[email protected](0333- 4461420) Chapter # 3 INPUT of system.

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Chapter # 3Chapter # 3

INPUT of system INPUT of system


Input DevicesInput Devices

The data or instructions you type into the The data or instructions you type into the

computer are called computer are called inputinput Input devices used to get data into a system.Input devices used to get data into a system. Get data into a system as accurately, least Get data into a system as accurately, least

amount of time.amount of time. It’s a cheap device.It’s a cheap device.


Examples of Input DevicesExamples of Input Devices KeyboardKeyboard MouseMouse Tracker ball Tracker ball Touch sensitive padTouch sensitive pad Joystick Joystick Light pen Light pen Touch screen Touch screen Graphics tablets Graphics tablets Magnetic Strip ReaderMagnetic Strip Reader Bar Code readerBar Code reader Digital camerasDigital cameras Web CamerasWeb Cameras

OCR OCR MICRMICR OMROMR Punched CardPunched Card Kimball tagKimball tag Voice recognition Voice recognition MicrophoneMicrophone EPOSEPOS EFTPOSEFTPOS Video digitiserVideo digitiser ScannerScanner Touch Phone TelephoneTouch Phone Telephone


1.Keyboard1.Keyboard

Keyboard is the oldest and most familiar of all input Keyboard is the oldest and most familiar of all input devicesdevices

Keyboard are intelligent devices and contain their Keyboard are intelligent devices and contain their own chips.own chips.

The microprocessor scans the keyboard hundreds of The microprocessor scans the keyboard hundreds of second to see if a key has been pressed .second to see if a key has been pressed .

The CPU translate that key and convert into ASCII The CPU translate that key and convert into ASCII code.code.

A standard keyboard called QWERTY keyboard.A standard keyboard called QWERTY keyboard.


Concept or Ergonomic KeyboardConcept or Ergonomic Keyboard

New keyboards, called concept New keyboards, called concept keyboards, have been developed for keyboards, have been developed for ergonomicsergonomics

The goal of this keyboard is to The goal of this keyboard is to provide comfort and safety.provide comfort and safety.

The user who spends a lot of time in The user who spends a lot of time in typing may experience repetitive typing may experience repetitive injuries of wrist and hand. injuries of wrist and hand.

Higher typing speeds can be Higher typing speeds can be achieved.achieved.


Cordless keyboardCordless keyboard

That requires no wiresThat requires no wires It is also called wireless keyboards.It is also called wireless keyboards. It transmits data using wireless technology like It transmits data using wireless technology like

radio waves or light wavesradio waves or light waves


Special keyboardsSpecial keyboards

These keyboards make it easy for blind users to These keyboards make it easy for blind users to input data into a computerinput data into a computer

There are also keyboards with large coloured keys There are also keyboards with large coloured keys that are easier to see.that are easier to see.

Each key is about one inch square.Each key is about one inch square.


AdvantagesAdvantages

Most computers come with a keyboard Most computers come with a keyboard supplied supplied

People are used to using keyboards to enter People are used to using keyboards to enter data, they need very little training data, they need very little training

A skilled typist can enter data very quickly A skilled typist can enter data very quickly Specialist keyboards are available e.g. Specialist keyboards are available e.g.

ergonomic, gaming keyboards ergonomic, gaming keyboards


DisadvantagesDisadvantages

It is easy to make mistakes when typing in data It is easy to make mistakes when typing in data If you can't touch type, it can be time consuming If you can't touch type, it can be time consuming

to enter data to enter data Keyboards are not suitable for creating diagrams Keyboards are not suitable for creating diagrams Disabled people often find keyboards difficult to Disabled people often find keyboards difficult to

use use Excessive use can lead to R.S.I. Excessive use can lead to R.S.I.


2.Mouse2.Mouse

That translate its movement on the desktop That translate its movement on the desktop into digital information.into digital information.

Moving the mouse produces movement of Moving the mouse produces movement of cursor or the pointer on the screen.cursor or the pointer on the screen.

