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European Computer Driving Licence

Module 1 – Concepts of IT

Section 1: General Concepts

This presentation is an open source material on web, some modification made by: Sumayah Abu-Dawood

The original source found on: http://www.pearsonschoolsandfecolleges.co.uk/FEAndVocational/ITAndOfficeTechnology/ECDL/PGECDL/FreeResources

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General ConceptsZ Information Technology (IT)

, General term used to describe the use of computers to process and transfer information.

, Can also refer to other office equipment (such as faxes and telephones) which contain tiny computers

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Hardware and Software

Z Hardware (HW), Refers to the physical

parts of a computer – those parts which you can see or touch.

Z Software (SW), Primarily a list of instructions coded in

a special way that computers can understand.

• Operating system software – e.g. Windows which works in the background and controls your software and hardware devices

• Applications software – e.g. Microsoft Word – software used to perform tasks

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main parts of computer system

Z Monitor (VDU) visual Display Unit: to display results of processing.

Z System Unit : this contains all the basic computer components that do all the hard work

Z Keyboard: to enable text and commands to be input into the computer

Z Mouse: to enable the user to point and click at pictures and menus

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Different Types Of Computer

Z Personal Computers (PC).Z Laptop/Notebook Computers.Z Mainframe Computers.Z Networked Computers.Z Personal Digital Assistants (PDA )/ Handheld Computers.

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Personal Computers (PC)

Z An essential tool for managers, humble office workers and home usersZ Two main types:

, Desktop model – the system unit sits horizontally on a desk and the monitor is placed on top

, Tower model – the system unit is vertical so can be placed on the floor to save desk space

Z Hardware devices (screen, keyboard and mouse) attached to the system unit (by a cable) are called peripheral devices

DesktopTower

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Notebook/Laptop Computers

Z Similar in specification to a personal computerZ Monitor and keyboard are integrated into a single unitZ Can be used from the mains or with a built-in rechargeable battery

Z More expensive than personal computers due to miniaturisation of computer components

Z Ideal computer for business people and ICT trainers who are constantly on the move

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Mainframe ComputersZ Large, fast and expensiveZ Used by large organisations

such as utility companies, banks or multinational companies.

Z Connect hundreds or thousands of users.

Z Users connect via terminals which are located in different cities or even abroad., Dumb terminals – these types

of terminals cannot be used unless they are connected to the mainframe

, Intelligent terminals – e.g. a personal computer connected to a mainframe, can also be used when not connected to the mainframe

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Mainframe Computers

Mainframe

London

Dublin Paris

New York

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Networked Computers

Z Personal computers can operate as stand alone computers or they can be connected together as networked computer.

Z Many networks use a server , which is a computer that controls access to HW, SW and other resources on a network.

Z Personal computers connected to a server via network cards and cables

Z The software and data is stored on the central server rather than installed individually on each PC

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Networked Computers

Server

Z The network also enables a fast Internet connection, printers and scanners to be shared.

Z Users access allocated resources via a user name and password.

Z Very popular with small-to-medium-sized businesses, schools and colleges/adult education centres.

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PDAs/Handheld ComputersZ Handheld computer is a

computer small enough to fit in one hand.

Z Some use a stylus which you use to write or draw on the screen.

Z Run very basic cut-down software such as calculator, address book and notepad functions

Z Can be connected to a PC to synchronise data.

Z PDAs can also be used as mobile phones and can access the Web to send and receive emails.

stylus

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Computer Components

Computer

HardwareAny physical part that you can see and touch.

SoftwarePrograms that allow you to use computer but you

can not see or touch.

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Hardware ComponentsComputer

Hardware

CPU

Memory

Storage Devices

Input Unit

Output Unit

Software

Operating System

Application

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Central Processing Unit (CPU)Z The main brain of the computer that

performs the work and controls the transfer of information.

Z The speed at which CPU can process information is known as clock speed.

Z Speed is measured in Megahertz or Gigahertz., Megahertz (MHz)= 10 6 (1 million cycle per

second)., Gigahertz (GHz): 10 9 (1 billion cycle per

second).

Z When CPU is on one chip, this is a microprocessor.

Z Examples: Intel, AMD.

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Computer Memory

Z RAM (Random Access Memory):, Store information temporary., CPU transfers information from the

hard disk drive to RAM., The more you have installed, the

faster your computer will work., When the computer is switched off,

anything stored in RAM is lost

, Volatile memory

Z ROM (Read Only Memory):, Store information permanently ., Used to store important information that

the CPU needs to keep the PC running., ROM can only be accessed by the CPU

and cannot be changed. , The information doesn't lose its content

when power is switched off., Information stored in ROM can be used

repeatedly

, Nonvolatile memory.

Memory is a chip that holds data waiting to be processed & instruction waiting to be executed.

There are two kinds of memory:

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Computer Memory

RAMMain memoryVolatile memory

ROMSecondary memorynonVolatile memory

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How RAM is work???

