module ppt143

Diploma in Business management

MODULE

Information Technology in Business

PPT 143

Prepared by: Norliza Muhammad NorKPTM Kota Bharu

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Chapter 1: Introduction to computers

Objectives:

1. Recognize the importance of computer literacy2. Identify the components of a computer3. Discuss the uses of the Internet and World Wide Web4. Identify the categories of software5. Describe the categories of computers6. Identify the types of computer users7. Discuss various computer applications in society

Computer literacy:

Also known as a digital literacy Computer are everywhere :

o its is use at work, at school and at homeo example: mobile devices (cell phone), news, weather report, sport scores, airline

schedules, telephone directories, maps and directions, job listing, credits report, tutorial online, shares photo and video, files taxes, online shopping, email, book flights, share opinion.

Involves having a current knowledge and understanding of computers and their uses. The requirements of computer literacy changes as technology changes.

What is Computer?

Electronic device operating under the control of instructions stored in its own memory Computer can accept data, process the data according to specified rules then produces

results and store the results for future use.

Information processing cycle:


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Is a series of input, process, output, storage and communication activities Normally computer process data (input) into information (output) then its holds data,

information and instruction in storage for future use. Instruction is a step that tells the computer how to perform a particular task.

Advantages and Disadvantages of using computers:

Advantages:

1. Speed: when data, instruction and information flow along electronic circuits in a computer, they travel at incredibly fast speeds. Many computers process billions or trillions of operations in a single second.

2. Reliability: the electronic components in modern computers are dependable and reliable because they rarely break or fail.

3. Consistency: Given the same input and processes, a computer will produce the same results.

4. Storage: computers store enormous amounts of data and make this data available for processing anytime it is needed.

5. Communications: most computers today can communicate with other computer, often wirelessly.

Disadvantages:

1. Violation of privacy: where personal and confidential records were not protected properly, this privacy can be violated and stolen.

2. Public safety: Adults, teens, and children around the world are using computers to share publicly their photos, videos, journals, music and other personal information. Some of these u suspecting, innocent computer users have fallen victim to crimes committed by dangerous strangers.

3. Impact on labor force: Although computers have improved productivity and created an entire industry with hundreds of thousands of new jobs, the skills of millions of employees have been replaced by computers.

4. Health risk: prolonged or improper computer use can lead to health injuries or disorders. Computer users can protect themselves from health risks through proper workplace design, good posture while at the computer and appropriately spaced work


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breaks. Another health risk. Called computer addiction, occurs when someone becomes obsessed with using the computer.

5. Impact on environment: computer manufacturing processes and computer waste are depleting natural resources and polluting the environment. Strategies that can help protect the environment include recycling, regulating manufacturing processes, extending the life of computers and immediately donating replaced computers.

The components of a computer

A computer contains many electric, electronic and mechanical components known as HARDWARE.

These components include input devices, output devices, a system unit, storage devices and communications devices.

Input devices:

Any hardware that allows user to enter data and instructions into a computer Example: keyboard, mouse, microphone, scanner, digital camera and web cam.

Output devices:

Hardware component that conveys information to one or more people. Example: printer, monitor, speaker and portable media player.

System unit:

Is a case that contains electronic components of the computer used to process The data. The circuit of the system unit usually is part of or is connected to a circuit board called

the motherboard Example of component in system unit: motherboard, RAM, ROM, battery, floppy disk,

hard disk etc.

Storage devices:

Storage hold data, instructions and information for future use and permanently Storage device records (write/ reads) items to and from storage media.


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( storage media: physical material on which data, instruction and information are stored such as USB flash drives, hard disk, CDs, DVDs an d memory card)

Storage device often function as a source of input because they transfer items from storage to memory.

USB flash drive:

o Is a portable storage device that is small and lightweight enough to transported on a keychain or in a pocket.

o Its can hold about 2 billion characters.

Hard disk:

o Can hold more than 320 billion characters.o Much greater storage capacity than a USB flash drive.o Can use either inside of system unit or portable (external and removable).

CD:

o Hold data from 650 million to 1 billion characterso Can access using CD and DVD drives.

DVD:

o Store two full-length movies or 17 billion characters.o Can access using DVD drive.

Memory card:

o Use card reader/ writer to transfer stored item such as digital photos.

Communication devices:

o Is a hardware component that enables a computer to send (transmit) and receive data, instruction and information to and from one or more computers.

o Example: modemo Communications occur over cables, telephone lines, cellular radio networks,

satellites and other transmission media.


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Network and Internet

A network is a collection of computers and devices connected together, often wireless, via communications devices and transmission media.

Network allow computers to share resources, hardware, software, data and information.

The internet is a world wide collection of networks that connects millions of business, government agencies, educational institutions and individuals.

People use internet for:o Communicationo Get and share informationo Shoppingo Banking and investingo Classeso Entertainmento Download music, video and etc.

Web (World wide web) is a popular services on the internet. Its contains billions of documents called web pages.

Web page is a document that contain text, graphics, audio and video. Web site is a collection of related web pages. Social networking web site encourage members to share their interests, ideas, stories,

photos, music and video with other registered users. Blog is an informal web site consisting of time-stamped articles in a diary or journal

format. Podcast is recoded audio stored on a web site that can be downloaded to a computer or

a portable media player such as ipod.

Computer Software

Also called a program Is a series of instructions that tells the computer what to do and how to do it. Software today often has a graphical user interface (GUI).


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With GUI: o its allow us to interact with the software using text,graphics and visual image

such as icons.o An icon is a miniature image that represents a program, an instruction or some

other object.o We ca use mouse to select the icons to performs the operations.

2 categories of software areo System softwareo Application software

System software:

Consists of the program that control or maintain the operation of the computer and its devices.

System software serves as the interface between the user, the application software and the computers hardware.

2 types of system software:o Operating system

Is a set of programs that coordinates all the activities among computer hardware devices.

Example: Microsoft OS (windows vista, windows XP), Apple OS( Mac OS X)

When we start a computer, portions of the OS load into memory from the computer’s hard disk.

Its remains in memory while the computer is on.o Utility program

Allows a user to perform maintenance type tasks usually related to managing a computer, its devices or its program.

Example: use to transfer digital photos to a CD or DVD, managing disk drivers, printers and other devices or media

Application software:

Consists of program designed to make users more productive and assist them with personal tasks.

Example: word processing, spreadsheet, database and presentation software.


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Categories of a computer:

7 categories o Personal computer/ desktopo Mobile computer/ mobile deviceso Game consoleso Serverso Mainframeso Supercomputerso Embedded computers

Personal computer/ desktop:

o Can perform all of its input, processing, output and storage activities by itself.o Contains a processor, memory and one or more input, output , storage and

communications deviceso 2 popular styles of personal computer are : PC (use OS windows-IBM design)

and Apple computers (use Macintosh OS)o 2 types of Personal Computer are : desktop and notebook computer.

Desktop: is designed with the system unit, input devices, output devices and any

other devices fit entirely on or under a desk or table.

Notebook:

Also called as a laptop computer. Is portable, personal computer designed to fit on your lap. More expensive than desktop with equal capabilities. Weigh from 2.5 to more than 10 pounds. Can operate on batteries or power supply or both.

Mobile computers:

o Is a personal computer can be carry from place to place such as notebook and tablet PC


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Tablet PC: Is a special type of notebook computer that allows us to write or draw on

the screen using digital pen We can attach a keyboard to Tablet PC. Useful especially for taking notes in locations where the standard

notebook computer is not practical. Widely used in medical and legal communities.

Mobile devices:

Small & can carry in a pocket. Stores program and data permanently on memory inside the system unit

or on small storage media such as memory card. Can connect to a personal computer to exchange information. Some mobile device are internet enabled, meaning they can connect to

the internet wirelessly. 3 types:

Handheld computero Referred to as Ultra-Mobile PC (UMPC)o Small and can fit in one hand.o The screens are small

PDAso Personal digital assistanto Provides personal organizer functions such as calendar,

appointment book, address book, calculator and notepado Are internet enabled so users can access to the webo Have a camera and phone capabilitieso Also function as a portable media player.o Input device use stylus ( like a small ballpoint pen, but use

pressure instead of ink to write and draw). Smart Phone

o Is an internet enabled phone that provides PDA capabilities.

o Its allow a user to send and receive e-mail message and access the web (with a fee)

o Simply as handhelds.


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Games consoles:

Is a mobile computing device designed for single player or multiplayer video games.

Standard game consoles use handheld controller as an input devices, a television screen as output device and hard disks, CD,DVD and memory card for storage.

3 popular model are:o Microsoft Xbox 360o Nintendo’s Wii o Sony’s PlayStation 3.

A handheld game console is small enough to fit in one hand. Many handheld game console can communicate wirelessly with other

similar consoles for multiplayer gaming.

Servers:

Use to control access to the hardware, software and other resource on a network and provide a centralized storage area for programs, data and information.

Its support from 2 to several thousand connected computer at the same time.

People use personal computer or terminal (a device with a monitor, keyboard and memory) to access data, information and programs on a server.

Mainframes:

Is a large, expensive and powerful computer that can handle hundreds or thousands of connected users simultaneously.

Its store huge amount of data, instructions and information. Most major corporations use mainframe for business activities.


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With mainframe, large business are able to bill millions of customers, prepare payroll for thousands of employees, and manage thousands of items in inventory.

Its process more than 83 percent of transaction around the world. Server and other mainframes can access data and information from a

mainframe. People can access programs on the mainframe using terminals or

personal computers.

Supercomputers:

The fastest, most powerful computer and most expensive. Can process more than 135 trillion instructions in a single second. Use for large scale simulations, application in medicine, aerospace,

automotive design, online banking, weather forecasting, nuclear energy research and petroleum exploration.

Its use complex and sophisticated mathematical calculations applications.

Embedded computers:

A special purpose computer that functions as a component in a large product.

Use in consumer electronics, home automation devices, automobiles, process controllers / robotics and computer device/ office machines.

Computer application in society:

Computer has changed society today as mush as the industrial revolution changed society in the eighteenth and nineteenth centuries.

People interact directly with computers in fields:o Education

Online note and tutorial Access school network / internet wirelessly

o Finance Online banking Online investing (buy and sell stocks and bonds without using a broker)

o Government Provide citizens with up-to date information


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Have a offices web site to file taxes, apply for permits and licenses, pay parking tickets, buy stamps, report crimes, apply for financial aid, renew vehicle registrations and driver’s licenses.

o Health care Doctor use the web and medical software to assist with researching and

diagnosing health conditions. Doctor use e-mail to correspond with patients. Pharmacists use computer to file insurance claims. Robots can deliver medication to nurse stations in hospitals. Computers and computerized devices assist doctors, nurses, and

technicians with medical test.

o Science Computer use for collecting, analyzing and modeling data Scientists use the internet to communicate with colleagues around the

world.

o Publishing Special software assists graphic designers in developing pages that

include text, graphics, photos, artists in composing and enhancing songs, film markers in creating and editing film, journalists and mobile user in capturing and modifying video clips.

These works include books, magazines, newspaper, music, film and video. Some of the publisher makes their works available online.

o Travel Use for order airline tickets on the web, print directions and a map from

the web.

o Manufacturing Computer-aided manufacturing (CAM) refers to the use of computers to

assist with manufacturing processes such as fabrication and assembly. Robot carry out processes in a CAM environment CAM is used by a variety of industries, including oil drilling, power

generation, food production and automobile manufacturing.


