Chapter-3-Computer-Hardware-and-Peripherals_letcture.pdf

3 Chapter Computer Hardware and Peripherals Your Digital Toolbox What You’ll Accomplish When you nish this chap...

3 Chapter Computer Hardware and Peripherals Your Digital Toolbox What You’ll Accomplish When you nish this chapter, you’ll be able to: 3.1 Identify the major types of digital devices. 3.2 Recognize the components that make up a digital device and give an example of each part of a digital device. 3.3 Identify and differentiate between input and output devices that are used with today’s digital devices. 3.4 List the components to assess and factors to consider when purchasing a digital device. Why Does It Matter We live in a time when digital devices rule. Whether you always have to have the latest gadget or are hesitant to adopt new technology, you still must real- ize that these devices, from the tablet you use to browse the web and email to the Xbox One you use to play games and stream videos, are an important part of your life. Understanding the parts of the hardware that make up these devices, how you get information in and out of them, and how to make wise choices when purchasing new technology can help you cope and prosper in our digital age. The online course includes additional training and assessment resources. 59 The tangible part of computing starts with hard- ware. Components for input, processing, Course Content output, and storage allow you to put data in and Take a Survey get useful information out. Technology in Your Future Video 3.1 A World of Digital Devices As you read in Chapter 1, digital devices differ from analog devices in that they use symbolic representations of data in the form of code and can process words, num- bers, images, and sounds. Today the number of devices that t that de nition has expanded far beyond your desktop computer, but these devices still have certain things in common. They all have some form of memory and, however basic, an operating system; they provide a way to input and store data and output information; and they have a source of power. Some digital devices have input and/or output features built in, such as with a laptop computer or smartphone. Others use peripheral devices that physically or wirelessly connect with them. For example, your desktop computer keyboard is a peripheral device used to input data, and your printer is a peripheral device used to produce output. Digital devices come in many forms and sizes. 60 Our Digital World  3.2 The Parts That Make Up Your Computer Compare a typical desktop and laptop computer and you’ll nd that, although they may be packaged differently, they each contain similar hardware that processes data, provides battery power, offers ports and wireless connections for connecting to peripheral devices and networks, and stores data. The Motherboard If you were to open up your computer, you’d see that the motherboard is the pri- mary circuit board (a board containing electronic connections). It holds the central processing unit, basic input/output system, memory, and other components (see Figure 3.1). The motherboard is really just a container where the various working pieces of your computer slot into one compact package. Circuits on the motherboard connect the components contained on it. The central processing unit (CPU), which is a microprocessor (also called by the shorter terms processor or core), sits on the motherboard. The CPU processes a user’s requests, such as opening documents or formatting text. A CPU is a thin wafer or chip made up of a semiconducting material, such as silicon. It contains an integrated circuit made up of a combination of miniaturized components and drives the system’s computing capabilities. (Note that the term central processing unit is sometimes, albeit incorrectly, used to refer to the case that contains the processor and everything else within this case.) A multicore processor contains more than one processing unit or core. By split- ting up the work of computing tasks, multiple cores make your computer work faster. Multicore processors include dual core, which contains two processors, and quad core, FIGURE 3.1 The Operations of the Motherboard The motherboard is a container for various processors and expansion slots for cards that add functionality such as sound, graphics, and memory. memory module CPU slots (RAM) slots expansion slots Chapter 3 Computer Hardware and Peripherals 61 which contains four processors. Computer chip manufacturers are starting to come out with six-core and eight-core processors. These cores may be integrated onto a single chip or be located on separate chips, in which case they may be referred to as multi-chip processors. How many cores you can t on a chip essentially depends on how small the cores are. For example, quad cores were originally built on two chips, but as cores got smaller, those four cores were able to t on a single chip. All cores interact with the integrated memory controller on your computer, pull- ing data from memory to help them process tasks, and storing results of tasks back in memory. Cores may also have their own cache—a small high-speed memory storage area that holds the data that’s most likely to be needed next—reducing the time it takes to access memory. (Cache memory was discussed in Chapter 1.) Electronic connections between the processors and computer memory allow them all to interact. In the near future, processors may be able to connect using light, which will make your computer even faster. Multicore processors are most ef cient when used with software designed to take advantage of the processor’s multitasking capabilities. Designing software in a way that allows tasks to be parallelized (run pieces on two or more processors at once) is important for better performance. In addition to the processors, the motherboard also holds different types of memory. Read-only memory (ROM) is the permanent memory, or nonvolatile memory. ROM is hardwired into a chip. In a PC, the read-only memory stores the BIOS (basic input/output system). During the boot-up sequence, the BIOS checks devices such as your memory, monitor, keyboard, and disc drives to ensure they are working properly and then starts them up. It also directs the hard drive to boot up and load the operating system (OS) to memory. Random access memory (RAM) chips are slotted into the motherboard and are used to store programs and data while the com- “ puter is in use. This memory is temporary, or volatile. Each memory location in RAM can be Researchers at IBM have created accessed in any order, which speeds up process- computer chips that behave more like actual brains when processing ing. (This differs from storage devices such as information. Systems built with USB sticks or DVDs that store and retrieve data these chips will be called ‘cognitive one le at a time.) computers.’