Form 4: 2.1.2.1 -State the relation of data representation : bit, byte and character

DATA REPRESENTATION

BINARY DIGIT
Computers recognize only two discrete states: on and off. These states can be represented by two digits, 0 and 1. Each 0 or 1 is called a bit in the binary system.

Bit is the smallest unit of data a computer can process. Bit is a short for binary digit. The binary system has a base of 2 with the two digits (0 and 1). Combinations of 0s and 1s represent larger numbers.

BIT
A bit is the smallest unit of data that the computer can process. Bit is a short for binary digit. A bit is represented by the numbers 1 and 0. These numbers represent the binary system. They correspond to the states of on and off, true and false, or yes and no.

All digital data use the binary system to process the information. This information include letters, digits or special character.

BYTE
Byte is a unit of information built from bits. One byte is equals to 8 bits. Eight bits that are grouped together as a unit. A byte provides enough different combinations of 0s and 1s to represent 256 individual characters.

One byte represents a single character such as the number 3, letter b
or a $ symbol. Bits and bytes are the basis for representing all meaningful information and programs on computers.

CHARACTER
8 bits = 1 byte

One byte represents one character such as A, 7, 9 and +.Eight bits that are grouped together as a unit. A byte provides enough different combinations of 0s and 1s to represent 256 individual characters.

For example, the capital letter F is represented by the binary code 01000110 that can be understood by the computer system. Eight bits grouped together as a unit are called a byte. A byte represents a single character in the
computer.

CHARACTER CODES
There are three character codes to represent characters which are ASCII, EBCDIC and Unicode. Each byte contains eight bits. A byte provides enough


different combination of 0s and 1s to represent 256 characters.

The combinations of 0s and 1s are defined by patterns. These patterns are called coding scheme. The 256-character capability of ASCII and EBCDIC is too small to handle the characters that are used by other languages such as
Arabic, Japanese and Chinese.

The Unicode coding scheme is designed to solve this problem. It uses two bytes (16 bits) to represent one character. Unicode will have more than 65,000 different characters. This can cover all the world’s languages.

INTRODUCTION TO BINARY CODING


COMMUNICATION CODES
Smoke signals, Morse code and semaphore are some of the communication codes used by people in the early days. In the information digital era, people send information via electronic devices such as through the computers.

Computers use binary codes to communicate. One of the widely used binary codes is the American Standard Code for Information Interchange (ASCII).

HISTORY OF CHARACTER CODES
Before people used binary codes such as ASCII to communicate via computers, character codes were widely used as a medium of communication. Let’s look at some of the character codes used prior to the use of ASCII.

2.1.3.1 - Explain the function of ASCII code.

WHAT IS ASCII?
ASCII pronounced as "ask-key" stands for the American Standard Code for Information Interchange and was proposed by ASA (American Standard Association) in 963 and was finalised in 1968.ASCII is a standard of 7-bit code used to represent characters, which include letters, numbers and punctuation marks.

7 bits allow the computer to encode a total of 128 characters for the numbers 0-9, uppercase and lowercase letters A-Z and a few punctuation symbols. However this 128 bit code only suitable for english language speaking users.

IBM and Apple expanded the amount of space reserved for the character codes to 8-bits, equivalent to 1 byte.

FUNCTIONS OF ASCII
ASCII was established to achieve compatibility between various types of data processing equipment making it possible for the components to communicate with each other successfully.

ASCII enables manufacturers to produce components that are assured to operate correctly in a computer.

ASCII makes it possible for humans to interact with a computer. It also enables users to purchase components that are compatible with their computer configurations.

HOW ASCII WORKS IN A COMPUTER SYSTEM?
When you press a key, for example the letter D on your keyboard, the electronic signal is sent to the CPU for the computer to process and store in memory. Every character is converted to its corresponding binary form. The computer the processes the letter as a byte., which actually a series of on and off of electrical states. When the computer is finished processing the byte, the software installed in the system convert the byte back which is then displayed in the screen. In this example, the letter D is converted to 01000100.

2.1.4.1 Describe the units of data measurement :
Bit
Byte
Kilobyte
Megabyte
Gigabyte
Terabyte

DATA MEASUREMENT

Why is 1024 bytes = 1KB?
20 = 1
21 = 2
22 = 4
23 = 8
24 = 16
25 = 32
26 = 64
27 = 128
28 = 256
29 = 512
210 = 1024

KILOBYTE (KB)
In mathematics, 1 KB = 1000 bytes.
In computer, 1 KB = 1024 bytes or
can be said as:

1 KB = 210 bytes

This is how we get the calculation for 1024 bytes.