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Chapter 2: Application software

Application software

With the proper software, a computer is a valuable tool Software allows user to create letter, report, design web pages, draw images, enhance

audio and video clips, prepare taxes, play games, compose e-mail, instant message and much more.

Application software consists of program designed to make users more productive and assist them with personal tasks.

Application software are uses :o To make business activities more efficiento To assist with graphics and multimedia projectso To support home, personal and educational taskso To facilitate communications

4 categories of application software and utility programs are:


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Application software is available or distributed in a variety of form :

o Packaged software Is mass- produced Copyrighted retail software that needs of a wide variety of users(single

user or company) Example Microsoft office 2007 Is available in retail stores or on web

o Custom software Perform functions specific to business or industry. The company may use programmers to develop tailor-made custom

software


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Example : sistem pengiraan markah pelajar

o Web base software Programs hosted by a web site User access and interact with web based software from any computer or

device that connect to the internet. Example: e-mail, game programs.

o Open source software Software provided for use, modification and redistribution. This software has no restrictions from the copyright holder regarding

modification of the software’s internal instructions and redistribution of the software.

Open source software usually can be downloaded from the internet, sometimes at no cost.

o Shareware Is copyright software that is distributed at no cost for a trial period. To use a shareware program beyond that period, you need to send

payment to the program developer.

o Freeware Is copyright software provided at no cost to a user by an individual or a

company that retains all rights to the software.

o Public domain software Has been donated for public use and has no copyright restrictions. Anyone can copy or distribute public-domain software to others at no

cost.

Business software

Is application software that assists people in becoming more effective and efficient while performing their daily business activities.


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The popular business program :

Graphics and multimedia software


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The popular software for graphics and multimedia are:

Software for home, personal and educational use


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Application software Manufacturer Program nameSoftware suite Microsoft Works

sun OpenOffice.orgPersonal Finance Intuit Quicken

Microsoft moneyLegal Broderbund Home and business lawyer

will writerCosmi Perfect attorneyNolo Quicken legal business

quicken will makerTax Preparation 2nd story software TacACT

H & R Block TaxCutIntuit Turbo Tax

Desktop Publishing Broderbund The Print ShopPrintmaster

Microsoft Publisher 2007Paint/ image editing Corel CorelDRAW

The GIMP Team The GimpPhoto editing and photo management

Adobe Photoshop elementsCorel Paint shop pro photo

Ulead photoimpactUlead Photo Express

Google PicasaMicrosoft Photo storyRoxio Photo Suite

Clip art/ image gallery Broderbund ClickArtNova Development Art Explosion

Video and audio editing Corel Ulead VideoStudioMicrosoft Movie makerPinnacle systems Studio MovieBoxRoxio VideoWave

Home design/ landscaping Broderbund Instant ArchitectBetter Homes & gardensHome Designer

Travel and mapping DeLorme Street AtlasMicrosoft Streets & Trips

reference Fofware Publishing Merriam-WebsterCollegiate Dictionary & Thesaurus

Microsoft Encarta


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Learning aids and support tools for application software

Learning how to use application software effectively involves time and practice. To assist in the learning process, many programs provide online Help and Web-based

Help.

Online Help

Is the electronic equivalent of a user manual. Its usually is integrated in a program. We use the Help feature to ask a question or access the help topic in subject

or alphabetical order. Most online help also links to web site that offer web-based help, which

provides updates and more comprehensive resources to respond to technical issues about software.

Some web site contain chat room, in which a user can talk directly with a technical support person.

Web-based Trainning

Is a type of CBT (computer based training) that uses internet technology and consists of application software on the web.

WBT typically consists of self-directed, self-paced instruction about a topic. WBT is popular in business, industry and schools for teaching new skills or

enhancing existing skills of employees, teachers or students. WBT is combined with other materials for distance learning and e-learning. Distance learning is the delivery of education at one location while the

learning takes place at other locations. E-learning, short for electronic learning is the delivery of education via some

electronic method such as the internet, networks, CDs/DVDs. E-learning system also may include video conferencing, e-mail, blogs, wikis,

newsgroups, chat rooms and groupware.


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Chapter 3: System software, operating systems and utility programs

System software

Consists of programs that control or maintain the operations of the computer and its devices.

Its serves as the interface between the user, the application software and the computer’s hardware.

2 types of system software:o Operating systemo Utility programs

Operating systems (OS)

Is a set of programs containing instructions that work together to coordinate all the activities among computer hardware resources.

Function of OS includes:o Starting a computero Provide a user interfaceo Managing programso Managing memoryo Coordinating tasks.o Configuring deviceso Establishing an internet connectiono Monitoring performanceo Providing file management utilities.

Also allow users to control a network and administer security The OS is installed and resides on the computer’s hard disk. For handheld computer and mobile devise, the OS may reside on a ROM chip. Different size of computer normally uses different Operating system. When we purchasing application software, we must ensure its work with the OS

installed on our computer. We also can call Operating system as a platform. We can install more than one OS in one computer.


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Operating system functions


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1. Starting a computer Booting is the process of starting or restarting a computer. When turning on a computer that has been powered off completely. You

are performing a Cold Boot. A worm boot is the process of using the OS to restart a computer.

Each time we boot a computer, the kernel and other frequently used OS instruction are loaded or copied from the hard disk into the computer memory (RAM)

The kernel is the core of an OS that manages memory and device, maintains the computer’s clock, start programs, data and information.

The kernel is memory residents, which means it remains in memory while the computer is running, other parts of the OS are nonresident, that is, these instructions remain on hard disk until they are needed.

2. Provide a user interface User interface control how to enter data and instructions and

information is displayed on the screen. 2 types of user interface:

Command line(Configure devices, manage system resources and troubleshoot network)

graphical OS use a combination of this interface to define how a user interacts with

computer.

3. Managing programs Some OS support a single user and only run a program at a time and

some of them support Thousands of users and running multiple programs at a time.

Smart phones and personal mobile device use single user & single tasking OS.

A single user/ multitasking OS allows a single user to work on 2 or more program that resides in memory at a time

4. Managing memory/ memory management Is used to optimize the use of random access memory (RAM)


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Ram consists of one or more chips on the motherboard that hold items such as data and instruction while the processor interprets and execute them.

The OS allocates or assigns data and instruction to an area of memory while they are being processed. Then it carefully monitors the contents of memory and finally OS releases these items from being monitored in memory when the processor no longer requires them.

Virtual memory is a concept in which the OS allocates a portion of a storage medium (usually hard disk), to work as a additional RAM.

OS use area of hard disk for virtual memory to swaps (exchanges) data, information and instructions between memory and storage and we call its as a paging.

5. Coordinating tasks. The operating system determines the order in which tasks are processed.

A task or job is an operation the processor manages. Tasks include receiving data from an input device, processing instructions, sending information to an output device and transferring items from storage to memory and from memory to storage.

A multi-user operating system does not always process tasks on a first come, first served basic. Sometimes, one user may have a higher priority than other users. In this case, the operating system adjusts the schedule of tasks.

Sometimes, a devices already may be busy processing one task when it receives a second task. This occurs because the processor operates at mush faster rate of speed then peripheral devices. For example, if the processor sends five documents to a printer, the printer can print only one document at a time and store as many documents as its memory can handle.

While waiting for device to become idle, the operating system places items in buffers. A buffer is a segment of memory or storage in which items are places while waiting to be transferred from an input device or to an output device.

The operating system commonly uses buffer with printer documents. This process, called spooling, sends documents to be printed to a buffer instead of sending them immediately to the printer.

The buffer holds the information waiting to print while the printer prints from the buffer at its own rate speed. By spooling documents to a buffer,


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the processor can continue interpreting and executing instructions while the printer prints. This allows users to work on the computer for other tasks while a printer is printing.

Multiple print job line up a queue in the buffer. A program, called a print spooler, intercepts documents to be printed from the operating system and places them in the queue.

6. Configuring devices A driver is a small program that tells the operating system how to

communicate with a specific device. Each device on a computer, such as the mouse, keyboard, monitor, printer and scanner has its own specialized set of commands and thus requires its own specific driver. When we boot a computer, the operating system loads each devices driver.

If we attach a new device to a computer, its driver must be installed before we can use the device. For many devices, the computer’s operating system includes the necessary driver, if it does not, we can install the drivers from the CD provided with the purchased device.

Today, many devices and operating systems support Plug and Play, Plug and Play means the operating system automatically configures new devices as you install them. With plug and play, a user can plug in a device , turn on the computer and them use the device without having to configure the system manually.

7. Establishing an internet connection Operating system typically provides a means to establish internet

connection. For example, windows vista includes a ‘connect a network’ wizard that guides users through the process of setting up a connection between a computer and an internet access provider.

Some operating systems also include a web browser and e-mail program, enabling user to begin using the web and communication with others as soon as user set up the internet connection.

Some also include utilities to protect computers from unauthorized instructions and unwanted software such as viruses and spyware.


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8. Monitoring performance Operating system typically contains a performance monitor. A

performance monitor is a program that accesses and report information about various computer resources and device.

The information in performance reports help users and administrators identify a problem with resources so that they can try to resolve any problem. If a computer is running extremely slow, for example, the performance monitor may determine that the computer memory is being used to its maximum. Thus, you might consider installing additional memory in the computer.

9. Providing file management utilities. Operating system often provide users with the capability of managing

files, searching for files, viewing images, securing a computer from unauthorized access, uninstalling programs, scanning disks, defragmenting disks, diagnosing problems, backing up file and disks and setting up screen savers.

10. controlling a network some operating system are network operating systems. A network

operating system or network OS is an operating system that organizes and coordinates how multiple users access and share resources on a network. Resources include hardware, software, data and information.

Some operating system has features built into them. In other case the network OS is a set of programs separate from the operating system on the network, the client computers use their own operating system. When connected to the network, the network OS may assume some of the operating system functions.

The network administrator, the person overseeing network operations, uses the network OS to add and removes users, computers and other devices to and from the network.

The network administrator also uses the network operating system to install software and administer network security.


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11. administering security the network administrator uses the network OS to establish permissions

to resources. These permissions define who can access certain resources and when they can access those recourses.

For each user, the network administrator establishes a user account, which enables a user to access, or log on to a computer or a network. Each user account typically consists of a user name and password.

A user name or user ID is a unique combination of characters such as letter or numbers.

A password is a private combination of characters associated with the user name that allows access to certain computer resources. Some operating system allows the network administrator to assign password to files and command, restricting access to only authorized users.

To prevent unauthorized user from accessing computer recourses, keep your password confidential. While entering your password, most computer hide the actual password characters by displaying some other characters such as asterisks (*) or dots.

After entering a user name and password, the operating system compare the user’s entry with a list of authorized user name and password. If the entry does not match, the operating system denies access to the user.

To protect sensitive data and information as it travels over the network, a network operating system may encrypt it.

Encryption is the process of encoding data and information into an unreadable form.

Network administrators can set up a network to encrypt data as it travels over the network to prevent unauthorized users from reading the data. When an authorized user attempts to read the data, it automatically is decrypted or converted back into a readable form.