The mouse is also provided with buttons to The mouse is also provided with buttons to press.press.


Technologies Technologies

Movement of ball bearing is used to produce Movement of ball bearing is used to produce electrical signal.electrical signal.

Small lights under the mouse are reflected on Small lights under the mouse are reflected on the photoelectric cells.the photoelectric cells.


usesuses

To select options from a menu or form a set of To select options from a menu or form a set of icons icons

To position the cursor when editing text or To position the cursor when editing text or using a design package.using a design package.

To draw shapes.To draw shapes. It selects a position on the screen more quickly It selects a position on the screen more quickly

than is possible with a keyboard.than is possible with a keyboard.


3.Joysticks 3.Joysticks

Is similar to tracker ball.Is similar to tracker ball. Is a device which enables the user to control Is a device which enables the user to control

movement on the screen by a small lever.movement on the screen by a small lever. The lever can be moved in any direction.The lever can be moved in any direction. Some joysticks give more control on the screen.Some joysticks give more control on the screen.UsesUses Controlling objects in computer games Controlling objects in computer games Producing graphicsProducing graphics Scanners in hospitalsScanners in hospitals


4.Light Pen 4.Light Pen

Is a pen shaped device, held in the hand which Is a pen shaped device, held in the hand which can detect the presence or absence of lightcan detect the presence or absence of light

It is connected by the cable to a recording It is connected by the cable to a recording device or to a computer or computer terminal.device or to a computer or computer terminal.

Electrical signals are sent along the cable Electrical signals are sent along the cable indicating whether or not light of sufficient indicating whether or not light of sufficient intensity is being sensed.intensity is being sensed.


Uses Uses

To detect bar codesTo detect bar codes To indicate a point on the screen To indicate a point on the screen It removes the need to type or write.It removes the need to type or write. It is faster than typing.It is faster than typing.Disadvantage:Disadvantage:It can only record the presence or absence of It can only record the presence or absence of

light.light.It only works with software written for it.It only works with software written for it.


5.Graphics Tablet5.Graphics Tablet

Is also known as digitizing or digitizing pad.Is also known as digitizing or digitizing pad. The digitize data means to convert it from The digitize data means to convert it from

analog form to digital.analog form to digital. A design is put on the board and its shape is A design is put on the board and its shape is

traced out with the stylus.traced out with the stylus. Electrical signals sent to the computer record Electrical signals sent to the computer record

the position of the stylus.the position of the stylus. Encoding the picture into binary formEncoding the picture into binary form


Uses Uses

It can be used to digitize drawings with great It can be used to digitize drawings with great accuracy.accuracy.

Reproducing drawings and designsReproducing drawings and designs Producing layouts of printed circuit boards.Producing layouts of printed circuit boards. Digitizer Maps.Digitizer Maps.


6.Touch Pad /Track Pad6.Touch Pad /Track Pad

Is a small, flat surface over which the user moves his Is a small, flat surface over which the user moves his finger.finger.

The movement of the finger moves the cursor on the The movement of the finger moves the cursor on the screen.screen.

A touch pad also has one or more buttons near it .A touch pad also has one or more buttons near it . These buttons like mouse buttons.These buttons like mouse buttons. Touch pads are commonly used with notebook Touch pads are commonly used with notebook

computerscomputers


Touch screen Touch screen

Is a video display screen that receives input Is a video display screen that receives input from the touch of fingerfrom the touch of finger

ExamplesExamples ATM ATM Petrol Pumps Petrol Pumps


Magnetic Strip Magnetic Strip Is a short length of magnetic tape stuck on the surface Is a short length of magnetic tape stuck on the surface

of a tag, card or document.of a tag, card or document. On plastic tags or cards the strip is sealed in.On plastic tags or cards the strip is sealed in. Tags with stripes identify the item they are attached Tags with stripes identify the item they are attached

to.to.Examples:Examples: On credit card On credit card On bank cardsOn bank cards A phone Card A phone Card Cash issue TerminalsCash issue Terminals



It is simple to produce.It is simple to produce. It is not easily damaged.It is not easily damaged. It stores a large no of characters.It stores a large no of characters.