MEGABYTE (MB)
1 MB = 1 048 576 bytes or it can be said as:

1 MB = 220 bytes

GIGABYTE (GB)
1 GB = 1 073 741 824 bytes or it can be said as:

1 GB = 230 bytes

TERABYTE (TB)
1 TB = 1 099 511 627 776 bytes or it can be said as:

1 TB = 240 bytes

2.1.5.1 Describe the units of clocks speed measurements :
Megahertz
Gigahertz

CLOCK SPEED MEASUREMENT

EVOLUTION OF COMMUNICATION
When people talk about a computer’s “speed”, they mean how fast it can process data. In other words, this means the speed the computer can turn data into information.

Every microprocessor contains a system clock. The system clock controls the speed of all the operations within a computer. The speed of the clock is measured by how many cycles per second the clock makes.

HERTZ AND SECONDS
The clock speed unit is measured in hertz. A hertz is one cycle per second.

MEGAHERTZ (MHz)
Mega is a prefix that stands for million. Thus, megahertz (MHz) equals to one million cycles of the system clock. A computer that operates at 933 MHz (megahertz) has 933 million clock cycles in one second.

GIGAHERTZ (GHz)
Giga is a prefix that stands for billion.Gigahertz (GHz) equals to one billion cycles of the system clock.In relation with megahertz,1.0 GHz is equivalent to 1000 MHz.

For example, a microprocessor that runs at 200 GHz executes 200 billion cycles per second. This is what they are talking about if they say a computer is a 2.4 GHz machine. Its clock rate is 2.4 billion cycles per second.
GHz is most often used as a measurement of a PC processor chip and power, with bigger numbers meaning more speed and higher price.

PROCESSING SPEED

The system clock is one of the major factors that influence the computer speed. A CPU with a higher clock speed can process more instructions per second than a CPU with a lower clock speed. For example, a 1 GHz CPU is faster than a CPU operating at 800 MHz. The speed of the system clock affects only the CPU. It has no effect on peripherals such as a printer or disk drive.

MICROPROCESSOR SPEED

One way of comparing the performance of personal computers is by comparing their microprocessor speeds. Microprocessor speeds are determined by their clock speed and are usually expressed in gigahertz (GHz), billion of machine cycles per second.

For example, a personal computer that is listed at 2.2 GHz has a processor capable of handling 2.2 billion machine cycles per second. A top speed personal computer can be much faster, with newer ones exceeding 3.0 GHz.
Direct comparison of clock is meaningful between identical microprocessor.

Thus, it is accurate to say that a Pentium 4 running at 2.4 GHz is approximately one-third faster than a Pentium 4 running at 1.8 GHz.

SPEED AND PATH
The combination of speed and number of paths determines the total processing speed or channel bandwidth. This is because different processors
often use different architectures. For this reason, a 1.4 GHz Pentium 4 performs better than a 1.4 GHz Pentium 3, but it is not as fast as a 1.4 GHz Power PC G4 processor.

Form 4: 2.1.1.1 - Define computer system.

OVERVIEW OF COMPUTER SYSTEM

COMPUTER SYSTEM

A computer system is defined as combination of components designed to process data and store files.

A computer system consists of four major hardware components; input devices, output devices, processor and storage devices.

A computer system requires hardware, software and a user to fully function.

Software refers to set of instructions that tell the hardware what to do. Software can also have various other functions such as performing computation, communication with other software and human interaction.

User refers to a person who uses the computer for any purposes such as work, business and entertainment.

COMPUTER HARDWARE

Computer hardware consists of:
input devices
processor
output devices
storage devices

Input Devices
Input devices feed data or commands in a form that the computer can use. Example of input devices are:

§ Keyboard
§ Light Pen
§ Joystick
§ Microphone
§ Mouse
§ Video
§ Digital camera.

Processor
The CPU is an example of a processor. It has the same important as the brain to human being.

Output Devices
Output devices such as the monitor shows people the process data or information. This type of information can be understood and use by computer user. Other example of output devices are:
§ Printer
§ Plotter
§ Speaker

Storage Devices
Storage usually means secondary storage. It consists secondary storage devices such as hardisk, Floppy Disk, diskette, CD ROM and DVD ROM.

COMPUTER SOFTWARE
There a 2 types of computer software, system software and application software. System software is any computer software that helps to run computer system. System software controls, integrate and manages the individual component of a computer system.

2.1.1.3 - Describe the information processing cycle which
includes input, process, output and storage using a block diagram.

COMPUTER HARDWARE BLOCK DIAGRAM

An Input device feed raw data to the processor. A processor processes raw data and turns it into useful information. A storage device keeps or stores both process and unprocess data for later usage. An output device shows or display the processed data.

