计算机专业英语Unit-2-Hardware课件.ppt

1、HardwarePassage One A Brief Introduction to the ComputerTraining target:In this part,our target is to train your reading comprehension.We have made the flexible sentences strong black and marked the subject,predicate and have object of them.Try to grasp the main idea of these sentences.主语、谓语、宾语Passa

2、ge One A Brief Introduction to the ComputerA computer is just a machine,but a computer system consists of two main elements:the machine and programs.Like a person,a computer system is composed of two parts:the bonehardware and the soulsoftware.The central idea of a computing system is that input is

3、processed into output.Input is the data which is entered into the computer,and output is the result of processing done by the computer,usually printed out or displayed on the screen.Let us get closer to the computer from the basic components.When talking about computers,such image as Pic 2.1 will ap

4、pear in our mind:a display screen known as the basic output device,a keyboard usually together with a mouse as the basic input device,and a cabinet known as a machine box.program n.程序hardware n.硬件software n.软件component n.部件display screen 显示器output device 输出设备keyboard n.键盘mouse n.鼠标input device 输入设备c

5、abinet n.匣子,机壳Passage One A Brief Introduction to the ComputerPassage One A Brief Introduction to the ComputerWith the development of science and technology,the modern computer becomes more and more flexible,and the hardware family becomes stronger and stronger.A lot of new peripherals appear.These

6、peripherals can be classified into two groupsinput devices and output devices.Input devices(Pic 2.2),as the name suggests,are any hardware components that allow you to put the data,programs and commands into the computer.One of the most important input devices is the keyboard.Users can type in text

7、or enter keyboard commands using the keyboard.Another device which can be used to input data is a scanner.This electronic device is used to transfer an image such as text,or pictures into the computer.The most useful pointing device is a mouse,which allows the user to point to elements on the screen

8、.And there are some other input devices,such as microphone,PC camera,digital camera,joystick,graphics tablet and light pen.flexible adj.灵活的peripheral n.外围设备scanner n.扫描机pointing device 定点设备microphone n.麦克风PC camera 摄像头digital camera 数码相机joystick n.游戏杆graphics tablet 图形写字板light pen 光笔Passage One A Br

9、ief Introduction to the ComputerPassage One A Brief Introduction to the ComputerOutput devices(Pic 2.3)are devices that let you see what the computer has accomplished.Several devices are used to display the output from a computer.The favorite monitor is the LCD,which is slim and takes up little spac

10、e,and displays text and images with greater clarity.Another important output device is the printer,which allows the user to copy the data in the computer into the paper.Speakers and headphones allow the listener to hear audio data,such as speech or music through the computer.And there are some other

11、 output devices,such as projector and facsimile machine.LCD(Liquid Crystal Display)abbr.液晶显示器 speaker n.扬声器headphone n.耳机audio n.音频projector n.投影仪facsimile machine 传真机Passage One A Brief Introduction to the ComputerPassage One A Brief Introduction to the ComputerAll the components of a computer that

12、 we can see and feel are hardware.They work together to help us with our daily work.Then what is software?Software,also called a computer program,is a set of commands which the computer understands and follows,and a set of instructions that tell the hardware of a computer what to do.These commands a

13、nd instructions perform tasks which the user wants the computer to do.Do you know how a computer can manage so many devices?The real secret lies in the machine box.When we take the cover off a small computer and look inside,the real computer appears in front of us,we will see a few circuit boards,so

14、me wires and some cables.In fact,the motherboard is the most important part in the machine box.Two main components on the motherboard are the CPU and mand n.命令instruction n.指令wire n.导线cable n.电缆线motherboard n.母板，主板CPU(Central Processing Unit)abbr.中央处理器memory n.内存Passage One A Brief Introduction to t

15、he ComputerThe CPU is sometimes referred to as the processor.It is the electronic device that interprets and carries out the basic instructions that operate the computer.The CPU is the control and data processing center of the whole computer system.You can simply regard it as a skillful cook,the onl

16、y difference is just that the cook processes meat and vegetable,and makes them become delicious dishes.Here meat and vegetables are the input for the cook,and some dishes certainly are the output from the cook.Now turn back to our CPU,it can process the digital data from an input device,and output t

17、hem to an output devices.Just like the excellent cook we mentioned before,he must need a number of empty plates around him,which stored meats and vegetables processed by the cook,thats a great help for his cooking.And after dinner,the plates should be cleaned up.Memory stores information processed b