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Utility program

also called as a operating system utility programs. Is a type of system software that allows a user to perform maintenance-type task

(such as managing a computer, its devices or its programs). Most OS include several built in utility program and some of them buy by user

(stand alone utility). Example:

o File managero Search utilityo Image viewero Personal firewallo Uninstallero Disk scannero Disk defragmentero Diagnostic utilityo Backup utilityo Screen server.

Types of operating systems

Category Operating system nameStand alone

Is a complete OS that works on a desktop, notebook or mobile device.

Some of them are called as client operating system

DOS Early windows versions (windows 3.X,

windows 95, windows NT workstation, windows 98, windows 2000 professional, windows millennium edition)

Windows xp Windows vista Mac OS x UNIX Linux

Network

Is designed specifically to support network.

Typically resides on a server

Early windows server versions (Windows NT server, windows 2000 server, windows server 2003)

Windows server 2008 UNIX Linux


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Solaris Netware

Embedded

OS on most smart phones and small device.

Resides on a ROM chip.

Windows Embedded CE Windows mobile Palm OS Embedded Linux Symbian OS


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Chapter 4: The components of the system unit

The system unit

Is a case that contains electronic components of the computer used to process data. Are available in a variety of shapes and size The case of the system unit is made of metal or plastic and its protects the internal

components from damage. All computers have a system unit Common components inside the system unit:

o Processoro Memoryo Adapter card

Sound card Video card

o Drive bayso Power supplyo Motherboard/ circuit board

Motherboard:

Also called as a system board The main circuit board of the system unit Many electronic components attach to the motherboard (built in) such as expansion

slots, processor chip, memory slots Memory chips are installed on memory cards that fit in a slot on the motherboard. A computer chip is a small piece of semiconducting material, usually silicon on which

integrated circuit electrical current. Each integrated circuit can contain millions of elements such as resistors, capacitors and transistors.

Processor

Also called the central processing unit (CPU) Interprets and carries out the basic instructions that operate a computer. On a personal computer, all functions of the processor usually are on a single chip and

normally called as a microprocessor. Most processor chip manufacturers now offer multi core processors.


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Multi-core processor is a chip with 2 or more separate processors. 2 common multi-core processor used today are

o Dual- core ( is a chip that contains 2 separate processors)o Quad-core (is a chip with four separate processors)

Multi-core chip runs at a slower clock speed than a single-core processor, but multi-core chips typically increase overall performance.

Processor contain : o Control unit (CU)o Arithmetic logic unit (ALU)

CU and ALU work together to perform processing operations.

The Control Unit:o The component of the processor that directs and coordinates most of the

operations in the computer.


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o Has a role much like a traffic cop: it interprets each instruction issued by a program and then initiates the appropriate action to carry out the instruction.

The Arithmetic Logic Unit:o Performs arithmetic (addition, subtraction, multiplication and division),

comparison( comparing one data item with another such as equal to or less than), and other operations.

Machine cycle:o The steps involves:

1. Fetching2. Decoding3. Executing4. Storing


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The system clock:o To control the timing of all computer operations.o Its generates regular electronic pulses or ticks that set the operating pace of

components of the system unit.o Clock speed is measured by the number of ticks per second.o Current personal computer processors have clock speeds in the gigahertz range.

Comparison of personal computer processor:o Types of processor used are Intel, AMD (Advanced Micro Devices), IBM and

Motorolao Intel:

- Used a model number to identify the various chips. After learning that processor model numbers could not be trademarked and protected from use by competitors.

- Intel began identifying its processors with names.- Most high performance desktop PCs today use a processor in the Intel

core family.- Less expensive, basic PCs today use a brand of Intel processor in the

Pentium or Celeron family.- The Xeon and Itanium families of processors are ideal for workstations

and low-end servers.

o AMD:- Is the leading manufacturer of Intel-compatible processors. Which have

an internal design similar to the Intel processor.- Less expensive.

o Apple computer used only an IBM processor or Motorola Processor, which had a design different from the Intel-style processor.


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Data representation

To understand the way a computer processes data, we should know how a computer represents data.

Most computer are digital. The recognize only 2 discrete states ( ON and OFF). The digit 0 represents the electronic state of OFF and digit 1 represents the electronic

state of ON. The computer uses a binary system because it recognizes only 2 states. The binary system is a number system that has just 2 unique digits 0 and 1 called bits. A bit (short for binary digit) is the smallest unit of data the computer can process. When 8 bits are grouped together as a unit, they form a byte. A byte provides enough different combination of 0 and 1 to represent 256 individual

characters. These characters include numbers, uppercase and lowercase letters of the alphabet,

punctuation marks and other such as the Greek alphabet. The combinations of 0 and 1 that represent characters are defined by patterns called a

CODING SCHEME. 2 popular coding scheme are:

ASCII (American standard code for information interchange) EBCDIC (Extended Binary Coded Decimal Interchange code: use in mainframe

and high-end server) Example :

Symbol ASCII EBCDIC0 00110000 111100001 00110001 111100012 00110010 11110010A 01000001 11000001B 01000010 11000010C 01000011 11000011! 00100001 01011010# 00100011 01111011& 00100110 01010000+ 00101011 01001110


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How a letter is converted to binary form and back


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Memory

Consist of electronic components that store instructions waiting to be executed by the processor. Data needed by those instructions and the result of processed data (information).

Memory Usually consists of one or more chips on the motherboard or some other circuit board on the computer.

Memory stores 3 basic categories of items: The operating system and other system software that control or maintain the

computer and its device. Application programs that carry out a specific task such as word processing. The data being processed by the application programs and resulting information.

A byte (character) is the basic storage unit in memory. Terms commonly used to define memory size are:

Term Abbreviation Approximate Number of

Bytes

Exact Amount of bytes

Approximate Number of

Pages of TextKilobyte KB or K 1 thousand 1,024 ½Megabyte MB 1 million 1,048,576 500Gigabyte GB 1 billion 1,073,741,824 500,000Terabyte TB 1 trillion 1,099,511,627,776 500,000,000

2 types of memory: Volatile

Temporary memory When the computer’s power is turned off , volatile memory loses its

contents. Example : RAM

Nonvolatile Is permanent memory Does not lose its contents when power is removed from the computer. Example: ROM, flash memory and CMOS

RAM: Stand for random access memory Also called as a main memory


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Its consists of memory chips that can be read from and written to by the processor and other divice.

When we turn on power to a computer, certain OS files load into RAM from a storage devices such as hard disk. These files remain in RAM as long as the computer has continuous power, some of additional programs and data are requested also load into RAM.

Ram can hold multiple programs simultaneously. Most of RAM is volatile, which means it loses its contents when the power is

removed from the computer. Saving is the process of copying items from RAM to storage devices such as a

hard disk. 3 basic types of RAM chips are:

o Dynamic RAM DRAM pronounced DEE-ram Chips must be re-energized constantly or they lose their contents.

o Static RAM SRAM pronounced ESS-ram Chips are faster and more reliable than any variation of DRAM

chips. These chips do not have to be re-energized as often as DRAM

chips.

o Magnetoresistive RAM A new types of RAM MRAM pronounced EM-ram Store data using magnetic charges. Has greater storages capacity, consumes less power and has

faster access times than electronic RAM. Ram chips usually reside on a memory module in memory slots on the

motherboard. The more RAM a computer has, the faster the computer will respond.

o Example: Run windows vista and using basic application software ( word

processing) – at least 1GB RAM For accounting, financial, spreadsheet programs and multimedia –

1 until 4 GB of RAM. Creating professional web site or using graphics – 4GB or more


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The amount of RAM in computer purchased today ranges from 1GB to 64 GB. Cache:

Most of today’s computers improve processing times with cache. 2 types of cache memory are: memory cache and disk cache. Memory cache helps speeds up processing time by storing frequently used

instruction and data. 2 types of memory cache are:

L1 cache Built into processor Has a small capacity(8 KB to 128 KB)

L2 cache Slower but has larger capacity (64KB to 16MB) L2 advanced transfer cache is faster and built directly on

processor chip (512 KB to 8 MB)

When the processors need an instruction or data, it searches memory in this order: L1 cache, then L2 cache then RAM. If the instruction or data is not found in memory, then it must search a slower speed storage medium such as hard disk, CD or DVD.

ROM: Stand for READ ONLY MEMORY Store data and instruction permanently The data on most ROM chips cannot be modified ROM is nonvolatile, which means its contents are not lost when power is

removed from the computer. Manufacturers of ROM chips often record data, instruction or information on the

chips when they manufacture the chips. These ROM chips called FIRMWARE, that contain permanently written data,

instruction and information.

Flash memory: Is a type of nonvolatile memory that can be erased electronically and rewritten. Most computer use flash memory to hold their startup instructions because it

allows the computer easily to update its contents. Used in smart phones, portable media player, PDAs, printers, digital cameras,

automotive devices, digital voice recorders and pagers.


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CMOS: Some RAM chips, flash memory chips and other types of memory chips use

complementary metal oxide semiconductor (CMOS) technology because it provides high speeds and consumes little power.

CMOS technology uses battery power to retain information even when the power to computer is off.

Memory access times: Is the amount of time it takes the processor to read data, instructions and

information from memory. Accessing data in memory can be more than 200,000 times faster than accessing

data on hard disk because of the mechanical motion of the hard disk.

Expansion slots and adapter cards

An expansion slot is a socket on the motherboard that can hold an adapter card. An adapter card sometimes called an expansion card, is a circuit board that enhances

functions of component of the system unit and/ or provides connections to peripherals. A peripheral (modems, disk drives, printers, scanners and keyboards) is a device that

connects to the system unit and is controlled by the processor in the computer. Types of adapter card are:


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Some motherboard includes all necessary capability and do not require adapter card and some of them may require adapter card to provide capabilities such as sound and video.

A sound card enhances the sound generating capabilities of a personal computer by allowing sound to be input through a microphone and output through external speakers or headphones.

A video card or graphics card, convert computer output into a video signal that travels through a cable to the monitor, which display an image on the screen.

Port and connectors

A port is the point at which a peripheral attaches to or communicates with system unit so that the peripheral can send data to or receive information from the computer.

An external device such as a keyboard, monitor, printer, mouse and microphone often attaches by a cable to a port on the system unit.

Instead of port, the term jack sometimes is used to identify audio and video ports. The front and back of the system unit contain many ports.


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A connector joins a cable to a port. A connector at one end of cable attaches to a port on the system unit and at the other

end of the cable attaches to a port on the peripheral. Desktop personal computers may have a serial port, a parallel port, USB port and a

FireWire port.

Serial ports:

Is a type of interface that connect a device to the system unit by transmitting data one bit at a time

Usually connect devices that do not require fast data transmission rate such as mouse, keyboard or modem

Example COM port (short for communication port)


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Diagrams:

Parallel ports:

Is an interface that connects devices by transferring more than one bit at a time. Were developed as an alternative to the slower speed serial ports such as used to

connect a printer. This parallel port can transfer eight bits of data (1 byte) simultaneously through 8

separate lines in a single cable. Diagrams:


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USB ports:

Short for universal serial bus port. Can connect up to 127 different peripheral together with a single connector. Personal computer have 6 to 8 USB ports on the front and back of the system unit. The latest version of USB called USB 2.0 is a more advanced and faster USB with speeds

40 times higher than its predecessor. Device that connect to a USB port

o Mouse, printer, digital camera, scanner, speakers, portable media player, CD, DVD, smart phone, PDA, game console and removable hard disk.

