26466689 Introduction to Computers

An Overview of the Computer System

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This lesson includes the following sections:

• The Parts of a Computer System

• Looking Inside the Machine

• Software: Bringing the Machine to Life

The Parts of a Computer System

• What is a Computer?

• Hardware

• Software

• Data

• Users

• A computer can convert data into information that is useful to people.

• A complete computer system includes four distinct parts:

Hardware

Software

Data

User

The Parts of a Computer System- What is a Computer?

A computer is an electronic device used to process data.

• A computer's hardware consists of electronic devices; the parts you can see and touch.

• The term "device" refers to any piece of hardware used by the computer, such as a keyboard, monitor, modem, mouse, etc.

The Parts of a Computer System - Hardware

• Software – also called programs – consists of organized sets of instructions for controlling the computer.

• Some programs exist for the computer's use, to help it manage its own tasks and devices.

• Other programs exist for the user, and enable the computer to perform tasks for you, such as creating documents.

The Parts of a Computer System - Software

• Data consists of raw facts, which the computer can manipulate and process into information that is useful to people.

• Computerized data is digital, meaning that it has been reduced to digits, or numbers. The computer stores and reads all data as numbers.

• Although computers use data in digital form, they convert data into forms that people can understand, such as text, numerals, sounds, and images.

The Parts of a Computer System - Data

Ten differentsymbols inthe decimalsystem

Numbers above 9use more than 1 digit

• People are the computer's operators, or users.

• Some types of computers can operate without much intervention from people, but personal computers are designed specifically for use by people.

The Parts of a Computer System – Users

Looking Inside the Machine

• Types of Hardware

• The CPU

• Memory

• How Memory is Measured

• Input and Output Devices

• Storage Devices

A computer's hardware devices are categorized as follows:

• Processor

• Memory

• Input and output (I/O) devices

• Storage devices

Looking Inside the Machine –Types of Hardware

0100101001101010

011011111000111110000000

Looking Inside the Machine - The CPU

The procedure that transforms raw data into useful information is called processing. This function is divided between the computer's processor and memory.

The processor is also called the central processing unit (CPU). It manages all devices and performs the actual processing of data.

The CPU consists of one or more chips attached to the computer's main circuit board (the motherboard).

• Memory also consists of chips attached to the motherboard.

• Memory holds data and program instructions as the CPU works with them. This memory is called Random Access Memory (RAM).

• The CPU can find any piece of datain RAM, when it needs it for processing.

• RAM is volatile, meaning it holds dataonly when the power is on. When the poweris off, RAM's contents are lost.

Looking Inside the Machine - Memory

• The smallest usable unit of measure for memory is the byte – the amount of memory required to hold one character, like the letter A or the numeral 2.

• Computers work with larger chunks of data, measured in multiple bytes, as shown below:

Unit Approx. Value Actual Value (bytes) (bytes)

Kilobyte (KB) 1,000 1,024 Megabyte (MB) 1,000,000 1,048,576Gigabyte (GB) 1,000,000,000 1,073,741,824Terabyte (TB) 1,000,000,000,000 1,099,511,627,776

Looking Inside the Machine– How Memory is Measured

• Input devices accept data and instructions from the user or from another computer system. The keyboard and mouse are examples of input devices.

• Output devices return processed data back to the user or to another computer system. The printer and monitor are examples.

• Communications devices (such as modems and network interface cards) perform both input and output, allowing computers to share information.

Looking Inside the Machine –Input and Output Devices

• Storage devices hold data not currently being used by the CPU. Data is commonly stored on a magnetic or optical disk. Each type uses a special medium for storing data on its surface.

• A disk drive is a device that reads data from and writes data to a disk. Most new computers feature a floppy disk drive, a hard disk drive, and an optical disk drive.

• The most common optical storage devices are CD-ROM and DVD-ROM drives.

Looking Inside the Machine - Storage Devices

Software: Bringing the Machine to Life

• What is Software?

• System Software

• Application Software

• Software is a set of electronic instructions that tells the computer how to do certain tasks. A set of instructions is often called a program.

• When a computer is using a particular program, it is said to be running or executing the program.

• The two most common types of programs are system software and application software.

Bringing the Machine to Life –What is Software?

• System software exists primarily for the computer itself, to help the computer perform specific functions.

• One major type of system software is the operating system (OS). All computers require an operating system.

• The OS tells the computer how to interact with the user and its own devices.

• Common operating systems include Windows, the Macintosh OS, OS/2, and UNIX .

Bringing the Machine to Life –System Software

• Application software tells the computer how to accomplish tasks the user requires, such as creating a document or editing a graphic image.

• Some important kinds of application software are:

Word processing programs Spreadsheet softwareDatabase management Presentation programsGraphics programs Networking software Web design tools and browsers Internet applicationsCommunications programs UtilitiesEntertainment and education Multimedia authoring

Bringing the Machine to Life - Applications

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• List the four parts of a computer system.

• Identify four types of computer hardware.

• List five units of measure for computer memory and storage.

• Provide two examples of input and output devices.

• Name and describe three types of storage devices.

• Differentiate the two main categories of computer software.

• List four specific types of application software.

The Shapes of Computers Today

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• Supercomputers

• Mainframe Computers

• Minicomputers

• Workstations

• Microcomputers, or Personal Computers

The Shapes of Computers Today- Supercomputers

• Supercomputers are the most powerful computers. They are used for problems requiring complex calculations.

• Because of their size and expense, supercomputers are relatively rare.

• Supercomputers are used by universities, government agencies, and large businesses.

The Shapes of Computers Today- Mainframe Computers

• Mainframe computers can support hundreds or thousands of users, handling massive amounts of input, output, and storage.

• Mainframe computers are used in large organizations where many users need access to shared data and programs.

• Mainframes are also used as e-commerce servers, handling transactions over the Internet.

The Shapes of Computers Today- Minicomputers

• Minicomputers are smaller than mainframes but larger than microcomputers.

• Minicomputers usually have multiple terminals.

• Minicomputers may be used as network servers and Internet servers.

The Shapes of Computers Today –Workstations

• Workstations are powerful single-user computers.

• Workstations are used for tasks that require a great deal of number-crunching power, such as product design and computer animation.

• Workstations are often used as network and Internet servers.

The Shapes of Computers Today –Microcomputers, or Personal Computers

• Microcomputers are more commonly known as personal computers. The term "PC" is applied to IBM-PCs or compatible computers.

• Full-size desktop computers are the most common type of PC.

• Notebook (laptop) computers are used by people who need the power of a desktop system, but also portability.

• Handheld PCs (such as PDAs) lack the power of a desktop or notebook PC, but offer features for users who need limited functions and small size.

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• List the five most common types of computer systems.

• Identify two unique features of supercomputers.

• Describe a typical use for mainframe computers

• Differentiate workstations from personal computers.

• Identify four types of personal computers.

Standard Methodsof Input

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• The Keyboard

• The Mouse

• Variants of the Mouse

• The Standard Keyboard Layout

• Ergonomic Keyboards

• How a Keyboard Works

The Keyboard

• A standard computer keyboard has about 100 keys.

• Most keyboards use the QWERTY layout, named for the first six keys in the top row of letters.

The Keyboard - Standard Keyboard Layout

5. Cursor-movement keys

4. Modifier keys

3. Function keys

2. Numeric keypad

1. Alphanumeric keys

Most keyboards have keys arranged in five groups:

The Keyboard - Standard Keyboard Layout

ACADEMIC RECORDSPassword

ENTER Invalid Password

* * * * *

• Long periods of keyboard use can cause injuries.

• An ergonomically correct keyboard can help you avoid injuries.

• You also can avoid injuries by adopting correct keyboarding practices.

The Keyboard - Ergonomic Keyboards

• The keyboard controller detects the keystroke.

• The controller places a scan code in the keyboard buffer, indicating which key was pressed.

• The keyboard sends the computer an interrupt request, telling the CPU to accept the keystroke.

When you press a key:

The Keyboard - How a Keyboard Works

The Mouse

• What is a Mouse?

• Mouse Techniques

The Mouse - What is a Mouse?

• The mouse is a pointing device. You use it to move a graphical pointer on the screen.

• The mouse can be used to issue commands, draw, and perform other types of input tasks.

The Mouse - Mouse Techniques

1. Pointing; Move the mouse to move the on-screen pointer.

2. Clicking; Press and release the left mouse buttononce.

3. Double-clicking; Press and release the left mousebutton twice.

4. Dragging; Hold down the left mouse button as youmove the pointer.

5. Right-clicking; Press and release the right mouse button.

Using the mouse involves five techniques:

Variants of the Mouse

• Trackballs

• Trackpads

• Integrated Pointed Devices

Variants of the Mouse - Trackballs

• A trackball is like a mouse turned upside-down.

• Use your thumb to move the exposed ball and your fingers to press the buttons.

Many styles of trackball are available.

Variants of the Mouse - Trackpads

• A trackpad is a touch-sensitive pad that provides the same functionality as a mouse.

• To use a trackpad, you glide your finger across its surface.

• Trackpads provide a set of buttons that function like mouse buttons.

Variants of the Mouse-Integrated Pointing Devices

• An integrated pointing device is a small joystick built into the keyboard.

• To use an integrated pointing device, you move the joystick.

• These devices provide a set of buttons that function like mouse buttons

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• Identify the five key groups on a standard computer keyboard.

• Describe the purpose of a mouse and the role it plays in computing.

• Identify the five essential techniques for using a mouse.

• Identify three common variants of the mouse.

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Alternative MethodsOf Input


• Devices for the Hand

• Optical Input Devices

• Audio-Visual (Multimedia) Input Devices

Alternative Input Devices –Devices for the Hand

• Pens

• Touch Screens

• Game Controllers

Devices for the Hand - Pens

• With a pen-based system, you use an electronic pen to write on the screen and choose commands.

• Pens are common input devices for handheld computers, like “personal digital assistants (PDAs).”

• Pens are handy for making notes or selecting commands, not for inputting a lot of text.

The user can point, tap, draw and write on the

computer’s screen with a pen.

Devices for the Hand - Touch Screens

• Touch-screen systems accept input directly through the monitor.

• Touch screens use sensors to detect the touch of a finger. They are useful where environmental conditions prohibit the use of a keyboard or mouse.

• Touch-screen systems are useful for selecting options from menus.

Devices for the Hand - Game Controllers

• The two primary types of game controllers are joysticks and game pads.

• Game pads usually provide controls for each hand.

• Joysticks are popular for flight simulator and driving games.

Alternative Input Devices –Optical Input Devices

• Bar Code Readers

• Image Scanners and OCR

Optical Input Devices - Bar Code Readers

• Bar code readers can read bar codes—patterns of printed bars.

• The reader emits light, which reflects off the bar code and into a detector in the reader. The detector translates the code into numbers.

• Flatbed bar code readers are commonly found in supermarkets. Courier services often use handheld readers.

Bar code readers commonly track

sales in retail stores

Optical Input Devices –Image Scanners and OCR

• Image scanners digitize printed images for storage andmanipulation in a computer.

• A scanner shines light onto the image and interprets the reflection.

• Optical character recognition (OCR) software translates scanned text into editable electronic documents.

Light source, lensand diode array

Documentbeing

scanned

Convertsdiode signalsto numbers

To computer

Alternative Input Devices –Audio-Visual (Multimedia) Input Devices

• Microphones and Speech Recognition

• Video Input

Audio-Visual (Multimedia) Input Devices -Microphones and Speech Recognition

• Microphones can accept auditory input. A microphone requires a sound card in the PC.

• A sound card can digitize analog sound signals, and convert digital sound signals to analog form.

• With speech recognition software, you can use your microphone to dictate text, navigate programs, and choose commands.

Digital Audio Output[electrical signals] (ex. 11100011) to

computer

Analog Sound Signals

Analog Signals are Digitized

Audio-Visual (Multimedia) Input Devices –Video Input

• PC video cameras digitize full-motion images.

• Digital cameras capture still images.

• These cameras break images into pixels and store data about each pixel.

• Video images may be compressed to use less memory and storage space.

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• List two reasons why some computer users prefer alternative methods of input over a standard keyboard or mouse.

• List three categories of alternative input devices.

• List two type of optical input devices and describe their uses.

• Describe the uses for speech-recognition systems.

• Identify two types of video input devices and their uses.

Monitors and Sound Systems

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• Monitors

• PC Projectors

• Sound Systems

Monitors

• Categories of Monitors

• CRT Monitors

• Flat-Panel Monitors

• Comparing Monitors

• Video Controllers

Monitors - Categories of Monitors

Monitors are categorized by the technology they use:

• Cathode ray tube (CRT) monitors

• Flat-panel displays

And by the way they display colors:

• Monochrome – One color on a black background

• Grayscale – Shades of gray on a white or off-white background

• Color – From 16 to 16 million unique colors

Monitors - CRT Monitors

• In CRT monitors, electrons are fired at phosphor dots on the screen.

• The dots are grouped into pixels, which glow when struck by electrons.

• In color CRTs, each pixel contains a red, green, and blue dot. These glow at varying intensities to produce color images.

Monitors - Flat-Panel Monitors

• Most flat-panel monitors use liquid crystal display (LCD) technology.

• Passive matrix LCD uses a transistor for each row and column of pixels.

• Active matrix LCD uses a transistor for each pixel on the screen.

• Thin-film transistor displays use multiple transistors for each pixel.

Flat-panel monitors take up less desk space.

