chapter 5 - Metropolitan State University of Denver
Contents
1. Learning Objectives After you have read this chapter you should be able to Differentiate between the four basic types of system units Describe system boards including sockets slots and bus lines Recognize different microprocessors including microprocessor chips and specialty processors Compare different types of computer memory including RAM ROM and flash memory Explain expansion slots and cards Describe bus lines bus widths and expansion buses Describe ports including standard and specialized ports Identify power supplies for desktop laptop tablet and mobile devices eofe N O GAON Explain how a computer can represent numbers and encode characters electronically Why should read this chapter System units are getting smaller faster cheaper and more power ful These staggering improvements are resulting in microchips inte grating with all aspects of our lives For example in the future we will see everything from microchips embedded in the brain that improve mental capacity to sensors that can literally read your mind This chapter covers the things you need to know to be prepared S for this ever changing digital world including e Types of microcomputers learn the strengths and weaknesses of desktops laptops tablets and mobile devices e Computer components understand the impact microproces sors and memory have on the power of a computer E o Peripherals and upgrades expan2. Computer technicians repair and install computer components and systems Certification in computer repair or associate degree from professional schools is required Salary range is 31 000 to 46 000 KEY TERMS AC adapter 126 all in one 114 analog 127 arithmetic logic unit ALU 118 arithmetic operation 118 ASCII 127 binary system 127 BIOS basic input output system 121 bit 127 bus 122 bus line 118 122 bus width 122 byte 127 cable 124 cache memory 120 central processing unit CPU 118 character encoding standards 127 chip 117 chip carriers 117 clock speed 119 computer technician 128 control unit 118 coprocessor 119 desktop 114 digital 127 DIMM 120 DVI Digital Video Interface port 123 EBCDIC 127 Ethernet port 123 expansion bus 123 expansion card 121 expansion slot 121 ExpressCard 122 external Serial Advanced Technology Attachment eSATA 124 FireWire bus 123 FireWire port 123 flash memory 121 GPU 119 graphics card 121 graphics coprocessor 119 handheld computer 116 hexadecimal system hex 127 High Definition Multimedia Interface HDMI 124 integrated circuit 117 laptop 114 logical operation 118 mainboard 117 memory 120 microprocessor 118 Mini DisplayPort MiniDP mDP 124 mini notebook 115 minitablets 115 mobile device 116 motherboard 117 multicore processor 119 musi
3. To learn more about other careers in information technology visit us at www mhhe com ce2015 and select Student Edition and then Careers 128 CHAPTER5 Chips inside Your Brain Have you ever thought it would be possible to be able to com municate with a computer by merely thinking Researchers are working with various devices usually worn on the head that can use your basic thoughts to move objects such as wheel chairs However the future will lie in implanted microchips that can communicate directly with our nerve cells Although their initial purpose will be to treat a variety of medical conditions they could eventually and con troversially be used to improve various brain functions of other wise healthy individuals For over a decade doc tors have been able to use deep brain stimulation DBS to treat several disorders such as Parkinson s disease As successful as it has been for many patients those implants simply send preset electrical impulses to the brain They do not involve an active commu nication between nerve cells and machines Researchers working on a chip known as ReNaChip hope to change this by using a programmable computer chip that is respon sive to what is going on in the patient s brain This silicon chip can measure the brain s elec trical activity and then deliver the appropriate stimulation when and where it is needed Another brain implant that is currently being deve
4. ing and sending audio and video smartphones run apps connect to the Internet and more Their system unit is located behind the display screen Components Personal computers come in a variety of different sizes shapes and capabilities While they look different and each has its own unique features they share surpris ingly similar components including system boards microprocessors and mem ory See Figure 5 5 a ugun BABE poua Fey EEE LEE PERETTI Ber rr erik s rrr eb ick ee mat fe ee fe pe pes pe TELELEVIViTr hl anata he A CAUTION Dangor of i ar i r s reassemble Do not dis Tablet Smartphone System unit components 116 CHAPTER5 Bus lines Socket Figure 5 6 System board ka What is the system unit ka What are tower units What is an all in one What is an ultrabook What is a mini tablet Describe and compare the four most common types of personal computers System Board The system board is also known as the mainboard or motherboard The system board controls communications for the entire computer system All devices and components connect to the system board including external devices like key boards and monitors and internal components like hard disk drives and micro processors The system board acts as a data path and traffic monitor allowing the various components to communicate efficiently with one another On a desktop computer the system board is
5. mation for games and simulations e Sound cards accept audio input from a microphone and convert it into a form that can be processed by the com puter Also these cards convert internal electronic signals to audio signals so they can be heard from external speak ers or home theater systems e Network interface cards NIC also known as network adapter cards are used to connect a computer to a net work See Figure 5 16 The network allows connected computers to share data programs and hardware The network adapter card typically connects the system unit to a cable that connects to the network e Wireless network cards allow computers to be connected without cables As we will discuss in Chapter 9 wireless networks in the home are widely used to share a common Internet connection Each device on the network is equipped with a wireless network card that communicates with the other devices Plug and Play was originally a set of specific hardware and software stan dards developed by Intel Microsoft and others As hardware and software have evolved however Plug and Play has become a generic term that is associated with the ability to plug any device such as a printer or monitor into a computer and E7 o AAAA ENKA SAO O ONO ooe ED s Figure 5 14 Expansion cards fit into slots on the system board THE SYSTEM UNIT 121 Figure 5 16 Network interface card have it play or work immediately Some devices however are
