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Chapter 1 Review Review the Terminology DIRECTIONS Match each vocabulary term in the.left column with the correct definition in the right column input bit byte output hardware central processing unit random access memory peripheral software utility software program that tells the computer what to do group of 8 bits area where data and instructions are stored while the computer is working physical parts of a computer raw data entered into a computer program that does maintenance or repair tasks part of a computer that processes data basic unit of data a digital computer can understand hardware separate but connected to the computer the results of the computer’s processing Use the Terminology DIRECTIONS Complete each sentence with information from the.chapter A is a connection between a computer and a device. A is about 1,000 gigabytes. is the most common networking technology used for local area networks (LANs). Many devices such as keyboards, printers, and mice use ports. ports move data one bit at a time. For example, they connect computers to modems for internet access. ports move data in groups. ports accept a connector with 19 wires—ten on one side and nine on the other. Pink or red indicates a line-in port that connects the sound card to a. A port is shaped like a capital letter D and accepts a 25-pin parallel connector. is used for communicating between devices that are less than 30 feet apart. is a wireless technology used for connecting to the internet..Knowing some basic techniques can help you keep your computer running properly.Think Critically DIRECTIONS Answer the following questions How do analog and digital computers differ? Explain the difference between Wi-Fi and Bluetooth technologies. What are the differences between primary and secondary storage? What is the difference between system software and application software? Give at least one example of each. You purchased a new game for your computer that lets you play online with other people. You install the software but the feature for playing online won’t work. What ?might be the problem.Extend Your Knowledge DIRECTIONS Choose and complete one of the following projects Look at a computer. Create a five-column chart. In the first column, list all the hardware that you can identify. In the remaining columns, state whether each item is used for inputting, processing, outputting, or storage. Examine how the different pieces are connected to the computer. What other hardware do you think the computer has that you cannot see? With your teacher’s permission, unplug and replug all of the computer components, including external drives, a printer, mouse, keyboard, monitor, projector, and the power supply. Start the system. Locate the system specifications and add them to your column chart. Record your observations. Discuss your findings with the class. Using the internet or library resources, research at least three types of processing devices used in laptop computers. Keep track of your sources. Create a chart that compares and contrasts the price, top speed, and number of operations per second each one can perform. Determine which device would be most appropriate for working with text, graphics, and math. Write a brief summary explaining your findings, including a list of sources or bibliography. Read your summary out loud to a partner and listen as your partner reads his or hers out loud to you. With your :teacher’s permission, practice the steps for the following procedures Connect a wireless device to a computer. Connect a computer to a wireless network. Start a.computer in safe mode. Open the Task Manager on your computer IC3 Prep Which of the following are typical peripheral devices used with desktop computers? (Select ).all that apply CPU printer mouse keyboard.Match the port type on the left with its purpose on the right audio Ethernet parallel serial PS/2 DVI VGA HDMI USB the most common networking technology used for local area networks a standard connection interface that allows communication between computers and devices such as mice, printers, and smartphones an older interface once used for connecting input devices such as a keyboard or a mouse a digital cable standard for audio and video transmission found on most HD television sets an interface used to connect a monitor or other display device to a computer a bidirectional interface once commonly used for connecting devices such as a modem an older interface used to connect any type of display device to a computer color-coded mini jacks used for microphones and headphones an interface used to transfer multiple bits of data at the same time, which was once the most common way to connect a printer to a computer ).Which of the following are likely caused by hardware problems? (Select all that apply monitor is blank application will not open pointer does not respond to mouse keyboard does not respond to typing web page will not load in browser.Match the troubleshooting term on the left with its definition on the right error message knowledge base reboot hard reboot soft reboot safe mode malware update device driver compatibility restore point starting a computer with only a limited set of files and drivers turning off all power to the computer by pushing the power button or disconnecting the power cord programs designed to damage your computer system information displayed by your computer when something happens to prevent a command from executing turning the computer off and then on again a collection of information about a specific topic using the computer’s own software to allow your computer to shut down properly programs that enable peripherals to communicate with hardware the configuration in effect at a specific date or time able to work together software that fixes errors, compatibility, or security problems ).Which of the following might help you solve a network problem? (Select all that apply reset the router or modem defragment your hard drive clear your browser history check and correct your sync settings reformat your hard drive The accelerates the ability of the CPU to render 3D graphics. is a networking technology used for communicating between devices that are less than 30 feet apart. is a networking technology with signals that can reach up to 300 feet, usually used to connect to the internet. For the line below, select whether the statement is True or False. A CAT5 Ethernet cable performs faster and more efficiently than a CAT7 Ethernet cable. Which of the following is a ).typical system specification? (Select all that apply font color device model number operating system version file size Procedure Prep DIRECTIONS Familiarize yourself with these procedures to prepare for the.IC3 exams Starting the Computer Shutting Down the Computer Restarting the Computer Logging in to a User Account Synchronizing Files between Devices Using Microsoft OneDrive Connecting to a Wireless Network Connecting a Printer to a Wireless Network Starting a Computer in Safe Mode Opening the Task Manager on a Computer Using Device Manager to Update Drivers Reinstalling a Device Driver Creating a Restore Point with Windows Reverting to a Restore Point with Windows Installing a Program Uninstalling a Program Repairing a Program Creating a System Repair Disc Displaying System Information Verifying Network Connectivity Resetting a Computer to factory settings Connecting Peripherals to a Computer or Device LESSON 1-1 What Is a Computer? OBJECTIVES Describe the four operations of computers. Contrast analog and digital computers. Explain why data and instructions for computers are coded as 0s and 1s. Explain the hexadecimal.system of displaying color AS YOU READ SEQUENCE INFORMATION Use a sequence chart to help you organize the.four operations of computers as you read the lesson TERMINOLOGY bit byte computer data hexadecimal value input internet memory output processing program storage Computer Basics A computer is a machine that changes information from one form into another by performing four basic actions. Those actions are input, processing, output, and storage. Together, these actions make up the information processing cycle. By following a set of instructions, called a program, the computer turns raw data into organized information that people can use. Creation of usable information is the primary benefit of computer :technology. There are two kinds of computers Analog computers measure data on a scale with many values. Think of the scales on a mercury thermometer or on the gas gauge of a car. Digital computers work with data that has a fixed value. They use data in digital, or number, form. The computers that run programs for playing games or searching the internet, a global network of computers, are.digital computers Input Input is the raw information, or data, that is entered into a computer. This data can be as simple as letters and numbers or as complex as color photographs, videos, or songs. You.input data by using a device such as a keyboard or digital camera Bits of Data Data is entered into a computer in a coded language. The building blocks of that language are units called bits. Bit is short for binary digit. Each bit is a number, or a digit. A.bit can have only two possible values—0 or 1 Bits into Bytes Every letter, number, or picture is entered into the computer as a combination of bits, or 0s and 1s. The bits are combined into groups of eight or more. Each group is called a byte. Each letter or number has a unique combination of bits. For instance, on most personal computers, the letter A is coded as 01000001. The number 1 is 00110001. Even images are formed by combinations of bytes. Those combinations tell the computer what.colors to display and where to put them Hexadecimal Values Color can be represented by a three-byte combination where each byte represents the red, green, or blue (RGB) component of the displayed color. The intensity of each component is measured on a scale from 0 to 256, since there are 256 possible combinations of 1 or 0 in each group of eight bits. To represent a color, the three-byte RGB codes are simplified into a 6-digit hexadecimal value where the first two digits represent the intensity of red, the second two are green, and the last two are blue. A hexadecimal number has sixteen possible values, so the RGB values are assigned a number from 0 to 15. But since 10 through 15 are two digit numbers they are expressed with the letters A through F, where A equals 10 and F equals 15. In this way, the 256 possible combinations of each byte can be expressed in two digits. For example, the hexadecimal value for pure, intense red is FF0000 since red has the highest intensity and both green and blue are at zero. The hexadecimal for white is FFFFFF, or complete intensity of all three colors, and black is 0000000. Figure 1.1.1 Each computer component plays a role in one of the system’s four.primary functions CONNECTIONS MATH You ordinarily count using the decimal, or base 10, system. That system has 10 values, 0 through 9. You can express many numbers using those values by adding additional places—the 10s, the 100s, and so on. Each place is 10 times larger than the previous place. In a binary system, the quantity represented by each place is 2 times the previous quantity. In an 8-digit binary number, the