Monitors - Comparing Monitors

When comparing monitors, consider four features:

• Size

• Resolution

• Refresh rate

• Dot pitch

Comparing Monitors - Size

• A monitor's size is the diagonal measurement of its face, in inches.

• For years, 15" monitors (13"viewing area) were standard.

• Today, 17" monitors (15" viewing area) are common.

• Larger monitors are available, but can be expensive.

The diagonalsize (often 15”)

Comparing Monitors - Resolution

• Resolution is the number of pixels on the screen, expressed as a matrix (such as 600x800).

• A 17" monitor offers resolutions from 640x480 up to 1280x1024.

• The Video Graphics Array (VGA) standard is 640x480. Super VGA (SVGA) monitors provide resolutions of 800x600, 1024x768 or higher.

Resolution (image sharpness) is important.

(Especially for graphics, page layout, and CAD)

Comparing Monitors - Refresh Rate

• Refresh rate is the number of times each second that the electron guns scan the screen's pixels.

• Refresh rate is measured in Hertz (Hz), or cycles per second.

• Look for a refresh rate of 72 Hz or higher. A slower rate may cause eyestrain.

Fast scanning = Quick refresh (less flicker)

Comparing Monitors - Dot Pitch

• Dot pitch is the distance between the phosphor dots that make up a single pixel.

• In color monitors, three dots (red, green, and blue) comprise each pixel.

• Look for a dot pitch no greater than .28 millimeter.

Fine dot pitch = Crisp displays

R + BB + G

R + GR + B + G

Phosphor Dot Color Mixing

Monitors - Video Controllers

• The video controller is an interface between the monitor and the CPU.

• The video controller determines many aspects of a monitor's performance, such as resolution or the number of colors displayed.

• The video controller contains its own on-board processor and memory, called video RAM (VRAM).

VRAM

Graphic intensive applications suchas games require plenty of VRAM.

Video Control Board with Monitor Cable

PC Projectors

• A PC projector connects to a PC and is used to project images on a large screen.

• Many PC projectors provide the same resolutions and color levels as high-quality monitors.

• Digital light processing (DLP) projectors use a microchip containing tiny mirrors to produce very sharp, bright images.

Projected Screen

Sound Systems

• Multimedia PCs come with a sound card, speakers, and a CD-ROM or DVD drive.

• A sound card translates digital signals into analog ones that drive the speakers.

• With the right software, you can use your PC to edit sounds and create special sound effects.

• List the two most commonly used types of computer monitors.

• Explain how a CRT monitor displays images.

• Identify two types of flat-panel monitors and explain their differences.

• List four characteristics you should consider when comparing monitors.

• Explain how a computer outputs sound.

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les s on 6Devices that Output

Hard Copy


• Overview of Printers

• Dot Matrix Printers

• Ink Jet Printers

• Laser Printers

• Snapshot Printers

• Other High-Quality Printers

Overview of Printers

• Categorizing Printers

• Evaluating Printers

Overview of Printers - Categorizing Printers

Printers fall into two categories:

• Impact printers use a device to strike an inked ribbon, pressing ink from the ribbon onto the paper.

• Non-impact printers use different methods to place ink (or another substance) on the page.

Overview of Printers - Evaluating Printers

When evaluating printers, consider four criteria:

• Image quality – Measured in dots per inch (dpi). Most printers produce 300 – 600 dpi.

• Speed – Measured in pages per minute (ppm) or characters per second (cps).

• Initial cost – Consumer printers cost $250 or less, but professional printers can cost thousands of dollars.

• Cost of operation – This refers to the cost of supplies used by the printer.

Dot Matrix Printers

• How Do Dot Matrix Printers Work?

• Performance

Dot Matrix Printers -How Do Dot Matrix Printers Work?

• Dot matrix printers are a common type of impact printer.

• A dot matrix printer's print head contains a cluster of pins. The printer can push the pins out to form patterns in rapid sequence.

• The pins press an inked ribbon against the paper, creating an image.

Dot Matrix Printers - Performance

• Lower-resolution dot matrix printers use nine pins. Higher-resolution models have 24 pins.

• Speed is measured in characters per second (cps). Some dot matrix printers print 500 cps.

Ink Jet Printers

• How Do Ink Jet Printers Work?

• Performance

Ink Jet Printers –How Do Ink Jet Printers Work?

• Ink jet printers are an example of non-impact printers.

• The printer sprays tiny droplets of ink onto the paper.

• Ink jet printers are available for color and black-and-white printing.

Ink Jet Printers - Performance

• Ink jet printers offer speeds of (2 – 4 pages per minute ppm) and resolution (300 – 600 dots per inch dpi), comparable to low-end laser printers.

• Ink jet printers are inexpensive and have low operating costs.

Laser Printers

• How Do Laser Printers Work?

• Performance

Laser Printers –How Do Laser Printers Work?

• Laser printers are non-impact printers.

• They use heat and pressure to bond particles of toner to paper.

• Laser printers are available for color and black-and-white printing.

Laser Printers - Performance

• Laser printers provide resolutions from 300 – 1200 dpi and higher.

• Black-and-white laser printers usually produce 4 –16 ppm.

• Laser printers produce higher-quality print than ink jet printers, but are more expensive.

Snapshot Printers

• Snapshot printers are specialized, small-format printers that print digital photographs.

• Snapshot printers are fairly slow, and can be more expensive to operate

Snapshot printers are popular among digital camera users

Other High-Quality Printers

Print shops and publishers use these printers to create high-quality color images:

• Thermal-wax

• Dye-sublimation

• Fiery

• IRIS

• Plotters

Plotters use mechanical, ink jet, or thermal technologyto create large-format images for architectural or engineering uses.

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• List the three most commonly used types of printers.

• List the four criteria you should consider when evaluating printers.

• Describe how a dot matrix printer creates an image on a page.

• Explain the process by which a laser printer operates.

• List five types of high-quality printing devices commonly used in business.

Transforming Datainto Information

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• How Computers Represent Data

• How Computers Process Data

• Factors Affecting Processing Speed

• Extending the Processor's Power to Other Devices

• Binary Numbers

• The Binary Number System

• Bits and Bytes

• Text Codes

How Computers Represent Data

How Computers Represent Data– Binary Numbers

• Computer processing is performed by transistors, which are switches with only two possible states: on and off.

• All computer data is converted to a series of binary numbers– 1 and 0. For example, you see a sentence as a collection of letters, but the computer sees each letter as a collection of 1s and 0s.

• If a transistor is assigned a value of 1, it is on. If it has a value of 0, it is off. A computer's transistors can be switched on and off millions of times each second.

Ten differentsymbols inthe decimalsystem

Numbers above 9use more than 1 digit

0011

113102

101010011000111110101100

Base 2

45

109876

Base 10

• To convert data into strings of numbers, computers use the binary number system.

• Humans use the decimal system (“deci” stands for “ten”).

• The binary number system works the same way as the decimal system, but has only two available symbols (0 and 1) rather than ten (0, 1, 2, 3, 4, 5, 6, 7, 8, and 9).

The Binary Number System

• A single unit of data is called a bit, having a value of 1 or 0.

• Computers work with collections of bits, grouping them to represent larger pieces of data, such as letters of the alphabet.

• Eight bits make up one byte. A byte is the amount of memory needed to store one alphanumeric character.

• With one byte, the computer can represent one of 256 different symbols or characters.

.

How Computers Represent Data - Bits and Bytes

1 0 1 1 0 0 1 01 0 0 1 0 0 1 01 0 0 1 0 0 1 11 1 1 1 1 1 1 1

• A text code is a system that uses binary numbers (1s and 0s) to represent characters understood by humans (letters and numerals).

• An early text code system, called EBCDIC, uses eight-bit codes, but is used primarily in older mainframe systems.

• In the most common text-code set, ASCII, each character consists of eight bits (one byte) of data. ASCII is used in nearly all personal computers.

• In the Unicode text-code set, each character consists of 16 bits (two bytes) of data.

How Computers Represent Data - Text Codes

000110000100110001

300110011200110010

EDCBA54

Character

0011010000110101

0100010101000100010000110100001001000001

Code

Examples from theASCII Text Code

Where Processing Occurs:

• The Control Unit

• The Arithmetic Logic Unit

• Machine Cycles

• The Role of Memory in Processing

• Types of RAM

How Computers Process Data

• Processing takes place in the PC's central processing unit (CPU).

• The system's memory also plays a crucial role in processing data.

• Both the CPU and memory are attached to the system's motherboard, which connects all the computer's devices together, enabling them to communicate.

How Computers Process Data –Where Processing Occurs

The two main parts of a CPU are the control unit and the arithmetic logic unit (ALU)

• The control unit directs the flow of data through the CPU, and to and from other devices.

• The control unit stores the CPU's microcode, which contains the instructions for all the tasks the CPU can perform.

How Computers Process Data –The Control Unit

• The actual manipulation of data takes place in the ALU.

• The ALU can perform arithmetic and logic operations.

• The ALU is connected to a set of registers—small memory areas in the CPU, which hold data and program instructions while they are being processed.

How Computers Process Data –The Arithmetic Logic Unit

LogicalOperations

≤, ≤ less than or equal to,not less than or equal to

^ Raise by a power

≥, ≥ greater than or equal to,not greater than or equal to

÷ Divide

<, < less than, not less thanx Multiply

>, > greater than, not greater than− Subtract

=, ≠ equal to, not equal to+ Add

Arithmetic Operations

ALU Operations List

• The CPU follows a set of steps-called a machine cycle-for each instruction it carries out.

• By using a technique called pipelining, many CPUs can process more than one instruction at a time.

• The machine cycle includes two smaller cycles:

During the instruction cycle, the CPU "fetches" a command or data from memory and "decodes" it for the CPU.

During the execution cycle, the CPU carries out the instruction, and may store the instruction's result in memory.

How Computers Process Data –Machine Cycles

• RAM stores data and program code needed by the CPU. The contents of RAM change rapidly and often.

• Read-only memory (ROM) is nonvolatile (or permanent). It holds instructions that run the computer when the power is first turned on.

• The CPU accesses each location in memory by using a unique number, called the memory address.

How Computers Process Data –The Role of Memory

There are two basic types of RAM: static and dynamic

• Dynamic RAM (DRAM) chips must be rechargedwith electricity very frequently, or they will lose theircontents.

• Static RAM (SRAM) does not need to be rechargedas often as DRAM, and can hold its contents longer.

Another type of RAM, called flash memory, can store its contents after power is turned off. Flash memory is used in digital cameras to store pictures.

How Computers Process Data -Types of RAM

• Registers

• RAM

• The System Clock

• The Bus

• Cache Memory

Factors Affecting Processing Speed

• The CPU contains a number of small memory areas, called registers, which store data and instructions while the CPU processes them.

• The size of the registers (also called word size) determines the amount of data with which the computer can work at a one time.

• Today, most PCs have 32-bit registers, mean the CPU can process four bytes of data at one time. Register sizes are rapidly growing to 64 bits.

Factors Affecting Processing Speed – Registers

• The amount of RAM in a PC has a direct affect on the system's speed.

• The more RAM a PC has, the more program instructions and data can be held in memory, which is faster than storage on disk.

• If a PC does not have enough memory to run a program, it must move data between RAM and the hard disk frequently. This process, called swapping, can greatly slow a PC's performance.

Factors Affecting Processing Speed – RAM

More RAM = Better Performance!

• The computer's system clock sets the pace for the CPU by using a vibrating quartz crystal.

• A single "tick" of the clock is the time required to turn a transistor off and back on. This is called a clock cycle.

• Clock cycles are measured in Hertz (Hz), a measure of cycles per second. If a computer has a clock speed of 300 MHz, then its system clock "ticks" 300 million times every second.

• The faster a PC's clock runs, the more instructions the PC can execute each second.

Factors Affecting Processing Speed –The System Clock

• A bus is a path between the components of a computer. Data and instructions travel along these paths.

• The data bus' width determines how many bits can be transmitted between the CPU and other devices.

• The address bus runs only between the CPU and RAM, and carries nothing but memory addresses for the CPU to use.

• Peripheral devices are connected to the CPU by an expansion bus.

Factors Affecting Processing Speed –The Bus

• Cache memory is high-speed memory that holds the most recent data and instructions that have been loaded by the CPU.

• Cache is located directly on the CPU or between the CPU and RAM, making it faster than normal RAM.

• CPU-resident cache is called Level-1 (L1) cache. External cache is called Level-2 (L2) cache.

• The amount of cache memory has a tremendous impact on the computer's speed.

Factors Affecting Processing Speed –Cache Memory

• Ports

• Expansion Slots and Boards

Extending the Processor's Powerto Other Devices

• External devices—such as those used for input and output—are connected to the system by ports on the back of the computer.

• PCs feature a number of built-in ports, which are ready to accept devices such as a printer, mouse, keyboard, phone line, microphone and speakers, and others.

• Most computers come with a serial port and a parallel port. A serial port transmits one bit of data at a time; a parallel port transmits data one byte at a time.

Extending the Processor's Powerto Other Devices – Ports

• If the PC does not have a port for an external device, you can install an expansion board into one of the empty expansion slots.

• A board provides the correct port for the new device, and connects the device to the CPU by way of the computer's expansion bus.

• Newer bus technologies such as Universal Serial Bus (USB) and IEEE 1394 enable many devices to be connected to one port.

• Small Computer System Interface (SCSI) is an older standard for extending the bus to multiple devices through a single port.