… Cognitive computers are While some computers have built-in sound or expected to learn through experiences, graphics cards, others include them as expansion nd correlations, create hypotheses and ” cards. These cards enable input and output of remember. sound or images. Your laptop computer can also —Rob Spiegel, TechNewsWorld accommodate PC cards that slot into a built-in card reader to provide other kinds of functionality such as additional USB ports or wireless networking capabilities. Power Supply All computing devices require power to work, whether that power is accessed by plugging a cord into a wall outlet, operating off a charged battery, or using power from solar cells. A power supply in a desktop or laptop computer is located where the power cord is inserted into the system unit. This metal box contains the connection for the power cord and a cooling fan to keep the connection from overheating. The power supply switches alternating current (AC) provided from your wall outlet to lower voltages 62 Our Digital World in the form of direct current (DC). A laptop computer also contains a battery that is charged when you plug the power cord into your wall outlet. Your operating system is capable of sending a signal to the power supply to instruct it to sleep or hibernate. This action puts the computer into a lower power mode or no power mode without losing your unsaved work. To take some computers out of sleep or hibernation mode, you can simply move the mouse or press any key. For most sys- tems, however, you have to brie y press the power button. Tablets and smartphones use USB chargers that can be connected to the device and then plugged into a wall outlet or a computer using an adapter. You can also purchase USB charger hubs, which are devices you plug into an outlet and then use to insert multiple USB connectors so that you can charge multiple devices at once. Charging from an outlet is much faster than charging from a computer. A newer technology trend that is emerging is the charging mat. A charging mat or charging pad allows you to charge multiple devices simul- taneously without connecting them to the mat with a cable. Charging mats typically use the same level of power that it takes to charge a device from an outlet. Wireless charging works with devices such as iPhone X to transfer an Charging mats are a way to charge more than electromagnetic charge to a device from one device at the same time. a charging station. Ports A computer uses a port to connect with a peripheral device such as a monitor or printer or to connect to a network. A physical port connects a computer to another device, sending a signal via a cable (as with a USB port), infrared light (as with an infrared port), or a wireless transmitter (as with a wireless mouse or keyboard). Some types of physical ports (commonly called just ports) in use today are serial, USB, FireWire, Thunderbolt, and infrared, as shown in Figure 3.2. A serial port is a port, built into the computer, that is used to connect a peripheral device to the serial bus, typically by means of a plug with 9 pins. (A bus is essentially a subsystem of your computer that transfers data between the various components inside your computer.) Network routers in a business setting use serial ports for administra- tion, although they are being replaced by web-based administration interfaces. A universal serial bus (USB) port is a small rectangular slot that has become the most popular way to attach everything from wireless mouse and keyboard transmitters (the small devices that send wireless signals to devices) to USB ash drives for storing data. USB rst came out in version 1.0, which supported a 12 megabits per second (Mbps) data rate (the measurement of the speed at which data can be transmitted). USB 3.0 became available in 2010, providing a transfer rate of up to 5 Gbps; and USB 3.1, introduced a few years later, provided even faster transfer, called SuperSpeed, with a data rate of 10 Gbps. USB-C, introduced in 2014, provides a small, reversible plug connector. Chapter 3 Computer Hardware and Peripherals 63 FIGURE 3.2 Ports in Your Computer PC ports laptop ports USB ports parallel port PS/2 mouse port IrDA port serial port HDMI port PS/2 keyboard port VGA port game port Ethernet (RJ-45) port FireWire ports USB ports FireWire port Ethernet (RJ-45) port VGA port Thunderbolt port audio ports modem (RJ-11) port modem (RJ-11) port Usually a computer has two to four USB ports that you can use to attach periph- eral devices. Should you need to plug in more peripherals than your computer has USB ports, you can add a hub that increases the number of available USB ports. Plug the USB hub into one of your computer’s USB sockets and then plug USB devices into the ports on the hub. Most USB hubs offer four ports, but some offer more. A FireWire port is based on the same serial bus architecture as a USB port. FireWire provides a high-speed serial interface for peripheral devices such as digital cameras, camcorders, or external hard disk drives. Generally used for devices that require high performance, the newest version of FireWire, called FireWire 800, is capable of transferring data up to 800 Mbps. The Thunderbolt port, introduced on Apple’s MacBook Pro in 2011, was devel- oped by Intel and Apple to provide a peripheral connection standard that combines data, audio, video, and power within a single high-speed connection. The newest version of Thunderbolt, Thunderbolt 3, doubled bandwidth and cut power consump- tion in half. Thunderbolt’s high-speed connection supports high-resolution displays and other devices that require a lot of bandwidth, such as high-end video cameras or data storage devices, and is generally expected to replace FireWire. Originally added to Apple devices, Thunderbolt is now being added to some PCs, making the port no longer strictly an Apple favorite. An Infrared Data Association (IrDA) port allows you to transfer data from one device to another using infrared light waves. Today the ability to transmit wirelessly between devices using Bluetooth (a wireless communications standard) is making IrDA ports obsolete. You can add Bluetooth connectivity via a device that connects to the USB port. MIDI is a communications protocol that allows computers and devices such as musical synthesizers and sound cards to control each other. Game ports on older computers allowed the MIDI device to be connected to a computer. A new version of MIDI that uses a high-de nition protocol is being created. This HD MIDI protocol will accommodate more channels to carry data as well as create improved resolution of data values, allowing for clearer rendering of audio. 