places are the 1s, 2s, 4s, 8s, 16s, 32s, 64s, and 128s. The hexadecimal system is a base 16 system. The places for RGB code are the 1s and 16s. In the conversion from binary to hexadecimal, the first hexadecimal value is.equal to the 1s, 2s, 4s, and 8s of the color’s binary number Processing The second step of the information processing cycle is called processing. In this.step, the computer carries out a task using the data Coded Instructions What the computer does depends on the instructions, or program, given to the computer. The instructions are also written in binary code, using combinations of 0s and 1s. They might tell the computer to add two numbers, or they might have the computer.compare two numbers to see which is larger Speed of Processing Computers can process data very rapidly, performing millions of operations every second. The ability to process data with lightning speed is another reason computers are so valuable. TECHNOLOGY@SCHOOL In some schools, students’ work is collected over the year in electronic portfolios. These portfolios reflect a range of the students’ work on many projects during the school year. The computer’s ability to store this.information is perfect for portfolio work THINK ABOUT IT! Think about how an electronic portfolio might be used. Which items below ?do you think could be in an electronic portfolio multimedia presentations maps paper-and-pencil homework poetry lab report REAL-WORLD TECH ROBOTS AT WORK Some output is very unusual. Computer-controlled robots work in some auto factories. Their output is cars. The robots are perfect for the tasks that take place on an assembly line. These tasks are done over and.over again without change. For instance, robots weld parts together and paint car bodies NATALIYA HORA/SHUTTERSTOCK What is a disadvantage to workers of bringing in robots to do tasks such as factory work? ?What can businesses and workers do to make that less of a problem Output The third step, output, is the result of the computer’s processing presented to the user. If the program tells the computer to add two numbers, the output stage displays the result. To create output, the computer takes the bytes and turns them back into a form you can understand, such as an image on the screen, a sound through a speaker, or a printed.document Storage The fourth operation is storage, which is the action by which a computer saves information. Without storage, all the work you do on the computer would be lost. Computers have temporary memory chips used to store data during the processing stage. When the computer is turned off, however, any data in that temporary memory is lost. By storing the data in a permanent form on a device such as a hard drive, you can access the information over and over. This is another great advantage of computers—what you do one day can be saved and reused on another day LESSON 1-3 What Is Computer Software? OBJECTIVES Explain the difference between system and application software. Describe what an operating system does. Explain what utility software does. Identify four types of application software.and ways to obtain them AS YOU READ CLASSIFY INFORMATION Use a concept web to help you classify different.types of computer software as you read TERMINOLOGY application software apps download operating system (OS) software system software utility software Figure 1.3.1 Operating systems that run on computers, tablets, and smartphones are.examples of system software BLOOMICON/SHUTTERSTOCK What Is Software? Hardware includes all the physical pieces that make up a computer. However, hardware is useless without software. Software includes all of the programs that tell a computer what to do and how to do it. Think of a computer as a sports team. Hardware is the players, and software is the coach. No matter how talented the players are, the team.will only perform properly if the coach gives it the right instructions Types of Software Software is divided into two main types: system software and application software. System software includes programs that help the computer work properly. You are probably more familiar with application software, which are programs designed to help you do tasks such as writing a paper or making a graph. This type of software also includes programs that allow you to use the computer to listen to music or play games. DID YOU KNOW? One key to processor speed is its clock speed, the rhythm at which the processor works. Clock speed is measured in hertz (Hz). A Hz is a unit of frequency equal to one cycle per second. Most processor clock speeds are measured in Gigahertz (GHz). 1 GHz equals one billion cycles per second. Clock speed is not the only thing to consider when you select a processor, however. Speed is also influenced by factors such as the amount of RAM, clock.speed of the RAM, and the size of the cache System Software There are two types of system software: operating systems and system.utilities. Both help computers run smoothly Operating Systems The operating system (OS) lets the hardware devices communicate with one another and keeps them running efficiently. It also supports the hardware when applications programs are running. The two most widely used operating systems are macOS and Microsoft® Windows®. Google’s Chrome OS is the operating system used on.Chromebooks System Utilities Programs that help the computer work properly are called utility software. They usually do maintenance and repair jobs that the operating system cannot do itself. Some utility programs repair damaged data files or save files in certain ways so they take up less space. Others translate files created in one OS so they can be read and worked on in.another Application Software There are many different applications that people use at home, at work, :and at school. Some examples include Productivity software, which helps people be more productive at work. People use these programs to write reports, prepare financial plans, and organize data. Graphics software makes it possible to draw, paint, and touch up photos. Communication software allows computers to connect to the internet so people can send email or messages, video chat, or participate in meetings, classes, and conferences. Entertainment software lets people play.games, watch movies, listen to music, read, and generally have fun Custom Software Some organizations need software programs to do very specific jobs. They hire people to write custom software designed to do those jobs. Because these programs.are custom written, they are usually quite expensive Off-The-Shelf Software Most people use software to do standard jobs. They might want to write letters or organize an album of photos. They can choose from many ready-made programs to handle these common tasks. These are called “off-the-shelf” programs because stores and companies that sell software online stock them. Most off-the-shelf software purchased online can be downloaded directly onto the buyer’s computer. Because software.publishers can sell many copies of this software, it is less expensive than custom software Apps The term app is an abbreviation for the term “application,” usually used for programs developed specifically for smartphones, tablet computers, and other handheld devices. Apps are purchased from app stores, which are online portals where you select and download the programs. Basic versions of these apps are often free, although premium apps offering more features may cost anywhere from $0.99 to more than $200.00. Figure 1.3.2 You can.download apps from an app store such as Google Play MICROSOFT CORPORATION TECHNOLOGY@WORK A software program’s version is usually indicated by a number, such as “Version 4” or “Version 8.5.” Software is upgraded to remove programming errors and to add new features. Some revisions are major, and the version number jumps from, for example, 9.0 to 10.0. Minor fixes typically change the number after the decimal point, such.as 10 to 10.2 THINK ABOUT IT! For which items below would it be worthwhile for you to buy the new ?version of the program a program you use all the time that is moving from 4.3 to 5.0 a program you rarely use that is moving from 2.2 to 2.3 a program you often use that is moving from 5.1 to 5.2 a program you often use that is moving from 1.0 to 3.0 What Is Computer Hardware? OBJECTIVES Summarize how processing and memory work together. Contrast primary and secondary storage. Identify types of ports and connectors. Explain how to connect a variety of.peripherals to a computer. Describe how to connect using Wi-Fi AS YOU READ COMPARE AND CONTRAST Use an outline to help you compare and.contrast computer hardware as you read TERMINOLOGY Bluetooth® central processing unit (CPU) circuit circuit board cloud storage connector devices Digital Visual Interface (DVI) Ethernet graphics processing unit (GPU) hardware High-Definition Multimedia Interface (HDMI) IR wireless memory card optical storage device parallel port peripheral physical connection port proprietary random access memory (RAM) serial port Small Computer Systems Interface (SCSI) terabyte universal serial bus (USB) upload Video Graphics Array (VGA) volatile memory Wi-Fi wireless connection What Is Hardware? When you think about a computer, you probably picture its hardware, the computer’s physical parts. You use hardware devices to input data, turn raw data into usable.information, show output, and store data for later access Inside the Case Much of a computer’s hardware is hidden inside the computer case. Most of.this hardware is used for processing and storing data Processing Devices Perhaps the most important piece of hardware in a computer is the central processing unit, or CPU. This is the device that processes data. The CPU is a small, thin piece of silicon attached to a circuit board. The CPU is covered with tiny electrical circuits, or paths along which an electrical current is carried. By moving data along these circuits in specific ways, the CPU can do arithmetic and compare data very quickly. Another important processing device is the graphics processing unit, or GPU. The GPU accelerates the ability of the CPU to render 3D graphics. It is important for gaming and other multimedia applications, and is also used to improve artificial intelligence and virtual reality. IC3 ✓Define.processing devices.Figure 1.2.1 The CPU fits in a socket on a circuit board RMIKKA/SHUTTERSTOCK Primary Storage Some hardware used to store data is inside the computer case near the CPU. The computer uses random access memory, or RAM, to store data and instructions while the computer is working. In this way, the CPU can quickly find the data it works with. This type of storage is called primary storage. RAM is volatile memory, which means data in.RAM is lost when the computer is turned off Secondary Storage Devices Other pieces of storage hardware are secondary storage. The.following devices let you store data permanently—even when the computer is turned off Hard drives use a stack of disk platters to store large amounts of information permanently on the computer. External hard drives, which are plugged into the computer, are used to store backups of your data. They can be desktop or portable devices. They usually connect to the computer via a universal serial bus, or USB, port. A port is a connection between a computer and a