Technology Guide 1 Hardware

Technology Guide

Hardware

1

[ LEARNING OBJECTIVES ] [ TECHNOLOGY GUIDE OUTLINE ] [ WEB RESOURCES ]

1. Identify the major hardware components of a computer system.

2. Discuss strategic issues that link hardware design to business strategy.

3. Describe the hierarchy of computers according to power and their respective roles.

4. Differentiate the various types of input and output technologies and their uses.

5. Describe the design and functioning of the central processing unit.

6. Discuss the relationships between microprocessor component designs and performance.

7. Describe the main types of primary and secondary storage.

8. Distinguish between primary and secondary storage along the dimensions of speed, cost, and capacity.

TG 1.1 Introduction

TG 1.2 Strategic Hardware Issues

TG 1.3 Computer Hierarchy

TG 1.4 Input and Output Technologies

TG 1.5 The Central Processing Unit

• Student PowerPoints for note taking

• E-book

• Author video lecture for each chapter section

• Practice quizzes

• Flash Cards for vocabulary review

• Additional “IT’s About Business” cases

• Video interviews with managers

• Lab Manuals for Microsoft Offi ce 2010 and 2013

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439

As you begin this Technology Guide, you might be wondering, why do I have to know anything about hardware? There are several reasons why you will benefi t from understanding the basics of hardware. First, regardless of your major (and future functional area in an organization), you will be using different types of

hardware throughout your career. Second, you will have input concerning the hardware you will use. In this capacity you will be required to answer many questions, such as “Is my hardware performing adequately for my needs? If not, what types of problems am I experiencing?” Third, you will also have input into decisions when your functional area or organization upgrades or replaces its hardware. MIS employees will act as advisors, but you will provide important input into such decisions. Finally, in some organizations, the budget for hardware is allocated to functional areas or departments. In such cases, you might be making hardware decisions (at least locally) yourself.

This Technology Guide will help you better understand the hardware decisions your orga-nization must make as well as your personal computing decisions. Many of the design prin-ciples presented here apply to systems of all sizes, from an enterprisewide system to your home computer system. In addition, the dynamics of innovation and cost that you will read about can affect personal as well as corporate hardware decisions.

Introduction to HardwareRecall from Chapter 1 that the term hardware refers to the physical equipment used for the input, processing, output, and storage activities of a computer system. Decisions about hard-ware focus on three interrelated factors: appropriateness for the task, speed, and cost. The incredibly rapid rate of innovation in the computer industry complicates hardware decisions because computer technologies become obsolete more quickly than other organizational technologies.

The overall trends in hardware are that it becomes smaller, faster, cheaper, and more pow-erful over time. In fact, these trends are so rapid that they make it diffi cult to know when to purchase (or upgrade) hardware. This diffi culty lies in the fact that companies that delay hard-ware purchases will, more than likely, be able to buy more powerful hardware for the same

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440 TECHNOLOGY GUIDE 1 Hardware

amount of money in the future. It is important to note that buying more powerful hardware for the same amount of money in the future is a trade-off. An organization that delays purchas-ing computer hardware gives up the benefi ts of whatever it could buy today until the future purchase date arrives.

Hardware consists of the following:

• Central processing unit (CPU). Manipulates the data and controls the tasks performed by the other components.

• Primary storage. Temporarily stores data and program instructions during processing.• Secondary storage. Stores data and programs for future use.• Input technologies. Accept data and instructions and convert them to a form that the

computer can understand.• Output technologies. Present data and information in a form people can understand.• Communication technologies. Provide for the fl ow of data from external computer

networks (e.g., the Internet and intranets) to the CPU, and from the CPU to computer networks.

Strategic Hardware IssuesFor most businesspeople the most important issues are what the hardware enables, how it is advancing, and how rapidly it is advancing. In many industries, exploiting computer hardware is a key to achieving competitive advantage. Successful hardware exploitation comes from thoughtful consideration of the following questions:

• How do organizations keep up with the rapid price reductions and performance advance-ments in hardware? For example, how often should an organization upgrade its computers and storage systems? Will upgrades increase personal and organizational productivity? How can organizations measure such increases?

• How should organizations determine the need for the new hardware infrastructures, such as server farms, virtualization, grid computing, and utility computing? (We discuss these technologies in Technology Guide 3.)

• Portable computers and advanced communications technologies have enabled employees to work from home or from anywhere. Will these new work styles benefi t employees and the organization? How do organizations manage such new work styles?

Computer HierarchyThe traditional standard for comparing classes of computers is their processing power. This sec-tion presents each class of computers, from the most powerful to the least powerful. It describes both the computers and their roles in modern organizations.

SupercomputersThe term supercomputer does not refer to a specifi c technology. Rather, it indicates the fast-est computers available at any given time. At the time of this writing (mid-2013), the fastest supercomputers had speeds exceeding 1 petafl op (1 petafl op is 1,000 trillion fl oating point operations per second). A fl oating point operation is an arithmetic operation that involves decimals.

Because supercomputers are costly as well as very fast, they are generally used by large organizations to execute computationally demanding tasks involving very large data sets. In contrast to mainframes, which specialize in transaction processing and business

TG 1.2

TG 1.3


441SECTION TG 1.3 Computer Hierarchy

applications, supercomputers typically run military and scientifi c applications. Although they cost millions of dollars, they are also being used for commercial applications where huge amounts of data must be analyzed. For example, large banks use supercomputers to calculate the risks and returns of various investment strategies, and healthcare organiza-tions use them to analyze giant databases of patient data to determine optimal treatments for various diseases.