6. not an existing system is powerful enough for today s new and exciting applications Sometime you may get the chance to watch when a technician opens up a personal computer You will see that it is basically a collection of elec tronic circuitry While there is no need to understand how all these com ponents work it is important to understand the principles Armed with this knowledge you will be able to confidently make sound purchasing and upgrading decisions To efficiently and effectively use computers you need to understand the functionality of the basic components in the system unit including the sys tem board microprocessor memory expansion slots and cards bus lines ports cables and power supply units system Unit The system unit also known as the system chassis is a container that houses most of the electronic components that make up a computer system At one time all system units were in a separate case Advances in the miniaturiza tion of electronic components however have led to smaller and smaller computers with system units that share containers with other parts of the computer system As we have previously discussed a personal computer is the most widely used type of computer It is the most affordable and designed to be operated directly by an end user The four most common types are desktop laptop tablet and mobile devices Each has a unique type of system unit Desktops This is the most powerful
7. the 1 can be repre sented by a negative charge and the 0 by no electric charge In order to represent numbers letters and special characters bits are combined into groups of eight called bytes Whenever you enter a number into a computer system that number must be converted into a binary number before it can be processed To learn more about binary systems and binary arithmetic visit our website at www mhhe com ce2015 and select Student Edition then Explore and then Binary Any number can be expressed as a binary number Binary num PKA Binary bers however are difficult for humans to work with because they 00 00000000 00 require so many digits Instead binary numbers are often represented 01 00000001 01 in a format more readable by humans The hexadecimal system or hex uses 16 digits 0 1 2 3 4 5 6 7 8 9 A B C D E F to represent ue EYO BUOY ue binary numbers Each hex digit represents four binary digits and two 03 00000011 03 hex digits are commonly used together to represent 1 byte 8 binary 04 00000100 04 digits See Figure 5 23 You may have already seen hex when select ing a color in a website design or drawing application or when enter fs CESR wa ing the password for access to a wireless network 06 00000110 06 Character Encoding ae eee OE As we ve seen computers must represent all numbers with the binary se PRESEA ee system internally What about text How can a computer provide rep 09 00001001 09 resentat
8. 5 18 Bus is a pathway for bits e What is the difference between a system and an expansion bus Ga Discuss three types of expansion buses Ports A port is a socket for external devices to connect to the system unit See Figure 5 19 Some ports connect directly to the system board while others con nect to cards that are inserted into slots on the system board Some ports are stan dard features of most computer systems and others are more specialized Standard Ports Most desktop and laptop computers come with a standard set of ports for con necting a monitor keyboard and other peripheral devices The most common ports include e VGA Video Graphics Adapter and DVI Digital Video Interface ports pro vide connections to analog and digital monitors respectively DVI has become the most commonly used standard but VGA ports are still provided on almost all systems for compatibility with older lower cost monitors e Universal serial bus USB ports can be used to connect several devices to the system unit and are widely used to connect keyboards mice printers storage devices and a variety of specialty devices One such device a USB TV tuner card allows users to view and record television programs To learn how you can use a TV tuner card see Making IT Work for You TV Tuners on page 1250 A single USB port can be used to connect many USB devices to the system unit e FireWire ports provide high speed connections to speciali
9. Ports Five specialty ports are eSATA external Serial Advanced Technology Attachment for high speed connections to large secondary storage devices HDMI High Definition Multimedia Interface for high definition digital audio and video MIDI for dig ital music Mini DisplayPort MiniDP mDP for large monitors and Thunderbolt for high speed connec tions to up to seven separate devices connected one to another Cables Cables are used to connect external devices to the system unit via ports 132 CHAPTER5 POWER SUPPLY Power supply units convert AC to DC and power desktops AC adapters power laptops and tablets and recharge batteries ELECTRONIC REPRESENTATION Human voices create analog continuous signals computers only recognize digital electronic signals Numeric Representation Data and instructions can be represented electroni cally with a two state or binary system of numbers 0 and 1 Each 0 or 1 is called a bit A byte consists of 8 bits Hexadecimal system hex uses 16 digits to rep resent binary numbers Character Encoding Character encoding standards assign unique sequences of bits to each character Three standards are e ASCII American Standard Code for Information Interchange Historically used for personal computers e EBCDIC Extended Binary Coded Decimal Interchange Code Historically used for mainframe computers e Unicode 16 bit code most widely used standard CAREERS IN IT
10. every few minutes you should save or store the material Cache pronounced cash memory improves processing by acting as a tem porary high speed holding area between the memory and the CPU The computer detects which information in RAM is most frequently used and then copies that information into the cache When needed the CPU can quickly access the infor mation from the cache Having enough RAM is important For example to use the standard version of Microsoft Office 2013 you need 2 GB or 2 billion bytes of RAM Some applica tions such as photo editing software may require even more Fortunately addi tional RAM can be added to a computer system by inserting an expansion module called a DIMM dual in line memory module into the system board The capac ity or amount of RAM is expressed in bytes There are three commonly used units Figure 5 11 RAM chips mounted on circuit board Uni of measurement to describe memory capacity See Figure 5 12 nit Capacity ns Other types of RAM include DRAM SDRAM DDR and direct RDRAM To Megabyte MB 1 million bytes learn more about these other types of RAM visit our website at www mhhe com Gigabyte GB 1 billion bytes ce2015 and select Student Edition then Explore and then RAM Even if your computer does not have enough RAM to hold a program it might be able to run the program using virtual memory Most of today s operating sys tems support virtual memory With virtual memor
