Essential Introduction to Computers Notes

B a s i c I n f o r m a t i o n T e c h n o l o g y C o n c e p t s

E S S E N T I A L I N T R O D U C T I O N T O C O M P U T E R S

Objectives

 Define the term computer and discuss the four basic computer operations: input, processing, output, and storage

 Define data and information

 Explain the principle components of the computer and their use

 Describe the use and handling of floppy disks and hard disks

 Discuss computer software and explain the difference between system software and application software

 Identify several types of personal computer application software

 Discuss computer communications channels and equipment and the Internet and World Wide Web

 Explain how to purchase, install, and maintain a personal computer, a notebook computer, and a handheld computer

 Define e-commerce

C o m p u t e r : I n p u t , P r o c e s s i n g , O u t p u t , a n d S t o r a g e

In today's world, computers are used for almost every task imaginable. Routine activities such as paying bills, buying groceries, or communicating with a friend can be done with a computer. That is why it is important not only to know how to use a computer, but also to understand the components of a computer and what they do.

Recent studies report that almost 40% of homes surveyed have personal computers, and this number is growing. Given the widespread use of computers, computer literacy - a knowledge and understanding of computers and computer uses - has become an essential ingredient in the recipe for success in today's world. Florida was the first state to demand computer literacy of all students by grade 12.

Collectively, the electric, electronic, and mechanical equipment that makes up a personal computer is called hardware. Devices that surround the system unit (i.e., the keyboard, mouse, speakers, monitor, and so on) sometimes are known as peripheral devices.

Computers manipulate (process) data (input) to produce information (output) and hold (store) that information for future use. These operations are completed incredibly quickly. Today's supercomputer can perform 72 trillion operations per second. If a person did one arithmetic operation a second without stopping, it would take more than 31,000 years to perform the number of operations a supercomputer can do in one second.

D a t a a n d I n f o r m a t i o n

A major part of understanding computers is to know what goes into them (data), what comes out of them (information), and to understand the process of turning data into information, also known as the information processing cycle.

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Understanding the difference between data and information is important. Clifford Stoll - lecturer, computer security expert, and author (The Cuckoo's Egg: Tracking a Spy through the Maze of

Computer Espionage and Silicon Snake Oil: Second Thoughts on the Information Superhighway are two of his most popular works) - notes a wide gap between data and information. Information has a pedigree, or lineage. Its source is known, whether a respected professor or a seventh grader. "The

Internet has great gobs of data," Stoll maintains, "and little, little information."

C o m p o n e n t s o f t h e C o m p u t e r a n d T h e i r U s e

A computer consists of five primary hardware components: input devices, the central processing unit

(CPU), memory, output devices, and storage devices. These components work together with software to perform calculations, organize data, and communicate with other computers.

Different types of input devices transmit different types of data or transmit data in different ways. A keyboard is used to transmit alpha/numeric data by typing. In addition to the standard keys in the typing area, an enhanced keyboard contains:

Function keys that can be programmed to perform specific tasks

Status lights that indicate modes that can be turned on and off by toggle keys (e.g., caps lock and num lock)

A numeric keypad that allows for rapid entry of numbers

Arrow keys and other cursor-control keys (e.g., home, end, page up, and page down) that control the on-screen movement of the insertion point

Special keys such as esc, shift, ctrl, and alt that have varying functions depending on the software

The mouse , like a trackball or joystick, is called a pointing device because it controls the movement of a pointer, or mouse pointer, on the computer screen. The first mouse was a one-button, rectangle shaped device invented by Doug Engelbart in 1964. A mouse is very easy to use. It requires empty desk space, however, and forces the user to remove a hand from the keyboard to give a command.

Different CPUs function at different speeds. The rate at which computer operations take place is measured in gig hertz (GHz), or billions of electronic pulses per second. This rate varies among computers and should be a consideration when purchasing a personal computer. Computers have two basic types of memory. RAM (random access memory) is volatile, meaning that its contents are lost when the computer is turned off. ROM (read-only memory) is non-volatile because it retains its contents even when the power is turned off. ROM stores information that does not change, such as the instructions and data used to start the computer when it is first turned on.

Like input devices, different types of output devices convey different types of information or convey information in different ways. Printer output sometimes is called hard copy because of its physical, touchable character. Monitor output, on the other hand, is called soft copy because it has only an electronic, intangible existence.

Non-impact printers represent the fastest growing segment of the printer market. The drops of ink that form an ink-jet printer character are similar to the dots that form a dot matrix character figure, but there are many more of them. Good quality paper must be used with ink-jet printers so that the ink does not bleed. The speed quoted for impact printers often is measured in characters per second (cps).

Like ink-jet printers, laser printer speed is measured in pages per minute (ppm). Although they are fast, all printers are much slower than computers. Because of this, most printers have a buffer that temporarily stores a few pages, allowing the computer to dump output into the buffer and continue processing. The most widely used PC monitors are 14- or 17-inch (measured from one corner to the

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B a s i c I n f o r m a t i o n T e c h n o l o g y C o n c e p t s diagonally opposite corner). With the growing popularity of portable computers, the clarity of LCD displays continues to improve. The quality of a monitor's display depends largely on three factors:

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Resolution - the number of pixels displayed

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Dot pitch - the distance between pixels

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Refresh rate - the speed with which images are redrawn on the screen

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Storage devices are different from memory. Memory, sometimes called primary storage, is fast, short-term, volatile, and relatively expensive. Storage devices, on the other hand, are slower, longterm, non-volatile, and less expensive.

F l o p p y D i s k s a n d H a r d D i s k s

The data and information used in a computer needs to be stored for future use. The memory of a computer only holds items temporarily while they are being processed. When not being processed, these items must be stored in auxiliary storage devices. These devices include floppy disks, hard disks,

CD-ROM, and DVD-ROM. When selecting a storage device it is important to know that each device holds different amounts of information.

Although floppy disks once were available in two sizes, the 5.25-inch floppy disk rarely is used today, and some believe it is destined for the same fate as the eight-track tape. Because of its rigid plastic shell, it may be difficult to see the 3.5-inch disk as "floppy." The name is justified, however, not only by the disk's ancestry but also by the flexible character of the disk itself. When a floppy disk drive is reading from or writing to a floppy disk, a light turns on next to the drive. Floppy disks never should be inserted into or removed from the drive when this light is on. Most magnetic disks are read/write storage media. Some optical discs, such as CD-ROMs, usually can be read from but not written to.

Each track on a formatted floppy disk is very narrow. To see how narrow, try to draw 80 lines in a

11/4-inch space (the approximate radius of the floppy disk surface). Floppy disks are soft-sectored, meaning that the number of sectors is not predetermined. Floppy disk access time depends on the time needed to locate the correct track, the time required to rotate the disk to the proper sector, and the time necessary to transfer the data into main memory.

Although personal computer hard disks usually are fixed (i.e., not removable), some portable computers have removable hard disk drives. Unlike floppy disks, hard disks constantly are spinning, at a rate 10 to 20 times faster than floppy disks. Therefore, access time for hard disks is significantly less than access time for floppy disks. While a floppy disk read/write head rests on the disk, the read/write head for a hard disk hovers about 10 millionths of an inch above the disk surface. Contamination on the disk - a speck of dust (about 1550 millionths of an inch), a fingerprint (about 600 millionths of an inch), or a particle of smoke (about 250 millionths of an inch) - can cause a "head crash," destroying data and rendering the disk drive unusable. For this reason, hard disk drives are sealed and manufactured in an environment that typically is cleaner than a hospital operating room. Storage capacity can be increased on both hard disks and floppy disks with compression programs such as

Stacker, WinZip, or PKZIP.

C o m p u t e r S o f t w a r e : S y s t e m S o f t w a r e a n d A p p l i c a t i o n S o f t w a r e

There are two categories of computer software: system software and application software. System software serves as the interface between a user and the computer's hardware. An example of system software would be an operating system such as Microsoft Windows. Application software consists of programs designed to perform specific tasks. An example of application software would be a spreadsheet program, such as Microsoft Excel.

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A 3.5-inch floppy disk is computer hardware, but the programs stored on it are computer software.

Although there are two types of software, system software and application software are designed to work hand-in-glove; that is, application software packages are designed to work with specific kinds of system software. By telling the computer how to perform common functions, the operating system frees application software to concentrate on producing information. Popular operating systems include

Windows, the Mac OS, OS/2, UNIX, Linux, DOS, and NetWare. Operating systems that have a graphical user interface (GUI) often are called user-friendly. Studies have found that GUI users generally complete tasks more accurately, work faster, are more productive, and feel less fatigue.

To understand the relationship between application software and system software, draw four concentric circles. Label the innermost circle CPU, the next operating system, the next application software, and the last user. The resultant diagram illustrates how the operating system helps to insulate the user and application program from computer hardware.

T y p e s o f P e r s o n a l C o m p u t e r A p p l i c a t i o n S o f t w a r e

Many types of application software are available. The more popular application software includes word processing software, electronic spreadsheet software, database software, presentation graphics software, communications software, and electronic mail software. Knowing the function of each type of application software is one of the most important ingredients of being computer literate.

Several years ago, a survey of large and small businesses showed that the most often used applications were:

 Word processing and spreadsheet (used by 100% of those surveyed)

 Communications, electronic mail, database, and presentation graphics (used by about 95%)

 Desktop publishing (used by about 85%)

 Project management (used by about 70%)

 Personal information management (used by about 50%)

In word processing , any work developed through the writing process is a document. Word processing software makes it easier to create, edit, format, and print documents. Many word processing packages include a spell checker, grammar checker, and thesaurus.

The first spreadshee t software, VisiCalc, was introduced in 1979. By immediately displaying the results of changes, electronic spreadsheet packages provide a capability called what-if analysis.

Another powerful capability, called goal-seek, finds what value is needed to reach a specified goal.

A database file is a collection of related data called records, each of which consists of a group of related facts called fields. The data can be manipulated, or a report, called a query, can be created based on user-specified criteria. Although most spreadsheet packages can manage data tables of a few thousand records, database software can efficiently handle much larger data tables.

Word processing and spreadsheet software came out around 1980. Presentation graphics software was not introduced until the mid to late 1980s. Nevertheless, it can be argued that presentation graphics software has had almost as great an impact on business, and on how people do business, as either of the older applications. Presentation graphics packages include libraries of clip art that can be inserted into slides and a slide sorter that can be used to organize the order effectively in which slides are presented.

C o m p u t e r C o m m u n i c a t i o n s C h a n n e l s a n d E q u i p m e n t a n d t h e

I n t e r n e t a n d W o r l d W i d e W e b

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Communicating with a computer is becoming the standard today for both business and personal use.

The communications channels are constantly being upgraded in order to send information faster.

Communications technologies have changed the way people interact through the use of e-mail, videoconferencing, and the Internet.

Many vendors sell network versions of their software. The network version resides on the network server and can be accessed by each computer on the network. When a network version is purchased, a site license is obtained from the vendor. The fee for the site license, usually based on the number of computers on the network, is less than the purchase of individual packages for each computer.

The number of people using the Internet is growing by 5% each month. Paul Moritz, a vice president at Microsoft, maintains that, "In the long run, it's hard to exaggerate the importance of the Internet."

The Web, an innovation of Tim Berners-Lee, debuted in 1989. Since then, the Web has experienced astounding growth. Some experts claim that the size of the Web doubles every 60 days. Using links to move from one document to another often is called surfing the Web. Two popular Web browsers are

Netscape Navigator and Microsoft Internet Explorer.

H o w t o P u r c h a s e , I n s t a l l , a n d M a i n t a i n a C o m p u t e r

At some point in your life, you will probably decide to purchase a computer. Aside from understanding the components discussed earlier, it also is important to be able to find the computer that best fits your needs. For example, most new computers come with application software already installed. If you do not use this software, then it is of no value even though you got it for "free." There are several things to look for when purchasing a new computer. If possible, speak to someone who is familiar with the purchasing process and can guide you along.

For most people, buying a computer is an expensive experience. Despite this, many people are woefully uninformed when they set out to purchase a computer. Although desktop computer systems remain popular, since 1993 sales of laptop, notebook, and smaller computers have rivalled sales of larger systems, partly because of their enhanced capabilities and increased use by field sales forces. Be careful when setting up a computer system. Failure to follow health guidelines can lead to painful, and even permanent, disabilities. Government studies indicate repetitive stress disorder (RSI) and cumulative trauma disorder (CTD), the most commonly reported problems associated with prolonged keyboard use, are responsible for half of work-related illnesses. Computer security is an increasingly important issue. A survey of American companies with more than 200 personal computers showed that over 60% had suffered at least one virus attack. Two of the major sources of viruses, free software and illegally copied software, more commonly are used by small companies and private individuals, so the percentage of PC users affected by viruses may be much higher. E-mail attachments have been the carriers of several recent virus attacks that have infected both business and home computer users.

E - C o m m e r c e

Conducting business online is known as electronic commerce, or e-commerce, and includes such commercial activities as shopping and investing. The three types of e-commerce that exist today are business to consumer (B2C), consumer to consumer (C2C), and business to business (B2B).

If you have access to a computer, an Internet connection, and a means to pay for products or services, you can participate in e-commerce. Today, users can participate in e-commerce not only through desktop computers, but also through mobile devices such as laptop and handheld computers, pagers, and cellular phones. M-commerce (mobile commerce) is the term some people use to describe ecommerce activities that take place using mobile devices.

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The more popular uses of e-commerce include shopping and investing. On the Web, you can buy and sell stocks, order flowers, purchase groceries and airline tickets, and even buy a car!

Three types of e-commerce exist: business to consumer (B2C), consumer to consumer (C2C), and business to business (B2B). Of the three, most e-commerce takes place between businesses, making

B2B e-commerce transactions the most common.

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C H A P T E R 1 : I N T R O D U C T I O N T O C O M P U T E R S

Overview

 Explain the importance of computer literacy

 Define the term computer

 Identify the components of a computer

 Explain why a computer is a powerful tool

 Differentiate among the various types of software

 Explain the purpose of a network

 Discuss the uses of the Internet and the World Wide Web

 Describe the categories of computers and their uses

 Identify the various types of computer users

 Understand how a user can be a Web publisher

This chapter presents a broad survey of concepts and terminology related to computers. The idea of computer literacy is introduced. You discover what a computer is and what it does. You learn about the components of a computer, the power of computers, computer software, and networks and the

Internet. Categories of computers are identified, including personal computers, minicomputers, mainframe computers, and supercomputers.

You discover how people employ computers, from home users to large business users. Finally, you learn how people use computers to provide information. Reading and understanding the material in this chapter should help you better understand these topics as they are presented in more detail in the following chapters.

E x p l a i n t h e i m p o r t a n c e o f c o m p u t e r l i t e r a c y

Computers have touched every part of our lives: the way we work, the way we learn, the way we live, even the way we play. It almost is impossible to go through a single day without encountering a computer, a device dependent on a computer, information produced by a computer, or a word that was introduced or whose meaning has changed with the advent of computers. Because of the significance of computers in today’s world, it is important to be computer literate. Being computer literate means you have knowledge and understanding of computers and their uses.

D e f i n e t h e t e r m c o m p u t e r

A computer is an electronic machine, operating under the control of instructions stored in its own memory that can accept data, manipulate the data according to specified rules, produce results, and store the results for future use.

Computers process data to create information.

Data is a collection of raw unprocessed facts, figures, and symbols.

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

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To process data into information, a computer uses hardware and software.

Hardware is the electric, electronic, and mechanical equipment that makes up a computer.

Software is the series of instructions that tells the hardware how to perform tasks.

I d e n t i f y t h e c o m p o n e n t s o f a c o m p u t e r

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

An input device is any hardware component that allows a user to enter data and instructions into a computer. Six commonly used input devices are the keyboard, mouse, microphone, scanner, digital camera, and PC camera.

An output device is any hardware component that can convey information to a user. Three commonly used output devices are a printer, a monitor, and speakers.

The system unit is a box-like case made from metal or plastic that protects the internal electronic components of the computer from damage. The system unit contains the central processing unit and memory. The central processing unit (CPU) is the electronic device that interprets and carries out the basic instructions that operate the computer. Memory is a temporary holding place for data and instructions.

A storage device records and retrieves data to and from a storage medium. Six common storage devices are a floppy disk drive, a Zip® drive, a hard disk drive, a CD-ROM drive, a CD-RW drive, a

DVD-ROM drive, and a DVD+RW drive.

A communications device enables computer users to communicate and exchange items such as data, instructions, and information with another computer. A modem is a communications device that enables computers to communicate usually via telephone lines or cable.

E x p l a i n w h y a c o m p u t e r i s a p o w e r f u l t o o l

A computer is a powerful tool because it is able to perform the information processing cycle operations (input, process, output, and storage) with amazing speed, reliability, and accuracy; store huge amounts of data and information; and communicate with other computers. Computers allow users to generate correct information quickly, hold the information so it is available at any time, and share the information with other computer users.

