System Software

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.

Starting a Computer

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.

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OPERATING SYSTEMS AND UTILITY PROGRAMS

Describe the two types of software

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.

Understand the start-up process for a personal computer

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.

Describe the term user interface

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.

Explain features common to most operating systems

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.

·         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.

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

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.

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Memory vs. Storage

In general, memory (RAM) is fast, short-term, and volatile. Storage, on the other hand, is slower, long-term, 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.

Storage Media and Devices

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.

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STORAGE

Differentiate between storage and memory

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.

Identify various types of storage media and storage devices

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.

Explain how a floppy disk stores data

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.

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OUTPUT

Define the four categories of output

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.

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INPUT

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.

Describe the two types of input

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.

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The System Unit

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

The CPU

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.

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

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.

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Differentiate between the various types of memory

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.

The system unit contains several types of memory.

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.

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

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.

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. 

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THE COMPONENTS OF THE SYSTEM UNIT

Describe the components in the system unit

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.

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

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.

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

  

Compare and contrast various personal computer processors on the market today

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 low-end 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.

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

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.

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Describe the learning aids available with many software applications

Many software applications and Web sites provide learning aids.

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

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.

System Software

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).

The User Interface

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.

Starting an Application

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:

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

4   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.

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

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Define application software

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.

Understand how system software interacts with application software

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.

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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.

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THE INTERNET AND WORLD WIDE WEB

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.

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Introduction to Computer

Computer Literacy

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.

Computer

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.

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Describe the categories of computers and their uses

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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Discuss the uses of the Internet and the World Wide Web

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.

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Explain the purpose of a network

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.

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Differentiate among the various types of software

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.

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

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

·         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). 

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Explain why a computer is a powerful tool

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.

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