11. more privacy facts visit ka Name and describe the two components of a microprocessor our website at www mhhe com ce2015 and select Student Edition and then Privacy everything from fuel efficiency to satellite entertainment and tracking systems ka Define word clock speed multicore chip and parallel processing e What are specialty processors Describe coprocessors THE SYSTEM UNIT 119 Chip Circuit board Memory Memory is a holding area for data instructions and information Like microprocessors memory is con tained on chips connected to the system board There are three well known types of memory chips random access memory RAM read only memory ROM and flash memory RAM Random access memory RAM chips hold the pro gram sequence of instructions and data that the CPU is presently processing See Figure 5 11 RAM is called temporary or volatile stor age because everything in most types of RAM is lost as soon as the computer is turned off It is also lost if there is a power failure or other disruption of the elec tric current going to the computer Secondary storage which we shall describe in Chapter 7 does not lose its contents It is permanent or nonvolatile storage such as the data stored on a hard disk For this reason as we mentioned earlier it is a good idea to frequently save your work in progress to a secondary storage device That is if you are working on a document or a spreadsheet
12. not Plug and Play and require that new device drivers be installed as discussed in Chapter 4 To meet the size constraints of laptop computers tablets and mobile devices small credit card sized expansion cards known as PC cards have been developed These cards plug into PCMCIA slots called PC card slots or most recently ExpressCard slots See Figure 5 17 aiir PENEL concept check assis check What are expansion slots and cards Name four expansion cards Discuss Plug and Play e What are PC cards PCMCIA slots and ExpressCard slots Figure 5 17 PC card Bus Lines As mentioned earlier a bus line also known simply as a bus connects the parts of the CPU to each other Buses also link the CPU to various other components on the system board See Figure 5 18 A bus is a pathway for bits representing data and instructions The number of bits that can travel simultaneously down a bus is known as the bus width A bus is similar to a multilane highway that moves bits rather than cars from one location to another The number of traffic lanes determines the bus width A highway bus line with more traffic lanes bus width can move traffic data and instructions more efficiently For example a 64 bit bus can move twice as much information at a time as a 32 bit bus Why should you even care about what a bus 122 CHAPTER5 line is Because as microprocessor chips have changed so have bus lines Bus desi
13. scenarios where the individual with the implants could have an unfair advan tage over those who don t have them However others disagree arguing that the inte gration of technology and biol ogy is to be expected and it is nothing more than the next step in human evolution If such a technology became widespread and affordable would you opt to receive a chip implant Would you make a distinction between using one for a medical condition and sim ply for improving your mental abilities Do you think the future of humanity lies in the merging of technology with human biology j FANE AA iad fF LG hl a i i 129 VISUAL SUMMARY SYSTEM UNIT The System Unit SYSTEM BOARD System unit system chassis contains electronic com ponents The most common personal computers are desktop laptop tablet and mobile device Desktop Desktop system units located in separate case tower unit tower computer has vertical system unit all in one computer combines system unit and monitor Laptop Laptop notebook system units contain secondary storage devices and input devices Ultrabooks ultra portables mini notebooks are lighter thinner and have longer battery life than other laptops Tablet Tablet system units are located behind the monitor They are smaller lighter and generally less powerful than laptops and use a virtual keyboard Mini tablets are smaller version of a traditional tablet Mobile De
14. typically located at the bottom of the system unit or along one side It is a large flat circuit board covered with a variety of different electronic components including sockets slots and bus lines See Figure 5 6 e Sockets provide a connection point for small specialized electronic parts called chips Chips consist of tiny circuit boards etched onto squares of sandlike material called silicon These circuit boards can be smaller than the tip of your finger See Figure 5 7 A chip is also called a silicon chip semiconductor or integrated circuit Chips typically are mounted onto chip carriers See Figure 5 8 These carriers plug either directly into sockets on the system board or onto cards that are then plugged into slots on the system board Sockets are used to connect the system board to a variety of different types of chips including microprocessor and memory chips Figure 5 7 Chip THE SYSTEM UNIT 117 environment Have you ever wondered what you should do with your old computers monitors and mobile devices The last thing you want to do is throw them away First consider donating them to various charitable organizations that work with local schools and low income families Otherwise recycle them Many computer retailers near you accept used devices and components for recycling even if they are broken Alternatively visit the website of your local government to find the electronics recycling center nearest
15. cal instrument digital interface MIDI 124 network adapter card 121 network interface card NIC 121 notebook 115 parallel processing 119 PC card 122 PC card slot 122 PCI Express PCIe 123 PCMCIA slot 122 personal computer 114 Plug and Play 121 port 123 power supply unit 126 processor 118 random access memory RAM 120 read only memory ROM 120 semiconductor 117 silicon chip 117 slot 118 smartphone 116 socket 117 soundcard 121 system board 117 system bus 123 system chassis 114 system unit 114 tablet 115 tablet computer 115 Thunderbolt 124 tower computer 114 tower unit 114 ultrabooks 115 ultraportables 115 Unicode 128 universal serial bus USB 123 universal serial bus USB port 123 VGA Video Graphics Adapter port 123 virtual memory 120 wireless network card 121 word 119 To test your knowledge of these key terms with animated flash cards visit our website at www mhhe com ce2015 select Student Edition and choose Chapter 5 and then Flashcards CHAPTER5 133 MULTIPLE CHOICE Circle the correct answer 1 This container houses most of the electrical components for a computer system a chip carrier c system unit b system board d Unicode 2 The most popular mobile device a all in one c smartphone b handheld d ultrabook 3 The mainboard or motherboard is also known as the a computer c mobile s
16. d specialized ports Give examples of each Describe power supply including power supply units and AC adapters PE es Discuss electronic data and instructions CHAPTER5 135 DISCUSSION Respond to each of the following questions Making IT Work for You TV TUNERS Did you know that you can record your favorite TV shows with a computer Review the Making IT Work for You TV Tuners on page 125 and then respond to the following a Do you currently have a DVR in your home If so who is the manu facturer If not have you considered pur chasing one Why or why not b How do the Windows Media Center DVR capabili ties compare with the DVR offered by your cable or satellite company Use a search engine to help you find these differences c Find at least two USB based TV tuners using any online store Note their prices and specifications What are their main differences Privacy CRYPTOPROCESSORS Did you know that some systems have speciality processors that automatically encrypt data before storing Review the Privacy box on page 119 and respond to the following a Who do you think would Symanise Encryption Seiutions need a cryptoprocessor Be specific b mie ae pee Do think these processors would be worth while for you to protect your privacy Why or why not c Are there any reasons why you might not want all your data encrypted Explain d Do you think that all computer e rip eeaeee systems shou