INPUT DEVICES

When data is entered into the computer system, it is called an input. Input
comes in various forms; texts, graphics, audio and video. Input devices are
needed to input data into the computer system.

Keyboard, mouse, scanner, barcode reader and digital camera are some example of input devices.

OUTPUT DEVICES
Output is the result of raw input data that has been processed by the central processing unit into meaningful information. Common forms of output are texts, numbers, graphics, sounds, animations and videos.The most common output devices are computer screens, speakers and printers.

STORAGE DEVICES

The system’s primary storage, Random Access Memory (RAM) can only hold data temporarily. Thus, secondary storage is needed to provide additional storage. The data stored in the secondary storage is considered permanent until it is deleted or removed.

Secondary storage can be magnetic disks and optical disks. Examples of secondary storage are hard disks, rewritable CDs and DVDs as well as removable disks such as pen drives.

PERIPHERAL DEVICES

External hardware devices attached to the computer are called peripheral equipments.

INFORMATION PROCESSING CYCLE

Do you know how a computer works? We use the computer in our everyday lives but not all of us know how this machine operates.

Human uses the brain to think, make decisions and process information. A computer has a brain too, and the brain of a computer is the processor or the central processing unit (CPU) that processes information.

THE CENTRAL PROCESSING UNIT
The central processing unit or the CPU is the brain of the computer.

All processing activities are done in the CPU. It utilises the computer memory to execute instructions from the application software and accomplish a task. For example: editing a letter, drawing a picture and sorting numbers.

The processor must be connected to input devices, output devices and storage devices to carry out the above mentioned tasks.

THE INFORMATION PROCESSING CYCLE

User will input the data to be processed by the processor.

The storage holds databases, files and programs. The output devices
present the processed data as useful information products for the user.

INPUT
Input is any data or instructions that we enter into the computer system for processing.

There are some common ways of feeding input data into the system, which are:

• typing on a keyboard
• pointing with a mouse

CPU accepts instruction from the user and translates the instruction into readable information (decode).

PROCESS
The processing unit controls all activities within the system. For every instruction, the control unit repeats a set of four basic operations called the machine cycle:

Fetching
the process of obtaining a program instructions or data item from memory.

Decoding
the process of translating a program instruction into signals that the computer can execute.

Executing
the process of implementing the instructions in a program.

Storing
the process of writing the result to the storage or memory.

STORAGE
Storage is a location which data, instruction and information are held for future use. Every computer uses storage to hold system software and application software.

When we issue a command to start the application software, the operating system locates the program in storage and loads it into memory.

A storage medium, also called secondary storage is the physical material in the computer that keeps data, instruction and information.

A storage device is the computer hardware that records or retrieves items to and from storage media.

OUTPUT
Output is data that has been processed into a useful form, called information. There are four types of output, which are texts, graphics, audio and video.

The text consists of characters that are used to create texts, sentences and paragraphs.

Graphics are digital representations of non text information such as drawings, charts and photographs.

Audio is music, speech or any other sound. Video consists of images that
provide the appearance of full motion.

FORM 4: ASSESSMENT 3

ASSESSMENT 3

LEARNING AREA: INFORMATION AND COMMUNICATION TECHNOLOGY AND SOCIETY

IMPACT OF ICT ON SOCIETY: LOCATE AND PRESENT INFORMATION ON IMPACT OF ICT ON SOCIETY


PLEASE DO THE ASSESSMENT & FOLLOW THE CRITERION BELOW:

1. LOCATE THE INFORMATION FROM MORE THEN ONE SOURCE.
WRITE THE NUMBER OF SOURCES REFFERED – WEBSITE, BOOK, MAGAZINE, NEWSPAPER EXT.
* CANDIDATES LOCATE INFORMATION IN GROUPS OF 2-4 BUT MUST PREPARE AND PRESENT SLIDES INDIVIDUALLY.

2. PRESENT THE INFORMATION IN 5 TO 10 SLIDES.
CHOOSE 1 OF THE FOLLOWING TOPICS:
- COPYRIGHT AND PRVACY FROM MORAL (ETHICAL) AND LEGAL STANDPOINT
- LACK OF SECURITY AND ITS EFFECTS ON INDUSTRY/ECONOMY/GOVERNMENT
- MALAYSIAN CYBER LAW, ELECTRONIC GOVERNMENT LAW
- VIRUS
- HACKING
- SECURITY MEASURE (BIOMETRICS, AUTHENTICATION EXT)

3. PRESENTATION INCLUDES:
- TOPIC
- CONTENT
- CONCLUSION
- SOURCES OF REFERENCE
SUBMIT SOFT COPY AND HARD COPY OF THE PRESENTATION

4. DISPLAY COOPERATION
- WRITE THE NAME OF GROUP MEMBER
- VERBAL VERIFICATION FROM GROUP MEMBERS OR ASSESSOR’S OBSERVATION

• SUGGESTED PRESENTATION DURATIONS: 5 MINUTES
• COMPLETE ALL 4 TASK!! FULL MARK!!