18、y the CPU.The data stream can flow from the CPU into memory or on the contrary.Memory consists of RAM and ROM.Any information in RAM will be lost when the computer is turned off,just like that the plates be cleaned by the cook.cook n.厨师digital data 数字数据data stream 数据流RAM(Random Access Memory)abbr.随机

19、存取存储器contrary n.相反ROM(Read Only Memory)abbr.只读存储器Passage One A Brief Introduction to the ComputerMost of the devices connected to the computer communicate with CPU in order to carry out a task.The CPU controls the data flow on the inner Bus,there are three kinds of Buses used in our computer:AB,DB a

20、nd CB.The most popular bus to be used on a motherboard is a PCI bus.That is peripheral components interface bus.The CPU uses storage to hold data,instructions and information for future use.Storage also called secondary storage,auxiliary storage,Think of storage as a little cabinet used to hold file

21、 folders,and memory as the top of your desk.When you need a file,you can get it from the filing cabinet(storage)and place it on your desk(memory).When you finish a file,you return it to the filing cabinet(storage).The items in storage are retained even when power is removed from the computer.inner B

22、us 内部总线AB(Address Bus)abbr.地址总线DB(Data Bus)abbr.数据总线CB(Control Bus)abbr.控制总线PCI(Peripheral Component Interconnect)abbr.外设部件互连auxiliary storage辅助存储器file folder 文件夹filing cabinet 文件柜retain v.保留Passage One A Brief Introduction to the Computerhardware n.硬件 software n.软件keyboard n.键盘 mouse n.鼠标printer n.

23、打印机 scanner n.扫描机speaker n.音箱 projector n.投影仪wire n.导线 cable n.电缆线motherboard n.母板，主板 memory n.内存instruction n.指令 headphone n.耳机speaker n.扬声器 audio n.音频scanner n.扫描机 joystick n.游戏杆microphone n.麦克风 peripheral n.外围设备output device 输出设备 input device 输入设备 Key WordsPassage One A Brief Introduction to the

24、Computerdisplay screen 显示器 light pen 光笔auxiliary storage 辅助存储器 inner Bus 内部总线file folder 文件夹 facsimile machine 传真机digital data 数字数据 data stream 数据流pointing device 定点设备 PC camera 摄像头 digital camera 数码相机 command n.命令graphics tablet 图形写字板 CPU（Central Processing Unit）abbr.中央处理器RAM（Random Access Memory）a

25、bbr.随机存取存储器ROM（Read Only Memory）abbr.只读存储器LCD（Liquid Crystal Display）abbr.液晶显示器 PCI（Peripheral Component Interconnect）abbr.外设部件互连AB（Address Bus）abbr.地址总线DB（Data Bus）abbr.数据总线CB（Control）Bus abbr.控制总线Key WordsPassage Two How Does a Computer Work?Training target:In this part our target is to train your

26、 reading speed.You should pay more attention to“keywords”.We have marked keywords in some paragraphs.You can quickly grasp the main idea of the sentences and paragraphs by these keywords,the rest can be practiced by yourself.It will raise your reading speed.关键词Passage Two How Does a Computer Work?Wh

27、en we talk about the computer,we usually meet the topic:motherboard(Pic 2.4).The main circuit board in a computer is called the motherboard.It is a flat board that holds all of the key elements microprocessorn.微处理器socket n.插座plug in 插上that make up the“brain”of the system,including the microprocessor

28、 or CPU,RAM or primary memory,and expansion slots which are sockets where other circuit boards called expansion boards may be plugged in.Passage Two How Does a Computer Work?Let us use the system shown in Pic 2.5 to show you how a typical computer works.A computer is controlled by a stored program,s

29、o if we want to use a computer,the first step is copying the program from diskette into memory.Now the processor can begin executing instructions;the data input from the keyboard are stored in memory.The processor processes the data and then stores the results back into memory.At last,we can get the

30、 result.processor n.处理器executev.执行Passage Two How Does a Computer Work?Now we can see that a computer system consists of four basic components.An input device provides data.The data are stored in memory,which also holds a program.Under the controls of the program,the computers processor processes th

31、e data.The results flow from the computer to an output device.Let us introduce the system components one by one,beginning with the processor.The processor,usually called the central processing unit(CPU)or main processor,is the heart of a computer.It is the CPU that in fact processes or manipulates d

32、ata and controls all the rest parts of the computer.How can it manage its job?The secret is software.Without a program to provide control,a CPU can do nothing.How can a program guide the CPU through the processes?Let us consider from the basic element of a programinstruction.consists of 由组成manipulat