To attach multiple peripheral using a single port, we can use a USB hub. USB hub is a device that plugs in a USB port on the system unit and contains multiple

USB ports in which you plug cables from USB devices.

FireWire ports:

Previously called an IEEE 1394 port. Similar to a USB port. Io can connect multiple types of devices that require faster data transmission speeds

such as digital video camera. Digital VCRs, color printers, scanners, digital camera and DVD drivers to a single connector.

A FireWire port allows you to connect up to 63 devices together. The latest version called FireWire 800. We can use a FireWire hub to attach multiple devices to a single FireWire port

Special purpose ports:

These ports are not included in typical computers. 5 special-purpose port are: MIDI, eSATA,SCSI,IrDA and Bluetooh.

Power supply

The power supply is the component of the system unit that converts the wall outlet AC power into DC power.

Some external peripheral such as a cable modem, speakers or printer have an AC adapter which is an external power supply that converts AC power into DC power.


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Mobile computer and device

Mobile computers and devices have a motherboard that contains electronic components that process data.

Notebook computer may have video, modem, network, FireWire, USB, headphone and microphone ports.

Some mobile users prefer connecting peripherals to a port replicator( an external device that attach to mobile computer, provides connections to peripherals through ports built into the replicator).

Mobile devices have an IrDA port or Bluetooth so users can communicate wirelessly with other computer or devices such as a printer.


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Chapter 5: Input and Output

What is an input and input devices

Input is any data and instructions entered into the memory of a computer. Input device is any hardware component that allows user to enter data and instructions

into a computer. Variety of input devices uses:

1. Keyboard2. Mouse (optical mouse, air mouse)3. Trackball4. Touchpad5. Pointing stick6. Light pen7. Gamepads8. Light guns9. Dance pads10. Touch screen11. Stylus (pen input)12. Graphics tablet13. Game controller14. Joystick15. Touch sensitive16. Microphone17. Digital camera18. Web cam19. Scanner20. Optical mark and character recognition21. Bar code readers22. RFID reader23. Magnetic stripe card readers24. MICR25. Biometric devices.


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What is output and output devices

Output is a data that has been processed into a useful form. 4 basic categories of output are : text, graphics, audio and video Output devices: is any hardware component that conveys information to one or more

people. Example of output device:

1. Printers2. Speakers3. Headphones4. Earphones5. Fax machines / fax modems6. Multifunction peripherals7. Data projectors8. Interactive whiteboards.


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Chapter 6: Secondary Storage

Storage

Storage hold data, instruction and information for future use. The usage of storage:

o At home: store letters, budgets, bank statements, household inventory, stock purchase, tax data, address, daily schedules, email messages, assignments, recipes, digital photos, music and video.

o In business: customer order, invoices, vendor payments, payroll records, tax data, inventory records, presentations, digital photo, contracts, marketing literature, appointments and web pages.

o Other: drawing, application software, OS, blueprints, product catalogs

Storage medium or secondary storage is the physical material on a computer to keeps data, instructions and information.

Example of storage medium are:o Hard disk (internal, external and miniature), CDs, DVDs, PC cards, Expresscard

modules, flash memory cards, USB flash drives, smart cards and microfilm.


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

Writing is the process of transferring data, instruction and information from memory to a storage medium.

Reading is the process of transferring these items from a storage medium into memory. When storage devices write data on storage media, they are creating output and when

storage devices read from storage media, they function as a source of input. The speed of storage devices is defined by access time. Access time measures the amount of time it takes a storage device to allocate an item

on a storage medium. The access time of storage devices is slow compared with the access time of memory.

Storage devices, access time in thousandths of a second (milliseconds) or millionths of a second (microseconds)

The number of bytes (characters) can be store/hold in storage medium was called as a CAPACITY.

The table below shown the capacity of a storage medium:

Storage term Approximate number of bytes

Exact number of bytes

Kilobyte (KB) 1 thousand 1024Megabyte (MB) 1 million 1048576Gigabyte (GB) 1 billion 1073741824Terabyte (TB) 1 trillion 1099511627776Petabyte (PB) 1 quadrillion 1125899906842624Exabyte (EB) 1 quintillion 1152921504606846976Zettabyte (ZB) 1 sextillion 1180591620717411303424Yottabyte (YB) 1 septillion 1208925819614629174706176


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Magnetic disk

Use magnetic particles to store items such as data, instruction and information on a disk’s surface.

Its represent either a 0 bit or 1 bit. Magnetic disks store data and instruction in track and sectors. A track is a narrow recording band that forms a full circle on the surface of the disk. The disks storage locations consist of pie shaped section, which break the track into

small arcs called sectors. A sector typically stores up to 512 bytes of data. A component used type of magnetic disk is hard disk. Some of magnetic disk are portable (can remove from one computer and carry it to

another computer) and some of them are not

Hard disk: INTRODUCTION


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Sector

Track

Cluster


Is a storage device that contains one or more inflexible, circular platters that store data, instruction and information.

The device is enclosed in an airtight, sealed case to protect it from contamination. A hard disk is mounted inside the system unit is called fixed disk. Current personal computer hard disks have storage capacities from 160 GB to 1 TB and

more. Hard disk store data using:

o Longitudinal recording: Aligned the magnetic particles horizontally around the surface of the disk.

o Perpendicular recording: Align the magnetic particles vertically or perpendicular to the disk’s

surface, making much greater storage capacities possible. Provide storage capacities 10 times greater than longitudinal recording

Hard disks are read/write storage media.


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Hard disk:

CHARACTERISTICS

Hard disk: HOW IT WORK


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Hard disk: EXTERNAL AND REMOVABLE


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Hard disk : CONTROLLERS

ONLINE STORAGE:

Optical disk


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A type of optical storage media that consist of a flat, portable, disc made of metal, plastic and lacquer.

These discs usually are 4.75 inches in diameter and less than one-twentieth of an inch think.

Use to store software, data, digital photos, movies and music. Some optical discs formats are read only, others are read/write. Optical discs store items by using microscopic pits (indentations) and lands (flat areas)

that are in the middle layer of the disc. Guidelines for the proper care of optical discs:

Optical disk format:1. CD-ROM2. CD-R3. CD-RW4. DVD-ROM


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5. BD-ROM6. HD DVD-ROM7. DVD-R8. DVD+R9. BD-R10. HD DVD-R11. DVD-RW12. DVD+RW13. DVD-RAM14. BD-RE15. HD DVD-RW

CD-ROM:

Stand for compact disc read-only memory. Is a type of optical disc that users can read but not write or erase. The contents for standard CD-ROMs was write by manufactures. A standard CD-ROMs is called a single-session disc because manufactures

write all items on the disc at one time. These CD-ROM normally used to distribute the software. A typical CD-ROM holds from 650 MB to 1 GB of data, instruction and

information. We can read the CD-ROM by using CD-ROM drive or CD-ROM player.

CD-R and CD-RW

CD-R (compact disc-recordable) is a multisession optical disc on which user can write but not erase.

Multisession means you can write on part of the disc at one time and another part at a later time.

CD-RW (compact disc-rewritable) is an erasable multisession disc you can write on multiple times.

To write on a CD-RW disc, we must use CD-RW software and CD-RW drive. The process of writing on an optical disc is called burning. The process of copying audio and video data from a purchased disc and

saving it on digital media is called ripping.


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DVD-ROM, BD-ROM and HD DVD-ROM

DVD-ROM (digital versatile disc-read-only memory or digital video disc-read-only memory) is a high-capacity optical disc on which users can read but not write or erase.

Manufacturers write the contents of DVD-ROMs and distribute them to consumers.

DVD-ROMs store movie, music, huge database and complex software. To read a DVD-ROM, we must have a DVD-ROM drive or DVD player. Most

DVD drivers can read audio CDs, CD-ROMs, CD-Rs and CD-RWs. Drives called DVD/CD-RW, are combination drives that read DVD and CD

media. 2 newer and more expensive DVD format are Blu-ray and HD DVD, both of

them have a higher capacity and better quality than standard DVDs. A Blu-ray (BD) has storage capacities of 100GB with expectations of

exceeding 200 GB in the future. The HD DVD disc (high-density-DVD) has storage capacities up to 60 GB with

future projection of 90 GB capacities

RECORDABLE AND REWRITABLE DVDs DVD-R, DVD+R, BD-R and HD DVD-R allow users to write on the disc once

and read (play) it many times. DVD-RW, DVD+RW and DVD+RAM are three competing rewritable DVD

formats. DB-RE and HD DVD-RW are competing high-capacity rewritable DVD

formats. To write on these discs, we must have compatible driver or recorder.

Tape

One of the storage media used with mainframe.


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Tape is a magnetically coated ribbon of plastic capable of storing large amounts of data and information at a low cost.

Uses for long-term storage and backup. Tape drive reads and writes data and information on a tape. Today’s tape drives use tape cartridges. Tape cartridges is a small, rectangular, plastic

housing for tape.

PC cards and Express cards

A PC card is a thin, credit card sized removable flash memory device that fits into a PC card slot.

An ExpressCard module is a removable device, smaller than a PC card and fits in a ExpressCard slot.

PC card and ExpressCard modules can be used to add memory, storage, communications, multimedia and security capabilities to a computer.

Its commonly used in notebook computers.


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Miniature mobile storage media

Allow mobile users easily to transport digital images, music or documents to and from computers and other devices.

Many desktop, notebook, tablet PCs, digital cameras, portable media players, smart phones and other personal mobile devices have built in ports or slots to hold miniature mobile storage media.

For computers or devices without built in slots, user can insert the media in separate peripherals such as card reader/writers, which typically plugs in a USB port.

3 types of miniature mobile storage are:1. Flash memory cards


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Various flash memory cards:

Media name Storage capacity useCompact flash 64 MB to 16 GB Digital cameras, smart phones, PDAs,

photo printers, portable media players, notebook computers, desktop computers

Secure digital (SD) 64MB to 8 GB Digital cameras, digital video cameras, smart phones, PDAs, photo printers, portable media players.

MicroSD 512 MB to 6 GB Smart phones, portable media players, handheld game consoles, handheld navigation devices.

MiniSD 512 MB to 4 GB Smart phones, portable media players, digital cameras

xD picture card 64 MB to 2 GB Digital cameras, photo printers


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Memory stick 256 MB to 4 GB Digital cameras, digital video cameras, photo printers, smart phones, PDAs, handheld game consoles, notebook

Memory stick PRO Duo 128 MB to 8 GB Digital cameras, smart phones, handheld game consoles

2. USB flash drivers Plugs in at USB port on a computer or mobile device. Storage capacities from 256 MB to 64 GB


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3. Smart cards Stores data on microprocessor embedded in small card Contain a processor and have input, process, output and storage

capabilities. Smart card sis uses to storing medical records, vaccination data and other

health care or identification information, customer purchases, employee attendance, prepaid amount of money

Microfilm and microfiche

Microfilm and microfiche store microscopic images of documents on roll or sheet film. Microfilm is a 100 to 215 foot roll of film and microfiche is a small sheet of film about 6 X

6 inches. Is uses to:

1. Store back issues of newspapers, magezines and genealogy records.2. Store transactions and canceled checks3. Store personal records ( US army)


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Enterprise storage

Use by large business/ enterprise. Enterprise use computer and computer networks to manage and store huge volumes of

data and information about customers, suppliers and employee. In an enterprise, some storage system provide more than 185 TB of storage capacity CD server and DVD server hold hundreds of CDs and DVDs.

