BYTE

Bait merujuk kepada unit data yang terdiri daripada 8 bit yang digunakan secara meluas oleh kebanyakan komputer peribadi. Bait mewakili aksara seperti huruf abjad, nombor dan simbol tipografi.
Huruf "B" digunakan dalam singkatan kepada bait. (bit menggunakan singkatan "b".) seperti kB = Kilobait. Cakera keras berkapasiti 40GB secara mudahnya bermaksud cakera keras berkenaan mampu menyimpan sehingga 40 ribu juta (billion) bait atau Gigabait data.
Bait didarabkan berasaskan kuasa 2 dan dalam sebutan biasa, angka perpuluhannya dibulatkan. Sebagai contoh, 1 Gigabait disebut sebagai 1 ribu juta bait walaupun angka sebenarnya ialah 1,073,741,824 bait.
Sebagai panduan:

• 1 aksara = 8 bit = 1 bait
• 1024 bait = 1 Kilobait - KB (ribu) = 1,024 bait
• 1024 Kilobait = 1 Megabait - MB (juta) = 1,048,576 bait
• 1024 Megabait = 1 Gigabait - GB (billion) = 1,073,741,824 bait
• 1024 Gigabait = 1 Terabait - TB (trillion) = 1,099,511,627,776 bait
• 1024 Terabait = 1 Petabait - PB (juta Gigabait) = 1,125,899,906,842,624 bait
• 1024 Petabait = 1 Exabait - EB (juta Terabait) = 1,152,921,504,606,846,976 bait
• 1024 Exabait = 1 Zettabait - ZB (juta Petabait)
• 1024 Zettabait = 1 Yottabait - YB (juta Exabait)      

Kuantiti bait
Awalan SI		Kegunaan sejarah		Awalan perduaan
Simbol (nama)	Nilai	Simbol	Nilai	Simbol (nama)	Nilai
kB (kilobait)	10001 = 103	KB	10241 = 210	KiB (kibibait)	210
MB (megabait)	10002 = 106	MB	10242 = 220	MiB (mebibait)	220
GB (gigabait)	10003 = 109	GB	10243 = 230	GiB (gibibait)	230
TB (terabait)	10004 = 1012	TB	10244 = 240	TiB (tebibait)	240
PB (petabait)	10005 = 1015	PB	10245 = 250	PiB (pebibait)	250
EB (eksabait)	10006 = 1018	EB	10246 = 260	EiB (eksbibait)	260
ZB (zetabait)	10007 = 1021	ZB	10247 = 270	ZiB (zebibait)	270
YB (yotabait)	10008 = 1024	YB	10248 = 280	YiB (yobibait)	280

Unit Warisan
Unit	Nilai
KB	210 Bait = 1024 Bait
MB	220 Bait = 1024 KB
GB	230 Bait = 1024 MB
TB	240 Bait = 1024 GB

Introduction Of Binary Coding

ASCII (kep. "American Standard Code for Information Interchange", BM: "Kod Piawai Amerika untuk Pertukaran Maklumat") adalah satu format yang lazim digunakan untuk fail teks dalam komputer dan internet. Kod ASCII telah dibangunkan oleh American National Standards Institute (ANSI).

Dalam fail yang menggunakan kod ASCII, setiap aksara (angka, abjad dan simbol khas) diwakili oleh sejumlah 7 bit nombor perduaan yang terdiri daripada rentetan tujuh '0' atau '1'. Ia melibatkan sejumlah 128 aksara biasa dengan tambahan 128 aksara lanjutan.

“

Saya telah mengesahkan cadangan yang telah diberikan oleh Setiausaha Kewangan berkenaan dengan piawaian yang perlu diwujudkan semasa merakam Kod Piawai untuk kegunaan Perkongsian maklumat di atas pita magnetik dan pita kertas semasa digunakan di atas komputer. Semua komputer atau peralatan yang mempunyai konfigurasi yang hampir serupa yang di bawa masuk ke dalam senarai peralatan kerajaan Federal pada dan selepas 1 Julai 1969 hendaklah mempunyai kemampuan untuk menggunakan Kod Piawai untuk kegunaan Perkongsian maklumat dan format piawai untuk pita magnetik dan pita kertas jika bahan ini akan digunakan.

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.

BIT

Bit adalah gabungan perkataan binari dan digit yang membawa maksud digitperduaan, dan boleh mengambil nilai 0 atau 1. Sebagai contoh, nombor 10010111 adalah sepanjang 8 bit. Digit perduaan merupakan unit asas storanmaklumat dan komunikasi dalam bidang pengkomputan dan teori maklumatdigital. Teori maklumat juga menggunakan digit tabii yang dipanggil nat (ataunit). Pengkomputan kuantum pula menggunakan qubit, satu cebisan maklumat dengan kebarangkalian benar.

Bit juga merupakan unit ukuran, muatan maklumat satu digit perduaan. Simbolnya ialah bit, dan juga b (tidak rasmi). Unit ini juga dikenali sebagaishannon, dengan simbol Sh.

