icdl module 1 basic concepts of it content overview hardware and software processing and data types...
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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