FORM 4: ASSESSMENT 2

ASSESSMENT 2

LEARNING AREA: INFORMATION AND COMMUNICATION TECHNOLOGY AND SOCIETY

COMPUTER SECURITY MEASURE: APPLY CORRECT SECURITY PROCEDURES USING ANTI-SPYWARE


PLEASE DO THE ASSESSMENT & FOLLOW THE CRITERION BELOW:


1. CHOOSE ANTI-SPYWARE TO BE USED. WRITE THE NAME OF THE ANTI-SPYWARE

2. START THE ANTI-SPYWARE SOFTWARE AND SELECT AREA TO BE SCANNED ( SCAN PENDRIVE)

3. SCAN SELECTED AREA. PRINT SCREEN SCAN SUMMARY

4. CHOOSE AND APPLY ANY OR ALL OF THE FOLLOWING WHEN VIRUS IS DETECTED –REMOVE/QUARANTINE.
STATE THE ACTION

• IF NO VIRUS DETECTED, CRITERION 4 IS CONSIDERED DONE. WRITE “NO ACTION TAKEN”

• COMPLETE ALL 4 TASK!! FULL MARK!!

Form 4: ASSESSMENT 1

ASSESSMENT 1

LEARNING AREA: INFORMATION AND COMMUNICATION TECHNOLOGY

AND SOCIETY

COMPUTER SECURITY MEASURE: APPLY CORRECT SECURITY

PROCEDURES USING ANTIVIRUS

PLEASE DO THE ASSESSMENT & FOLLOW THE CRITERION BELOW:

1. CHOOSE ANTIVIRUS TO BE USED.

WRITE THE NAME OF THE ANTIVIRUS

2. START THE ANTIVIRUS SOFTWARE AND SELECT AREA TO BE SCANNED ( SCAN PENDRIVE)

3. SCAN SELECTED AREA. PRINT SCREEN SCAN SUMMARY

4. CHOOSE AND APPLY ANY OR ALL OF THE FOLLOWING WHEN VIRUS IS DETECTED – DELETED/REMOVE/CLEAN/HEAL/QUARANTINE/MOVE TO VAULT.

STATE THE ACTION

• IF NO VIRUS DETECTED, CRITERION 4 IS CONSIDERED DONE. WRITE “NO ACTION TAKEN”

• COMPLETE ALL 4 TASK!! FULL MARK!!

Form 2: The Program Development Life Cycle

When we want to produce a program, we need to go through a few phases. There are
five main phases in program development;

Let’s look at the descriptions of each main phase in program development:

1. Problem Analysis
What is problem analysis?
You need to identify the problem before developing a program. Let’s imagine
that you are a programmer.
As a programmer, you are contacted because your services are needed. You
meet with users from the client organization to analyze the problem, or you meet
with a systems analyst who outlines the project. Specifically, the task of defining
the problem consists of identifying what it is you know (input-given data), and
what it is you want to obtain (output-the result). Eventually, you produce a written
agreement that, among other things, specifies the kind of input, processing, and
output required. This is not a simple process.

2. Program Design
In this phase, you will do the following tasks :-
• Plan the solution to the problem (think about how will you solve the problem)
• Choose the interface (think about how will your program look like)

3. Coding
So now you are ready to write the code of the program that you have planned.
You need to express your solution in a programming language.
The normal process you will go through is to translate the logic from the flowchart
or pseudocode-or some other tool-to a programming language.

As we have already noted, a programming language is a set of rules that
provides a way of instructing the computer what operations to perform. There
are many programming languages: BASIC, COBOL, Pascal, FORTRAN, and
C are some examples. You may find yourself working with one or more of
these. However in this module, we will either produce a program using
Microsoft VB-express or Just BASIC v1.01.
Although programming languages operate grammatically, somewhat like the
English language, they are much more precise. To get your program to work,
you have to follow exactly the rules-the syntax-of the language you are using.
Of course, using the language correctly is no guarantee that your program
will work, any more than speaking grammatically correct English means you
know what you are talking about. The point is that correct use of the language
is the required first step. Then your coded program must be keyed, probably
using a terminal or personal computer, in a form the computer can
understand.
One more note here: Programmers usually use a text editor, which is
somewhat like a word processing program, to create a file that contains the
program. However, as a beginner, you will probably want to write your
program code on paper first.