D i f f e r e n t i a t e a m o n g t h e v a r i o u s t y p e s o f s o f t w a r e

There are two categories of computer software: system software and application software.

System software consists of the programs that control the operations of a computer and its devices.

Two types of system software are the operating system and utility programs.

An operating system (OS) coordinates all activities among hardware devices and contains instructions that allow you to run application software.

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A utility program performs specific tasks, usually related to managing a computer, its devices, or its programs. You interact with software through its user interface.

Application software consists of programs that perform specific tasks for users. Popular application software includes word processing software, spreadsheet software, database software, and presentation graphics software. Application software can be

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Packaged software (copyrighted software that meets the needs of a variety of users),

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In-house/Custom software (tailor-made software developed at a user’s request),

 Freeware (copyrighted software provided at no cost),

Public-domain software (software donated for public use with no copyright restrictions), or

Shareware (copyrighted software distributed free for a trial period).

E x p l a i n t h e p u r p o s e o f a n e t w o r k

A network is a collection of computers and devices connected together via communications devices, such as a modem, and communications media, such as cables, telephone lines, cellular radio, and satellites. Networks allow users to share resources, such as hardware devices, software devices, data, and information. Most business computers are networked, either by a local area network (LAN) in a limited geographic area or by a wide area network (WAN) in a large geographical area.

D i s c u s s t h e u s e s o f t h e I n t e r n e t a n d t h e W o r l d W i d e W e b

The world’s largest network is the Internet, which is a worldwide collection of networks that links together millions of businesses, government agencies, educational institutions, and individuals. Users connect to the Internet to send messages, access information, shop for goods and services, meet or converse with other users, and access sources of entertainment and leisure. Most users connect to the

Internet through an Internet service provider (ISP) or an online service provider (OSP). The World

Wide Web is a popular segment of the Internet that contains billions of documents called Web pages.

These documents can contain text, graphics, sound, video, and built-in connections, or links, to other

Web pages stored on computers throughout the world.

D e s c r i b e t h e c a t e g o r i e s o f c o m p u t e r s a n d t h e i r u s e s

The six major categories of computers are personal computers, handheld computers, Internet appliances, mid-range servers, mainframes, and supercomputers. These categories are based on differences in size, speed, processing capabilities, and price.

A personal computer can perform all of its input, processing, output, and storage activities by itself.

Personal computers include desktop computers and notebook computers.

A desktop computer is designed so the system unit, input devices, output devices, and any other devices fit entirely on or under a desk or table. Variations of desktop computers include

 Tower models (computers with tall and narrow system units that can sit vertically on the floor),

 All-in-one computers (less expensive computers that combine the monitor and system unit into

 a single device), and

Workstations (more expensive and powerful computers designed for work that requires intense calculation and graphics capabilities).

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A notebook computer is a portable personal computer small enough fit on your lap. Notebook and desktop computers are used at home or in the office to perform application software-related tasks or to access the Internet.

A handheld computer is a small computer that fits in your hand. Handheld computers can perform specific, industry-related functions, or can be general-purpose. A PDA (personal digital assistant) is a handheld computer that provides personal organizer functions, such as a calendar, appointment book, and notepad.

An Internet appliance is a computer with limited functionality whose main purpose is to connect to the

Internet from home.

A mid-range server is more powerful and larger than a workstation computer. Users typically access a mid-range server through a personal computer or a terminal, which is a device with a monitor and a keyboard that usually has no stand-alone processing power.

A mainframe is a large , expensive, very powerful computer that can handle hundreds or thousands of connected users simultaneously.

A supercomputer is the fastest, most powerful, and most expensive category of computer.

I d e n t i f y t h e v a r i o u s t y p e s o f c o m p u t e r u s e r s

Computer users can be divided into five categories: home user, small office/home office users, mobile users, large business users, and power users.

A home user spends time on the computer for personal and business communications, budgeting and personal financial management, entertainment, and Web access.

A small office/home office (SOHO) user includes any company with fewer than 50 employees, as well as self-employed people that work out of their home.

A mobile user travels to and from a main office or school to conduct business, communicate, or do homework.

A large business user works for a company that has a large number of employees and computers usually connected to a network.

The power user – such as an engineer, architect, or desktop publisher – typically works with multimedia, which combines several media elements into one application, and requires the capabilities of a workstation or other powerful computer.

U n d e r s t a n d h o w a u s e r c a n b e a W e b p u b l i s h e r

In addition to being a recipient of information, Internet users have the ability to provide information to other connected users around the world. Users can create a Web page with word processing software or with Web page authoring software. Publishing a Web page is the process of making it available on the Internet.

Expand Your Knowledge

 Computer literacy

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Computer

Computer components

Computer power

Computer software

Networks

The Internet

Computer categories

Types of computer users

Web publishing

Here you will find additional information that will expand and enhance your knowledge beyond that contained in your textbook. Compare this information to what may be provided in a traditional classroom by your instructor or peers.

C o m p u t e r L i t e r a c y

It is difficult to think of a field in which computers are not used. In addition to general-purpose computers, special-purpose computers are used in everything from automobiles to electric razors.

Consider how computers have influenced our daily lives, both positively and negatively. (“To err is human, but to really foul things up requires a computer.” – Anonymous, from a BBC Radio broadcast.) List ways in which computers are being used today. What is the most common use? What is the most unusual use? As a result of the expanding use of computers, in 1986 Florida became the first state to demand computer literacy of all students by grade 12.

C o m p u t e r

Although computers are thought of as a relatively recent innovation, the term computer has a long history. Prior to 1940, “computer” was a job title that referred to anyone performing calculations.

Consider how data is different from information. Data is processed into information. Clifford Stoll – lecturer, computer security expert, and author of Silicon Snake Oil: Second Thoughts on the

Information Superhighway – notes a wide gap between data and information. Stoll insists that information has a pedigree, or lineage. Its source is known, whether by a respected professor or a seventh grader. “The Internet has great gobs of data,” Stoll maintains, “and little, little information.”

The first three operations in the information processing cycle — input, process, and output — are performed to process data into information, while the fourth operation — storage — refers to a computer’s electronic reservoir capability. Think about how we perform each phase in the information processing cycle in the “human computer” (i.e., the human brain) while completing a common task, such as learning a telephone number.

C o m p u t e r C o m p o n e n t s

Different types of input devices are designed to transmit different types of data or to transmit data in different ways. Think of other input devices (joysticks, scanners, digital cameras, and so on) and the different types of data they transmit or the different ways they transmit data.

Because it is more lasting than output from a monitor or speaker, the printer’s output often is called hard copy. Think of other output devices with which you are familiar (data projectors, computer output microfilm, and so on).

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Some computer components are considered internal, while others are considered external. External components are called peripherals. Input, output, and communications devices often are peripheral devices.

The difference between the temporary character of memory and permanent nature of storage will be made painfully clear the first time you experience a power failure while working on a computer. Think of other examples of storage devices (magnetic tape, PC Cards, and so on).

The capability to communicate may be one of the most significant factors influencing how computers are used now and in the future.

C o m p u t e r P o w e r

In one billionth of a second, an electronic signal travels almost 12 inches. This means that today’s supercomputer (the fastest, most powerful, and most expensive category of computers) can perform

1.8 trillion operations per second. If a person did one arithmetic operation a second without stopping, it would take more than 31,000 years to perform the number of operations a supercomputer can do in one second. Researchers predict that one day computer speed will be measured in exaflops, or one quintillion (1 x 1018) calculations per second.

The reliability of computer components often is measured in MTBF (mean time between failure, in hours). A typical component might be rated 10,000 MTBF.

Although the term “computer error” is widespread, most computer errors can be traced to human mistakes. Consider instances of computer error with which you are familiar. How might human blunders have resulted in the computer error? Why are people apt to blame computers?

Supercomputers have more than 600 gigabytes of memory, meaning that they can store more than 600 billion letters, numbers, and special characters, and have 2 terabytes (2 trillion bytes) of disk space.

Equally important is the speed at which data can be retrieved, processed, and stored again.

Connected computers can share each operation in the information processing cycle. To recognize the value of communication, imagine trying to solve a problem individually, and then trying to solve the same problem with the assistance of several classmates.

C o m p u t e r S o f t w a r e

The difference between computer hardware and computer software is important. A 3½-inch floppy disk is hardware; however the programs stored on it are software. Programs or software, like data, are input into the computer.

Because you interact with it directly, you may be more consciously aware of application software than system software. Remember that system software determines how you interact with application software. Popular operating systems include DOS (Disk Operating System), Windows 3.x (technically, not an operating system but an operating environment that makes DOS easier to use), Windows 95,

Windows 98, Windows 2000, Windows XP, Mac OS, OS/2, UNIX, Linux (rhymes with cynics), and

NetWare. DOS was developed by Microsoft for IBM personal computers. DOS started Microsoft’s climb to the top of the software world -- at one time, versions of DOS were used worldwide by more than 100 million people. DOS has a command-line interface, meaning that people have to memorize and type instructions.

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Today, operating systems with a graphical user interface, such as Microsoft’s Windows, are far more popular.

Most application software packages are designed to be used with specific operating systems. Much of the software with which you are familiar is packaged software. Because of their complexity, most software programs are written by teams of programmers working together. Just as people understand a variety of spoken languages (English, French, Chinese, and so on), computers recognize a number of programming languages.

N e t w o r k s

A network with which you might be familiar is the school computer lab. Consider resources that can be shared on a network. For example, the school computer lab may share a single printer. Think of advantages of sharing resources. Why are most business computers part of a network?

T h e I n t e r n e t

Estimates claim that more than 50 percent of U.S. homes are connected to the Internet, and more than

13 million do so through an online service provider. Although the growth rate of the Internet and online services has slowed from a peak of more than 140 percent in 1994-95, the growth rate still is around 20 percent annually. Surveys show the number of Web site visitors continues to expand rapidly, practically doubling every year. Interestingly, surveys show that teenage boys and girls are accessing the Internet for different reasons. While boys seem to focus on entertainment, girls use the

Internet more for schoolwork and chat.

C o m p u t e r C a t e g o r i e s

In addition to differences in size, speed, processing capabilities, and price, other factors, such as the size of main memory and number of peripheral devices, also can be considered when categorizing computers. Rapid changes in technology make it difficult to define categories precisely. As a rule of thumb, today’s PCs have about as much memory and processing power as the mainframes of a decade ago.

Think of personal computers with which you are familiar. How is the computer used? What factors influence the choice of a personal computer? In addition to such obvious considerations as processing speed and amount of memory, less apparent factors, such as available software or even the computer’s

“footprint” (the amount of space it occupies on the work surface) also may be important. A desktop computer monitor often is placed on top of the system unit case. This sometimes can be an ergonomic problem, forcing users to look up. Server computers often are used in academic environments. What features of server computers would make them particularly attractive to schools? In today’s mobile society, notebook computers have become indispensable tools. Since 1993, sales of notebooks and smaller computers have rivalled sales of larger systems, partly because of their enhanced capabilities and increased use by field sales forces. The capabilities of handheld computers also continue to expand. Visor, a new handheld computer from Handspring, is an electronic organizer but also offers video games, a cell phone, a modem, an MP3 player, and a two-way pager. Called the “Swiss Army knife of handheld computers,” Visor uses the Palm operating system, which is the same operating system used by the Palm Pilot, a popular handheld computer from 3Com, and is available for about

$200.

The growing movement toward decentralization in business, coupled with the increasing power of mid-range servers, has led to a recent trend away from mainframe computers and toward mid-range servers. What advantages might mid-range servers have over mainframe computers for a business?

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Organizations that deal with huge, constantly changing collections of data accessed simultaneously by many users, such as banks, insurance companies, universities, and government agencies, often use mainframe computers. Despite this, mainframe sales are declining approximately 10 percent per year.

One of the most important features of supercomputers is their capability to create complex, threedimensional images almost instantaneously. Television networks often use supercomputers to generate complicated images and then give viewers the sense of “going through” the image. Due to their size and expense, only large businesses and government agencies use supercomputers. IBM’s Option Blue supercomputer was used by the Department of Energy to simulate nuclear explosions, allowing the effects of aging and adverse conditions on nuclear weapons to be explored without underground detonations.

T y p e s o f C o m p u t e r U s e r s

A major concern related to the home user is the digital divide, which is the idea that the people of the world can be separated into two distinct groups: those that have access to technology with the ability to use it and those that do not have access to technology or are without the ability to use it. Recent reports suggest that the digital divide exists on several levels:

Individuals in higher income levels have greater access to the Internet than people in lower levels and the gap may be growing.

Women are under-represented in today’s computer classes and technology jobs.

A number of efforts are being made to narrow the digital divide.

Networks have changed the face of both small and large business. In the 1970s, executives usually worked with monthly reports; in the 1980s, they used weekly reports; today, daily or even hourly reports are available. How have computers affected the efficiency of businesses? What impact have computers had on the “interpersonal” side of business (i.e., employee and customer relationships)?

How have computers changed people’s jobs? Have computers cost any people their jobs?

W e b P u b l i s h i n g

With today’s Web page authoring software, children as young as 10 years old, and sometimes younger, can create and publish their own Web pages. If you created a Web page, what type of information would you provide? Why? Would you be interested in seeing someone else’s Web page?

Why or why not? If you have created a Web page, what type of software did you use? What was the most difficult part of creating your Web page?

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C H A P T E R 2

T H E I N T E R N E T A N D W O R L D W I D E W E B

Overview

 Discuss how the Internet works

 Understand ways to access the Internet

Identify a URL 





Search for information on the Web

Describe the types of Web pages

Recognize how Web pages use graphics, animation, audio, video, and virtual reality 

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Define Webcasting

Describe the uses of electronic commerce (e-commerce)





Explain how e-mail, FTP, newsgroups and message boards, mailing lists, chat rooms, and instant messaging work

Identify the rules of netiquette

This chapter introduces one of the most significant innovations of the past half century – the Internet.

The Internet is defined, and the history of the Internet is detailed. You discover how the Internet works and learn about Internet service providers and online services, connecting to the Internet, how data travels the Internet, and Internet addresses. The World Wide Web, search engines, and multimedia on the Web are explained. You become familiar with Webcasting, electronic commerce, Web publishing, and other Internet services including e-mail, FTP, Telnet, newsgroups, mailing lists, chat rooms, instant messaging and VOIP. Finally, netiquette, the Internet code of acceptable behaviour by users, is described.

D i s c u s s h o w t h e I n t e r n e t w o r k s

The Internet is a worldwide collection of networks that links millions of businesses, government offices, educational institutions, and individuals. Data is transferred over the Internet using servers, which are computers that manage network resources and provide centralized storage areas, and clients, which are computers that can access the contents of the storage areas. The data travels over communications lines. Each computer or device on a communications line has a numeric address called an IP (Internet protocol) address, the text version of which is called a domain name. Every time you specify a domain name, a DNS (domain name system) server translates the domain name into its associated IP address, so data can route to the correct computer.

U n d e r s t a n d w a y s t o a c c e s s t h e I n t e r n e t

You can access the Internet through an Internet service provider, an online service provider, or a wireless service provider.

An Internet service provider (ISP) provides temporary Internet connections to individuals and companies.

An online service provider (OSP) also supplies Internet access, in addition to a variety of special content and services.

A wireless service provider (WSP) provides wireless Internet access to users with wireless modems or

Web-enabled handheld computers or devices.

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Employees and students often connect to the Internet through a business or school network that connects to a service provider. For home or small business users, dial-up access provides an easy and inexpensive way to connect to the Internet.

With dial-up access, you use a computer, a modem, and a regular telephone line to dial into an ISP or

OSP. Some home and small business users opt for newer, high-speed technologies.

DSL (digital subscriber line) provides high-speed connections over a regular copper telephone line.

A cable modem provides high-speed Internet connections through a cable television network.

I d e n t i f y a U R L

The most widely used service on the Internet is the World Wide Web. The World Wide Web (WWW or Web) consists of a worldwide collection of electronic documents called Web pages. A browser is a software program used to access and view Web pages. Each Web page has a unique address, called a

URL (Uniform Resource Locator) that tells a browser where to locate the Web page. A URL consists of a protocol, domain name, and sometimes the path to a specific Web page or location on a Web page. Most URLs begin with http://, which stands for hypertext transfer protocol, the communications standard that enables pages to transfer on the Web.

S e a r c h f o r i n f o r m a t i o n o n t h e W e b

A search engine is a software program you can use to find Web sites, Web pages, and Internet files. To find a Web page or pages, you enter a relevant word or phrase, called search text or keywords, in the search engine’s text box. Many search engines then use a program called a spider to read pages on

Web sites and create a list of pages that contain the keywords. Any Web page that is listed as the result of the search is called a hit. Each hit is a link that can be clicked to display the associated Web site or

Web page.