Suggested storage devices for various types of computer users:

User Typical storage devicesHome 250 GB hard disk

Online storage CD or DVD drive Card reader/writer USB flash drive

Small office/ home office 500 GB hard disk Online storage CD or DVD drive External hard drive for backup USB flash drive

Mobile 100 GB hard disk Online storage CD or DVD drive Card reader/writer Portable hard disk for backup USB flash drive

Power 1.5 TB hard disk Online storage CD or DVD drive Portable hard disk for backup USB flash drive

Large busines Desktop computer 500 GB hard disk CD or DVD drive


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Smart card reader Tape drive USB flash drive

Server or Mainframe Network storage server 40 TB hard disk system CD-ROM or DVD-ROM server Microfilm or microfiche

Chapter 7: Communications and Networks

Communications

Is a process in which 2 or more computers or devices transfer data, instructions and information.

Some communications involve cables and wires and other are sent wirelessly through the air.

For successful communications we need:


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All types of computers and mobile devices serve as sending and receiving devices in communication system.

Modem is a communication device that uses to connect to communications channel. 2 popular communications channel are: television lines and telephone lines.

Use of computer communications

Variety of computer communications:

Uses of communication purposeInternet o World wide collection of networks that links millions of

business, government agencies, educational institutions and individual.

Web o World wide collection of electronic documents on the internet that users access through a web browser.

e-mail o Transmission of messages and files via a computer network

Instant messaging o Real-time one-on-one communications service on the internet that notifies you when one or more people are online and then allows you to exchange messages, pictures, file, audio and video.


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Chat rooms o Real time type conversation among 2 or more people that takes place on a computer connected to a network that also may allow the exchange of messages, pictures, file, audio and video.

Newsgroups o Online areas in which users have written discussions about a particular subject.

Blogs o Time-stamped articles on a network that reflect the author’s interests, opinions and personality.

Wikis o Collaborative web sites that allow users to create, add to, modify or delete web site content.

RSS o Specification that enables web content to be distributed to subscribers.

VoIP o Conversation that takes place over the internet using a telephone connected to a computer or mobile device or telephone adapter.

FTP o Internet standard that permits users to upload and download files to and from FTP server on the internet.

Web Folders o Location on web server to which user publish documents and other files.

Video conferencing o Real time meeting between 2 or more geographically separated people who use a network to transmit audio and video data.

Fax machine or computer fax/modem

o Transmits and receives documents over telephone lines.

Wireless messaging services o Send and received messages to and from smart phones, cell phones, handheld game consoles and other personal mobile devices

o The 3 techniques use to send and receive messages are:1. Text messaging

o Also call SMS (short message service)


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o Option for sending and receiving messages:- Mobile to mobile- Mobile to e-mail- Web to mobile- Mobile to provider ( example television

program contstant)

2. Wireless instant messaging

Is a real time internet communications service that allows wireless mobile devices to exchanges message with one or more mobile devices or online user.

3. Picture/video messaging

With picture messaging, user can send picture and sounds files as well as short text messages to phone or other personal mobile device or a computer.

With video messaging , user can send short video clips ( about 30 seconds in length) to all pictures messaging services.

Also called as a MMS ( multimedia message service)

Wireless internet access points

Wireless internet access point is to connect the internet wirelessly by using mobile computer, smart phones, handheld game consoles or other devices.

User can access wireless internet access point with built in wireless capacity or the other appropriate wireless network card, PC card, expresscard module or USB network adapter.

2 types of wireless internet access point are:~ hot sport~ mobile wireless networks

A hot sport is a wireless network that provides internet

connections to mobile computer and other devices.

3 hot sport technologies are: Wi-Fi (users in public such as airport,

restaurants, hotels, shopping mall etc) WiMAX (coverage much wider than Wi-

Fi such as an entire city) Bluetooth ( provide location based


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service such as sending coupons or menus)

A mobile wireless network Provides user with high speed internet

connection Have a subscription fee

Cybercafé Is a location that provides personal computer with internet access to its customers.

Some provide free internet access, most charge a per-hour or per minute fee and some of them also are hot sport.

Global positioning systems GPS is a navigation system that consists of one or more earth-based receivers that accept and analyze signals sent by satellites in order to determine the receiver’s geographic location.

A GPS receiver is a handheld, mountable or embedded device that contains an antenna, a radio receiver and a processor and screen to display an individual location on a map.

Many mobile devices such as smart phones have GPS

Collaboration Is a work online with other users connected to a server. 2 method of collaboration are:

1. Collaborative software2. Document management systems.

Collaborative software: Includes tools that enable users to share

documents via online meetings and communication with other connected users.

An online meeting allows users to share documents with other in real time and we call it’s as a WEB CONFERENCE.

Collaborative software often has chat, white board and video/audio conferencing.

Some companies use document management system to make collaboration possible among employees.

Document management system: Provide for storage and management of a

company’s documents such as word processing,


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presentations and spreadsheets. User can access these documents depending on

their needs. Google Docs is a web based document

management system that provides basic services to its subscribers at no cost.

Groupware Is software that helps group of people work together on projects and share information over a network.

Is a component of a broad concept called workgroup computing which includes network hardware and software that enables group members to communicate, manage project, schedule meeting and make group decisions.

Most group ware provide personal information manager (PIM) function such as an electronic appointment calendar, an address book and a notepad.

Voice mail Which functions much like an answering machine, allows someone to leave a voice message for one or more people.

Some voice mail system can send digital voice mail files to an email address and others can convert a voice mail message to a text message for display on a computer or mobile devices.

Web services Describe standardized software that enables programmers to create applications that communicate with other remote computers over the internet or over an internal business network.

Network-types or classifications, architecture, topology

Introduction:

Network is a collection of computers and devices connected together via communication devices and transmission media.

Network is used to facilitate communications, share hardware, share data and information, share software and transfer funds.


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Network can be internal to an organization or span the word by connecting to the internet.

Value added network(VAN) is a third party business that provides networking services for a fee.

Types or classification of network:

3 types of networks:1. LAN (Local area network)2. WAN (wide area network)3. MAN (metropolitan area network)

LAN Is a network that connects computer and devices in a limited geographical area

such as a home, school computer laboratory, office building. Each computer and device on the network are called a node, often shares

resources such as printer, large hard disk and program. The nodes are connected via cables. A wireless LAN (WLAN) is a LAN that uses no physical wires.

WAN

Is a network that covers a large geographic area (such as a city, country or the world) using a communications channel that combines many types of media such as telephone lines, cables and radio waves.

A WAN can be one large network or can consist of 2 or more LANs connected together.

The internet is the worlds largest WAN.


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MAN

Is a high-speed network that connect local area network in a metropolitan area such as a city or town and handles the bulk of communications activity across the region.

A MAN typically includes one or more LANs, but covers a smaller geographic area then a WAN.

A MAN usually is managed by a consortium of users or by a single network provider that sells the service to the users.

Example: telephone companies, cable television operators.

Network architectures:


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Is a design of computer, devices and media in a network. 2 categories of network architectures are:

o Client/ Server One or more computer act as a server; the other computer on the

network request services from the server. A server control access to the hardware, software and other resources on

the network and provides a centralized storage area for programs, data and information.

Some servers, called dedicated servers, perform a specific task and can be places with other dedicated servers to perform multiple tasks.

The clients are other computer and mobile devices on the network that rely on the server for its resources.

A client/ server network typically provides a efficient means to connect 10 or more computer and require a person to serve as a network administrator ( because of the large size of the network)


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o Peer –To-Peer Called P2P An internet network

on which users access each others hard disk and exchange files directly.

These type of P2P network sometimes called as a file sharing network because users with compatible software and an internet connation

copy files from someone else’s hard disk. And when users log off, other no longer have access to their hard disks.

Example: BitTorrent, Gnutella, Kaza and LimWire.

Network topolgies:

Refers to the layout of the computers and devices in a communication network.

3 common network topologies uses are:

o Bus


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Consists of a single central cable to which all computers and other devices connect.

The bus is the physical cable that connects the computers and other devices.

The bus in a bus network transmit data, instruction and information in both direction.

bus networks are popular on LANs because they are inexpensive and easy to install.

The advantage: 1. The computers and other devices can be attached and detected at

any point on the bus without disturbing the rest of the network.2. Failure of one device usually does not affect the rest of the bust

network.

o Ring A cable forms a closed loop (ring) with all computers and devices

arranged along the ring. Data transmitted on a ring network travels from device to device around

the entire ring in one direction. When a computer or devices sends data, the data travels to each

computer on the ring until it reaches its destination. If a computer or devices on a ring network fails, all devices before the

failed are unaffected but those after the failed device cannot function. Span a larger distance than a bus network, but it is more difficult to

install.


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Used in LANs and also in WANs.

o Star All the computers and devices (nodes) on the network connect to a

central device, thus forming a star. 2 types of devices that provide a common central connection point for

nodes on the network are hub and a switch. All data that transfer from one node to another passes through the

hub /switch. Easy to install and maintain. Nodes can be added and removed from the network with little or no

disruption to the network.


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On star network, if one node fails, only that node is affected but if the hub/switch fails, the entire network is inoperable until the device is repaired.

Communications software

Is a program that use to:1. Help users establish a connection to another computer or network2. Manage the transmission of data, instruction and information.3. Provide an interface for user to communicate with one another.

Example: e-mail, FTP, web browser, newsgroup, chat rooms, instant messaging, video conferencing and VoIP.


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Communications over the telephone network

The public switched telephone network (PSTN) is the world wide telephone system that handles voice-oriented telephone calls.

Nearly the entire telephone network today uses digital technology, with the exception of the final link from the local telephone company to a home (which is analog)

The telephone network is an integral park of computer communications. Data, instructions and information are transmitted over the telephone network using :

dial-up lines and Dedicated lines.

Dial-up lines:

Is a temporary connection that uses one or more analog telephone lines for communications.

Using a dial-up line to transmit data is similar to using the telephone to make a call. A modem at the sending end dials the telephone number of a modem at the receiving

end. When the modem at the receiving end answers the call, a communication is established and data can be transmitted,

Cost is same with a regular telephone call.

Dedicated lines:

Is a type of always on connection that is established between 2 communications devices.

Quality and consistency much better because dedicated lines provide a constant connection.

Dedicated lines can be either analog or digital. 5 types of dedicated lines are:

1. ISDN lines Stand for Integrated Services Digital Network Is a set of standard for digital transmission of data over standard copper

telephone lines. Used for home and small business.


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Provides faster transfer rates than dial-up ISDN requires that both ends of the connection have an ISDN modem.

2. DSL Stand for Digital Subscriber Line. Is a popular digital line alternative for the small business or home user. To connect to DSL, customer must have a special network card and a DSL

modem. ADSL (asymmetric digital subscriber line) is a type of DSL that support

faster rates when receiving data than when sending data.

