计算机专业英语第3版unit1.ppt

计算机专业英语第3版unit1内内 容容 简简 介介 本书共分本书共分6个单元，个单元，第第1单元单元介绍计算机硬件基介绍计算机硬件基础，分别讲述处理器、存储器和输入础，分别讲述处理器、存储器和输入/输出技术。输出技术。第第2单元单元是计算机软件知识部分，内容有是计算机软件知识部分，内容有C语言、数语言、数据结构、操作系统、编译原理及数据库技术。据结构、操作系统、编译原理及数据库技术。第第3单元单元是多媒体及应用方面的知识，包括多媒体、图是多媒体及应用方面的知识，包括多媒体、图形图像、形图像、CAD、计算机动画和多媒体应用软件。、计算机动画和多媒体应用软件。第第4单元单元是计算机网络相关知识介绍，包括计算机网是计算机网络相关知识介绍，包括计算机网络基础、互联网搜索引擎、无线网络技术及网络安络基础、互联网搜索引擎、无线网络技术及网络安全。全。第第5单元单元讲述电子商务方面的内容，有电子商讲述电子商务方面的内容，有电子商务基础、务基础、EDI和网络广告。和网络广告。第第6单元单元是计算机领域是计算机领域新技术介绍，包括人工智能、虚拟现实和神经网络。新技术介绍，包括人工智能、虚拟现实和神经网络。6/2/20242Unit 1 Hardware Basics1.1 Central Processing Unit1.2 Memory1.3 Input/Output Systems6/2/202431.1 Central Processing Unit The CPU is the heart of the computer system.It is responsible for performing all arithmetic operations and logic decisions initiated by the program.The CPU coordinates all the activities of the various components of the computer.It determines which operations should be carried out and in what order.6/2/20244Block diagram of a digital computer 6/2/20245Three basic capabilities of computersFirst,computers have circuits for performing arithmetic operations,such as:addition,subtraction,division,multiplication and exponentiation.Second,computers have a means of communicating with the user.Third,computers have circuits which can make decisions.6/2/20246The control unit The control unit is the functional unit that is responsible for supervising the operation of the entire computer system.The control unit fetches instructions from memory and determines their type or decodes them.It then breaks each instruction into a series of simple small steps or actions.By doing this,it controls the step-by-step operation of the entire computer system.6/2/20247The Arithmetic/Logic Unit Data are brought into the ALU by the control unit,and the ALU performs whatever arithmetic or logic operations are required to help carry out the instructions.Arithmetic operations include adding,subtracting,multiplying,and dividing.Logic operations make a comparison and take action based on the results.6/2/20248Registers A register is a storage location inside the processor.Registers in the CPU are used to store the current instruction,the location of the next instruction to be executed,and the operands.6/2/20249Instruction An instruction is made up of operations that specify the function to be performed and operands that represent the data to be operated on.When the operands are stored in the computers memory,they have an address to indicate where they are.6/2/202410The steps of executing each instructionFetch the next instruction from memory into the instruction register.Change the program counter to point to the following instruction.Determine the type of instruction just fetched.If the instruction uses data in memory,determine where they are.Fetch the data into internal CPU registers.Execute the instruction.Store the results in the proper place.Go to step 1 to begin executing the following instruction.6/2/202411Key Words address 地址，寻址analogous 类似的，相似的arithmetic 算术的auxiliary 辅助的，补充的awesome 惊人的，令人敬畏的capability 性能，能力decode 解码，译码distinguish 区别，辨别exponentiation 幂运算fetch 获取，取得fraction 小部分initiate 开始，启发，提议，创始instantaneously 瞬间地，即时地instruction 指令6/2/202412Key Words keyboard 键盘mainframe 大型机manipulation 操作，处理microelectronic 微电子的operand 操作数originality 创意，创造力retrieve 恢复remarkable 显著的，不平常的sequence 顺序，序列silicon 硅transistor 晶体管6/2/202413Notes 1 Although most CPU chips are smaller than a lens of a pair of glasses,the electronic components they contain would have filled a room a few decades ago.本句由“Although”引导让步状语从句，“the electronic components”作主语。译文：虽然大多数CPU芯片比一块眼镜片还小，但所包含的电子元件在几十年前却要装满一个房间。6/2/202414Notes 2 The program,which tells the computers what to do and the data,which provide the information needed to solve the problem,are kept inside the computer in a place called memory.