信息处理技术. chapter 2: computer hardware2 111chapter 4: file management, virus protection,...

信息处理技术信息处理技术

Chapter 2: Computer Hardware 2111Chapter 4: File Management, Virus Protection, and Backup

1Chapter 1: Computer, Internet, Web, and E-Mail Basics

Chapter 2: Computer Hardware 3

After this chapter, you should be able to:– Explain why most computers are digital– 解释为什么大多数计算机是数字化的？解释为什么大多数计算机是数字化的？– Describe the role of the ALU– 描述描述 ALU(ALU(算数逻辑运算单元算数逻辑运算单元 ))的作用的作用– List factors that affect performance– 列举决定计算机性能的因素列举决定计算机性能的因素– Explain RAM 解释解释 RAMRAM

– Compare storage technologies– 比较不同的存储技术比较不同的存储技术

Chapter 2 Preview 第二章预览第二章预览


After this chapter, you should be able to:– Explain the factors that might help a shopper

decide whether to purchase a CRT, LCD, or plasma monitor

– 说明可以帮助购买者选择是否购买阴极射线管说明可以帮助购买者选择是否购买阴极射线管 \\液晶液晶 \\等离等离子显示器的原因子显示器的原因

– Compare and contrast the technologies and applications for printers

– 对比、比较打印机的技术原理及应用范围对比、比较打印机的技术原理及应用范围– Describe computer’s expansion bus– 描述计算机的扩充总线描述计算机的扩充总线 – Explain hardware compatibility

considerations– 解释硬件兼容性的考虑因素解释硬件兼容性的考虑因素

Chapter 2 Preview


Chapter 2 Outline

• Section A 数的定义– Data Representation and Digital

Electronics

• Section B 微处理器和主存– Microprocessors and Memory

• Section C 存储设备– Storage Devices

• Section D – Input and Output Devices 输入输出设备


Chapter 2 纲要

• Section A– 数据表示法及数字电子学数据表示法及数字电子学

• Section B– 微处理器及主存微处理器及主存

• Section C– 存储设备

• Section D– 输入及输出设备

Computer Concepts 8th Edition

Chapter 2Computer Hardware

Section A: Data Representation and Digital Electronics数据表示法及数字电子学数据表示法及数字电子学


• Data representation makes it possible to convert letters, sounds, and images into a form computers can use for processing

• A digital device/ 数字设备数字设备 //works with discrete 离散的 data, such as the digits 1 and 0

• An analog device/ 模拟设备模拟设备 / works with continuous data

Data Representation: How do computers represent data digitally?

计算机如何表示数字化的数据计算机如何表示数字化的数据 ??

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• Computers are digital • Just as a standard light switch is a

simpler technology than a dimmer( 调光调光器器 ), so is digital when compared to analog(( 模拟模拟 ))

Data Representation: How do computers represent data digitally?

digital analog

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• The binary number system (base 2) uses only two digits 0, and 1

• The following table lists some decimal numbers and their binary equivalent:

How does a computer represent numbers?

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• Character data is composed of(( 由由……组组成成 )) letters, symbols, and numerals that are not used in arithmetic operations

• ASCII requires only 7 bits for each character

• Extended ASCII uses 8 bits to represent each character

How can a computer represent words and letters using bits?计算机如何用二进制位表示字符及词汇计算机如何用二进制位表示字符及词汇

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• EBCDIC is an alternative/ 可选择的可选择的 / 8-bit used by older IBM systems

• Unicode uses 16 bits and provides codes for 65,000 characters – Used for foreign language support

How can a computer represent words and letters using bits?

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• Sounds and pictures must be transformed into a format the computer can understand

• A computer must digitize (( 数字数字化化 ))colors, notes (( 音符音符 )), and instrument sounds （器乐）（器乐） into 1s and 0s

How does a computer convert sounds and pictures into codes? 计算机如何将声音、图片转为代码？计算机如何将声音、图片转为代码？

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• A bit is one binary digit (b)– 0

• A byte is 8 bits (B)– 0010 0100

Quantifying Bits and Bytes: How can I tell the difference between bits and bytes?位及字节的量化：如何区别位及字节？位及字节的量化：如何区别位及字节？

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• Kilo- means a 1000, Mega[] 百万百万 - means million, Giga 十亿十亿 -means billion

• Kilobit (Kb) is 1,024 bits

• Kilobyte (KB) is 1, 024 bytes

• Megabyte (MB) is 1,048,576 bytes

• Gigabyte (GB) is 1,073,741,824 bytes

Quantifying Bits and Bytes: How can I tell the difference between bits and bytes?