D e s c r i b e t h e t y p e s o f W e b p a g e s

There are six basic types of Web pages.

An advocacy Web page contains content that describes a cause, opinion, or idea.

A business/marketing Web page contains content that promotes or sells products or services.

An informational Web page contains factual information.

A news Web page contains newsworthy material including stories and articles relating to current events, life, money, sports, and the weather.

A portal Web page offers a variety of Internet services from a single, convenient location.

A personal Web page is maintained by a private individual who normally is not associated with any organization.

R e c o g n i z e h o w W e b p a g e s u s e g r a p h i c s , a n i m a t i o n , a u d i o , v i d e o , a n d v i r t u a l r e a l i t y

Many exciting Web pages use multimedia. Multimedia refers to any application that integrates text with one of the following elements: graphics, sound, video, virtual reality, or other media elements.

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A graphic is a digital representation of information such as a drawing, chart, or photograph. Two common file formats for graphical images on the Web are JPEG (Joint Photographic Experts Group) and GIF (Graphics Interchange Format), which use compression techniques to reduce the size of graphics files and thus speed downloading.

Animation is the appearance of motion created by displaying a series of still images in rapid sequence.

One popular type of animation, called an animated GIF, uses computer animation and graphics software to combine several images into a single GIF file.

Audio is music, speech, or any other sound. A common format for audio files on the Web is MP3, a popular technology that compresses audio. More advanced Web audio applications use streaming audio, which transfers audio data in a continuous and even flow, allowing users to listen to the sound as it downloads.

Video consists of full-motion images that are played back at various speeds. Video files often are quite large in size. The Moving Pictures Experts Group (MPEG) defines a popular video compression standard. Streaming video allows you to view longer or live video images as they are downloaded.

Virtual reality (VR) is the use of computers to simulate a real or imagined environment that appears as a three-dimensional (3-D) space. A VR world is an entire 3-D site that contains infinite space and depth.

D e f i n e W e b c a s t i n g

Pull technology is a method of obtaining information that relies on a client such as your computer to request a Web page from a server. On the other hand, Webcasting, also called push technology, is a method of obtaining information in which a server automatically downloads content to your computer at regular intervals or whenever updates are made to the site. Webcasting saves time by delivering information at regular intervals and allows users to view Web content when they are offline, that is, when they are not connected to the Internet.

D e s c r i b e t h e u s e s o f e l e c t r o n i c c o m m e r c e ( e - c o m m e r c e )

Electronic commerce (e-commerce) is a financial business transaction that occurs over an electronic network such as the Internet. Today, there are three types of e-commerce.

Business to consumer (B-to-B or B2C) e-commerce consists of the sale of goods to the general public.

Customers visit an online business through an electronic storefront, which contains descriptions, graphics, and a shopping cart that allows customers to collect their purchases.

Consumer to consumer (C-to-C or C2C) e-commerce occurs when one consumer sells directly to another. An online auction is an example of consumer to consumer e-commerce.

Business to business (B-to-B or B2B) e-commerce, which is the most prevalent type of e-commerce, takes place between businesses, with businesses typically providing services to other businesses.

E x p l a i n h o w e - m a i l , F T P , n e w s g r o u p s a n d m e s s a g e b o a r d s , m a i l i n g l i s t s , c h a t r o o m s , a n d i n s t a n t m e s s a g i n g w o r k

A variety of services are used widely on the Internet, including e-mail, FTP, newsgroups and message boards, mailing lists, chat rooms, and instant messaging.

E-mail (electronic mail) is the transmission of messages and files via a computer network. You use an e-mail program to create, send, receive, forward, store, print, and delete messages. To receive

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B a s i c I n f o r m a t i o n T e c h n o l o g y C o n c e p t s messages, you need an e-mail address, which is a combination of a username and a domain name that identifies a user.

FTP (File Transfer Protocol) is an Internet standard that allows you to upload and download files with other computers on the Internet. An FTP server is a computer that allows you to use FTP to upload files to, and download files from, an FTP site. With anonymous FTP, anyone can transfer some, if not all, available files.

A newsgroup is an online area in which users conduct written discussions about a particular subject.

The computer that stores and distributes newsgroup messages is called a news server. You use a program called a newsreader to access a newsgroup, read previously entered messages (called articles), and add (post) messages of your own. A thread consists of the original article and all subsequent related replies. In a moderated newsgroup, a moderator reviews articles and posts them, if appropriate.

A message board is a popular Web-based type of discussion group that does not require a newsreader and typically is easier to use than a newsgroup.

A mailing list is a group of e-mail names and addresses given a single name. To add your e-mail name and address to a mailing list you subscribe to it; to remove your name, you unsubscribe.

A cha t is real-time (meaning everyone involved in the chat is online at the same time) typed conversation that takes place on a computer. A location on an Internet server that permits users to chat is called a chat room. Some chat rooms support voice chats and video chats, where you can hear or see others and they can hear or see you as you chat. A chat client is a program on your computer that allows you to connect to a chat server and start a chat session.

Instant messaging (IM) is a real-time Internet communications service that notifies you when one or more people are online and then allows you to exchange messages or join a private chat room.

I d e n t i f y t h e r u l e s o f n e t i q u e t t e

Netiquette, which is short for Internet etiquette, is the code of acceptable behaviours users should follow while on the Internet. Rules for e-mail, newsgroups, and chat rooms include:







 Keep messages brief and use proper grammar and spelling.





Be careful when using sarcasm and humour.

 Be polite and avoid offensive language.

Avoid sending flames (abusive messages) and spam (unsolicited junk mail).





Do not use all capital letters, which is the equivalent of SHOUTING!

 Use emoticons (such as :) for smile) to express emotion.

Use abbreviations (such as BTW for by the way) for popular phrases.

 Clearly identify a spoiler, which is a message that reveals a solution to a game or an ending to a movie or program.

Read the FAQ (frequently asked questions) document.

Do not assume all material is accurate or up-to-date.

Never read someone’s private e-mail.


 The Internet






















Accessing the Internet

URLs

Searching the Web

Types of Web Pages

How Web Pages Use Multimedia

Webcasting

E-Commerce

Web Publishing

Internet Services

Netiquette

The Internet

The Internet has had a profound affect on the world of computers. Microsoft CEO Bill Gates claims,

“The Internet is pervasive in everything we’re doing.” The Internet also has assumed an increasing prominence in the world at large. Today, the letters “www” seem an omnipresent part of advertisements on buses, billboards, and magazines.

The Internet, as it is known today, was born in 1983 when ARPANET was split into two interconnected networks: ARPANET and MILNET. The size of the Internet doubled when NSFnet joined the Internet in 1986.

The Internet has proven to be a reliable means of transmitting data. Occasionally, however, transmission problems do occur. For 30 minutes in the spring of 1995, all of the traffic destined for

MIT was sent through a small wire in Florida, a situation described as equivalent to routing all of the flights bound for O’Hare to a driveway.

A c c e s s i n g t h e I n t e r n e t

National ISPs include AT&T, Earthlink, and WorldCom. Two popular OSPs are America Online

(AOL) and the Microsoft Network (MSN). Some online services supply specific types of information.

For example, Dow Jones provides financial and business news, and Imagination offers games and entertainment. WSPs include GoAmerica Communications, OmniSky, and SprintPCS. The role of

WSP is expected to grow. Industry analysts predict that by 2003, more than 60 million people will use wireless Web-enabled devices to connect to the Internet. The CEO of Amazon.com goes even farther, projecting that in 10 years all Internet connections be wireless.

Although most ISPs charge a standard fee for dial-up access, to attract users (who view advertisements on an ISP’s home page) some ISPs now are providing free service. Following this lead, a Californiabased DSL recently advertised free, high-speed Internet access (a service that usually costs $50 a month) to users who agree to ads aimed at their demographic group.

U R L s

On a Web page, a link is a built-in connection to another related Web page or part of a Web page. A link can be a word, phrase, or image. URLs make it possible to navigate using links, because each link is connected to a URL. When you click a link, the Web site or document associated with the URL is displayed. Some people refer to this activity of jumping from one Web page to another as surfing the

Web.

URLs are registered for a standard fee (usually about $70). To acquire an appropriate URL, some companies are willing to spend a great deal more for a URL that already has been registered. Recently,

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B a s i c I n f o r m a t i o n T e c h n o l o g y C o n c e p t s eCompanies paid an entrepreneur $7.5 million for a Web address. This more than doubled the previous record – Compaq’s purchase of altavista.com for $3 million.

S e a r c h i n g t h e W e b

The World Wide Web is an incredible source of information on almost any topic. There are almost 2.5 billion Web pages. Exploring this vast reservoir for the answer to a search engine user’s query, which usually is expressed in just a few keywords, is a daunting task. No wonder an engineering head at

AltaVista described search engines as a combination of “wizardry and witchcraft.”

Often, simple search queries yield an overwhelming number of results. This is attributed to several factors:

The limitations of search engines . A query about mustangs on the American plains might produce results involving Southern Methodist University's football team and the Ford car.

The nature of queries . While a traditional researcher, such as a librarian, uses queries averaging 14 words, the typical Internet query is just over one word.

The creators of Web pages . Developers of commercial Web pages sometimes distort results by repeating frequently requested keywords in the background, where spiders see them but people do not.

Despite these difficulties, search engines are among the most popular sites on the Web. When choosing a search engine, experts suggest that novice users, and users looking for obscure information, turn first to the larger search engines (AltaVista, Yahoo!, Lycos, and so on) because they are easiest to use and cast the largest net.

T y p e s o f W e b P a g e s

Advocacy Web pages established for political candidates, called “e-campaigning,” has become an important part of politics. Surveys show that more than 50 percent of Internet users turn to the Web for information about political topics.

Business/marketing Web pages used for shopping on the Internet are increasingly popular. In 1999, 17 million households shopped online. This figure is expected to grow to 49 million by 2004. A survey of back-to-school shoppers 34 years old and younger showed that 17 percent planned to shop online for their children’s school needs. Perhaps more significant, only 6 percent of surveyed shoppers reported being uncomfortable with buying on the Internet.

Educational institutions frequently publish informational Web pages. Today, most colleges have Web sites that offer course descriptions, information about the student population, and registration costs and deadlines. When shopping for college, surveys show that high school seniors use the Web more than catalogues or guidebooks; about 80 percent of college-bound students start looking at college Web sites as sophomores.

News Web pages are the most popular Web sites among Americans with access to the Internet.

Although these Web sites often are associated with newspapers, magazines, television stations, or radio stations, some are published only online, without a related print or broadcast media.

Portal Web pages often offer the following free services: search engine, news, sports and weather, free personal Web pages, reference tools, shopping malls, e-mail, instant messaging, newsgroups, and chat rooms. The dictionary defines a “portal” as a door or gateway. Portal Web pages are gateways to a host of services.

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Personal Web pages sometimes use Web cams to provide minute-by-minute views of life in a dorm room, an apartment, a new-born baby’s crib, or even the inside of a refrigerator. One devotee of these personal Web pages says visitors often develop a sort of “relationship” with the Web page developer.

Perhaps this observation is true; some personal Web pages receive more than 1,000 hits a day.

H o w W e b P a g e s U s e M u l t i m e d i a

Multimedia can bring a Web page to life, increase the types of information available on the Web, expand on the Web’s potential uses, and make the Internet a more entertaining place to explore.

Because Web pages with multimedia take longer to download, most browsers allow users to turn off some multimedia elements (such as graphics) and show a text-only version, speeding the display of a

Web page.

Choose a topic for a Web page, such as your school or your class. How could multimedia enhance the page? What multimedia elements would you use? How?

W e b c a s t i n g

Some people use Webcasting to download copyrighted material, such as music, from Web sites. Many young, unknown musicians see music Web sites as a way to gain exposure, but some already-popular musicians see sharing music on Web sites as little more than theft. The heavy metal rock band

Metallica sued Napster (a music Web site) for copyright violations. A number of colleges have placed a ban on music Web sites. These schools maintain that students downloading and sharing music creates a tremendous amount of traffic, clogging the school’s computer systems. As a result, the schools are using filtering software to deny access to music Web sites. Several student groups have formed to protest this response.

E - C o m m e r c e

Today, more than 50 percent of Web sites are commercial. Online product sales total more than $6 billion, which represents a twelve-fold increase in just five years. These numbers should be kept in perspective – in 1999, e-commerce still represented only 0.5 percent of U.S. consumer spending.

Business to consumer e-commerce often allows buyers to purchase directly from businesses, eliminating the middleman and thus providing goods and services at lower costs. Other advantages of e-commerce include:

 Twenty-four hour access

 Global presence

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

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Two-way communication

Decreased costs

Lower product display and storage costs

 Reduced salesperson costs

Businesses advertise with their own Web site or on another company’s Web site. The most successful

Web advertisements are on popular sites, such as search engines. In terms of audience, advertising on the Web is expensive. The cost to reach 1,000 consumers is about $75 on the Web, $60 in a newspaper, $44 in a magazine, and $5 on television. Yet, Web advertisements do offer advantages:

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Unlike traditional media advertising, which is passive (and often ignored by the audience), Web advertising is interactive. The audience expresses an interest in the product by clicking a hyperlink and choosing to view a Web ad.

For many products, Web users are the ideal customers. Web users tend to be students or highly educated consumers in their late 30s, with average incomes of about $55,000.

W h a t p r o d u c t s c o u l d b e n e f i t m o s t f r o m a d v e r t i s i n g o n t h e W e b .

W h y ?

W e b P u b l i s h i n g

Deciding upon the purpose of the Web site and the audience for whom it is intended will make it easier to determine what should and should not be included on the Web site. Web publishing is an increasingly commonplace Internet activity. With the assistance of word processing packages, Web page authoring software, or Web sites that assist in the creation of Web pages, even elementary school children are developing personal Web pages.

I n t e r n e t S e r v i c e s

It is estimated that the number of e-mail users has increased 300 percent during the past five years, and the number of e-mail messages sent per day has increased 400 percent. While its growth has been phenomenal, not everyone is happy with e-mail’s ever-increasing use. In a business setting, some feel that e-mail can be counter-productive. They contend that employees spend too much time writing and reading e-mail on inconsequential topics – subjects they never would commit to paper. In a social setting, some wonder if e-mail is fitting in every situation. Although e-mail is suitable for casual messages, most believe it is inappropriate for more serious or formal communication, such as a wedding invitation. How do you feel about these reservations regarding e-mail?

Many files on anonymous FTP sites are public domain software, freeware, or shareware. Public domain software is not copyrighted and therefore can be distributed at no cost. Freeware also is available at no cost but, because it is copyrighted, it cannot be resold. Shareware can be downloaded and tried for free, but a license fee must be paid if the software is kept. Shareware users who pay the license fee may receive a manual, notification of new releases or tips, and access to technical support.

The quality of freeware, public domain software, and shareware varies greatly.

The real-time character of chat makes chat rooms different from newsgroups or mailing lists. The extent to which a chat room is monitored varies. In some chat rooms, particularly those aimed at adults, a monitor’s presence hardly is noticed. Chat rooms intended for minors, however, often are monitored closely. Chat rooms can be an invaluable experience for children, letting them share thoughts and ideas with people their own age from around the country, or even around the world. Yet, to ensure that content is appropriate, parents may want to oversee a child’s first few chat room visits.

N e t i q u e t t e

Netiquette can be applied to all aspects of the Internet. Which netiquette rules are most important?

Which rules are least important? Why? What rules, if any, would you add? In her book, Guide for the

Turn-of-the-Millennium, syndicated columnist Judith Martin (Miss Manners) offers guidelines for use of the Internet and other technological innovations. Web sites such as http://www.fau.edu/netiquette/netiquette.html also offer advice on Internet manners.

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C H A P T E R 3

A P P L I C A T I O N S O F T W A R E

Overview

 Define application software

 Understand how system software interacts with application software

 Identify the role of the user interface

 Explain how to start a software application

 Identify the widely used products and explain the key features of different software applications

 Identify various products available as Web applications

 Describe the learning aids available with many software applications

This chapter discusses the role of the system software with respect to application software. It then presents an overview of several productivity software applications, graphic design/multimedia software applications, home/personal/educational software applications, and communications software applications. The chapter then identifies various Web applications. Finally, learning aids and supports tools within application software products are presented.

D e f i n e a p p l i c a t i o n s o f t w a r e

Application software consists of programs designed to perform specific tasks for users. Application software can be used as a productivity/business tool; to assist with graphics and multimedia projects; to support home, personal, and educational activities; and to facilitate communications. Specific application software products, called software packages, are available from software vendors.

Although application software also is available as shareware, freeware, and public-domain software, these usually have fewer capabilities than retail software packages.

U n d e r s t a n d h o w s y s t e m s o f t w a r e i n t e r a c t s w i t h a p p l i c a t i o n s o f t w a r e

System software consists of programs that control the operations of a computer and its devices.