device. Flash, jump, thumb, or pen drives—all names for the same kind of storage device—connect to the computer through a USB port. They hold anywhere from 4 gigabytes to more than a terabyte. (TB). A terabyte is about 1,000 gigabytes. A gigabyte (GB) is just over a billion bytes. Compact discs (CDs), digital video discs (DVDs), and Blu-ray Discs (BDs) are optical storage devices. You insert the CD or DVD into your computer through the disc drive. A CD can store 650 to 700 megabytes of data. DVDs can store anywhere from 4.7 gigabytes to double that amount if the DVD is double-sided. Blu-ray Discs hold from 25 gigabytes to 128 gigabytes. Cloud storage is online storage offered on various websites. Most of them will give you a few gigabytes for free, but then require you to pay for more space. Memory cards store data for mobile devices like smartphones and digital cameras..Some memory cards can store up to 2 terabytes Secondary Storage Capacity Hard disk drives hold the most data. Many computers now have hard drives that can store more than 4 terabytes. Some external hard drives can store more than 30 terabytes. Thumb or flash drives hold the next largest amount of data, sometimes going over a terabyte. CDs and DVDs hold the least amount of data—from around 700 megabytes to almost 10 gigabytes. A megabyte (MB) is just over a million bytes, but still several hundred of them on a DVD can store entire encyclopedias, including images,.maps, and sound CAREER CORNER SERVICE TECHNICIAN Computer hardware sometimes fails. When that happens, people call service technicians. These people work for computer companies. They might work in the offices of the company that employs them, or they might travel to business sites to fix machines. Technicians need to know about software and hardware because problems are sometimes caused by a computer’s programs and not by its.equipment Peripherals For most desktop systems, input devices, such as the keyboard and mouse, are separate from the case. So are output devices, such as monitors and printers. Hardware that is separate but can be connected to the case is called a peripheral. Printers, mice, and keyboards are typical peripheral devices that connect to desktop computers and laptops. Keyboards are also often used with tablets. Smartphones may connect as a device to a computer in order to transfer pictures or data files and they may also have peripherals of their own, such as a headset for hands-free use or speakers for playing music. Figure 1.2.2 Most computers feature a built-in hard drive. Some have capacities of 4 terabytes or more..Some external hard drives are able to store 30 terabytes of data GRANT TERRY/SHUTTERSTOCK Not all computers have all this equipment as peripherals. Apple’s iMac® computers include the monitor as a physical part of the main system. Other computers may have built-in storage devices. Portable computers, such as laptops, have the keyboard, a touchpad, and.a monitor all attached to the main unit Device Ports and Connectors Peripherals need to be connected to the computer so that data can be moved back and forth. Some use a wireless connection, such as radio waves, and some use a physical connection, such as a cable. Both wireless and physical connections require a plug, or connector. Most plugs join the computer at a port on the computer case, but some are installed internally. Connectors can be unique for the peripheral. Monitors have specific plugs designed for transferring image data. Speakers and microphones have unique plugs as well. Many devices, such as keyboards, printers, and mice, use USB ports. Some connectors are proprietary, which means they only work with devices made by the same manufacturer. Apple devices, for example, use proprietary connectors, like Lightning, to connect to a computer or power source. To connect a peripheral to a computer with a physical connection, identify the type of plug coming from the peripheral and locate the correct port on the computer. Attach the plug to the port and make sure the cable is secure at both the computer end and the peripheral end. IC3 ✓Identify cables, connectors, and.connections Each port is designed to accept a specific connector, so most connectors only fit into one type of port. That means you cannot plug a USB connector into an Ethernet port. Most ports.are labeled with icons to identify the type, and some are color-coded to match the connector Serial ports move data one bit at a time. For example, they connect computers to modems for internet access. Parallel ports move data in groups. Multiple device ports, such as Small Computer Systems Interface (SCSI) and Universal Serial Bus (USB) ports, connect several.peripherals to a computer at one time. They all move data faster than serial ports can Ethernet Ports and Connectors Ethernet is the most common networking technology used for local area networks (LANs). To create the network, Ethernet cables plug into Ethernet ports on computers, LANs, and cable or DSL modems. An Ethernet port is usually labeled with an icon similar to the one on the right in Figure 1.2.3. The cables are all copper twisted pair, but operate at different speeds and frequencies, designated by the category (CAT) number. CAT5 and CAT5e are still common, but CAT6, CAT7, and even CAT8 are available. The higher the number, the better the performance. Figure 1.2.3 Ports are usually labeled,.making it easy to know what plugs in where HFNG/SHUTTERSTOCK USB Ports and Connectors Universal Serial Bus (USB) is a standard connection interface that allows communication between personal computers and electronic devices. Almost all devices now can use a USB port, including printers, keyboards, mice, storage devices, cameras, smartphones, and fitness trackers. USB lets devices draw power from the connection so it can be used for charging. Adapters let you connect a USB port to A/C power. A USB port is usually labeled with an icon similar to the one on the left in Figure 1.2.3. There are different versions of USB ports. The oldest is USB 1.0; USB 4.0 was introduced in 2019. There are also mini and micro USB ports, which are used for many.mobile devices Video Ports and Connections There are three basic types of video ports and connectors,.with HDMI being the most common High-Definition Multimedia Interface (HDMI) is a digital cable standard for audio and video transmission. HDMI ports accept a connector with 19 wires—ten on one side and nine on the other. HDMI is found on most high-definition (HD) television sets, newer computers, projectors, Blu-ray players, and television devices such as Apple TV. HDMI cables can stream digital video and audio at the same time. Digital Visual (or Video) Interface (DVI) ports are used to connect a monitor or other display device to a computer. Most DVI connectors accept plugs with up to 24 pins. DVI with 24 pins supports 1920 x 1200 HD video. If there are fewer pins, it means it supports lower resolutions. DVI is video only; it does not support audio. Although DVI may be available on some computers, it is being replaced by HDMI. Video Graphics Array (VGA) is one of the oldest types of computer port. It was used to connect any type of display device to a computer, including monitors, projectors, and televisions. VGA is being replaced by DVI and HDMI but may still be available on some computers. A VGA port accepts a 15-pin connector. The pins are arranged in three rows with five pins on each row. The plug is often blue. VGA can support.resolutions up to 640 x 480 in 16 colors.Figure 1.2.4 Common video ports DRAGANA GERASIMOSKI/SHUTTERSTOCK Figure 1.2.4 Full Alternative Text Audio Ports and Connectors Many audio devices can connect to USB ports. Some computers have a 3.5 mm audio jack for connecting headphones and speakers. It is usually labeled with an icon of headphones. There are also dedicated audio ports called mini jacks.used for microphones and headphones. These ports are usually color-coded Pink or red indicates a line-in port that connects the sound card to a microphone. Green indicates a line-out port that connects the sound card to speakers or headphones. If there are orange and black line-out ports, they connect to surround sound speakers. The blue.line-in port may be used to connect a device that will play through your computer’s speakers Parallel Ports and Connectors A parallel port is usually the biggest port on a computer. It is shaped like a capital letter D and accepts a 25-pin parallel connector. Parallel ports can transfer multiple bits of data at the same time. Parallel ports were once the most common way to connect a printer to a computer. Now, most printers use USB connectors or are.wireless. Figure 1.2.5 Ports may be color-coded and labeled with icons Figure 1.2.5 Full Alternative Text Serial Ports and Connectors Serial ports, also called COM ports, were once the most basic connector available for devices such as a modem. Now, devices that once used a serial port use a USB port. A serial port transmits the 8 bits in a byte of data one at a time. Serial ports are bidirectional, which means they can accept data as well as transmit it. Serial ports accept serial plugs that usually have 9 pins. One row has five pins and a second row has.four. Some serial connectors have 25 pins PS/2 Ports and Connectors A PS/2 port used to be the port of choice for connecting input devices such as a keyboard or a mouse to a personal computer. Now these devices usually use USB ports. PS/2 ports are round, and accept a 6-pin plug. PS/2 ports may be.color-coded.Purple is used for connecting the keyboard. Green is used for connecting the mouse.IC3 ✓Distinguish between categories of data cables and connectors Wi-Fi and Bluetooth Connections Wi-Fi and Bluetooth are types of wireless technologies you can use to connect to devices and the internet. Bluetooth is used for communicating between devices that are less than 30 feet apart, while Wi-Fi is used for connecting to the internet. Wi-Fi signals can reach up to 300 feet. You might use Bluetooth to connect a wearable fitness tracker to a computer so you can upload your daily activity statistics, to send photos from your smartphone to a computer, or to connect your tablet to a wireless speaker. You might use Wi-Fi to print a file when you are using your tablet in a conference room and the printer is in your office on the other side of the building, or to access the internet when you are at a coffee shop. To set up or connect to a Wi-Fi network, the computer must have an internet connection, a modem, a router, and a wireless network adapter card. Bluetooth devices have built-in radio transmitters and receivers that enable wireless communication. Operating systems today make it easy to establish Wi-Fi or Bluetooth communications. For example, in the Settings utility for Windows you can choose to add a Bluetooth or other type of wireless device. Windows prompts you through the steps to make the connection. To set up a Wi-Fi network in Windows, you set up a new network from the Network and Sharing Center. Windows prompts you through the necessary steps..IC3 ✓Compare and contrast network and connection types IR Wireless One of the earlier wireless technologies that allowed computers to exchange data is called IR Wireless. It uses infrared radiation to transmit data. Infrared is electromagnetic energy at a wavelength