DisadvantagesDisadvantages The data can be changed or erased by The data can be changed or erased by

magnetic field. magnetic field.


7.Barcodes Readers7.Barcodes Readers Is set of parallel printed lines of differing thickness, Is set of parallel printed lines of differing thickness,

which represent a number.which represent a number. The number represented by the bars is also printed above The number represented by the bars is also printed above

or below the bar code.or below the bar code. When bar code are used on shop goods, the number When bar code are used on shop goods, the number

coded identifies the product and have following coded identifies the product and have following information information

1.1. Country of region Country of region 2.2. Manufacturer Manufacturer 3.3. An item number for the product.An item number for the product.Examples:Examples: Used in BarcodesUsed in Barcodes Library System Library System Warehouse stock Warehouse stock



Printed easily Printed easily The type of item or its price does not have to The type of item or its price does not have to

be repeatedly written down or typed.be repeatedly written down or typed.Disadvantages:Disadvantages: bar codes cannot be changed and thus there are bar codes cannot be changed and thus there are

unsuitable prices.unsuitable prices. Bar codes only be read by machine.Bar codes only be read by machine. Only numbers can be coded in this way.Only numbers can be coded in this way.


8.Optical Card reader (OCR)8.Optical Card reader (OCR)

Is a technology that reads typewritten , computer Is a technology that reads typewritten , computer printed or handwritten documents.printed or handwritten documents.

It translate the image into a form that can be It translate the image into a form that can be recognized by computer.recognized by computer.

OCR devices read printed characters using OCR font.OCR devices read printed characters using OCR font. An OCR device determines the shapes of characters An OCR device determines the shapes of characters

by detecting patterns of light and dark.by detecting patterns of light and dark.


Uses Uses

In department stores In department stores To scan financial documents such as companyTo scan financial documents such as company


9.Optical Mark Recognition 9.Optical Mark Recognition (OMR)(OMR)

It is also called mark sensing device.It is also called mark sensing device. It uses light to scan input data to convert it into It uses light to scan input data to convert it into

electrical/digital signal.electrical/digital signal. The signals are then sent to the computer for further The signals are then sent to the computer for further

processing.processing. ExamplesExamples Voting ballot Voting ballot Multiple choice answer sheet markingMultiple choice answer sheet marking Enrollment formsEnrollment forms


Mark sheet (OMR)Mark sheet (OMR)



In OMR there is typing involve so errors and takes In OMR there is typing involve so errors and takes time is less time is less

Reduces the cost of inputting large amount of data Reduces the cost of inputting large amount of data The method is useful when results of the test are The method is useful when results of the test are

needed very quickly needed very quickly DisadvantagesDisadvantages Readers are very expansiveReaders are very expansive Only certain fonts are acceptable.Only certain fonts are acceptable. There is high rejection rateThere is high rejection rate


10.Magnetic ink character reader 10.Magnetic ink character reader (MICR)(MICR)

Characters are printed Characters are printed using an ink containing using an ink containing iron oxide.iron oxide.

As the document passes As the document passes into the reader the ink is into the reader the ink is magnetized, so that the magnetized, so that the character shapes can then character shapes can then be recognized electrically.be recognized electrically.


Use Use It is used by banks industry for check It is used by banks industry for check

processing.processing. Each check contains MICR characters at the Each check contains MICR characters at the

lower left edge.lower left edge. These characters represent check These characters represent check

number ,bank number and account numbernumber ,bank number and account number

Branch codeCheque number

Account number



Documents can still be read when folded, Documents can still be read when folded, written on written on

DisadvantagesDisadvantages Readers are very expansive Readers are very expansive Only certain fonts are acceptable.Only certain fonts are acceptable.