System software serves as the interface between a user, the application software, and the computer’s hardware. One type of system software is the operating system. Before application software can be run, the operating system, which contains instructions that coordinate the activities among computer hardware devices, must be loaded from the hard disk into the computer’s memory.

I d e n t i f y t h e r o l e o f t h e u s e r i n t e r f a c e

The user interface controls how you enter data or instructions and how information displays on the computer screen. Many of today’s software programs have a graphical user interface. A graphical user interface (GUI) combines text, graphics, and other visual images to make software easier to use.

E x p l a i n h o w t o s t a r t a s o f t w a r e a p p l i c a t i o n

Both the Microsoft Windows and the Apple Macintosh operating systems use the concept of a desktop. The desktop is an on-screen work area with common graphical elements such as icons,

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B a s i c I n f o r m a t i o n T e c h n o l o g y C o n c e p t s buttons, menus, links, windows, and dialog boxes. A software application can be started by clicking its program name on a menu, or list of commands. Clicking the program name instructs the operating system to transfer the program’s instructions from a storage medium into memory. Once started, the application displays in a window on the desktop. A window is a rectangular area of the screen that is used to show the program, data, and/or information. At the top of the window is a title bar that contains the window’s name.

I d e n t i f y t h e w i d e l y u s e d p r o d u c t s a n d e x p l a i n t h e k e y f e a t u r e s o f

 productivity/business software applications



 graphic design/multimedia software applications home/personal/educational software applications communications software applications 

People use productivity software to become more effective and efficient while performing daily activities.



Word processing software allows users to create and manipulate documents that contain text and graphics. With word processing software, you can insert clip art into a document; change margins; find and replace text; use a spelling checker to check spelling; place a header and footer at the top and the bottom of a page; and vary font (character design), font size (character scale), and font style (character appearance).



With spreadsheet software , data is organized in rows and columns, which collectively are called a worksheet. The intersection of a row and column, called a cell, can contain a label (text), a value

(number), or a formula or function that performs calculations on the data and displays the result.



Database software allows you to create and manage a database. A database is a collection of data organized to allow access, retrieval, and use of that data. A query is used to retrieve data according to specified criteria, which are restrictions the data must meet.



Presentation graphics software is used to create presentations that communicate ideas, messages, and other information to a group through a slide show. You can use a clip gallery to enhance your presentation with clip art images, pictures, video clips, and audio clips.



A personal information manager (PIM) is software that includes an appointment calendar to schedule activities, an address book to maintain names and addresses, and a notepad to record ideas, reminders, and important information. A software suite is a collection of individual applications sold as a single package.



Project management software allows you to plan, schedule, track, and analyze the progress of a project. Accounting software helps companies record and report their financial transactions.



Power users often use software that allows them to work with graphics and multimedia.



Computer-aided design (CAD) software assists in creating engineering, architectural, and scientific designs.



Desktop publishing (DTP ) software is used to design and produce sophisticated documents. DTP is developed specifically to support page layout, which is the process of arranging text and graphics in a document.



Paint software is used to draw graphical images with various on-screen tools.



Image editing software provides the capability to modify existing images.



Video editing software and audio editing software can be used to modify video and audio segments.



Multimedia authoring software is used to create electronic interactive presentations that can include text, images, video, audio, and animation. Web page authoring software is designed to create Web pages and to organize, manage, and maintain Web sites.

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Many software applications are designed specifically for use at home or for personal or educational use.



Integrated software combines several productivity software applications that share a similar interface and common features into a single package.



Personal finance software is an accounting program that helps pay bills, balance a check book, track income and expenses, follow investments, and evaluate financial plans.



Legal software assists in the creation of legal documents and provides legal advice.



Tax preparation software guides users through the process of filing federal taxes.



Personal DTP software helps develop conventional documents by asking questions, presenting predefined layouts, and supplying standard text.



Photo-editing software is used to edit digital photographs.



A clip art/image gallery is a collection of clip art and photographs that can be used in all types of documents.



Home design/landscaping software assists with planning or remodelling.



Educational software teaches a particular skill and exists for about any subject.



Reference software provides valuable and thorough information for all individuals.



Entertainment software includes interactive games, videos, and other programs designed to support a hobby or provide amusement.

One of the main reasons people use computers is to communicate and share information.



E-mail software is used to create, send, receive, forward, store, print, and delete e-mail (electronic mail).



A Web browser is a software application used to access and view Web pages.



A chat client is software that allows you to connect to a chat room, which permits users to chat via the computer.



A newsreader is a software program used to participate in a newsgroup, which is an online area on the Web where users conduct written discussion about a particular subject.



An instant messenger is a software program installed to use instant messaging (IM), a real-time communications service that notifies you when one or more people are online and then allows you to exchange messages or files.



Groupware is a software application that helps groups of people on a network work together and share information.

A videoconference is a meeting between two or more geographically separated people who use a network or the Internet to transmit audio and video data.

I d e n t i f y v a r i o u s p r o d u c t s a v a i l a b l e a s W e b a p p l i c a t i o n s

A Web application is a software application that exists on a Web site. To access the Web application, you visit the Web site that offers the program. Some Web applications are free; for others, you pay for use, service, support, or when a certain action occurs. Web-based training (WBT) is a type of CBT

(computer-based training) that uses Internet technology. Many Web sites offer WBT to the general public. An application service provider (ASP) is a third-party organization that manages and distributes software and services on the Web.

D e s c r i b e t h e l e a r n i n g a i d s a v a i l a b l e w i t h m a n y s o f t w a r e a p p l i c a t i o n s

Many software applications and Web sites provide learning aids.

25


Online Help is the electronic equivalent of a user manual. Usually integrated into an application software package, online Help often is context-sensitive, meaning that the Help information is related to the current task being attempted. Most online Help also provide links to Web sites that have a FAQs page.

FAQs (Frequently Asked Questions) supply answers to common queries. Many books are available to help you learn to use the features of a personal computer application package.

A wizard is an automated assistant that helps complete a task by asking questions and then performing actions based on the answers.






Application software

System software

 The user interface









Starting an application

Software

Web applications

Learning aids

A p p l i c a t i o n S o f t w a r e

Popular types of application software can be categorized by their general use: productivity software, graphics design/multimedia software, home/personal/educational software, and communications software. An application can belong to more than one category. For example, an e-mail program can be considered both productivity software and communications software.

S y s t e m S o f t w a r e

Many application programs are designed to run with a specific operating system. When shopping for an application software package, buyers must make sure they have a compatible operating system. A software package designed to be used with the Macintosh operating system may not work with the

Windows operating system. The operating system version also is important. An application designed for Windows XP may not work with Windows 3.1. Yet, because most operating systems are downward compatible, software written for earlier versions of an operating system (such as Windows

98) usually can be used with recent versions of the operating system (such as Windows XP).

T h e U s e r I n t e r f a c e

The user interface plays a key role in application software. Studies have found that GUI users generally complete tasks more accurately, work faster, are more productive, and feel less fatigue than users of a text interface. The Macintosh operating system – the first popular GUI – actually was developed from an earlier GUI-based operating system created by Xerox.

The first version of Windows (1985) imitated the Macintosh’s GUI (Apple sued Microsoft, unsuccessfully, for copyright infringement). Although some users still feel the Macintosh interface is superior, today some form of Windows is used on almost 90 percent of personal computers. Because of this, even competitive products often use similar features, such as the same menu names.

S t a r t i n g a n A p p l i c a t i o n

26


To click an object on the screen, you move the pointer to the object and then press and release a button on the mouse. Often, applications also can be started by double-clicking the icon that represents the application.

When an application is started, the right-hand corner of the application window title bar usually displays three buttons:





Minimize – When clicked, this button reduces a window to a button on the taskbar.

Restore – When clicked, this button returns a window to its initial size. When a window does not

 fill the desktop, the Restore button is replaced by a Maximize button that, when clicked, enlarges the window so it covers the entire desktop.

Close – When clicked, this button closes the window. The Close button removes the window from the desktop and its button from the taskbar.

A dialog box can contain option buttons, check boxes, text boxes, and command buttons. Option buttons stipulate desired alternatives; check boxes turn specific capabilities on or off; text boxes allow text to be entered; and command buttons immediately perform an action, such as implementing (OK) or ignoring (Cancel) the choices made in a dialog box. Shortcut menus can change depending on where the pointer rests when the mouse is right-clicked. Dimmed commands on a menu or shortcut menu are unavailable.

Some applications use automatically display a smart tag when you perform a certain action. Clicking the smart tag displays a menu of commands related to the action.

S o f t w a r e

Word processing software is used for creating, editing, formatting, saving, and printing documents. In the modern office, word processing software has replaced the typewriter for almost all written work.

The editing capabilities of word processing software have altered the creative process. The freedom to express yourself without reservation, knowing you easily can revise what you have written, can improve the quality of written work. It is good practice to save a document before printing it. When a document is saved, it exists as a file, or named collection of data, instructions, or information. A file name uniquely identifies each file. Restrictions on file names once were severe; file names could be no more than eight characters long, and many characters, including spaces, could not be used. In

Windows XP, however, a file name can have up to 255 characters, including spaces.

Some spreadsheet programs offer more than 200 internal functions. When creating a spreadsheet, formulas and functions usually must be preceded by a special character (such as =, +, or @) to distinguish them from labels or values. Formulas use cell references, or addresses, of cells that contain values. When formulas are copied from one cell to another, the cell references change to reflect the new location. This update is called relative referencing. Another powerful capability, called goal-seek, finds what value is needed to reach a specified goal.

While spreadsheet packages can manage data tables of a few thousand records, database software can efficiently handle much larger data tables. In a database, common data types include text, numeric, currency, date, memo, hyperlink, and object. When identifying data types, numbers treated as text

(such as zip codes, Social Security numbers, or telephone numbers) sometimes are referred to as alphanumeric data because they are not used in calculations. The results of a database query are placed in an ANSWER table.

27


Although introduced years after word processing and spreadsheet software, presentation graphics software has had almost as great an impact on business, and on how people do business, as either of the older applications. Presentations often include an outline with the text from each slide, audience handouts that can be distributed to the audience, and a notes page with additional notes for the presenter. Some presentation graphics packages offer templates for various presentations (company meeting, financial report, marketing plan, progress report, employee orientation, training, and so on).

PIMs essentially are “free style” database managers. They are very popular with people who spend much of their time in business travel. These people, often called road warriors, find PIMs a valuable part of the arsenal they bring to their daily battles. Like a daily planner, PIMs must be reviewed regularly to be effective.

Unlike word processing software, DTP software increases hardware requirements. Because of its relatively low cost (an advanced DTP system can be purchased for less than $10,000) and the speed, control, security, and flexibility offered by desktop publishing, many companies are using DTP instead of outside printing firms for their publishing needs.

Paint software and image editing software have had a tremendous impact on commercial art.

Commercial artists praise the capabilities offered by these applications. At the same time, many feel these applications have led clients to demand more, both in terms of time and expectations. As a result, some commercial artists believe their income, actually has dropped because of graphic software.

Most software for home, personal, and educational use is relatively inexpensive. It still pays to shop around. Prices for some software for home/personal use, such as integrated software, can vary greatly for the same brand depending on the vendor. Some personal finance packages can prepare reports on income and expenses, budget, net worth, taxes, and investments.

Personal finance software wizards (automated assistants) can help to balance accounts, prepare budgets, plan mortgages, calculate savings, and arrange retirements. Legal software is designed to facilitate creation of standard documents; unusual circumstances might still demand the services of a lawyer. Tax preparation software also is best used by people in fairly common circumstances.

For some students, educational software is a welcome alternative to traditional classes, allowing them to work privately at their own pace. Reference software articles often include links that, when clicked, display related articles. Because referenced material can change frequently, some reference software packages can be updated via the World Wide Web.

Computer communications touch everyone’s life. Consider the ATM that “knows” a bank balance even though it is located 500 miles from the bank. Many e-mail programs allow users to send

“registered mail” with a return receipt guaranteeing the recipient received the message. E-mail and personal information management (PIM) software sometimes also are considered part of groupware.

Although e-mail has assumed an important role in business messages, traditional paper letters and memos still are used In fact, some maintain that the amount of paper correspondence has increased.

W e b A p p l i c a t i o n s

Web applications can be a better buy than packaged applications. For example, a $50 packaged antivirus program can be replaced by a Web application that costs less than $30 annually, is updated frequently, and uses less space on a hard disk. In addition, packaged software might include features you will never use, which increases the cost of the package. Often, you can use the standard version of a similar Web application for less money or even for free, and only pay more for the additional

28

B a s i c I n f o r m a t i o n T e c h n o l o g y C o n c e p t s features you want. Web applications can save businesses money with reduced installation, upgrade, and maintenance costs. Some social analysts believe that the lower cost of Web applications also can help close the “digital divide.”

For Web application vendors, benefits include easier updating and debugging (error correcting), removal of packaging and distribution costs, and elimination of software piracy (the illegal copying and selling of software). Despite their advantages, analysts point out that Web applications may not be right for everyone. For some consumers, paying a monthly fee ultimately costs more than the one-time purchase of packaged software. Also, many households do not have the fast Internet connection needed for certain Web applications to run smoothly. Finally, some people worry that files stored at a

Web application site can be infected with viruses. Web application vendors believe these worries are groundless and that Web applications benefit both buyers and sellers.

L e a r n i n g A i d s

In many applications, an audible “beep” indicates an error, and the last entry should be reviewed.

Function key f1 often is used to activate the Help feature. Some applications have a Help button that, when clicked, changes the mouse pointer to a Help arrow. This arrow can be used to obtain help on a command, button, or bar by pointing at the item and clicking. Many software developers have eliminated user’s manuals in favor of extensive online Help. Computer stores occasionally carry a few trade books, but entire aisles of computer-related books can be found in most large book stores.

For some applications, other learning aids, such as tutorials or keyboard templates, are available.

Tutorials are step-by-step instructions using real examples that show how to use an application.

Tutorials can be printed, software-based, or Internet-based. Keyboard templates (plastic sheets that fit around a portion of the keyboard) illustrate the keyboard commands for various tasks. Wizards can be used to help create memorandums, meeting agendas, fax cover sheets, flyers, letters, resumes, charts, forms, reports, awards, pleadings, calendars, postcards, envelopes, mailing labels, newsletters, and

Web pages. Some applications also offer document templates, which are special documents that provide basic tools for shaping a final document. The availability of learning aids and support tools is an important consideration in selecting an application package.

29


C H A P T E R 4

T H E C O M P O N E N T S O F T H E S Y S T E M U N I T

Overview

 Describe the components in the system unit

 Explain how the CPU uses the four steps of a machine cycle to process data

 Define a bit and describe how a series of bits represents data

 Differentiate between the various types of memory

 Describe the types of expansion slots and cards in the system unit

 Explain the difference between a serial, a parallel, and a USB port

 Describe how buses contribute to a computer's processing speed

 Identify components in a notebook computer

 Identify components in a handheld computer

Chapter presents the components in the system unit, described how memory stores data, instructions, and information, and discusses the sequence of operations that occur when a computer executes an instruction. The chapter included a comparison of various microprocessors on the market today.

D e s c r i b e t h e c o m p o n e n t s i n t h e s y s t e m u n i t

The system unit, sometimes called the chassis, is a box-like case housing the electronic components of a computer that are used to process data. System unit components include the processor, memory module, cards, ports, and connectors. Many of the system unit’s components reside on a circuit board called the motherboard. The motherboard contains many different types of chips, or small pieces of semiconducting material, on which one or more integrated circuits (IC) are etched. An integrated circuit is a microscopic pathway capable of carrying electronic current. Each IC can contain millions of transistors, which act as switches for electronic signals.

E x p l a i n h o w t h e C P U u s e s t h e f o u r s t e p s o f a m a c h i n e c y c l e t o p r o c e s s d a t a

The central processing unit (CPU), also called a processor, significantly impacts overall computing power and manages most of a computer’s operations. The CPU contains the control unit and the arithmetic/logic unit.

The control unit directs and coordinates most of the operations in the computer. For every instruction, the control unit repeats a set of four basic operations called the machine cycle:



 fetching the instruction or data item from memory,

 decoding the instruction into commands the computer understands,

 executing the commands, and, if necessary,

Storing, or writing the result to memory.

30


The arithmetic/logic unit (ALU) performs the execution part of the machine cycle. Specifically, the

ALU carries out three operations:

Arithmetic operations – performing calculations, which include addition, subtraction, multiplication, and division

Comparison operations – comparing data items to determine if the first item is greater than, equal to, or less than the other item

Logical operations – working with conditions and logical operators such as AND, OR, and NOT

C o m p a r e a n d c o n t r a s t v a r i o u s p e r s o n a l c o m p u t e r p r o c e s s o r s o n t h e m a r k e t t o d a y

A personal computer’s CPU usually is contained on a single chip, which some call a microprocessor.