Mainframe ComputersAlthough mainframe computers are increasingly viewed as just another type of server, albeit at the high end of the performance and reliability scales, they remain a distinct class of sys-tems differentiated by hardware and software features. Mainframes remain popular in large enterprises for extensive computing applications that are accessed by thousands of users at one time. Examples of mainframe applications are airline reservation systems, corporate payroll programs, Web site transaction processing systems (e.g., Amazon and eBay), and student grade calculation and reporting.

Today’s mainframes perform at terafl op (trillions of fl oating point operations per second) speeds and can handle millions of transactions per day. In addition, mainframes provide a secure, robust environment in which to run strategic, mission-critical applications.

Midrange ComputersLarger midrange computers, called minicomputers, are relatively small, inexpensive, and compact computers that perform the same functions as mainframe computers, but to a more limited extent. In fact, the lines between minicomputers and mainframes have blurred in both price and performance. Minicomputers are a type of server—that is, a computer that supports computer networks and enables users to share fi les, software, peripheral devices, and other resources. Mainframes are a type of server as well because they provide support for entire enterprise networks.

MicrocomputersMicrocomputers—also called micros, personal computers, or PCs—are the smallest and least expensive category of general-purpose computers. It is important to point out that people fre-quently defi ne a PC as a computer that utilizes the Microsoft Windows operating system. In fact, a variety of PCs are available, and many of them do not use Windows. One well-known example is Apple Macs, which use the Mac OS X operating system (discussed in Technology Guide 2). The major categories of microcomputers are desktops, thin clients, notebooks and laptops, netbooks, and tablets.

Desktop PCs The desktop personal computer is the familiar microcomputer system that has become a standard tool for business and the home. A desktop generally includes a central processing unit (CPU)—which you will learn about later—and a separate but con-nected monitor and keyboard. Modern desktop computers have gigabytes of primary storage, a rewriteable CD-ROM drive and a DVD drive, and up to several terabytes of secondary storage. Today, desktops are being replaced with portable devices such as laptops, netbooks, and tablets.

Thin-Client Systems Before you address thin-client systems, recall that servers are com-puters that provide a variety of services for clients, including running networks, processing Web sites, processing e-mail, and many other functions. Clients are typically computers on which users perform their tasks, such as word processing, spreadsheets, and others.

Thin-client systems are desktop computer systems that do not offer the full functionality of a PC. Compared to PCs, or fat clients, thin clients are less complex, particularly because they do not have locally installed software. When thin clients need to run an application, they access it from a server over a network instead of from a local disk drive.

For example, a thin client would not have Microsoft Offi ce installed on it. Thus, thin cli-ents are easier and less expensive to operate and support than PCs. The benefi ts of thin clients include fast application deployment, centralized management, lower cost of ownership, and



easier installation, management, maintenance, and support. The main disadvantage of thin clients is that if the network fails, then users can do very little on their computers. In contrast, if users have fat clients and the network fails, they can still perform some functions because they have software, such as Microsoft Offi ce, installed on their computers.

Laptop and Notebook Computers Laptop computers (or notebook computers) are small, easily transportable, lightweight microcomputers that fi t comfortably into a briefcase (Figure TG 1.1). Notebooks and laptops are designed to be as convenient and easy to trans-port as possible. Just as important, they also provide users with access to processing power and data outside an offi ce environment. However, they cost more than desktops for similar functionality.

Netbooks A netbook is a very small, lightweight, low-cost, energy-effi cient, portable com-puter. Netbooks are generally optimized for Internet-based services such as Web browsing and e-mail.

Tablet Computers A tablet computer (or tablet) is a complete computer contained entirely in a fl at touch screen that users operate via a stylus, digital pen, or fi ngertip instead of a keyboard or mouse. Examples of tablets are the Apple iPad 3 (www.apple.com/ipad), the HP Slate 2 (www.hp.com), the Toshiba Thrive (www.toshiba.com), and the Motorola Xoom 2 (www.motorola.com).

Wearable ComputersWearable computers are miniature computers that people wear under, with, or on top of their clothing. Key features of wearable computers are that there is constant interaction between the computer and the users and that the users can multitask, meaning they do not have to stop what they are doing to utilize the device. Examples of wearable comput-ers are the iPod Nano (www.apple.com/ipod-nano) with a wristwatch attachment, the Sony SmartWatch (www.sony.com/SmartWatch), the Apple iWatch (planned for release in mid-to-late 2013), Google Glass, and Vuzix (www.vuzix.com) M100Smart Glasses (a Google Glass competitor). For a closer look at Google Glass (www.google.com/glass/start), see IT’s About Business 3.3.

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Motorola Xoom tablet

Netbook

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443SECTION TG 1.4 Input and Output Technologies

Google Glass is an excellent example of a device that provides augmented reality. Aug-mented reality is a live, direct or indirect, view of a physical, real-world environment whose elements are augmented, or enhanced, by computer-generated sensory input such as sound, video, graphics, or GPS data. That is, augmented reality enhances the user’s perception of reality. Note that in contrast, virtual reality replaces the real world with a simulated world.