64 Our Digital World Wireless Connections Most new computing devices have a built-in wireless adapter with the ability to detect and connect wirelessly to the internet if there is a Wi-Fi hotspot within range. Computers also have a standard wired network connection—variously called a NIC (pronounced “nick”), an RJ-45, or an Ethernet connector. Wired connections are gen- erally faster than wireless connections. Bluetooth wireless capability may also be built-in on your computer. If not, plug-in adapters are readily available. The technology can also be found in computer peripher- als such as wireless mice, keyboards, and printers. Storage Because saving the work you’ve done on your computer is so important, computer man- ufacturers have devised several ways to store all kinds of data, from numbers and images to words and music. All storage media have methods for reading and writing data. The various storage media on a computer are accessed using drives, which are identi ed on a Windows-based computer by a unique letter. For example, your com- puter’s hard disk is typically identi ed as the C drive, while a DVD or USB drive might be labeled E, F, or G. Mac computers give each drive a name, such as Mac HD for the hard drive and DVD_VIDEO for a DVD drive into which you have inserted a video. If you are connected to a network, you may also be able to access shared net- work drives. Hard Disks The rst place most of us save a copy of our work is on our hard disk, which is the disk drive that is built in to the computer. When you save a le to your Documents folder in Windows 10, for example, it is saved to your hard disk. The platters or disks in the drive rotate and one or more so-called “heads” read and write data to them. Because all hard disks eventually fail, the wise person uses other media storage or cloud storage to make backup copies. Optical Drives Your desktop computer is likely to have a built-in drive where you can place a CD or DVD to read content stored there or store data of your own. This type of drive is called an optical drive. To save on weight and size, many laptops today have no CD/DVD drive. Manufacturers assume you will download most of your software or content or use an external CD/DVD drive when necessary. Another type of optical drive that is built into some computers is a Blu-ray disc drive, mostly used for high-de nition movies and games. Discs placed in optical drives are covered with tiny variations, or bumps, that can be read as data by a laser beam in the drive. Optical drives use these optoelectronic sensors to detect changes in light caused by the irregularities on the disc’s surface. If you buy a movie or game on a disc rather than accessing the content online, it is likely to be in the Blu-ray format. External Hard Drives If you’d like additional storage, you might consider buying an external hard drive. External hard drives typically connect to your computer via a USB, FireWire, Thunderbolt, or Serial ATA cable, but select high-capacity models can connect to a network via a wireless connection. Some call You can connect to some external these devices networked external hard drives, while others refer to hard drives with USB or Thunderbolt them as network attached storage (NAS). cables. Chapter 3 Computer Hardware and Peripherals 65  External hard drives are useful for backing up your entire computer system. Some portable external hard drives don’t even need a separate power source. Networked models can provide centralized storage for multiple teammates or family members or can serve as a “jukebox” for storing various forms of media such as music or videos. Flash Drives Whether you call them ash drives, USB sticks, or thumb drives, these small devices are a convenient way to store your data and take it with you. They come with capacities as big as 512 gigabytes (bigger than most hard drives just a few years ago), and some manufacturers have begun to release sticks whose capacity is mea- sured in terabytes. Flash drives use ash memory to record and erase stored data and to transfer data to and from your com- puter. Flash memory is also used in tablets, mobile phones, and digital cameras because it is much less expen- sive than other types of memory. Flash memory is nonvolatile, meaning that it retains information even in a Flash drives are small, portable storage devices that are gaining larger capacities all the time. powered-off state. Wireless Mobile Storage Devices Similar to a ash drive, a wireless mobile storage device allows you to store as much as 2 terabytes of data, wirelessly stream movies and music, and share content with your computer or other devices. This technology allows multiple devices to connect at the same time and can work over its own Wi-Fi network so no internet connection is required. Solid-State Drives (SSDs) A solid-state drive (SSD) is essentially a ash- based replacement for an internal hard disk. These drives are lighter and more durable than traditional hard disks and have paved the way for smaller, more portable com- puters with longer battery. In 2007, SSDs began to show up in commercially available computers. One of the rst was the XO Laptop (part of the One Laptop Per Child initiative in developing countries), and internal SSDs were also included in the new Apple MacBook Air and MacBook Pro released that year. Dell also began shipping an ultra-portable laptop with an SSD in 2007, and many other PC manufacturers have since followed suit, though the cost of SSDs has to come down before they will appear in most PC models. Intel’s superfast Optane SSD includes a memory chip that could potentially be used for high-capacity storage. Optane SSDs have been measured as being 10 times faster than conventional SSDs. Cloud Storage In addition to using physical storage, many users increasingly rely on cloud storage. Cloud storage refers to the storage of data on a web-connected server operated by a third party. You can access your les stored in the cloud from any location, using any computer with an internet connection. Cloud storage may be used for backing up information as well as sharing les with others. If you’ve ever lost or damaged your ash drive, you can appreciate how valuable it would be to have backup copies of your information that you could access via the web from your school, on a 66 Our Digital World trip, or in your of ce. Depending on your needs, you can choose either a fee-based cloud storage service or free services such as Microsoft OneDrive. Some