Intel is a leading manufacturer of personal computer processors.

Most high-performance PCs use a processor from Intel called the

Pentium® processor

.

A second Intel brand, called the

Celeron™

, is designed for less expensive PCs.

Two more brands, called the Xeon™ and Itanium™ processors, are ideal for workstations and lowend servers. Intel-compatible processors have the same internal design as Intel processors and perform the same functions, but are made by other companies and often are less expensive.

An alternative design to the Intel-style processor, the Motorola processor , is found in Apple

Macintosh and Power Macintosh systems .

A new type of processor designed for lower-costing personal computers and Internet appliances, called an integrated CPU , combines functions of a processor, memory, and a video card on a single chip.

Today’s processors are equipped with MMX™ technology , a built-in set of instructions that manipulates and processes multimedia data more efficiently.

Intel’s SSE instructions

and

AMD’s

3DNow!™

are two other technologies that improve a processor’s performance of multimedia, the

Web, and 3-D graphics. To optimize and extend battery life for notebook computers, Intel® mobile processors use

SpeedStep™

technology and AMD processors use

PowerNow!™

technology.

D e f i n e a b i t a n d d e s c r i b e h o w a s e r i e s o f b i t s r e p r e s e n t s d a t a

Most computers are digital, meaning they understand only two discrete states: on and off. These states are represented using two digits, 0 (off) and 1 (on). Each on or off value is called a bit (short for binary digit), the smallest unit of data a computer can handle. Eight bits grouped together as a unit form a byte. A byte provides enough different combinations of 0s and 1s to represent 256 individual characters including numbers, letters of the alphabet, punctuation marks, and other characters.

The combinations of 0s and 1s used to represent data are defined by patterns called coding schemes.

Popular coding schemes are ASCII, EBCDIC, and Unicode. Coding schemes make it possible for humans to interact with a digital computer that recognizes only bits. Every character you type on a keyboard is converted into a corresponding byte, a series of on/off electrical states the computer can process.

D i f f e r e n t i a t e b e t w e e n t h e v a r i o u s t y p e s o f m e m o r y

31


Memory is a temporary storage place for data, instructions, and information. Memory stores the operating system, application programs, and the data processed by application programs. A byte is the basic storage unit in memory. Memory size is measured by the number of bytes available for use.



A kilobyte (KB or K) of memory is approximately one thousand bytes,

 a megabyte (MB) is approximately one million bytes, and

 a gigabyte (GB) is approximately one billion bytes.

T h e s y s t e m u n i t c o n t a i n s s e v e r a l t y p e s o f m e m o r y .

RAM (random access memory) consists of memory chips that the processor can read from and write to. Most RAM is volatile memory, meaning that its contents are lost when the computer’s power is turned off. Two basic types of RAM chips are dynamic RAM and static RAM.

Dynamic RAM (DRAM) must be re-energized constantly or it loses its contents.

Static RAM (SRAM) is faster and more reliable than DRAM and has to be re-energized less often, but it is much more expensive.

Memory cache, also called a cache store or RAM cache, improves processing time by storing frequently used instructions and data.

ROM (read-only memory) refers to memory chips that only can be read and used; that is, they cannot be modified. ROM is non-volatile memory (NVM), meaning that its contents are not lost when the computer’s power is turned off. A variation of the ROM chip, called programmable read-only memory

(PROM), is a blank chip on which you can place items permanently.

Flash memory, also known as flash ROM or flash RAM, is non-volatile memory that can be erased electronically and reprogrammed.

Complementary metal-oxide semiconductor (CMOS) memory, another type of memory chip, stores configuration information about the computer and uses battery power to retain information when the power to the computer is off.

D e s c r i b e t h e t y p e s o f e x p a n s i o n s l o t s a n d c a r d s i n t h e s y s t e m u n i t

An expansion slot is an opening, or socket, where you can insert a circuit board into the motherboard.

These circuit boards – called cards, expansion cards, boards, expansion boards, adapters, adapter cards, interface cards, add-ins, or add-ons -- add new devices or capabilities to the computer. Four types of expansion cards found in most computers are a video card , a sound card , a network interface card , and a modem card .

A video card converts computer output into a video signal that is sent through a cable to the monitor, which displays an image.

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

32


A network interface card (NIC) is a communications device that allows the computer to communicate via a network.

A modem card is a communications device that enables computers to communicate via telephone lines or other means. Many of today’s computers support Plug and Play, a capability with which the computer automatically can configure expansion boards and other devices as you install them.

Notebook and other portable computers have a special type of expansion slot used for installing a PC

Card, which is a thin credit card-sized device that adds memory, disk drives, sound, fax/modem, and communications capabilities to a mobile computer.

E x p l a i n t h e d i f f e r e n c e b e t w e e n a s e r i a l , a p a r a l l e l , a n d a U S B p o r t

A cable often attaches external devices to the system unit. A port is the interface, or point of attachment, to the system unit. Ports have different types of connectors, which are used to join a cable to a device. Male connectors have one or more exposed pins, while female connectors have matching holes to accept the pins.

Most computers have three types of ports : serial, parallel , and USB .

A serial port is a type of interface that connects a device to the system unit by transmitting data only one bit at a time. Serial ports usually connect devices that do not require fast data transmission rates, such as a mouse, keyboard, or modem.

A parallel port is an interface that connects devices by transferring more than one bit at a time. Many printers connect to the system unit using a parallel port.

A universal serial bus (USB) port can connect up to 127 different peripheral devices with a single connector type, greatly simplifying the process of attaching devices to a personal computer.

D e s c r i b e h o w b u s e s c o n t r i b u t e t o a c o m p u t e r ' s p r o c e s s i n g s p e e d

Bits are transferred internally within the circuitry of the computer along electrical channels. Each channel, called a bus, allows various devices inside and attached to the system unit to communicate with each other.

The bus width, or size of the bus, determines the number of bits that can be transferred at one time.

The larger the bus width, the fewer number of transfer steps required and the faster the transfer of data.

In most computers word size (the number of bits the CPU can process at a given time) is the same as the bus width.

Every bus also has a clock speed. The higher the bus clock speed, the faster the transmission of data, which results in applications running faster.

A computer has two basic types of buses.

33


A system bus connects the CPU to main memory.

An expansion bus allows the CPU to communicate with peripheral devices.

I d e n t i f y c o m p o n e n t s i n a n o t e b o o k c o m p u t e r

Users with mobile computing needs often have a mobile computer, such as a notebook computer and/or handheld computer. A notebook computer, also called a laptop computer, can run either using batteries or using a standard power supply. In addition to the motherboard, processor, memory, sound card, PC Card slot, and drive bay, the system unit for a notebook computer also houses other devices, such as the keyboard, pointing device, speakers, and display.

I d e n t i f y c o m p o n e n t s i n a h a n d h e l d c o m p u t e r

Handheld computers run strictly on battery. Similar to desktop and notebook computers, handheld computers have a system unit that contains electronic components that process data. A handheld computer’s system unit also contains a display and may house speakers and some form of keyboard and/or pointing device. Handheld computers often have an IrDA port so you can communicate wirelessly with other computers. Many also include a serial port.






The system unit

The CPU

 Processor comparison















Data representation

Memory

Expansion slots and expansion cards

Ports

Buses

Notebook computers

Handheld computers

T h e S y s t e m U n i t

The motherboard in the system unit contains different types of chips. Manufacturers package chips so the chips can be attached to circuit boards, such as the motherboard.

Types of chip packages include:

Dual inline package (DIP ), which consists of two parallel rows of downward-pointing thin metal feet

(pins)

Pin grid array (PGA) package , which holds a larger number of pins because the pins are mounted on the surface of the package

Flip chip-PGA (FC-PGA) package, which places chips on the opposite side (flip side) of the pins

Single edge contact (SEC) cartridge , which connects to the motherboard on one of its edges

T h e C P U

34


The power of personal computer processor chips (the chips that contain the CPU) has grown at an astounding rate. As chips become older and more widely used, price cuts usually are introduced.

Several factors affect CPU processing speed. CPUs in most of today’s personal computers use pipelining , a technique that increases processing speed by beginning execution of a second machine cycle instruction before the first instruction is completed. CPUs also use high-speed storage locations, called registers, to hold data and instructions temporarily. The control unit relies on a small chip called the system clock to synchronize all computer operations. The speed at which a processor executes instructions is called clock speed, or clock rate, and is measured in megahertz (MHz). The system clock is a major factor affecting processor speed. A higher clock speed means the CPU can process more instructions per second.

P r o c e s s o r C o m p a r i s o n

Although once frequently used, the term “microprocessor” is much less common today.

Sometimes you can upgrade your processor to increase the computer’s performance. There are three forms of upgrades:



With a chip for chip upgrade, the existing processor chip is replaced with a new one



With a piggyback upgrade, the new processor is stacked on top of the old one



With a daughterboard upgrade, the new processor is on a small circuit board (the daughterboard) that plugs into the motherboard

The past three years have seen a steady drop in the cost of computers. PC prices plunged as a result of lower prices for processors, memory chips, and hard drives. Consumers also are showing increased interest in new less powerful, but less expensive, personal computers that work perfectly well for the most popular uses – word processing, Internet access, and spreadsheet applications. The surge in lowpriced computer sales has had an impact on Intel, the world’s largest processor manufacturer. By focusing on making inexpensive processor chips, rivals AMD and Cyrix are making inroads into

Intel’s dominance. Intel’s response, the Celeron™, has proven popular, but the lower-priced chip offers a smaller profit margin.

D a t a R e p r e s e n t a t i o n

Just as the decimal system (10 digits) is suited to human anatomy (10 fingers), the binary system (2 digits) is perfect to represent the on-off states (2 states) of a computer. Basic coding standards make it possible for components within computers to communicate, allow manufacturers to be confident that the components they produce will operate correctly in a computer, and enable consumers to purchase components that are compatible with their systems. In the ASCII-8 and EBCDIC codes, the first four characters represent the zone, and the last four characters represent the digits 1 through 8. ASCII, originally a seven-bit code, was expanded to eight bits in an effort to provide for symbols used in other nations. Unicode, a 2-byte (16-bit) code, can represent 216, or 65,536, characters. The system employs the codes used by ASCII and also includes other alphabets (such as Cyrillic and Hebrew), special characters (including religious symbols), and some of the “word writing” symbols used by various

Asian countries.

M e m o r y

35


Because computers use the binary number system, the actual values for the units in which memory and storage are measured are based on powers of 2. For example, one kilobyte = 210 = 1,024.

RAM’s volatility, and its ability to be changed, are its most distinguishing characteristics. When RAM is purchased it comes in banks of nine chips – eight are needed to represent a byte and the ninth is needed for parity. RAM chips usually are packaged on small circuit boards called single inline memory modules (SIMMs) or dual inline memory modules (DIMMs) that are inserted into the motherboard. During the past 20 years, the price of RAM has dropped an average of 20 percent each year, but its capacity has more than doubled every two years.

Similar to flash ROM, another variation of ROM, called EEPROM (electrically erasable programmable read-only memory), can be erased electrically and rewritten. Because of its non-volatile nature, EEPROM is used in electronic cash registers to store item prices.

The amount of time it takes the processor to read data from memory, called access time , directly affects how fast the computer can process data. Memory access time is measured in terms of nanoseconds, or billionths of a second.

36


C H A P T E R 5

I N P U T

Overview

 Describe the two types of input

 List the characteristics of a keyboard

 Identify various types of keyboards

 Identify various types of pointing devices

 Explain how a mouse works

 Describe different mouse types

 Explain how voice recognition works

 Understand how to input data into a handheld computer

 Identify the uses of a digital camera

 Describe the various techniques used for video input

 Describe the uses of PC video cameras and web cams

 Explain how scanners and other reading devices work

 Identify alternative input devices for physically challenged users

In this chapter, you learn what input is and what input devices are. The keyboard is presented and different keyboard types are described. You are introduced to various pointing devices, such as the mouse, trackball, touchpad, pointing stick, joystick, touch screen, and pen input. Scanners and reading devices, including optical scanners, optical readers, magnetic ink character recognition readers, and data collection devices are explained. You learn about digital cameras, audio input, speech recognition, video input, and videoconferencing. Finally, input devices for physically challenged users are explored.

D e s c r i b e t h e t w o t y p e s o f i n p u t

Input is any data or instructions entered into the memory of a computer. Two types of input are data and instructions.

Data is a collection of unorganized items that can include words, numbers, pictures, sounds, and video.

A computer processes data into information, which is organized, meaningful, and useful.

Instructions can be in the form of programs, commands, or user responses.

A program is a series of instructions that tells a computer how to perform the tasks necessary to process data into information.

A command is an instruction given to a computer program.

37


A user response is an instruction you issue to the computer by responding to a question posed by a computer program.

Any hardware component that allows you to enter data, programs, commands, and user responses into a computer is an input device .

L i s t t h e c h a r a c t e r i s t i c s o f a k e y b o a r d

The keyboard is an input device that contains keys you press to enter data into a computer. Desktop computer keyboards usually have from 101 to 105 keys, while keyboards for smaller computers contain fewer keys.

All keyboards have a typing area used to type letters of the alphabet, numbers, punctuation marks, and other basic characters.

Many desktop computer keyboards also have

 a numeric keypad designed to make it easier to enter numbers,

 function keys programmed to issue commands and accomplish certain tasks,

 arrow keys used to move the insertion point (a symbol on the screen that indicates where the next typed character will display), and



Toggle keys that can be switched between two different states.

I d e n t i f y v a r i o u s t y p e s o f k e y b o a r d s

A standard computer keyboard sometimes is called a QWERTY keyboard because of the layout of its typing area.

An enhanced keyboard has 12 function keys along the top row, 2 ctrl keys, 2 alt keys, and a set of arrow and additional keys between the typing area and the numeric keypad.

Cordless keyboards transmit data via infrared light waves.

Keyboards for notebook and handheld computers usually have smaller and fewer keys than desktop computers.

A portable keyboard is a full-sized keyboard you can attach to and remove from a handheld computer.

Some manufacturers have designed ergonomic keyboards to reduce the chance of workplace injuries.

The goal of ergonomics is to incorporate comfort, efficiency, and safety into the design of workplace items.

I d e n t i f y v a r i o u s t y p e s o f p o i n t i n g d e v i c e s

In a graphical user interface, the pointer is a small symbol on the screen. A pointing device is an input device that allows you to control the pointer. Common pointing devices include the mouse, trackball, touchpad, pointing stick, joystick, touch screen, light pen, and a stylus.



A mouse is a pointing device, designed to fit comfortably under the palm of your hand, that is moved across a flat surface.



A trackball is a stationary pointing device with a ball mechanism on its top.

38




A touchpad is a flat, rectangular pointing device that is sensitive to pressure and motion.



A pointing-stick is a pressure-sensitive pointing device shaped like a pencil eraser that is positioned between keys on the keyboard.



A joystick is a vertical lever mounted on a base.



A light pen is a handheld device that contains a light source or can detect light.



A touch screen is a touch-sensitive display on the screen.



A stylus looks like a ballpoint pen but uses pressure, instead of ink, to write text and draw lines.



An electronic pen can be used on a graphics tablet, which consists of a flat, rectangular, electronic plastic board used to input graphical data.

E x p l a i n h o w a m o u s e w o r k s

As you move a mouse across a flat surface, the movement is translated into signals that are sent to the computer, and the pointer on the screen also moves. When you move the mouse to the right, the pointer moves to the right on the screen. For Windows users, the top of a mouse has at least two buttons and sometimes also a wheel. Generally, you use a mouse to move the pointer on the screen to an object and then press a button, or click, to perform a certain action on that object. Other operations you can perform using a mouse include right-click, double-click, drag, right-drag, rotate wheel, and press wheel button.

D e s c r i b e d i f f e r e n t m o u s e t y p e s

A mechanical mouse has a rubber or metal ball on its underside. When the ball rolls in a certain direction, electronic circuits in the mouse translate the movement into signals that are sent to the computer. For better traction, you should place a mechanical mouse on a mouse pad.

An optical mouse has no moving parts; instead it uses devices that emit and sense light to detect the mouse’s movement. An optical mouse can be used on nearly all surfaces, is more precise than a mechanical mouse, and does not require cleaning.

A cordless mouse, or wireless mouse, is a battery powered device that transmits data using wireless technology, such as radio waves or infrared light waves. A cordless mouse uses technology very similar to that of a cordless keyboard.

E x p l a i n h o w v o i c e r e c o g n i t i o n w o r k s

Voice input is the process of entering data by speaking into a microphone that is attached to the sound card on a computer. Voice recognition is the computer’s capability of distinguishing spoken words.

