User must know

1. Know the 3 basic operations of a computer

2. Identify the different parts of a computer

3. Connect the different parts of a desktop computer

4. Distinguish between hardware and software

2.1 The Basic Operations of a Computer

• A program consists of step-by-step instructions telling the computer what to do and how to do it

• Without instructions, computers cannot do anything

2.1 The Basic Operations of a Computer

• People need instructions to do something too

2.1 The Basic Operations of a Computer• Do people and computers carry out a

task in similar ways?• Compare how people and computers

divide 2,760 by 4

2.1 The Basic Operations of a Computer

• Both people and computers do the following:

2.1 The Basic Operations of a Computer

2.2 Parts of a Computer• A computer is made up of different

parts• Each part performs different function or

operation

2.2 Parts of a Computer

• The casing of the system unit• Commonly called

Central Processing Unit (“CPU”)

• Contains a processor

2.2 Parts of a Computer• The casing of the system unit (Cont’d)

• Comes in a variety of design

2.2 Parts of a Computer• The keyboard and mouse

• Important tools because they are used to control the computer

• Designs have improved greatly

2.2 Parts of a Computer• The display unit

• Displays information onto a screen• Main way computer communicates with

users• Many types invented over the years

2.2 Parts of a Computer• Printers

• Prints text or illustrations onto paper• Main types:

• Thermal printer• Print created by

pushing heated pins against heat sensitive paper

• Cheap and fast• Used widely in

supermarket checkouts and ATM

2.2 Parts of a Computer• Printers (Cont’d)

• Inkjet printer• Print created by

spraying dots of ink onto paper

• High quality text and graphics

• Slow• Cost of printer low

but cost of ink is high

2.2 Parts of a Computer• Printers (Cont’d)

• Laser printer• Print created by

• Applying ink powder (toner) to drum

• Toner on drum is then heated and applied to paper

• Very high quality text and graphics

• Fast• Expensive• Toner is sold in cartridges

• Expensive but can print more pages than an inkjet printer

2.2 Parts of a Computer• Printers (Cont’d)

2.3 Software and Hardware

1.Inkjet2.Laser3.Dot matrix4.Laser

2.2 Parts of a Computer• Printers (Cont’d)• Multifunctional printers

• Multiple functions• Printing, copying

and faxing• Convenient• Disadvantages

• Over-using one function may interfere with other functions

• More likely to break down due to the many functions

2.2 Parts of a Computer• Wired and wireless computer parts

• Computer parts classified into wired and wireless ones

• Wired computer parts• Physically connected by wires or cables• Connected to attachments called ports

2.2 Parts of a Computer• Wired and wireless computer parts

• Wireless computer parts• No physical

connection• Example: wireless

router, cordless mouse

2.3 Software and Hardware• Computers need hardware and software to work• Hardware

• Physical• Can see and touch

• Software• Data and instructions for the hardware to operate

2.3 Software and Hardware

1. Hard disk, keyboard, LCD monitor, mouse, printer2. (Any 5 examples)– Operating system: Microsoft Windows, Linux, Mac

OS etc.– Application program: Adobe Photoshop, Microsoft

Word, Warcraft, Internet Explorer, Macromedia Dreamweaver

2.4 Input, Output and Storage Devices

2.4 Input, Output and Storage Devices

• All these are input devices

• Scanner• Scans

information on hard copy into the computer

• Microphone• Captures sound

into the computer

2.4 Input, Output and Storage Devices

• CPU• Contains the central processor

• “Brain” of the computer• Processes data and

instructions• Hard disk

• Stores data• Hard drive

• Helps store and retrieve data

• Floppy disk drive• Reads and writes data on

floppy disks• CD-ROM drive

• Reads data from CD-ROMs

2.4 Input, Output and Storage Devices

• CPU (Cont’d)• Thumb drive

• Also called USB flash drive• Reads and writes data onto

the drive’s memory chips• Main memory

• Stores data and programs to be used by the main processor

• Includes• Read Only Memory

(“ROM”)• Stores data

permanently• Random Access Memory

(“RAM”)• Stores data

temporarily

2.4 Input, Output and Storage Devices

• All these are output devices• Monitor

• Like a television screen• Displays information from the

data inputted• Printers

• Display information on paper• Hard copy

• Some prints in colour; others print in black only

• Speakers• Produces sound and music

generated by the computer

1. Keyboard, mouse, flat-bed scanner, microphone

2. Monitor, speaker, laser printer, inkjet printer (Other answers: projector)

3. CD-ROM drive, hard disk (Other answers: thumb drive)

2.4 Input, Output and Storage Devices