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How does a computer store and transport all these bits? 计算机如何存储及传输二进制位？计算机如何存储及传输二进制位？• Bits take the form of electrical pulses that

can travel over circuits• 二进制位被处理成能够在电路上传输的电脉冲的形式二进制位被处理成能够在电路上传输的电脉冲的形式• This is almost the same way as electricity

flows over a wire when you turn on a light switch

• 有线传输中的电流信号与转换为光信号几乎用同样的有线传输中的电流信号与转换为光信号几乎用同样的方式传输方式传输

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• Desktop units are designed with expectation/ 可扩充可扩充 / that the home user may add or update the equipment

• Small desktop and notebook computers are not designed for users to access all areas

What’s inside the system unit?主机单元中有哪些设备？

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What’s inside the system unit?

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• Most electronic components inside a computer are integrated circuits(( 集成电路集成电路 ))

– Thin slices of silicon crystal packed with microscopic circuit elements

– 薄的硅晶片被封装成精微的电子电路薄的硅晶片被封装成精微的电子电路

What’s a computer chip?

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• Semiconducting materials(( 半导体材料半导体材料 )) are used to fabricate(( 制成制成 )) a chip

• Types of chips:– DIPs Double In-line Package Double In-line Package 双列直插式组装双列直插式组装– DIMMs Doul in-line memory modDoul in-line memory mod 双边接触内存模组双边接触内存模组– PGAs pin-grid arraypin-grid array 引脚网格阵列引脚网格阵列– SEC cartridge single edge contact cartridges single edge contact cartridges

单边连接器单边连接器


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• The system board (( 主板主板 & be intituled & be intituled

mother board in Taiwan,China) mother board in Taiwan,China) houses all essential 基本的基本的 chips and provides connecting circuitry between them

How do chips fit together to make a How do chips fit together to make a computer?computer? 芯片如何组合成为计算机？芯片如何组合成为计算机？

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How do chips fit together to make a computer?

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Section B: Microprocessors and Memory

微处理器微处理器 && 主存主存


• An integrated circuit designed to process instructions 为处理指令而设计的集成电路为处理指令而设计的集成电路– CPU on a chip

Microprocessor Basics:What exactly is a microprocessor?

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Pentium 4

Die photo of the Intel® Pentium® 4 Processor built on 90nm technology


Chicago, IL

Satellite image of Chicago

Which is more complex?


• The CPU has two parts• ALU (arithmetic logic unit) 算术逻辑运算单算术逻辑运算单

元元– Performs arithmetic operations– Performs logical operations– Uses registers to hold data being processed

• The CPU’s control unit directs 串行串行 and coordinates 并行并行 processing

How does a microprocessor work?

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• Technically yes, but most computer owners rarely do

• 技术上可行，但大多数计算机用户很少这样做技术上可行，但大多数计算机用户很少这样做

• Reasons not to upgrade– Cost– Technical factors – speed

• Do research before you upgrade your microprocessor

Can I replace my computer’s Can I replace my computer’s microprocessor with a faster one?microprocessor with a faster one?能够为计算机更换更快的处理器吗？能够为计算机更换更快的处理器吗？

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• A temporary holding area for data, application program instructions, and the operating system

• 一个为数据、应用程序指令及操作系统提供一个为数据、应用程序指令及操作系统提供的临时存储区域的临时存储区域– As you type, characters are held in RAM

Random Access Memory: What is RAM?什么是随机存储器？

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• RAM is primary storage (main memory)– Measured in megabytes (MB) or gigabytes (GB)

• Today’s computers have between 128 MB and 2 GB of RAM

• Depends on software you use• You can purchase additional RAM• A computer can use disk storage to simulate

RAM. This is called virtual memory 虚拟内虚拟内存存– Not as fast as RAM

How much RAM does my computer need?

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• No. RAM components vary in speed, technology, and configuration

• Speed is measured in nanoseconds 纳秒纳秒 . 1 nanosecond (ns) is 1 billionth of a second– It can also be expressed in MHz (millions of

cycles per second)

• SDRAM (Synchronous Dynamic RAM)• RDRAM (Rambus Dynamic RAM)

Do all computers use the same type of RAM?

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• Type of memory circuitry that holds the computer’s startup routine/ 引导程序 /

• Permanent and non-volatile/ 永久且不可变 /

• Only way to change the instructions on a ROM chip is to replace the chip

Read-Only Memory: How is ROM different from RAM?

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• A computer needs a semi-permanent way of keeping boot data

• CMOS memory holds data but requires very little power to retain its contents– Retains important computer settings after

you turn the power off– Can run by a battery on the system board

CMOS Memory: Where does a computer store its basic hardware settings?CMOSCMOS ：存储计算机硬件的基本设置信息：存储计算机硬件的基本设置信息

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Where does a computer store its basic hardware settings?

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How do I get the best computer for my money?