17. d your computer s abilities and speed Introduction L hi I m Liz and I m a computer technician I d like to talk with you about the different types of system units for personal computers I d also like to talk about various electronic components that make your computer work ethics Labor costs are much less in China than in the United States As a result many computers and peripherals sold last year were manufactured there While this has resulted in the loss of jobs elsewhere it has also improved the standard of living for millions of Chinese Unfortunately working conditions in Chinese factories have been widely reported to be well below acceptable standards Do you think consumers have an ethical responsibility regarding where and or how products are manufactured To see more ethical issues visit our website at www mhhe com ce2015 and select Student Edition and then Ethics 114 CHAPTER5 Why are some computers more powerful than others The answer lies in three words speed capacity and flexibility After reading this chapter you will be able to judge how fast powerful and versatile a particular personal computer is AS you might expect this knowledge is valuable if you are planning to buy a new personal computer system or to upgrade an exist ing system The Computer Buyer s Guide at the end of this book provides additional information This Knowledge will help you evaluate whether or
18. er of times the CPU can fetch and process data or instructions in a second Older microcomputers typically pro cess data and instructions in millionths of a second or microseconds Newer microcomputers are much faster and process data and instructions in bil lionths of a second or nanoseconds Supercomputers by contrast operate at speeds measured in picoseconds 1 000 times as fast as microcomputers See Figure 5 9 Logically the higher a microprocessor s clock speed the faster the microprocessor However some processors can handle multiple instruc tions per cycle or tick of the clock this means that clock speed comparisons Microsecond Millionth of a second can only be made between processors that work the same way Nanosecond Billionth of a second At one time personal computers were limited by microprocessors that could support a single CPU that controlled operations These computers were lim ited to processing one program at a time Now many personal computers have multicore processors that can provide two or more separate and independent CPUs For example a quad core processor could have one core computing a com plex Excel spreadsheet a second core creating a report using Word a third core locating a record using Access and a fourth core running a multimedia presenta tion all at the same time More significantly however is the potential for personal computers to run very large complex programs that previously required expe
19. gn or bus architecture is an important factor relating to the speed and power for a particular computer Additionally many devices such as expansion cards will work with only one type of bus Every computer system has two basic categories of buses One category called system buses connects the CPU to memory on the system board The other category called expansion buses connects the CPU to other compo nents on the system board including expansion slots A i 9 R D A a m A ia K D a a a kd eleeoeoeceeenes Weeeeeeees gt Expansion Buses Computer systems typically have a combination of different types of expan sion buses The principal types are USB FireWire and PCle e Universal serial bus USB is widely used today External USB devices are connected from one to another or to a common point or hub and then onto the USB bus The USB bus then connects to the PCI bus on the sys tem board The current USB standard is USB 3 0 e FireWire buses are similar to USB buses but more specialized They are used primarily to connect audio and video equipment to the system board b e PCI Express PCIe is widely used in many of today s most powerful computers Unlike most other buses that share a single bus line or path with several devices the PCle bus provides a single dedicated path for each connected device concept check oo What is a bus and what is bus width Figure
20. ions of the nonnumeric characters we use to communicate 10 00001010 OA such as the sentence you are reading now The answer is character 11 00001011 OB encoding schemes or standards Character encoding standards assign a unique sequence of bits 12 00001100 OC to each character Historically personal computers used the ASCII 13 00001101 OD American Standard Code for Information Interchange to represent characters while mainframe computers used EBCDIC Extended Ue SAY oe Binary Coded Decimal Interchange Code These schemes were 19 00001111 OF quite effective however they are limited ASCII for example only uses 7 bits to represent each character which means that only 128 total Figure 5 23 Numeric characters could be represented This was fine for most characters in representations THE SYSTEM UNIT 127 the English language but was not large enough to support other languages such as Chinese and Japanese These languages have too many characters to be repre sented by the 7 bit ASCII code The explosion of the Internet and subsequent globalization of computing have led to a new character encoding called Unicode which uses 16 bits The Unicode standard is the most widely used character encoding standard and is recognized by virtually every computer system The first 128 characters are assigned the same sequence of bits as ASCII to maintain compatibility with older ASCII formatted information However Unicode uses a variable number of bits
21. ld be required to have crypto processors Defend your position mupe piya biiir 1 conpiance Duspleel Etetpptian Badstisma log Caa a mE GOT Ben ee ard hier here pistera 136 CHAPTER5 Ethics JOB LOSS AND WORKING CONDITIONS Many computer related products are produced in China where working conditions are reported to be well below acceptable standards Review the Ethics box on page 114 and then respond to the following a What do you think about products produced in other countries like China What are the advantages and disadvantages to consumers Be specific 6 What are the ethical issues Be specific and defend your list of issues c Would you be willing to pay more for a MADE w tie USA co computer produced entirely in the United States More specifically would you be willing to pay three times as much for a smartphone Why or why not d Do you think consumers have an ethical respon sibility to know how goods are produced More specifically would your purchase decisions be affected by knowledge about the working conditions of those who make the product Why or why not BE AMERICAN BUY AMERICAN a Environment RECYCLING COMPUTER HARDWARE Have you ever wondered what you should do with your old computers monitors and mobile devices Review the Environment box on page 118 and then respond to the following a What do you typically do with your used or broken computers and mobile devices b What a