As an example of augmented reality with Google Glass, let’s say that you are looking for a destination in an unfamiliar city. You ask Google Glass for directions, and the device will overlay your vision with a graphic display of a street map, with the route to your destination highlighted.

IT’s Personal: Purchasing a Computer

One day you will purchase a computer for yourself or your job.

When that day comes, it will be important for you to know what to

look for. Buying a computer can be very confusing if you just read

the box. This Technology Guide has explained the major hardware

components of a computer. There are more things you need to

consider, however, when you purchase a computer: what you plan

to do with it, where you plan to use it, and how long you need ser-

vice from it. Let’s look at each question more closely.

• What do you plan to do with your computer? Consider that

when you buy a vehicle, your plans for using the vehicle

determine the type of vehicle you will purchase. The same

rules apply to purchasing a computer. You need to consider

what you currently do with a computer and what you may

do before you replace the one under consideration. Although

many people simply buy as much as they can afford, they

may overpay because they do not consider what they need

the computer for.

• Where do you plan to use your computer? If you only plan

to use it at home at your desk, then a desktop model will be

fi ne. In general, you can get more computer for your money in

a desktop model as opposed to a laptop (i.e., you pay extra

for mobility). However, if you think you may want to take the

computer with you, then you will need some type of a lap-

top or tablet computer. When portability is a requirement, you

will want to reconsider what you plan to use the computer for

because as computers become more portable (smaller), their

functionality changes, and you want to make sure the com-

puter will meet your needs.

• How long do you need service from this computer? Today, we

anticipate that most of the devices we purchase will become

outdated and need to be replaced in a few years. Therefore,

the length of service is really more about warranty and the

availability of repair services. In some cases, you should base

your purchase decision on these issues rather than speed

because they can extend the life of your computer.

Input and Output TechnologiesInput technologies allow people and other technologies to enter data into a computer. The two main types of input devices are human data-entry devices and source-data automation devices. As their name implies, human data-entry devices require a certain amount of human effort to input data. Examples are keyboard, mouse, pointing stick, trackball, joystick, touch screen, stylus, and voice recognition.

In contrast, source-data automation devices input data with minimal human intervention. These technologies speed up data collection, reduce errors, and gather data at the source of a transaction or other event. Bar code readers are an example of source-data automation. Table TG 1.1 describes the various input devices.

The output generated by a computer can be transmitted to the user via several output devices and media. These devices include monitors, printers, plotters, and voice. Table TG 1.2 describes the various output devices.

Multimedia technology is the computer-based integration of text, sound, still images, ani-mation, and digitized motion video. It usually consists of a collection of various input and

TG 1.4



Table TG 1.1Input Devices

Input Device Description

Human Data-Entry Devices

Keyboards Most common input device (for text and numerical data).

Mouse Handheld device used to point the cursor at a point on screen, such as an icon; the

user clicks a button on the mouse, instructing the computer to take some action.

Optical mouse The mouse is not connected to computer by a cable; rather, it uses camera chip to

take images of surface it passes over, comparing successive images to determine its

position.

Trackball User rotates a ball built into top of device to move the cursor (rather than moving an

entire device such as a mouse).

Pointing stick Small button-like device; the cursor moves in the direction of the pressure the user

places on the stick. Located between the keys near the center of the keyboard.

Touchpad User moves the cursor by sliding a fi nger across a sensitized pad and then can tap

the pad when the cursor is in (also called a trackpad) the desired position to instruct

the computer to take action (also called glide-and-tap pad).

Graphics tablet A device that can be used in place of, or in conjunction with, a mouse or trackball;

it has a fl at surface for drawing and a pen or stylus that is programmed to work with

the tablet.

Joystick The joystick moves the cursor to the desired place on the screen; commonly used in

video games and in workstations that display dynamic graphics.

Touch screen Users instruct computer to take some action by touching a particular part of the

screen; commonly used in information kiosks such as ATM machines. Touch screens

now have gesture controls for browsing through photographs, moving objects

around on a screen, fl icking to turn the page of a book, and playing video games. For

example, see the Apple iPhone.

Stylus Pen-style device that allows user either to touch parts of a predetermined menu of

options or to handwrite information into the computer (as with some PDAs); works

with touch-sensitive screens.

Digital pen Mobile device that digitally captures everything you write; built-in screen confi rms

that what you write has been saved; also captures sketches, fi gures, and so on with

on-board fl ash memory.

Web camera (Webcam) A real-time video camera whose images can be accessed via the Web or instant

messaging.

Voice-recognition Microphone converts analog voice sounds into digital input for a computer; critical

technology for physically challenged people who cannot use other input devices.

output technologies. Multimedia merges the capabilities of computers with televisions, CD players, DVD players, video and audio recording equipment, and music and gaming tech-nologies. High-quality multimedia processing requires powerful microprocessors and extensive memory capacity, including both primary and secondary storage.