of the most popular cloud storage services today are Dropbox, Google Drive, Amazon S3, Box, Carbonite, iCloud, and iStorage. Course Content Take the Next Step Activities 3.3 Input and Output Devices Your computer is capable of processing and storing data, but if you can’t get data into your computer and information out of it, this capability isn’t of much use. That’s where input and output devices come in. Examples of input devices are your keyboard to enter text or a microphone to record sound. Output devices produce information in one of several forms: printed What goes into your text on a page, sound from a computer in the form of digital speaker, or an image on your les may come out as printed text, monitor, for example. a movie, an image, or sound. A Wide Assortment of Input Devices A computer keyboard contains keys that you press to activate electronic switches. These switches in turn tell the active software on your computer or in the cloud to insert numbers, letters, or characters in a document or form. Today’s computer key- boards also allow you to combine some keystrokes to accommodate additional com- mands (the familiar Ctrl, Shift, or Alt combinations and function keys, for example). Some keyboards also include shortcut keys that allow you to manage media functions such as video or audio playback. Many users today also input data via onscreen key- boards, which require the user to switch among two or more keyboards to input let- ters, numbers, and symbols. Key presses are interpreted by the software program that controls the keyboard, called a device driver. The operating system then provides the key press information to the currently active program, such as a word processor or an email client. Keyboards can plug into your computer, be built into a laptop, or use a wireless connection. The option to use wireless input devices permits greater exibility in positioning your keyboard and mouse. Chapter 3 Computer Hardware and Peripherals 67  Your mouse, also referred to as a pointing device, detects motion in relation to the surface you rest it on and provides an onscreen pointer representing that motion. You might think of a mouse as being like the lever that a crane operator moves to control the crane, which moves up or down in the air according to the movements of the lever. A mouse prototype was invented in 1964 at Stanford University. The rst mouse was sold with the rst Apple Macintosh in 1984. A mouse can plug into your computer, be built into a laptop, or use a wireless con- nection. However it is connected to your computer, a mouse can function in several different ways. It can use: a mechanical device, such as a ball that rolls on a surface, to track motion. a light-emitting diode or infrared (IR) technology to sense motion, as with optical mice. an optoelectronic sensor that actually takes pictures of the surface. ultrasound technology to detect movement, as with 3-D mice. Two other input devices are commonly used with today’s digital devices: the touchscreen and the touchpad. A touchscreen is a visual display that permits the user to interact with a digital device by touching various areas on the screen, with either a nger or a stylus. A digital pen, such as the one that comes with Microsoft’s Surface 4, is used to write or draw on a touchscreen. The touchscreen has evolved with the development of portable devices and smartphones. Touchscreens are used in many different areas, from ATMs to airline kiosks. A touchpad, which senses nger movement, may be built into many computing devices. Both the touchscreen and the touchpad use the motion and position of a person’s nger to locate a position on the computer screen, either directly (touchscreen) or indirectly (touchpad). New input controls and interfaces are always appearing. For example, the Touch Bar on a MacBook provides controls for some input methods such as voice and formatting in a single bar at the top of the keyboard. The touch input panel on the Lenovo Yoga can be used as a virtual keyboard to draw or take notes with a stylus. The scanner has a very descriptive name, as its function is to optically scan hard copy of text or images to convert them into electronic les. Scanners may sit on your desktop (called atbed models), be built into an all-in-one printer, or be handheld. In the world of industrial design, 3-D scanners can scan all sides of objects and produce three-dimensional models of them. A webcam is a video camera that can be built into your computer monitor or purchased separately and mounted onto your computer. Both webcams and digital cameras can become input devices when they Webcams are often used with online interface with your computer to calling or meeting services so both upload photos or videos in digital le callers can see each other as they chat. formats. 68 Our Digital World  Gaming devices such as Xbox One and Wii U provide controllers you can use to input moves in a game. The controllers often combine multiple buttons, a joystick, and even motion sensors. Virtual reality systems that are used to simulate situations for learn- ing, such as for astronauts, offer wired data gloves that allow users to communicate with the system. A microphone is an input device for get- ting sounds, from narrations to music, into your computer in the form of audio les. Microphones might be built into your com- puter, be plugged in via a cable, or be part of a headphone set. Speech recognition software turns a user’s Virtual reality controllers allow a user to interact with a spoken words into text. Leading voice rec- game environment. ognition programs include Dragon Naturally Speaking and Dragon Dictate for Mac. The user typically completes a setup process to train the voice recognition software to understand his or her voice. The software then adjusts to the user’s speech patterns, enabling that person to give commands and create documents such as spreadsheets and emails. A mobile internet device (MID) also uses a variety of input devices. MIDs may offer virtual keyboards, foldable keyboards, touchscreens, voice recognition, or sty- luses for providing input. There has been a great deal of debate regarding mobile devices being used in automobiles. Today, automobile and mobile device manufac- turers are working to improve devices and software for hands-free use while driving. There are currently voice devices that enable a user to nd local businesses and open, create, and respond to email and SMS messages totally hands-free. Today, wearable devices are becoming more popular. Computers incorporated into watches, glasses, and clothing are always on. A user’s skin, hands, speech, or even eye movement can be used