Adding Other Devices –Expansion Slots and Boards

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• List two reasons why computers use the binary number system.

• List the two main parts of the CPU and explain how they work together.

• Explain the difference between RAM and ROM.

• Identify two RAM technologies used in PCs.

• List three hardware factors that affect processing speed.

• Identify four connections used to attach devices to a PC.

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CPUs Used in Personal Computers

This lesson introduces:

• Intel Processors

• AMD Processors

• Cyrix Processors

• Motorola Processors

• RISC Processors

CPUs Used in Personal Computers –Intel Processors

• Since 1978, Intel's processors have evolved from the 8086 and the 8088 to the 80286, 80386, and 80486, to the Pentium family of processors. All are part of the 80x86 line.

• Intel's Pentium family of processors includes the Pentium, Pentium Pro, Pentium with MMX, Pentium II, Pentium III, Celeron, and Xeon processors.

• The earliest Intel processors included only a few thousand transistors. Today's Pentium processors include 9.5 million transistors or more.

Intel’s Pentium III processor

CPUs Used in Personal Computers –AMD Processors

• Advanced Micro Devices (AMD) was long known as a provider of lower-performance processors for use in low-cost computers.

• With its K6 line of processors, AMD challenged Intel's processors in terms of both price and performance.

• With the K6-III processor, AMD broke the 600 MHz barrier, claiming the "fastest processor" title for the first time in IBM-compatible computers.

The AMD K6-III processor

CPUs Used in Personal Computers -Cyrix Processors

• Cyrix began as a specialty chip maker, but eventually began producing microprocessors.

• Cyrix processors are most commonly used in low-price, low-end consumer PCs.

• Cyrix formerly produced the MediaGX processor, and now produces the MII series of processors.

The Cyrix Processor

CPUs Used in Personal Computers –Motorola Processors

• Motorola makes the CPUs used in Macintosh and PowerPC computers.

• Macintosh processors use a different basic structural design (architecture) than IBM-compatible PC processors.

• With the release of the G3 and G4 PowerPC processors, Macintosh computers set new standards for price and performance.

Apple’s G4 computers are based on Motorola processors

CPUs Used in Personal Computers- RISC Processors

• Most PCs are based on complex instruction set computing (CISC) chips which contain large instruction sets.

• Reduced instruction set computing (RISC) processors use smaller instruction sets. This enables them to process more instructions per second than (CISC) chips.

• RISC processors are found in Apple's PowerPC systems, as well as many H/PCs, workstations, minicomputers, and mainframes.

Compaq’s AlphaServer computers are based on

RISC processors

• In parallel processing, multiple processors are used in a single system, enabling them to share processing tasks.

• In a massively parallel processor (MPP) system, many processors are used.

• Some MPP systems utilize thousands of processors simultaneously.

CPUs Used in Personal Computers-Parallel Processing

les s on 8 R ev iew

• Name the three best-known families of CPUs and list their differences.

• List all the processors in Intel’s 80x86 line of processors.

• Identify the key processor families from AMD and Cyrix.

• Differentiate the processors used in Macintosh and IBM-compatible PCs.

• Define the terms CISC and RISC.

• Identify one advantage of using multiple processors in computers.

Types of Storage Devices

les s on 9


• Categorizing Storage Devices

• Magnetic Storage Devices

• Optical Storage Devices

Categorizing Storage Devices

• Storage devices hold data, even when the computer is turned off.

• The physical material that actually holds data is called a storage medium. The surface of a floppy disk is a storage medium.

• The hardware that writes data to or reads data from a storage medium is called a storage device. A floppy disk drive is a storage device.

• The two primary storage technologies are magnetic and optical.

The primary types of magnetic storage are:

• Diskettes (floppy disks)

• Hard disks

• High-capacity floppy disks

• Disk cartridges

• Magnetic tape

The primary types of optical storage are:

• Compact Disk Read-Only Memory (CD-ROM)

• Digital Video Disk Read-Only Memory (DVD-ROM)

• CD-Recordable (CD-R)

• CD-Rewritable (CD-RW)

• PhotoCD

Magnetic Storage Devices

• How Magnetic Storage Works

• Formatting

• Disk Areas

• Diskettes

• Hard Disks

• Disk Capacities

• Other Magnetic Storage Devices

Magnetic Storage Devices- How Magnetic Storage Works

• A magnetic disk's medium contains iron particles, which can be polarized—given a magnetic charge—in one of two directions.

• Each particle's direction represents a 1 (on) or 0 (off), representing each bit of data that the CPU can recognize.

• A disk drive uses read/write heads containing electromagnets to create magnetic charges on the medium.

Random particles(no data stored)

Current flow(write operation)

Organized particles(represent data)

Medium

Write head

As the mediumrotates, the headwrites the data.

Magnetic Storage Devices - Formatting

• Before a magnetic disk can be used, it must be formatted—a process that maps the disk's surface and determines how data will be stored.

• During formatting, the drive creates circular tracks around the disk's surface, then divides each track into sectors.

• The OS organizes sectors into groups, called clusters, then tracks each file's location according to the clusters it occupies.

Formatted Disk

Magnetic Storage Devices - Disk Areas

When a disk is formatted, the OS creates fourareas on its surface:

• Boot sector – stores the master boot record, a small program that runs when you first start (boot) the computer

• File allocation table (FAT) – a log that records each file's location and each sector's status

• Root folder – enables the user to store data on the disk in a logical way

• Data area – the portion of the disk that actually holds data

Magnetic Storage Devices - Diskettes

• Diskette drives, also known as floppy disk drives, read and write to diskettes (called floppy disks or floppies).

• Diskettes are used to transfer files between computers, as a means for distributing software, and as a backup medium.

• Diskettes come in two sizes: 5.25-inch and 3.5-inch.

3.5 inchfloppy

and drive

Magnetic Storage Devices - Hard Disks

• Hard disks use multiple platters, stacked on a spindle. Each platter has two read/write heads, one for each side.

• Hard disks use higher-quality media and a faster rotational speed than diskettes.

• Removable hard disks combine high capacity with the convenience of diskettes.

Read/write heads

Magnetic Storage Devices - Disk Capacities

• Diskettes are available in different capacities, but the most common store 1.44 MB.

• Hard disks store large amounts of data. New PCs feature hard disks with capacities of 10 GB and higher.

Magnetic Storage Devices -Other Magnetic Storage Devices

• High-capacity floppy disks offer capacities up to 250MB and the portability of standard floppy disks.

• Disk cartridges are like small removable hard disks, and can store up to 2 GB.

• Magnetic tape systems offer very slow data access, but provide large capacities and low cost.

Due to long access times, tapedrives are used mainly for backups.

Optical Storage Devices

• How Optical Storage Works

• CD-ROM

• CD-ROM Speeds and Uses

• DVD-ROM

• Other Optical Storage Devices

Optical Storage Devices –How Optical Storage Works

• An optical disk is a high-capacity storage medium. An optical drive uses reflected light to read data.

• To store data, the disk's metal surface is covered with tiny dents (pits) and flat spots (lands), which cause light to be reflected differently.

• When an optical drive shines light into a pit, the light cannot be reflected back. This represents a bit value of 0 (off). A land reflects light back to its source, representing a bit value of 1 (on).

1 0

Optical Storage Devices –CD-ROM

• In PCs, the most commonly usedoptical storage technology is calledCompact Disk Read-Only Memory (CD-ROM).

• A standard CD-ROM disk can store up to 650 MB of data, or about 70 minutes of audio.

• Once data is written to a standard CD-ROM disk, the data cannot be altered or overwritten.

Optical Storage Devices –CD-ROM Speeds and Uses

• Early CD-ROM drives were called single speed, and read data at a rate of 150 KBps. (Hard disks transfer data at rates of 5 – 15 MBps).

• CD-ROM drives now can transfer data at speeds of up to 7800 KBps. Data transfer speeds are getting faster.

• CD-ROM is typically used to store software programs. CDs can store audio and video data, as well as text and program instructions.

Optical Storage Devices - DVD-ROM

• A variation of CD-ROM is called Digital Video Disk Read-Only Memory (DVD-ROM), and is being used in place of CD-ROM in many newer PCs.

• Standard DVD disks store up to 9.4 GB of data—enough to store an entire movie. Dual-layer DVD disks can store up to 17 GB.

• DVD disks can store so much data because both sides of the disk are used, along with sophisticated data compression technologies.

Optical Storage Devices -Other Optical Storage Devices

• A CD-Recordable (CD-R) drive lets you record your own CDs, but data cannot be overwritten once it is recorded to the disk.

• A CD-Rewritable (CD-RW) drive lets you record a CD, then write new data over the already recorded data.

• PhotoCD technology is used to store digital photographs.

les s on 9 R ev iew

• List four types of magnetic and four types of optical storage devices.

• Identify three common uses for floppy disks.

• Name the four areas created on a magnetic disk during formatting.

• Explain how data is stored on the surface of magnetic and optical disks.

• List three variations on optical disk technology.

Measuring Drive Performance

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• Average Access Time

• File Compression

• Data-Transfer Rate

• Drive-Interface Standards

Average Access Time

• In storage devices, average access time (or seek time) is the time required for a read/write head to move to a spot on the storage medium.

• For storage devices, access time is measured in milliseconds (ms), or thousandths of a second. In memory, access time is measured in nanoseconds (ns), or one-billionths of a second.

• Diskette drives offer an average access time of 100 ms. Hard drives are faster, usually between 6 – 12 ms.

20-500 sTape drives80-800 msCD ROM drives6-12 msHard disk drives55-250 nsRead only memory (ROM)50-70 nsDynamic RAM (DRAM)5-15 nsStatic RAM (SRAM)

Typical Access TimeDevice

Typical Access Times for Memory and Storage Devices

File Compression• File compression technology shrinks files so they take

up less disk space.

• Using a compression utility, you can shrink multiple files into a single archive file.

• Utilities such as Windows' DriveSpace enable you to compress the entire contents of your hard disk.

My archive

Data-Transfer Rate

• Data-transfer rate (or throughput) measures the time required for data to travel from one device to another.

• If a device transfers 45,000 bytes per second, its data-transfer rate is 45 KBps.

• Hard disks offer the fastest data-transfer rates of any storage device.

Hard Disk Fragmentation

One file can end up fragmented(scattered) over the disk surface.

Hard Disk Fragmentation

This results in multiple head accesseswhich degrades performance.

Drive-Interface Standards

• All PCs use a disk controller as an interface between a disk drive and the CPU. The two most common interface standards are EIDE and SCSI.

• EIDE has evolved over the years and has several variants, all of which have different names.

• SCSI is a faster, more flexible drive-interface standard found in high-performance computers.

les s on 10 R ev iew

• Define average access time and explain how it is measured.

• Explain why file compression is a factor in drive performance.

• Define data transfer rate and describe how it is measured.

• Identify two drive interface standards.

les s on 11

Operating System Basics


• The User Interface

• Running Programs

• Managing Files

• Managing Hardware

• Utility Software

• Graphical User Interfaces (GUIs)

• GUI Tools

• Applications and the Interface

• Menus

• Dialog Boxes

• Command-Line Interfaces

The User Interface

• Most modern operating systems, like Windows and the Macintosh OS, provide a graphical user interface (GUI).

• A GUI lets you control the system by using a mouse to click graphical objects on screen.

• A GUI is based on the desktop metaphor. Graphical objects appear on a background (the desktop), representing resources you can use.

The User Interface- Graphical User Interfaces (GUIs)

Icons

Start menuStart buttonTaskbar

Desktop

Dialog box

Programrunning ina window

Window control buttons

• Icons are pictures that represent computer resources, such as printers, documents, and programs.

• You double-click an icon to choose (activate) it, for instance, to launch a program.

• The Windows operating system offers two unique tools, called the taskbar and Start button. These help you run and manage programs.

The User Interface - GUI Tools

Or, icons can bedouble-clicked tolaunch programs.

The Windows startbutton can be usedto launch programs.

• Applications designed to run under one operating system use similar interface elements.

• Under an OS such as Windows, you see a familiar interface no matter what programs you use.

• In a GUI, each program opens and runs in a separate window—a frame that presents the program and its documents.

• In a GUI, you can run multiple programs at once, each in a separate window. The application in use is said to be the active window.

The User Interface –Applications and the Interface

Titlebar

Menubar

Toolbar

Scroll arrow

Scroll box

Scroll bar

Click the Minimize button to reducethe program to a button on the taskbar.Click the Maximize button to restorethe window to its previous size.

Click the Close button to closethe window altogether.

• GUI-based programs let you issue commands by choosing them from menus.

• A menu groups related commands. For example, the File menu's commands let you open, save, and print document files.

• Menus let you avoid memorizing and typing command names.

• In programs designed for the same GUI, menus and commands are similar from one program to another.

The User Interface - Menus

• A dialog box is a special window that appears when a program or the OS needs more information before completing a task.

• Dialog boxes are so named because they conduct a "dialog" with the user, asking the user to provide more information or make choices.

The User Interface - Dialog Boxes

• Some older operating systems, such as DOS and UNIX, use command-line interfaces.

• In a command-line interface, you type commands at a prompt.

• Under command-line interfaces, individual applications do not need to look or function the same way, so different programs can look very different

.

The User Interface - Command-Line Interfaces

The DOS Prompt is not seen much these days!

• Basic Services

• Sharing Information

• Multitasking

Running Programs

• The operating system manages all the other programs that run on the PC.