Z Switch on the computer, The processor transfers

operating system software from the hard disk drive to RAM.

, The Windows desktop appears.

Z Double-click on the Word icon., The processor transfers

the software from the hard disk drive to RAM.

Z Open a Word document, The processor transfers

the file information into RAM so you can see it and make changes to it.

Z If you don’t SAVE the document, the changes will be lost when you switch off the computer!

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How ROM is work???

Z Switch on your computer.Z (POST) and boot-up are carried out to make sure your CPU,

memory chips and other components are working:, If they are, then information is transferred to RAM to start up your

operating software.

, If not, then an error message will appear on screen.

Z The PC start-up software is stored in ROM so it can be used time and time again.

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How memory is measured

Z RAM is divided into millions of units called Bytes.Z Each byte contains 8 bits, which represent s one character (A,@,6,....).Z Memory sizes :It’s the number of bytes the chip or devices has

available for storageZ 1 kilobyte (KB) =1024 bytes Z 1 megabyte (MB) =1024 KB Z 1 gigabyte (GB) =1024 MBZ 1 terabyte (TB) =1024 GB

0 0 1 1 0 1 0 0E

:::

One BYTE

RAM

8 bits represent (4)

byte

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File Sizes

Z A simple Word document will measure approx 20Kb

Z A 12 page report with pictures will take up much more space – maybe 300Kb

Z A 100 page user manual with photos and screenshots could be at least 2Mb in size

Z Microsoft Excel, for example, takes up approx. 6Mb of hard disk space

0

1000

2000

3000

4000

5000

6000

Textdocument

12 pagereport

100 pagemanual

MicrosoftExcel

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Input devices

Z These are devices used to put data into the computer

Keyboard Light pen

Mouse Scanner(OCR)

Trackball Joystick

Microphone(Voice Recognition)

Digital camera

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Output Devices Monitors (VDU)

Z Come in 15”, 17”, 19”, 21” screen sizes., Picture is made up of

millions of dots called pixels, Picture quality depends on

number of pixels going across and down the screen

Z Resolutions, Resolution is the number of

horizontal and vertical pixels in a display device.

, 800 x 600 is typical of a 15” screen

, 1600 x 1200 is typical of larger screens

Z Two different types, CRT monitors – similar to a

TV screen, TFT monitors – much more

slim line

CRTTFT

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Monitors

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Monitors

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Output Devices - Printers

Z Inkjet printers, Mainly used by home users, Black and white or colour printing, Medium in quality and cost.

Z Laser printers, Used in most offices., Black and white or colour print, High price but suitable for large number of prints.

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Output Devices - Printers

Z Dot matrix printers, Very noisy and low print quality., Low cost , use to print invoice, schedule, appointments.

Z Plotter, Used mainly by architects to produce high quality prints such as: building

plans, posters.

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Output Devices

Z Speakers:, Connect to a soundcard supplied with multimedia PCs that acts as

(stereo)., Speech synthesiser: program is able to transfer written text into audible

speech.

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Input/Output Devices

Z Touch screen, Allows the user to touch an area of the screen rather than typing from a

keyboard, Used mainly in tourist offices, bus information kiosks and Job Centres

Z Modem, Use to transfer telephone signal to digital or vs..

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Storage Devices

Z Is the physical material on which a computer keeps data, instructions and information.

Z There are 2 types of devices storage :

- Magnetic Disks :Use magnetic particles to store items on a disk’s surface. Three type of magnetic disks are Hard disks ,Floppy disks and Zip disks

- Optical Disks- Optical discs store items by

using microscopic pits ( indentations) and lands (flat areas) that are in the middle layer of the disc.

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Storage Devices

Z Hard disk drive HDD– this stores all your programs and data.

Z HDD stores huge amount of data, the capacity is measured by GB, the speed of HDD is called access time.

Access time is the time required by HDD to search and retrieve data.

Access time is measured by millisecond (msec)

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Other Storage Devices

Z Floppy disk drive – this stores smaller files.

Z Zip Drive, Uses zip disks which can store

either 100Mb or 250Mb of data, Can be internal or can plug into

a PC’s USB port

Z Flash Drives, Plug into a USB port, Typical storage – 28Mb, 256Mb,

512Mb,1GB-32GB.

Zip Drive Floppy Disk

Flash memory

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Note

Z Data is saved as magnetized dots on Magnetic storage medium.

Z Storage surfaces is divided into : Track an Sector.

Z Formatting: the process of preparing storage disk for use, it creates Tracks and Sectors.

Z When you format your disk, all data is erased and the disk will be as “ anew” one.

Track Sector

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Storage Devices

Z There are many different formats of optical discs exist today. CDs and DVDs

Z DVDs having a much greater storage capacity than CDs.

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Storage Devices

, CD –ROM : software and games are normally supplied on CD ROM disks. Information is read-only and cannot be changed.

capacity : 650MB (75 min of music).