to provide input. WPAN (wireless personal area network) and WBAN (wireless body area network) protocols are being developed so you can make your body’s environment a moveable Wi-Fi network. Assistive technology includes a variety of devices and methods that enable physically challenged computer users to control their computer and provide input. For example, sip-and-puff or wand and stick devices enable users to give computer input using their mouths. Other assistive devices include Braille embossers, screen readers, and speech synthesizers. The Tongue Drive System is an example of assistive technology. Chapter 3 Computer Hardware and Peripherals 69  Computers in Your Career If you are interested in a career in healthcare, you need to know about how computers are being used to enhance the delivery of care. By using the internet, healthcare providers and patients can connect through two-way video calls, email, smartphones, and other forms of technology and computer devices. Telemedicine is extending care to patients in remote areas, emergency situations, and workplaces. Technology is also enabling the use of live interactive video and the ability to remotely collect and send diagnostic data. Healthcare professionals can participate in online discussion groups regarding health issues and even observe remote surgical procedures. Sites such as MeMD and Healthcare Clinics at Walgreens can even provide online medical consultations and prescriptions for a fee. Retail and manufacturing employees often use bar code readers and RFID readers. Bar code readers optically scan a set of lines to identify a product. RFID readers scan an embedded tag that emits a radio frequency. Both are used to pro- “ Garbage in, garbage out. ” —George Fuechsel, IBM technician, advising that bad input results in bad output vide input to a computer system so software can track inventory and sales activity. Getting the Most from Your Computer with Output Devices Any device that displays, prints, or plays content stored in your com- puter is an output device, including your monitor, speakers, head- Playing It Safe phones, printer, and/or projector. Keystroke logging software is a kind of Monitors and Speakers You may not think of your malware that can be monitor as an output device, but because it delivers information delivered to your computer stored inside your computer in the form of images, it is. In the case in several ways, but of a mobile phone or gaming device, the screens are output devices. it is most commonly Monitor output is temporary; once you turn the computer off, there downloaded when you go is no record of what was displayed. to an untrustworthy site Monitors may also include a speaker to add audio output. or click on an attachment Laptop computers usually have an internal speaker, while desktop in an email. The software computers may use external speakers. Another way to get audio records your keystrokes from your computing device is by plugging in a headset or by using as you type and sends the a wireless Bluetooth headset or speaker. information to a remote Monitors come in a variety of display sizes, from a few inches location. In this way on your smartphone to 10-inch screens on ultra-portable laptops someone might obtain your to huge desktop screens that may be over 30 inches across. Display bank account password size is the measurement between two diagonally opposite corners. and account number, for The latest USB 3.1 cables are enabling lightning-fast transfer of data example. Antivirus and such as high-de nition 3-D video to your computer monitor or TV antispyware software can screen. 4K screens are providing more vivid images for TVs, cam- help you locate such a eras, and monitors with almost twice the resolution of FullHD dis- program on your system plays. High dynamic range (HDR) is making a similar difference and get rid of it. for photos. 70 Our Digital World  Modern computer monitors use one of these technologies: Thin lm transistor active matrix liquid crystal displays (TFT active matrix LCDs) are the most prevalent type of monitor today. They use a thin lm transistor (TFT) to display output from your computer. Light-emitting diode (LED) displays use light-emitting diodes. They con- serve power and provide a truer picture than LCD models. Some new display technologies beginning to appear on computer monitors and television sets include the following: Surface-conduction electron-emitter displays (SEDs) use nanoscopic elec- tron emitters (extremely tiny wires, smaller than human hairs) to send elec- trons that illuminate a thin screen. Organic light-emitting diodes (OLEDs) project light through a thin electrolu- minescent (blue/red/green-emitting) lm layer made of organic materials. 3-D or 3-D-ready technology uses a polarized lens to display images. Usually, the viewer must purchase special glasses and may have to install separate IR equipment for use with the computer in order to view the 3-D effect. This 3-D technology is being used for both computer monitors and televisions. Bluetooth headsets let you talk on a mobile phone handsfree. Printers and Faxes A printer is the main way in which you can get hard copy (print on paper) output from your computer. The foundation for today’s printers was a dry printing process called electrophotography, also known as Xerox (hence the company of the same name). When the use of a laser beam was added, the business world saw the introduction of the laser printer in 1971 and inkjets (print- ers that spray jets of ink onto paper) in 1976. Hewlett-Packard threw its hat into the printer ring in 1984 with the rst laser LED displays are often used in television sets. Most printer for sale to the general public. computers can connect to a TV display to generate output. Chapter 3 Computer Hardware and Peripherals 71  A photo printer (which prints high-quality photos directly from a camera storage card) and a thermal printer (which heats coated paper to produce an image, like the kind you’ve seen printing receipts in retail stores) can also be used to create printed output. You may also encounter high-end commercial printers like the ones you see at your local copy store, and plotters, which are used to print large blueprints and other technical drawings. You can use fax programs to send content from your computer that comes out as printed copy at the receiving end. If you use a fax machine to scan content and then send it, the machine converts the scanned content into an electronic le and then sends it to the recipient’s fax machine, which prints it as a hard copy on the other end. In this case, the sending fax machine is an input device and the receiving fax machine is an output device. 