College of Computer and Information Science Chapter 6 The System Unit.

College of Computer and Information ScienceCollege of Computer and Information Science

Chapter 6

The System Unit

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Key Words & Terms• AC adapter:交流适配器• accelerated graphics port (AGP):加速图形端口• analog:模拟信号• Arithmetic Logic Unit (ALU):算术逻辑单元• arithmetic operation:算术运算• ASCII:一种八位键盘符号编码• binary coding scheme:二进制编码方案• binary system:二进制系统• bit:二进制位• bus:总线• bus line:总线• bus width:总线宽度• byte:字节• cable:电缆• cache memory:高速缓冲存储器• carrier package:载体• Central Processing Unit(CPU):中央处理器• chip:芯片• clock speed:时钟速度• complementary metal-oxide semiconductor (CMOS):互补金属氧化半导体

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Key Words & Terms• computer technician：计算机技术人员• control unit:控制单元• coprocessor: 协处理器• desktop system unit:台式机系统单元• digital:数字式• dial-core chip：双核芯片• EBCDIC:一种八位键盘符号编码• expansion bus:扩展总线• expansion card:扩展卡• expansion slot：扩展槽• FireWire bus:火线总线• FireWire port:火线端口• flash memory:闪存• graphics card:图形卡• graphics coprocessor:图形协处理器• handheld computer system unit:掌上型计算机系统单元• industry standard architecture(ISA):工业标准体系结构• Infrared Data Association (IrDA)：红外线传输器标准组织

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Key Words & Terms

• integrated circuit:集成电路• laptop:膝上型计算机• logical operation:逻辑运算• memory：内存• microprocessor：微处理器• modem card: modem卡• motherboard:主板• Musical Interface Digital Interface （ Music Instrument Data

Interface, MIDI ） :乐器数字界面• network adapter card:网络适配卡• network interface card (NIC):网络接口卡• notebook system unit:笔记本电脑系统单元• parallel port:并行端口• parallel processing:并行处理• PC card: PC卡

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Key Words & Terms• PCI Express : 快速 PCI• peripheral component interconnect (PCI) :外围设备连接端口• Personal digital assistant (PDA):个人数字化助理• Plug and Play:即插即用• port:端口• power supply unit:供电单元• processor:处理器• random-access memory (RAM):可读写内存• read-only memory (ROM):只读内存• RFID tag ： RFID 标签• semiconductor:半导体• serial port:串行端口• silicon chip:硅芯片• slot:插槽• smart card:智能卡

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Key Words & Terms• socket:插口• sound card：声卡• system board:系统板• system bus:系统总线• system cabinet:机箱• system clock:系统时钟• system unit:系统单元• tablet PC system unit: tablet PC 系统单元• TV tuner card:电视调协卡• unicode:十六位字符编码• universal serial bus (USB):通用串行总线• universal serial bus (USB) port:通用串行总线端口• virtual memory:虚拟内存• word:字

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Competencies (1 of 2)

• Describe the four basic types of system units• Discuss how a computer uses binary codes

to represent data in electronic form• Describe each of the major system unit

components• Discuss microprocessors, including

specialty processors• Describe the different types of memory

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Competencies (2 of 2)

• Discuss expansion slots and boards• Describe the five principal types of

expansion buses• Discuss the four standard ports

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Introduction

Speed, capacity, and flexibility determine the power of microcomputers. Knowledge of a computer’s power allows you to make good buying decisions and to determine if your current system will run new applications. Competent end users need to understand the basic principles of how microcomputers are put together. These principles will be covered in this chapter.

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System Unit

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System Unit Types

• Desktop System Units

• Notebook System Units

• Tablet PC System Units

• Handheld Computer System Units

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Electronic Data and Instructions

• Data and instructions are represented electronically

• Two-state system or Binary System– Off/on electrical states– Characters represented by 0s (off) and 1s (on)– Bits– Bytes

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Binary Coding Schemes

• Three types of binary coding schemes– ASCII - American Standard Code for Information

Exchange– EBCDIC - Extended Binary Coded Decimal

Interchange Code – Unicode – handles languages with large numbers

of characters

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System Board

• Connects all components• Allows communication between devices • Main board or motherboard• Circuit board

electronic components– Sockets– Slots– Bus lines

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Microprocessor

• Central Processing Unit (CPU)• Two Basic Components

– Control unit– Arithmetic-logic unit (ALU)

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Microprocessor Chips

• Chip capacities are expressed in word sizes • Two Recent Significant Developments