22. less network cards Plug and Play is the ability for a computer to recognize and configure a device without human interaction PC cards plug into PCMCIA slots and ExpressCard slots accept credit card sized expansion cards BUS LINES Bus lines also known as buses provide data pathways that connect various system components Bus width is the number of bits that can travel simultaneously System buses connect CPU and memory Expansion buses connect CPU and slots Expansion Buses Three principal expansion bus types are e USB universal serial bus can connect from one USB device to another or to a common point hub and then onto the system board e FireWire bus is similar to USB bus but more specialized e PCI Express PCIe bus is widely used provides a single dedicated path for each connected device THE SYSTEM UNIT 131 PORTS Ports are connecting sockets on the outside of the sys tem unit Standard Ports Four standard ports are e VGA Video Graphics Adapter and DVI Digital Video Interface provide connections to monitors e USB universal serial bus widely used to con nect keyboards mice printers and storage devices one port can connect several devices to system unit e FireWire provides high speed connections to FireWire devices such as camcorders and storage devices e Ethernet high speed networking port that has become a standard for many of today s computers Specialized
23. loped aims to help the blind regain some sight A microchip is implanted in the brain s visual cortex which is responsible for processing images This chip would communicate wirelessly with a camera located inside special eyeglasses worn by the individual The a 2552 fa w vi a 1 ely ed ro noe Gh ws se alee abn te i ba iW ris Aas i b I i L E gai oF AVi Y W 4 ape Hey images captured by that camera would be processed by the chip and then fed directly to the nerves in this area of the brain Getting close to the world of the unbelievable research ers are improving on the ability of computers to actually read human thoughts Currently one research team has been able to use a chip implant and computer to read the thoughts of a stroke victim in order to allow her to move a robotic hand Although the success rate is not 100 percent and the process ing is limited to basic movements the patient has already been able to get the robotic arm to hold a cup of coffee by think ing about it This research will hopefully lead to improved thought controlled prosthetic devices for millions of disabled individuals Many ethicists are con cerned by the potential use of such chips to improve human abilities instead of treating medical conditions For exam ple with tiny chips being able to store so much people could use brain implants to improve their memory This can lead to a variety of
24. mputer They are effectively a thin slab that is almost all monitor with the system unit located behind the monitor Tablets are smaller lighter and generally less powerful than laptop computers Like a laptop tablets have a flat screen but typically do not have a standard key board Instead most tablets use a virtual keyboard that appears on the screen and is touch sensitive Mini tablets are a type of tablet with a smaller screen While mini tablets oper ate like a traditional tablet they typically do not have all the functionality of the bigger tablets Their most significant advantage is that they are easier to transport in pockets and purses See Figure 5 4 O ee OF as a ty 6 Cae A PO Oe hat tee Pee ema Pal Re Ree GER PER ke hE ee by Pe meee 8 ee met he tee re ett eee pet ery fete en het fet ee peter 8 te tet ree ee ty eet eee cee ee ee ee oe et ee Figure 5 3 Ultrabook Figure 5 4 Mini tablet THE SYSTEM UNIT 115 Mobile Devices Mobile devices also known as handheld computers are the smallest and are designed to comfortably fit into the palm of one hand These systems contain an entire computer system including the electronic components secondary storage and input and output devices These devices are smaller and generally less pow erful than tablets By far the most popular mobile device is the smartphone It greatly extends the capabilities of a cell phone by providing computing power In addition to captur
25. n sive and specialized hardware E Series AMD For multicore processors to be used effectively computers must understand how to divide tasks into parts that can be distributed across each core an opera tion called parallel processing Operating systems such as Windows 8 and Mac OS X support parallel processing Software developers use this technology for a wide range of applications from scientific programs to sophisticated computer games Figure 5 10 Popular microprocessors See Figure 5 10 for a table of popular microprocessors Picosecond Trillionth of a second Figure 5 9 Processing speeds Processor EULA g A Series AMD Atom Intel i7 Intel Specialty Processors In addition to microprocessor chips a variety of more specialized processing chips nave been developed D rivacy Coprocessors are specialty chips designed to improve specific computing operations One of the most widely used is the graphics coprocessor also Did you know that one type of called a GPU graphics processing unit These processors are designed specialty processor is devoted to handle a variety of specialized tasks such as displaying 3 D images and exclusively to protecting your encrypting data privacy Called cryptoprocessors e Many cars have more than 70 separate specialty processors to control nearly these microchips perform encoding and decoding of data faster and more securely than a CPU These specialized chips concept check a To see
26. nformation the same way you and I can People fol low instructions and process data using letters numbers and special characters For example if we wanted someone to add the numbers 3 and 5 together and record the answer we might say please add 3 and 5 The system unit however is electronic circuitry and cannot directly process such a request Our voices create analog or continuous signals that vary to represent differ ent tones pitches and volume Computers however can recognize only digital electronic signals Before any processing can occur within the system unit a con version must occur from what we understand to what the system unit can elec tronically process Numeric Representation What is the most fundamental statement you can make about electricity It is sim ply this It can be either on or off Indeed there are many forms of technology that can make use of this two state on off yes no present absent arrangement For instance a light switch may be on or off or an electric circuit open or closed A specific location on a tape or disk may have a positive charge or a negative charge This is the reason then that a two state or binary system is used to represent data and instructions The decimal system that we are all familiar with has 10 digits 0 1 2 3 4 5 6 7 8 9 The binary system however consists of only two digits 0 and 1 Each 0 or 1 is called a bit short for binary digit In the system unit