slightly longer than that of red light. Some older notebook computers and handheld personal devices were equipped with infrared adapters, and had IR ports on the back or side. The infrared signals cannot penetrate walls, so IR devices have to be in the same room, within a few feet of each other to exchange data. This may seem like an inconvenience, but it provides security during the transmission. Although IR Wireless has been replaced by the faster and more reliable Wi-Fi and Bluetooth technologies for data transfer, it is still used for other purposes, including television remote controls, home-entertainment control units, intrusion detectors, robot control systems, cordless microphones, and headsets. Figure 1.2.6 Windows includes a Settings utility for connecting a wireless device to a computer LESSON 1-4 What Is Troubleshooting? OBJECTIVES Explain basic problem-solving techniques. Describe how to determine if a problem involves.hardware or software. Use proper terminology to describe problems AS YOU READ IDENTIFY KEY POINTS As you read, use a conclusion chart to help you.identify key points about troubleshooting TERMINOLOGY compatibility default factory settings device driver error message firmware full system restore hard reboot knowledge base malware platform product agnostic reboot reformat restore restore point safe mode soft reboot system specifications troubleshooting update virus Troubleshooting Troubleshooting is the act of diagnosing and, hopefully, solving a problem. Knowing some basic problem-solving, or troubleshooting, techniques can help you keep your computer running properly. Before you begin troubleshooting, you will have to diagnose what type of problem your computer is experiencing. A good first step is to determine.whether the problem involves hardware, software, or networking If you are having trouble opening an application, programs are running slowly, or the computer is crashing or turning off unexpectedly while you are working, the problem is most likely with the software. If the monitor will not display an image or the pointer is not responding to the mouse movement, the problem is most likely with your hardware. Because the device hardware depends on software, sometimes the problem is with both the hardware and the software. If you cannot load a web page in your browser, save a file to a network or cloud drive, or print on a network printer, the problem is most likely with your network or.internet connection.IC3 ✓Identify basic troubleshooting steps There will always be some trial and error involved in troubleshooting while you determine the specific problem. It is a good idea to write down the steps you take so you can recreate them, and also write down any error messages displayed by your system. An error message is information displayed by your computer when something happens to prevent a command from executing, such as no communication between the processor and a device or a.problem with the software code Basic Hardware Troubleshooting Sometimes your hardware devices may experience problems. They may stop working or stop responding to commands. Hardware does wear out, so you may have to replace older, broken components, but you also may be able to use.troubleshooting techniques to diagnose and solve hardware problems Cables and Connections Many hardware problems occur when cables or wires become loose. When your monitor goes dark or your keyboard won’t respond, turn the system off and check to make sure all cables are securely connected. Many computers are plugged into a power strip. Make sure the power strip is on. When you have reestablished all.connections, turn your system back on and see if the problem is resolved Reboot Many computer problems—such as a program freezing—can be solved by a simple reboot. When you reboot your computer, you turn it off and then on again. There are two kinds of reboots: A hard reboot is when you turn off all power by pushing the power button or unplugging your computer. A soft reboot is when you use the computer’s own software to allow your computer to shut down properly. You can select the main menu and choose “shut down” or “restart.” Figure 1.4.1 Tightening cables and connections can solve many basic.hardware problems AUREMAR/123RF.COM Basic Software Troubleshooting Most of the time your software programs will respond to your commands as intended. Sometimes there will be problems. Programs might seem slow or sluggish, applications might freeze in the middle of an important task, or you might not be.able to launch an application at all Platform Considerations A computing platform is the hardware, operating system, and firmware on which programs run. Firmware is the software that provides basic instructions for controlling devices. Problems may occur if there is not compatibility between the programs and the platform. Compatibility is the ability of things to work together. If they are not compatible, they cannot work together. Another term used for compatibility is product agnostic. A platform-agnostic program can run on any platform; a software-agnostic program can read and exchange data in any format. Some software is only designed to run on certain operating systems. For example, you might have a game that can only run on a PC with Windows OS and will be unable to run on Macintosh or Linux systems. You might have a mobile device running Apple’s iOS, which means you cannot run an app designed for a device that runs the Android operating system. Documents and media files, such as videos or audio, can only be opened with certain programs. If you have media that won’t play, you probably don’t have the correct software on your computer. Likewise, a game might not run on your computer if your system is not compatible with the program. Checking the application and system requirements of programs will allow you to verify that your platform meets the minimum operating criteria for the software. Some software also requires specific hardware devices to run properly. For example, a device may require a connection to the internet in order to run an application. If the device is not hard wired through an Ethernet.port, or is not equipped with Wi-Fi, the software will not run Updates When manufacturers are aware of problems with software programs, they usually release an update. Updates are software that fix errors in the program as well as issues such as compatibility with hardware devices or security risks. Installing a software update may quickly resolve a problem. Companies usually make updates available to registered users free of charge. You can set your programs to automatically check for, download, and install updates, or to notify you when updates are available so you can download and install them manually. If installing an update does not solve a problem, you can try restoring the.program defaults or uninstalling and reinstalling the program Device Drivers Device drivers are the programs that enable peripherals and devices to communicate with the hardware through the operating system. If a device stops working, it may be because there is a problem with the driver. You can use a device management utility to check that the device is set up properly and that the driver software is installed and up-to-date. In Windows it is called Device Manager; on Mac systems, it is called Profile Manager. You can use these utilities to install or update the driver, rollback the driver to a.previous version, disable the driver, or uninstall and reinstall it Viruses and Malware Malware is a program designed to damage your system. A virus is a type of malware designed to spread through a computer system or network. If all programs are running slowly, you may have accidentally downloaded a virus or other malware program. Run a virus scanner to identify and remove dangerous programs. Always have.virus and malware detection software installed and up to date Disk Space The amount of storage space may seem like a hardware problem, but it will cause software to run slowly, and it will prevent you from saving your files or installing new programs. Your operating system has a utility to check the amount of used and available storage space. Another utility can recommend files to delete in order to free up additional space. In Windows, the program is called Disk Cleanup. It is found in the System settings. Another Windows utility, called Defragmenter, reorganizes the data stored on a hard disk to.make more space available Task and Process Management Most operating systems include a utility for monitoring tasks and processes currently running on your computer. On a Windows system, it is called Task Manager. You open it by pressing Ctrl + Alt + Delete and selecting Start Task Manager. On a Mac, it is called Activity Monitor. You open it from the Applications/Utilities folder. These programs show you the status of programs and processes currently running on your system. You can use them to start and end a program or process; enable or disable startup programs; and to identify and end processes that may be running in the background that you do not need. Figure 1.4.2 Use the Task Manager in Windows to start and end a program or.process MICROSOFT CORPORATION Figure 1.4.2 Full Alternative Text Safe Mode Most computers let you start in safe mode, which means they start with only a limited set of files and drivers, which are programs that allow the computer to communicate with devices such as printers and monitors. Safe mode lets you identify and fix problems with software that is interfering with the operating system and other components. You may.be able to choose to start in safe mode with or without internet access System Restore You can often use a utility to restore your system or personal device to the settings in effect before it stopped working. Windows comes with a Restore utility that automatically creates a restore point at specific intervals, such as each day when you start your system or when you install a new software program. You can also manually set a restore point. The restore point identifies the configuration settings in effect at a specific point in time. If there is a problem, you can use the utility to revert back to a restore point before the problem occurred. Changes to your system settings since the date and time of the restore point are undone, including new software installation or modified system settings. Your data files remain unchanged. Reverting to a restore point is not the same as restoring data that you have previously backed up. Using a restore point restores system settings; it does not affect data files. If data files have been lost or damaged, reverting to a restore point will not solve the problem. You must restore the files from a backup to make them available again. Another option is to use a system repair disk. With an operating system such as Windows, you can create a system repair disc or recovery drive that allows you to boot the computer and access troubleshooting tools. You may also be able to perform a full system restore to reset a device to the default factory settings, which are the settings the device is built with. This should be a last resort, as it usually involves deleting all data stored on the device and reinstalling the operating system. If you must revert to the default factory settings, you should always