这里的主语是“the program and the data”，由which引导的两个定语从句分别修饰the program和the data。译文：程序的作用是指示计算机如何工作，而数据则是为解决问题提供的所需要的信息，两者都存储在存储器里。6/2/202415Notes 3 The Arithmetic/Logic Unit(ALU)is the functional unit that provides the computer with logical and computational capabilities.本句由“that”引导定语从句，修饰“the functional unit”。译文：算术逻辑单元（ALU）是为计算机提供逻辑及计算能力的功能部件。6/2/202416Notes 4 For example,if an instruction is to perform the operation of adding two numbers,it must know what the two numbers are and where the two numbers are.这里的“what the two numbers are and where the two numbers are”作宾语，它由两个并列的从句组成。译文：例如，一条指令要完成两数相加的操作，它就必须知道：这两个数是什么？这两个数在哪儿？6/2/202417Notes 5 A timer called a clock releases precisely timed electrical signals that provide a regular pulse for the processors work.本句中的“that provide a regular pulse for the processors work”修饰electrical signals。译文：一个称做时钟的计时器准确地发出定时电信号，该信号为处理器工作提供有规律的脉冲信号。6/2/202418Translation Exercises1.集成电路 integrated circuit2.取指译码执行 fetch-decode-execute3.算术逻辑运算 Arithmetic Logical Operations4.微电子技术 microelectronic techniques5.数字计算机系统 digital computer system6.辅助存储器 auxiliary storage7.工作区 workspace8.逻辑决策 logic decisionp6/2/202419Translation Exercises1.Central Processing Unit 中央处理器2.functional unit 功能单元3.current instruction 当前指令4.instruction register 指令寄存器5.program counter 程序计数器6.electronic components 电子元件7.input information and commands 8.输入信息和指令8.Arithmetic/Logic Unit 算术逻辑单元6/2/202420Reading Material:MicroprocessorMicrocomputer,or micro for short,is a kind of computers.It was born in the early 1970s.the microprocessor is built as a single semiconductor device;that is,the thousands of individual circuit elements necessary to perform all the logical and arithmetic functions of a computer are manufactured as a single chip.6/2/202421Reading Material:MicroprocessorComputer programs tell the microprocessor what to do,which is how everything works inside a PC.Other terms for the microprocessor include the processor;the central processing unit（CPU）;and the number of the microprocessor,such as 8088,80286,80386,80486,and so on.6/2/2024221.2 MemoryA systematic arrangement of memory cells constitutes a memory.Two basic types of semiconductor memory are considered.The first is the Random Access Memory(RAM),a read-write memory,in which each individual cell can be addressed at any particular time.A second class of semiconductor memory is the Read-Only Memory(ROM).The set of data in this type of memory is generally considered to be fixed.6/2/202423SRAM and DRAMTwo type of RAM are the static RAM(SRAM)and dynamic RAM(DRAM).A static RAM consists of a basic bi-stable flip-flop circuit that needs only a dc current or voltage applied to retain its memory.A dynamic RAM is an MOS memory that stores one bit of information as charge on a capacitor.6/2/202424Types of ROM The first is programmed either by the manufacturer(mask programmable)or by the user(programmable,or PROM).Once the ROM has been programmed by either method,the data in the memory are fixed and cannot be altered.The second type of ROM may be referred to as an alterable ROM in that the data in the ROM may be reprogrammed if desired.This type of ROM may be called an EPROM(erasable programmable ROM),EEPROM(electrically erasable PROM),or flash memory.6/2/202425Basic memory architecture 6/2/202426Memory ContentsMemories consist of a number of cells,each of which can store a piece of information.Computer memory is measured in kilobytes or megabytes of information.A byte is the amount of storage needed to hold one character,such as a letter or a numeric digit.One kilobyte(KB)equals 1024 bytes,and one megabyte(MB)is about 1 million bytes.Software requires the correct amount