3. FTTP Stand for Fiber to the Premises. Uses fiber-optic cable to provide extremely high speed internet access to

a user’s physical permanent location. 2 specific types of FTTP are:

FTTH (fiber to the home) FTTB (fiber to the building)

With FTTP service, an optical terminal at your premises receives the signals and transfers them to a router connected to your computer.

4. T-carrier lines Types of long distance digital telephone lines that carry multiple signals

over a single communications line. Provide very fast data transfer rates. Very expensive. The popular T-carrier line is T1 line. T1 is uses to connect to the internet backbone.

5. ATM Stand for asynchronous transfer mode. Is a service that carries voice, data, video and multimedia at extremely

high speeds. Telephone networks, the internet and other networks with large

amounts of traffic use ATM


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Below is a list of the speeds of various lines that can be used to connect to the internet:

Communication devices

A communication device is any type of hardware capable of transmitting data, instructions and information between a sending device and a receiving device.

types of communication device are:1. Dial up modem2. ISDN and DSL modems3. Cable modems


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4. Wireless modems5. Network cards6. Wireless access points7. routers

Communication channels and media –physical and wireless

Communication channels and media:

is the transmission media on which data, instruction or information travel in a communication system.

The amount of data, instruction and information that travel over a communication channel called bandwidth.

The higher the bandwidth, the more the channel transmits. A communication channel consists of one or more transmission media. Transmission media consists of materials or substances capable of carrying one or more

signals. 2 types of transmission media are: physical and wireless. An example of sending a request over the internet using a communication channel:


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Physical transmission media:

Used in communications include twisted-pair cable, coaxial cable and fiber optic cable. These cable are used within or underground between building. Physical transmission media normally use in Ethernet and token ring LANs.

Twisted pair cable:

Used for network cabling and telephone system. Its consists of one or more twisted pair wires bundled together. Each twisted pair

wire consists of 2 separate insulated copper wires that are twisted together. The wires are twisted together to reduce noise. Noise is an electrical disturbance

that can degrade communications.


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Coaxial cable:

Referred to as coax (pronounced KO –ax). Consists of a single copper wire surrounded by at least 3 layers:

1. An insulating material2. A woven or braided metal3. A plastic outer coating


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Its use in cable television (CATV) network wiring because it can be cabled over longer distances than twisted pair cable.

Fiber optic cable:

Consists of dozens or hundreds of thin strands of glass or plastic that use light to transmit signals.

Each strand, called an optical fiber, is as thin as a human hair. Inside the fiber optic cable, an insulating glass cladding and a protective coating

surround each optical fiber.

The advantages of using fiber optic are:1. Capability of carrying significantly more signals than wire cables.2. Faster data transmission3. Less susceptible to noise from other device such as a copy machine.4. Better security for signals during transmission because they are less

susceptible to noise.5. Smaller size.

Disadvantage of using fiber optic cable:1. Expensive2. Difficult to install and modify


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Wireless transmission media:

It more convenient than installing cable. Types of wireless transmission media are:

o Infrared Transmission medium that sends signals using infrared light waves. Mobile computers and device such as a mouse, printer and smart phone

have an IrDA port that enables the transfer of data from one device to another using infrared light waves.

o Broadcast radio Is a wireless transmission that distributes radio signals through the air

over long distances such as between cities, regions and countries and short distances such as within an office or home.

Example of device use broadcast radio signals are: Bluetooth, UWB, Wi-Fi and WiMAX.

o Cellular radio Is a form of broadcast. Is used for mobile communication, specifically wireless modems and cell

phones. A cell phone is a telephone device that uses high-frequency radio waves

to transmit voice and digital data message. Some mobile users connect their notebook or other mobile computer to

a cell phone to access the web, send and receive email, enter a chat room.

o Microwaves Are radio waves that provide a high speed signal transmission. Microwave transmission are called foxed wireless, involves sending

signals from one microwave station to another. Microwaves can transmit data are rates up to 4500 times faster than a

dial-up modem. A microwaves station is an earth based reflection dish that contains the

antenna, transceivers, and other equipment necessary for microwave communication.

Is used in environments where installing physical transmission media is difficult or impossible and where line of sigh transmission is available.


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o Communications satellites Is a space that receives microwave signals from an earth-based station,

amplifies the signals and broadcasts the signals back over a wide area to any number of earth based station.

Is use in air navigation, television and radio broadcasts, weather forecasting, video conferencing, paging, global positioning system and internet connection.

Chapter 8: Database Management

Database, data and information

Database is a collection of data organized in a manner that allow access, retrieval and use of that data.

Data is a collection of unprocessed items, which can include text, numbers, images, audio and video.

Information is processed data, that is, it is organized, meaningful and useful.


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Computer process data in a database into information. Example how a data process into information:

With database software, often called a database management system (DBMS), users create a computerized database; add, change and delete data in the database; sort and retrieve data from database; create forms and reports from the data in the database.

Data integrity: Most companies realize that data is one of their more valuable assets – because

data is used to generate information. To ensure that data is accessible on demand, a company must manage and

protect its data just as it would any other resource, thus it is vital that the data has integrity and is kept secure.


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Data integrity identifies the quality of the data. When a database contains an error, it loses integrity.

Garbage in, garbage out (GIGO) is a computing phrase that points out the accuracy of a computer’s output depends on the accuracy of the input.

If we enter incorrect data into a computer (garbage in), the computer will produce incorrect information (garbage out).

Qualities of valuable information:

The information that data generates also is an important asset. People make decisions daily using all types of information such as receipts, bank

statement, pensions plan summaries, stock analyses and credit reports To assist with sound decision making, the information must have value. For it to

be valuable, information should be accurate, verifiable, timely, organized, accessible, useful and cost effective

o Accurate - information is error free.o Verifiable - information can be proven as correct or incorrect.


Garbage out

Garbage in

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Data integrity

is lost


o Timely - information has an age suited to its use.o Organized - information is arranged to suit the needs and requirements

of the decision maker.o Accessible – information is available when the decision maker needs it.o Useful – information has meaning to the person who receives it.o Cost effective – information should give more value than its cost to

produce.

Hierarchy of data

Data is organized in layers. In the computer profession, data is classified in a hierarchy. Each higher level of data

consists of one or more items from the lower level. As shown in figure below, a database contains files, a file contains records, a record

contains fields and a field is made up of one or more characters.

Characters: A bit is the smallest unit of data the computer can process. Eight bits grouped together in a unit comprise a byte.

In the ASCII and EBCDIC coding schemes, each byte represents a single character, which can be a number, letter, punctuation mark or other symbol.


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Fields: A field is a combination of one or more related characters or bytes and is the

smallest unit of data a user accesses. A field name uniquely identifies each field. When searching for data in a database, you often specify the field name. For

example : field name for the data in the membership file shown in figure below are membership code, membership name and annual fee.

A database uses a variety of characteristics such as field size and data type to define each field.

The field size defines the maximum number of characters a field can contain. The data type specifies the kind of data a field can contain and how the field is

used. The example of data type are:


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Yes/NoYes/No

only the values Yes or No (or True or

False)

HyperlinkHyperlink

Web address that links to document or Web page

ObjectObject

photograph, audio, video, or document created in other application such as word

processing or spreadsheet

CurrencyCurrency

dollar and cent amounts or numbers containing decimal

values

DateDate

month, day, year, and sometimes time

MemoMemo

lengthy text entries

TextText

(also called alphanumeric)—letters,

numbers, or special characters

NumericNumeric

numbers

only

AutoNumberAutoNumber

unique number automatically assigned to each new record


Records: A record is a group of related field . For example, a member record includes a set of fields about one member.


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key field

records fields

22 Fifth Avenue

P.O. Box 45

15 Duluth Street

33099 Clark Street

1029 Wolf Avenue

Address

Auburn

Clanton

Prattville

Montgomery

Montgomery

City

ALRuizAdelbert3928

ALElena4872

ALDrakeLouella3876

ALMurrayShannon2928

ALBrewerMilton2295

StateLast NameFirst NameMember ID

Gupta


A key field or primary key, is a field that uniquely identifies each record in a file. The data is unique to a specific record.

Files: A data file is a collection of related records stored on a storage medium such as a

hard disk, CD or DVD.

Maintaining data

File maintenance refers to the procedures that keep data current. File maintenance procedures include adding records to, changing records in and

deleting records from a file.

Adding records:


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Uses to add new records to a file when they obtain new data. Example:

Changing records: Users change a record in a file for 2 reasons:

o To correct inaccurate datao To update old data with new data

Example:


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Deleting records: When a record no longer is needed, a user deletes it from a file. DBMS use a variety of techniques to manage deleted records. Sometimes, the DBMS

remove the record from a file immediately, which means the deleted record cannot be restored. Other times, the record is flagged or marked so the DBMS will not process it again.

From time to time, users should run a utility program that removes the flagged records and reorganizes current records. For example, the discount warehouse may remove from disk any accounts that have been canceled for more than one year.

Example:

Validating data: Validation is the process of comparing data with a set of rules or values to find out if

the data is correct. Many programs a validity check that analyzes entered data to help ensure that it is

correct. Its Reduce data entry errors and enhance data integrity before program writes

data on disk Example:


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Consistency Check

tests for logical relationship between two or more fields

Consistency Check

tests for logical relationship between two or more fields

Range Check determines whether number is within specified range

Range Check determines whether number is within specified range

Completeness Check

verifies that a required field contains data

Completeness Check

verifies that a required field contains data

Check Digit

number(s) or character(s) appended to or inserted into a primary key value to confirm accuracy of primary key value

Check Digit

number(s) or character(s) appended to or inserted into a primary key value to confirm accuracy of primary key value

Alphabetic/

Numeric Check ensures correct type of data entered

Alphabetic/

Numeric Check ensures correct type of data entered


Types of validity checks:


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File processing Vs Database management system

Almost all application programs use the file processing approach, the database approach or a combination of both approaches to store and manage data.

File processing system/ approach:1. In typical file processing system, each department or area within an organization

has its own set of files.2. The records in one file may not relate to the records in any other file.3. Companies have file processing systems for many years. A lot of these systems,

however have 2 major weaknesses: Data redundancy – each department or area in a company has its own

files in a file processing system. Thus the same field is stored in multiple files.

Isolated data – often it is difficult to access data stored in separate files in different departments. Sharing data from multiple, separate files are a complicated procedure and usually require the experience of a computer programmer.

The database approach:1. When a company uses the database approach, many programs and users share

the data in the database.2. The database does secure its data, however only the authorized users can access

certain data items.3. While a user is working with the database, the DBMS resides in the memory of

the computer.4. The advantages of database approach:

Reduced data redundancy – most data items are stored in only one file, which greatly reduces duplicate data.

Improve data Integrity – when users modify data in the database, they make changes to one file instead of multiple files. Thus the database approach increases the data’s integrity by reducing the possibility of introducing inconsistencies.

Share data - the data in a database environment belongs to and is shared, usually over a network by the entire organization. Companies that use


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databases typically have security setting to define who can access, add, change and delete the data in a database.

Easier Access – the database approach allows nontechnical users to access and maintain data, providing they have the necessary privileges.

Reduced development time – it often is easier and faster to develop programs that use the database approach.

5. The disadvantages of database approach: More complex Its require more memory, storage and processing power.

6. Data in a database can be more vulnerable than data in file processing systems. 7. A database can store a lot of data in a single file. Many users and programs share

and depend on this data. If the database is not operating properly or is damaged or destroyed, users may not be able to perform their job.