3-D printing is a method of using printers to create 3-D objects from digital models. A 3-D printer prints layers on top of one another to build a precise, physical object, as opposed to traditional manufacturing, in which material is often removed to carve out an object. 3-D printing is being used to manufacture customized equip- ment, such as automotive parts, and patient-speci c devices, such as orthopedic implants. The 3-D printing industry is expected to total $13.2 billion globally and will experience an annual growth rate of 22.3% with revenues reaching $28.9 billion in 2020. Devices That Project Computer Content There are several dif- ferent devices that can be used to project computer content as part of a presentation, either in person or across the web. An LCD projector projects light through silicone panels colored red, green, and blue. The light passing through these panels displays an image on a surface such as a screen or wall. By blocking or allowing light to pass through pixels on the panels, these projectors can output a huge range of colors. If you give presentations, you will encounter LCD projectors. These output devices are popular for displaying PowerPoint slides and other types of content. 72 Our Digital World  Used with a projector, a document camera can be used to display text, slides, a 3-D object, or any other printed material on a screen. An interactive whiteboard (IWB) is a display device that receives input from a computer key- board, special pen, nger, tablet, or other device. The IWB may connect directly to a computer to show the computer desktop, or you might need a projector to show the desktop on the IWB. IWBs help improve communication in settings such as the classroom, the corporate world, sports coaching, and broadcasting. Information displayed on an IWB may be saved as a document and shared or printed later. Popular IWB brands include SMART Board, Promethean, mimio, eBeam, and PolyVision. Virtual Reality and Augmented Reality Displays A virtual reality system connects you to a computer-simulated world. Most An interactive provide visuals to the user and some provide sound whiteboard display device. as well. The user wears a head-mounted display and headphones if sound is being provided. In the more sophisticated systems, gloves with wiring allow the user to control actions with his or her hands. Virtual reality is a connection between user and computer that allows both input and output. This technology is used to train pilots, astronauts, doc- tors, and others by having them deal with simulated situations. Like virtual reality, augmented reality takes advantage of computer output. Augmented reality involves layering audio, video, and other output to improve our real world experiences. Virtual reality equipment like the Sony Morpheus headset for PlayStation is helping people in various industries to simulate and prepare for situations they might encounter in their work. Course Content Take the Next Step Activity Ethics and Technology Blog Chapter 3 Computer Hardware and Peripherals 73  3.4 Purchasing a Computer When faced with buying a new computer, many people get overwhelmed trying to gure out all the features and tech terms. The challenge is compounded because the speci cations for what makes up the latest and greatest computing device change frequently as manufacturers try to outdo each other. However, there are certain ques- tions you can answer to make an informed and intelligent computer purchase. What Are Your Computing Needs? Not everybody needs the newest, fastest, most high-powered computer, so don’t let sales hype sway you into buying more computer than you need. Activities that require higher levels of speed and performance include: Working with sophisticated graphics when performing tasks such as photo manipulation or web design. Working with audio and video. Uploading and downloading larger les over a network using a more recent Wi-Fi speci cation. Rich multimedia experiences such as gaming. Consider how much time you will spend on the computer. If you work at home and will use the computer eight hours a day, ve days a week, you need a better qual- ity (which often means more expensive) model. But if you only log on to read email a few days a week and manage your checkbook with a nancial program once a month, a lower-end model will probably do. Ef cient power consumption is also a consid- eration. Many systems comply with Energy Star requirements, but double-check the labeling and speci cations to make sure. Also consider how your choices create a larger impact on the world around you. Think about how the rapid change and constant upgrading of electronic devices has an impact on the environment. Technology doesn’t seem green when you think about all the computer monitors, cases, keyboards, hard drives, and printers that get disposed of each day. The green computing movement focuses on several important goals: Reduce hazardous materials. Make computing devices energy ef cient. Recycle outdated computing devices. Limit factory waste. Technology companies have been developing more energy-ef cient models with longer lasting batteries and promoting recycling efforts to reduce the impact of dis- carded equipment on the environment. Solid state drives that contain fewer moving parts and consume less power are also a growing trend. What Processor Speed Do You Need? As you learned earlier in this chapter, computers contain a processor that is located on a computer chip. Your computer processor speed in uences how fast your computer runs programs and completes various tasks. Clock speed relates to the speed at which a processor can execute computer instructions. Both clock speed and processor speed are measured in gigahertz (GHz). The more gigahertz, the faster the speed. Processor speed gets faster all the time. As of the writing of this textbook, 3 to 3.4 GHz was the higher end for the average computer, though the 3.6 GHz quad-core processor reaches the equivalent of 14.4 GHz with a single-core processor. 