create a full system backup first so you can restore your data once the reset is complete. Similarly, if you reformat a hard disk, you erase all data from the disk. Reformatting sets up a file system so the operating system can read data to and write.data on a disk. In Windows, you use the Disk Management Utility to reformat a hard disk Basic Network and Internet Troubleshooting When you cannot connect to your home or business network or to the internet, you cannot access the information and resources stored online. Some of the troubleshooting for network problems are similar to the steps you take.for hardware or software problems Check and reconnect cables. Reset the router and/or modem. Power equipment off and then on again. Run a virus and malware scan. Clear your browser history. Log off and log back on. Check that your access credentials, such as user name and password are entered.correctly. Check that your sync settings are correct.IC3 ✓Describe basic network troubleshooting techniques Getting Help There are many methods of getting help for identifying and solving computer issues, including searching for information online, reading the documentation, using the.built-in Help program, and contacting a technical support service Documentation All your computer products—from your PC to your printer and software—come with product manuals. The manuals may be printed books but most likely they are available on the manufacturer’s website. These manuals will always have a troubleshooting section. Figure 1.4.3 Use a troubleshooter utility to diagnose and correct.computer problems MICROSOFT CORPORATION Figure 1.4.3 Full Alternative Text Help Programs Most software has a built-in Help program that provides information on how to use features and accomplish tasks. You can look in a table of contents or index or search the program for answers to specific questions. These Help programs often provide links to troubleshooter utilities that prompt you through a series of questions to diagnose a problem and offer suggestions for action you should take to correct the problem. For example, you can find Windows troubleshooters through the Control Panel. Open the Control Panel, and.then select Find and fix problems Technical Support You can often find answers to questions and solutions to problems through technical support. If the product is still under warranty, or you are a registered user, you can often get help from the manufacturer’s tech support team via email, through a knowledge base website, over the phone, or through an online live chat. A knowledge base is a collection of information about a specific topic. Most companies maintain a searchable knowledge base that is similar to a Help program. Other methods of obtaining technical support include online user forums and discussion groups where other users and product.experts share information Finding System Information When you need to search for or ask for troubleshooting assistance, it is important that you know your system specifications. System specifications, or specs, include things like the operating system version, the name and version of software programs or apps that are not working properly, and the make and model of your computer, CPU, and other devices. Most operating systems have a system settings page where you can find the specifications. For example, in Windows, search for Device Specifications and open the System Settings app. You might also check the Device Manager. On a Mac, choose the Apple menu and then choose About this Mac. IC3 ✓Obtain system information.to support troubleshooting Understanding Computers GEORGE RUDY/SHUTTERSTOCK Chapter Outline LESSON 2-1 EXPLORING COMPUTER SYSTEMS LESSON 2-2 BASIC PROGRAMMING CONCEPTS LESSON 2-3 GROUP AND INDIVIDUAL COMPUTING LESSON 2-4 MOBILE DEVICES LESSON 2-5 INTERNET CONNECTIONS Working Together Computers come in many different shapes and sizes. Some are large enough to fill a room. Others can be held in the palm of your hand. Whatever their size and capabilities, all these computers have something in common. They use electronic parts and instructions to perform specific tasks. The electronic parts or components are called hardware. Hardware includes things like computer chips, circuit boards, hard drives, keyboards, monitors, and speakers. These hardware pieces, however, cannot perform the tasks by themselves. They require power and instructions. Electricity provides the power and software provides the instructions to work. Software programs unlock the potential of the hardware so that you can use the computer to do amazing things. LESSON 2-1 Exploring Computer Systems OBJECTIVES Explain how input devices are suited to certain kinds of data. Distinguish between RAM and ROM. Explain how memory, storage, and processing speed impact usage. Identify an appropriate output device for different types of data. Explain Ohm’s Law and its effect on electricity in a circuit. Summarize the tasks of operating systems. Identify two leading.operating systems and explain why compatibility is an issue AS YOU READ IDENTIFY INFORMATION Use an outline to help you organize details about.devices used to perform computing functions as you read the lesson TERMINOLOGY alternating current (AC) circuit command computer system current direct current (DC) flash drives font handwriting-recognition software memory speed motherboard multicore processor Ohm’s Law read-only memory (ROM) resistance screen-magnifier software speech-recognition software stylus transformer transistors touchscreen virtual memory voltage Parts Make a Whole It takes many different parts working together for a computer to do its job. A computer system includes several devices that perform the four basic functions of.computing: input, processing, output, and storage Input Devices Input means entering data, such as text, images, or sounds. Computer users.can choose from several different input devices Text and Commands Perhaps the most basic input device is the keyboard. You can type on it to input text (letters, numbers, and symbols) and commands. Keyboards may be localized for a specific language, such as Arabic or Chinese. A command is an instruction for the computer to perform some action. For example, the Print command tells the computer to send the file you are working on to a printer. With speech-recognition software, users can input text by speaking into a microphone, and with handwriting-recognition software, users can input text by writing with a stylus directly on a device such as a tablet or screen. The software changes the words into digital data the computer can read. This software can be used by people with disabilities that prevent them from typing. A mouse moves a pointer on the monitor, which allows you to move around a document, or to select commands. Some individuals cannot use a mouse. For them, keyboard equivalents for mouse commands provide access to the data. Adaptive devices can help users type without using their fingers on the keyboard. A trackball, touchpad, or trackpad function similarly to a mouse. A touchscreen lets you input some commands by touching the monitor directly. There are also motion-recognition software programs that let you input some commands by moving your hand across the display or by looking at a location on the screen. A joystick, often used in.computer games, is yet another input device Images A mouse or stylus can also be used to input images by drawing in a graphics program. You can also input images using a digital camera or scanner, by importing them.from a storage device or smartphone, or by downloading them from the internet Sounds Microphones can be used to input sounds. As with images, sounds stored on a storage device or on the internet can also be entered into the computer as input. TECHNOLOGY@HOME A sudden loss of power that shuts down a computer may result in the loss of unsaved work. Users can prevent that loss by buying a backup device that runs a battery if the power shuts down. The battery can keep the computer running for 20 to 45.minutes, which gives the user enough time to save valuable data THINK ABOUT IT! Think about what would be harmed by a loss of power. Which kinds of ?data listed below would suffer from a loss of power data on a hard drive data on a DVD unsaved data in RAM data in ROM data on a cloud server Processing Devices Inside the computer, data travels from one device to another through the computer’s motherboard. This board is covered with electrical circuits and switches, and it.connects vital pieces of hardware such as the CPU and memory The CPU The main processing device in a computer is the central processing unit, or CPU. The CPU is a chip that receives data from input devices and changes it into a form that you can use, such as text, pictures, or sounds. The processor also follows your commands to do something to that data, such as change a word or move a picture. CPUs can carry out fewer than 1,000 instructions. However, they can perform millions of these operations every.second. That ability is what makes computers able to work so quickly Multicore Processors Multicore processors have two or more CPUs so they can process data faster. Most personal computers have at least a dual core processor (two CPUs), and some have quad core processors (four CPUs). The more cores on the CPU, the higher the.price. But, the improved processing speed may be worth it RAM The CPU temporarily stores the instructions and data it is using on chips called random access memory, or RAM. Once the computer is turned off, RAM no longer stores any data. Reading information from RAM takes very little time—just billionths of a second. Because programs today are complex, they need a large amount of RAM to run properly. The amount of time that it takes RAM to receive a request from the processor and then read or write data.is called memory speed. Like CPU processing speed, RAM speed is measured in MHz ROM A second kind of memory is called read-only memory, or ROM. These chips contain the instructions that start the computer when you turn it on. The instructions in ROM typically.do not change once this memory is placed on the motherboard CPU vs. Ram vs. Hard Disk Factors that impact computer performance include processing speed, memory speed and size, and storage device speed and size. Most important, however, is how well these three components work together. Even if you have the fastest, most efficient CPU available, it cannot process data quickly if there is not enough RAM available, or if the RAM speed is too slow. If there is not enough RAM to hold the data, the CPU uses virtual memory. Virtual memory is actually storage space on the hard disk that can function as memory when needed. The problem is that when the CPU needs virtual memory, it must keep accessing the disk. As a result, the computer can only perform as fast as the.disk drive. IC3 ✓Describe concepts related to memory Figure 2.1.1 The motherboard houses all the chips and circuits a computer needs in order to.function ANDREYBRUSOV/SHUTTERSTOCK Output Devices Output is the results of the computer’s processing. The output that users see or hear can lead them to give the computer new instructions for processing their data. A computer needs output devices to display the results of its processing. Text and images are displayed on a