• The operating system provides services to programs and the user, including file management, memory management, and printing

• To provide services to programs, the OS makes system calls—requesting other hardware and software resources to perform tasks.

Running Programs - Basic Services

• Some operating systems, such as Windows, enable programs to share information.

• You can create data in one program and use it again in other programs without re-creating it.

• Windows provides the Clipboard, a special area that stores data cut or copied from one document, so you can re-use it elsewhere.

Running Programs - Sharing Information

1

2

3

Information is clippedfrom one application (Excel)

Using the clipboard Viewer toexamine the information

Pasting the informationinto another application (WordPro)

• Multitasking is the capability of running multiple processes simultaneously.

• A multitasking OS lets you run multiple programs at the same time.

• Through multitasking, you can do several chores at one time, such as printing a document while downloading a file from the Internet.

• There are two types of multitasking: cooperative and preemptive.

Running Programs - Multitasking

• The operating system keeps track of all the files on each disk.

• Users can make file management easier by creating a hierarchical file system that includes folders and subfolders arranged in a logical order.

Managing Files

• The OS uses interrupt requests (IRQs) to maintain organized communication with the CPU and other pieces of hardware.

• Each hardware device is controlled by a piece of software, called a driver, which allows the OS to activate and use the device.

• The operating system provides the software necessary to link computers and form a network.

Managing Hardware

A utility is a program that performs a task that is not typically handled by the operating system.

Some utilities enhance the operating system's functionality.

Some of the major categories of utilities include:• File defragmentation• Data compression• Backup• Antivirus• Screen savers

Utility Software

les s on 11 r ev iew

• Name four components found in most graphical user interfaces.

• Describe the operating system’s role in running software programs.

• Explain how the OS enables users to manage files.

• List three hardware management tasks performed by an OS.

• Name five types of utility software.

PC Operating Systems in Review

les s on 12

• UNIX• DOS• The Macintosh Operating System• Windows 3.x• OS/2 Warp• Windows NT• Windows 95 and 98• Linux

• Windows 2000


• UNIX is the oldest operating system used on PCs.

• UNIX was the first multi-user, multiprocessor, multitasking operating system available for use on PCs.

• Most versions of UNIX use a command-line interface, but some versions offer a GUI.

UNIX

• DOS dominated the operating system market during the 1980s.

• DOS is a single-user OS that supports only 640 KB of memory.

• DOS features a command-line interface, and does not support multitasking or multiprocessing.

• Because DOS provides no interface restrictions, DOS applications can look and function differently.

DOS

• The Macintosh OS supports the graphical nature of the Macintosh computer.

• The Mac OS brought the first truly graphical user interface to consumers.

• The Mac OS also brought interface conformity to the desktop. All applications running under the Mac OS, therefore, provided the same "look and feel" to the user.

The Macintosh Operating System

• Windows 3.0, 3.1, and 3.11 are called the Windows 3.x family.

• Windows 3.x brought a GUI and multitasking capabilities to PCs running DOS.

• Windows 3.x is an operating environment because it ran on top of DOS, which was the actual OS.

Windows 3.x

• OS/2 Warp was the first true GUI-based operating system for Intel-based PCs.

• OS/2 is a multitasking OS that provides support for networking and multiple users.

• It was the first PC OS to feature built-in speech recognition capabilities.

OS/2 Warp

• Microsoft's Windows NT was meant as a replacement for DOS, but was too resource- intensive to work on most PCs at the time of its release.

• Microsoft issued two versions of Windows NT—Windows NT Workstation and Windows NT Server.

• NT is a very powerful and robust OS, resistant to system crashes.

Windows NT

• Windows 95 was Microsoft's first true GUI-based, 32-bit operating system for Intel PCs.

• Windows 95 supports multitasking and can run older DOS and Windows 3.x programs.

• Windows 98's features include advanced Internet capabilities, an improved user interface, and enhanced file system performance, among others.

Windows 95 and 98

• Linux is a recently developed version of UNIX, which is available for free or at a very low cost from various sources.

• Linux is a very powerful 32-bit OS that supports multitasking, multiple users, networking, and virtually any application.

• Linux can run on nearly any type of computer.

• Because of its power and openness, Linux is attracting many users, including students, teachers, Internet service providers, and others.

Linux

• Windows 2000 features the same interface and features of Windows 98, with the file system, networking, power, and stability of Windows NT.

• Several versions of Windows 2000 are available, each targeting a specific user or computing environment, from home PCs to large enterprise networks.

Windows 2000


• List all the major PC operating systems.

• Identify some of the limitations of DOS.

• List two features that made the Macintosh OS popular.

• Differentiate between the terms operating environment and operating system.

• List the various versions of Windows.

Word Processing and Desktop Publishing

Software

les s on 13

This lesson includes the following sections:• Word Processing Programs and Their Uses

• The Word Processor's Interface

• Entering and Editing Text

• Formatting Text

• Special Features of Word Processing Software

• Desktop Publishing Software

• Converting Documents into World Wide Web Pages

• Word processors provide tools for creating, editing, and formatting text-based documents.

• You can use a word processor to create virtually any type of document, from a simple letter to a complete book.

• A word processor's formatting tools let you create professional-quality documents easily.

Word Processing Programs and Their Uses

Word processors provide tools to produceprofessional looking documents.

• Document area

• Menu bar

• Toolbars

• Rulers

• Scroll Bars

• Status Bar

Most Windows-based word processors offer a similar set of tools, which you use to navigate, edit, and format documents:

The Word Processor's Interface

Menu bar Toolbars

Ruler

Document areaStatus bar

Scroll barScroll boxes

• You create a document by entering text in the document window.

• A blinking insertion point shows you where characters will be placed as you type.

• When you type to the end of a line, the program automatically moves the insertion point to the next line. This feature is called word wrap.

Entering and Editing Text –Adding Text to a Document

Entering and Editing Text –Editing a Document

• The Backspace and Delete keys let you erase one or more characters.

• Overtype mode lets you type over previously entered text.

• AutoCorrect can automatically correct spelling and typing errors.

• Undo and Redo let you reverse the effect of a previous action.

Making changes to an existing document is called editing. Tools are provided for erasing and retyping text quickly:

• Word processors let you work with entire blocks of text. You can format, move, copy, or delete a block.

• To work with a block of text, you must first select it, using one of many selection options. Selected text is highlighted on the screen.

• When you are finished working with selected text, you can deselect it.

Entering and Editing Text - Selecting Text

Here, a selected block of text is deleted.

Electrical.wpd

• Character formats

• Paragraph formats

• Document formats

Formatting a document means controlling its appearance.

Formats fall into three broad categories:

Formatting Text

• You can use multiple fonts in a document, such as Arial or Times.

• Word processors let you apply different sizes –measured in points – to the text in a document.

• You can apply type styles to your text, such as bold, italic, and underline, among others.

Formatting Text - Character Formats

• In a word processor, you create a new paragraph whenever you press Enter. You can format each paragraph in a different way.

• You can set the amount of blank space between lines in a paragraph and between paragraphs in a document.

• To align a paragraph, you set the space between its edges and the page's margins. You can also indent a paragraph's first line.

• Borders and shading create special effects for paragraphs.

Formatting Text - Paragraph Formats

• Margins are the amount of blank space between the edges of the text and the edges of the page.

• Word processors let you print documents on different size paper, in portrait or landscape orientation.

• Headers and footers are commonly used in long documents, to provide continuing information along the top or bottom of the pages.

Formatting Text - Document Formats

As shown on the next graphic, documents can be divided into sections to give each a unique format.

Heading section

Three-column format section

• Language tools

• Tables

• Mail Merge

• Support for graphics and sounds

• Templates

Today's word processors provide a variety of specialized tools, including:

Special Features of Word Processing Software

• Spell checkers, which can help you find and correct misspelled words.

• Grammar checkers, which help your document conform to accepted grammatical rules.

• Thesauri, which can help you make the best word choices.

Language tools can help you improve the quality of your documents by catching language errors. Language tools include:

Special Features of Word Processing Software - Language Tools

Whoops!

• Tables let you set up rows and columns of information.

• You can format a table in dozens of ways, add headings, and more.

Special Features of Word ProcessingSoftware - Tables

• Mail merge is the process of combining a form letter with contents of an address database.

• Using mail merge, you can create a standard letter and automatically make a copy for each person in your database.

Special Features of Word ProcessingSoftware - Mail Merge

• Word processors allow you to add images to your documents.

• Once you add a graphic to a document, you can select it, move it, resize it, and more.

• You also can add sound files to a document. A sound file appears as an icon; click the icon on screen and the file plays.

Special Features of Word ProcessingSoftware - Support for Graphics and Sounds

Imported graphic

Embedded sound file

• A template is a predesigned document.

• A template simplifies document design. You simply open the document and type your text.

Special Features of Word ProcessingSoftware - Templates

• Desktop publishing (DTP) software is specialized for designing and laying out long documents, such as magazines or books.

• DTP software provides special tools for fine-tuning the appearance of text and graphics in a document.

• DTP software can produce documents that are ready to be sent to a professional printer.

Desktop Publishing Software

• Word processors can create documents in HTML format, ready to be published on the World Wide Web.

• To create an HTML document, create a normal document then save it in HTML format. The word processor inserts all the required HTML tags.

• Many word processors include HTML templates, which let you easily create finished Web pages.

Converting Documents Into World Wide Web Pages

• Identify three basic word processing tools that simplify document editing.

• Explain what is meant by "selecting" parts of a document.

• Identify five special features commonly found in modern word processors.

• Distinguish desktop publishing software from word processing software.

• Describe how word processors can convert normal documents into World Wide Web pages.


SpreadsheetSoftware

les s on 14


• Spreadsheet Programs and Their Uses

• The Spreadsheet's Interface

• Entering Data in a Worksheet

• Editing and Formatting a Worksheet

• Adding Charts

• Analyzing Data in a Spreadsheet

• Spreadsheets provide tools for working with numerical data.

• You can use a spreadsheet program to create budgets, balance sheets, and other types of number-based documents.

• You can display your information in a traditional row-and-column format, or in a chart.

Spreadsheet Programs and Their Uses

Classic row and column format

Report usingcolor and graphics

• In a spreadsheet program, you work in a document called a worksheet. You can collect multiple worksheets into a file called a workbook.

• Most Windows-based word spreadsheets offer a similar set of tools, including a formula bar, where you can enter and edit data.

• Data is displayed in cells. A cell is the intersection of a row and column.

• Each cell has a cell address – the combination of the cell's column letter and row number.

The Spreadsheet's Interface

Menu barTool bars

Column

Row

Status barScroll boxes

CellFormula bar

• Labels--text or numbers not used in calculations.

• Values--numbers that can be used in calculations.

• Dates--a necessary part of most worksheets.

• Formulas--commands to perform calculations based on numbers or formulas.

You enter four types of data in a worksheet's cells:

Entering Data in a Worksheet- Types of Data

• If a formula uses a value in another cell, the formula contains a cell reference, or the address of the referred cell.

• Formulas can refer to entire ranges (or blocks) of contiguous cells as well as individual cells.

• A function is a predefined formula, which the spreadsheet provides to perform a specific type of calculation. You provide arguments that tell the function what data to use.

Entering Data in a Worksheet- Formulas and Functions

• Spreadsheets provide many of the same editing and formatting tools found in word processors.

• You can change, copy, move, and delete the data in any cell.

Editing and Formatting a Worksheet

• An absolute cell reference always refers to the same cell even if the formula is moved to a different place.

• If a formula uses a relative cell reference, it automatically dates if (copied or moved), to a different place.

Relative and Absolute Cell References

• A chart is a graphical representation of the data in a worksheet.

• Spreadsheets provide tools that make it easy to create a chart from worksheet data.

• You can use many different types of charts, and apply many effects to a chart, to present your data in the most appropriate way.

Adding Charts

• What-if analysis, which lets you test scenarios to see how each affects the result.

• Goal seeking, which finds values that make the result meet your specifications.

• Sorting, which lets you arrange the worksheet's data in various ways.

Three commonly used data-analysis tools are:

Analyzing Data in a Spreadsheet

• Define and differentiate the terms worksheet and spreadsheet.

• Identify four types of data that can be entered in a worksheet.

• Explain how cell addresses are used in spreadsheet programs.

• Explain what a formula is and how formulas can be used in spreadsheet programs.

• List three types of analytical tools commonly found in spreadsheets.


PresentationPrograms

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• Presentation Program Basics

• Integrating Multiple Data Sources

• Presenting Slide Shows

• Presentation Programs and Their Uses

• The Presentation Program's Interface

• Creating a Presentation

• Formatting Slides

• Special Features of Presentation Programs

Presentation Program Basics

• Presentation programs are used to create slides–single-screen images that contain text, graphics, charts, and more.

• A collection of slides is called a presentation.

• A presentation program lets you create a set of slides and show (present) them to an audience.

Presentation Program Basics -Presentation Programs and Their Uses

Presentation programs provide many of the same editing and formatting tools found in word processors and other common applications.

Presentation Program Basics -The Presentation Program's Interface

Title barMenu barTool bars

Document area

Drawing toolsStatus bar

• To create a presentation, you can select a predesigned template to create a common look for the slides.

• Individual slide elements appear inside text boxes and frames.

• You can easily add text or graphics to a box or frame, and move or resize it as needed.

.

Presentation Program Basics -Creating a Presentation

To resize a frame or text box, click it, then dragone of its handles.

