Can be more difficult for people with restricted hand/wrist movement than using a keyboard for data entry
Easy to damage
Difficult to use if no flat surface

Uses of mouse

Opening, closing and minimising software
Grouping, moving and deleting files
Image editing
Controlling the position of a pointer

Touchpad

Used as a pointing device in many laptop computers
Buttons under the touchpad which serve the same function as the left and right buttons on a mouse

Uses of touchpad

Uses are the same as those of a mouse

Advantages of touchpad

Same as mouse
Integrated into the laptop computer
Portability
Big advantage if there are no flat surfaces available

Disadvantages of touchpad

Limited hand/wrist movement
More difficult to control the pointer
More difficult to use drag and drop

Trackerball

Are similar to a mouse, except that a ball is on the top or the side of the device
User controls the pointer on the screen by rotating the ball
Don not physically move, there is no need for a large amount of desk space

Advantages of trackerball

Easier to use than a mouse if the operator has problems with their wrist or hand
More robust than a mouse
Needs less desk space than a mouse or keyboard

Disadvantages of trackerball

Not supplied with the computer
User may need training
More costly
Not standard equipment

Remote control

Used for the operation of other devices using infrared signals

Uses of remote control

Televisions, satellite systems, DVD/Blu-ray players and Hi-Fi systems
Control multimedia systems
Industrial applications to remotely control processes, stop and start machinery

Advantages of remote control

Reasonable distance
Able to select operations from a distance

Disadvantages of remote control

Difficult to use if the operator has limited hand/wrist movement
It is easier to block the signal,for example, the walls in the building are ver thick

Joystick

Similar functions to a mouse and a trackerball
A pointer on the screen can be controlled

Uses of joystick

Used in video/computer games
Used in simulations (for example, flight simulators) to mimic actual controls

Advantages of joystick

Easier than a keyboard

Disadvantages of joystick

More difficult to control the on-screen pointer than a mouse

Driving wheel

An input device that is similar to a joystick

Uses of driving wheel

Used in video/computer games (for example, car racing games)
Used in simulators (for example, car-driving simulators) to mimic actual vehicle controls

Advantages of driving wheel

Easier than a keyboard or joystick to control steering movements

Disadvantages of driving wheel

Expensive input device
Mouse or joystick

Touch screens (as an input device)

User can choose an option by simply touching a button/icon on the screen.

Uses of touch screens

Automatic teller machines (ATMs)
Point of sale terminals (POS) in restaurants
Mobile phones, tablets and satellite navigation systems
Interactive white boards in education

Advantages of touch screens

Faster entry than keyboard or mouse
Very easy method
User-friendly method

Disadvantages of touch screens

Limited number of input options available
Screen get get very dirty

Scanners

Used to enter information from hard copy into a computer

Uses of scanners

Scan in documents and convert into a format for use in various software packages.
Scan in old/valuable documents/books
Scan in photographs
Requiring conversion to computer format

Advantages of scanners

Images can be stored for editing at a later date
To recover damaged documents and photographs

Disadvantages of scanners

Quality can be limited depending on how good a resolution the scanner is

Digital cameras

Largely replaced traditional film-based cameras
Stored on a memory card(solid state memory)
Transferred to a computer
Images are uploaded from camera and stored in a file in the computer
Can select photos to upload/discard
Printed out as photos
Used in slide show
Imported into software
Uploaded on the internet

Uses of digital cameras

Taking photographs
Data-capture device
Dentists use digital cameras to take photos of a patient’s teeth
Creation of virtual reality tours around houses, historical buildings, industrial plants

Advantages of digital cameras

Easier to produce better quality photographs
Easier and faster to upload photographs to a computer
No need to develop film and print out photographs
Memory cards can store many thousands of photographs

Disadvantages of digital cameras

Need to be computer literate to use the cameras properly
Transferring, storing and manipulating images requires computer knowledge
Some artistry lost because clever software corrects errors
Images often need to be compressed to reduce the amount of memory

Microphones

How to process

A microphone can convert sound waves into an electric current
The current produced is converted to a digital format
Computer can process it or store it