computer screen. They can also be printed by a printer. Sound data is sent to speakers inside, or connected to, the computer. You can also connect headphones to a computer to listen to sounds. Some output devices and features help make computers more.accessible to users with disabilities Monitors Both text and images are displayed on the monitor. Screen-magnifier software can make images on the monitor much larger for people who have difficulty seeing. The program enlarges the area where the cursor is. The user can also change the colors on the monitor to.make text easier to see Printers Another form of output for text and images is print. A high-quality output at a large font size may help some people with poor vision read printed text more easily. A font is a specific typeface with a certain size and style that is used for characters in a document or on a screen. Braille printers can also provide output in a format some people with visual.disabilities can read Speakers and Headphones To hear recorded voices, sounds, and music, you need external speakers or headphones. Software lets you choose which recording to hear and adjust the volume. Windows has a feature called Show Sounds. When activated, this feature shows a visual symbol when it plays a sound and displays spoken words as text. This feature can help people who have hearing difficulties. Many programs can display audio as printed text so people with hearing difficulties can see the spoken words. Figure 2.1.2 Headphones let.you hear sounds output from the computer DIEGO CERVO/SHUTTERSTOCK Storage Devices Because memory is temporary, a computer needs a secondary location for storing data permanently. Devices such as hard disk drives, flash drives, CDs/DVDs, and online storage are all popular types of secondary storage. TECHNOLOGY@WORK Purchasing and maintaining a computer system is costly for both individuals and companies. It is important to research all available options to make sure the investment will pay off in.terms of productivity, ease of use, and efficiency THINK ABOUT IT! Although the decision-making process is similar for both individuals and companies, there are some differences. Rank the following factors in order from more important to less important for individuals and then for businesses. Are the rankings the ?same? Why or why not How much does it cost? Is it easy to use? Does it work with existing software and hardware? Does it meet current needs? Will it meet future needs? Is it expandable? Is it easy to ?maintain? Is it durable Electricity Powers the Computer All computer components are powered by electricity. When you plug the computer into an outlet, the electricity flows from the outlet to the circuits of the computer. A circuit is a network of electronic components. The computer circuits contain switches, or transistors, that use the electricity to complete tasks. But how does the electricity get to your house? Power companies send electricity from a power plant to your house through power lines. Before the electricity goes into your house it travels into a transformer, which is a device that transfers electricity from one circuit to another. Wires, called windings, in the transformer lower the voltage, or electric pressure, of the electricity before it reaches your house. The electricity flowing through your computer behaves in a constant fashion and follows scientific rules. Ohm’s Law is a rule that describes how electricity will behave as it travels through circuits. Ohm’s Law says that the current, or flow of electricity, through a wire is directly proportional to the voltage pushing electricity through the wire. Think of water moving through pipes. If you increase the pressure in the pipes, the water moves faster. Electricity acts in the same way. If you increase the voltage, the current moves faster. Electronics in your house do not use a constant flow of electricity, called direct current (DC). Instead, they use an alternating current (AC). With AC current, the electricity briefly travels in one direction and then reverses direction. The back and forth happens very rapidly: over 50 times a second! Computers plug into the same type of AC outlet that other appliances use, but once the current reaches the computer’s power supply it is converted to DC. That’s because the internal computer components require DC. Figure 2.1.3 In transistors, three terminals are connected to an external circuit. Altering the current in one terminal changes the current in the other two. Many transistors together make up the.integrated circuits used in modern electronics STUART ATTON/123RF.COM :CONNECTIONS MATH Ohm’s Law can be summarized in the math equation This equation states that the voltage (V) equals current (I) multiplied by resistance (R). If you had a constant voltage but increased the resistance, the current would decrease. The equation shows that there is a direct relationship between voltage and current and an inverse relationship between current and resistance. Because this relationship is constant, it is possible to adjust one variable within the circuit by controlling the other two. Give it a try: if you had a circuit with a voltage of 6 and a resistance of 2 what would the current be? The measurements for voltage is volts, resistance is ohms, and current is amps. Now what would ?happen if you kept the voltage at 6 volts but then changed the resistance to 3 ohms Ohm’s law also says that if there is more resistance in a wire, the current will move more slowly. Resistance is caused by anything that obstructs or inhibits current. Think about when you have a clog in your pipe: the water pressure is still the same but less water can flow through. There are many different types of conductors, or materials that electricity flows through, and each creates a different amount of resistance. Length and width of wires can affect resistance as well. Resistance can be added to a circuit by using different materials or changing the thickness of the wires. Devices that add resistance to a circuit are called resistors. Computers use the relationship between voltage, resistance, and current in a circuit to control either the voltage or the current through the different components. The total resistance of all resistors in a circuit depends on both their individual values and how they are connected. When resistors are in a series, or straight line, the current from the voltage source flows through them sequentially, or one after the other. So, the total resistance in the circuit is equal to the sum of the individual resistances. When resistors are placed parallel, with each resistor connected directly to the voltage source, each resistor gets the full voltage of the source. More current flows from the source, so the total resistance is lower. In fact, the total resistance in the circuit is equal to the sum of the inverse, or opposite, of each individual resistance. DID YOU KNOW? A digital multimeter (DMM) is a tool that can measure amps, volts, and ohms. It is used by technicians in most fields that involve electrical work, including the computer industry, because it can help diagnose electrical problems. In use, you connect the DIMM so it becomes part of the circuit, and the digital display shows.the selected measurement Software Controls the System Recall that the software that tells a computer how to do its :work is the operating system, or OS. The OS does many different jobs Working with peripherals: moving data and commands between the CPU and monitors, printers, and disk drives Managing data: finding the needed programs and files Using memory: storing data and programs in RAM or on the hard drive Coordinating data processing: doing many tasks at once without interfering with one another Providing the user interface: organizing and displaying the options you see on your screen when you turn on your computer Systems Compatibility The two most popular operating systems are Microsoft® Windows® and macOS. Both use text and images to represent data and programs. macOS runs on Apple® computers. For many years the two systems were not compatible, meaning that files saved in one OS had formats that could not be read by the other OS. Today, cross-platform compatibility, or the ability to use a file on any device no matter what operating system is being used, is important. Versions of many programs are written to run on many operating systems. For example, versions of Microsoft Office applications are available for PCs running Windows, Macs running macOS, mobile devices running iOS, Chromebooks running Chrome OS, and mobile devices running Android OS. Figure 2.1.4 Microsoft Office.applications available on the Start menu of a Windows computer MICROSOFT CORPORATION Figure 2.1.4 Full Alternative Text In addition, most programs include a Save As command that lets you save files in different formats, and an Open command that lets you open files saved in a different format. There are also utility programs that can translate files that previously may have been unreadable so they can be used on devices running a different OS. LESSON 2-2 Basic Programming Concepts OBJECTIVES Explain the binary system used by computers. Describe how software is written and translated. Explain why Boolean Algebra is used in computers. Explain the function of algorithms and how they are used in programming. Identify the three components of.structured programming AS YOU READ OUTLINE INFORMATION Use an outline as you read to help you organize.information about how software makes computers work TERMINOLOGY algorithm ASCII Boolean algebra character set compiler IF statements interpreter logic gate object object code object-oriented programming operator procedural programming programmer programming language source code subroutine Unicode Software Provides Directions How does a computer know what to do with data in digital form? Software gives it the instructions it needs. Experts called programmers write the instructions that become software. Programmers write these instructions, called source.code, using a programming language Types of Programming There are two basic categories of programming, procedural and object-oriented. Procedural programming uses step-by-step instructions to tell a computer what to do. Procedural programming languages include C, Fortran, Pascal, and Basic. Object-oriented programming provides rules for creating and managing objects, which are items that include both data and how to process the data. Object-oriented programming languages include Java, Alice, Python, and VBScript. Some programming combines the two. C++ is an example of a programming language that uses both procedural and.object-oriented programming Compilers and Interpreters Special programs called compilers translate the source code into binary form using only 0s and 1s. The result, called object code, can be read and acted on by a computer. Sometimes programs called interpreters are used to translate the source code directly into actions, bypassing the need for a compiler. Interpreters are able to immediately follow the instructions in the binary code while compilers must first wait and translate the binary. Even though the compilers take longer to get started, they are able to complete tasks much faster than interpreters. Figure 2.2.1 Programmers write the.instructions that tell a computer