The first voice recognition programs were speaker dependent. With speaker-dependent software, the computer makes a profile of your voice, which means you have to train the computer to recognize your voice. Today, most voice recognition programs use speaker-independent software, which has a built-in set of word patterns and does not have to be trained to recognize your voice. Some voice recognition software requires discrete speech, meaning that you have to speak slowly and separate each word with a short pause. Most voice recognition products, however, support continuous speech, allowing you to speak in a flowing conversational tone.

U n d e r s t a n d h o w t o i n p u t d a t a i n t o a h a n d h e l d c o m p u t e r

To satisfy the input needs of many different types of users, handheld computers provide many different ways to input data. A handheld computer typically includes a basic stylus. With the stylus,

39

B a s i c I n f o r m a t i o n T e c h n o l o g y C o n c e p t s you can enter data using an on-screen keyboard or using handwriting recognition software that translates handwritten letters and characters into symbols the computer understands. Other input alternatives available with some handheld computers include attaching a full-sized keyboard, transferring data from a desktop computer, using voice input, and attaching a digital camera.

I d e n t i f y t h e u s e s o f a d i g i t a l c a m e r a

A digital camera is used to take pictures and store the photographed images digitally instead of on traditional film. Pictures are stored on a storage medium, such as a floppy disk, SuperDisk, Clik! disk,

PC Card, compact flash card, memory stick, mini-CD, or microdrive. Many digital cameras allow you to review and edit the images while they are in the camera. You also can download, or transfer a copy of, the stored image to a computer. Once on a computer, the pictures can be edited with photo-editing software, printed, faxed, sent via electronic mail, included in another document, or posted to a Web site.

There are three basic types of digital cameras.

A studio camera is a stationary digital camera used for professional studio work.

A field camera is a portable camera, often used by photojournalists, that has many lenses and other attachments.

A point-and-shoot camera is more affordable and lightweight and provides acceptable quality photographic images for the home or small business user.

D e s c r i b e t h e v a r i o u s t e c h n i q u e s u s e d f o r v i d e o i n p u t

Video input, or video capture, is the process of entering a full-motion recording into a computer and storing the video on a storage medium.

Many video devices use analogue video signals. To input video from these devices, the device is plugged into a video capture card, an expansion card that converts the analogue signal into a digital signal the computer can understand.

A digital video (DV) camera is a new generation of video camera that records video as digital signals, instead of using analogue signals, and therefore does not require a video capture card. Video files can demand huge amounts of storage space.

Video compression reduces the size of video files by recognizing that only a small portion of an image changes from frame to frame. Instead of storing every frame in its entirety, a video compression program might store an initial frame and then store only the changes from one frame to the next.

A video decoder is a card that decompresses video. A video digitizer can be used to capture an individual frame from a video and save the still picture in a file.

D e s c r i b e t h e u s e s o f P C v i d e o c a m e r a s a n d W e b c a m s

40


A PC camera is a DV camera that allows home users to record, edit, capture video and still images, and make video telephone calls on the Internet. During a video telephone call, both parties can see each other as they talk. Although usually placed on top of the monitor and attached to a computer’s

USB port, some PC cameras are portable and can be used anywhere.

41


C H A P T E R 6

O U T P U T

Overview

 Define the four categories of output

 Identify the different types of display devices

 Describe factors that affect the quality of a display device

 Identify monitor ergonomic issues

 Explain the differences among various types of printers

 Describe the uses of speakers and headsets

 Identify the purpose of data projectors, fax machines, and multifunction devices

 Explain how a terminal is both an input and output device

 Identify output options for physically challenged users

In this chapter, you learn what is output and what are output devices. Display devices are introduced, including CRT monitors, flat-panel displays, video cards, and high-definition television. You explore monitor quality and monitor ergonomics. Various types of printers are presented, such as impact printers, non-impact printers, portable printers, plotters and large-format printers, and special-purpose printers. You find out about audio output and other output devices, including data projectors, facsimile machines, and multifunction devices. Finally, you become acquainted with terminals and output devices for physically challenged users.

D e f i n e t h e f o u r c a t e g o r i e s o f o u t p u t

Output is data that has been processed into a useful form called information. Four types of output are text, graphics, audio, and video.

Text consists of characters (letters, numbers, punctuation marks, or any other symbol requiring one byte of computer storage space) that are used to create words, sentences, and paragraphs.

Graphics are digital representations of non-text information such as drawings, charts, photographs, and animation (a series of still images in rapid sequence that gives the illusion of motion).

Audio is music, speech, or any other sound.

Video consists of images played back at speeds to provide the appearance of full motion.

An output device is any computer component capable of conveying information to a user.

I d e n t i f y t h e d i f f e r e n t t y p e s o f d i s p l a y d e v i c e s

A display device is an output device that visually conveys text, graphics, and video information.

Information shown on a display device is called soft copy because the information exists electronically and is displayed for a temporary period of time. Display devices include CRT monitors, LCD monitors and displays, gas plasma monitors, and televisions.

42


A CRT monitor is a monitor that is similar to a standard television set because it contains a cathode ray tube. A cathode ray tube (CRT) is a large, sealed, glass tube. The front of the tube is a screen coated with phosphor material that glows as an electron beam moves back and forth, which produces an image on the screen.

LCD monitors and LCD displays use liquid crystal to present information on the screen. A liquid crystal display (LCD) has liquid crystals between two sheets of material. When an electric current passes through the crystals, they twist, causing some light waves to be blocked and allowing others to pass through, which creates the images.

Similar to an LCD display, a gas plasma monitor is a flat-panel display. A gas plasma monitor, however, substitutes a layer of gas for the liquid crystal material. When voltage is applied, the gas releases ultraviolet light that causes pixels on the screen to glow and form an image.

An NTSC converter converts a computer’s digital signal into an analogue signal that a standard television set can display. High-definition television (HDTV) is a type of television set that works with digital broadcasting signals and supports a wider screen and higher resolution than a standard television set.

D e s c r i b e f a c t o r s t h a t a f f e c t t h e q u a l i t y o f a d i s p l a y d e v i c e

The quality of a CRT monitor depends largely on its resolution, dot pitch, and refresh rate. The quality of an LCD monitor or display depends primarily on its resolution.

A CRT monitor’s screen is coated with tiny dots of phosphor material, called pixels, that glow when electrically charged to produce an image.

Resolution , which describes the sharpness and clearness of that image, is related directly to the number of pixels a monitor can display. The greater the number of pixels the display uses, the better the quality of the image.

Dot pitch , a measure of image clarity, is the distance between each pixel on a display. The smaller the distance between pixels (dot pitch), the sharper the image.

Refresh rate is the speed that a monitor redraws images on the screen. Refresh rate should be fast enough to maintain a constant, flicker-free image.

The resolution of an LCD monitor or display generally is proportional to the size of the monitor or display. That is, the resolution increases for larger monitors and devices.

I d e n t i f y m o n i t o r e r g o n o m i c i s s u e s

The goal of ergonomics is to incorporate comfort, efficiency, and safety into the design of items in the workplace. Features that address monitor ergonomic issues include controls to adjust the brightness, contrast, positioning, and height and width of images. Newer monitors have digital controls that allow you to fine-tune the display. Many monitors also have a tilt and swivel base so the angle of the screen can be altered to minimize neck strain and glare. Monitors produce a small amount of electromagnetic radiation (EMR), which is a magnetic field that travels at the speed of light. High-quality monitors should comply with MPR II, a standard that defines acceptable levels of EMR for a monitor.

43


E x p l a i n t h e d i f f e r e n c e s a m o n g v a r i o u s t y p e s o f p r i n t e r s

A printer is an output device that produces text and graphics on a physical medium such as paper or transparency film. Printed information is called hard copy because the information exists physically and is a more permanent from of output. Printers can be grouped in two categories: impact and nonimpact.

Impact printers form characters and graphics by striking a mechanism against an ink ribbon that physically contacts the paper.

A dot-matrix printer is an impact printer that prints images when tiny wire pins on a print head mechanism strike an inked ribbon.

A line printer is an impact printer that prints an entire line at one time. Two popular types of line printers are band printers and shuttle-matrix printers.

Non-impact printers form characters and graphics without actually striking the paper.

An ink-jet printer is a non-impact printer that sprays drops of ink onto a piece of paper.

A laser printer is a non-impact printer that creates images using a laser beam and powdered ink, called toner.

A thermal printer is a non-impact printer that generates images by pushing electrically heated pins against heat-sensitive paper. Although the print quality of standard thermal printers generally is low, two special types of thermal printers, thermal wax-transfer printers and dye-sublimation printers, have a much higher print quality.

Some printers are used for special purposes.

A photo printer is a colour printer that can produce photo lab quality pictures as well as printing everyday documents.

A label printer is a small printer that prints on an adhesive type material that can be placed on a variety of items.

A portable printer is a small, lightweight printer that allows a mobile user to print from a notebook or handheld computer while travelling.

Plotters are sophisticated printers used to produce high-quality drawings such as blueprints, maps, and circuit diagrams.

A large-format printer , which operates like an ink-jet printer but on a larger scale, creates photorealistic quality colour prints.

D e s c r i b e t h e u s e s o f s p e a k e r s a n d h e a d s e t s

An audio output device produces music, speech, or other sounds. Two commonly used audio output devices are speakers and headsets.

44


Most personal computers have an internal speaker that outputs low-quality sound. Many users add high-quality stereo speakers or purchase PCs with larger speakers built into the sides of the monitor. A woofer can be added to boost low bass sounds.

A headset plugged into a port on the sound card allows only the user to hear sound from the computer.

I d e n t i f y t h e p u r p o s e o f d a t a p r o j e c t o r s , f a x m a c h i n e s , a n d m u l t i f u n c t i o n d e v i c e s

A data projector takes the image on a computer screen and projects it onto a large screen so that an audience of people can see the image. Two smaller, lower priced data projectors are an LCD projector, which uses liquid crystal display technology, and a digital light processing (DLP) projector, which uses tiny mirrors.

A facsimile (fax) machine transmits and receives documents over telephone lines. A fax modem is a communication device that allows you to send (and sometimes receive) electronic documents as faxes.

A multifunction device (MFD) is a single piece of equipment that looks like a copy machine but provides the functionality of a printer, scanner, copy machine, and sometimes a fax machine.

CHAPTER 7

S T O R A G E

Overview

 Differentiate between storage and memory

 Identify various types of storage media and storage devices

 Explain how a floppy disk stores data

 Identify the advantages of using high-capacity disks

 Describe how a hard disk organizes data

 Identify the advantages of using an Internet hard drive

 Explain how a compact disc stores data

 Understand how to care for a compact disc

 Differentiate between CD-ROMs, CD-RWs, and DVD-ROMs

 Identify the uses of tape

 Understand how an enterprise storage system works

 Explain how to use PC cards and other miniature storage media

 Identify uses of microfilm and microfiche

45


This chapter explains various storage media and storage devices. Students discover how memory is different from storage. Floppy disks are introduced, and characteristics of a floppy disk, floppy disk drives, care of floppy disks, and high-capacity floppy disks are presented. Hard disks are explained, and students find out about characteristics of a hard disk, how a hard disk works, removable hard disks, hard disk controllers, RAID, and maintaining data on a hard disk. Compact discs, including CD-

ROMs and DVD-ROMs, are described. Finally, students learn about tapes, PC Cards, and other types of storage such as smart cards, microfilm and microfiche.

D i f f e r e n t i a t e b e t w e e n s t o r a g e a n d m e m o r y

Memory, which is composed of one or more chips on the motherboard, is a temporary holding place for data and instructions during processing. The contents of volatile memory, such as RAM, are lost when the power to the computer is turned off. The contents of nonvolatile memory, such as ROM, are not lost when power is removed from the computer.

Storage holds items such as data, instructions, and information for future use; that is, storage holds these items while they are not being processed. Storage is nonvolatile, which means the items in storage are retained even when power is removed from the computer. Compared to memory, the access time (the time it takes to locate a single item) for storage is slow.

I d e n t i f y v a r i o u s t y p e s o f s t o r a g e m e d i a a n d s t o r a g e d e v i c e s

A storage medium (media is the plural) is the physical material on which items are kept. A storage device is the computer hardware that records and retrieves items to and from a storage medium.

Storage devices can function as sources of input and output.

When storage devices transfer items from a storage medium into memory – a process called reading – they function as sources of input.

When storage devices transfer items from memory to a storage medium – a process called writing – they function as sources of output.

Types of storage media include floppy disks, hard disks, compact discs, tape, PC Cards, microfilm, and microfiche.

E x p l a i n h o w a f l o p p y d i s k s t o r e s d a t a

A floppy disk is a portable, inexpensive storage medium that consists of a thin, circular, flexible plastic disk with a magnetic coating enclosed in a square-shaped plastic shell. A floppy disk drive

(FDD) is a device that can read from and write on a floppy disk. When you insert a floppy disk into a floppy disk drive, a shutter on the disk’s plastic shell slides to the side to expose the disk’s recording surface. A floppy disk is a type of magnetic media because it uses magnetic patterns to store items.

Data is stored in tracks and sectors. A track is a narrow recording band that forms a full circle on the surface of the disk. The disk’s storage locations consist of pie-shaped sections, which break the track into small arcs called sectors. For reading and writing purposes, sectors are grouped into clusters. A

46

B a s i c I n f o r m a t i o n T e c h n o l o g y C o n c e p t s cluster consists of two to eight sectors and is the smallest unit of space used to store data. Formatting is the process of preparing a disk for reading and writing.

I d e n t i f y t h e a d v a n t a g e s o f u s i n g h i g h - c a p a c i t y d i s k s

A high-capacity disk drive is a disk drive that uses disks with capacities of 100 MB and greater

(remember, a typical floppy disk can store only up to 1.44 MB). High-capacity disks are used to store large graphics, audio, or video files and for backup. A backup is a duplicate of a file, program, or disk that can be used if the original is lost, damaged, or destroyed.

Three high-capacity disk drives are the SuperDisk™ drive, the

HiFD™ drive

, and the

Zip® drive

.

The SuperDisk™ drive reads from and writes on a 120 MB or 250 MB SuperDisk™.

The

HiFD™

(High-Capacity FD) drive reads from and writes on a 200 MB HiFD™ disk.

The Zip® drive is a high-capacity disk drive that uses a Zip® disk. The Zip® disk is larger and thicker than a 3.5-inch floppy disk and can store 100 MB or 250 MB of data.

D e s c r i b e h o w a h a r d d i s k o r g a n i z e s d a t a

A hard disk, or hard disk drive, consists of several inflexible, circular platters that store items electronically. A platter in a hard disk is made of aluminium, glass, or ceramic and is coated with a material that allows items to be recorded magnetically on its surface. Each platter has two read/write heads, one for each side. Because of the stacked arrangement of the platters, the location of the read/write heads often is referred to by its cylinder, which is the location of a single track through all platters. Some computers improve hard disk access time by using a disk cache, which is a portion of memory that the processor uses to store frequently accessed items. A hard disk can be divided into separate areas, called partitions, each of which functions as if it were a separate hard disk drive.

I d e n t i f y t h e a d v a n t a g e s o f u s i n g a n I n t e r n e t h a r d d r i v e

An Internet hard drive is a service on the Web that provides storage to computer users. People use

Internet hard drives to:

Eliminate the need to transport files when away from a desktop computer

Instantaneously save large audio, video, and graphics files when surfing the Web

Make audio files, video clips, or pictures available to family, friends, co-workers, and customers

Immediately view time-critical data and images while away from a main office or location

Store offsite backups of data

47


E x p l a i n h o w a c o m p a c t d i s c s t o r e s d a t a

A compact disc (CD) is a flat, round, portable metal storage medium that usually is 4.75 inches in diameter and less than one-twentieth of an inch thick. Compact discs store items using microscopic pits (indentations) and land (flat areas) that are in the middle layer of the disc. A high-powered laser light creates the pits in a single track, divided into evenly spaced sectors, that spirals from the centre to the edge of the disc. A low-powered laser reads items by reflecting light off the disc surface. The reflected light is converted into a series of bits that the computer can process.

U n d e r s t a n d h o w t o c a r e f o r a c o m p a c t d i s c

With proper care, a compact disc is guaranteed to last five years, but could last up to 50 years.

Compact discs should not be stacked or exposed to excessive heat, cold, sunlight, or contaminants. A compact disc should be held by its edges (do not touch the underside of the disc) and placed in its protective case, called a jewel box, when it is not being used. You can clean the bottom surface with a soft cloth and warm water or a specialized CD cleaning kit, and you can repair scratches on the bottom surface with a specialized compact disc repair kit.

D i f f e r e n t i a t e b e t w e e n C D - R O M s , C D - R W s , a n d D V D - R O M s

A CD-ROM, or compact disc read-only memory, is a compact disc that uses the same laser technology as audio CDs. For a computer to read items stored on a CD-ROM, you insert the disc into a CD-ROM drive or CD-ROM player. When viewing animation or video, the speed of a CD-ROM drive, or data transfer rate, is important. A higher the data transfer rate, results in smoother playback of images and sounds.