Uses of microphones

To input speech,sounds to be used in various applications
Input in voice-recognition software
Microphones can also be used as a sensor to pick up sound
Used in video-conferencing or Voice over Internet Protocol (VoIP) applications

Advantages of microphones

Faster to read than using a keyboard
Manipulate sound in real time using special software
Used in a voice activation system
Advantage of improving safety

Disadvantages of microphones

Sound files can use up a lot of computer memory
Voice-recognition software is not as accurate as typing in manually

Sensors

Uses of sensors

Type of sensor	Applications
Temperature	Used in automatic washing machines, central heating systems, automatic glasshouses, ovens
Pressure	Used in intruder alarm systems, washing machines, robotics, environmental monitoring
Light	Used in automatic glasshouses, automatic doors, intruder alarm systems, street lighting control
Sound/acoustic	Used in intruder alarm systems, monitoring liquid and powder flow in pipes
Humidity/moisture	Used in automatic glasshouses, environmental monitoring, in factories where moisture levels are crucial
pH	Used in automatic glasshouses, chemical processes, environmental monitoring

Advantages of using sensors

More accurate readings taken when compared to human operators
Readings are continuous
Is a continuous process
Will be initiated immediately
Systems can be automatic

Disadvantages of using sensors

Faulty sensors can give spurious results
Most sensors are analogue
Require conversion using ADC

Light pens

Input device
Contain sensors that send signals to a computer whenever light changes are detected
Only works with CRT monitors

Uses of light pens

Selecting objects on CRT screens
Drawing on screen with CAD packages

Advantages of light pens

Greater accuracy than touch screens
Small
Easy-to-use technology

Disadvantages of light pens

Problems with lag when drawing on screen
Only works with CRT monitors
Not that accurate when drawing
Rather dated technology

Direct data entry (DDE) devices

Direct data entry (DDE) devices are used to input data into a computer without the need for very much, if any, human interaction.

Card Readers

Magnetic stripe readers

Read information on the magnetic stripe
Back of a credit or debit card
Useful information: account number, sort code, expiry date and start date

Advantages of magnetic stripe readers

Fast data entry
Error free
Secure
Prevents access to restricted/secure areas

Disadvantages of magnetic stripe readers

Magnetic stripe gets damaged then data is lost
Does not work at a distance

Contactless debit card readers

Allow customers to pay for items worth up to a certain amount of money without entering their PIN
All contactless cards have a small chop that emits radio waves embedded in them

Advantages of using contactless cards

Faster transactions
Do not have to worry about typing errors
Chip in contactless card responds to the payment terminal reader
Unique number used for that transaction only

Disadvantages of using contactless cards

More expensive than normal credit/debit cards
Somebody standing behind you could steal your PIN and use it
Can take money twice if customer uses it as a chip and PIN card
Transactions are limited
Transactions have been carried out, in some countries, without the card holder

Chip and PIN readers

Similar to smart card readers
Use at EFTPOS(Electronic File Transfer Point Of Sale) terminals
Has a slot into which the card is placed and the chip is read
PIn is entered using keypad
Similar to contactless system except :

- customer has key in their PIN to make a transaction

- do not make use of radio frequency technology

Uses of chip and PIN readers

Restaurants, supermarkets, travel agents

Advantages of chip and PIN readers

More secure system than contactless payments
More robust system than magnetic stripe cards

Disadvantages of chip and PIN readers

Fraud - need to be careful to ensure PIN is not read by somebody else

Radio frequency identification (RFID) readers

Use radio waves to read and capture information stored on a tag
Tag can be read from a distance of several metres
RFID tag is made up of two components:

- a microchip that stores and processes information

- an antenna used t receive and transmit data/information

Uses of RFID

Livestock tracking
Retail
A big advantage is that several tags can be read at the same time
Admission passes
Tracking of people : height or age
Libraries

Advantages of RFID

Tags can be read from a distance
Very robust and reliable technology
Very fast read-rate
Data transfer allows read and write operations
Detection is possible

Disadvantages of RFID

Tag collision from two or more tags overlap
RFID uses radio waves that are easy to jam or interrupt
Relatively easy to hack into the data/signal transmitted by the tag
RFID is more expensive

Optical mark recognition/reader (OMR)

