ICT Chapter 2 - Input, Output & Storage Device

Common layout of a keyboard

QWERTY

Ergonomic

Use

• input data into application (eg: text into Pages)

• typing in command to the computer (eg: shortcut key)

Advantages:

• fast entry of new text into a document
• easy to use for most people
• easier to do verification checks as the data is entered

Disadvantages:

• can be difficult to use if the user has limited arm/ wrist use
• slow method of compared to direct data entry
• fairly large device that uses up valuable desk space

Concept Keyboard

• uses icons or phrases instead of standard letters

• often used in fast-food restaurants, when a single key represent one item

Advantages:

• fast data entry (no need to type the whole command)
• usually waterproof & tamper resistant

Disadvantages:

• limited function
• changes in program lead to changes in keyboard

Numeric Keypad

• used to enter numbers only

Uses

• ATM - where customer keyin their PIN number

• Point-of-Sale (POS) terminal - incase barcode reader fails to read the barcode

• CHIP and PIN device - paying by debit card

• Normal keyboard - for fast entry

Advantages:

• Faster than standard keyboards when entering numeric data
• very easy to carry around because usually its small

Disadvantages

• sometimes have small keys which can make input more difficult
• sometimes the order of the numbers on the keypad isn't intuitive

Mouse

• can double click, right click, left click
• have scroll button

Advantages

• faster way to choose an option than using a keyboard
• very quick way to navigate through application and the internet
• doesn't need a large desk area when compared to a keyboard

Disadvantages

• more difficult for people with restricted hand/wrist movement than using keyboard
• easy to damage
• difficult to use if no flat surface is readily available

Touchpad

• use in many laptop computers
• controlled by moving a finger and gently tapping
• have button which serve as left and right click

Advantages

• Same as the mouse
• since it is integrated into the laptop, there is no need for a seperate mouse

Disadvantages

• People with limited hand movement find the device difficult to use
• can be more difficult to control the pointer when compared to a mouse
• more difficult to use when doing certain operations such as drag and drop

Trackerball

• control the pointer by rotating the ball
• for people with limited hand movement

Advantages

• Doesn't need the same fine control as a mouse
• Easier to use if the operator is disabled
• More accurate positioning of the pointer on screen
• More robust
• needs less desk space

Disadvantages

• Not supplied with computer standard
• costly
• need training

Digital Camera

• directly reading the memory card by slotting it into computer or to the printer
• connect using USB
• using wireless transfer

Advantages

• Easier to produce better quality image
• faster to upload image than scanning hard copies
• No need to develop film and print out
• memory card can store several hundred images

Disadvantages

• Need to be computer literate
• Images are often need to be compressed to reduce the amount of memory used

Video Camera

• Similar with digital camera but specialised more to take a video

Magnetic Stripe

Contactless

Chip

&

PIN

Magnetic Ink Character Recognition / Reader (MICR)

• read characters printed in a special ink (containing iron particles)
• Only certain characters written in a standard font can be read

Uses

• primarily used to process cheques in banking operations

Advantages

• Greater security - printed characters cant be altered
• no manual input - reduc errors
• readeable

Disadvantages

• characters are limited
• expensive

Optical Mark Recognition/ Reader (OMR)

• device that can read marks written in pen or pencil
• numerical lozenge us shaded and the position of the mark is stored in the computer's memory

Uses

• read questionnaire, multiple choice exam papers

Advantages

• very fast inputting the results of surveys, etc
• more accurate - no typing

Disadvantages

• forms need to be carefully designed to make sure that the marks. shading are correctly positioned
• problem occured if the forms havent been filled in correctly

Optical Character Recognition/ Reader (OCR)

• device that scan text and converts it into computer-readable form

Uses

• Processing passports and identity cards

Advatages

• faster than manually data entry
• reduce error

Disadvantages

• difficult to read handwriting
• not very accurate - various fonts

Radio Frequency Identification (RFID) Readers

• use radio waves to read and capture information stored on a tag
• the tag can be read from a distance of several metres
• two components:
• microchip - store & process information
• antenna - receive & transmit data
• Two types:
• passive - use the reader's radio wave energy
• battery-powered - small & embedded

Uses

• livestock tracking (animal location)
• retail (similar to barcode but do not need scanning)
• admission passes (tolls)
• libraries/ shop (prevent unauthorised checkout)

Advantages

• no line-of-sight contact is necessary
• can be read from distance
• robust & reliable
• fast read rate
• bidirectional data transfer
• bulk detection is possible