• Different buyers have different needs

• Assess your budget and think about how you plan to use your computer

• Look at ads and visit online computer stores

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Section C: Storage Devices


• A storage medium 存储媒体储媒体 is the disk, tape, CD, DVD, paper or other substance that contains data

• A storage device 存储设备储设备 is the mechanical appa’ratus 设备设备 that records and retrieves 恢复恢复 data from a storage medium

Storage Basics: What are the basic components of a data storage system?存储系统的基本组成构件是什么？存储系统的基本组成构件是什么？

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• Stores data by magnetizing microscopic particles// 粒子粒子 // on the disk or tape surface

• Read-write head - mechanism in the disk drive that reads and writes magnetized particles that represent data

How does magnetic storage work? 磁存储设备如何工作 ?

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How does magnetic storage work?

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• Stores data as microscopic light spots (lands 平面平面 ) and dark spots (pits 坑坑 ) on the disk surface

• Less susceptible// 易受影响易受影响 // to environmental damage than data recorded on magnetic media

How does optical storage work?

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How does optical storage work?

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How does solid state storage work?

• Stores data in a non-volatile, erasable, low-power chip

• Some solid state storage requires a device called a card reader to transfer data to or from a computer

• Provides faster access to data than magnetic or optical storage technology because it includes no moving parts

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• Devices can be added into empty drive bays 驱动器支架驱动器支架

Can I add storage devices to my computer?

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• A floppy disk is a round piece of flexible mylar 聚脂薄膜聚脂薄膜 plastic 塑胶塑胶 covered with a thin layer of magnetic oxide 氧化物氧化物 and sealed inside a protective casing

What is floppy disk technology?

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• HD DS 3½” diskettes have capacity of 1.44 MB

• Zip disks come in 100 MB, 250 MB, and 750 MB versions

How much data can a HD DS disk and a Zip disk hold?

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• Major advantage – portability• Major disadvantage – not a particularly

speedy device and limited storage capacity

• Slowly being replaced by solid state technology

• Today most software vendors use CD-ROM or DVD-ROM disks instead

What are the advantages and disadvantages of HD DS floppy disks?

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• Disk density 密度密度 – closeness 狭窄狭窄 and size of magnetic particles on the disk’s surface

• Zip disks store data at a higher density than a standard 3½” floppy disk

How can ZIP disks store more data than standard floppy disk?

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• Hard disk platter 碟面碟面 - a flat, rigid 刚性的刚性的 disk made of aluminum 铝铝 or glass and coated with magnetic iron oxide particles– Density far exceeds floppy disk

• Hard disk - one or more platters 盘盘 and their associated 相联系的相联系的 read-write heads– Preferred type of main storage

• Miniature hard drives 微硬盘微硬盘 store 20 to 40 GB

How does a hard disk work?

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How does a hard disk work?

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• Head crash - when a read-write head runs into a dust// 灰尘灰尘 // particle or other contaminant // 污染物污染物 //on the disk– Head crash damages some data on disk– Triggered by jarring 震动触发的震动触发的 the hard

disk while in use – Not limited to hard disks

What’s the downside of hard disk storage?

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• Tape backup - copy of data on hard disk stored on magnetic tape

• Relatively inexpensive

• Primarily used on business computers

• Not suitable for everyday storage tasks

• Sequential-access 顺序访问顺序访问 storage medium

Tape Storage: What’s the purpose of a tape drive?

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• CD– Holds up to 80 minutes of music or 700

MB of data

• DVD– Holds about 4.7 GB of data– A double layer DVD has two recordable

layers on the same side and can store 8.5 GB of data

CD and DVD technology: Is there a difference between CD and DVD technology?

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How do CD and DVD drives work?

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Optical Media


• Recordable technology 记录技术记录技术 uses a laser to change the color in a dye 染染色色 layer sandwiched beneath the clear plastic disk surface

• Rewritable technology uses “phase change 相位转换相位转换” technology to alter a crystal 晶体晶体 structure on the disk surface

How do CD and DVD drives work?

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Can I use a single drive to work with any CD or DVD media?

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• It is slower than hard disk access

• Not yet a suitable replacement

Are rewritable CD or DVD drives an acceptable replacement for a hard disk?

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• Not exactly– Movie files are still very large– Television DVD drives include MPEG

decoding circuitry

Is my computer DVD drive the same as the one connected to my TV?

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• Portable// 轻便的轻便的 /,/, provides fast access to data and uses very little power– USB flash drive– CompactFlash card– MMC– SecureDigital– SmartMedia

Solid State Storage: When would I use solid state storage?

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RAMCPU

Regusters

cacheROM

VRAM

Hard Drive

Tape

Magnetic Storage

CD

DVD

Optical Storage

USB

network

Storage Review



Section D: Input and Output Devices

输入输出设备输入输出设备


Basic Input Devices: What devices can I use to get data into a computer?

