la2 computer system

LA 2: Computer System 2013

Panitia ICT SMK Perlis

Example of Input Device Keyboard Touchscreen CCTV Bar code reader Scanner Web cam Microphone joystick Mouse Digital camera Laser pen

Example of Processor

CPU (Central Processing Unit)

Example of Output Device

Monitor Speaker Printer LCD Projector Headphone plotter

COMPUTER SYSTEM = combination of 4 hardware components to accept and

process data, display and store the output.

4 hardware components

1. INPUT DEVICE

- = device to accept data / input by users to be processed.

3. OUTPUT DEVICE

= device to display the

data that has been

processed

2. PROCESSOR

= CPU will process

the input data into

useful information

4. STORAGE DEVICE

= device that store the

data / output for

future use



STORAGE DEVICE

Secondary Storage Primary Storage

RAM ROM

Magnetic medium

Hard disk

Floppy disk

Flash Memory

Pen drive

Memory card

Memory Stick

Optical Medium

CD ROM

DVD ROM

Blu Ray disk

CDR

CDRW



1. User key in (input) the data using input device.

2. The data will be processed by processor into useful information.

3. The processed data (info) will be displayed by output device such as monitor,

printer,...

4. The processed data (info) will be stored for future used.

**Types of data text, graphic, audio, video

Types of information text, chart, graphic, graph, total mark, video, audio.

INPUT

STORAGE

OUTPUT PROCESS



1. INPUT any data / instructions enter into the computer for processing.

Types of input Text Graphics Audio video

Input devices Keyboard

Scanner

Barcode reader

Optical reader

Scanner

Digital camera

microphone

MIDI keyboard

CCTV

Web cam

Digital camera

**pointing device mouse, trackball, graphic tablet, touch screen.

2. PROCESS process raw data into useful information.

done by CPU or processor



FETCH + DECODE = Instruction Cycle (I-Cycle)

EXECUTE + STORE = Execution Cycle (E-Cycle)

** I-Cycle + E-Cycle = Machine Cycle

3. OUTPUT data that has been processed / information

Can be – displayed (soft copy) dan printed (hard copy)

Types of output Text Graphics Audio video Output devices Printer

Scanner

Scanner

Speaker

Headphone

LCD projector

FETCH

STORE

EXECUTE

DECODE



4. STORAGE location which data / information is kept for future used.

Differences RAM vs ROM

DIFFERENCES RAM ROM

Data and Program Stores during and after processing

Stored by manufacturer

Content Temporary (sementara) Permanent (kekal kecuali padam)

Processing Time Very fast, but use a lot of power

Fast, use only little power

Volatility Volatile (meruap) -content loss when power is OFF

Non-volatile (tidak meruap) -content still have when power is OFF

STORAGE DEVICE

Secondary Storage Primary Storage

RAM ROM

Magnetic

medium

Hard disk

Floppy disk

Flash Memory

Pen drive

Memory card

Memory Stick

Optical Medium

CD ROM

DVD ROM

Blu Ray disk

CDR

CDRW



Differences Primary vs Secondary Storage

DIFFERENCES Primary Storage Secondary Storage Need Compulsory Alternative

Location Installed internally and can be accessed directly by CPU

External storage

Capacity of data stored

Store small amount of data Store large amount of data. Ex: hard disk

Access Speed Faster – because closer to CPU

Slow – because have to transfer by cable to CPU

Cost Expensive Cheap

Volatility Volatile (except ROM) Non-Volatile Save data Temporary Permanent



1. Computer only recognise 2 states : 0 and 1.

Each 0 and 1 is called “bit”.

Combination of 0 and 1 represents alphabets

symbols = characters

numbers

2. Bit = binary digit 0 = no/false/off

1 = yes/true/on

= the smallest unit of data

3. Byte = a collection of 8 bits to represent characters.

1 byte = 8 bits

1 byte = 1 character

8 bits = 1 byte = 1 character

Example :

01000011 = A , 01000010 = B

01100011 = a , 01100010 = b

8 bits = 1 byte

8 bits = 1 byte

1 character = 1 byte

1 character = 1 byte



such as Communication Codes smoke signals, morse code and semaphore

are used by people in the early days.