• Fonts and font sizes

• Colors

• Backgrounds

• Borders

You can format a slide by choosing different:

Presentation Program Basics -Formatting Slides

Gradient fill background

Borders

• Outlining—for contents, arrangement and order.

• Annotations—notes to individual slides.

• Animation—moving transitions to parts of a slide.

• Sound and video—audio or multimedia enhancement.

• Embedded objects—WWW links.

• HTML conversion—presentations on the Web.

Presentation programs provide several special features:

Presentation Program Basics -Special Features

• You can add different media types, such as audio or video files, to a slide.

• If you present your slides from the PC's disk and have the appropriate output devices, you can present multimedia elements in a slide show.

Integrating Multiple Data Sourcesin a Presentation

• You can present them in any order you like.

• You can display slides on the PC's monitor, project them on a screen, or connect the PC to a TV or large monitor.

• You can move from slide to slide manually, or automate the presentation.

You can print slides and present them on a slide or overhead projector.

You also can display slides directly from the PC's disk, with the following advantages:

Presenting Slide Shows

• Identify four interface elements found in most presentation programs.

• Describe the process of creating a presentation.

• Name three media sources that might be used in a multimedia presentation.

• List three ways that slides can be presented from a presentation program.


Database Management Systems and Enterprise

Software

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• Databases and Management Systems

• Working with a Database

• Enterprise Software

• The Difference between Databases and DBMSes

• Database Basics

• DBMSes Basics

Databases and Database Management Systems

• A database is a repository for collections of related data or facts.

• A database management system (DBMS) is a software tool that lets users add, view, and work with the data in a database.

• Large databases and DBMS’ are commonly used by companies, but many productivity applications are built around database concepts.

Databases and Database Management SystemsThe Difference between Databases and DBMSes

The two primary types of databases are flat-file databases (with only one table) and relational databases (with multiple, related tables).

• Fields, which store various pieces of data related to a single entity.

• Records, or collections of fields relating to an entity.

• Tables, which are collections of related records.

Databases use three main structures for organizing data:

Databases and DBMSes - Database Basics

Field

Record

Table

PROFESSIONAL ADDRESS BOOK

• Entering data into the database.

• Sorting (rearranging) the data in the database.

• Obtaining subsets of the data for use.

A DBMS allows users to access and manage the data collected in a database.

Data management tasks (all done through the DBMS) can be divided into three categories:

Databases and DBMSes - DBMS Basics

• Creating Database Tables

• Viewing Records

• Sorting Records

• Querying a Database

• Generating Reports

Working With a Database

Text Logical Numeric Date/Time

Memo Binary Counter

• The first step in building a database is to create its tables. This means identifying, naming, and organizing its fields to receive data.

• Databases can store the following types of fields:

Working With a Database –Creating Database Tables

• You can create forms that let you view and enter data for one record at a time.

• Database tools such as masks can validate data as it is entered and thus ensure the data is in the correct format.

Working With a Database –Creating Database Tables

• A filter is a tool that lets you view records that match a given criteria.

• Filters are helpful when searching for certain types of information in a large database with many records.

• A form can work with a filter, but enables you to view information about a single record.

Working With a Database - Viewing Records

• Sorting means arranging the records in a database.

• A DBMS enables you to sort records alphabetically, numerically, and chronologically.

• You can sort records in ascending (A-Z) order or descending (Z-A) order.

Working With a Database - Sorting Records

• SQL

• Query by Example (QBE)

• Xbase

A query is a statement you define, which tells the DBMS to find records that match criteria you specify.

Modern DMBS software provides built-in querying tools, based on one or more of the following languages:

Working With a Database -Querying a Database

• A report is a subset of information from a database, produced in printed form.

• You can generate the data for a report by using a query, filter, or other tools.

• Reports can be formatted in a wide variety of ways.

Working With a Database -Generating Reports

• Enterprise software is a large-scale application based on a DBMS, used by a large organization.

• Enterprise software can meet the needs of many different users in different locations.

• In an enterprise, different users by have different interfaces to the database, so they can work only with the data they need.

Enterprise Software

• Define the terms database and database management system (DBMS).

• List three tasks that a DBMS enables users to do.

• Differentiate between flat-file databases and relational databases.

• List three steps needed to create a database.

• Explain the purpose of filters and forms.

• List three examples of query languages.


NetworkingBasics

les s on 17


• The Uses of a Network • How Networks are Structured • Network Topologies for LANs • Network Media and Hardware • Network Software

• Simultaneous Access

• Shared Peripheral Devices

• Personal Communication

• Easier Backup

A network connects computers so they can communicate, exchange information, and share resources.

The main benefits of using a network are:

The Uses of a Network

• In organizations, many people may need to use the same data or programs. A network solves this problem.

• Shared data and programs can be stored on a central network server. A server that stores data files may be called a file server.

• Managers may assign access rights to users. Some users may only be able to read data, others may be able to make changes to existing files.

The Uses of a Network -Simultaneous Access

Read/writeRead/writeRead/writeRead/writeRead/writeRead only

• Because peripheral (external) devices like printers can be expensive, it is cost-effective to connect a device to a network so users can share it.

• Through a process called spooling, users can send multiple documents (called print jobs) to a networked printer at the same time. The documents are temporarily stored on the server and printed in turn.

The Uses of a Network -Shared Peripheral Devices

• One of the most common uses of networks is for electronic mail (e-mail).

• An e-mail system enables users to exchange written messages (often with data files attached) across the local network or over the Internet.

• Two other popular network-based communications systems are teleconferencing and videoconferencing.

The Uses of a Network -Personal Communication

1 2 3 4

• Networks enable managers to easily back up (make backup copies of) important data.

• Administrators commonly back up shared data files stored on the server, but may also use the network to back up files on users' PCs.

The Uses of a Network - Easier Backup

• Local Area Networks (LANs)

• Wide Area Networks (WANs)

• Server-Based Networks

• Client/Server Networks

• Peer-to-Peer Networks

How Networks are Structured

• A LAN is a network whose computers are located relatively near one another. The nodes may be connected by a cable, infrared link, or small transmitters.

• A network transmits data among computers by breaking it into small pieces, called packets.

• Every LAN uses a protocol – a set of rules that governs how packets are configured and transmitted.

How Networks are Structured –Local Area Networks (LANs)

• Multiple LANs can be connected together using devices such as bridges, routers, or gateways, which enable them to share data.

• A WAN is two or more LANs connected together. The LANs can be many miles apart.

• To cover great distances, WANs may transmit data over leased high-speed phone lines or wireless links such as satellites.

How Networks are Structured –Wide Area Networks (WANs)

LAN 1

WAN

LAN 2

Type Aheader

Payload Type Aheader

Payload

Type Aheader

Payload

Significantgeographical

distance

ROUTER ROUTER

SERVER SERVER

• In addition to the individual users' PCs (nodes), many networks use a central computer, called a server.

• A server has a large hard disk for shared storage. It may provide other services to the nodes, as well.

• In a file server network, nodes can access files on the server, but not necessarily on other nodes.

How Networks are Structured –Server-Based Networks

A gateway performs the translationbetween two different types of networks.

1

2

3

• In client/server computing, individual nodes share the processing and storage workload with the server.

• Client/server networks require specialized software that enables nodes and the server to collaborate on processing and storage, but no special type of network hardware.

How Networks are Structured –Client/Server Networks

1

2

3

• In a peer-to-peer network, all nodes have an equal relation to one another.

• Each node usually has access to some resources on other nodes, so users can share files, programs, or devices on other users' systems.

• Some peer-to-peer networks use a server, but some do not.

How Networks are Structured –Peer-to-Peer Networks

• Bus. Each node is connected in series along a single conduit.

• Star. All nodes are connected to a central hub.

• Ring. Nodes are connected in a circular chain, with the conduit beginning and ending at the same computer.

• Mesh. Each node has a separate connection to every other node.

A network's topology is the layout of the cables and devices that connect the nodes. The four most common network topologies are:

Network Topologies for LANs

• In a network, the media are the wires, cables and other means by which data travels from its source to its destination.

• The most common network media are twisted-pair cable, coaxial cable, fiber-optic cable, and wireless links.

• Each node uses a special device, called a network interface card (NIC). The card connects to the network media and controls the flow of data.

• NICs must use a common network technology to communicate. The most popular network technologies for LANs are Ethernet, Fast Ethernet, and Token Ring.

Network Media and Hardware

• Novell NetWare• Microsoft Windows NT Server• Microsoft Windows 2000• Banyan VINES• AppleShare• Linux

A network operating system (NOS) is the group of programs that manages the resources on a network.

Common network operating systems for PC-based networks include:

Network Software

• List the four benefits of using a network.

• Differentiate between LANs and WANs.

• Identify three common network topologies.

• Name four common network media.

• List four examples of network operating systems.


Networking at Home and Abroad

les s on 18


• Standard Telephone Lines

• Digital Telephone Lines

• Networks in the Home

• Networks commonly use dedicated media to transmit data. However, the public telephone system can also be used for data communications.

• Standard phone lines transmit data much more slowly than network media, but devices such as modems make phone lines practical for data transmission over long distances.

• Many people and businesses use modems to exchange data, and to establish connections with office networks.

Data Communications over Standard Telephone Lines

• Most telephone lines attached to home and businesses are analog, not digital.

• Because PCs transmit and receive data in digital format, a device called a modem is needed to convert digital data to analog format for transmission over phone lines.

• When receiving data from another computer, the modem converts it from analog format to digital format.

Data Communications over Standard Telephone Lines - Modems

The analog signal(audible)

is sent throughtelephone lines.

MODEM MODEM 011010001011010001

Digital signal Digital signal

This modem convertsdigital to analog.

This modem convertsanalog to digital.

• Transmission speed - the speed at which the modem sends data - which is measured in bits per second.

• Data compression, the technology the modem uses to shrink data so it can be transmitted faster.

• Error correction, the method the modem uses to ensure data is sent and received without errors.

• Internal versus external, which describes whether or not the modem fits inside the PC case.

When choosing a modem, consider the following factors:

Data Communications over Standard Telephone Lines - Choosing a Modem

Internal Modem External

Modem

• Sending a file to another computer is called uploading.

• Receiving a file from another computer is called downloading.

Data Communications over Standard Telephone Lines - Uses for a Modem

Modems are primarily used for file transfer, or sending files to a remote computer

• Telephone companies are now installing digital telephone lines, which are dedicated to transmitting data in digital format.

• Digital phone lines transmit data at much higher speeds than standard analog phone lines.

• Often, data travels across analog lines and digital lines. In such cases, data may need to be converted from one format to another multiple times before reaching its destination.

Using Digital Telephone Lines

12

3

4

• ISDN, T1, and T3

• DSL

• ATM

• Cable Modem

The most commonly used digital telephone services are:

Using Digital Telephone Lines -Common Digital Services

Using Digital Telephone Lines –ISDN, T1, and T3

• Integrated Services Digital Network (ISDN) is a system that replaces analog phone services with digital services.

• Basic rate ISDN (BRI) offers three channels on one phone line: two for data and one for control. BRI transmits data up to 128 Kbps.

• Primary rate ISDN (PRI) offers 24 channels at transmission speeds up to 1.544 Mbps. This is T1 service.

• Using even more channels, T3 service offers up to 672 channels and speeds up to 44.736 Mbps.

• Digital Subscriber Line (DSL) service is outpacing ISDN services.

• Standard DSL offers speeds of 52 Mbps using standard phone lines.

• Several types of DSL service are available, reaching transmission speeds up to 51.84 Mbps.

Using Digital Telephone Lines -DSL Technologies

• Asynchronous transfer mode (ATM) digital service is offered as a high-bandwidth, efficient means for transferring multimedia content, data, and voice over phone lines.

• Some types of ATM service can reach transmission speeds of 10,000 Mbps.

Using Digital Telephone Lines - ATM

• Cable modems allow users to connect their PCs to the Internet via the local cable television system.

• Cable companies offer Internet service by combining television and data signals and distributing them over the cable system.

• Cable modem service can achieve speeds of 27 Mbps.

Using Digital Telephone Lines -Cable Modem Connections

Home and BusinessSubscribers

Servers

TVsignals

Cable Company Head End

Distribution

Routers

Internet Backbone

• Because more homes now have multiple computers, home networks are gaining in popularity. Home networks offer the same advantages to home users as to a business.

• Home networks are typically based on existing telephone or wireless technologies.

• Popular PC operating systems, such as Windows and the Mac OS, provide simple networking tools that are adequate for running a home network.

Networks in the Home

• Explain how computer data travels over telephone lines.

• Explain a modem's function.

• List four features you should consider when evaluating modems.

• Differentiate four types of digital telephone services.

• Describe one potential use for a home network.

.


Internet Basicsles s on 19


• The Internet: Then and Now

• How the Internet Works

• Major Features of the Internet

• Online Services

• Internet Features in Application Programs

• The Internet was created by the Advanced Research Projects Agency (ARPA) and the U.S. Department of Defense for scientific and military communications.

• The Internet is a network of interconnected networks. Even if part of its infrastructure was destroyed, data could flow through the remaining networks.

• The Internet uses high-speed data lines, called backbones, to carry data. Smaller networks connect to the backbone, enabling any user on any network to exchange data with any other user.

The Internet: Then and Now

• TCP/IP

• Routing Traffic Across the Internet

• Addressing Schemes

• Domains and Subdomains

How the Internet Works

• Every computer and network on the Internet uses the same protocols (rules and procedures) to control timing and data format.