of RAM to work properly.6/2/202427Memory Address Computers that use the binary number system also express memory addresses as binary numbers.If an address has m bits,the maximum number of cells directly addressable is 2m.6/2/202428Key Wordsadjacent 邻近的，接近的allocate 分配，分派capacitor 电容configuration 结构consecutive 连续的，连贯的etch 蚀刻hexadecimal 十六进制的implicit 暗示的，绝对的individual 个别的，独特的kilobyte 千字节megabyte 兆字节6/2/202429Key Wordsmillisecond 毫秒non-metallic 非金属的nonvolatile 非易失性的octal 八进制的organization 组织programmable 可编程的semiconductor 半导体significance 重要性，意义stable 稳定的standardize 标准化virtually 事实上6/2/202430Notes 1 The number of bits in the address is related to the maximum number of directly addressable cells in the memory and is independent of the number of bits per cell.本句中，of directly addressable cells in the memory修饰the maximum number。译文：地址的位数与存储器可直接寻址的最大单元数量有关，而与每个单元的位数无关。6/2/202431Notes 2 Thus a 16-bit words,whereas a 32-bit machine will have 32-bit registers and instructions for moving,adding,subtracting,and otherwise manipulating 32-bit words.Thus a 16-bit words是一个省略句，这里的whereas作“而”讲。译文：因而16位机器具有16位的寄存器和指令以实现16位字的操作；32位机器则有32位的寄存器和指令，以实现传送、加法、减法和其它他32位字的操作。6/2/202432Notes 3 This was the ability to etch thousands of integrated circuits onto a tiny piece(chip)of silicon,which is a non-metallic element with semiconductor characteristics.由which引导的是非限定性定语从句，用来修饰silicon。译文：这就是将成千上万个集成电路蚀刻在一小块硅（芯）片上的能力。硅片是具有半导体特性的非金属元件。6/2/202433Notes 4 To access expanded memory,a program needs to communicate with the EMM.本句中的“To access expanded memory”作目的状语。译文：为了访问扩展存储器，程序需要与EMM联系。6/2/202434Notes 5 When a program allocates expanded memory pages,the EMM returns a handle to the requesting program.本句中，由“when”引导时间状语从句。译文：当一个程序装入扩展存储器页中时，EMM就将一个标志回复给这个请求程序。6/2/202435Translation Exercises1.易失性存储器 volatile memory2.外围电路 peripheral circuit3.实模式 the real mode4.寻址能力 address ability5.闪存 flash memory6.刷新电路 refresh circuitry7.只读存储器 Read Only Memory8.随机存取存储器 Random Access Memory6/2/202436Translation Exercises1.periodic refresh 定期刷新2.software interrupt 软件中断3.binary number 二进制数字4.electrically erasable PROM 5.电可擦除可编程的只读存储器5.expanded memory 扩展存储器6.erasable programmable ROM 可擦除可编程的只读存储器7.refresh cycle 刷新周期8.logical page 逻辑页面6/2/202437Reading Material:Cache and Magnetic Disks A variety of different types of cache（disk cache,memory cache,processor cache）can improve overall system performance.A cache can be optionally implemented on almost any system.Cache controllers have been used on mainframe computer systems for many years;their migration to the micro could be seen as a logical next step.6/2/202438Reading Material:Cache and Magnetic DisksThere are two major types of magnetic disks:floppy disks and hard disks.Both types of disks rely on a rotating platter coated with a magnetic surface and use a moveable read/write head to access the disk.Disk storage is nonvolatile,meaning that the data remains even when power is removed.6/2/202439Reading Material:Cache and Magnetic DisksTo access data,the operating system must direct the disk through a three-stage process.The first step is to position the arm over the proper track.This operation is called a seek,and the time to move the arm to the desired track is called seek time.Once the head has reached the correct track,we must wait for the desired sector to rotate under the read/write head.This time is called the rotation latency or rotational delay.The last component of a disk access,transfer time,is the time to transfer a block of bits,typically a sector.6/2/2024401.3 Input/Output Systems You can use your keyboard for many purposes:pTyping informationpEntering numbers with the numeric keypadpRequesting specific functionspPerforming system functions with key combinationspMoving around the computer