27. ns in a second Multicore processors can provide multiple inde pendent CPUs Parallel processing requires programs that allow multiple processors to work together to run large complex programs Specialty Processors Specialty processors include graphics coprocessors also known as GPU or graphics processing unit pro cesses graphic images and processors in automo biles monitor fuel efficiency satellite entertainment and tracking systems MEMORY Memory holds data instructions and information There are three types of memory chips RAM RAM random access memory chips are called tem porary or volatile storage because their contents are lost if power is disrupted e Cache memoty is a high speed holding area for frequently used data and information e DIMM dual in line memory module is used to expand memory e Virtual memory divides large programs into parts that are read into RAM as needed ROM ROM read only memory chips are nonvolatile stor age and control essential system operations Flash Memory Flash memory does not lose its contents when power is removed EXPANSION SLOTS AND CARDS baddi bbkividdde oP ATTELS TTT TEETETTIIN BERRRREE CLR Most computers allow users to expand their systems by providing expansion slots on their system boards to accept expansion cards Examples of expansion cards include graphics cards sound cards network interface cards NIC net work adapter cards and wire
28. ntrol unit The control unit tells the rest of the computer system how to carry out a program s instructions It directs the movement of electronic sig nals between memory which temporarily holds data instructions and pro cessed information and the arithmetic logic unit It also directs these control signals between the CPU and input and output devices e Arithmetic logic unit The arithmetic logic unit usually called the ALU per forms two types of operations arithmetic and logical Arithmetic operations are the fundamental math operations addition subtraction multiplication and division Logical operations consist of comparisons such as whether one item is equal to less than lt or greater than gt the other Microprocessor Chips Chip processing capacities are often expressed in word sizes A word is the num ber of bits such as 16 32 or 64 that can be accessed at one time by the CPU The more bits in a word the more data a computer can process at one time Eight bits group together to form a byte A 32 bit word computer can access 4 bytes at a time A 64 bit word computer can access 8 bytes at a time Therefore the computer designed to process 64 bit words has greater processing capacity Other factors affect a computer s processing capability including how fast it can process data and instructions The processing speed of a microprocessor is typically represented by its clock speed which is related to the numb
29. om your cable outlet or over the air antenna to the back of the TV tuner If Windows does not automatically install the tuner consult the user manual for instructions 3 Start Windows Media Center With your TV tuner installed it will guide you through a setup process including a long scan for all available channels from your cable or antenna Using Windows Media Center This utility is included with Windows 7 and can be purchased as an upgrade for Windows 8 Although it contains many tools to manage your music photos and movies we focus on its DVR capabilities for TV and cable Q Once setup is complete click the TV option from the main menu Qe Click Guide and scroll up down and left right until you find a show you wish to record Right click the show and choose Record from the menu To play back a recorded show choose Recorded TV from the TV menu and click the show you wish to play back Once you have watched a recording choose the Delete option to free up space on your hard drive The number of hours you can record is limited by your available hard drive space If you have a high speed wireless network and several PCs in your home you will have the capability to watch your recorded shows via Media Center s streaming ability The web is continually changing and some of the specifics presented in this Making IT Work for You may have changed To learn about other ways to make information technology wo
30. ple s MacBook Pro computer provide high speed connections A single port can connect up to seven separate devices con nected one to another Thunderbolt ports promise to replace a number of different types of ports including Mini DisplayPorts Cables Cables are used to connect exterior devices to the system unit via the ports One end of the cable is attached to the device and the other end has a USB DVI FireWire Ethernet connector that is attached to a matching connector on the port See Figure 5 20 Figure 5 20 Cables 124 CHAPTERS5 Making iT work for you TV TUNERS Do you already use a DVR digital video recorder in order to record your favorite TV shows Although many cable and satellite companies offer this device did you know that Windows Media Center can perform the same function All you need is a device called a IV tuner that connects your antenna or cable to your computer Below are the steps to turn your Windows based com puter into a DVR Installing a TV Tuner A TV tuner is essentially a piece of hardware that allows your computer to process and display a cable or TV signal Although some usually pricey PCs may include this technology it is usually necessary to purchase it separately The easiest ones to install are those that connect externally to a USB port such as the AverTV Hybrid Volar Max Qe Plug the TV tuner into an available USB port on your computer Connect a coaxial cable directly fr
31. r purchasing a laptop provides the poet to drive all of cooler or fan the system unit components Proper storage If you are not going to use your laptop for a few weeks most e Laptops and tablets a AC manufacturers recommend that you remove the battery adapters that are typically located To see other tips visit our website at www mhhe com ce2015 and select Student Edition outside the system unit See and then Tips Figure 5 22 AC adapters plug into a standard wall outlet convert AC to DC provide power to drive the system unit components and can recharge the batteries These computers can be operated either using an AC adapter plugged into a wall outlet or using battery power Their batteries typically provide sufficient power for up to eight hours before they need to be recharged e Like laptops and tablets mobile devices use AC adapters located outside the system unit Unlike laptops and tablets however ultrabooks and mobile devices typically operate only using battery power The AC adapter is used to recharge the batteries concept check ka What are ports What do they do ka Describe four standard ports and five specialized ports ka What is a power supply unit What is an AC adapter Figure 5 21 Power supply unit Figure 5 22 AC adapter 126 CHAPTER5 Electronic Data and Instructions ee Have you ever wondered why it is said that we live in a digital world It s because computers cannot recognize i
