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!

Input

Output

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; 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

Operation of a computer InputProcessOutput

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) Temporary Permanent

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 Byte – 8 bits – 1 character

Bigger bytes! Kilobyte (Kb) Megabyte (Mb) Gigabyte (Gb) Terabyte (Tb) Put them in order of size (smallest first)

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 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? Switch 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 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)

Using the Internet Web browsing – Internet Explorer, Netscape – 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