4. Testing and Debugging
The fourth phase is to test and debug your program.
Why do you need to test?
The imperfections of the world are still with us, so most programmers get used to
the idea that their newly written programs probably have a few errors. This is a
bit discouraging at first, since programmers tend to be precise, careful, detailoriented
people who take pride in their work.
Still, there are many opportunities to introduce mistakes into programs, and you,
just as those who have gone before you, will probably find several of them.

Why debug?
You need to debug to improve your program. Debug is a term used extensively
in programming. “Debugging” means detecting, locating, and correcting bugs
(mistakes), usually done by running the program.
These bugs are logic errors, such as telling a computer to repeat an operation
but not telling it how to stop repeating. In this phase you run the program using
test data that you devise. You must plan the test data carefully to make sure you
test every part of the program.
How do you debug?
You can carry out debugging by running the program. The following are
examples of debugging for Visual Basic Express and Just BASIC.

a. debugging button in Visual Basic Express


5. Documentation
Documentation is important when programming. Documenting is an ongoing,
necessary process, although, as many programmers are, you may be eager to
pursue more exciting computer-centered activities.
What is documentation?
Documentation is a written detailed description of the programming cycle and
specific facts about the program. Typical program documentation materials
include the origin and nature of the problem, a brief narrative description of the
program, logic tools such as flowcharts and pseudocode, data-record
descriptions, program listings, and testing results.
Comments in the program itself are also considered an essential part of
documentation. Many programmers document as they code. In a broader sense,
program documentation can be part of the documentation for an entire system.
The wise programmer continues to document the program throughout its design,
development, and testing. Documentation is needed to supplement human
memory and to help organize program planning. Also, documentation is critical to
communicate with others who have an interest in the program, especially other
programmers who may be part of a programming team.
Written documentation is needed in computer industry so that those who come
after you can make any necessary modifications in the program or track down
any errors that you missed.

Form 2: Introduction to programming

1. What is programming?
Programming refers to the act of instructing the computer to do something for us
with the help of programming language.

2. What is a programming language?
A Programming Language is a set of rules that provides a way of telling the
computer what operation to perform (according to Capron and Johnson,2004)

3. What programming languages are available?
Before looking at a specific programming language, we need to know the levels of
programming languages.

Language is said to be “lower” or “higher” depending on how close they are to the
language the computer itself uses or to the language people use (more English-likehigh).

These programming languages are generally divided into five levels or generations :-
a. Machine Language
b. Assembly Language
c. High-Level Language
d. Very High-Level Language
e. Natural Language

4. Examples of Programming Languages.
Examples of programming languages are :-
a. BASIC
b. COBOL
c. PASCAL
d. C
e. FORTRAN
f. VISUAL BASIC
g. C++
h. JAVA

a. Example of C programming:


b. Example of Visual Basic

(Latest) Form 4: 1.4.1.2 Describe the impact of ICT on society.

COMPUTER APPLICATIONS IN THE SOCIETY

The computer has change the society today as much as industrial revolution changed society in 18th and 19th century. People interacts directly with computer in education, finance, government, health care, science, publishing, tourism, and industry.

Computers help them to do their work faster and more efficient by using the software application that consist of special program for specific task.

SOFTWARE APPLICATIONS

Software applications are used for many reasons. Such as to enhance the learning process, to help in business activities, to assist the graphics and multimedia project and to fasilitate communication.

These software application comes in packages.

SOFTWARE APPLICATIONS PACKAGES

HOME AND EDUCATION

Today, computers are used in schools, colleges and universities in order to promote better education by using computers. In the labs, students use software packages to complete their assignments. At the same time, some educators use the computer-based training and web-based training as replacements for lecture presentation.

Some of the software applications that are usually used in schools and universities include Microsoft Office, Adobe Photoshop, Macromedia Flash, AutoCAD, Macromedia Dreamweaver and Macromedia Director.

COMPUTERS FOR HIGHER EDUCATION

Open Distance Learning (ODL) or online learning can be implemented as computers are the main medium in

delivering the knowledge from one location to the other locations.

This type of learning consists of online forum, discussion, quizzes, test questions and many more. The example of the Open Distance Learning institution is the Open University of Malaysia (www.oum.edu.my).

BUSINESS

People use finance or accounting software to balance check books, pay bills, track personal income and expenses, manage investments and evaluate their financial plans.