Uses of OMR devices

Read questionnaires, multiple choice examination papers, voting papers and many other types of form

Advantages of OMR devices

Very fast way of inputting the results
There is no typing, they are more accurate than keying in the data
More accurate than OCR methods

Disadvantages of OMR devices

Need to be carefully designed to make sure marks/shading are correctly positioned
Can be problems if they have not been filled in correctly

Optical character recognition/reader (OCR)

a device that converts the text on hard copy documents into an electronic form
OCR software converts this electronic data into a form that is used in various applications

Uses of OCR

The processing of passports and identity cards
Converting hard copy documents into electronic form
Used in automatic number plate recognition (ANPR) in car parks
Historic newspaper and rare books, preventing damage to the originals

Advantages of OCR

Much faster data entry system
No manual data entry
Number of errors is also reduced

Disadvantages of OCR

The system still has difficulty reading some handwriting
Still not a very accurate technique

Barcode readers

Used to read information in the form of a barcode

Uses of barcode systems

Supermarkets and other shops to give information about the product
Safety function in many companies to ensure that electrical equipment is checked

Advantages of barcode systems

Much faster than keying in data manually and fewer mistakes will be made
Way of recording safety testing of components
Allow automatic stock control
Tried and trusted technology

Disadvantages of barcode systems

Expensive system
Not fool-proof
Easily damaged than RFID tags or magnetic stripes

Quick response (QR) code scanners (readers)

Made up of a matrix of filled-in dark squares on a light background

Uses of QR codes

Advertising to contain data such as business addresses, phone numbers, email addresses and website addresses
Contain links to apps
Wi-Fi authentication used to store Wi-Fi network including passwords and type of encryption
Deliver augmented reality
AR system to determine the positions of objects in three-dimensional space
Establish virtual online stores with a gallery of product information

Advantages of QR codes

Hold much more information than normal barcode
Fewer errors than with barcodes
Easier to read
Not need expensive laser or LED
Easy to transmit QR codes as text messages or images
Encrypt QR codes gives greater protection than traditional barcodes

Output devices and their uses

Monitors

Cathode ray tube (CRT) monitor
LCD or TFT(Thin Film Technology)

CRT (Cathode Ray Tubes) Monitors

Least expensive type of monitor
Becoming increasingly rare as LCD monitors are taking over
Various sizes and make use of an electron gun firing against a phosphor screen
Picture is made up of tiny dots coloured red, green or blue

Uses of CRT monitors

Only used in specialist areas such as computer-aided design (CAD)
Screens are very large to enable complex diagrams to be created or modified
Used with light pens to allow designs

Advantages of CRT monitors

Screen can be clearly seen at a wider range of viewing angles than with most LCD monitors
Allow the use of light pens in CAD/CAM applications

Disadvantages of CRT monitors

Tend to be rather heavy and present a weight hazard
Very large footprint on a desk
Run very hot and can cause fires
Consume considerably more power than LCD monitors
Can flicker which leads to headaches and eyesight problems

LED and LCD screens

LED screens

Is made up of tiny light emitting diodes (LEDs)
Red, green and blue in colour
Brightness can be controlled, producing a vast range of colours
Many monitors and televisions are advertised as lED when in fact they are LCD screens which are backlit using lEDs.

LCD screens

Made up of tiny liquid crystals
Tiny crystals make up an array of pixels affected by changes in applied electric fields
LCD screens to work, require some form of backlighting
Modern LCD screens are backlit using LED technology
When LEDs are used, a matrix of tiny blue-white LEDs is used behind the LCD screen
LED backlighting gives a very good contrast and brightness range.
Before the use of LEDs, LCD screens used cold cathode fluorescent lamps (CCFL)

Advantages of LED screens

Maximum brightness
Whiter light
Produce a brighter light
Screens using LED technology
Thinner than screens using CCFL technology
More reliable
Very little power

Uses of LCD screens

Used as the man output device for most modern computers
LCD screens offer touch-screen input
Mobile phones, tablets, laptops and portable video games all use LCD screens

