form of text, images, sounds, or other media. Output devices are:- (1)Monitor Monitor is the most important output device of a computer system. The monitor is the display screen of a computer. Cathode Rays Tube (CRT) and Liquid Crystal Display (LCD) are the two types of Monitors.
- 10. There are two kinds of viewing screen used for monitors. • Cathode-Ray Tube (CRT) • Flat- Panel Display (2) Printers Printer is an output device, which is used to print information on paper. There are two types of printers: • Impact Printers • Non-Impact Printers
- 11. ●Impact printers:- The impact printers print the characters by striking them on the ribbon which is then pressed on the paper. Characteristics of Impact Printers are the following: • Very low consumable costs. • Very noisy. • Useful for bulk printing due to low cost. • There is physical contact with the paper to produce an image. These printers are of two types • Character printers • Line printers
- 12. Non-impact printers print the characters without using ribbon. These printers print a complete page at a time so they are also called as Page Printers. These printers are of two types • Laser Printers • Inkjet Printers Characteristics of Non-impact Printers • Faster than impact printers. • They are not noisy. • High quality. • Support many fonts and different character size.
- 13. Speaker is a define as an electrical device used to make sound or music louder .An example of speaker is how listen music in a car (4)projecter A projector is an output device that can take images generated by a computer and reproduce them on a large,flatsurface. For example, projectors are used in meetings to help ensure that all participants can view the information being presented.
- 14. Thank you ●●●