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Published byRichard Norman Modified over 9 years ago
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ICDL Module 1 Basic Concepts of IT
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Content overview Hardware and software Processing and data Types of computer system Networks (an introduction!) Use and misuse of computers in society
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Hardware Anything you can touch or hit!
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Input
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Output
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Name these peripherals 1 Input or output?
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Name these peripherals 2 Input or output?
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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
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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
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Software development Design Testing Systems Analysis Specification Programming Put them in order 3 5 2 1 4
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Operation of a computer InputProcessOutput
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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)
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Memory and Storage Main processor (CPU) Memory (RAM) Backing Storage (Disk drive) Backup (eg. Tape) Temporary Permanent
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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
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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
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Bits and bytes Bit – single 0 or 1 1 0 0 1 0 1 0 1 Byte – 8 bits – 1 character
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Bigger bytes! Kilobyte (Kb) Megabyte (Mb) Gigabyte (Gb) Terabyte (Tb) Put them in order of size (smallest first) 1 4 2 3
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Bigger bytes 2! Kilobyte (Kb) – 1024 bytes Megabyte (Mb) – 1024 Kb Gigabyte (Gb) – 1024 Mb Terabyte (Tb) – 1024 Gb What can you store?
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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
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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
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Types of computer system Handheld Mainframes PCs and laptops 3 1 2 Put them in order of size (largest first)
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Handheld PDAs (Personal Digital Assistant) and Organisers Highly portable Cheap ($150-$800) Diary, address book, notes, phone numbers Cut-down versions of PC applications
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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)
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Mainframes Centre of large network Multiple processors and huge storage Very large or complex systems Very expensive ($200,000+)
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Networks LANs – Local Area Networks WANs – Wide Area Networks Intranet Extranet
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LANs Local! Connecting an office or within a building Wires or radio connections Central server controls access and data Also called Intranet
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A simple LAN What are the parts? Switch Server Clients Wireless router
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WANs Connecting multiple buildings or sites Leased line and broadband links Multiple connected servers and LANs The Internet is a public WAN
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Connecting to the Internet What do you need to connect? Your computer The Internet Phone line Modem ISP Internet Service Provider
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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
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Faster Internet Connections 1 0 0 1 1 1 0 0 1 1 0 0 0 0 1 1 10 11 Broadband – “fat pipes” ADSL and cable modems Leased lines Faster speeds (512Kbps-10Mbps)
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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
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Using the Internet Web browsing – Internet Explorer, Netscape Email – Hotmail, Outlook Express, Eudora Chat – MSN Messenger Newsgroups Blogs and podcasts Complete services – AOL; MSN
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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
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Misuse of computers Hacking & viruses Copyright Security and passwords Processing data fairly and lawfully Data Protection Act 1998 Computer Misuse Act 1990
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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
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