Computer use binary codes to communicate. One of the widely used binary

codes is the American Standard Code for Information Interchange (ASCII)

CHARACTER CODES

ASCII ( American Standard Code for

Information Interchange)

1 byte = 8 bits

ASCII represents 28 = 256 characters

EBCDIC (Extended

Binary Coded Decimal

Interchange Code)

UNICODE = use 2 bytes to

represent 1 character

2 bytes = 1 character

UNICODE represent > 65000

characters

UNICODE can represent other

world languages: Arabic,

Japanese, Chinese



1. Computer Speed = how fast it can process data / speed the computer can

turn data into information.

2. Micro processor contains a system clock.

system clock controls the speed of all operations within a computer.

the speed of the clock is measured by how many cycles per second the

clock makes.

Hertz the clock speed unit is measured in hertz.

A hertz is one cycle per second.

1 hertz = 1 cycle

1 second

MegaHertz (MHz) one million cycles of system clock.

1 MHz = 1 000 000 cycles 1 second

GigaHertz (GHz) one billion cycles of system clock

1 GHz = 1 000 000 000 cycles

1 second

1 GHz = 1000 MHz

3. Processing Speed = influence by system clock.

= a CPU with higher clock speed can process more instructions per second.

4. Microprocessor Speed = are determine by their clock speed and are usually

expressed in GigaHertz. (GHz).



SYSTEM SOFTWARE

Program that controls or

maintains the operations of

computer and its devices.

APPLICATION SOFTWARE

Program that perform specific

task for the user and help to

solve user’s problem.

OPERATING SYSTEM

Program that

coordinates all activities

among computer

hardware devices. It

enable computer to

start.

Examples : Windows,

Mac OS X, UNIX, LINUX

UTILITY PROGRAM

System software that

allow user to perform

maintenance-type-

tasks. (housekeeping)

Examples :

Antivirus

Antispyware

Diagnostic Utility

File Manager

Disk Defragmenter

Screen Saver

Driver.

Types of Application

Software:

Word Processing,

Spreadsheet,

Presentation software,

Database,

Web Browser,

Graphic Editing

Software.



BOOT = starting or restarting the computer.

Performs by operating system

WARM BOOT

Restarting the computer

that is powered on

COLD BOOT

Turn on the computer

that is powered off

Manage memory

Configure devices

Manage data

and programs

Provide

user

interface

Starting the computer



Disadvantage: 1. Difficult to use

because user has to memorise syntaxs and instructions

2. Not user friendly

Advantage : 1. User don’t have to

memorise teh syntax and commands

2. Easy to learn and use

Advantage: 1. Very user friendly 2. The easiest to use.



Proprietary Software / Close-Source Software

Open Source Software

Is a licensed software released / distributed by a company without its source code.

A software that the source code is available and user can modify it.

Advantage: 1. offer a stable system and support if

fails / malfunctions 2. updates and latest info is provided

by manufacturer.

Advantage: 1. Can be freely distributed 2. User receive the whole binary

version and source code. 3. User has the right to modify /

upgrade the software for better improvement, according to their needs.

Disadvantage: 1. cannot be freely distributed because

it is licensed. (user must purchase the software – company gain profit)

2. user do not receive source code. 3. user don’t have the right to modify

or redistribute the software.

Disadvantage: 1. Unstable system without support if

fails or malfunctions. 2. Updates and latest info. Only

available if user who modify / upgrade the software, redistribute it.

Examples : Operating System Windows,

Macintosh Application Software Google Earth,

Adobe Photoshop, Win RaR, Microsoft Office.

Examples: Operating System Android, Syllable OS,

MINIX, Ubuntu, LINUX, Haiku Application Software Joomla, Alfresco,

Koffice, NeoOffice, My SQL, Squirrel Mail, paint.net, ImageMagik, Blender, Scribus, Mozilla Firefox, VLC Media Player, Inkscape

la2 computer system

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