32. re three alternatives to throwing these devices in the trash c Using a search engine find one nonprofit organization near you that will accept used computers List the name and URL d Visit the waste management or recycling page of your local government s website If it does not have a website contact it What is its rec ommended procedure for discarding your computers and other electronic devices CHAPTER5 137
33. rk for you visit our website at www mhhe com ce2015 and select Student Edition and then Making IT Work 125 Power Supply Computers require direct current DC to power their electronic com ponents and to represent data and instructions DC power can be pro Balance adapter and battery use he best practice is to use the laptop on battery vided indirectly by converting alter power for a little while without draining it completely 50 percent charge for example followed by charging it back to 100 percent Modern batteries should not be drained to 0 percent each day t S Does your laptop seem to be losing its charge sooner than it used to These batteries do lose power over time however you can take some steps to slow down the aging process nating current AC from standard wall outlets or directly from batteries Calibrate it Your laptop s manufacturer will recommend that you calibrate or reset your e Desktop computers havea power battery every few months Follow its guidelines on the web or in your instruction manual supply unit located within the as it will ensure that the battery meter in your operating system is accurate and that you system unit See Figure 5 21 This are getting the expected charge time unit plugs into a standard wall Avoid excessive heat High temperatures can accelerate the deterioration of modern outlet converts AC to DC and batteries Therefore avoid exposure to excessive heat and conside
34. t ____ 3 System board component that provides a connec tion point for specialized cards or circuit boards f random access E ___ 4 Provide connection points for chips ___ 5 Atype of memory that improves processing by h sockets acting as a temporary high speed holding area u between the memory and the CPU j USB __ 6 Atype of memory that provides a combination of features of RAM and ROM 7 A generic term that is associated with the ability to attach any device onto a computer and have it play or work immediately 8 This bus connects the CPU to memory on the system board 9 This port can be used to connect many USB devices to the system ___ 10 A socket for external devices to connect to the system unit For an interactive matching practice test visit our website at www mhhe com ce2015 select Student Edition and choose Chapter 5 and then Matching OPEN ENDED On a separate sheet of paper respond to each question or statement Describe the four most common types of personal computers Describe system boards including sockets chips chip carriers slots and bus lines Discuss microprocessor components chips and specialty processors Define computer memory including RAM ROM and flash memory Sa saree pe se Define expansion slots cards Plug and Play PC cards PCMCIA slots and ExpressCard slots Describe bus lines bus width system bus and expansion bus Define ports including standard an
35. to represent each character which allows non English characters and special characters to be represented concept check ka What is the difference between an analog and a digital signal ka What are decimal and binary systems How are they different GD Compare EBCDIC ASCII and Unicode Careers in IT Now that you know about system units l d like totell Computer technicians repair and install computer components and you about my career as a computer technician systems They may work on everything from personal computers and mainframe servers to printers Some computer technicians are responsible for setting up and maintaining computer networks Experienced computer technicians may work with computer engi neers to diagnose problems and run routine maintenance on com plex systems Job growth is expected in this field as computer equipment becomes more complicated and technology expands Employers look for those with certification in computer repair or associate degrees from professional schools Computer technicians also can expect to continue their education to keep up with tech nological changes Good communication skills are important in this field Computer technicians can expect to earn an annual salary in the range of 31 000 to 46 000 Opportunities for advancement typically come in the form of work on more advanced computer systems Some computer technicians move into customer service positions or go into sales
36. type of personal computer Most desktops have their system unit in a separate case This case contains the system s electronic compo nents and selected secondary storage devices Input and output devices such as a mouse keyboard and monitor are located outside the system unit This type of system unit is designed to be placed either horizontally or vertically Desktop system units that are placed vertically are sometimes referred to as a tower unit or tower computer See Figure 5 1 Some desktop computers like Apple s iMac have their monitor and system unit housed together in the same case These computers are known as an all in one See Figure 5 2 Laptops Although typically not as powerful as desktops laptops are portable and much smaller Their system units are housed with selected secondary storage devices and input devices keyboard and pointing device Located outside the system unit the monitor is attached by hinges Laptops are often called notebooks Figure 5 1 Tower unit Figure 5 2 All in one Ultrabooks also known as ultraportables or mini notebooks are a type of very portable laptop They are lighter and thinner and have a longer battery life than other laptops They accomplish these advantages by leaving out components such as optical drives and using energy efficient microprocessors See Figure 5 3 Tablets Tablets also known as tablet computers are the newest and one of the most pop ular types of co
37. uctions for a computer This information is called the system s BIOS basic input output system This information would include the spe PPF cifics concerning the amount of RAM and the type of keyboard mouse and secondary storage devices connected to the system unit If changes are made to the computer system these changes are reflected in flash memory To learn ROM more about how a computer starts up and BIOS visit our website at www Flash mhhe com ce2015 and select Student Edition then Explore and then Boot See Figure 5 13 for a summary of the three types of memory concept check ka What is memory Name and describe three types Ga What are cache memory DIMM and virtual memory ka Define ROM and flash memory Expansion Slots and Cards As previously mentioned many personal computers allow users to expand their systems by providing expansion slots on the system board Users can insert optional devices known as expansion cards into these slots See Figure 5 14 Ports on the cards allow cables to be con nected from the expansion cards to devices outside the sys tem unit See Figure 5 15 There are a wide range of different types of expansion cards Some of the most commonly used expansion cards are perrak RAM Use Programs and data Fixed start up instructions Flexible start up instructions Figure 5 13 Memory Slot e Graphics cards provide high quality 3 D graphics and ani f EEIE SME ay