Disadvantages

• tag collision (two or more tags overlap)
• Easy to jam or interrupt
• relatively easy to hack
• more expansive than barcode

Barcode Readers

• read information in the form of a barcode
• handheld scanners or wands
• often built into POS terminals

Uses

• in supermarkets/ shops where the goods are marked with a barcode (store information about the product which enables stock control, itemised billing etc)
• libraries - to keep track of books
• safety function in many companies to ensure equipment records

Advantages

• much faster than keying in data manually
• improve data safety
• allow automatic stock control
• proven as trusted technology

Disadvantages

• relatively expensive system
• not foolproof (barcodes can be swapped around on items)
• can be more easily damaged than RFID tags or magnetic strips

Near Field Communication (NFC)

• based on RFID technology but in shorter range
• need direct line of sight to reader
• only single NFC can be scanned at one time

Quick Respond (QR) Scanner

• quickly scan quick response code and convert them to string of characters
• widely used for website addresses and product identifier
• can store more information (7000 characters) than to barcode (30 char)

Advantages

• no need the user to write down the website address
• can be scanned anywhere using phone - a very effective method of advertising
• can store more information

Cathode Ray Tube (CRT) Monitor

• old, bulky & heavy
• least expensive
• becoming rare
• produce image made up of tiny dots (red, green & blue)

Advantages

• screen angle is better than TFT
• cheaper
• produce large range of colour than TFT
• can be used with light pens

Disadvantages

• large, bulky and heavy
• take up desk space
• create a lot of heat
• screen glare when in direct light makes viewing difficult
• prone to screen flickers
• need more power than TFT

Thin Film Transistor (TFT) Monitor

• Flat screen monitor
• made up of thousands of tiny pixels
• each pixels - 3 transistor (red, blue & green)
• a backlight is used to shine light onto these pixels

Advantages

• thin and lightweight
• take up less space
• produce less glare
• use less power
• produce less radiation
• produce less heat

Disadvantages

• image can appear unclear when viewed from different angle
• lower picture quality

Liquid Crytsal Display (LCD) Monitor

• use TFT technology
• front layer made using LCD diodes
• use cold cathode fluorescent lamp (CCFL) as backlighting

Light Emitting Diode (LED) Monitor

• matrix of tiny LED
• more expensive
• sharper image
• improved colour definitions

Laser Printer

• high quality hard copy output
• toner pressed on the page
• print large amount very quickly
• use buffer memory (store information before printing out)
• use laser beam to draw
• spray over the drum
• drum is pressed onto a sheet of paper

Advantages

• fast printing
• toner catridge last longer
• handle high volume of printing
• very quite
• high quality printouts
• cheaper to run (low cost per page)

Disadvantages

• environmental unfriendly (produce ozone)
• machine is more expensive
• large in size

How laser printer works

Inkjet Printer

• good quality hard copy output
• spraying ink onto a paper
• use ink catridge (black, cyan, magenta, yellow)
• small amount of internal memory
• motor are used to position the ink

Advantages

• good quality (often used for printing photograph)
• machine is cheaper
• smaller
• dont produce ozone

Disadvantages

• slow printing rates
• ink catridge finish quickly
• expensive to run
• easily smudge the document

How inkjet printer works

Dot Matrix Printer

• type of impact printer
• print head is made up of a matrix of pins
• pressed again an inked ribbon

Uses

• used in noisy environment
• used when print quality is not important
• use in application where multipart & continuous stationary is used

Advantages

• can be used in environments that would be a problem to laser & inkjet printers
• carbon-copies or multipart output can be produced
• cheap to run & maintain
• easy to use if continuous stationery is required

Disadvantages

• very noisy
• cost more than inkjet printer to buy initially
• very slow, poor quality printing
• the ink on the printouts tend to fade over time

3D Printers

• can produce solid object that actually work
• the solid object is build up layer by layer
• using material such as resin, metal, paper or ceramic

Uses

• prosthetic limbs
• making items to allow precision reconstructive surgery
• making parts
• fashion & arts

How 3D printer works

Motors

• in automatic washing machine - to rotate the drum
• water pumps
• fan
• open windows & doors automatically
• in computers - rotating the DC/ DVD

Buzzers

• in cookers or microwaves to tell cooking process is complete
• burglar alarm system

Heaters

• control the temperature in a hotplate or oven
• control the heating in a central heating system