Accounting software helps companies to record and report their financial transactions. Examples of these software applications include MYOB, Intuit Quick Books and Peachtree Complete Accounting.

COMPUTERS IN BANKING

In the banking sector, many financial institutions offer online banking. People can access their financial records from anywhere in the world. One example of online banking is Maybank2u. (www.maybank2u.com)

Most of the packages on banking offer a variety of online services. Which requires access to the web.

For example we can track our investment online, compare insurance rates and do online banking.

INDUSTRY

By using the CAM system, computers record actual labour, material, machine and computer time used to manufacture a particular product.

Computers process this data and automatically update inventory, production, payroll and accounting records on the company’s network.

Examples of companies using this system are Proton(www.proton.com.my) and Perodua (www.perodua.com.my).

GRAPHICS AND MULTIMEDIA

Computers are crucial in publishing especially in the process of making works available to the public. These works include magazines, books, newspapers, music and film production.

Special software applications are used to assist graphic designers to develop graphics, texts, photographs and composing songs.

Computer-Aided Design, Desktop Publishing, Paint/Image Editing, Video and Audio Editing and Multimedia Authoring are among the popular applications software.

COMMUNICATION

A government provides society with direction by

making and administering policies. Most government

offices or agencies have websites in order to provide

citizens with up-to-date or latest information.

Examples of software applications used for communication include e-mail, web browsers, newsgroups, instant messaging and video conferencing.

People can access government websites to:

• check information on taxes (www.hasil.org.my)
• apply for permits and licenses (www.jpj.gov.my)
• check for MyKad (www.jpn.gov.my)
• pay parking tickets and check summons (www.jpj.gov.my)
• renew vehicle registration (www.jpj.gov.my)
• register online for IPTA/IPTS application (www.moe.gov.my)

COMPUTERS IN TOURISM

Today, people will go online to get all related information about traveling. They can visit websites to get information on destinations, prices, hotels, flights and car rentals.

They can also purchase ticket online, all payments can be made by using credit card.

COMPUTERS IN THE HEALTHCARE

In the medical field, computers are very important in running the operations. Medical staffs use computers for various purposes, namely:

• maintaining patient records
• monitoring patients’ vital sign
• assisting doctors, nurses and technicians with medical tests by using computer and computerised devices .
• using medical software to help with researching and diagnosing health conditions.

Furthermore, computers and the internet are important sources for people to get all information on medical, nutrition, fitness and other tips from several available websites. The latest development in the medical field is telemedicine. This technology is meant to help professional to conduct live conference in separate locations around the globe.

SCIENCE

In the scientific world, computers are used in all fields of science from biology to astronomy to meteorology and others. These are things that

can be done by computers, namely:

• collecting, analyzing and modelling data
• serving as medium of communication with colleagues around the world
• contributing to new inventions or breakthrough in surgery, medicine and treatment
• imitating functions of the central nervous system, retina of the eye and others by tiny computers
• allowing a deaf person to listen through cochlear implant

LESSON 22

COMPUTER USERS

People around the world rely on computers to do so many things. They are from different backgrounds and are divided in 5 categories.

HOME USER

The computer is a basic necessity. Each home user spends time on the computer for different reasons:

• business
• communication
• entertainment
• education

SMALL OFFICE/HOME OFFICE (SOHO) USER

SOHO users use computer to manage their work effectively. They advertise their products and services through websites. They also take orders from the websites.

To save cost, SOHO connects one printer to many employees to share. SOHO also have their own basic business software such as word processing and spreadsheet software to assist them in documents preparation and their financial tasks.

Small Office or Home Office users include:

• accounting firms, travel agencies, florists and many more

These SOHO users:

• use desktop or notebook computers as well as telephone, handphones and PDAs in completing their tasks and communicating
• work in a small company or work as an individual at home

MOBILE USER

Network services are expanding to serve people across the country and the world. More users are becoming mobile users, who work on computer while they are away from their home or main offices.

Mobile users:

• include real estate agents, insurance agents, meter readers and journalists
• use notebook computers, Internet-enabled PDAs or smart phones
• work with basic business software such as word processing and spreadsheet business software
• use presentation graphics software to create and deliver presentations to a large
• audience by connecting a mobile computer or device to a video projector

POWER USER

Power users require the capabilities of workstation computers or other types powerful computers. The software that is used by power users is normally expensive because of their specialize design. Their computer have network access connections and internet connections.