• The protocol used by the Internet is the Transmission Control Protocol/Internet Protocol, or TCP/IP.

• No matter what type of computer system you connect to the Internet, if it uses TCP/IP, it can exchange data with any other type of computer.

How the Internet Works - TCP/IP

• Most computers don't connect directly to the Internet. Instead, they connect to a smaller network that is connected to the Internet backbone.

• The Internet includes thousands of host computers (servers), which provide data and services as requested by client systems.

• When you use the Internet, your PC (a client) requests data from a host system. The request and data are broken into packets and travel across multiple networks before being reassembled at their destination.

How the Internet Works -Routing Traffic Across the Internet

• In order to communicate across the Internet, a computer must have a unique address.

• Every computer on the Internet has a unique numeric identifier, called an Internet Protocol (IP) address.

• Each IP address has four parts – each part a number between 0 and 255. An IP address might look like this: 205.46.117.104.

How the Internet Works -Addressing Schemes

• In addition to an IP address, most Internet hosts or servers have a Domain Name System (DNS) address, which uses words.

• A domain name identifies the type of institution that owns the computer. An Internet server owned by IBM might have the domain name ibm.com.

• Some enterprises have multiple servers, and identify them with subdomains, such as products.ibm.com.

How the Internet Works -Domains and Subdomains

• The World Wide Web

• E-Mail

• News

• Telnet

• File Transfer Protocol (FTP)

• Internet Relay Chat (IRC)

Major Features of the Internet

• The World Wide Web is a part of the Internet, which supports hypertext documents, allowing users to view and navigate different types of data.

• A Web page is a document encoded with hypertext markup language (HTML) tags.

• HTML allows designers to link content together via hyperlinks.

• Every Web page has an address, a Uniform Resource Locator (URL).

Major Features of the Internet -The World Wide Web

This address is for anInternet server that usesThe hypertext transfer protocol.

This address is for anInternet server that usesThe hypertext transfer protocol.

This site belongs to acompany named Glencoe.

This site belongs to acompany named Glencoe.

This site is on the partof the Internet knownas the World Wide Web.

This site is on the partof the Internet knownas the World Wide Web.

To find the specific Web pagesthat accompany this book, yourbrowser follows the URL’s pathto a folder named “norton,” thento a subfolder named “online.”

To find the specific Web pagesthat accompany this book, yourbrowser follows the URL’s pathto a folder named “norton,” thento a subfolder named “online.”

• Electronic mail (e-mail) is the most popular reason people use the Internet.

• To create, send, and receive e-mail messages, you need an e-mail program and an account on an Internet mail server with a domain name.

• To use e-mail, a user must have an e-mail address, which you create by adding your user name to thee-mail server's domain name, as in [email protected].

Major Features of the Internet - E-Mail

• One Internet-based service, called news, includes tens of thousands of newsgroups.

• Each newsgroup hosts discussions on a specific topic. A newsgroup's name indicates its users' special topic of interest, such as alt.food.cake.

• To participate in a newsgroup, you need a newsreader program that lets you read articles that have been posted on a news server. You can post articles for others to read and respond to.

Major Features of the Internet - News

• Telnet is a specialized service that lets you use one computer to access the contents of another computer –a Telnet host.

• A Telnet program creates a "window" into the host so you can access files, issue commands, and exchange data.

• Telnet is widely used by libraries, to allow visitors to look up information, find articles, and so on.

Major Features of the Internet - Telnet

• File transfer protocol (FTP) is the Internet tool used to copy files from one computer to another.

• Using a special FTP program or a Web browser, you can log into an FTP host computer over the Internet and copy files onto your computer.

• FTP is handy for finding and copying software files, articles, and other types of data. Universities and software companies use FTP servers to provide visitors with access to data.

Major Features of the Internet -File Transfer Protocol (FTP)

• Internet Relay Chat (IRC) is a service that allows users to communicate in real time by typing text in a special window.

• Like news, there are hundreds of IRC "channels," each devoted to a subject or user group.

• You can use a special IRC program to participate in chatroom discussions, but many chatrooms are set up in Web sites, enabling visitors to chat directly in their browser window.

Major Features of the Internet –Internet Relay Chat (IRC)

• An online service is a company that provides access to e-mail, discussion groups, databases on various subjects, and the Internet.

• America Online, CompuServe, and Prodigy are examples of popular online services.

Online Services

• Popular application programs, such as word processors and spreadsheets, feature Internet-related capabilities.

• Using these special features, you may be able to create content for publication on the Internet or view content directly from the Internet.

Internet-Related Features in Application Programs

• Name the two organizations that created the network now called the Internet.

• Explain the importance of TCP/IP to the Internet.

• Describe the basic structure of the Internet.

• List the major services the Internet provides to its users.

• Identify two key Internet-related features found in many software applications.


Getting Online, Working Online

les s on 20


• Accessing the Internet

• Connecting a PC to the Internet

• Working on the Internet

• Commerce on the World Wide Web

• Non-Standard Methods

• Common Connection Methods

• High-Speed Data Links

Accessing the Internet

• Direct connection – connects an isolated PC directly to the Internet backbone via serial line interface protocol (SLIP) or point-to-point protocol (PPP).

• Remote terminal connection – allows the user to exchange commands and data in ASCII text format with a UNIX host computer.

• Gateway connection – connects a non-TCP/IP network to the Internet via a gateway.

These methods of connecting to the Internet are not commonly used:

Accessing the Internet -Non-Standard Methods

• Connection through a LAN – if a LAN uses TCP/IP, it can exchange data over the Internet without a gateway. If the LAN is connected to the Internet via a router, the connection is extended to all nodes on the network.

• Connection through a modem – if a stand-alone PC has access to a modem and phone line, it can connect directly or via an Internet Service Provider (ISP). ISP accounts are the most common type of connection.

Here are some very common methods for connecting PCs to the Internet:

Accessing the Internet -Common Connection Methods

• ISDN service can transmit data up to 128 Kbps and carries voice and data signals over a single connection.

• xDSL services are available in several forms with download speeds up to 52 Mbps, and also offer simultaneous voice and data transmissions.

• Cable modem service offers high-speed data transmission over a cable television system's existing coaxial lines.

Because modem speeds are limited to 56 Kbps, many home users and small businesses connect to the Internet via high-speed lines, such as:

Accessing the Internet -High-Speed Data Links

• To connect a PC to the Internet, you use applications and network connections that conform to the Winsock standard.

• The Winsock standard ensures that connections and applications use TCP/IP protocols and can communicate with each other.

• You can mix and match any Winsock application and connection and be sure they will work together.

Connecting a PC to the Internet

• Businesses and Firewalls

• Intranets and Extranets

• Issues for Telecommuters

Working on the Internet

• Many businesses connect their LANs to the Internet, making their data vulnerable to access by unauthorized users, such as hackers.

• Businesses can use a firewall to control access to their network from the Internet, by persons outside the company.

• A firewall gives outsiders access to public areas of a network while restricting access to protected parts of the network.

Working on the Internet -Businesses and Firewalls

STOP

Invalidpassword

• Many organizations are configuring their internal networks to resemble the World Wide Web, so users can navigate them with a browser.

• An intranet is a LAN or WAN that uses TCP/IP but is accessible only to internal users. Intranets are not connected to the Internet.

• An extranet is an intranet that allows outside access via the Internet. Usually, external users must log in with an ID and password.

Working on the Internet -Intranets and Extranets

• A telecommuter is someone who works outside the workplace, but uses a computer and communications software to access the company's network, usually over the Internet.

• When accessing a corporate network online, telecommuters need to be aware of issues such as security, ownership of sensitive data, libel, and appropriate use of business resources.

Working on the Internet -Issues for Telecommuters

• The Web is a vehicle for electronic commerce(e-commerce), which simply means doing business online.

• For consumers, e-commerce means being able to securely shop, pay bills, and conduct other types of transactions online.

• For businesses, e-commerce means a new way to sell and distribute goods and services, and to expand markets beyond physical locations or geographical boundaries.

Commerce on the World Wide Web

• Describe how to connect a computer to the Internet.

• Identify three kinds of high-speed data links commonly used to connect to the Internet.

• Describe the process of connecting a PC to the Internet through an ISP account.

• Explain what a firewall is, and the uses for a firewall.

• Define the terms intranet and extranet.

• Explain what is meant by e-commerce and how it affects consumers and businesses.


Working with

les s on 21

Images


• Computer Platforms Used for Graphics

• Types of Graphics Files

• Getting Images into Your Computer

• Copyright Issues

• The Macintosh started the era of art on the PC in 1984. With its mouse and GUI, the Mac quickly became popular with designers.

• With the release of Windows, PCs caught up with the Mac in terms of graphics capabilities. Designers routinely use PCs and Macs together.

• Because of their power and cost, workstations are used only for the most demanding graphics applications.

Computer Platforms Used for Graphics

Because graphics programs support so many different file formats, compatibility becomes an important issue for designers.

• Bitmaps

• Vectors

Graphics files can be saved in many different ways, but fall into two basic groups:

Types of Graphics Files

• A bitmap is a grid whose cells are filled with a color. If you zoom into a bitmap-based line on the computer's screen, you can see the cells (pixels) that comprise it.

• Bitmaps are sometimes called raster images or bitmapped images.

• Bitmap software lets you control each pixel in an image. This software keeps track of all the pixels in an image, which may number in the millions.

Types of Graphics Files - Bitmaps

Zooming in ona bitmapped line

• A vector is a set of mathematical equations that describe the characteristics of a line or shape.

• A vector-based program does not see a graphical entity as a set of pixels. Instead, the program sees the entity as a set of start and end points, with thickness, color, and other attributes.

Types of Graphics Files - Vectors

320,240

80,60

• A file format is a standardized method of encoding data for storage.

• There are many different file formats for graphics. Some programs recognize more formats than others do.

• Some programs cannot use certain file formats. These files are said to be incompatible with the program.

Types of Graphics Files -File Formats and Compatibility Issues

• To solve incompatibility problems, designers can save bitmap files in one of several standard formats, which can be used in many programs.

• The most commonly used bitmap file formats are BMP, PICT, TIFF, JPEG, GIF, and PNG.

• Most vector programs use their own proprietary file format, but may recognize standard vector formats such as DXF and IGES.

Types of Graphics Files –Standard File Formats

• Scanners

• Digital cameras

• Clip art

• Electronic photographs

Graphics programs let you start an image from scratch, but designers often use existing images, which they load from various sources.

The four most common sources of digital images are:

Getting Images into Your Computer

• Copyright is an important concern if a designer wants to reuse art created by someone else.

• Copyright laws govern the way images can be reused and distributed and thus protect the rights of the images’ owners.

Copyright Issues

• Identify three computer platforms widely used in graphic design.

• Define bitmap and vector, and differentiate these file types.

• List the standard file formats for bitmap and vector images.

• List four ways to load graphic files into a computer.

• Discuss copyright issues that arise from the use of computer graphics.


les s on 22

Graphics Software

This lesson includes the following sections:• Paint Programs

• Photo-Manipulation Programs

• Draw Programs

• Computer-Aided Design Programs

• 3-D Modeling Programs

• Animation

• Graphics and the World Wide Web

• Paint programs work with bitmap images and manage the individual pixels that make up an image.

• Paint programs provide a variety of tools that can add special effects to an image.

• It can be difficult to edit an entity in a paint program because the program does not see the entity as a whole, but as a set of pixels. To edit the image, you must make changes to the pixels that comprise it.

Paint Programs

As the circle is zoomed on the screen,the individual pixels can be seen.

Pixelization is characteristicof paint programs.

• Photo-manipulation programs are bitmap-based programs, which are used primarily to edit electronic or digitized photographs.

• Photo-manipulation programs can repair problems with an image, such as adjusting colors or hiding mistakes.

• Photo-manipulation programs can produce sophisticated effects, such as combining multiple images into a seamless whole, hiding parts of an image, and more.

Photo-Manipulation Programs

The airbrush tool canbe used to repair a

scratched photograph.

• Draw programs work with vectors and give the designer a great deal of flexibility in editing an image.

• Objects created in a draw program can be altered easily and without loss of image quality.

• Draw programs work well with text.

Draw Programs

• Computer-Aided Design (CAD) programs are used in technical design fields to create models of objects that will be built or manufactured.

• CAD software allows users to design objects in three dimensions (3-D) and to produce 3-D wireframe and solid models.

• CAD products provide the user with high precision, and enable the user to divide drawings into layers, and add accurate dimensions (measurements) to a drawing.

Computer-Aided Design Programs

• Surface modeling

• Solid modeling

• Polygonal modeling

• Spline-based modeling

Designers use 3-D modeling programs to build three-dimensional models of objects and characters, and to add special effects to them.

Modeling programs use four techniques to build models:

3-D Modeling Programs

Gear Model in 3-D

• Computers are used to create animation in various fields, including games and movies.

• Fly-bys and walk-throughs are basic types of computer animation.

• Character animation is the art of creating a character and making it move in a lifelike manner.

• Compositing tools allow designers to add characters and objects to scenes that did not originally contain them.

Animation

Fly-by frame sequence

• Web pages support many types of graphics, including bullets, rules, logos, complex artwork, and photographs.

• The GIF and JPEG image formats are the most widely used formats on the Web.

• Animation can be added to a Web page by using simple animated GIF images or plug-in software such as Flash or Shockwave.