445SECTION TG 1.4 Input and Output Technologies

Table TG 1.1 (Continued)

Input Device Description

Gesture-Based Input

Gesture recognition refers to technologies that enable computers to interpret human gestures. These technologies

would be the fi rst step in designing computers that can understand human body language. This process creates a

richer interaction between machines and humans than has been possible via keyboards, graphical user interfaces,

and the mouse. Gesture recognition enables humans to interact naturally with a computer without any intervening

mechanical devices. With gesture-based technologies, the user can move the cursor by pointing a fi nger at a computer

screen. These technologies could make conventional input devices (the mouse, keyboards, and touch screens)

redundant. Examples of gesture-based input devices are the Nintendo Wii (www.nintendo.com/wii), the Microsoft

Kinect (www.xbox.com/kinect), and the Leap Motion controller (www.leapmotion.com).

Wii A video game console produced by Nintendo. A distinguishing feature of the Wii is its

wireless controller, which can be used as a handheld pointing device and can detect

movement in three dimensions.

Microsoft Kinect A device that enables users to control and interact with the Xbox 360 through a

natural interface using gestures and spoken commands. Kinect eliminates the need

for a game controller.

Leap Motion Controller A motion-sensing, matchbox-sized device placed on a physical desktop. Using

two cameras, the device “observes” an area up to a distance of about three feet. It

precisely tracks fi ngers or items such as a pen that cross into the observed area. The

Leap can perform tasks such as navigating a Web site, using pinch-to-zoom gestures

on maps, performing high-precision drawing, and manipulating complex three-

dimensional visualizations. The smaller observation area and higher resolution of the

device differentiates it from the Microsoft Kinect, which is more suitable for whole-

body tracking in a space the size of a living room.

Source-Data Automation Input Devices

Automated teller machine

(ATM)

A device that includes source-data automation input in the form of a magnetic stripe

reader; human input via a keyboard; and output via a monitor, printer, and cash

dispenser.

Magnetic stripe reader A device that reads data from a magnetic stripe, usually on the back of a plastic card

(e.g., credit and debit cards).

Point-of-sale terminals Computerized cash registers that also may incorporate touch screen technology and

bar code scanners to input data such as item sold and price.

Barcode scanners Devices that scan black-and-white bar code lines printed on merchandise labels.

Optical mark reader Scanner for detecting the presence of dark marks on a predetermined grid, such as

multiple-choice test answer sheets.

Magnetic ink character reader A device that reads magnetic ink printed on checks that identify the bank, checking

account, and check number.

Optical character recognition Software that converts text into digital form for input into computer.

Sensors Devices that collect data directly from the environment and input data directly into

computer; examples are vehicle airbag activation sensors and radio-frequency

identifi cation (RFID) tags.

Cameras Digital cameras capture images and convert them into digital fi les.

Radio Frequency) Identifi cation

(RFID)

Uses technology that uses active or passive tags (transmitters) to wirelessly transmit

product information to electronic readers. (We discuss RFID in detail in Chapter 8.



The Central Processing UnitThe central processing unit (CPU) performs the actual computation or “number crunching” inside any computer. The CPU is a microprocessor (e.g., Intel’s Core i3, i5, and i7 chips with more to come) made up of millions of microscopic transistors embedded in a circuit on a sili-con wafer or chip. For this reason, microprocessors are commonly referred to as chips.

TG 1.5

Table TG 1.2Output Devices

Output Device Description

Monitors

Cathode ray tubes Video screens on which an electron beam illuminates pixels on a display screen.

Liquid crystal display (LCDs) Flat displays that have liquid crystals between two polarizers to form

characters and images on a backlit screen.

Flexible displays Thin, plastic, bendable computer screens.

Organic light-emitting diodes (OLEDs) Displays that are brighter, thinner, lighter, cheaper, faster, and take less

power to run displays than LCDs.

Retinal scanning displays Project image directly onto a viewer’s retina; used in medicine, air traffi c

control, and controlling industrial machines.

Heads-up displays Any transparent display that presents data without requiring the user to

look away from his or her usual viewpoint; for example, see Microvision

(www.microvision.com).

Printers

Laser Use laser beams to write information on photosensitive drums; produce

high-resolution text and graphics.

Inkjet Shoot fi ne streams of colored ink onto paper; usually less expensive to

buy than laser printers but can be more expensive to operate; can offer

resolution quality equal to laser printers.

Thermal Produces a printed image by selectively heating coated thermal paper;

when the paper passes over the thermal print head, the coating turns black

in the areas where it is heated, producing an image.

Plotters Use computer-directed pens for creating high-quality images, blueprints,

schematics, drawing of new products, and so on.

Voice Output A speaker/headset that can output sounds of any type; voice output is a

software function that uses this equipment.

Electronic Book Reader A wireless, portable reading device with access to books, blogs,

newspapers, and magazines. On-board storage holds hundreds of books

(e.g., Amazon Kindle, Sony Reader, Barnes and Noble Nook).

Pocket Projector A projector in a handheld device that provides an alternative display method

to alleviate the problem of tiny display screens in handheld devices. Pocket

projectors will project digital images onto any viewing surface (e.g., see the

Pico Projector).


447SECTION TG 1.5 The Central Processing Unit

As shown in Figure TG 1.2, the microprocessor has different parts, which perform differ-ent functions. The control unit sequentially accesses program instructions, decodes them, and controls the fl ow of data to and from the arithmetic-logic unit, the registers, the caches, primary storage, secondary storage, and various output devices. The arithmetic-logic unit (ALU) performs the mathematic calculations and makes logical comparisons. The regis-ters are high-speed storage areas that store very small amounts of data and instructions for short periods.