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• CRT (cathode ray tube) 阴极射线管• LCD (liquid crystal display) 液晶显示

– LCDs are clearer, have low radiation emission, are portable, and compact

– LCDs are also more expensive than CRTs

What are my options for display devices?What are my options for display devices?如何选择显示设备如何选择显示设备 ??

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What are my options for display devices?

• Plasma 等离子 screen technology– Lightweight, compact, and more expensive

than CRT monitors

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IBM’s Flexible Display (in development)

http://www.universaldisplay.com/foled.htm






Wearable display


How does an ink jet printer work? 喷墨打印机工作原理喷墨打印机工作原理

• Nozzle-like/ 喷管样 / print head that sprays ink onto paper to form characters and graphics

• Most ink jet printers use CMYK color

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CMYKCMYK

用于印刷的四分色 (Cyan 青 , Magenta 品红 , Yellow 黄 , Black 黑 )


• A laser printer paints dots of light on a light-sensitive drum– Higher quality than ink jet – More expensive to buy than ink jet– Less expensive to operate than ink jet

How do laser printers compare to ink jet printers?

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How do laser printers compare to ink jet printers?

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• Produce characters and graphics by using a grid of fine wires– Introduced in 1970s– Low quality output– Used for “back-office” applications that

demand low operating cost and dependability

– Can print multipart carbon forms

What is a dot matrix printer? 什么是点阵打印机什么是点阵打印机 ??

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What is a dot matrix printer?

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• Thermal transfer 热传递 printer– Uses page-sized ribbons coated with wax– Print head consists of heating elements to

melt the wax

• Dye 染色剂 sublimation []升华printer– Similar to wax 蜡 , but page-sized ribbon 带子 contains dye

– Print heads diffuse 弥漫 the dye

What other printer technologies are available?

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• Resolution辨析率– Measured in dpi (dots per inch)

• Print speed– Measured either by pages per minute

(ppm) or characters per second (cps)• Color takes longer than black and white• Text prints faster than graphics

Printers: What features should I look for in a printer?

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• Duty cycle工作 [ 负载 ] 循环 - indication of the number of pages a printer can be expected to print per month

• Indicates maintenance costs• Operating costs

– Printers require ongoing costs including ribbons, ink cartridges, and toner

– Per copy cost is the cost of printing a page with an average amount of text, graphics, and color

What features should I look for in a printer?

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• Duplex capability 双面打印能力– A printer with duplex capability can print on both

sides of the paper

• Memory– A computer sends data for a printout to the

printer along with a set of instructions on how to print the data

What features should I look for in a printer?

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• Internal devices– Tools required

• Screwdriver 螺丝起子• Directions 说明 ( 书 )

– Before installing• Unplug the computer 打开计算机• Ground yourself 接地放电

– Installing• Follow the directions 按照说明书安装

Installing Peripheral Devices: Is it difficult to install a new peripheral device?

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• Expansion slot 扩充槽 - long, narrow socket on the system board into which you can plug an expansion card

• Expansion card 扩充卡 - small circuit board that provides computer with ability to control storage, input or output device

What’s an expansion slot?

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• ISA (Industry Standard Architecture)– Used today only for some modems and other

relatively slow devices

• PCI (Peripheral Component Interconnect)– Offers fast transfer speeds and a 32-bit or 64-bit

data bus

• AGP (Accelerated Graphics Port)– Provides a high-speed data pathway primarily

used for graphics cards

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• Equipped with a special type of external slot called a PCMCIA slot

• Typically a notebook only has one slot, but the slot can hold more than one PC card (PCMCIA expansion cards)

• PCMCIA [PCMCIA [ 计计 ] ] 个人计算机存储卡国际协会个人计算机存储卡国际协会

Do notebook computers contain expansion slots?

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• Used to connect a peripheral device

• Expansion port - any connector that passes data in and out of a computer or peripheral device

What is an expansion port?

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What is an expansion port?

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How do I know which cable to use? Serial

DB-9

ParallelDB-25M

USB

SCSIC-50F

IEEE 13394

VGAHDB-15

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SCSI SCSI 小型计算机系统接口小型计算机系统接口

IEEEIEEE 电气和电子工程师协会电气和电子工程师协会

VGAVGA视频图形阵列视频图形阵列

USB Universal Serial Bus USB Universal Serial Bus Intel Intel 公司开发的通用串行总线架构公司开发的通用串行总线架构


You should now be able to:– Explain why most computers are digital– Describe the role of the ALU– List factors that affect performance– Explain RAM– Compare storage technologies– Describe computer’s expansion bus– Explain hardware compatibility

considerations

Conclusion


本章学习完后 , 应具备下述能力 :–解释计算机的数字化–描述 ALU的作用–列举计算机性能的影响因素–解释 RAM–比较存储技术–解释计算机扩充总线–解释硬件兼容性

结论 :

信息处理技术. chapter 2: computer hardware2 111chapter 4: file management, virus protection,...

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