Graphics and the World Wide Web

• List five types of graphics software and their uses.

• Differentiate the way bitmap and vector graphics programs work.

• Describe four methods for creating 3-D computer models.

• Identify three categories of computer-generated animation.

• Name five types of graphics elements commonly found in Web pages.


les s on 23

Understanding Multimedia


• Multimedia, Interactivity, and New Media

• Information in Layers and Dimensions

• Hardware Considerations for Multimedia

• Applications for Multimedia

• Multimedia

• Interactivity

• New Media and Digital Convergence

Multimedia, Interactivity, and New Media Defined

• A medium is a way of conveying information. Speech is one medium, text is another.

• There are many kinds of unique media. ("Media" is the plural of "medium.")

• Multimedia is the use of more than one type of medium at the same time to convey a message or information.A lecture presented along with slides is an example of a simple multimedia event.

Multimedia, Interactivity, andNew Media Defined - Multimedia

• Like television, a PC can present many media types simultaneously. For example, text, animation, music, and narration can all play at one time.

• TV is not interactive; it only delivers content. The PC enables the use of interactive multimedia such as games and reference products.

• Interactivity means that the user and program respond to one another. The program provides an ever-changing array of choices, which the user selects to direct the flow of the program.

Multimedia, Interactivity, and New Media Defined - Interactivity

• "New media" is a term that encompasses all types of interactive multimedia technologies.

• New media bring together not only multimedia content, but delivery technologies such as cable, telephone lines, networks, and the Internet.

• New media is based on the concept of digital convergence, which means many different technologies can be used together to deliver different types of content in one digital stream.

Multimedia, Interactivity, and New Media Defined - New Media and Digital Convergence

• The Importance of Content

• Hypermedia and Navigation

Information in Layers and Dimensions

• The purpose of multimedia is to make information (content) more interesting, compelling, or enjoyable, as well as easy to navigate.

• Multimedia technologies give users choices of the type of content that is presented, and the manner in which it is presented.

• Regardless of the technologies used in multimedia, the primary focus is on providing high-quality content.

Information in Layers and Dimensions -The Importance of Content

• The process of moving through electronic information is called navigation.

• Well designed multimedia products provide a variety of methods for the user to navigate and choose content. Multimedia navigation is based on “hypermedia”.

• Hypermedia allows different types of content to be linked together. By choosing a hyperlink, WWW users jump to a new web page or multimedia feature.

Information in Layers and Dimensions -Hypermedia and Navigation

REWIND BACK 1 STOP PAUSE ADV.1 PLAY F-FWD

external links

Navigation buttons for embedded

media on this site

• Most new PCs are multimedia-capable, featuring all the hardware required to play back multimedia content.

• To play multimedia content, a PC needs (at the very least) a sound card, speakers, and a CD-ROM or DVD-ROM drive. A large hard disk and lots of RAM are also helpful.

• New PCs must meet requirements set in the PC 97 or PC 99 standard to be considered multimedia-compliant.

Hardware Considerations for Multimedia

• In the School

• In the Workplace

• In the Home

Applications for Multimedia

• Many types of multimedia tools are being used in schools, from CD-based reference products, to games, to online collaboration.

• Distance learning technologies allow schools to provide courses online, over the Internet. These online learning environments are called virtual universities.

Applications for Multimedia - In the School

• Companies are increasingly using multimedia for sales, marketing, and training.

• Using computer-based training (CBT) products, companies can quickly and cost-effectively teach employees new skills.

• Because multimedia content can be distributed over the Web, many companies have developed online outlets which enable customers to view and purchase products from their PC.

Applications for Multimedia –In the Workplace

• Reference materials

• Self-help and instruction

• Entertainment

In the home, multimedia products are used largely for the following purposes:

Applications for Multimedia -In the Home

• Define multimedia, interactivity, and new media.

• Explain how different types of media are used to create multimedia events.

• List three essential hardware components for a multimedia-capable PC.

• Name four specific uses for multimedia products.


Creating & Distributing

New Media Content

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• Creating New Media Content

• Technologies That Support New Media

• Distributing New Media Content

• Defining the Audience

• Design and Storyboarding

• Choosing Tools, Creating Content, and Multimedia Authoring

• Testing

The creation of multimedia products (such as CD-ROM encyclopedias or online games) requires the skills of many people, working in a process that involves these phases:

Creating New Media Content

• Before any code is written or graphics are drawn, the multimedia team must determine who will be the audience for its product.

• By identifying the audience, the developers can determine the users' needs and manner in which the product will be used.

• Developers typically define their product's audience by attempting to answer a series of questions about the users. The answers determine how the product will ultimately look and behave.

Creating New Media Content -Defining the Audience

• Multimedia design involves determining the exact content the product must include, the order in which it will flow, and the types of tools and options the user will want.

• Developers often map out the flow of a product's content by creating storyboards – sketches of scenes from the product.

Creating New Media Content -Design and Storyboarding

• Multimedia developers can choose from a wide range of tools for creating their products. The tools used depend on the type of content, interactive capabilities, and navigational features desired in the product.

• Different team members create different kinds of content for the product. Writers create text content or narration scripts, for instance.

• The process of combining various elements into the finished product is called multimedia authoring, and requires special tools that recognize and control all types of content.

Creating New Media Content - Choosing Tools, Creating Content and Authoring

• Before being released to its end users, a multimedia product goes through various types of testing.

• If the product fails any portion of a test, it may be sent back into the development process or even may be redesigned from scratch.

Creating New Media Content - Testing

• MPEG and JPEG

• QuickTime

• Video for Windows

• RealAudio and RealVideo

• Shockwave

In order to present various types of content and allow user interaction, multimedia programs may use a wide range of technologies, such as:

Technologies That Support New Media

• High-quality images consume a great deal of bandwidth and can cause multimedia products to perform poorly if not handled in an efficient way.

• MPEG is a standard file format for full-motion video, which allows for efficient compression while maintaining high image quality.

• JPEG is a standard file format for still images, such as photographs, which also provides compression and high image quality.

Technologies That Support New Media -MPEG and JPEG

24-7

• QuickTime is a multimedia file format originally meant for use on Apple computers. QuickTime-format files are used on the Web and in stand-alone multimedia products.

• QuickTime allows for high-quality streaming audio and video. The QuickTime player supports a variety of file formats, including MPEG.

• QuickTime VR uses QuickTime technology to present immersive environments, with almost the same impact as true 3-D.

Technologies That Support New Media -QuickTime

24-8

• Video for Windows is a very basic format that allows full-motion audio and video to be played on a PC.

• Though limited in its capabilities, Video for Windows does not require any special hardware or software, and files can be played on any Windows PC.

Technologies That Support New Media -Video for Windows

• The RealPlayer is a multimedia utility that can play streaming audio and video files, distributed over the Internet or on CD.

• The RealPlayer plays audio files in RealAudio format, and video files in RealVideo format.

• Online media outlets, such as CNN and the Weather Channel, provide RealPlayer-format versions of their programming, which can be viewed from the Web.

Technologies That Support New Media -RealAudio and RealVideo

• Shockwave is a specialized file format that supports full-motion, interactive animation and sound.

• Using the Shockwave plug-in utility, you can view Shockwave-format animations directly in your browser window on the Web.

• Shockwave is unique because it allows developers to create fully interactive animations, such as games, which can be distributed online or on disk.

Technologies That Support New Media -Shockwave

24-11

• CD-ROM or DVD-ROM

• The Internet or a network connection

• Television

Currently, multimedia content is typically delivered to users by one of three means:

Distributing New Media Content

• Describe the phases of the multimedia design process.

• List three technologies that support full-motion video in multimedia products.

• Identify one technology that supports streaming audio and video on the Web.

• Name three ways in which multimedia content is commonly distributed.


The Basics of Information Systems

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• Uses for Information Systems

• The Parts of an Information System

The Purpose of Information Systems


• The Purpose of Information Systems

• Types of Information Systems

• The Information Systems Department

• An information system is a mechanism that helps people collect, store, organize, and use information. This is the primary use for computers.

• An information system can be manual, like a card catalog or an address book.

• Computerized information systems can range from a simple database of names to a satellite-tracking system.

The Purpose of Information Systems -Uses for Information Systems

All information systems, regardless of their type, serve the same purpose – to help users get a certain type of value from their information.

• A physical means for storing information, such as disks.

• A procedure for handling information, to ensure its integrity.

• Rules regarding the use or distribution of information, to ensure it is used by the right people.

Any information system has three parts:

The Purpose of Information Systems –Parts of an Information System

• Office Automation Systems

• Transaction Processing Systems

• Decision Support Systems

• Management Information Systems

• Expert Systems

Types of Information Systems

• Office automation systems are used to automate routine office tasks, such as the creation of documents, billing, and others.

• Office automation systems can be built from off-the-shelf applications – standard productivity software that most users are familiar with.

• In some office systems, commercial software may be customized to perform specific tasks, but this is not always necessary.

Types of Information Systems -Office Automation Systems

• A transaction processing system is used to handle the processing and tracking of transactions.

• A transaction is an event that can occur as a series of steps, such as taking and fulfilling an order from a customer.

Types of Information Systems -Transaction Processing Systems

• A decision support system collects various types of business data, and is used to generate special reports that help managers make decisions.

• A decision support system may use data from a company's transaction processing system and from external sources, such as stock market reports, information about competitors, and so on.

• These systems provide highly tailored, structured reports that can be used for very specific business situations.

Types of Information Systems -Decision Support Systems

Input and feedback

Query, model andanalysis results

Interaction

Manager orStaff Specialist

Decision SupportSoftware

Mathematical modeling toolsDatabase manager

External Data Sources

GovernmentalCustomers and

SuppliesCompetition and

global markets

• A management information system (MIS) is designed to provide information that is design for use by different types of managers.

• This type of system can create reports that meet the needs of managers at different levels.

• Senior-level managers need different types of information than mid- or low-level managers. These people may need entirely different types of information, or to view the same type of information in unique ways.

Types of Information Systems -Management Information Systems

• An expert system is a specialized information system that performs tasks normally done by people, such as making decisions.

• Expert systems are used to approve bank loans, make large-scale purchasing decisions, and assist with medical diagnoses.

• Expert systems rely on huge, detailed databases (knowledge bases). Special software, called an inference engine, analyzes data to answer questions or make choices.

Types of Information Systems –Expert Systems

• The Role of the IS Department

• Role Players in an IS Department

The Information Systems Department

• The Information Systems (IS) department is responsible for designing, building, and managing an organization's information systems.

• In years past, the IS department served only the informational needs of managers. Today, the IS team supports all workers in a business, and supports the business' mission, as well.

• An IS department's tasks include designing, planning, installing, and maintaining systems; generating reports; and cost control.

The Information Systems Department -The Role of the IS Department

An IS department can include many members with many different skills. A large IS staff may include:

Managers Purchasing AgentsComputer Scientists Security ManagersSystems Analysts TrainersProgrammers User Assistance ArchitectsDatabase Specialists Technical WritersSystem or Network ManagersHardware Maintenance Technicians

The Information Systems Department -Role Players in an IS Department

• Define the term information system.

• Name five types of information systems.

• Explain the purpose of each major type of information system.

• List at least six jobs that are part of an IS department.


Building Information Systems

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This lesson includes the following sections:• The Systems Development Life Cycle

• Phase 1: Needs Analysis

• Phase 2: Systems Design

• Phase 3: Development

• Phase 4: Implementation

• Phase 5: Maintenance

• Needs analysis

• Systems design

• Development

• Implementation

• Maintenance

The systems development life cycle (SDLC) is an organized method for building an information system.

The SDLC includes five phases:

The Systems Development Life Cycle

• In the needs analysis phase, the development team must define the IS-related problem, analyze the current system, and select a solution.

• Analysts may document the current system using tools such as data flow diagrams, structured English, or decisions trees.

• In this phase, IS workers learn how the current system functions and how it meets (or fails to meet) the organization's informational needs.

Phase 1: Needs Analysis

In this phase, designers may create working models, or prototypes, of parts of the system, to see if their designs will work.

• Top-down design, in which designers start with the large picture and move to the details of its function.

• Bottom-up design, in which designers start with the details and move to the major functions.

During systems design, the team determines how the selected solution will work. To do this, designers may use two design methods:

Phase 2: Systems Design

• In the development phase, software components are either created or acquired.

• Programmers may elect to build required software from scratch, or to customize software that is purchased from another source.

• In this phase, documentation (such as user manuals or online help systems) is also developed.

Phase 3: Development

• Direct – all users stop using the old system and start using the new one.

• Parallel –the old system stays in use as increasing amounts of data are processed in the new one.

• Phased – users start using the new system, one component at a time.

• Pilot – users at one site use the new system while all other users keep the old system.

During implementation, the new system is installed. Four conversion methods can be use to move from an old system to a new one:

Phase 4: Implementation

• During the maintenance phase, continuing support is provided to the new system's users.

• Changes and upgrades are part of the maintenance phase, as is the process of isolating and repairing problems with the system.

Phase 5: Maintenance

• Define the term systems development life cycle (SDLC).

• Identify the five phases in the SDLC.

• Name the IS professionals involved in each phase of the SDLC.

• Describe four ways an organization can convert from an old information system to a new one.


Creating Computer Programs

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• What is a Computer Program?

• How Programs Solve Problems

• Two Approaches: Structured &Object-Oriented Programming

• Files

• Hardware/Software Interaction

What is a Computer Program?