74 Our Digital World Those who want to play games and work with graphics require a more powerful computer system. Gordon Moore, one of the founders of Intel, is the creator of Moore’s Law, which states that over time the number of transistors that can be placed on a chip will increase exponentially, with a corresponding increase in processing speed and memory capacity. Since proposing this idea in 1970, Moore has largely been proved correct. How Much Memory and Storage Is Enough? Your computer has a certain amount of memory capacity that it uses to run programs and store data. When you buy a computer, you’ll notice speci cations for the amount of RAM and hard drive storage each model offers. As you read previously, RAM is the memory your computer uses to access and run programs. RAM chips come in different types, including DRAM, SRAM, and SDRAM. Most modern computer memory is some variation of SDRAM, including DDR-SDRAM, DDR2-SDRAM, DDR3-SDRAM, and DDR4- SDRAM. Performance has steadily improved with each successive generation. The more sophisticated programs you run and the more you want to run sev- eral programs at one time, the higher RAM you should look for. RAM chips are rated by access speed. This rating measures how quickly a request for data from your system is completed. Your computer will also use some RAM to run the operating system and application programs. RAM access speed is measured in megahertz (MHz). For example, 800 MHz is a typical access speed that would be suf cient to run most computers. Chip manufacturers continue to work to develop new, faster processors. Adding RAM to your computer is simple to do and one of the least expensive ways to improve the speed of your computer. The average computer hard drive’s capacity for data storage is measured in gigabytes (GB). A typical consumer PC might have anywhere from 500 GB to 750 GB of storage capacity, though terabyte systems measured in thou- Chapter 3 Computer Hardware and Peripherals 75  sands of gigabytes are becoming common. Large systems used by business and research institutes may have storage measured in petabytes (PB), or one quadrillion bytes. Likewise, data storage size is an issue for smartphones and tablets. Many smartphones and tablets feature up to 128 GB of storage. Which Operating System Is Right for You? Chapter 4 of this book goes into operating systems in detail, but when you go out shopping for a computer, there are a few reasons you should consider which operating system to use. All new computers come with an operating system installed, so the cost of the operat- ing system (OS) isn’t usually a factor. However, if you are buying OS software on its own (for example, to upgrade to a newer version), there are variations in cost to consider. Windows is a popular operating system, but if you are buying the software (as opposed to buying a computer with it already installed), it is costly. Also, because of its popularity, Windows computers are more often the target of viruses (though Macs are gaining in both popularity and virus problems). Linux is a Windows-like operating system that comes in different “ avors” such as Mint and Ubuntu. You can use the free, open source version of Linux or you can purchase a packaged edition. For a packaged edition, the company may charge a fee and add something extra, such as support and documentation. The Linux community offers lots of applications and add-ins to choose from. Mac computers are manufactured by Apple and use the macOS operating system. While Apple offers its own software written by Apple or third-party Apple developers, many software applications originally written for Windows are also available in Mac ver- sions, such as Microsoft Of ce. You can also set up your Mac to run the Windows oper- ating system alongside macOS, so you can take advantage of a wide variety of software. Operating systems are getting better at allowing users to interact with les created on other systems. 76 Our Digital World What Are You Willing to Spend? Computers range in price from a few hundred dollars to several thousand. Often, buying a base model and customizing it with additional memory and an upgraded monitor will get you the system you need. Laptops are still slightly more expensive than desktop models, but lightweight laptops such as ultrabooks have leveled the playing eld. It’s a good idea to use online sites to check out the best prices and read consumer reviews before buying. Where you shop can have an impact on price. You can shop for a computer in an online store, in a traditional retail store, or you can use online auctions or classi eds to nd deals on new or refurbished models. Retail stores provide the ability to try before you buy. You can spend time with the computer, getting the feel of the keyboard and viewing the display to see if it meets your needs. You can also direct any questions you have about the computer to a real, live salesperson. Manufacturer sites allow you to customize computers to your requirements. To help you answer your speci c ques- tions, many online sites provide shopping support using real-time chat, which can make buying online easy. Check to see whether memberships in organizations such as your university or member-discount retail stores such as Costco give you access to good deals. Also, think about shipping costs if you buy online, and note that retail stores often charge a restocking fee if you return a computer. Should You Opt for Higher-End Graphics and Sound? Those who work with a lot of visual elements (for example, photographers, gamers, or movie buffs) should opt for a better quality graphics card when purchasing a com- puter. Movies and games also use sound, so a high-end sound card is a plus too. Computers that have higher-end sound and image capabilities are referred to as gaming or multimedia models. In addition to more sophisticated sound and video cards, they usually have higher memory speci cations. Companies such as Dell and Lenovo offer buyers the opportunity to build a custom computer online. Course Content Take the Next Step Activity Chapter 3 Computer Hardware and Peripherals 77  Course Content Review and Assessment The online course includes additional training and assessment resources. Summing Up 3.1 A World of Digital Devices Some digital devices have multiple features built into one unit, such as a laptop com- puter or cell phone. Others use other peripheral devices that physically or wirelessly connect with them. 3.2 The Parts That Make Up Your Computer The motherboard is the primary circuit board on your computer and holds the cen- tral processing unit (CPU), BIOS, memory, and so on. The motherboard is a con- tainer where the various working pieces of your computer slot into one compact pack- age. Circuits on the motherboard connect the various components contained on it. The central processing unit, which is a microprocessor, sits on the motherboard. The CPU processes a user’s requests. A multicore processor contains more than one CPU, which in this situation is referred to as a core. Things that affect the processing speed of your computer include clock speed, cache, and the number of cores. The motherboard also holds different types of memory. Read-only memory (ROM) is the permanent, or nonvolatile, memory of a computer, hardwired into