what to do ANDREY POPOV/SHUTTERSTOCK Representing Data Some programming languages require the programmer to assign a data type to variable data. Some common data types include string, which is a sequence of characters that does not contain numbers used for calculations; numeric, which is numbers or amounts that are used in calculations; character, which is text; integers, which represent.whole numbers; and date, which is the method of coding dates Digital Computing The computers widely used today are digital machines. Each piece of information used in the computer is identified by a distinct number. As a result, the computer acts on each piece of data by comparing its value to the value of other data or by performing.a mathematical operation on it The Binary World Most computers are not just digital but binary, too. That is, they only recognize two possible values. Think of a television’s power switch. It, too, is binary: The switch is either on or off. There are no other possibilities. Computers break data into pieces called bits and give each bit a value of either 0 or 1. A byte is a group of bits—usually 8. Using 8 bits in different combinations, each byte can represent a different value. For example, one byte might be 00000000, another might be 01010101, and another might be !00110011. There are 256 possible combinations Data in Bytes Every piece of data that a computer works on, therefore, must be expressed in 0s and 1s and organized into bytes. These bytes can alone represent characters and numbers or be taken in combination to express more complex instructions like displaying.color Digitizing Text Programmers use 0s and 1s arranged in 8-digit bytes to represent the letters of the alphabet and many standard punctuation marks. American Standard Code for Information Interchange (ASCII) is a common system, or character set, for coding letters that uses 8 bits. Unicode, which uses 16 bits, is another. TECH@HOME When you backup your data, you make copies of data stored on your computer’s hard drive to an external hard drive, USB flash drive, online storage service, or CDs/DVDs. Using an external hard drive with backup software or an online service lets you backup automatically. If you use.CDs/DVDs or flash drives, you must backup data on your own THINK ABOUT IT! Before deciding how to backup your hard drive, think about why it is important to backup. Sequence the importance of backing up each item in the list below :)using a scale of 1 (lowest) to 5 (highest a program you can download from the internet a report that you spent four hours on a file not used for a year photos of friends stored files of a game Programming Creates the Software The Language of Computers People communicate using words made up of 26 letters. Computers communicate using programs made up of two numbers—1s and 0s. No matter how complex, all computer tasks within a program are based on directions given in 1s and 0s. To write computer code, programmers use math called Boolean algebra. Boolean algebra only has two values: true and false. This form of algebra is perfect for programming because binary also has two values. While using Boolean math in programming, 1 is true and 0 is false. When you solve a math problem, you use an operation like addition or multiplication to find the relationship between two numbers. Boolean calculations are solved with the Boolean operators AND, OR, and NOT. These operators compare one or more Boolean values. When using the AND operator, if two values are true, then the solution is true; otherwise it is false. With the OR operator, if either of two values is true, then the solution is true. The OR operator is only false when both values are false. The NOT reverses a value from true to false. Computers use physical devices consisting of a group of switches called a logic gate to perform Boolean equations. Using a combination of logic gates, programs direct the computer to perform more complex functions like computing advanced math or playing a song from an audio file. DID YOU KNOW? Boolean operators are used outside of algebra as well. When you use a search engine to search for information online.you can use Boolean operators to fine-tune your search results If you search for George Washington AND the American Revolution, the search engine would display links to Washington’s efforts during the revolution. If you search for George Washington OR the Revolution, the list includes links about Washington and links about the Revolution. If you search for George Washington AND NOT the Revolution, the list includes.links to Washington’s life outside the American Revolution Charts called Truth Tables can be used as a quick reference to find the solutions to Boolean algebra problems. The values in the equation are X and Y. The solution is Z. For example, with the AND truth table, when X and Y equal 0, or false, then Z equals false. For the OR truth table only one variable needs to be true for the result to be true. Figure 2.2.2 Examples.)of an AND Boolean truth table (left) and an OR Boolean truth table (right Figure 2.2.2 Full Alternative Text Programs Are Directions Programs are a sequence of instructions that result in the computer performing a specific task. This linear sequence of instructions is called an algorithm. In a program, the algorithm is a designated sequence of calculations. The calculations are always done in the same order and steps are never skipped, so the result is always the same. Algorithms do not have to be a sequence of calculations. They can be a sequence of instructions that result in a predictable outcome, or solve a specific problem. When you bake a cake, the recipe is your algorithm. If you follow the recipe steps precisely and in the correct order, the result is a successful cake. Figure 2.2.3 Algorithms can be illustrated using a flowchart, which has boxes connected with arrows, showing the order of steps. This.flowchart shows the sequence of steps involved in following the steps in a cake recipe Figure 2.2.3 Full Alternative Text The Structure of a Program There are three main components in programs: sequence, decision, and loop. Programs follow the same linear sequence of actions every time they run. If a program is solving the equation 2(x + 1), it always adds 1 then multiplies by 2. If it performs the operations in a different order—say, multiplies by 2 and then adds 1—the answer would not be correct. The computer ends each action with a decision. The decision is the choice the program takes at the end of each step. The decisions are determined with IF statements. An IF statement defines conditions that must be met for the program to move to the next step. For example, IF you have finished adding the ingredients to the cake batter, then you can put the cake in the oven. Sometimes an action is repeated in a loop, or iteration, until a desired result occurs. You can illustrate the structure of an algorithm with a flowchart, using arrows to indicate the linear sequence, and the iterative loops. Some sequences are described in a single line of code called a subroutine. With a subroutine, a programmer can tell the computer to perform an entire sequence without having to type every step. DID YOU KNOW? Software is written in lines of code. Each line is an instruction or a comment. Operating-system software can take up a huge number of lines of code in :different machines. Here are some comparisons an ATM: 90,000 lines air traffic control: 800,000 lines Microsoft Windows 10: 50 million lines (estimated) all Internal Revenue Service programs: 100 million lines LESSON 2-3 Group and Individual Computing OBJECTIVES Understand common hardware configurations. Compare and contrast different kinds of computers used in organizations. Compare and contrast different kinds of computers used.by individuals AS YOU READ COMPARE AND CONTRAST Use a Venn diagram to help you compare and.contrast information about the types of computers as you read the lesson TERMINOLOGY computer configuration desktop computer emerging technology evolving technology handheld computer laptop mainframe notebook server smartphone supercomputer tablet computer workstation A Dizzying Variety Computers are available in a wide range of configurations, from huge machines as big as a room to devices so small they can fit in your pocket. A computer configuration refers to the hardware, software, and peripherals that comprise the computer. It includes memory, storage, processor, and both internal and external devices. Computers are usually configured based on the tasks for which they will be used and the environment where they will be used. Each type of computer is suited to handling a particular set of jobs in a particular setting. Both the type of hardware and the type of software used in a particular configuration impact everything from where you can use the system to the type of documents you can create. For example, if you have a large desktop computer that you use for word processing or spreadsheet applications, you cannot take it with you when you travel. If you have a smartphone, you can take it with you when you travel, but it may be difficult to edit a report or update a spreadsheet on the small screen, not to mention the effect running such applications might have on the device battery. You also want to consider the ability of the hardware and software to work together. Recall that product agnostic software and hardware are compatible with other programs and devices. When thinking about this great variety of computer configurations, it is helpful to look at them in two groups:.those used by organizations and those used by individuals Computers for Organizations Companies and other organizations use the full range of computers. Large organizations can afford the largest and most expensive machines, and such companies are more likely to need all the processing power that these huge machines have. Many companies also want some of their workers, such as salespeople, to have small.handheld computers Supercomputers The largest and most powerful computers can process huge amounts of data very quickly. These superfast scientific computers are called supercomputers. Where most CPUs can perform millions of calculations a second, supercomputers can perform millions upon millions of calculations a second. The organizations using supercomputers do very complex work, such as forecasting the weather or creating detailed models of nuclear reactions. TECHNOLOGY@SCHOOL When computers are linked in a network, the network is set up to prevent people who have no right to be in the network from having access to the.information. Typically, users use a password to gain access THINK ABOUT IT! Think about the kind of information stored on a school network. Which ?informational items listed below do you think should have blocked access class schedules students’ grades students’ health records sports team results scheduled school events Supercomputers are not only the largest and most powerful type of computer, they are also the most expensive. A single supercomputer can cost hundreds of thousands of dollars or tens of millions of dollars. They are also extremely rugged and dependable systems, so.users can place constant heavy workloads on them Mainframes The mainframe is another type of computer used by government agencies and large