What is a Computer Program? - Files

Typically, a program is stored as a collection of files. Some common file types used in programs are:

• Executable (.EXE) files actually send commands to the processor.

• Dynamic Link Library (.DLL) files are partial .EXE files.

• Initialization (.INI) files contain configuration information for a program.

• Help (.HLP) files contain information for the user.

• The program tells the CPU to process interrupts, or sets of steps the CPU must follow to perform a task.

• To control hardware, a program must be written in binary numbers (1s and 0s). This code is called machine code or machine language.

• Programmers use programming languages to write code in nearly human language. The resulting description is called source code.

• Compilers and interpreters translate a program into object code, the binary version of source code.

What is a Computer Program? -Hardware/Software Interaction

• Program Control Flow

• Algorithms

• Heuristics

• Common Flow Patterns

• Variables and Functions

How Programs Solve Problems

• The order in which program statements are executed is called program control flow.

• To determine program control flow, programmers may use a flowchart to map the program's sequence.

• Programmers may also create a simple text version of a program's code – called pseudocode – to determine how the program will flow.

How Programs Solve Problems –Program Control Flow

This flowchartshows that thesequence canvary dependingon conditions.

• An algorithm is a set of steps that always lead to a solution. The steps are always the same, whether the problem is being solved manually or with a PC.

• A computer program may contain thousands of algorithms, each one devoted to a single task.

• An algorithm, for example, will find the highest point in a mountain range by comparing all the points until the highest one is found.

How Programs Solve Problems - Algorithms

no

• If a problem is too complex to be solved by an algorithm, a programmer may try to solve it by using heuristics.

• Heuristics are like algorithms, and will always find a solution to a problem. But unlike algorithms, heuristics are not guaranteed to find the best possible solution.

• A heuristic, for example, may find the highest point in a mountain range by comparing random points, but this process may never find the highest one.

How Programs Solve Problems - Heuristics

• To determine when and where to pass program control, a developer may use conditional statements or loops.

• A conditional statement determines whether a condition is true. If so, control flows to the next part of the program.

• A loop repeats again and again until a condition is met. Control then passes to another part of the program.

How Programs Solve Problems -Common Flow Patterns

• A variable is a named placeholder for data that is being processed. Programs contain variables to hold inputs from users, for example.

• A function is a set of steps that are followed to perform a specific task. By assembling a collection of functions together, a developer can build a complete program.

How Programs Solve Problems -Variables and Functions

• Structured programming

• Object-oriented programming

Early programmers allowed control to pass from one part of a program to another by using goto statements. Control would "go to" a different part of the program when conditions allowed.

Goto statements cause programs to become very complex. To eliminate their use, programmers developed two approaches to development:

Two Approaches: Structured & Object-Oriented Programming

This type of programming has fallen into disfavor.

• Sequence structure defines the default control flow.

• Selection structures are built around conditional statements.

• Repetition (looping) structures use loops, which execute according to the results of conditional statements.

Structured programming uses three types of control structures to make program control flow more predictable:

Two Approaches: Structured & Object-Oriented Programming - Structured Programming

• In object-oriented programming (OOP), programs are built from blocks of code, called objects. Each object has functions and characteristics (attributes), and can contain (encapsulate) other objects.

• Objects that share common attributes can be grouped into classes. Classes can be divided into subclasses.

• In OOP, objects communicate with one another by exchanging messages.

Two Approaches: Structured & Object-Oriented Programming - Object-Oriented Programming

• Define the term computer program.

• Describe the use of flowcharts and pseudocode in programming.

• Identify two ways in which a program can work toward a solution.

• Differentiate the two main approaches to computer programming.

• List and describe three elements of object-oriented programming.


Programming Languages and the

Programming Process

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• The Evolution of Programming Languages

• The Systems Development Life Cycle for Programming

• Machine languages

• Assembly languages

• Higher-level languages

To build programs, people use languages that are similar to human language. The results are translated into machine code, which computers understand.

Programming languages fall into three broad categories:

The Evolution of Programming Languages

• Machine languages (first-generation languages) are the most basic type of computer languages, consisting of strings of numbers the computer's hardware can use.

• Different types of hardware use different machine code. For example, IBM computers use different machine language than Apple computers.

The Evolution of Programming Languages -Machine Languages

• Assembly languages (second-generation languages) are only somewhat easier to work with than machine languages.

• To create programs in assembly language, developers use cryptic English-like phrases to represent strings of numbers.

• The code is then translated into object code, using a translator called an assembler.

The Evolution of Programming Languages -Assembly Languages

Assembler

Assemblycode

Object code

• Third-generation languages

• Fourth-generation languages

• Fifth-generation languages

Higher-level languages are more powerful than assembly language and allow the programmer to work in a more English-like environment.

Higher-level programming languages are divided into three "generations," each more powerful than the last:

The Evolution of Programming Languages -Higher-Level Languages

FORTAN CCOBOL C++BASIC JavaPascal ActiveX

• Third-generation languages (3GLs) are the first to use true English-like phrasing, making them easier to use than previous languages.

• 3GLs are portable, meaning the object code created for one type of system can be translated for use on a different type of system.

• The following languages are 3GLs:

Higher-Level Languages -Third-Generation Languages

Visual Basic (VB)VisualAgeAuthoring environments

• Fourth-generation languages (4GLs) are even easier to use than 3GLs.

• 4GLs may use a text-based environment (like a 3GL) or may allow the programmer to work in a visual environment, using graphical tools.

• The following languages are 4GLs:

Higher-Level Languages -Fourth-Generation Languages

• Fifth-generation languages (5GLs) are an issue of debate in the programming community – some programmers cannot agree that they even exist.

• These high-level languages would use artificial intelligence to create software, making 5GLs extremely difficult to develop.

Higher-Level Languages -Fifth-Generation Languages

• Phase 1: Needs Analysis

• Phase 2: Program Design

• Phase 3: Development

• Phase 4: Implementation

• Phase 5: Maintenance

The SDLC for programming follows the same phases as the SDLC for information systems development:

The Systems Development Life Cycle for Programming

• Identify the three main categories of programming languages.

• Describe the five generations of programming languages.

• Name at least five major programming languages.

• Describe a visual programming environment and how it is used.

• List the five phases of the software development life cycle.


Computers and the Individual

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• Ergonomics and Health Issues

• Privacy Issues

• Ergonomics Defined

• Repetitive Stress Injuries

• Avoiding Repetitive Stress Injuries

• Eyestrain

• Electromagnetic Fields

Ergonomics and Health Issues

• Repetitive injuries

• Carpal tunnel syndrome

• Eyestrain

• Exposure to electromagnetic fields

Ergonomics is the study of the physical relationship between people and their tools – such as computers.

Extended or improper computer use may result in a number of ailments, such as:

Ergonomics and Health Issues -Ergonomics Defined

• Repetitive stress injuries (RSIs) result from using the body continuously in ways it was not designed to work.

• RSIs have appeared in office workers who spend a lot of time using the computer keyboard and mouse.

• Carpal tunnel syndrome is a common type of repetitive stress injury, which may be caused by extended or improper use of a computer keyboard.

Ergonomics and Health Issues -Repetitive Stress Injuries

• One of the easiest ways to avoid RSIs is to use ergonomically correct furniture, including an ergonomically designed chair and keyboard.

• An ergonomically correct chair features adjustable height, lower-back support, and armrests. It should allow you to type with your forearms parallel to the floor.

• An ergonomically correct keyboard is designed to allow the hands to rest in a natural, comfortable position so you can type without overreaching or getting fatigued.

Ergonomics and Health Issues -Avoiding Repetitive Stress Injuries

Lower back support

Armrests

Adjustable height

Angles place handsin a natural position

• Many computer users find their vision deteriorating after a while. This is caused by using the PC too long, poor positioning, or other factors.

• To avoid eyestrain, don't stare at the screen too long, place the monitor from 2 to 2 ½ feet away, avoid glare, and keep the screen clean.

• Use a monitor that holds a steady image without flickering. Look for a dot pitch no greater than .28 mm and a refresh rate of at least 72 Hz.

Ergonomics and Health Issues - Eyestrain

• Take frequent breaks away from the computer.

• Sit at arm's length from the system unit and monitor.

• Use a flat-panel display (which does not produce EMFs).

Electromagnetic fields (EMFs) occur during the generation, transmission, and use of low-frequency electrical power. Some people are concerned that EMFs are linked to cancer.

To reduce your risks from EMF exposure:

Ergonomics and Health Issues -Electromagnetic Fields

• Junk Faxes and E-Mail

• Beating Spammers at Their Own Game

• Privacy Issues Facing Corporate Computer Users

Privacy Issues

• Junk faxes are unsolicited messages received from unnamed senders. Because they consume the recipient's resources, junk faxes have been outlawed.

• Junk e-mail (spam) is any uninvited e-mail message, but spam usually is commercial in nature and is delivered to many users at one time.

• Using a technique called spoofing, the spammer sends messages but hides his or her identity so the recipients cannot respond.

Privacy Issues - Junk Faxes and E-Mail

• Spam can cost businesses due to lost productivity. It can be annoying to individual users who must deal with junk messages.

• One way to fight spammers is to read your ISP's appropriate use policy and to report spam to your ISP and to the sender's ISP, if possible.

• You can also block messages from certain senders and domains, and use spam-blocking software provided by your ISP or a third party.

• You can reduce junk mail by not adding your name to mailing lists, and by making sure your credit records do not fall into the wrong hands.

Privacy Issues –Beating Spammers at Their Own Game

• Protect trade secrets.

• Prevent the distribution of libelous messages.

• Prevent users from downloading inappropriate materials.

• Ensure that resources are not wasted.

A business owns its computer systems and the data they contain. Businesses are entitled to restrict the use of their systems, to inspect them, and to block employees from any or all services.

Businesses commonly monitor the use of their systems to:

Privacy Issues -Privacy Issues & Corporate Computer Users

• Define ergonomics and list four health risks related to computer use.

• Define spamming and spoofing and explain how they affect computer users.

• Name three normal activities that result in a threat to personal privacy.

• List four reasons why a business may monitor employees' use of its systems.


Computing Issues that Affect Us All

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• Computer Crime

• Computer Viruses

• Theft

• Computers and the Environment

Computer Crime

• Software Piracy

• Protections from Piracy

• Software piracy – the illegal copying of software programs – is the biggest legal issue affecting the computer industry.

• Piracy is of greatest concern to developers of commercial software, or programs that must be purchased before using.

• Piracy is less of a concern for shareware makers, whose programs must be registered but not always purchased.

• Piracy is not a concern for freeware, which is software that can be freely distributed by anyone.

Computer Crime - Software Piracy

Computer Crime - Protections from Piracy

Various forms of copy protection have been used to discourage piracy, including:

• Installation diskettes that record the number of times the software is installed.

• Hardware locks, without which the program cannot function.

• Passwords, serial numbers, or other codes required for installation.

• Categories of Viruses

• Preventing Infection

Computer Viruses

Boot sector viruses Self-encrypting virusesCluster viruses Self-changing virusesFile-infecting viruses Stealth virusesWorms Macro virusesBombs Joke programsTrojan Horses Bimodal virusesPolymorphic viruses Bipartite virusesSelf-garbling viruses Multipartite virusesE-mail viruses Macro viruses

A virus is a parasitic program that infects another program (the host). Most viruses fall into the following categories:

Computer Viruses - Categories of Viruses

Computer Viruses - Preventing InfectionViruses are spread in several ways. The most common are:

• Treat all disks as though they are infected.• Install an antivirus program and keep its virus

definitions (database of virus information) up to date. • Run your antivirus program regularly.

• Receiving an infected disk.• Downloading an infected executable file from a

network or the Internet.• Copying a document file that is infected with a

macro virus.

To avoid viruses, you should:

Theft

• Hardware and Software Theft

• Data Theft

• Protecting Networks

Theft - Hardware and Software Theft

• As PCs become smaller – and as more people use laptop and handheld computers – hardware theft is becoming a growing problem.

• Software theft is also a major problem for companies, many of which must purchase large quantities of expensive software programs.

• To combat hardware and software theft, many companies are locking hardware to desks and securing software in libraries, granting access to employees only as needed.

• Data theft can be far more serious than software or hardware losses, because data can be difficult or impossible to replace.

• Hackers are a threat to sensitive corporate and government data because they pride themselves on getting around security measures.

• Organizations can keep hackers at bay by protecting their networks. This can be done by enforcing the use of user IDs and passwords.

• Data can also be protected through encryption, making it useless to anyone who does not have the encryption key.

Theft - Data Theft

Computers and the Environment

• Planned Obsolescence

• Use of Power

Computers and the Environment -Planned Obsolescence

• Because hardware and software products become obsolete after a given time, older systems are disposed of in large numbers.

• Large-scale disposals add to the clogging of landfills and pollution.

• To reduce these problems, organizations can download software from the Internet (reducing the number of disks and manuals used). Hardware can be recycled or donated to charities or schools.

Computers and the Environment -Use of Power

• Many people leave their computers running continuously, whether in use or not. This consumes power unnecessarily.

• To solve this problem, you can use a "green PC," which automatically powers down the monitor and hard drive after a period of non-use.

• Another way to conserve energy is to use hardware that conforms to the EPA's "Energy Star" program, which sets standards for power consumption.

• Define software piracy and explain why it is illegal.

• Name two ways in which computer viruses can be spread.

• Describe two methods used to protect networks from hackers.