Power users:

• include engineers, scientists, architects and virtual reality animators
• use computers with extremely fast processor, bigger storage and customised software
• work with mini computers that uses design to meet the organisational needs
• use software such as CAD, CAM and MATLABExamples :

LARGE BUSINESS USER

Each employee or customer who uses computer in large offices of company is a large business user. Large business users use a large network of computers. Use computers for basic business activities such as preparing bills for millions of customers, preparing payroll and managing thousands of items in the inventory.

Large business users:

• bank, insurance company, hypermarket
• use computers for basic business activities
• have e-commerce that allow customers and vendors to interact and do business transactions online therefore customers, vendors and other interested parties can access information on the web
• have e-mail and web browsers to enable communications among employees, vendors and customers
• provide kiosks in public locations

Many employees of large business telecommute, which means they work away from their offices workstation. They also have flexible schedule.

(Latest) Form 4: RELATIONSHIP BETWEEN SECURITY THREATS AND SECURITY MEASURES

Security threats may come from in many forms. For example, when someone is invading your account information from a trusted bank, this act is considered as a security threat.

Security measures can be used to prevent this invader from getting the account information. For example, the bank can use a firewall to prevent unauthorised access to its database.

SECURITY THREADS
Security threats may come from in many forms. For example, when someone is invading your account information from a trusted bank, this act is considered as a security threat.

Security measures can be used to prevent this invader from getting the account information. For example, the bank can use a firewall to prevent
unauthorised access to its database.

MALICIOUS CODE THREATS VS. ANTIVIRUS AND ANTI-SPYWARE
Security threats include virus, Trojan horse, logic bomb, trapdoor and backdoor, and worm.

Antivirus and anti-spyware can be used to protect the computer from the threats by:

 limiting connectivity
 allowing only authorised media for loading data and software
 enforcing mandatory access controls
 blocking the virus from the computer program

HACKING VS. FIREWALL
Hacking is an unauthorised access to the computer system done by a hacker. We can use firewall or cryptography to prevent the hacker from accessing our computers.

A firewall permits limited access to unauthorised users or any activities from the network environment. Cryptography is a process of hiding information by changing the actual information into different representation, for example, an APA can be written as 7&*.

NATURAL DISASTER VS. DATA BACKUP
The natural and environmental disasters may include:
• flood
• fire
• earthquakes
• storms
• tornados

Natural disasters may threaten a computer’s hardware and software easily. Computers are also sensitive to their operating environment such as
excessive heat or the inadequacy of power supply.

The backup system is needed to backup all data and applications in the computer. With the backup system, data can be recovered in case of an emergency.


THEFT VS. HUMAN ASPECTS
Computer theft can be of two kinds:

 can be used to steal money, goods, information and computer resources
 the actual stealing of computers, especially notebooks and PDAs

Measures that can be taken to prevent theft:

 prevent access by using locks, smart-card or password
 prevent portability by restricting the hardware from being moved
 detect and guard all exits and record any hardware transported

BE SUPSPICIOUS OF ALL RESULTS
There are many instances where non-programmers develop applications which are not built with proper understanding of software engineering practices.

Data produced by such applications may not be correct and may risk corrupting data received from other sources that are not compatible with the application.

SECURITY PROCEDURES

Computers should have alarm systems to guard them from any attacks such as viruses and data corruption. The alarm system is the security measures that we take to ensure its safety.

DATA PROTECTION
We need to protect the data in the computer as it may somehow get lost or corrupted due to some viruses or mishap like fire, flood, lightning, machine
failures and even human errors.

There are a few ways to protect the information namely:
• make backup files
• detect the virus and clean the computer
• warn others on virus attacks

1) BACKUP FILES
Users can do backups of file systems by:
 keeping the duplicated files in external storage such as in the floppy disk and thumb drive
 do backup frequently

2) DETECT VIRUS AND DO CLEANUP
A computer virus is able to affect and infect the way the computer works. Viruses can be detected when we run an antivirus program.We can also delete the infected files and documents.

3) WARN OTHERS ON VIRUS ATTACK
We can warn others on virus attacks or new viruses by sending e-mails to them.

DETECTING ILLEGAL ACCESS TO SYSTEMS
The computer system is able to detect any illegal access to the system by a user who does not have any authorisation. Basically, a corporation will simply use tcpwrappers and tripwire to detect any illegal access to their system. User's access will be reviewed periodically by computer operations. On going internal audits will be made to ensure detection of violations of security and unauthorised modifications to software and data .

TCPWRAPPERS

Tcpwrappers stop the attempted connection


examines its configuration files


will decide whether to accept or reject the request.

Tcpwrappers will control access at the application level, rather than at the socket level like iptables and ipchains. The system will run tcpwrappers to log access to ftp, tftp, rch, rlogin, rexec and telnet.