– 64-bit processors• Becoming more commonplace• Windows XP Professional X64 Edition

– Dual-Core Chips• Can provide two separate and independent CPUs• Parallel processing

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Specialty Processors • Coprocessors

– Designed to improve specific computing operations– Graphics coprocessors

• Smart cards– Credit card sized with an embedded chip– Used by many universities

• RFID tags– Information chips– Used for tracking purposes

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Memory

• Holding area for data, instructions, and information

• Memory is contained on chips connected to the system board

• Types of memory chips– RAM – ROM– CMOS

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RAM

• Random Access Memory (RAM) chips hold the program and data– Cache memory or RAM cache– Flash RAM or flash memory

• Other types of RAM– DRAM– SDRAM– DDR– Direct RDRAM

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Return

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ROM

• Read-only memory (ROM) chips are not volatile and cannot be changed by the user

• CPU can read, or retrieve data and programs but the computer cannot write

• Contain special instructions– Needed to start a computer– Give keyboard keys their special capabilities– Put characters on screen

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CMOS

• Complementary metal-oxides semiconductor (CMOS) chips provide flexibility for a computer system

• Contains essential information every time the computer is turned on– Date and time– Amount of RAM– Type of keyboard

• Content can be changed to reflect changes in the computer system

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System Clock

• Important measurement indicating speed – Located on a small chip– Produces electrical beats

• Synchronizes operations• Expressed in gigahertz (GHz)

(billions of beats per second)• Faster clock speed, faster computer

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Expansion Slots and Cards

• Allow for new devices to be added– Open architecture– Slots provide for expansion

• Expansion cards are also called …– Plug-in boards– Controller cards– Adapter cards– Interface cards

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Commonly Used Expansion Cards

• Graphics cards• Sound cards• Modem cards• Network interface cards (NIC)• PC cards (PCMCIA cards)• TV tuner cards

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TV Tuner Cards AndVideo Clips

• Allows you to view your favorite TV shows while running other applications such as Excel

• Video can be captured to a file, added to a Web page, attached to an email, or added to a class presentation

• Relatively inexpensive and

easy to install

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Plug and Play

• Set of hardware and software standards developed by Intel, Microsoft, and others

• Creating devices that are able to configure themselves when installed

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Bus Lines

• Connect parts of the CPU to each other • Data roadway for traveling bits

– Measured as bus width– More lanes, faster traffic

• Two basic categories– System buses– Expansion buses

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Expansion Buses

• Connects the CPU to other components on the system board, including expansion slots

• Principal types– Industry Standard Architecture (ISA) – Peripheral Component Interconnect (PCI)– Accelerated Graphics Port (AGP)– Universal serial bus (USB)– FireWire buses (HPSB)

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Ports

• Socket for connecting external devices

• Ports can connect directly to the system board or they can connect to cards that are inserted into slots on the system board

• Two Types– Standard Ports– Specialized Ports

Ports

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Cables

• 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 connector that is attached to a matching connector on the port

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Power Supply

• Computers require direct current (DC)• DC power provided by converting alternating

current (AC) from wall outlets or batteries • Desktop computers use power supply units• Notebooks and handhelds use AC adapters

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A Look to the FutureXybernaut Corporation

• Wearable computers• Send and receive

email• Maintain your

personal schedule book

• Play interactive games and surf the Web from anywhere

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Discussion Questions

• Describe the four basic types of system units.

• Describe the two basic components of the CPU.

• What are the differences and similarities between the three types of memory?

• Identify five expansion cards and describe the function of each.

• Identify and describe four standard ports and two specialized ports.

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Crossword Puzzle Answers:

Across

Num.

Clue Answer

6 Assists with the installation of expansion cards.

Plug and Play

8 Memory which improves processing by acting as a temporary high-speed holding area between memory and the CPU.

Cache

10 Controls the speed of operations.

System Clock

Down

Num. Clue Answer

1 Part of a microcomputer that contains the CPU.

System Unit

2 Controls and manipulates data to produce information.

Microprocessor

3 The number of bits that can be accessed by the microprocessor at one time.

Word

4 Holding area for data, instructions, and information.

Memory

5 Used to connect external devices to system unit via ports.

Cable

7 Unit consisting of eight bits. Byte

9 Most widely used microprocessor binary coding scheme.

ASCII

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Answers for Multiple Choice and Matching

Num Multiple Choice Answers Matching Answers

1 D J

2 B A

3 C C

4 B H

5 B G

6 A I

7 A D

8 C E

9 B F

10 C B

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End of Chapter 6