How the CPU WorksIn the CPU, inputs enter and are stored until they are needed. At that point, they are retrieved and processed, and the output is stored and then delivered somewhere. Figure TG 1.3 illus-trates this process, which works as follows:

• The inputs consist of data and brief instructions about what to do with the data. These instructions come into the CPU from random access memory (RAM). Data might be entered by the user through the keyboard, for example, or read from a data fi le in another part of the computer. The inputs are stored in registers until they are sent to the next step in the processing.

FIGURE TG 1.2 Parts of a microprocessor.

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FIGURE TG 1.3 How the CPU works.



• Data and instructions travel in the chip via electrical pathways called buses. The size of the bus—analogous to the width of a highway—determines how much information can fl ow at any time.

• The control unit directs the fl ow of data and instructions within the chip.• The ALU receives the data and instructions from the registers and makes the desired com-

putation. These data and instructions have been translated into binary form—that is, only 0s and 1s. A “0” or a “1” is called a bit. The CPU can process only binary data. All types of data, such as letters, decimal numbers, photographs, music, and so on, can be converted to a binary representation, which can then be processed by the CPU.

• The data in their original form and the instructions are sent to storage registers and then are sent back to a storage place outside the chip, such as the computer’s hard drive. Mean-while, the transformed data go to another register and then on to other parts of the com-puter (to the monitor for display or to storage, for example).

Intel offers excellent demonstrations of how CPUs work: Search the web for “Intel” with “Explore the Curriculum” to fi nd their demos. This cycle of processing, known as a machine instruction cycle, occurs billions of times per second.

Advances in Microprocessor DesignInnovations in chip designs are coming at a faster and faster rate, as described by Moore’s law. In 1965, Gordon Moore, a cofounder of Intel Corporation, predicted that microprocessor com-plexity would double approximately every 2 years. His prediction has been amazingly accurate.

The advances predicted from Moore’s law arise mainly from the following changes:

• Producing increasingly miniaturized transistors.• Placing multiple processors on a single chip. Chips with more than one processor are

called multicore chips. For example, the Cell chip, produced by a consortium of Sony, Toshiba, and IBM, contains nine processors. Computers using the Cell chip display very rich graphics. The chip is also used in TV sets and home theaters that can download and show large numbers of high-defi nition programs. Intel (www.intel.com) and AMD (www.amd.com) offer multicore chips.

• In April 2012, Intel launched its next-generation chips, which employ a three-dimensional (3D) design. The 3D chips require less power than Intel’s current chips while improving performance. These chips enhance the performance of all computers. However, they are particularly valuable in handheld devices, because they extend the device’s battery life.

In addition to increased speeds and performance, Moore’s law has had an impact on costs, as you can see in Table TG 1.3.

Computer MemoryThe amount and type of memory that a computer possesses has a great deal to do with its gen-eral utility. A computer’s memory also determines the types of programs that the computer can run, the work it can perform, its speed, and its cost. There are two basic categories of computer memory. The fi rst is primary storage. It is called “primary” because it stores small amounts of data and information that the CPU will use immediately. The second category is secondary storage, which stores much larger amounts of data and information (an entire software pro-gram, for example) for extended periods.

Year Chip RAM Hard Drive Monitor Cost

1997 Pentium II 64 megabytes 4 gigabytes 17-inch $4,000

2007 Dual-core 1 gigabyte 250 gigabytes 19-inch $1,700

2013 Quad-core 16 gigabytes 2 terabytes 27-inch $1,700

Table

TG 1.3Comparison of Personal Computer Components and Cost over Time



Memory Capacity As you have seen, CPUs process only binary units—0s and 1s—which are translated through computer languages into bits. A particular combination of bits repre-sents a certain alphanumeric character or a simple mathematical operation. Eight bits are needed to represent any one of these characters. This 8-bit string is known as a byte. The stor-age capacity of a computer is measured in bytes. Bits typically are used as units of measure only for telecommunications capacity, as in how many million bits per second can be sent through a particular medium.

The hierarchy of terms used to describe memory capacity is as follows:

• Kilobyte. Kilo means “one thousand,” so a kilobyte (KB) is approximately 1,000 bytes. Actually, a kilobyte is 1,024 bytes. Computer designers fi nd it convenient to work with powers of 2: 1,024 is 2 to the 10th power, and 1,024 is close enough to 1,000 that for kilobyte people use the stan-dard prefi x kilo, which means exactly 1,000 in familiar units such as the kilogram or kilometer.

• Megabyte. Mega means “one million,” so a megabyte (MB) is approximately 1 million bytes. Most personal computers have hundreds of megabytes of RAM memory.

• Gigabyte. Giga means “one billion,” so a gigabyte (GB) is approximately 1 billion bytes.• Terabyte. A terabyte is approximately 1 trillion bytes. The storage capacity of modern per-

sonal computers can be several terabytes.• Petabyte. A petabyte is approximately 1,000 terabytes.• Exabyte. An exabyte is approximately 1,000 petabytes.• Zettabyte. A zettabyte is approximately 1,000 exabytes.

To get a feel for these amounts, consider the following example: If your computer has one terabyte of storage capacity on its hard drive (a type of secondary storage), it can store approxi-mately 1 trillion bytes of data. If the average page of text contains about 2,000 bytes, then your hard drive could store approximately 10 percent of all the print collections of the Library of Congress. That same terabyte can store 70 hours of standard-defi nition compressed video.

