LEARNING AREA 2 NOTES: COMPUTER SYSTEM

7/27/2019 LEARNING AREA 2 NOTES: COMPUTER SYSTEM

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LA 2: Computer System 2013

Panitia ICT SMK Perlis Page 1

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 toaccept 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. OUTPUTDEVICE

= device to

display the data

that has been

processed

2. PROCESSOR

= CPU will

process the

input data into

useful

information

4. STORAGEDEVICE

= device that

store the data /

output for future

use

STORAGE DEVICE

Primar Stora e


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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

OUTPUTPROCESS


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

Types of input Text Graphics Audio videoInput devices Keyboard

ScannerBarcode

reader

Opticalreader

ScannerDigital

camera

microphoneMIDI

keyboard

CCTV Web cam Digital

camera

**pointing devicemouse, trackball, graphic tablet, touch screen.

2. PROCESS process raw data into useful information.done by CPU or processor


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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 PrinterScanner Scanner SpeakerHeadphone LCDprojector

FETCH

STORE

EXECUTE

DECODE


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4. STORAGElocation 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 StoragePrimary Storage

RAMROM

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


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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


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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 b te8 bits

= 1 b te

1 character 1 character


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such asCommunication 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 BinaryCoded Decimal

Interchange

Code)

UNICODE

= use 2 bytes torepresent 1 character

2 bytes = 1 character

UNICODE represent >

65000 characters

UNICODE can represent

other world languages:Arabic, Japanese,

Chinese


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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 secondthe 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 areusually expressed in GigaHertz. (GHz).


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SYSTEM SOFTWARE

Program that controls or

maintains the operations

of computer and itsdevices.

APPLICATION SOFTWARE

Program that perform specific

task for the user and help to

solve users 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 toperform

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.


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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


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Disadvantage:

1. Difficult to use

because user

has tomemorise

syntaxs and

instructions

2. Not user

friendly

Advantage :

1. User dont have

to memorise teh

syntax andcommands

2. Easy to learn and

use

Advantage:

1. Very user

friendly

2. The easiest touse.


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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 companygain profit)

2. user do not receive source code.

3. user dont have the right to

modify/ redistribute the software.

Disadvantage:

1. Unstable system without support if

fails or malfunctions.

2. Updates and latest info. Onlyavailable if user who modify /

upgrade the software, redistribute

it.

Examples :

Operating SystemWindows,

Macintosh

Application Software Google

Earth, Adobe Photoshop, Win

RaR, Microsoft Office.

Examples:

Operating System Android, Syllable

OS, MINIX, Ubuntu, LINUX, Haiku

Application SoftwareJoomla,

Alfresco, Koffice, NeoOffice, My

SQL, Squirrel Mail, paint.net,

ImageMagik, Blender, Scribus,

Mozilla Firefox, VLC Media Player,

Inkscape


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LEARNING AREA 2 NOTES: COMPUTER SYSTEM