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Chapter 9: Security, Ethics and Privacy

Computer security risk

A computer security risk is any event or action that could cause a loss of or damage to computer hardware, software, data, information or processing capability.

An intentional breach of computer security often involve a deliberately act thet is against the law.

Any illegal act involving a computer generally is referred to as a computer crime. The term cybercrime refer to online or internet based illegal acts. Perpetrators of cybercrime and other intrusions fall into 7 basic categories:

1. Hacker – although originally a complimentary word for a computer enthusiast, now has a derogatory meaning and refers to someone who accesses a computer or network illegally. Some hacker claim the intent of their security breaches is to improve security.

2. Cracker – also is someone who access a computer or network illegally but has the intent of destroying data, stealing information, or other malicious action. Both cracker and hackers have advanced computer and network skills.

3. Script kiddie – has the same intent as a cracker but does not have the technical skills and knowledge. Script kiddies often are teenagers that use prewritten hacking and cracking programs to break into computers.

4. Corporate spy – have excellent computer and network skills and are hired to break into a specific computer and steal its proprietary data and information. Unscrupulous companies hire corporate spies, a practice known as corporate espionage, to gain a competitive advantage.

5. Unethical employee – break into their employers’ computer for a variety of reasons. Some simply want to exploit a security weakness. Others seek financial gains from selling confidential information.


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6. Cyberextortionist – is someone who uses e-mail as a vehicle for extortion. These perpetrators send a company a threatening e-mail message indicating they will expose confidential information, exploit a security flaw, or launch an attack that will compromise the company’s network.

7. Cyberterrorist – is someone who uses the internet or network to destroy or damage computers for political reasons. The extensive damage might destroy the nation’s air traffic control system, electricity-generating companies or telecommunications infrastructure. Cyberterrorism usually requires a team of highly skilled individuals, millions of dollars and several years of plenning.

Internet and network attacks

Information transmitted over network has a higher degree of security risk than information kept on a company’s premises.

In a business, network usually take measures to protect a network from security risks. Internet and network attacks that jeopardize security include computer viruses, worms

and Trojan horses; botnets, denial of service attack; back doors and spoofing.1. Computer virus – is a potentially damaging computer programs that affects, or

infects , a computer negatively by altering the way the computer works without the user’s knowledge or permission. One the virus infects the computer, it can


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spread throughout and may damage files and system software, including the operating system.

2. Worm – is a program that copies itself repeatedly, foe example in memory or on a network, using up resources and possibly shutting down the computer or network.

3. Trojan horse – (named after the Greek myth) is a program that hides within or looks like a legitimate program. A certain condition or action usually triggers the Trojan horse. Unlike a virus or worm, a Trojan horse does not replicate itself to other computers.

4. Botnets – is a group of compromised computer connected to a network such as the internet that are used as part of a network that attacks other networks, usually for nefarious purpose. A compromised computer, known as a zombie, is one whose owner is unaware the computer is being controlled remotely by an outsider. Cybercriminals use botnets to send spam via e-mail, spread viruses and other malware or commit a denial of service attack.

5. Denial of service attacks – or Dos attack is an assault whose purpose is to disrupt computer access to an internet service such as the web e-mail. Perpetrators carry out a Dos attack in a variety of ways. For example, they may use an unsuspecting computer to send an influx of confusing data messages or useless traffic to a computer network. The victim computer network eventually jams, blocking legitimate visitors from accessing the network.

6. Back door – is a program or set of instruction in a program that allow users to bypass security control when accessing a program, computer or network. Once perpetrators gain access to unsecured computers, they often install a back door or modify an existing program to include a back door, which allows them to continue to access the computer remotely without the user’s knowledge.

7. Spoofing – is a technique use to make their network or internet transmission appear legitimate to a victim computer or network. E-mail spoofing occurs when the sender’s address or other components of the e-mail header are altered so that it appears the e-mail originated from a different sender. E-mail spoofing commonly is used for virus hoaxes, spam and phishing scams. IP spoofing occurs


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when an intruder computer fools a network into believing its IP address is associated with a trusted source.

Every unprotected computer is susceptible to the first type of computer security risk. Computer viruses, worms and Trojan horses are classified as malware ( short for

malicious software) which are program that act without a user’s knowledge and deliberately alter the computer’s operation.

Unscrupulous programmers write malware and then test it to ensure it can deliver its payload.

The payload is the destructive event or prank the program is intended to deliver. A computer infected by a virus, worm or Trojan horse often has one or more of the

following symptoms:1. Screen display unusual message or image.2. Available memory is less than expected.3. Files become corrupted4. Unknown programs or file mysteriously appear.5. Music or unusual sound plays randomly.6. Existing programs and files disappear7. Programs or file do not work properly8. System properties change9. Operating system runs much slower than usual.

Computer viruses, worms and Trojan horses deliver their payload on a computer in 4 basic way:

1. Opens an infected file2. Run an infected program3. Boot the computer with infected removable media inserted in a drive or plugged

in a port.4. Connect an unprotected computer to a network

A common way computer become infected with viruses, worms and Trojan horses is through users opening infected e-mail attachment.

Safeguards against computer viruses, worm and Trojan horses by using:

Do not start a computer with removable media such as CDs. DVDs and USB flash drives.


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Never open an e-mail attachment unless you are expecting the attachment and it is from a trusted source.

Set the macro security in programs so you can enable or disable macros Install an antivirus program on all of your computers If the antivirus program flags an e-mail attachment as infected, delete

the attachment Check all downloaded programs for viruses, worms, or Trojan horses Install a personal firewall program

Safeguards against botnets, DoS attacks, back door and spoofing by using: Firewalls

o Security system consisting of hardware and/or software that prevents unauthorized network access

Personal firewallo Program that protects personal computer and its data from unauthorized

intrusions


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o Monitors transmissions to and from computero Informs you of attempted intrusion

Unauthorized access and use

Unauthorized access Is the use of a company or network without permission Unauthorized use is the use of a computer or its data for unapproved or possibly illegal

activities. Safeguards against unauthorized access and use by using:

1. Firewalls Security system consisting of hardware and/or software that prevents

unauthorized network access Program that protects personal computer and its data from

unauthorized intrusions Monitors transmissions to and from computer Informs you of attempted intrusion

2.2.2.2.2.2.2.2.2.2.2.2.2.2.

Intrusion Detection software analyzes network traffic, assesses system vulnerabilities, and identifies

intrusions and suspicious behavior

Identifying and authenticating users:


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1. Username and password Unique combination of characters that identifies user Password is private combination of characters associated

with the user name that allows access to certain computer

2. Possessed objects Item that you must carry to gain access to computer or facility Often used with numeric password called personal identification

number (PIN)

3. Biometric devices Authenticates person’s identity using personal characteristic

Fingerprint, hand geometry, voice, signature, and iris

Hardware, software, information theft and vandalism

Hardware theft and vandalism:


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1. Hardware theft is the act of stealing computer equipment. Cables sometimes used to lock equipment Some notebook computers use passwords, possessed objects, and

biometrics as security methods For PDAs and smart phones, you can password-protect the device

2. Hardware vandalism is the act of defacing or destroying computer equipment.3. Safeguards against hardware theft and vandalism by using:

Real time location system (RTLS)

Software theft:1. Occurs when someone steals software media, intentionally erase programs or

illegally copies a program.2. Software privacy is the unauthorized and illegal duplication or copyrighted

software.3. Safeguards against software theft by using:

Back up the file and disks Product activation

allows user to input product identification number online or by phone and receive unique installation identification number

License agreement Right to use software


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Single-user license agreement allows user to install software on one computer, make backup copy, and sell software after removing from computer

Information theft:1. Occurs when someone steals personal or confidential information2. Safeguards against information theft by using:

Encryption Process of converting plaintext (readable data) into ciphertext

(unreadable characters) Encryption key (formula) often uses more than one method To read the data, the recipient must decrypt, or decipher, the

data


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Pretty good privacy (PGP) is popular e-mail encryption program

Digital signature is encrypted code attached to e-mail message to verify identity

of sender

Secure site is Web site that uses encryption to secure data

Digital certificate is notice that guarantees Web site is legitimate

Certificate authority Authorized person or company that issues and verifies digital

certificates Users apply for digital certificate from CA

System failure

System failure is another type of computer security risk. A system failure is the prolonged malfunction of a computer. System failure can cause loss of hardware, software, data or information A variety of causes can lead to system failure include natural disasters such as fire,

floods or hurricanes; random events such as electrical power problem and even errors in computer programs.

One of the more common accuses of system failure is an electrical power variation. Electrical power variations can cause loss of data and loss of equipment. If the computer equipment is networked, a single power disturbance can damage multiple systems.

Safeguards against system failure:1. To protect electrical power variations, use a surge protector.2. A surge protector uses special electrical components to provide a stable current

flow to the computer and other electronic equipment. 3. Sometimes resembling a power strip, the computer and other devices plug in the

surge protector, which plugs in the power source.4. If your computer connects to a network or the internet, also be sure to have

protection for your modem, telephone lines, DSL lines, internet cable lines and network lines.


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5. Many surge protectors include plug-ins for telephone lines and other cables.6. For additional electrical protection, some application connects an uninterruptible

power supply to the computer.7. An uninterruptible power supply (UPS) is a device that contains surge protection

circuits and one or more batteries that can provide power during a loss of power.8. A UPS connects between your computer and a power source.

Backing up

A backup is a duplicate of a file, program or disk that can be used if the original is lost, damaged or destroyed.

We can use any media to store backups. A good choice for a home user might be CD-RW or DVD + RWs.

Backup copies should keep in a fireproof and heatproof safe or vault or offsite. Most backup programs for home user provide for a full backup and a selective backup. A

full backup copies all of the files in the computer. With a selective backup, users choose which folders and files to include in a backup.

Some users implement a 3 generation backup policy to preserve 3 copies of important files. The grandparent is the oldest copy of the file. The parent is the second oldest copy of the file. The child is the most recent copy of file.

Most operating systems include a backup program. Backup devices, such as tape and removable disk drive, also include backup programs.

Some companies choose to use an online backup service to handle their backup needs. An online backup service is a web site that automatically backs up files to its online location. These sites usually charge a monthly or annual fee. If the system crashes, the online backup service typically sends the company one or more CD/DVDs that contains all it’s backed up data.

Wireless security

The safeguards that improve the security of wireless network include reconfiguring the wireless access point and ensuring equipment uses one or more wireless security such as Wi-Fi protected access and 802.11i

A wireless point (WAP) should be configured so that it does not broadcast a network name. The WAP also can be programmed so that only certain devices can access it.


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Wi-Fi protected access (WPA) is a security standard that improves on older security standards by authenticating network users and providing more advanced encryption techniques.

An 802.11i network, the most recent network security standard, conforms to the government’s security standards and uses more sophisticated encryption techniques than WPA.

Ethics and society

Computer ethics are the moral guidelines that govern the use of computers and information systems.

5 frequently discussed area of computer ethic are unauthorized use of computer and network, software theft, information accuracy, intellectual property right and information privacy.

Information accuracy:1. Information accuracy today is a concern because many users access information

maintained by other people or companies such as on the internet (web page/ web site).