TRIPWIRE
Tripwire will detect and report on any changes in the thousands of strategic system files.

The system will run tripwire to determine if system files have changed.

PREVENTING ILLEGAL ACCESS TO SYSTEMS
Have any of you ever been to an airport? Do you know the do’s and don’ts when you are at the airport?

There are things that cannot be taken inside the airplane. It is for the purpose of security procedures.

It is the same as computer systems. It would not allow any unauthorised users to simply access the system.

Ways to prevent illegal access to systems:

1. Run anlpassword to make password cracking difficult.
2. Run tcpwrappers to check if the name for an ip address can be provided by DNC
3. Use a callback system to prevent unauthorised use of stolen passwords.

PREVENTING ILLEGAL ROOT ACCESS
To prevent any illegal root access, we should have Sudo, so that people can perform on some machine without getting access to the entire root if that is not required. In addition, with Sudo we did not have to give out the root password.

Sudo stands for (Superuser do) and is a program in Unix, Linux and similar operating systems such as Mac OS X that allows users to run programs in the form of another user (normally in the form of the system's superuser).

Sudo allows a permitted user to execute a command as the superuser or another user, as specified in the sudoers file.

PATCH
Patch supplies small updates to software, provided that the source code is available.

Patch is a name of an UNIX utility. It applies a script
generated by the different program to a set of files
that allows changes from one file to be directly applied to another file.

Resources are not enough to patch all security holes that we hear about through the bugtraq list.

(Bugtraq is a full disclosure mailing list dedicated to the issues of computer security. On-topic discussions are new discussions about vulnerabilities, methods of exploitation and how to fix them. It is a high volume
mailing list and almost all new vulnerabilities are discussed there.)

(Latest) Form 4: 1.3.3.1 - Select appropriate security measures to overcome the identified computer threats.

SECURITY MEASURES

Today, people rely on computers to create, store and manage critical information. It is important that the computer and the data they store are accessible and available when needed. It is also important that users take measures to protect their computers and data from lost, damage and misused.

Security measures mean the precautionary measures taken toward possible danger or damage. There are 6 type of security measures.

1.3.3.2 - Apply the correct security procedures.

-- Antivirus

- Anti-Spyware

- Cryptography

- Firewall

- Data backup

1) DATA BACKUP

Data Backup is a program of file duplication. Backups of data applications are necessary so that they can be recovered in case of an emergency.

Depending on the importance of the information, daily, weekly or biweekly backups from a hard disk can be performed.

2) CRYPTOGRAPHY

Cryptography is a process of hiding information by altering the actual information into different representation, for example, an APA can be

written as I? X.

Almost all cryptosystems depend on a key such as a

password like the numbers or a phrase that can be used to encrypt or decrypt a message.

The traditional type of cryptosystem used on a computer network is called a symmetric secret key system.

3) ANTIVIRUS

An antivirus program protects a computer against viruses by identifying and removing any computer viruses found in the computer memory, on

storage media or incoming e-mail files.

An antivirus program scans for programs that attempt to modify the boot program, the operating system and other programs that normally are read from but not modified.

IDENTIFYING VIRUS

Two technique are used to identify the virus:

a) VIRUS SIGNATURE

Also called a virus definition is a specific pattern of the virus code.

b) INOCULATING A PROGRAM FILE

The antivirus program recordsinformation such as the file size and file creation date in a separate inoculation file.

The antivirus program then uses this information to detect if a virus tampers with the data describing the inoculated program file.

If an antivirus program identifies an infected file, it attempts to remove its virus, worm or Trojan horse. If the antivirus program cannot remove the infection, it often quarantines the infected file. Quarantine is a separate

area of a hard disk that holds the infected file until the infection can be removed. This step ensures other files will not become infected. Patents for inventions Utility, design or plant patents that protect inventions and improvements to existing inventions

4) ANTI-SPYWARE

Spyware is a program placed on a computer without the user’s knowledge. It secretly collects information about the user.

The spyware program communicates information to

the outside source.

An anti-spyware application program sometime called tracking software or a spybot is used to remove spyware.

Among of the popular anti-spyware programs are:

• Spybot Search and Destroy

• Ad-aware

• Spyware Blaster

5) FIREWALL

Firewall is a piece of hardware or software which functions in a networked environment to prevent some communications forbidden by the security

policy.

Firewall implement a security policy. It might permit limited access from in or outside the network perimeters or from certain user or for certain activities.

6) HUMAN ASPECTS OF SECURITY MEASURES

Human aspects refer to the user and also the intruder of a computer system.

It is one of the hardest aspects to give protection to.

The most common problem is the lack of achieving a good information security procedure.