corporations. Mainframe computers are used in centralized computing systems as the storage location for all or most of the data. Other, less powerful computers connect to the mainframe so users can access the data. For example, airline company employees use mainframes to store and process reservations. In this way, reservations agents and travel agents all around the world can locate and use the same information at the same time. The trend now is to replace mainframes with servers. Even many government agencies have reduced the amount they rely on mainframes. Figure 2.3.1 Some organizations use very.large computer systems and house them in their own special environments SCANRAIL/123RF.COM Servers Most organizations connect their computers together in a network. All the computers that are part of the network are connected to a computer called a server. The server stores data and programs that people on the network can use on their personal computers. A computer connected to a network, called the host, uses a special program, called the client, to contact the server and get data from it. Unlike terminals, computers on a network can have their own disk storage, but the main source of data for the network is still the server. Servers can be host or client-based. If the server is host-based, the server runs the programs and receives directions from the client computers. In a client-based server the programs and processing are split between the client and host computers. The networking found in servers can also be found in peer-to-peer networks, where computers in a system share resources and there is no host computer. REAL-WORLD TECH THE INTELLIGENT ROOM VALERIE POTAPOVA/SHUTTERSTOCK Some businesses are using a powerful new approach to working together called the Intelligent Room. The room looks like a normal conference room, but computercontrolled microphones and cameras placed around the room make sure that the speaker is always in view. This is especially helpful for videoconferencing, in which a video of a meeting in one room is sent to another group of workers in another room. Screens mounted on the wall can be used to display data from computers simply by touching the screen. Why is the camera’s ?ability to follow the speaker useful for videoconferencing Computers for Individuals Most individuals do not need as much computing power as.organizations do. They can use smaller—even mobile—devices for their computing needs Workstations The most powerful and expensive personal computers are workstations. Architects, engineers, designers, and others who work with complex data use these machines for their power and speed. Career Corner COMPUTER ENGINEER Designing compact, powerful machines like subnotebooks and PDAs is the work of computer engineers. They design and test components and then put them together to make sure they work properly. Engineers need to know software and programming as well as understand the workings of hardware. Demand for computer engineers is expected to be good in the coming.years Personal Computers Most individuals use personal computers to do everyday jobs more quickly and easily. Desktop computers are personal computers that are small enough to fit on or under a desk but too large to move around easily. Desktop computers may be connected to a network or they may be standalone, which means they are not connected to any network. Small portable computers such as laptops and notebooks are as powerful as a desktop but can be easily carried around. They usually include an internal hard drive. They can connect to an AC power source or run on battery power. Laptops usually have a monitor, keyboard, and pointing device built-in, as well as ports and Wi-Fi for connecting to.peripherals and the internet. Some, called all-in-ones, have touchscreens, as well Tablet Computers Tablet computers are small, portable computers that have a flat panel display. The display is usually a touchscreen, which can be used with a finger or a stylus. There is no external keyboard. They may have ports and usually allow wireless connection to peripherals and a network. The primary characteristic of a tablet is its small size. Most are.about 6-inches wide by 8-inches tall and weigh less than 1 pound Smartphones A smartphone is a telephone with computing capabilities. Most smartphones are mobile, or cellular. Smartphones provide internet access using 3G, 4G, 5G, or Wi-Fi technology. They run apps, which are small programs designed for one purpose, such as checking the weather, finding a nearby restaurant, or playing a game. Smartphones have built-in devices such as cameras, microphones, and speakers. They have internal storage for saving data such as pictures, music, contact information, and a calendar. Smartphones also have the capability to send and receive emails and text messages. Some smartphones.have attached keyboards, but most use a pop-up keyboard on the touch-screen display Evolving and Emerging Technologies Technology is always changing and adapting. As new needs are identified, technology is developed to meet those needs. As a technology becomes widely used, it may be modified to be more efficient or to meet a new or different need. A new, innovative technological development is called an emerging technology. Augmented reality, in which digital information is layered over someone’s real-world view, is an emerging technology. An existing technology that changes to be more efficient or meet a different need is called an evolving technology. For example, using a smartphone to pay for products is one way existing technologies are evolving. IC3 ✓Describe concepts related to.computing devices Figure 2.3.2 Using a smartphone to pay in a retail store is an example of evolving technology. LESSON 2-4 Mobile Devices OBJECTIVES Recognize the requirements of cellular connections. Distinguish the capabilities and limitations of cellular phones, smartphones, and cellular tablets. Describe the purpose of a SIM card. Explain how mobile devices connect to networks. Identify the benefits and.limitations of Wi-Fi and cellular connections. Identify elements of a cellular service contract AS YOU READ SEQUENCE INFORMATION Use a column chart to help you compare and.contrast types of mobile devices as you read TERMINOLOGY 3G 4G 5G bandwidth limit cable modem cell site cells cellular network system cellular phone cellular service contract cellular service provider ebook ebook reader full-duplex hard-wired telephone mobile device mobile internet services Mobile Telephone Switching Office (MTSO) personal digital assistant (PDA) Public Switched Telephone Network (PSTN) subscriber identification module (SIM) card touchscreen wearable computer Wi-Fi wireless data plan Mobile Devices A mobile device is a wireless computer that is small enough to use when it is held in your hand. While all portable computers are mobile, including laptops and notebooks,.the term generally refers specifically to smartphones and tablets Features of Mobile Devices Mobile devices run on battery power, and the battery must be kept charged. They have operating systems designed specifically for mobile devices, such as Google’s Android or Apple’s iOS. Most mobile devices have a touchscreen interface that can be used with a hand or a stylus. They are primarily used for communication via email or messaging and for accessing the internet, but most can do many of the same things a.personal computer can do Types of Mobile Devices The two main types of mobile devices are cell phones and tablets. Ebook readers, such as Amazon’s Kindle, are also considered mobile devices, as are personal digital assistants (PDAs). A smartwatch is a mobile device, or a wearable computer. Wearable computers are designed to be worn on the body, leaving the hands free for other tasks. They are usually intended for a specific purpose, such as inventory control or for monitoring body systems, such as heart rate. They may be worn on the arm or wrist or around the waist like a belt. Smartwatches are worn on the wrist and tell the time along with having the ability to run apps. Some wearable computers are worn as eyewear and can.affect vision or display information Cell Phone vs. Smartphone All smartphones are cell phones, but not all cell phones are smartphones. A cell phone is any mobile cellular device that can be used to make a phone call. Some cell phones can be used for sending and receiving text (SMS) messages as well. Most have built-in features such as a contact list for storing telephone numbers and a calendar. However, you cannot add programs or customize the built-in programs. TECHNOLOGY@WORK Communicating with cell phones can pose a major security risk. Wireless communication can be monitored by outsiders, who can intercept and overhear what is being said. Some employers prohibit the use of most wireless devices for company.communication THINK ABOUT IT! How might eavesdroppers use information collected from wireless communications to harm a company? Can you think of other risks posed by using cell ?phones Cell Phone A cell phone actually is a type of radio. In fact, that’s the definition: cellular phones are mobile phones that use radio waves to communicate. A cell phone is a full-duplex device. That means that you use one frequency for talking and a second, separate frequency for listening. Both people on the call can talk at once. Early cellular phones were called radiotelephones and were used in ships at sea and in police cars. Radiotelephones were very useful during World War II, when they were used to send military information. For a while after that war, only a few people in a city could use radiotelephones at one time. New technology, however, soon increased the number of possible callers by.adding more radio frequencies within each city Smartphone A smartphone is a cellular device that can do much more than make phone calls. Smartphones are, in effect, mobile computers. They have operating systems such as iOS or Android that make it possible to download and run mobile applications, or apps. You can use them to do many of the same tasks you do on a desktop, laptop, or tablet, including sending and receiving email, sending and receiving multimedia messages (MMS), managing a schedule, storing notes, using a word processing or spreadsheet program, uploading.videos or pictures to social networking sites, streaming music and video, and playing games What Does “Cellular” Mean? When you use a traditional analog landline phone, the call is connected through a wire. The wire from your house is connected to a telephone pole or buried cable in the local loop and from a local office to long-distance wires. Digital landline phones connect to a cable or fiber optic system through a router. Cell phones bypass part of.the wired system, using a cellular network system instead Locating Cells Cell phone network systems are divided into cells, or geographic areas to which a signal can be transmitted. Each cell has a cell site, also called a base station, for all the cellular phones in that area. Each cell site has a radio tower that receives radio signals from other towers and sends them on to still other towers. As a caller moves from one area to another, a new cell site automatically picks up the call to keep the signal strong and clea

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