Primary Storage. Primary storage, or main memory, as it is sometimes called, stores three types of information for very brief periods of time: (1) data to be processed by the CPU, (2) instructions for the CPU as to how to process the data, and (3) operating system programs that manage various aspects of the computer’s operation. Primary storage takes place in chips mounted on the computer’s main circuit board, called the motherboard. These chips are located as close as physically possible to the CPU chip. As with the CPU, all the data and instructions in primary storage have been translated into binary code.

The four main types of primary storage are (1) register, (2) cache memory, (3) random access memory (RAM), and (4) read-only memory (ROM). You learn about each type of pri-mary storage next.

Registers are part of the CPU. They have the least capacity, storing extremely limited amounts of instructions and data only immediately before and after processing.

Cache memory is a type of high-speed memory that enables the computer to temporarily store blocks of data that are used more often and that a processor can access more rapidly than main memory (RAM). Cache memory is physically located closer to the CPU than RAM. Blocks that are used less often remain in RAM until they are transferred to cache; blocks used infrequently remain in secondary storage. Cache memory is faster than RAM because the instructions travel a shorter distance to the CPU.

Random access memory (RAM) is the part of primary storage that holds a software program and small amounts of data for processing. When you start most software programs (such as Microsoft Word) on your computer, the entire program is brought from secondary storage into RAM. As you use the program, small parts of the program’s instructions and data are sent into the registers and then to the CPU. Compared with the registers, RAM stores more information and is located farther away from the CPU. However, compared with secondary storage, RAM stores less information and is much closer to the CPU.

RAM is temporary and, in most cases, volatile—that is, RAM chips lose their contents if the current is lost or turned off, as from a power surge, brownout, or electrical noise generated by lightning or nearby machines.



Most of us have lost data at one time or another due to a computer “crash” or a power failure. What is usually lost is whatever is in RAM, cache, or the registers at the time, because these types of memory are volatile. Therefore, you need greater security when you are storing certain types of critical data or instructions. Cautious computer users frequently save data to nonvola-tile memory (secondary storage). In addition, most modern software applications have autosave functions. Programs stored in secondary storage, even though they are temporarily copied into RAM when they are being used, remain intact because only the copy is lost, not the original.

Read-only memory (ROM) is the place—actually, a type of chip—where certain critical instructions are safeguarded. ROM is nonvolatile, so it retains these instructions when the power to the computer is turned off. The read-only designation means that these instructions can only be read by the computer and cannot be changed by the user. An example of ROM is the instructions needed to start or “boot” the computer after it has been shut off.

Secondary Storage. Secondary storage is designed to store very large amounts of data for extended periods. Secondary storage has the following characteristics:

• It is nonvolatile. • It takes more time to retrieve data from it than from RAM.• It is cheaper than primary storage (see Figure TG 1.4).• It can utilize a variety of media, each with its own technology, as you see next.

One secondary storage medium, magnetic tape, is kept on a large open reel or in a smaller cartridge or cassette. Although this is an old technology, it remains popular because it is the cheapest storage medium, and it can handle enormous amounts of data. As a result, many organizations (e.g., the U.S. government Social Security Administration) use magnetic tape for archival storage. The downside is that it is the slowest method for retrieving data because all the data are placed on the tape sequentially. Sequential access means that the system might have to run through the majority of the tape before it comes to the desired piece of data.

Magnetic disks (or hard drives or fi xed disk drives) are the most commonly used mass storage devices because of their low cost, high speed, and large storage capacity. Hard disk drives read from, and write to, stacks of rotating (at up to 15,000 rpm) magnetic disk platters mounted in rigid enclosures and sealed against environmental and atmospheric contamina-tion (see Figure TG 1.5). These disks are permanently mounted in a unit that may be internal or external to the computer.

Solid state drives (SSDs) are data storage devices that serve the same purpose as a hard drive and store data in memory chips. Where hard drives have moving parts, SSDs do not. SSDs use the same interface with the computer’s CPU as hard drives and are therefore a seam-less replacement for hard drives. SSDs offer many advantages over hard drives. They use less power, are silent and faster, and produce about one-third the heat of a hard drive. The major disadvantage of SSDs is that they cost more than hard drives.

Unlike magnetic media, optical storage devices do not store data via magnetism. Rather, a laser reads the surface of a refl ective plastic platter. Optical disk drives are slower than magnetic hard drives, but they are less fragile and less susceptible to damage from contamination.

FIGURE TG 1.4 Primary memory compared to secondary storage.



In addition, optical disks can store a great deal of information, both on a routine basis and when combined into storage systems. Types of optical disks include compact disk read-only memory and digital video disk.

Compact disk read-only memory (CD-ROM) storage devices feature high capacity, low cost, and high durability. However, because a CD-ROM is a read-only medium, it cannot be written on. CD-R can be written to, but once this is done, what was written on it cannot be changed later. That is, CD-R is writeable, which CD-ROM is not, but it is not rewriteable, which CD-RW (compact disk, rewritable) is. There are applications where not being rewriteable is a plus, because it prevents some types of accidental data destruction. CD-RW adds rewritability to the recordable compact disk market.

