2. INPUT DEVICEOUTPUT DEVICE 1.KEYBOARD 2.JOYSTICK 3.SCANNER 4.LIGHT PEN 5.TOUCH SCREEN 1.MONITOR 2.LCD 3.PRINTER 4.PLOTTER Some commonly used input/output devices are listed in table below::

4. It is a text base input device that allows the user to input alphabets,numbers and other character. 1.Alphanumeric keypad: It consists of keys for english alphabet,0 to 9 numbers, and special characters like +,-,/,() etc. 2.Function keys: there are 12 function keys labeled F1,F2……..F12. 3.Special function keys: these keys have special functions assigned to them and can be used for those specific purposes.(eg:enter key, spacebar key, backspace key, insert key, delete key etc. 4.Numeric keypad: it is located on the right side of the keyboard and consists of keys having numbers(0 to 9)and mathematical operation(*,/,-,+) defined them. 5.Cursor movement keys: these are arrow keys used to move the cursor in the direction indicated by the arrow(up,down,left,right).

6. A joystick is an input device. Consisting of a stick that pivots on a base and reports its angle or direction to the device it is controlling. Joysticks are often used to control video games. usually have one or more push-buttons whose state can also be read by the computer. A popular variation of the joystick used on modern video game consoles is the analog stick. video game consolesanalog stick Joysticks are also used for controlling machines such as cranes, trucks, underwater unmanned vehicles, wheelchairs, etc.

7. Printers are used to produce output. Based on the technology used, they can be classified as Impact or Non-impact printers.

8. It use the typewriting printing mechanism where in a hammer strikes the paper through a ribbon in order to produce output. Examples are Dot-matrix and Character printers.

9. Non-impact printers do not touch the paper while printing. They use chemical, heat or electrical signals to etch the symbols on paper. Examples are Inkjet, Laser, Thermal.

11. These use rows of needles which are made to impact with an ink-ribbon to make the pattern of the required character on the paper. Each character as a group of small dots. Tiny metal rod, also called a "wire" or "pin“. Speeds range from 200 to 400 cps. They are relatively cheap to buy.

12. very slow light or poor print quality paper jams missing print paper out dark smudges flecks of ink

14. These work in a similar way to photocopiers. A laser beam is used to create an electric charge which attracts special black dust to it. The dust is then transferred to the paper to produce the printed output. It is a very high quality print. They are also relatively expensive.

15. A liquid crystal display (LCD) is a flat panel display.flat panel display They are used in a wide range of applications, including computer monitors, television, instrument panels, aircraft cockpit displays, signage, etc. computer monitorstelevisionaircraft cockpit displayssignage They are common in consumer devices such as video players, gaming devices, clocks, watches, calculators, and telephones.clockscalculatorstelephones They are usually more compact, lightweight, portable, less expensive, and easier on the eyes. Its low electrical power consumption enables it to be used in battery-powered electronic equipment. batteryelectronic The earliest discovery leading to the development of LCD technology, the discovery of liquid crystals, dates from 1888. By 2008, worldwide sales of televisions with LCD screens had surpassed the sale of CRT units.