11.Punched cards11.Punched cards

Contains holes in different positions which mean Contains holes in different positions which mean something when they are read by a reader.something when they are read by a reader.

Punched cards were the main method of entering data Punched cards were the main method of entering data into computers.into computers.

Example: Example: The clock card which is used to record the hours a The clock card which is used to record the hours a

person works so that wages can be calculated.person works so that wages can be calculated.


12.Kimball tag 12.Kimball tag

Kimball tags are the small cards with holes Kimball tags are the small cards with holes punched in them that you see attached to punched in them that you see attached to clothing in certain shops.clothing in certain shops.

When you buy the goods, one of the tags is When you buy the goods, one of the tags is removed and sent for processing to a computer removed and sent for processing to a computer centre.centre.


Advantage Advantage

Stock is reordered without any writing or Stock is reordered without any writing or typing the data.typing the data.

DisadvantagesDisadvantages:: They are small and are easily mislaid.They are small and are easily mislaid.


Voice Recognition Voice Recognition

Using a microphone human speech is coded Using a microphone human speech is coded into a sequence of electrical signals.into a sequence of electrical signals.

The computer searches a set of stored patterns The computer searches a set of stored patterns for the sound which has been input for the sound which has been input

It is now popular for inputting data into word It is now popular for inputting data into word processing or database packages.processing or database packages.


AdvantageAdvantage

Useful for handicapped people with limited Useful for handicapped people with limited movementmovement

No typing or data preparation is necessary.No typing or data preparation is necessary.

Disadvantage:Disadvantage: Few words can be recognized and the error Few words can be recognized and the error

rate is high.rate is high. Not suitable in noisy places.sNot suitable in noisy places.s


13.Microphone13.Microphone

Is used for input device for a speech Is used for input device for a speech recognition system.recognition system.

The voice pattern of user is then converted into The voice pattern of user is then converted into instructions to the operating system or instructions to the operating system or application software or text.application software or text.

Uses as voice mail messages Uses as voice mail messages


14.Electronic point of sale Terminal 14.Electronic point of sale Terminal (EPOS)(EPOS)

Are the cash registers which act as the Are the cash registers which act as the terminals to a main computer system terminals to a main computer system

Providing customers with itemised bills.Providing customers with itemised bills. Give useful management informationGive useful management information


15.Electronic Fund transfer at point 15.Electronic Fund transfer at point of sale (EFTPOS)of sale (EFTPOS)

Similar to EPOS terminal but some additional Similar to EPOS terminal but some additional features.features.

They are able to transfer funds from your bank They are able to transfer funds from your bank account directly to a store’s switch card called account directly to a store’s switch card called a debit card.a debit card.

Example:Example: Switch cardSwitch card


AdvantageAdvantage

You can use it instead of a cheque.You can use it instead of a cheque. Faster method of payment Faster method of payment Money is instantly transferred into its account.Money is instantly transferred into its account. You can also get cash back using your debit card.You can also get cash back using your debit card.

Disadvantage:Disadvantage: They may be stolen and they are said to encourage They may be stolen and they are said to encourage

people to spend more money.people to spend more money.


16.Video Digitizer16.Video Digitizer Is the combination of hardware and Software that Is the combination of hardware and Software that

converts an analogue video signal into a digital signal converts an analogue video signal into a digital signal in computer’s memoryin computer’s memory

Is used to convert a frame from a video sequence into Is used to convert a frame from a video sequence into a picturea picture

Each frame from the video is converted using video Each frame from the video is converted using video digitiser.digitiser.

It may be played back in any required sequence.It may be played back in any required sequence. Is also called image grabbing or frame grabbingIs also called image grabbing or frame grabbing Take up a lot of main memory and when stored use a Take up a lot of main memory and when stored use a

large amount of disk space large amount of disk space


UsesUses

Digitiser pictures Can be printed in a Digitiser pictures Can be printed in a magazine or document magazine or document

To make television adverts and to produce pop To make television adverts and to produce pop videos.videos.


