Presented to : Miss Ayesha Javed

Presented by : Zobia Aziz (121)

Input and Output Devices

Introduction

Do you ever wonder how information

gets into your computer and how comes out in a form you can use ? It is possible with the help of input and

output devices.

Input DevicesDefinition :

“An electromechanical device that can be used to enter data and instructions into a computer.”

Keyboard“A keyboard is a human interface device which is represented as a layout of button or keys.”It has some Features as• Typewriter keyboard with numeric keypad• Special purpose keys• Toggle and combination keys

Pointing DevicesDefinition :

“An input device used to control a pointer on the screen.”

Mouse:“mouse can be used to Control and manipulate cursor movement on monitor.” Types of Mouse : i) Mechanical ii) Optical iii) Cordless or wireless

Some pointing devices are

TrackballPointing StickJoystickTouch PadTouch Screen Light Pen

Optical Input Devices“optical input devices that uses light as a source of input. They eliminate the need for manual entry of data, thus accuracy increases.

Scanner:“scanners can be used to copy the image or text on paper into a digital format that can be used by the computer.”

Other Optical Input Devices are:Optical scanners

FlatbedPortable

Bar code readers:“A Barcode Reader is an electronic device which is used for reading printed barcodes. This device directs a light beam across the bar code while it measures the amount of light which is reflected back. “

Character and mark recognition devices

Scanners that recognize special characters & marks Magnetic ink character recognition (MICR)Optical-character recognition (OCR)Optical-mark recognition (OMR)

Audio Input Devices Definition :

“Audio input devices record the analog sound and convert it into digital form for further processing.”Some Audio input devices are :

Voice recognition microphone

Musical Instrument Digital Interface

Video Input Definition : “ video input devices that can be used to entering full motion recording into a computer .“Some video input devices are

digital camera webcam

video capture card

Output DevicesDefinition “Output devices can be used to receive

information from the computer “The output can be in two forms:Soft copyHard copy

MonitorDefinition

“A monitor is a peripheral device which displays computer output on a screen . Screen output is referred to as soft copy”

Features Resolution-pixelsDot pitchRefresh ratSize

Types of monitors Cathode Ray Tube (CRT) Liquid crystal Display (LCD)

Printer Definition “A printer is a peripheral device that produces a

physical copy or hard copy of the computer’s output.”

Types of Printer :Impact Printers • Dot Matrix Printer• Daisy Wheel PrinterNon Impact Printers• Laser Printer• Ink-Jet Printer • Thermal Printer

Plotter Definition “A plotter is an output device that is used to produce high quality graphics in a variety of colors.”

Types of PlotterFlatbed PlotterDrum plotter

Audio output DevicesDefinition “Audio Output Devices can be used to translates audio information from the computer into sounds that people can understand.”

Common audio output devicesSpeakersHeadphones

ProjectorDefinition “Projector can be used to displays computer information on big screen so that many will able to see the show.”

Computer Output Microfilm (COM) This technology is used to record computer output as a microscopic film images.

Information is recorded on a roll of film.

COM devices are used applications where there are large volumes of data.

Combination Input and Output Devices

Many devices combine input and output capabilities

Fax machinesMultifunction devicesInternet telephones

known as Telephonyand Voice-over IP (VoIP)

Terminals

Fax machinesDefinition :“A fax machine refers to a device or equipment that does telephonic transmission of scanned material. It scans the original document and converts it into a bitmap. It then uses electronic signals to send the document to another recipient. “

TerminalsAn input and output deviceConnects to a mainframe or server

Types of terminalsDumb terminal Intelligent terminalNetwork terminalInternet terminal