a chip. In a PC, the BIOS is stored in ROM. BIOS stands for basic input/output system, and this code is embedded in a memory chip also residing on the mother- board. During the boot-up sequence, the BIOS checks devices to ensure they are working properly and then starts them up. It also directs the hard drive to boot up and load the operating system (OS) to memory. Random access memory (RAM) chips store data and programs and allow access in any order, which speeds up processing. While some computers have built-in sound or graphics cards, others include them as expansion cards. A power supply in a desktop or laptop computer is located where the power cord is inserted at the back of the system unit. The power supply switches alternating current (AC) provided from your wall outlet to lower voltages in the form of direct current (DC). Wireless charging uses an electromagnetic eld to charge a device. A computer uses a port to connect with a peripheral device such as a monitor or printer or to connect to a network. A serial port is used to connect a peripheral device to the serial bus via a cable with a plug that typically contains nine pins. A universal serial bus (USB) port is a small rectangular slot that provides a popular way to attach peripherals and storage devices. You can add a hub to expand the number of available USB ports. A FireWire port is based on the same serial bus architecture as a USB port. FireWire provides a high-speed serial interface for peripheral devices that require high performance, such as digital cameras, camcorders, or external hard disk drives. A Thunderbolt port is a peripheral connection standard that supports high-resolution displays and other devices that require a lot of bandwidth, such as high-end video cameras or data storage devices. An Infrared Data Association (IrDA) port allows you to transfer data from one device to another using infrared light waves. 78 Our Digital World  Some technologies, such as Bluetooth, allow for wireless communications between your computer and other devices. All storage media have methods for reading the data from the media (input) and for writing the data to the media (output). The various storage media used on a com- puter are accessed using drives. Storage media include the hard disk built into your computer; an optical drive to read a CD, DVD, or Blu-ray disc; an external hard drive or a network attached storage (NAS) shared external hard disk; a ash drive; and a solid-state drive (SSD). Third-party cloud storage systems store and manage data on a web-connected server. 3.3 Input and Output Devices You use input devices to get data into your computer and output devices to get information out. In addition to a keyboard and a mouse, computer input devices include touchscreens, touchpads, scanners, digital cameras and webcams, gaming devices, and microphones. Specialty input devices include foldable keyboards for mobile internet devices (MIDs), assistive technology devices, and devices often used in retail or manufacturing settings, such as bar code readers and RFID readers. Output devices include any device that displays, prints, or plays content stored in your computer, including your monitor, speakers, Bluetooth headsets, printer, or an LCD projector. 4K and HDR provide the latest resolution quality for monitors. Some devices provide both input and output functionality, such as a fax machine. 3-D printing is a method of using printers to create 3-D objects from digital models. A 3-D printer prints layers on top of one another to build a physical object, and 3-D printing is increasing in popularity as the technology develops. 3.4 Purchasing a Computer When buying a computer, you should consider the following questions: What are your computing needs? What processor speed do you need? How much memory and storage is enough? Which operating system is right for you? What are you willing to spend? Should you opt for higher-end graphics and sound? Your computer has a certain amount of memory capacity that it uses to run pro- grams and store data. When you buy a computer you’ll notice speci cations for the amount of RAM and hard drive storage each model offers. RAM access speed is mea- sured in megahertz (MHz). The average computer’s hard drive capacity for data stor- age and the storage capacity for smartphones and tablets is measured in gigabytes (GB). All new computers come with an operating system installed, so consider whether you want Windows, Linux, or a macOS system. Computers range in price from a few hundred dollars to several thousand. Often, buying a base model and customizing it with additional memory and an upgraded monitor will get you the system you need. Laptops are still slightly more expensive than desktop models. Where you shop can have an impact on price. Those who work with a lot of visual elements (for example, photographers, gamers, or movie buffs) should opt for a better quality graphics card. Movies and games also use sound, so a high-end sound card is a plus. Chapter 3 Computer Hardware and Peripherals 79 Terms to Know 3.1 A World of Digital Devices peripheral device, 60 3.2 The Parts That Make Up Your Computer motherboard, 61 Thunderbolt port, 64 chip, 61 Infrared Data Association (IrDA) port, 64 multicore processor, 61 MIDI, 64 parallelized, 62 wireless adapter, 65 read-only memory (ROM), 62 drive, 65 nonvolatile memory, 62 hard disk, 65 BIOS, 62 CD, 65 expansion card, 62 DVD, 65 PC card, 62 optical drive, 65 power supply, 62 Blu-ray disc, 65 charging mat, 63 optoelectronic sensor, 65 wireless charging, 63 external hard drive, 65 port, 63 network attached storage (NAS), 65 physical port, 63 ash drive, 66 serial port, 63 ash memory, 66 universal serial bus (USB) port, 63 solid-state drive (SSD), 66 FireWire port, 64 3.3 Input and Output Devices input device, 67 Bluetooth headset, 70 output device, 67 4K, 70 keyboard, 67 high dynamic range (HDR), 70 mouse, 68 thin lm transistor active matrix liquid infrared (IR) technology, 68 crystal display (TFT active matrix touchscreen, 68 LCD), 71 stylus, 68 light-emitting diode (LED) display, 71 digital pen, 68 surface-conduction electron-emitter touchpad, 68 display (SED), 71 scanner, 68 organic light-emitting diode (OLED), 71 webcam, 68 printer, 72 gaming device, 69 photo printer, 72 wired data glove, 69 thermal printer, 72 microphone, 69 plotter, 72 mobile internet device (MID), 69 fax machine, 72 assistive technology, 69 3-D printing, 72 bar code reader, 70 LCD projector, 72 RFID reader, 70 document camera, 73 keystroke logging software, 70 interactive whiteboard (IWB), 73 monitor, 70 virtual reality system, 73 speaker, 70 augmented reality, 73 80 Our Digital World