17.Scanner 17.Scanner

Read data or information from the sourceRead data or information from the source Source could be written document, a price tag, Source could be written document, a price tag,

a graphics image , or photograph a graphics image , or photograph To scan text or images which manipulated in To scan text or images which manipulated in

some way before being printed some way before being printed


Types of Scanner Types of Scanner

Optical Scanner Optical Scanner Optical Reader Optical Reader


Optical Scanner Optical Scanner

It is a light sending input device.It is a light sending input device. The scanner image depend upon resolutionThe scanner image depend upon resolution Image will be sharper if the scanner provides high Image will be sharper if the scanner provides high

resolution resolution it provide OCR Software it provide OCR Software Different types of Optical Scanner are Different types of Optical Scanner are Flatbed Scanner Flatbed Scanner Sheetfed Scanner Sheetfed Scanner Handheld ScannerHandheld Scanner


18.Digital Camera 18.Digital Camera

Is used to store, picture in digital form.Is used to store, picture in digital form. Store images using different ways like floppy disk, Store images using different ways like floppy disk,

memory stick, mini CD ,PC Card and micro device.memory stick, mini CD ,PC Card and micro device. Can be connected to a computer easily through USB Can be connected to a computer easily through USB

port.port. Image resolution for digital camera measured by Image resolution for digital camera measured by

megapixels.megapixels. Higher resolution photo takes up more memory . Higher resolution photo takes up more memory .



No film is needed No film is needed No expensive developing costsNo expensive developing costs Pictures are in digital form so it can easily sent Pictures are in digital form so it can easily sent

over the internetover the internet You can adjust the size of imageYou can adjust the size of image


19.Web camera ( Web Cams)19.Web camera ( Web Cams)

Is simply a digital camera that is Is simply a digital camera that is used to capture still images and used to capture still images and video imagesvideo images

These images can then be These images can then be transmitted to a computer where transmitted to a computer where they are stored in graphics format they are stored in graphics format

Pictures can be used on the Pictures can be used on the websiteswebsites

Camera placed on top the screen Camera placed on top the screen such a system allow video such a system allow video conferencing conferencing


UsesUses

Advertising Advertising Checking on children in nurseriesChecking on children in nurseries Checking on the weather on the other part of Checking on the weather on the other part of

the worldthe world


20.Touch tone Telephones20.Touch tone Telephones

Having a different tone of each number when Having a different tone of each number when pressed keypressed key

Using these different tones that the numbers Using these different tones that the numbers dialed are recognized and routed to correct dialed are recognized and routed to correct telephone telephone

Can be used as a data entry device Can be used as a data entry device Home banking system use touch tone Home banking system use touch tone

telephonetelephone


Output DeviceOutput Device

Output device provide results in a suitable Output device provide results in a suitable form after data processing.form after data processing.

Output devices are used to get data out of a Output devices are used to get data out of a system.system.

They should be able to do this as accurately They should be able to do this as accurately and quickly as possible, and with the minimum and quickly as possible, and with the minimum of human intervention.of human intervention.


Output Device Output Device

Visual devices (including Visual Display Units Visual devices (including Visual Display Units [VDUs], screens, and monitors)[VDUs], screens, and monitors)

Hard copy devices (including ink jet printer, laser Hard copy devices (including ink jet printer, laser printers, dot-matrix printers, and plotters)printers, dot-matrix printers, and plotters)

Sound devicesSound devices Computer controlled devices (including robots)Computer controlled devices (including robots)


Monitor or VDU Monitor or VDU

Most common output deice Most common output deice It is known as display screenIt is known as display screen The output display by monitor is called soft The output display by monitor is called soft

copy so it is ideal for showing the results from copy so it is ideal for showing the results from an enquire where no printed is needed.an enquire where no printed is needed.