The digital video disk (DVD) is a 5-inch disk with the capacity to store about 135 minutes of digital video. DVDs can also perform as computer storage disks, providing storage capabili-ties of 17 gigabytes. DVD players can read current CD-ROMs, but current CD-ROM players cannot read DVDs. The access speed of a DVD drive is faster than that of a typical CD-ROM drive.

A dual-layer Blu-ray disc can store 50 gigabytes, almost 3 times the capacity of a dual-layer DVD. Development of Blu-ray technology is ongoing, with 3-layered and 4-layered Blu-ray discs available.

Flash memory devices (or memory cards) are nonvolatile electronic storage devices that contain no moving parts and use 30 times less battery power than hard drives. Flash devices are also smaller and more durable than hard drives. The trade-offs are that fl ash devices store less data than hard drives. Flash devices are used with digital cameras, handheld and laptop computers, telephones, music players, and video game consoles.

One popular fl ash memory device is the thumb drive (also called memory stick, jump drive, or fl ash drive). These devices fi t into Universal Serial Bus (USB) ports on personal computers and other devices, and they can store many gigabytes. Thumb drives have replaced magnetic fl oppy disks for portable storage.

Homiel / iStockphoto © Krzysztof Krzyscin/iStockphoto

FIGURE TG 1.5 Traditional hard drives are less expensive, but solid state drives are faster and are more reliable.



[ Summary ]1. Identify the major hardware components of a computer system.

Modern computer systems have six major components: the central processing unit (CPU), primary storage, secondary storage, input technologies, output technologies, and communications technologies.

2. Discuss the strategic issues that link hardware design to business strategy.Strategic issues linking hardware design to business strategy include: How do organizations keep up with the rapid price/performance advancements in hardware? How often should an organization upgrade its computers and storage systems? How can organizations measure benefi ts gained from price/performance improvements in hardware?

3. Describe the hierarchy of computers according to power and their respective roles.Supercomputers are the most powerful computers, designed to handle the maximum com-putational demands of science and the military. Mainframes, although not as powerful as supercomputers, are powerful enough for large organizations to use for centralized data processing and large databases. Minicomputers are smaller and less-powerful versions of mainframes that are often devoted to managing specifi c subsystems. Desktop personal com-puters (PCs) are the common, well-known personal and business computers. Laptop or notebook computers are small, easily transportable PCs. Tablet computers (or tablets) are complete computers contained entirely in a fl at touch screen that uses a stylus, digital pen, or fi ngertip as an input device instead of a keyboard or mouse.

4. Differentiate the various types of input and output technologies and their uses.Principal human data-entry input technologies include the keyboard, mouse, optical mouse, trackball, touchpad, joystick, touch screen, stylus, and voice-recognition sys-tems. Principal source-data automation input devices are ATMs, POS terminals, barcode

What’s In ITFor Me?

For All Business MajorsThe design of computer hardware has profound impacts for businesspeople. Personal and organizational success can depend on an understanding of hardware design and a commitment to knowing where it is going and what opportunities and challenges hardware innovations will bring. Because these innovations are occurring so rapidly, hardware decisions at both the individual level and at the organizational level are diffi cult.

At the individual level, most people who have a home or offi ce computer system and want to upgrade it, or people who are contemplating their fi rst computer pur-chase, are faced with the decision of when to buy as much as what to buy and at what cost. At the organizational level, these same issues plague IS professionals. However, they are more complex and more costly. Most organizations have many different com-puter systems in place at the same time. Innovations may come to different classes of computers at different times or rates. Therefore, managers must decide when old hardware legacy systems still have a productive role in the organization and when they should be replaced. A legacy system is an old computer system or application that con-tinues to be used, typically because it still functions for the users’ needs, even though newer technology is available.


453Chapter Glossary

scanners, optical mark readers, magnetic ink character readers, optical character readers, sensors, cameras, radio frequency identifi cation, and retinal scanning displays. Common output technologies include various types of monitors, impact and nonimpact printers, plotters, and voice output.

5. Describe the design and functioning of the central processing unit.The CPU is made up of the arithmetic-logic unit (ALU), which performs the calculations; the registers, which store minute amounts of data and instructions immediately before and after processing; and the control unit, which controls the fl ow of information on the micro-processor chip. After processing, the data in their original form and the instructions are sent back to a storage place outside the chip.

6. Discuss the relationships between microprocessor component designs and performance.Microprocessor designs aim to increase processing speed by minimizing the physical dis-tance that the data (as electrical impulses) must travel, increasing the number of transistors on the chip, increasing the number of CPUs on the chip, and using three-dimensional chip architecture.

7. Describe the main types of primary and secondary storage.There are four types of primary storage: registers, cache memory, random access mem-ory (RAM), and read-only memory (ROM). Secondary storage includes magnetic media (tapes; hard drives; and thumb, or fl ash, drives) and optical media (CD-ROM, DVD, and Blu-ray disks).