screen6/2/202441Monitor Computers only use monitors to show you exciting operation results or marvelous and vivid pictures.Monitors also are the best windows for conversation between users and computers.6/2/202442Parameters of MonitorsElement Distance Video Bandwidth Solution Scan Style 6/2/202443Mouse The interface between a mouse and a system can take one of two forms:the mouse either generates a series of pulses when it is moved,or it increments and decrements counters.Most mice also include one or more buttons,and the system must be able to detect when a button is depressed.6/2/202444Optical Disks An optical disk is a disk on which data are encoded for retrieval by a laser.Optical disks offer information densities far beyond the range of current magnetic mass-storage devices.Currently,three versions of optical disk technology are competing for the mass-storage market,they are read-only optical disks,write-once optical disks,and erasable optical disks.6/2/202445Bus A bus is a shared communication link,which uses one set of wires to connect multiple subsystems.The two major advantages of the bus organization are versatility and low cost.A bus generally contains a set of control lines and a set of data lines.The control lines are used to signal requests and acknowledgments,and to indicate what type of information is on the data lines.The data lines of the bus carry information between the source and the destination.6/2/202446Key Wordsacknowledgement 承认，确认appropriately 适当地bandwidth 带宽blank 空白的cursor 光标documentation 文档，文件interface 接口，界面latency 潜伏，潜在layout 布局，分布marvelous 令人惊异的，了不起的minimize 最小化mouse 鼠标non-interlace 非隔行6/2/202447Key Wordsoptical 光学的parameter 参数periodically 定期地punctuation 标点符号responsive 响应，应答的reusability 可重复使用的solution 分辨率spacebar 空格键streamline 流线，流线型subsystem 子系统sustain 承受，支持typewriter 打字机video 视频6/2/202448Notes1 In interlace style,electron-beam sweeps elements in odd rows first time and does elements in even rows second time.本句中的electron-beam译作电子射枪，elements译作像素。译文：在隔行方式中，电子射枪首先扫描奇数项中的像素，第二次再扫描偶数项中的像素。6/2/202449Notes2 By monitoring the status of the button,the system can also differentiate between clicking the button and holding it down.本句中的“By monitoring the status of the button”是分词短语作状语。译文：依靠对按钮状态的监测，系统也就能区分单击按键与按着按键拖曳之间的差别。6/2/202450Notes3 Similarly,software interpretation of the mouse position means that the cursor doesnt jump completely off the screen when the mouse is moved a long distance in one direction.本句中，“when”引导时间状语从句。译文：同样，用软件描述鼠标位置，也意味着当鼠标沿一个方向长距离移动时，光标不会完全跳离出屏幕。6/2/202451Notes4 To write data,a powerful beam of laser light burns tiny spots or pits into the coating that covers the surface of these disks.本句中的“To write data”作目的状语，“that covers the surface of these disks”是定语从句，修饰“the coating”。译文：为了写入数据，激光的强大光束将覆盖在光盘的表层并烧结出小斑点或凹点。6/2/202452Notes5 One reason bus design is so difficult is that the maximum bus speed is largely limited by physical factors:the length of the bus and the number of devices.本句中的“bus design is so difficult”是定语，修饰“reason”，“that the maximum bus”是表语从句。译文：总线设计如此困难的一个原因是，总线的速度很大程度上受物理因素限制：总线长度和设备数量。6/2/202453Translation Exercises1.通信瓶颈 communication bottleneck2.总线协议 bus protocol3.像素距离 element distance4.只读光盘 read only optical disk5.电子枪 electron gun6.输出设备 output device7.水平方向 horizental direction8.总线带宽 bus bandwidth6/2/202454Translation Exercises1.numeric keypad 数字键盘2.electron-beam 电子束3.typematic effect 自动复击效应4.scan style 扫描类型5.data transfer rate 数据传输速率6.source and the destination 源和目的7.magnetic polarity 磁性8.disk sector 磁盘扇区6/2/202455Reading Material:How MP3 Files Work？The MP3 format is a compression system for music.The MP3 format helps reduce the number of bytes in a song without hurting the quality of the songs sound.The goal of the MP3 format is to