33、e v.处理，操作element n.元素Passage Two How Does a Computer Work?An instruction is composed of two parts:an operation code and one or more operands(Pic 2.6).The operation codes tell the CPU what to do and the operands tell the CPU where to find the data to be manipulated.operand n.操作数operation code 操作码Pass

34、age Two How Does a Computer Work?The processor contains four major components(Pic 2.7):a clock,an instruction control,an arithmetic and logic unit(usually shortened ALU)and several registers.The clock generates precisely timed pulses of current that synchronize the processors other components.Then t

35、he instruction control unit determines the location of the next instruction to be executed and fetches it from the main memory.The arithmetic and logic unit performs arithmetic operations(such as addition and subtraction)and logic operations(such as testing a value to see if it is true or false),whi

36、le the registers are temporary storage devices that hold control information,key data and some intermediate results.Since the registers are located in the CPU,the processing speed is faster than the main memory.Then which is the key component to a computers speed?It is the clock!In more detail,it is

37、 the clocks frequency that decides a computers processing speed.When we buy a computer,we usually consider the main frequency first,and that means a clocks frequency.precisely adv.精确地pulse n.脉冲current n.电流synchronize v.同步register n.寄存器temporary adj.暂时的intermediate adj.中间的frequency n.频率Passage Two Ho

38、w Does a Computer Work?Now we will talk more in detail about the Microprocessors and Central Processing Units(Pic 2.8).Microprocessors are central processing units etched on a tiny chip of silicon and,thus,are called microchips.Microprocessors contain many electronic switches,called transistors,whic

39、h determine whether electric current is allowed to pass through or now.Transistors are the basic switch n.开关Passage Two How Does a Computer Work?building blocks of microprocessors.A single microchip may contain millions of transistors.When electric current is allowed to pass through,the switch is on

40、.This represents a 1 bit.If the current does not pass through,the switch is off.This represents a 0 bit.Different combinations of transistors represent different combinations of bits,which are used to represent special characters,letters,and digits.represent v.代表combination n.组合Passage Two How Does

41、a Computer Work?microprocessor n.微处理器processor n.处理器operand n.操作数 register n.寄存器frequency n.频率 switch n.开关socket n.插座 pulse n.脉冲synchronize v.同步 processor n.处理器plug in 插上 operation code 操作码Key WordsReading Storage DevicesTraining target:Read the following reading materials and use the reading skills

42、 mentioned in the passage above.There may be some new words in the reading materials,just try to guess the meaning and put your dictionary aside.Reading Storage DevicesWe have known that the CPU controlled by program can process data.Then where are the data and the program from?The answer is storage

43、 devices.We usually divide the storage devices into two types:the main memory and the secondary storage.A CPU can only execute the instructions of a program which has already been in the main memory.The main memory of most computers is composed of RAM.A programmer can read and write RAM.We can store

44、 data and programs into RAM.When we have finished using them,we can let new ones occupy the position of the main memory,destroying the old ones.In a word,the content of RAM is easy to change.Sometimes we dont want the content of memory to be changed,for example,the automatic teller terminals used in

45、 many banks.They are controlled by a small computer,which is controlled by a program.If someone can the data to give free access to certain accounts,the bank would not Reading Storage Devicesallow such things to happen.In fact,these programs are stored in ROM,which we can only read but cannot modify

46、.In a word,ROM is permanent memory that can be read,but not be written.How can a program or data enter the computer system?We often use diskette drive to copy them into the main memory.Then we come to the concept of secondary storage.Hard Disk The hard drive is also called the hard disk,hard disk dr

47、ive or fixed disk drive.The hard drive(Pic2.9)is the primary device that a computer uses to store data.Most computers have one hard drive located inside the computer case.If a computer has one hard drive,it is called“drive C”.If a computer has additional hard drives,it is called“drive D,E,F”,and so

48、on.And the hard drive light is on when the computer is using the hard drive.Do not move the computer when this light is on.Reading Storage DevicesThe hard drive magnetically stores data on the stack of rotating disks,called platters.And a hard drive has several read/write heads that read and record

49、data on the disks.A hard drive can store your programs and data files.How shall we choose a hard drive?The first factor is the capacity.The amount of information a hard drive can store is measured in bytes.A hard drive with a capacity of 2GB to 20GB will suit most home and business users.Purchase th

50、e largest hard drive you can afford.A hard drive will be quickly filled up with new programs and data.For example,Microsoft Word is a word processing program that requires about 16 MB of hard drive space.The second factor is average access time.The average access time is the speed at which a hard dr