8. Distinguish between primary and secondary storage along the dimen-sions of speed, cost, and capacity.Primary storage has much less capacity than secondary storage, and it is faster and more expensive per byte stored. It is also located much closer to the CPU. Sequential-access secondary storage media such as magnetic tape are much slower and less expensive than hard drives and optical media.

arithmetic-logic unit (ALU) Portion of the CPU that performs the mathematic calculations and makes logical comparisons.augmented reality A live, direct or indirect, view of a physi-cal, real-world environment whose elements are enhanced by computer-generated sensory input such as sound, video, graphics, or GPS data.binary form The form in which data and instructions can be read by the CPU—only 0s and 1s.bit Short for binary digit (0s and 1s), the only data that a CPU can process.byte An 8-bit string of data, needed to represent any one alphanumeric character or simple mathematical operation.cache memory A type of high-speed memory that enables the computer to temporarily store blocks of data that are used more often and that a processor can access more rapidly than main memory (RAM).central processing unit (CPU) Hardware that performs the actual computation or “number crunching” inside any computer.

control unit Portion of the CPU that controls the fl ow of information.fat clients Desktop computer systems that offer full functionality.fl ash memory devices Nonvolatile electronic storage devices that are compact, are portable, require little power, and con-tain no moving parts.gesture recognition an input method that interprets human gestures, in an attempt for computers to begin to understand human body language.laptop computers (notebook computers) Small, easily trans-portable, lightweight microcomputers.magnetic disks (or hard drives or fi xed disk drives) A form of secondary storage on a magnetized disk divided into tracks and sectors that provide addresses for various pieces of data.magnetic tape A secondary storage medium on a large open reel or in a smaller cartridge or cassette.

[ Chapter Glossary ]



mainframes Relatively large computers used in large enter-prises for extensive computing applications that are accessed by thousands of users.microcomputers The smallest and least expensive category of general-purpose computers; also called micros, personal com-puters, or PCs.microprocessor The CPU, made up of millions of transistors embedded in a circuit on a silicon wafer or chip.minicomputers Relatively small, inexpensive, and compact midrange computers that perform the same functions as main-frame computers, but to a more limited extent.Moore’s law Prediction by Gordon Moore, an Intel cofounder, that microprocessor complexity would double approximately every 2 years.multimedia technology Computer-based integration of text, sound, still images, animation, and digitized full-motion video.netbook A very small, lightweight, low-cost, energy-effi cient, portable computer, typically optimized for Internet-based ser-vices such as Web browsing and e-mailing.notebook computer (see computer)optical storage devices A form of secondary storage in which a laser reads the surface of a refl ective plastic platter.primary storage (also called main memory) High-speed stor-age located directly on the motherboard that stores data to be processed by the CPU, instructions telling the CPU how to process the data, and operating systems programs.random access memory (RAM) The part of primary storage that holds a software program and small amounts of data when they are brought from secondary storage.

read-only memory (ROM) Type of primary storage where certain critical instructions are safeguarded; the storage is nonvolatile and retains the instructions when the power to the computer is turned off.registers High-speed storage areas in the CPU that store very small amounts of data and instructions for short periods.secondary storage Technology that can store very large amounts of data for extended periods.sequential access Data access in which the computer sys-tem must run through data in sequence to locate a particular piece.server Smaller midrange computers that support networks, enabling users to share fi les, software, and other network devices.solid state drives (SSDs) Data storage devices that serve the same purpose as a hard drive and store data in memory chips.supercomputer Computers with the most processing power available; used primarily in scientifi c and military work for computationally demanding tasks on very large data sets.tablet computer (or tablet) A complete computer con-tained entirely in a fl at touch screen that uses a stylus, digital pen, or fi ngertip as an input device instead of a keyboard or mouse.thin-client systems Desktop computer systems that do not offer the full functionality of a PC.thumb drive Storage device that fi ts into the USB port of a personal computer and is used for portable storage.wearable computer A miniature computer worn by a person allowing the user to multitask.

1. What factors affect the speed of a microprocessor?2. If you were the CIO of a fi rm, what factors would you

consider when selecting secondary storage media for your company’s records (fi les)?

3. Given that Moore’s law has proved itself over the past two decades, speculate on what chip capabilities will be in 10 years. What might your desktop PC be able to do?

4. If you were the CIO of a fi rm, how would you explain the workings, benefi ts, and limitations of using thin clients as opposed to fat clients?

5. Where might you fi nd embedded computers at home, at school, and/or at work?

[ Discussion Questions ]

1. Access the Web sites of the major chip manufacturers—for example, Intel (www.intel.com), Motorola (www.motorola.com), and Advanced Micro Devices (www.amd.com)—and obtain the latest information regarding new and planned chips. Compare performance and costs across these vendors. Be sure to take a close look at the various multicore chips.

2. Access “The Journey Inside” on Intel’s Web site at http://www.intel.com/content/www/us/en/education/k12/the-journey-inside.html. Prepare a presentation of each step in the machine instruction cycle.

[ Problem-Solving Activities ]


455Internship Activity

[ Internship Activity ]Retail IndustryIt seems that everyone wants a tablet these days. PCs are on the decline and smart phones and tablets are gaining market share every quarter…in the consumer market. The business market has been slightly slower to move to these mobile devices. For businesses, hardware is not a toy; it is a tool that must serve a purpose to justify the expense!

In the retail industry, tablets allow the sales force to carry product and customer information with them on a call and have much quicker access to information. For Dave Herring of Northwestern Financial, it seems that moving to a tablet would be an easy decision. However, there are many options of lightweight devices (even laptops) that are viable options to tablets.

Please visit the Book Companion Site to receive the full set of instructions and learn how you can help Dave research the options and help him with some decision-making guidance on laptops, tablets, and other mobile devices.


Documents

Technology Guide 1 Hardware