ICDL Module 1

Basic Concepts of IT

Content overview Hardware and software Processing and data Types of computer system Networks (an introduction!) Use and misuse of computers in

society

Hardware

Anything you can touch or hit!

InputInput

OutputOutput

Name these peripherals 1

Input or output?

Name these peripherals 2

Input or output?

Software Programs or “applications”

Office “productivity” – Word processor; presentation

Internet – web browsing; email Financial – accounts; payroll Computer records – databases Specialist – computer “control”

Games! Operating system

Operating System Controls CPU and peripherals Creates user “interface”

Normally GUI – Graphical User Interface

eg. Windows XP, Windows Vista MacOS Provides services to other programs

Common user interface Access to memory Data storage on hard disk Printing

Software development

Design

Testing

Systems Analysis

Specification

Programming

Put them in order

3

5

2

1

4

Operation of a computer

Input Process Output

Processing Carried out by CPU (Central Processing

Unit) Calculations – addition, multiplication ...

Logical – Program control, “If… then…”

Control of memory, storage and peripheral devices

Speed measured in Gigahertz (GHz)

Memory and Storage

Main processor

(CPU)

Memory (RAM)

Backing Storage (Disk

drive)

Backup (eg. Tape)

Temporar

Temporar

yyPermanen

Permanen

tt

Types of Memory – RAM

Random Access Memory (RAM) Temporary Programs currently being used Data being processed Open documents, spreadsheets etc. Results etc. saved back to hard disk

Types of Memory – ROM

Read-only Memory (ROM) Permanent “Bootstrap” routine used to start

computer (NB. “Booting up”)

Programs in specialist “embedded” systems eg. Washing machines, mobile phones

Bits and bytes

Bit – single 0 or 1

1 0 0 1 0 1 0 1

Byte – 8 bits – 1 character

Bigger bytes!

Kilobyte (Kb)

Megabyte (Mb)

Gigabyte (Gb)

Terabyte (Tb)

Put them in order of size(smallest first)

1

4

2

3

Bigger bytes 2!

Kilobyte (Kb) – 1024 bytes

Megabyte (Mb) – 1024 Kb

Gigabyte (Gb) – 1024 Mb

Terabyte (Tb) – 1024 Gb

What can you store?

Types of Storage Device

Internal

Hard disk drive – 20 to 250Gb

Computer’s operating system Programs eg. Word, Excel Data – documents, spreadsheets, databases

Temporary files

Types of Storage Device

Devices with removable media:

Floppy disk – 1.44Mb

500+ page document, several photos

CD – 740Mb. Many photos; large program suite

DVD – 4,700Mb/4.7Gb. Full-length film

ZIP disk – 100 or 200Mb. Used mainly for backup

Tape (DAT) – 5 to 250Gb. Backup of hard drives

Types of computer system Handheld

Mainframes

PCs and laptops

3

1

2

Put them in order of size(largest first)

Handheld PDAs (Personal Digital

Assistant) and Organisers Highly portable Cheap ($150-$800)

Diary, address book, notes, phone numbers

Cut-down versions of PC applications

PCs and Laptops (or Notebooks)

PC = Personal Computer Mainstay of computer

“workforce” Relatively cheap ($1000-

$2,500) May be standalone or

networked (as terminals) Fully portable PCs are

called laptops (or notebooks) – more expensive ($1200-$3,500)

Mainframes

Centre of large network Multiple processors and huge storage Very large or complex systems Very expensive ($200,000+)

Networks LANs – Local Area Networks WANs – Wide Area Networks

Intranet Extranet

LANs Local! Connecting an office or within a

building Wires or radio connections Central server controls access and

data Also called Intranet

A simple LAN

What are the parts?Switc

h

Server

Clients

Wireless

router

WANs Connecting multiple buildings or

sites Leased line and broadband links Multiple connected servers and

LANs The Internet is a public WAN

Connecting to the Internet What do you need to connect?

Your computer

The Internet

Phone line

Modem

ISP

Internet Service Provider

Internet and Bandwidth

Narrowband PSDN – Public Switched Data Network

Slow (less than 56Kbps) Fax machines

ADSL – Asynchronous Data Subscriber Line Much Faster Uses PSDN lines

11001

Faster Internet Connections

1

00

11

100

1 10

00

01

11 0

1 1

Broadband – “fat pipes” ADSL and cable modems Leased lines Faster speeds (512Kbps-

10Mbps)

Bandwidth – “speed”

Megabit per second (Mbps)

Kilobit per second (Kbps)

Bit per second (bps)

Gigabit per second (Gbps)

Put them in order of speed(slowest first)

3

2

1

4

Using the Internet Web browsing – Internet Explorer,

Netscape Email – Hotmail, Outlook Express, Eudora Chat – MSN Messenger Newsgroups Blogs and podcasts Complete services – AOL; MSN

Use of computers in society

Typical uses in (for example): Small businesses – letters, mailings, budgeting

Hospitals – medical records, specialist equipment

Education – assessment records, attendance

Libraries – lending records, “overdue” letters Shops – Electronic Point of Sale (EPOS) terminals

Home – Internet, games

Misuse of computers Hacking & viruses Copyright Security and passwords Processing data fairly and lawfully Data Protection Act 1998 Computer Misuse Act 1990

Health and Safety Use of screen (most important first):

Regular breaks (10 minutes after 1 hour)

location of equipment Eye exercises

Seating and posture Repetitive Strain Injury (RSI) Cables and electrical equipment