38. vices Mobile devices handheld computers fit comfortably in one hand Smartphones are most popular type System unit is located behind the display screen Components Each type of system unit has the same basic compo nents including system board microprocessor and memory 130 CHAPTERS5 The system board mainboard or motherboard con trols all communication for the computer system All external and internal devices and components con nect to it e Sockets provide connection points for chips silicon chips semiconductors integrated circuits Chips are mounted on chip carriers e Slots provide connection points for specialized cards or circuit boards e Bus lines provide pathways to support communication To efficiently and effectively use computers you need to understand the functionality of the basic components in the system unit system board microprocessor memory expansion slots and cards bus lines ports and cables Additionally you need to understand how data and programs are represented electronically MICROPROCESSOR In most personal computers the central processing unit CPU or processor is contained on a single chip called the microprocessor It has two basic compo nents a control unit and ALU Microprocessor Chips A word is the number of bits that can be accessed by the microprocessor at one time Clock speed repre sents the number of times the CPU can fetch and pro cess data or instructio
39. y large programs are divided into parts and the parts are stored on a secondary device usually a hard disk Each part is then read into RAM only when needed In this way computer systems are able to run very large programs To learn more about how virtual memory works visit our website at www mhhe com ce2015 and select Student Edition then Explore and then Memory Terabyte TB 1 trillion bytes Figure 5 12 Memory capacity ROM Read only memory ROM chips have information stored in them by the manu facturer Unlike RAM chips ROM chips are not volatile and cannot be changed by the user Read only means that the CPU can read or retrieve data and pro grams written on the ROM chip However the computer cannot write encode or change the information or instructions in ROM Not long ago ROM chips were typically used to contain almost all the instruc tions for basic computer operations For example ROM instructions are needed to start a computer to access memory and to handle keyboard input Recently however flash memory chips have replaced ROM chips for many applications 120 CHAPTER5 Flash Memory Flash memory offers a combination of the features of RAM and ROM Like RAM it can be updated to store new information Like ROM it does not lose that infor mation when power to the computer system is turned off Flash memory is used for a wide range of applications For example it is used to store the start up instr
40. you To see more environmental facts visit our website at www mhhe ce2015 com and select Student Edition and then Environment 118 CHAPTER5 Figure 5 8 Chip mounted onto a chip carrier e Slots provide a connection point for specialized cards or circuit boards These cards provide expansion capability for a computer system For example a wireless networking card plugs into a slot on the system board to provide a connection to a local area network e Connecting lines called bus lines provide pathways that support communica tion among the various electronic components that are either located on the system board or attached to the system board Generally the system board found on a desktop is larger than that found on a laptop and much larger than one found on a tablet or a mobile device Although these system boards vary in size they nevertheless all perform the same function of communicating between the components of the personal computer concept check ka What is the system board and what does it do ka Define and describe sockets slots and bus lines ka What are chips How are chips attached to the system board Microprocessor In most personal computer systems the central processing unit CPU or processor is contained on a single chip called the microprocessor The micropro cessor is the brains of the computer system It has two basic components the control unit and the arithmetic logic unit e Co
41. ystem b board processor d system board 4 How many bytes can a 32 bit word computer access at one time a 1 c 8 b 4 d 16 5 In a personal computer system the central processing unit is typically contained on a single a bus c module b chip d RAM 6 This type of memory divides large programs into parts and stores the parts on a sec ondary storage device a direct c random access b expanded d virtual 7 Also known as NIC this adapter card is used to connect a computer to a n a AIA c graphics b expansion d network 8 This provides a pathway to connect parts of the CPU to each other a bus c wired b Plug and Play d wireless 9 The specialized port that connects musical instruments like an electronic keyboard to a sound card a eSATA c MIDI b HDMI d Thunderbolt 10 Computers can only recognize this type of electronic signal a analog c digital b bus d maximum For an interactive multiple choice practice test visit our website at www mhhe com ce2015 select Student Edition and choose Chapter 5 and then Multiple Choice 134 CHAPTER5 MATCHING Match each numbered item with the most closely related lettered item Write your answers in the spaces provided a cache ___ 1 Atype of multiprocessor chip that provides two or b flash more separate and independent CPUs c multicore __ 2 Atype of memory that is volatile or loses its d Plug and Play contents when power is turned off e por
42. zed FireWire devices such as camcorders and storage devices THE SYSTEM UNIT 123 e Ethernet ports are a high speed networking port that has become a standard for many of today s computers Ethernet allows you to connect multiple com puters for sharing files or to a DSL or cable modem for high speed Internet access Ethernet FireWire USB Specialized Ports In addition to standard ports there are numerous specialty ports includ ing eSATA HDMI MIDI MiniDP and Thunderbolt e External Serial Advanced Technology Attachment eSATA ports provide high speed connections for external hard disk drives optical discs and other large second Figure 5 19 Ports DVI HDMI VGA ary storage devices e High Definition Multimedia Interface HDMI ports provide high definition video and audio making it possible to use a computer as a video jukebox or an HD video recorder e Musical instrument digital interface MIDI ports are a special type of port for connecting musical instruments like an electronic keyboard to a sound card The sound card converts the music into a series of digital instructions These instructions can be processed immediately to reproduce the music or saved to a file for later processing e Mini DisplayPort MiniDP or mDP ports are an audiovisual port typi cally used to connect large monitors These ports are used with many Apple Macintosh computers e Thunderbolt ports first introduced in Ap
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