2. Users should evaluate the value of a web page before relying on its content.3. Be ware that the company providing access to the information may not be the

creator of the information.4. In addition to concerns about the accuracy of computer input, some individuals

and organizations raise questions about the ethic of using computer to alter output, primarily graphical output such as retouched photos.

5. Using graphics equipment and software, users easily can digitize photos and then add, change or remove images.

Intellectual property rights:1. Intellectual property (IP) refers to unique original works such as ideas,

inventions, art, writing, processes, company and product names and logos.2. Intellectual property rights are the rights to which creators are entitled for their

work.3. A copyright gives authors and arties exclusive rights to duplicate, publish and sell

their materials. A copyright protects any tangible from of expression.4. Issues of the copyright low led to the development of digital rights management

(DRM), a strategy designed to prevent illegal distribution of movies, music and other digital content.


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Information privacy

Information privacy refers to the right of individuals and companies to deny or restrict the collection and use of information about them.

In the past, information privacy was easier to maintain because information was kept in separate locations. Each retail store had its own credit files.

Today, huge database store this data online. Much of the data is personal and confidential and should be accessible only to authorized users

The figure below show you how to make your personal data private:


Fill in only the necessary information

on rebate, warranty, and

registration forms

Avoid shopping club

and buyers cards

Install a cookie manager

to filter cookies

Inform merchants that you

do not want them to distribute

your personal informationLimit the amount of information

you provide to Web sites; fill

in only required information

Clear your history file when

you are finished browsingSet up a free e-mail account;

use this e-mail address for

merchant forms

Turn off file and print sharing

on your Internet connection

Install a personal firewall

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Electronic profile:1. Data collected when you fill out form on Web2. Merchants sell your electronic profile3. Often you can specify whether you want personal information distributed

Cookies:1. E-commerce and other web application often rely on cookies to identify users.2. A cookie is a small text file that a web server stores on your computer.3. Cookie files typically contain data about you, such as your username or viewing

preferences.4. Many commercial web sites send a cookie to your browser and then your

computer hard disk stores the cookie. The next time you visit the web site; your browser retrieves the cookie from your hard disk and sends the data in the cookie to the web site. Figure below show how web site work with cookies:


Sign up for e-mail

filtering through your

Internet service provider or

use an antispam program,

such as BrightmailDo not reply to spam

for any reasonSurf the Web anonymously

with a program such as

Freedom Web Secure or

through an anonymous

Web site such as

Anonymizer.com

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5. Web sites use cookies for: To track user prefers. To store users password. Keep track of items in a user shopping cart. To track how regularly users visit a site and the web pages they visit while

at the site. To target advertisements.

Spyware and adware:1. Spyware is program placed on computer without user’s knowledge that

secretly collects information about the user.2. Spyware can enter a computer as a virus or as a result of a user installing a new

program.3. The spyware program communicates information is collects to some outside

source while you are online.


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4. Adware is a program that displays online advertisements in a banner or pop-up window on web pages, e-mail messages or other internet services.

5. To remove spyware and adware, you can obtain a spyware and adware remover that can detect and delete spyware and adware.

Phishing:1. Is a scam in which a perpetrator sends an official looking e-mail message that

attempts to obtain your personal and financial information.2. Some phishing e-mail messages ask you to reply with your information; other

directs you to a phony web site or pop-up window that looks like a web site that collects the information.

3. If you receive an e-mail that looks legitimate and requests you update credit card numbers, social security, bank account numbers, password or other private information, the FTC recommends you visit the web site directly to determine if the request is valid. Never click a link in an e-mail message; instead retype the web address in your browser.

4. A phishing filter: is a program that warns or blocks you from potentially fraudulent or suspicious web site.

5. Pharming: is a scam, similar to phishing, where a perpetrator attempts to obtain your personal and financial information, except they do so via spoofing. That is, when you type a web address in the web browser, you are redirected to a phony web site that looks legitimate. The phony web site requests you enter confidential information.

Spam:1. Spam is unsolicited e-mail message sent to many recipients2. How to control a spam by using e-mail filtering and anti spam program.


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Privacy laws:1. The concern about privacy has led to the enactment of federal and state laws

regarding the storage and disclosure of personal data.2. Common points in some of these laws include the following:

Information collected and stored about individuals should be limited to what is necessary to carry out the function of the business or government agency collecting the data.

Once collected, provisions should be made to restrict access to the data to those employees within the organization who need access to it to perform their job duties.

Personal information should be released outside the organization collecting the data only when the person has agreed to its disclosure.

When information is collected about an individual, the individual should know that the data is being collected and have the opportunity to determine the accuracy of the data.

3. Table below shown a summary of the major US government laws concerning privacy:


Collects spam in

central location

that you can

view any time

Service that

blocks e-mail

messages from

designated

sources

E-mail filteringE-mail filtering

Sometimes

removes valid

e-mail messages

Attempts to

remove spam

Anti-spam programAnti-spam program

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Social engineering:1. Is defined as gaining unauthorized access or obtaining confidential information

by taking advantage of the trusting human nature of some victims and the naivety of others.

2. Some social engineers trick their victims into revealing confidential information such as user names and password on the telephone, in person or on the internet.

3. Techniques they use include pretending to be an administrator or other authoritative figure, feigning an emergency situation or impersonating an acquaintance.

4. Social engineers also obtain information from users who do not destroy or conceal information property. These perpetrators sift through company dumpsters, watch or film people dialing telephone numbers or using ATMs and snoop around computer looking for openly displayed confidential information.

Employee monitoring:1. Involves the use of computer to observe, record and review an employee’s use

of a computer, including communications such as e-mail messages, keyboard activity and web sites visited.

2. Many programs exits that easily allow employers to monitor employees, it is legal for employers to use these programs.

3. A frequently debated issue is whether an employer has the right to read employee e-mail messages.

4. Actual policies vary widely. Some companies declare that they will review e-mail messages regularly.

Content filtering:1. Is the process of restricting access to certain material on the web.2. Content filtering opponents argue that the burning any materials violates

constitutional guarantees of free speech and personal rights.3. Many business use content filtering to limit employees’ web access.4. Web filtering software is a program that restricts access to specified web sites.

Computer forensics:1. Also called digital forensics or network forensics or cyber forensics.2. Is the discovery, collection and analysis of evidence found on computer and

network.


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3. Forensics analysis involves the examination of computer media, programs, data and log files on computer, server, and network.

4. Computer forensics use in: Law enforcement Criminal prosecutors Military intelligence Insurance agencies Information security departments in private sector.

5. Computer forensics analyst must have knowledge about law, technical experience with hardware, software, superior communication skills, familiarity with corporate structure and policies, a willingness to lean and update skills and a knack for problem solving.

Chapter 10: Information system development

The system development cycle

Introduction:

A system is a set of components that interact to achieve a common goal. Business many types of systems such as billing system (send invoice and receive

payment from customer), payroll system (receive paychecks), manufacturing system ( customer order), inventory system.

Very often these system also information system. An information system (IS) is a collection of hardware, software, data, people and

procedures that work together to produce quality information. As a computer user in a business, you someday may participate in the modification of an

existing system or the development of a new system. Thus, it is important that you understand the system development process.

The system development cycle is a set of activities used to build an information system.


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System development cycle:

System development cycles often organize activities by grouping them into larger categories called phase.

5 phase of system development cycle are:1. Planning2. Analysis3. Design4. Implementation5. Operation, support and security.

Figure below shown the activities for each phase.


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System development should follow 2 guidelines: arrange activities into phase, involve the users and develop standards.

1. The system development cycle should group activities into phase. Many system development cycles contain the 5 major phase.

2. User must be involved throughout the entire system development cycle. Users include anyone for whom the system is being built. Customers, employees, students, data entry clerks, accountants, sales managers and owners all are examples of users. Users are more apt to accept a new system if they contribute to its design.

3. The system development cycle should have standards clearly defined. Standards are sets of rules and procedures a company expects employees to accept and follow. Having standards helps people working on the same project produce consistent results.

Who participates in the system development cycle?

System development should involves representatives from each department in which the proposed system will be used. This includes both nontechnical users and IT professionals.

During the system development cycle, the system analyst meets and works with a variety of people.


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A system analyst is responsible for designing and developing an information system.

Chapter 11: Enterprise computing

What is enterprise computing

Introduction:


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Enterprise is refer to large multinational corporations, universities, hospitals, research laboratories and government organizations.

Enterprise computing involves the use of computers in networks that encompass a variety of different operating systems, protocols and network architectures.

A typical enterprise consists of corporate headquarters, remote offices, international office and hundreds of individual operating entities, call functional units.

The types of functional units within a typical manufacturing enterprise are accounting and finance, human resources, engineering, manufacturing, marketing, sales, distribution, customer service and information technology.

Each type of functional unit has specialized requirements for its information system. Enterprise manages large amounts of information over an extensive geographical area

and disparate groups of people

Organization structure of an enterprise:

Most traditional enterprise are organized in a hierarchical as shown below.


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Level of users in the enterprise


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In an enterprise, users of information typically fall into 4 categories: Executive Management, Middle Management, operational management and nonmanagement employee.

The types of information that users require depend on their employee level in organization.


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NONMANAGEMENT EMPLOYEES

(on the job decisions)

OPERATIONAL MANAGEMENT

(operational decisions)

MIDDLE MANAGEMENT

(tactical decisions)

EXECUTIVE MANAGEMENT

(Strategic decisions)

Sample job title:Chief executive officerChief financial officerPresidentVice presidentChief information officerChief operating officer

Human resources managerPublic relations managerPurchasing manager

Office managerShop floor foremansupervisor

AccountantEngineerSecretaryOrder entry cleck


Enterprise information

How managers use information:

Manager are responsible for coordinating and controlling on organizations resources. Manager coordinate these resources by performing 4 activities:


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Manager utilize a variety of tools and techniques to focus on information that is important to the decision making process.

The tools and techniques use are : o Business intelligence (BI)

Includes several types of applications and technologies for acquiring, storing, analyzing and providing access to information to help users make more sound business decisions.

BI application includes decision support systems, query and reporting, online analytical processing (OLAP), statistical analysis and data mining.

o Business process management (BPM) Includes a set of activities that enterprise perform to optimize their

business processes such as accounting and finance, hiring employees and purchasing goods and services.

BPM almost aided by specialized software designed to assist in these activities.

o Business process automation (BPA) Provide easy exchange of information among business applications,

reduce the need for human intervention in process and utilizes software to automate processes wherever possible.

BPS offers greater efficiency and reduces risks by making processes more predictable.

Information system in the enterprise

An information system is a set of hardware, software, data, people and procedures that work together to produce information.

Enterprise-wide technologies and methodologies

The technology used in enterprise are:1. portal

Collection of links, content, and services presented on Web page Designed to guide users to information they are likely to find interesting

for a particular job function


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2. electronic communications infrastructure3. data warehouses

Huge database that stores data required to analyze historical and current transactions


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4. extranets Portion of network that allows customers or suppliers to access parts of

enterprise’s intranet Replaces or supplements existing EDI systems

5. web services Technologies that allow businesses to create products and B2B (business-

to-business) interactions

6. workflow Steps involved in completing project or business process Workflow application is a program that tracks process from start to finish

7. virtual private network Provides secure connection for user connecting to company network

server using Internet


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