Most standard CDs are single-session because manufacturers record (write) all items to the disc at one time. Variations of standard CD-ROMs, such as PhotoCD, CD-R (compact disc-recordable), and CD-

RW (compact disc-rewritable), are multisession, which means additional data, instructions, and information can be written at a later time.

A PhotoCD is a compact disc that contains digital photographic images.

A CD-R (compact disc-recordable ) is a multisession compact disc onto which you can record your own items.

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

A DVD-ROM (digital video disc-ROM ) is an extremely high-capacity compact disc capable of storing from 4.7 GB to 17 GB. In order to read a DVD-ROM, you must have a DVD-ROM drive. You also can obtain recordable and rewritable versions of DVD.

A DVD-R (DVD-recordable ) allows you to write on it once and read (play) it many times.

With the new rewritable DVD, called a DVD+RW , you can erase and record on the disc multiple times.

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I d e n t i f y t h e u s e s o f t a p e

Tape, one of the first storage media used with mainframe computers, is a magnetically-coated ribbon of plastic capable of storing large amounts of data and information at low cost. Because it requires sequential access, or consecutive reading and writing of data, tape is used for long-term storage and backup. (Floppy disks, hard disks, and compact discs all use direct access, which means you can locate a data item immediately, without having to move through all the items stored in front of it.)

U n d e r s t a n d h o w a n e n t e r p r i s e s t o r a g e s y s t e m w o r k s

An enterprise storage system is a strategy that focuses on the availability, protection, organization, and backup of storage in a company. To implement an enterprise storage system, a company uses a combination of techniques.



A server stores items needed by users on a network. A RAID system ensures that data is not lost.



A tape library is a high-capacity tape system that works with multiple tape cartridges for storing backups of data, information, and instructions.



A CD-ROM jukebox holds hundreds of CD-ROMs that can contain application programs and data.



An Internet backup can store data, information, and instructions on the Web.



A network attached storage (NAC) is an easy way to add hard disk space to a network.



A storage area network (SAN) is a high-speed network that connects storage devices.

E x p l a i n h o w t o u s e P C C a r d s a n d o t h e r m i n i a t u r e s t o r a g e m e d i a

A PC Card is a thin, credit card-sized device that fits into a PC Card slot on a notebook or personal computer. PC Cards are used to add storage, memory, communications, and sound capabilities.

A smart card stores data on a thin microprocessor embedded in a card similar in size to an ATM card.

Two types of smart cards exist: intelligent and memory.

An intelligent smart card contains a processor and has input, process, output, and storage capabilities.

A memory card has only storage capabilities.

I d e n t i f y u s e s o f m i c r o f i l m a n d m i c r o f i c h e

Microfilm and microfiche store microscopic images of documents on roll or sheet film. Microfilm uses a 100- to 215-foot roll of film. Microfiche uses a small sheet of film, usually about four inches by six inches. Libraries and large organizations use microfilm and microfiche to archive relatively inactive documents and files.

49



 Memory vs. storage

 Storage media and devices























Floppy disks

High-capacity disks

Hard disks

Advantages of an Internet Hard Drive

Compact discs

Caring for compact discs

CD-ROMs, CD-RWs, and DVD-ROM

Tape

Enterprise storage systems

PC cards and miniature storage media

Microfilm and microfiche

M e m o r y v s . S t o r a g e

In general, memory (RAM) is fast, short-term, and volatile. Storage, on the other hand, is slower, longterm, and non-volatile. Like non-volatile memory, the contents of storage are retained when a computer’s power is turned off. Unlike most non-volatile memory, however, the contents of storage usually can be erased or changed.

S t o r a g e M e d i a a n d D e v i c e s

The first computer storage medium was a punched card. Herman Hollerith’s punched card tabulating machine helped complete the 1890 census in just 2½ years (compared to 8 years for the 1880 census) at a savings of more than $5 million. Hollerith later founded the Tabulating Machine Company, which eventually became known as International Business Machines (IBM). An understanding of storage terms is very important for purchasers, and users, of storage devices.



1 Kilobyte (KB)

≈

1 thousand bytes



1 Megabyte (MB)

≈

1 million bytes



1 Gigabyte (GB)

≈

1 billion bytes



1 Terabyte (TB)

≈

1 trillion bytes



1 Petabyte (PB)

≈

1 quadrillion bytes

1 KB stores approximately ½ page of text. Depending on speed and size, rough costs for RAM are about $40 to $50 per megabyte, while hard disk storage costs are around $0.20 per megabyte.

F l o p p y D i s k s

Although the 5.25-inch floppy disk is physically larger, the storage capacity for a 5.25-inch floppy disk is less than for a comparable 3.5-inch floppy disk. Because of the 3.5-inch floppy disk’s greater durability and superior storage capacity, the 5.25-inch floppy disk at best can be considered a very endangered species. With its rigid plastic shell, it may be difficult to see the 3.5-inch disk as “floppy.”

The name is justified, however, by the disk’s ancestry and the fact that, if the protective shell is removed, the disk on which the data is written is indeed floppy. Today, most new computers (although not the new Apple iMac) come with a 3.5-inch floppy disk drive; a few manufacturers still will, for a price, add a 5.25-inch floppy disk drive.

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The procedure for formatting a floppy disk depends on the operating system. Floppy disks are softsectored, meaning that the number of sectors is not predetermined. The cluster concept creates an odd situation: one file with 100,000 bytes requires less disk space (about 25 clusters at 8 sectors per cluster and 512 bytes per sector) than 1,000 small files of 100 bytes each (1,000 clusters).

A floppy disk spins at about 300 revolutions per minute. When writing data, the floppy disk drive’s read/write head generates electronic impulses that change the magnetic polarity of areas along a track to represent the 1 or 0 bits being recorded. When reading data, the read/write head senses the magnetic areas that have been recorded.

H i g h - C a p a c i t y D i s k s

The three types of high-capacity disks were developed by three different manufacturers: SuperDisk™ is from Imation, HiFD™ is from Sony Electronics, Inc, and the Zip® drive is from Iomega.

Although manufacturers always are concerned about software piracy (unlawfully duplicating or distributing proprietary software), many recommend that users create a backup of programs before installing them on a computer. Backup guards against system failures, such as a head crash, and human errors, such as inadvertently deleting key files. If you ever accidentally delete a file, seek help immediately from a computer support person who sometimes can recover the “erased” file.

H a r d D i s k s

In the early 1980s, hard disk drives were called “Winchester” drives because they had two 30megabyte disks, a characteristic reminiscent of the Winchester 30-30 rifle. In addition to making hard disks more efficient and allowing the installation of multiple operating systems, large hard disks may be partitioned to:



Limit software disasters (which usually are confined to one partition)



Shorten path lengths and assist in file keeping



Save keystrokes (operating systems usually return to the directory they left)



Enhance security (different partitions may warrant different safety levels)



Permit variable frequencies of backup



Allow unattended backups (smaller partitions may fit on a single tape)

Unlike floppy disk read/write heads, hard disk read/write heads do not touch the disk surface. Because of the close tolerance between the disk head and the rotating disk surface, hard disk drives are manufactured in an extremely clean setting, typically cleaner than a hospital operating room. Many hard disk drives are warranted for five years, but most warranties are prorated, meaning that if it fails in the first year it can be replaced at 20 percent of the original cost. All warranties are void, however, if the drive is opened, because contaminated air and dust render the drive unusable.

On a personal computer, a hard disk controller (HDC) is the interface for the hard disk. Many external hard drives use a USB port as their interface. Two other types of HDCs are the EIDE (Enhanced

Integrated Drive Electronics) controller, which can support up to four hard disks, and SCSI (small computer system interface) controllers, which can support multiple disk drives as well as other peripherals.

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A removable hard disk is a disk drive in which a plastic or metal case surrounds the hard disk so that you can remove it from the drive. Two reasonably priced, removable hard disks are the Jaz® disk, which can store up to 2 GB, and the Peerless™ disk, which can store up to 20 GB.

A RAID (redundant array of independent disks) system integrates two or more hard disks, duplicating data, instructions, and information to improve data reliability.

A d v a n t a g e s o f a n I n t e r n e t H a r d D r i v e

When your computer’s hard disk is full, an Internet hard drive can provide additional storage space.

Ease of use, number of features, and amount of storage space varies, based on the specific Internet hard drive Web site. Do you trust the security of online storage services? What types of information might you store online? What are other advantages and disadvantages of Internet hard drives?

C o m p a c t D i s c s

Laser disks first were developed by RCA for showing home movies. The 14-inch optical disk was a derivative of these early 1980s video disks. Advantages that compact discs offer over hard disks include: greater data density, less expense (bit for bit), increased durability, and no head crashing.

C a r i n g f o r C o m p a c t D i s c s

Compare the proper care guidelines for using floppy disks (page 7.9) with the proper care guidelines for using compact discs (page 7.19). How are the guidelines similar? How are they different?

C D - R O M s , C D - R W s , a n d D V D - R O M

On a computer, screen displays for software used to play audio CDs resemble typical CD players, but the controls are accessed with a pointing device. A single CD-ROM can store the entire Encyclopedia

Britannica with room left over. You write on a CD-R using a CD recorder or a CD-R drive and special software. To write on a CD-RW disc, you must have CD-RW software and a CD-RW drive. A multiread CD-ROM drive can read audio CDs, data CDs, CD-Rs, and CD-RWs.

On one side, a DVD-ROM can store up to 13 times the amount of information that can be stored on a

CD-ROM. Double-sided DVD-ROMs (DVD-ROMs that store data on both sides), can store up to 26 times the amount of information stored on a CD-ROM.

A DVD+RW is similar to a CD-RW, except it has storage capacities up to 4.7 GB. To write on

DVD+RW discs, you must have a DVD writer.

Along with processor speed, amount of memory, and hard disk capacity, CD-ROM drive speed is a featured element of almost every personal computer advertisement. Like CD-ROM drives, DVD-ROM drive speeds are indicated with the letter X to represent the standard speed of a DVD drive. That speed, however, is considerably faster than the data transfer rate of the original CD-ROM. While a

24X CD-ROM drive has a data transfer rate of 3,600 KB per second, a 5X DVD-ROM has a data transfer rate of 6,750 KB per second.

T a p e

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Magnetic tape was developed in the mid-1950s to replace the earlier method of storing data on punched cards. To better understand the difference between sequential access and direct access (or random access), compare an audio cassette tape to a CD-ROM. An audio cassette tape is sequential; to listen to the fourth song it is necessary to listen to (or fast-forward through) the first three songs. A CD is direct; it is possible to go straight to the fourth song. For what applications would sequential storage be appropriate? For what applications would it be unsuitable? Tape cartridges can be purchased formatted or unformatted. One-quarter-inch wide cartridge tapes typically are 600 feet long.

Unattended tape backup is a great time saver. Consider how many 1.44 MB floppy disks are needed and how much time is required (removing disks as they become full and inserting new disks) to back up 150 MB of data. With tape backup, you can press a key, go about other business, and return to remove the finished backup tape.

E n t e r p r i s e S t o r a g e S y s t e m s

Large business users often utilize an enterprise storage system strategy. Why? What makes an enterprise storage system strategy attractive to large business users?

P C C a r d s a n d M i n i a t u r e S t o r a g e M e d i a

Smart cards can hold the equivalent of 30 typewritten pages of data and cost from $5 to $50. Smart card readers are about $100. As a storage media for an individual’s medical history, smart cards offer obvious benefits. The cards can be carried in a wallet with, or in lieu of, an insurance card, providing both insurance records and an immediate, up-to-date medical history. A form of smart cards, called

Personal Information Carriers (PICs) is being adopted by the army to replace dog tags. Think of other ways that smart cards and electronic money (e-money) could be used. Will digital cash someday replace conventional currency? Why or why not?

M i c r o f i l m a n d M i c r o f i c h e

Microfilm and microfiche images are so small that they can be read only with a microfilm and microfiche reader. Large organizations use microfilm and microfiche to archive inactive files.

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C H A P T E R 8

O P E R A T I N G S Y S T E M S A N D U T I L I T Y P R O G R A M S

Overview

 Describe the two types of software

 Understand the startup process for a personal computer

 Describe the term user interface

 Explain features common to most operating systems

 Know the difference between stand-alone operating systems and network operating systems

 Identify various stand-alone operating systems

 Identify various network operating systems

 Recognize devices that use embedded operating systems

 Discuss the purpose of the following utilities: file viewer, file compression, diagnostic, uninstaller, disk scanner, disk defragmenter, backup, and screen saver

System software is an essential part of a computer system. This chapter defines system software and discusses two types of system software: operating systems and utility programs. You learn what an operating system is and explore user interfaces, operating systems features, and operating system functions. A variety of popular operating systems are described including DOS, Windows 3.x,

Windows 95, Windows 98, Windows 2000, Windows XP, Windows CE, the Mac OS, OS/2, UNIX,

Linux, and NetWare. You discover what happens when they start a computer and why a boot disk is important. Finally, a number of utility programs are explained.

D e s c r i b e t h e t w o t y p e s o f s o f t w a r e

Two types of software are application software and system software .

Application software consists of programs that perform specific tasks for users, such as a word processing program, e-mail program, or Web browser.

System software consists of the programs that control the operations of a computer and its devices.

The two types of system software are operating systems and utility programs.

An operating system (OS) is a set of programs containing instructions that coordinate all the activities among computer hardware devices.

A utility program performs a specific task, usually related to managing a computer, its devices, or its programs.

U n d e r s t a n d t h e s t a r t - u p p r o c e s s f o r a p e r s o n a l c o m p u t e r

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Booting is the process of starting or restarting a computer.



When you turn on the computer, the power supply sends an electrical signal to devices located in the system unit.



The processor chip resets itself and looks for the ROM chip that contains the BIOS (basic input/output system), which is firmware that holds the startup instructions.



The BIOS executes the power-on self test (POST) to make sure hardware is connected properly and operating correctly.



The POST results are compared with data in a CMOS chip on the motherboard. If the POST completes successfully, the BIOS searches for specific operating system files called system files.



Once located, the boot drive (the drive from which your personal computer starts), loads the system files from storage (the hard disk – usually drive C) into memory (RAM) and executes them.



Next, the kernel of the operating system loads into memory and takes control of the computer.



The operating system loads configuration information. In Windows XP, the registry consists of several file that contain the system configuration information.



When complete, the Windows XP desktop and icons display, and programs in the Start-Up folder are executed.

D e s c r i b e t h e t e r m u s e r i n t e r f a c e

A user interface controls how you enter data and instructions and how information displays on the screen. Two types of user interfaces are command-line and graphical.



With a command-line interface, you type keywords or press special keys to enter data or instructions.



A graphical user interface (GUI) allows you to use menus and visual images such as icons, buttons, and other graphical objects to issue commands.



A menu is a set of commands from which you can choose.



An icon is a small image that represents a program, an instruction, a file, or some other object.

E x p l a i n f e a t u r e s c o m m o n t o m o s t o p e r a t i n g s y s t e m s

Most operating systems perform similar functions that include managing programs, managing memory, scheduling jobs, configuring devices, accessing the Web, monitoring performance, providing housekeeping services, and administering security. Managing programs directly affects your productivity.



A single user/single tasking operating system allows only one user to run one program at a time.

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

A multitasking operating system allows a single user to work on two or more applications that reside in memory at the same time.



A multi-user operating system enables two or more users to run a program simultaneously.



A multiprocessing operating system can support two or more CPUs running programs at the same time. Managing memory involves assigning items to an area of memory while they are being processed. The purpose of memory management is to optimize use of random access memory

(RAM).



With virtual memory (VM), the operating system optimizes memory by allocating a portion of a storage medium, usually the hard disk, to function as additional RAM.



Scheduling jobs (operations the processor manages) involves determining the order in which jobs are processed.

Spooling increases efficiency by placing print jobs in a buffer (an area of memory or storage where data resides while waiting to be transferred) until the printer is ready, freeing the processor for other tasks. Configuring devices establishes communication with each device in the computer. A device driver is a small program that tells the operating system how to communicate with a device. Accessing the Web may entail including a Web browser and e-mail program in the operating system. Monitoring performance helps to identify and solve system problems.

A performance monitor is a program that assesses and reports information about various system resources and devices. Providing housekeeping services entails performing storage and file management functions. A file manager performs such functions as formatting and copying disks; listing the files on a storage medium; checking the amount of used and unused space on a storage medium; organizing, copying, deleting, moving, and sorting files; and creating shortcuts (icons on the desktop that run a program when clicked).

Administering security involves establishing user accounts on a network. Each account typically requires a user name and a password to log on, or access, the network.