Features of Monitor Features of Monitor

Size Size Color Color ResolutionResolution Video Display Adapter Video Display Adapter


Types of Monitor Types of Monitor

CRT CRT Flat Panel Monitors Flat Panel Monitors Touch screen Monitors Touch screen Monitors


Cathode Ray Tube (CRT)Cathode Ray Tube (CRT)

Creates the image on the screen through Creates the image on the screen through electronic beamelectronic beam

This is same type that is use in Television This is same type that is use in Television It consists of one or more guns It consists of one or more guns These guns generate red ,green and blue These guns generate red ,green and blue

(RGB) colors.(RGB) colors.


Liquid Crystal Display (LCD) Liquid Crystal Display (LCD)

LCD screens are most often seen on portable LCD screens are most often seen on portable or laptop computersor laptop computers

These are used in these applications because These are used in these applications because they are small and light.they are small and light.

Also used where space is at the premium.Also used where space is at the premium. The molecules this substances line up in such a The molecules this substances line up in such a

way that the light behind the screens and way that the light behind the screens and creates an image.creates an image.

Use in banks and Multinational companiesUse in banks and Multinational companies


Graphical Display unit ( GDU)Graphical Display unit ( GDU)

Larger than VDU and have greater resolutions Larger than VDU and have greater resolutions lines on the screen don’t look as through they lines on the screen don’t look as through they

are made up of lots of tiny dots.are made up of lots of tiny dots. Are often used in conjunction with light pensAre often used in conjunction with light pens


Printers Printers

It prints character ,symbols and graphics on It prints character ,symbols and graphics on paper.paper.

Print resolution is commonly measured in dots Print resolution is commonly measured in dots per inch (dpi)per inch (dpi)

Different types of printer are Different types of printer are Impact Printer Impact Printer Non Impact Printer Non Impact Printer


Impact Printer Impact Printer

Its act like a typewriter Its act like a typewriter It prints characters or images by striking a It prints characters or images by striking a

print hammer or wheel against an inked ribbonprint hammer or wheel against an inked ribbon Dot matrix printer Dot matrix printer Line printer Line printer Daisy wheel Printer Daisy wheel Printer


1.Dot Matrix printer 1.Dot Matrix printer

It produces printed images when tiny pins on a print It produces printed images when tiny pins on a print head strike an inked ribbonhead strike an inked ribbon

When ribbon pressed against the paper, it creates dots When ribbon pressed against the paper, it creates dots that they form characters and graphicsthat they form characters and graphics

Which can transfer print through layers of paper.Which can transfer print through layers of paper. Able to print multi-part sheet where Able to print multi-part sheet where It generates lot of noise ,its print quality is not good It generates lot of noise ,its print quality is not good


2.Line printer2.Line printer

Is a fast impact printer Is a fast impact printer It prints a entire line at a time It prints a entire line at a time Its speed is measured in line per minuteIts speed is measured in line per minute


3.Daisy wheel printer 3.Daisy wheel printer

Similar to typewriterSimilar to typewriter Uses print wheel Uses print wheel A motor rotates the wheel.A motor rotates the wheel. Its slower than Dot matrix but better in qualityIts slower than Dot matrix but better in quality


2. Non Impact Printer2. Non Impact Printer

Prints characters and graphics on a piece of Prints characters and graphics on a piece of paper without striking the paper.paper without striking the paper.

These printers are faster than impact printers These printers are faster than impact printers Inkjet printer Inkjet printer Laser printer Laser printer Thermal printerThermal printer


1.Inkjet printer1.Inkjet printer It prints characters and graphics by spraying tiny It prints characters and graphics by spraying tiny

drops of liquid ink on paper drops of liquid ink on paper The print head of an inkjet printer consists of nozzles The print head of an inkjet printer consists of nozzles It has two cartridges black and whiteIt has two cartridges black and white These printers can produce quality text and graphics These printers can produce quality text and graphics

in both black and white color in both black and white color slower than laser printer but faster than dot matrix slower than laser printer but faster than dot matrix

printer printer They can print 1 to 6 pages per minute They can print 1 to 6 pages per minute Cheaper in price Cheaper in price Satisfactory in color Satisfactory in color