Advantages of LCD screens

Very efficient
Low power consumption
Lightweight devices
Unlike CRT monitors, do not suffer from screen image burn-in
Screen can be made in large variation of sizes
Do not suffer from a flickering image, unlike CRT monitors
Sharp image resolution
Produce low electromagnetic fields compared to CRT monitors

Disadvantages of LCD screens

Colour and contrast from various viewing angles can be inconsistent
Motion blur is a common issue
Lower contrast than CRT monitors
LCDs can have weak or stuck pixels
LCD panel may not be uniformly illuminated by the back light

Touch screen (as an output device)

Uses of touch screens (acting as both input and output

Smartphones and tablets
ATMs at banks
Ticket collection machines
Information kiosks

Advantages of touch screens

Faster entry of option
Very easy method
User-friendly method
Expand the size of the display if necessary

Disadvantages of touch screens

Limited number of options
Not very good if large amounts of data are being input or output
Screen can get very dirty

Multimedia projectors

Receive signals
Either analogue or digital
Source from a computer, television or DVD player
Image from the source is magnified and projected onto a large screen
Direct the computer presentation
Most multimedia projectors take input from various types of video format

Uses of multimedia projectors

Training presentations
Advertising presentations
Home cinema systems

Advantages of multimedia projectors

Enables many people to see a presentation
Avoids the need for several networked computers

Disadvantages of multimedia projectors

Images can be fuzzy
Expensive to buy
Setting up projectors can be difficult

Printers

Laser printer
Inkjet printer
Dot matrix printer
Graph plotter
3D printer

Laser printers

Produce very high-quality hard copy output
Print per page is very quick if a large number of pages are being printed
Rely on large buffer memories where the data for the whole document is stored before pages can be printed out.

Uses of laser printers

Used where low noise is required
Fast, high-quality, high volume printing

Advantages of laser printers

Printing is fast
Can handle very large print jobs
Quality is consistently high
Toner cartridges last for a long time

Disadvantages of laser printers

Only really fast if several copies are being made
Produce ozone and volatile organic compounds because of their method of printing and type of toner/ink used
Linked to health hazards in the office

Inkjet printers

Used to produce good-quality hard copies

Uses of inkjet printers

Low-output volumes are required
Very good at producing photo-quality printouts

Advantages of inkjet printers

High quality output
Cheaper to buy than laser printers
Very lightweight
Small physical footprint
Do not produce ozone and volatile organic compounds unlike laser printers

Disadvantages of inkjet printers

Slow output if several copies are needed
Cannot do large print jobs
Printing can ‘smudge’ if the user is not careful
Can be expensive if used a lot

Dot matrix printers

Type of impact printer
Print head presses against an inked ribbon
Slow, noisy and the output is not that good compared to inkjet and laser printers
Multipart stationery

Uses of dot matrix printers

Can be used in noisy or dirty environments
Used in applications where multipart stationery

Advantages of dot matrix printers

Used in environments which would be a problem for inkjet or laser printers
Carbon copies or multipart outputs can be produced
Very cheap to run and maintain
Easy to use

Disadvantages of dot matrix printers

Very noisy
Cost more than inkjet printer to buy
Very slow, poor-quality printing

Graph plotters

Use a pen, pencil or marker pen to draw multiple continuous lines
Size of paper can be anything from A4 up to several metres
Produce vector graphic drawings
CAD and CAM

Uses of plotters

Architecture drawings
Engineering drawings
Drawing animation characters

Advantages of plotters

Very high quality output
Produce large, monochrome and colour drawings
Print on a variety of materials

Disadvantages of plotters

Very slow at printing
Expensive
Very large physical footprint compared to a printer

3D printers

Used in computer-aided design(CAD)
Solid object id built up layer by layer using materials such as powdered resin, powdered metal, paper or ceramic

Advantages of 3D printers

Manufacturing of items has become easier than before
Manufacture any product a user wants using only a 3D printer
Medical benefits are emerging
Producing artificial organs, prosthetics and precision-made items for reconstructive surgery

Disadvantages of 3D printers

Potential to make counterfeit items or items that infringe others copyright
Technologies in the hands of the wrong people can lead to dangerous or illegal activities
Technology could be used to manufacture dangerous items by almost anyone
Job losses
Technology takes over from some types of manufacturing

Speakers