K n o w t h e d i f f e r e n c e b e t w e e n s t a n d - a l o n e o p e r a t i n g s y s t e m s a n d n e t w o r k o p e r a t i n g s y s t e m s

A stand-alone operating system is a complete operating system that works on a desktop or notebook computer. A network operating system (also called network OS or NOS) is an operating system that supports a network. A network is a collection of computers and devices connected together via communications media and devices such as cables, telephone lines, and modems. In some networks, the server is the computer that controls access to the hardware and software on a network and provides a centralized storage area. The other computers on the network, called clients, rely on the server(s) for resources.

I d e n t i f y v a r i o u s s t a n d - a l o n e o p e r a t i n g s y s t e m s

Stand-alone operating systems include DOS, Windows 3.x, Windows 95, Windows NT Workstation,

Windows 98, Windows 2000 Professional, Windows Millennium Edition, Windows XP Home

56


Edition, Windows XP Professional Edition, Mac OS, OS/2 Warp Client, UNIX, and Linux. UNIX and

Linux also function as network operating systems.



DOS (Disk Operating System ) refers to several single user, command-line and menu-driven operating systems developed in the early 1980s for personal computers.



Windows 3.x

refers to early operating environments that, although not operating systems, provided a graphical user interface to work in combination with DOS and simplify its use.



Windows 95 is a true multitasking operating system – not an operating environment – with an improved graphical interface.



Windows NT Workstation is a client operating system that can connect to a Windows NT Server.



Developed as an upgrade to Windows 95, the Windows 98 operating system is easier to use and more integrated with the Internet. Windows 98 includes Microsoft Internet Explorer, a popular

Web browser, Windows Explorer, a file manager, and an Active Desktop™ that works similarly to Web links.



Windows 2000 Professional is a complete, reliable multitasking client operating system for business desktop and business notebook computers.



Windows Millennium Edition is an operating system that has features specifically for the home user.



Windows XP is Microsoft’s fastest, most reliable Windows operating system, providing quicker startup, better performance, and a new, simplified visual look.



Windows XP Home Edition is an upgrade to Windows Millennium Edition, while Windows XP

Professional Edition is an upgrade to Windows 2000 Professional.



The Mac OS, the latest version of the Macintosh operating system (the first commercially successful graphical user interface), is a multitasking operating system available only on Apple computers.



OS/2 Warp Client is IBM’s GUI multitasking client operating system that supports networking,

Java, the Internet, and speech recognition.

I d e n t i f y v a r i o u s n e t w o r k o p e r a t i n g s y s t e m s

Network operating systems include NetWare, Windows NT Server, Windows 2000 Server, Windows

.NET Server, OS/2 Warp Server for E-business, UNIX, Linux, and Solaris™.

 Novell’s NetWare

is a widely used network operating system designed for client/server networks.



Windows NT Server is the operating system used by servers in the Windows NT client/server network environment.



The Windows 2000 Server family consists of three products:



Windows 2000 Server (for the typical business network),



Windows 2000 Advanced Server (for e-commerce applications), and



Windows 2000 Database server (for demanding, large-scale applications).



Windows .NET Server is an upgrade to Windows 2000 Server. The Windows .NET Server family includes four products:



Windows .NET Standard Server (for the typical small- to medium-sized business network),

57




Windows .NET Enterprise Server (for medium- to large-sized businesses, including those with e-commerce applications),



Windows .NET Datacenter (for business with huge volumes of transactions and large-scale databases), and



Windows .NET Web Server (for Web server and Web hosting businesses).



OS/2 Warp Server for E-business is IBM’s network operating system designed for all sizes of business.



UNIX is a multitasking, command-line operating system implemented on many different types of computers. Because it is both a stand-alone operating system and a network operating system, some call UNIX a multipurpose operating system.



Linux is a popular, free, multitasking UNIX-type operating system.

 Solaris™

, a version of UNIX developed by Sun Microsystems, is a network operating system designed for e-commerce applications.

R e c o g n i z e d e v i c e s t h a t u s e e m b e d d e d o p e r a t i n g s y s t e m s

The operating system on most handheld computers and small devices, called an embedded operating system, resides on a ROM chip. Popular embedded operating systems include Windows CE, Pocket

PC OS, and Palm OS®.

Windows CE is a scaled-down Windows operating system designed for use on wireless communications devices and smaller computers such as handheld computers, in-vehicle devices, and

Web-enabled devices.

Pocket PC OS is a scaled-down operating system developed by Microsoft that works on a specific type of handheld computer, called a Pocket PC.

The Palm OS® is the operating system used on Palm handheld computers from Palm, Inc., and Visor handheld computers from Handspring™.

Discuss the purpose of the following utilities: file viewer, file compression, diagnostic, uninstaller, disk scanner, disk defragmenter, backup, and screen saver

Most operating systems include several utility programs that perform specific tasks related to managing a computer, its devices, or its programs.



File viewer is a utility that allows you to display and copy the contents of a file.



A file compression utility shrinks the size of a file.



A diagnostic utility compiles technical information about a computer’s hardware and certain system software programs and then prepares a report outlining any identified problems.



An uninstaller is a utility that removes an application, as well as any associated entries in the system files.



A disk scanner is a utility that (1) detects and corrects both physical and logical problems on a hard disk, and (2) searches for and removes unnecessary files.



A disk defragmenter is a utility that reorganizes files and unused space on a computer’s hard disk so data can be accessed more quickly and programs can run faster.

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

A backup utility copies, or backs up, selected files or an entire hard drive onto another disk or tape.



A screen saver is a utility that causes the monitor’s screen to display a moving image on a blank screen if no keyboard activity occurs for a specified period.






System software

Starting a computer















User interface

Features of operating systems

Stand-alone and network operating system

Stand-alone operating systems

Network operating systems

Embedded operating systems

Utility programs

S y s t e m S o f t w a r e

Software is a key component of any information system. Of the total number of corporate dollars spent on computing, the software share is increasing while the hardware share is decreasing. Typically, different sizes of computers use different operating systems, and even the same types of computers may not use the same operating system. The operating system that a computer uses sometimes is called the software platform, or platform. Application software packages often require a specific software platform. A cross-platform application, however, is one that runs on multiple operating systems.

S t a r t i n g a C o m p u t e r

When you turn on a computer after it has been powered off, you are performing a cold boot . When you restart a computer that already has been powered on, you are performing a warm boot. Your typically can perform a warm boot by pressing a combination of keys on the keyboard (in Windows,

CTRL+ALT+DEL), selecting options from a menu, or pressing a Reset button on the computer.

If you watch the screen closely as the POST is conducted, the value for the total amount of memory can be seen to change as it is measured in the memory test. If the POST results do not match the data on the CMOS chip, an appropriate message should appear. The boot program typically is the first side, first track, and first sector of the hard disk. When you install an operating system, one of the installation steps involves making an emergency disk from which you can start your computer if the hard disk is damaged.

U s e r I n t e r f a c e

You can interact with an operating system directly (as you do when copying files, moving files, formatting disks, and so on) or indirectly (as you do when working with an application program). An operating system is intended to be transparent; that is, it does not have to be understood, considered, or even known. The operating system with which an application program will work is specified on the application software package. The application programs you want to use should be considered before

59

B a s i c I n f o r m a t i o n T e c h n o l o g y C o n c e p t s deciding on an operating system, and the operating system must be considered when choosing application software.

A graphical user interface is designed to be easier to use (more user-friendly) than a command-line interface. As an example of this user-friendly nature, consider how a relatively simple task, such as deleting a file, is performed with a command-line interface and with a GUI. With a command-line interface, you might type DEL followed by the file name in quotation marks. Therefore, you must remember the command, type it correctly, and use the proper syntax. On the other hand, with a GUI you need only select (click) the file name in the file manager window and then click the Delete command on a menu or the Delete button on a toolbar. Although most people find a GUI the easiest interface to use, some long-time computer virtuosos still feel a command-line user interface is more efficient.

F e a t u r e s o f O p e r a t i n g S y s t e m s

Early operating systems were single user/single tasking , but today most operating system are multitasking. Multitasking can be cooperative, in which programs switch when they reach a logical break point, or pre-emptive, in which programs switch based on priority and an allocated amount of time. Early versions of Windows used cooperative multitasking; Windows 95 and subsequent versions use pre-emptive multitasking. Upon termination, most programs relinquish their space in memory, which then is reallocated by the operating system. Some programs, however, stay in memory after they terminate. As a class, these programs are called TSR (Terminate and Stay Resident) programs.

Virtual memory is employed with multitasking operating systems to maximize the number of programs that can use memory at one time. Paging, or the technique of swapping items between memory and storage, was developed before processors could address directly more than 1 MB of memory. All printers have buffers, and printer manufacturers are eager to sell DRAM. The term spooling comes from the observation that placing print jobs temporarily in a buffer is somewhat like winding thread onto a spool so that it can be used at a later time. Today, adding and configuring devices is easier because most devices support Plug and Play, which means the computer can recognize a new device and automatically load the necessary drivers. A feature of Windows 95, Plug and Play initially was greeted with mixed reviews. In fact, some wags claimed the new technology was more accurately called, “Plug and Pray.”

Processor utilization – the amount of time that the processor is working and not idle – is one way of monitoring system performance. In addition to the programs that come with most operating systems, several utility programs are available to monitor system performance. Formatting a disk is the process of preparing it for reading and writing. Today, most floppy and hard disks are preformatted by the manufacturer. If you format a disk that already contains data, the formatting process erases the file location information, but it does not erase the actual files on the disk. Therefore, if you accidentally format a disk, often you can unformat it with a utility program. System security usually is most important for large systems or networks. For single-user PCs, adequate system security can be a key in the user’s pocket.

S t a n d - A l o n e a n d N e t w o r k O p e r a t i n g S y s t e m

Many early operating systems were device dependent and proprietary. Device-dependent operating systems run only on a specific type of computer. Proprietary software is privately owned and limited to a specific vendor or computer mode. Today, the trend is towards device-independent operating

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B a s i c I n f o r m a t i o n T e c h n o l o g y C o n c e p t s systems that run on many manufacturers’ computers. Software that is not proprietary (i.e., that can work with a variety of computer models) sometimes is called portable or generic. Most of the operating systems discussed in this section are portable. When an operating system is proprietary, usually it is to boost hardware sales.

Operating systems for Apple computers and most mainframes initially were proprietary. Steve

Wozniak, cofounder of Apple Computers, believes the decision to make its innovative Macintosh operating system proprietary was one of the company’s greatest mistakes. “We had the most beautiful operating system,” Wozniak writes, “but to get it you had to buy our hardware at twice the price.”

Wozniak now feels the operating system should have been licensed.

S t a n d - A l o n e O p e r a t i n g S y s t e m s

Bill Gates, founder of Microsoft and one of the wealthiest men in the world, began his fortune with the

MS-DOS operating system. Although developed for IBM, Microsoft retained the rights to the operating system and licensed the source code to several hardware manufacturers, which resulted in multiple variations. An application written for one type of DOS, however, will work with any other variation. A number follows each version of PC-DOS or MS-DOS. The integer portion of the number indicates a major release, while the decimal portion indicates updates. Thus, MS-DOS 6.2 means major version six, which has been updated twice. To a great extent, the popularity of DOS was a result of the large number of applications written to work with the operating system.

Windows 1.0, released in 1985, was Microsoft’s first attempt with a graphical user interface. It was not until five years later, however, with the release of Windows 3.0, that computer users began to take

Windows seriously. Windows required 2 MB of memory (with 4 MB recommended) and an 80386 or newer processor, so it could not be used with many older PCs. Nevertheless, because Windows 3.0 was easier to use than DOS, eventually most software was written, and many popular DOS programs were rewritten, to work with Windows.

Despite the advantages of Windows 95 and a heavily-funded promotional campaign, a poll of DOS and Windows 3.x users showed not everyone immediately embraced the new operating system. When asked how likely they were to adopt Windows 95 within the next six months, respondents replied:

 extremely likely 10%

 possible 35%

 not likely 53%

 don’t know 2%

W h y a r e p e o p l e o f t e n r e l u c t a n t t o a d o p t a n e w o p e r a t i n g s y s t e m ?

The inclusion of Internet Explorer in the Windows 98 operating system led to an antitrust suit against

Microsoft. Prosecutors insisted that the incorporation of a browser was an attempt by Microsoft to eliminate competition from rival Web browsers (such as Netscape Navigator). Microsoft maintained that the addition simply was an enhancement to the operating system. Although Microsoft advertised

Windows 98 less heavily than Windows 95, many vendors took up the slack. One retailer offered

Windows 98 with the opportunity to buy a new computer for $98. The promotion evidently worked. A buyer waited in line 11 hours for a chance to buy the new operating system and discount computer.

When asked if he would have come out simply for Windows 98 (his current computer ran Windows

3.1), he replied, “Not a chance.”

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Windows 2000 was released in February, 2000 and was touted as a boon for all businesses, from small companies with no more than two desktop computers to large corporations with vast networks.

Windows Millennium is a result of Microsoft’s recognition that the needs of business and home users are different.

For years, the Macintosh operating system had features that made it far easier to use than other operating systems. For example, people could give files sensible names (like “Letter to Grandma”) instead of the cryptic, eight-character strings (like “letgrand.txt”) demanded by DOS and Windows

3.x. While Windows 95 incorporated many of these features, Macintosh devotees still feel their operating system is easier to use. Until recently, the Macintosh operating system was proprietary. In

1994 the operating system was licensed, but experts feel Apple’s promotion has been lukewarm. New standards let IBM computers run Apple software. More than 4,000 applications are designed to run under the Mac OS. Microsoft has developed the more popular Mac OS applications.

IBM supplies OS/2 (Operating System/2) Warp with its high-end personal computers. OS/2 originally was developed jointly by IBM and Microsoft to replace MS-DOS. As an interim measure, Microsoft developed Windows, an operating environment to work with DOS. The eventual popularity of

Windows, coupled with the initial poor sales of OS/2, resulted in Microsoft and IBM going their separate ways, with Microsoft concentrating on Windows and IBM continuing to develop OS/2.

Features offered in OS/2 Warp include:





An enhanced graphical user interface

 Integrated business application software

Speaker-independent speech recognition software





Desktop objects that allow users to connect directly to the Internet

 Integrated Java programming language that allows Java applications to run without a Web browser

Support for multiple CPUs using multiprocessing

N e t w o r k O p e r a t i n g S y s t e m s

Many consider UNIX to be the most portable operating system. Although it has some shortcomings,

UNIX often is used in “turnkey” systems designed for retail stores, doctors, dentists, veterinarians, and other small- to medium-businesses. Do you know what operating system is mentioned in the film

Jurassic Park? UNIX.

Despite the current dominance of Windows, some believe Linux is the operating system of the future.

Because Linux is freeware, users can modify and improve the program code. In addition, Linux is capable of running efficiently with less powerful processors, even the 80386. The story of Linux’s originator, Linus Torvalds, is told in the Technology Trailblazer on page 8.25.

E m b e d d e d O p e r a t i n g S y s t e m s

The latest Palm handheld computer, Palm IIIC, offers a colour screen. When paired with a portable, expandable, attachable, nearly full-sized keyboard and file compression software, some reviewers say the Palm IIIC almost can replace a laptop. The Visor handheld computer runs the same operating system as the Palm but offers several additional features – videogames, cell telephone, modem, MP3 player, and two-way pager – at about half the cost.

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U t i l i t y P r o g r a m s

Utilities generally reside in storage until summoned by the user or operating system kernel. Microsoft was the target of several lawsuits for allegedly incorporating utility programs developed by others into their DOS operating system. Some versions of DOS were modified because of this litigation. In light of the ever-increasing number of utility programs included with operating systems, will a market remain for separate utility programs?

In addition to the utilities mentioned in this chapter, other Windows 98 utilities include:



DirectX – Enhances multimedia capabilities on the computer, providing better playback of different types of multimedia and managing 3-D graphics better than console computers.



Drive Converter (FAT 32) – Converts the hard drive to the FAT32 file system, an enhancement that stores data more efficiently, creating extra disk space and helping programs run faster.



Registry Checker – Finds and fixes registry problems each time the computer is started, automatically scanning the registry for inconsistent data structures.



System File Checker – Keeps track of critical files that make the computer run, restoring the files if they are moved or changed.



Microsoft Magnifier – Makes the screen more readable by displaying a magnified portion in a separate window and making it possible to alter the colour scheme and contrast of the magnification window for easier visibility.

S o m e s t a n d - a l o n e u t i l i t i e s i n c l u d e :



Desktop enhancers – Change the desktop look and organization, allowing users to create and switch between multiple desktops.



File conversion – Converts from one file format to another so that a file can be used by another application.



Internet organizers – Helps in the management and use of favorite Web sites, searching the Web and reporting on site changes.



Antivirus programs – Prevent, detect, and remove computer viruses.

Some utility programs are used primarily by select groups. For example, text editors -- utility programs that make it easy to work with lists and records -- are popular with programmers and people who work with databases. PC Tools and Norton Utilities are popular utility software packages for personal computers.

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