Lights

• security lights
• automatic lights

Fixed Hard Disk Drive (HDD)

• uses on all computers
• main method to store data
• fast access
• large capacities
• surface (platter) is coated with magnetic film

Uses

• store operating system and application software

• store files and documents

Advantages

• fast read/ write times
• huge capacities
• easy to update/ delete files

Disadvantages

• damaged easily when computer is not shut down properly

• not portable

Portable Hard Disk Drive (HDD)

• similar to fixed HDD
• connected externally using USB
• transportable
• protective casing to avoid physical damage

Uses

• similar to Fixed HDD
• portable back up system
• transfer data, files and software

Advantages

• fast read/ write
• huge capacities
• small and light
• plug into almost any computer

Disadvantages

• easy to misplace/ stolen
• more expensive
• easily damage if its dropped

How it works?

• store data as a number of dots that can be read using a light

• each dots represent 1's and 0's (binary data)

• read data: laser beam reflections that hits the dot
• write data: laser beam to burn a dots

CD-ROM & DVD-ROM

• CD = compact disc
• DVD = Digital Versatile Disc
• ROM = Read Only Memory
• bought with preloaded data (software, musics, games, movies
• data cannot be deleted/ changed

Advantages

• hold more data than floppy disc
• less expensive
• cannot accidentally erased data
• very portable

Disadvantages

• less data than HDD
• slow read times
• cannot add more files

CD-R & DVD-R

• R = recordable once
• after data has been write, it becomes ROM
• data can be added but not erased

Uses

• personalised playlist
• backup important data
• transfer data

Advantages

• can write own data
• cannot accidentally delete
• cheaper than RW and HDD
• easy to transport
• similar to ROM

Disadvantages

• only recordable once
• if error during burning, disc is damaged
• very slow read/ write
• not all CD/DVD players can read CD/DVD-R

CD-RW & DVD-RW

• RW = Re-Writable
• can be recorded over and over
• used phase changing dye - allow dots to be undone

Advantages

• can be re-used many times
• data can be updated
• not a waste

Disadvantages

• more expensive than CD/DVD-R
• accidentally overwrite existing data
• read/ write slower than HDD

DVD-RAM

• write/ read can happen at the same time
• similar to RW but faster, last longer and more reliable
• usually used for DVD recorders and camcorders

Advantages

• long last
• can be written over 100 thousands times (RW usually around 1 thousand)
• very fast read/ write times
• very large capacities
• can write and read at the same time

Disadvantages

• expensive
• needs specific devices to works

Blu-ray Disc

• similar to RW
• used blue colour laser
• allow dots to be position closer
• result in more data dots and higher capacities

Solid State Hard Drives (SSD)

• no moving part
• store data as 1's and 0's within millions of electrical transistors

Advantages

• longer life span
• run silently
• faster data access & transfer time
• use less power
• produce less heat

Disadvantages

• smaller storage capacity
• More expensive

Pen Drive/ Memory Stick

• small & portable
• easily transfer

Advantages

• small & lightweight
• robust
• compatible with almost all computer
• large storage capacities

Disadvantages

• easily copy over data
• easily misplace or lose
• more expensive per GB than magnetic hard disc

Flash Memory Card

• a.k.a. Secure Digital Card (SD Card)
• used in handheld devices (mobile phone, camera, mp3 player)

Advantages

• very small & easy to transport
• robust
• easy to connect

Disadvantages

• more expensive per GB than magnetic HD
• lower storage capacity
• easily stoled or lose
• Desktop & Laptop dont usually come with SD card reader

Solid State Hard Drives (SSD)

• no moving part
• store data as 1's and 0's within millions of electrical transistors

Advantages

• longer life span
• run silently
• faster data access & transfer time
• use less power
• produce less heat

Disadvantages

• smaller storage capacity
• More expensive

Pen Drive/ Memory Stick

• small & portable
• easily transfer

Advantages

• small & lightweight
• robust
• compatible with almost all computer
• large storage capacities

Disadvantages

• easily copy over data
• easily misplace or lose
• more expensive per GB than magnetic hard disc

Flash Memory Card

• a.k.a. Secure Digital Card (SD Card)
• used in handheld devices (mobile phone, camera, mp3 player)

Advantages

• very small & easy to transport
• robust
• easy to connect

Disadvantages

• more expensive per GB than magnetic HD
• lower storage capacity
• easily stoled or lose
• Desktop & Laptop dont usually come with SD card reader