2.Laser Printer 2.Laser Printer

Creates image on the paper by the laser beam Creates image on the paper by the laser beam Also called page printer because they print Also called page printer because they print

complete page at a timecomplete page at a time It contain toner It contain toner Throws magnetic powder on paper in the form Throws magnetic powder on paper in the form

of microscopic dots of microscopic dots


Advantages Advantages

Print a page at a time so it is fast and it print Print a page at a time so it is fast and it print pages 10ppmpages 10ppm

They produce high quality of text and graphics They produce high quality of text and graphics They are quiet in operation compared with dot They are quiet in operation compared with dot

matrix matrix Equipped with paper trays for both the input Equipped with paper trays for both the input

and the output papers and the output papers


DisadvantagesDisadvantages

Are more expensive than dot matrix or ink-jet Are more expensive than dot matrix or ink-jet printer printer

They are quite large and can take up lot of disk They are quite large and can take up lot of disk space space

Quite complex so the repair bills can be high Quite complex so the repair bills can be high Multi part stationary cannot be used Multi part stationary cannot be used


Thermal printer Thermal printer

Is a printer that uses heat process to transfer Is a printer that uses heat process to transfer colored dyes or inks to the paper colored dyes or inks to the paper

Is the best color printers currently available Is the best color printers currently available but it is very expensive but it is very expensive


Plotters Plotters

Is an output device that is used to produce Is an output device that is used to produce image quality graphics in variety of colors image quality graphics in variety of colors

Used to create maps, architecture drawings, Used to create maps, architecture drawings, graphs and charts graphs and charts

A plotter works by drawing lines on paper A plotter works by drawing lines on paper using pens held in a mechanical arm using pens held in a mechanical arm

It may be in form ofIt may be in form of Flatbed Plotter Flatbed Plotter Drum plotter Drum plotter


Flatbed Plotter Flatbed Plotter

Used to plot or draw images.Used to plot or draw images. It contains pens for drawing images. It contains pens for drawing images. The paper is placed on table like surface The paper is placed on table like surface Software instructs the pens to move down on Software instructs the pens to move down on

the paper the paper


Drum PlotterDrum Plotter

Uses a rotating drum or Uses a rotating drum or cylinder cylinder

The drawing pens are The drawing pens are mounted on the drum mounted on the drum

The pens move to the left The pens move to the left and right as the drum and right as the drum rotates rotates

Advantage of drum plotter Advantage of drum plotter is that the length of the is that the length of the plot is almost unlimited plot is almost unlimited


Voice OutputVoice Output

Visually people find the spoken word from the Visually people find the spoken word from the computer computer

Special software is used for this process Special software is used for this process In a word processor each letter is typed and it In a word processor each letter is typed and it

can hear with headphone. can hear with headphone.


Audio Output Audio Output

An audio device translate audio information An audio device translate audio information from the computer into sounds that people can from the computer into sounds that people can understandunderstand

Speakers Speakers Headsets Headsets


Electrical SignalsElectrical Signals Sometimes the output from one computer system can simply Sometimes the output from one computer system can simply

be a series of electrical signalbe a series of electrical signal In this case one computer is being used as a terminal and work In this case one computer is being used as a terminal and work

that is done sent as electrical signals that is done sent as electrical signals Electrical signals can be output and used to control all kinds of Electrical signals can be output and used to control all kinds of

devices such as devices such as Heating system Heating system Alarms Alarms Robots Robots Actuators Actuators Computer aided manufacturing (CAM)Computer aided manufacturing (CAM) Computerised numerical control (CNC) Computerised numerical control (CNC)


Computer controlled devices - Computer controlled devices - RobotsRobots

A typical computer controlled device used in computer-aided manufacturing – a robotic arm

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