Kuantiti bit
Awalan SI			Awalan perduaan
Nama (Simbol)	Piawai SI	Jarang diguna	Nama (Simbol)	Nilai
kilobit (kb)	103	210	kibibit (Kibit)	210
megabit (Mb)	106	220	mebibit (Mibit)	220
gigabit (Gb)	109	230	gibibit (Gibit)	230
terabit (Tb)	1012	240	tebibit (Tibit)	240
petabit (Pb)	1015	250	pebibit (Pibit)	250
eksabit (Eb)	1018	260	eksbibit (Eibit)	260
zetabit (Zb)	1021	270	zebibit (Zibit)	270
yotabit (Yb)	1024	280	yobibit (Yibit)	280

current-and-future-development

1.4.1 Impact of ICT on Society

1.4.1.1 Locate information from various sources

Informations or study materials are available offline and online. We can search for the information that we want in books, journals, articles or other resource materials found in the library and the Internet. A list of all the books, journals and electronic materials are available from the library. We can use the online databases to find the most useful materials for our study.

1.4.1.2 Describe the impact of ICT on 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.

Education

Today, computers are used in schools, colleges and universities to promote better education. Students use software packages to complete their assignments. Educators use the computer-based training and web-based training as replacements for lecture presentation.

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.

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.

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. 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 and Perodua.

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.

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. We can access government websites to:

• check information on taxes (www.hasil.org.my)
• pay parking tickets and check summons (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 which 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

1.4.1.3 Present results in a clear, concise manner.

A good presentation should contain three well-defined sections, they are:

1. Introduction

• is at the beginning of the research
• includes the objectives of the research
• provides a clear statement on why the study was undertaken
• includes the limitations/assumptions and analytical techniques

2. Content

• consists of facts or arguments related to subject matter
• can be presented in an argument format or just as an overview

3. Conclusion

• is a review of content (not repetition of content)
• relates to the statement of objectives in the introduction
• should not introduce new issues
• should contain judgment or decision that has been reached

1.4.1.4 Display cooperation in conducting study.

Cooperation in conducting study can be display through delegation of works among team members. Delegation is the ability to assign tasks to others with the authority, responsibility and accountability to finish the tasks. This means it is not enough to just give out orders to people but as a team leader you also need to give specific instructions on what to do. Tell your team members that they are responsible for the task given to them and explain to them what would happen to the project if they failed to finish the task.

Qasidah Istighfar Lirik // Qasidah Istighfar Lyrics

Bahasa Arab Rumi // Arabic in Western writing

Astaghfirullah robbal baroya
Astaghfirullah minal khotoya (2x)

Robbi zidni i`lman nafia`
Wawafiqni a`malan maqbula
Wahabli rizqon wasia`
Watub a`laina taubatan nasukha (2x)

Astaghfirullah robbal baroya
Astaghfirullah minal khotoya

Walihaza sirri adu` fi yasari wa a`sari
Ana a`bdun soro faqri inna faqri waddhirori
Inna faqri waddhirori

Astaghfirullah robbal baroya
Astaghfirullah minal khotoya

Walkafani i`lmu robbi
Bil suali wakhtiyari
Ya Ilahi wa maliki
Anta ta`lam kaifa khali (2x)

Astaghfirullah robbal baraya
Astaghfirullah minal khotoya

computer security

1.3.1 Definition

 

1.3.1.1 Define computer security.

Computer security means protecting our computer systems and the information they contain against unwanted access, damage, destruction or modification. Three types of computer security are: hardware security software security/data security network security

We need to protect our computer from any intruders such as hackers, crackers and script kiddie.

1.3.2 Security Threats

1.3.2.1 Explain briefly the different threats to computer security:

Malicious code

Malicious code is also known as a rogue program. It will cause undesired effects in the programmer’s part. The effect is caused by an agent, with the intention to cause damage. The agent for malicious code is the writer of the code who causes its distribution. There are various kinds of malicious code. They include virus, Trojan horse, logic door, trapdoor and backdoor, worm and many others.

Hacking

Hacking is defined as unauthorised access to the computer system by a hacker. Hackers are persons who learn about the computer system in detail. They write program referred to as hacks. Hackers may use a modem or cable to hack the targeted computers.

Natural disaster

Computers are also threatened by natural or environmental disaster. Examples of natural and environmental disasters:

• Flood
• Fire
• Earthquakes, storms and tornados
• Excessive Heat
• Inadequate Power Supply
• Theft

Two types of computer theft:

1) Computer is used to steal money, goods, information and resources.

2) Stealing of computer, especially notebook and PDAs.

1.3.3.2

Apply the correct security procedures.

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

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. Tcpwrappers and tripwire are often used to detect any illegal access (unauthorize) to the 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 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 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

Computer systems would not allow any unauthorised users to simply access the system. Ways to prevent illegal access to systems: • Run anlpassword to make password cracking difficult. Run tcpwrappers to check if the name for an ip address can be provided by DNC 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 (stands for Superuser do) 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 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.