, CR-R (Recordable): user can store data once .

, CD-RW (Re-Writable): allow user to save data many times.

, DVD ROM drive – these can be used to watch films etc.

, DVD-R (Recordable): used to save data once.

capacity: 4.7GB (120 min video).

CD-

ROM

CD-

R

CD-

RW

DVD

DVD-

R

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The System UnitZ System Unit is a case that

contains electronic components of the computer

Z It can be a tower case or desktop case.

Z The main circuit board of the system unit is the motherboard.

Z motherboard contains complex electronic circuits and silicon chips.

Z All the computer components plug into the motherboard either directly into slots or by cables.

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The System Unit

CD-ROM Drive:Read information and write on CD, read from DVD.

Floppy disk drive:Read and write information From floppy disk.

On/ Offswitch

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The System Unit

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Removable Storage Comparison

Device Capacity

Floppy disk 1.44Mb

Zip 250Mb

Flash drives 256Mb

CD 650Mb

DVD 4.7Gb

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Computer Performance

, The clock speed of the CPU (measured in MHz, GHz).

, The capacity of RAM installed (measured in MB, GB).

, The capacity and speed of HDD (Hard Disk Drive).

, The number of application running.

Four main factors will determine the Performance of computer:

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Software Components

Computer

Hardware

CPU

Memory

Storage Devices

Input Unit

Output Unit

Software

Operating System

Application

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Operating System (OS)

Z OS: A special computer programs that organise and control a computer., Provides an interface so that the user can communicate with the computer., Communicates between software and hardware devices., Organises the storage and retrieval of information.

, Manages the smooth running of programs running in RAM by allocating the required resources.

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The BIOS (Basic Input/Output System)

Z The most basic software within the PC.Z Stored in ROM.Z Ensures the hardware operates properly.Z Records basic information about the PC.Z Usually configured by the manufacturer.Z No user intervention is usually required.

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Example of Operating Systems

Z Microsoft Windows: Windows95, Windows Me, Windows XP, Windows Vista.

Z MS-DOS created by Windows but text-based

Z Macintosh (MacOS) was created by Apple.

Z Linux is a popular alternative open-source OS.

Z Unix is another OS used in companies or universities.

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User interface

Z You interact with software through its user interface.

Z The user interface controls how you enter data and instructions and how information is displayed on the screen.

Z 2 types of user interfaces are , Command-line interfaces., Graphical user interfaces

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Command-line interfaces

Z User types commands or presses special keys on the keyboard to enter data and instruction.

Z Its difficult to use because they require exact spelling, grammar and punctuation

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Graphical User Interface (GUI)

Z Enables users to click and point at icons and menus on screen, instead of typing in computer commands

Icon

Menu

Keeping Up to date

Service packs:

Z A collection of updates, fixed for your operating system.Z It contains new drivers for many computer components. Z Could be supplied on a CD or downloadable from the

internet.

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What happens when computer boots up??

Z When computer is switched on, BIOS carries out (POST) – Power On Self Test and do boot-up operation.

Z Boot-up operation has 2 main functions:, Ensure that all hardware is running ,CPU and memory are

functioning correctly., Load the operating system (OS) from HDD to RAM.

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Application Software

Z Application software: is a computer programs designed for a specific purpose.

Z Application software is separate from the operating system but must be compatible with it in order to be able to operate.

Z Each application software is suited for special purpose…. See following example.

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Examples of Application SoftwareUse Example Application

Format text, write letter Microsoft Word Word Processor

Organize numbers in tables and do calculations

Microsoft Excel Spreadsheet

Stores large data that can be questioned

Microsoft Access Database

Design presentation with text, image, sound, video.

Microsoft PowerPoint Presentation Tools

Design large pager like poster and catalog

Microsoft Publisher Desktop Publishing

View and organize email Microsoft Outlook Express E-mail

Access information on the internet.

Microsoft Internet Explorer Web browsing

Design graphics Photoshop/ CorelDraw Graphics51

Did you see this message???

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Problem Solving

Problem reason

Hardware

No printout

Software

Application not respond

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Common error indicators

Z No display on the screen.

Z Error messages on screen.

Z Flashing lights on printer.

Z No printer output.

Z No mouse cursor.

Z Bleeping sounds from system unit.

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Resolving problems

Z Basic checks:, Power supplies, External connections, Supplies of consumables

Z Manufacturer support

Z Manuals

Z Windows Help and Support Centre

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Other considerations

Z Error reporting

Z Automatic System Updates

Z Device drivers

Z Backups

System Development

Analysis •Perform by “system analysts”.•Meet Project members, set objectives, write specifications.

Programming •Perform by “programmers”.•Write the program using programming language.

Testing •Perform though development to correct system “bugs” and faults.•Next test performs by users who can use the system (Beta testing).

Documentation •Written the finished system.•2 levels: technical operation for future development, user guides.

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System development cycle is a set of activities used to build an information system.