计算机基础全英文版的课件.ppt

Introduction to Computer Science”计算机文化基础USTB Computer Department“Introduction to Computer Science”•Class : Total 30 hours Lecture 16 hours, Lab 14 hours•Grading: Final exam 70% Others 30%•Website: –Username: S 学号–Password: 123456•Instructor : Taohong Zhang Contact: waterswordzth@Contents•Chapter 1: Computers and Digital Chapter 1: Computers and Digital BasicsBasics•Chapter 2: Computer HardwareChapter 2: Computer Hardware•Chapter 3: Computer SoftwareChapter 3: Computer Software•Chapter 4: OSChapter 4: OS•Chapter 5: NetworkChapter 5: Network•Chapter 6: CompressChapter 6: CompressChapter 1 Computers and digital basics When you have completed this chapter you should be able to:• Define the term “computer”, “microcomputer”– know the digital revolution– know the history of computer development– know the type of computer and function of computer– Differentiate between data and information, analog and digital–Describe how digital devices represent numbers, text, images, and soundmaster number and code. storage form of information • number system and conversion of number Section A all things digitalThe DIGITAL REVOLUTION•What is the digital revolution?What is the digital revolution?•The digital revolution is an ongoing process of social, The digital revolution is an ongoing process of social, political, and economic change brought by digital technology.political, and economic change brought by digital technology.•What technologies are fueling the digital revolution?What technologies are fueling the digital revolution?•Digital electronics, computers, communications, networks, Digital electronics, computers, communications, networks, the Web, and digitizationthe Web, and digitization•What caused the sudden upswing in computer ownership?What caused the sudden upswing in computer ownership?•The network and the WebThe network and the WebDigitizationDigitization is the process of converting text, numbers, sound, is the process of converting text, numbers, sound, photos and video into data that can be processed by digital devices.photos and video into data that can be processed by digital devices.•A computerA computer network network is a group of computers is a group of computers linked by wired or wireless technology to linked by wired or wireless technology to share data and resources.share data and resources.•The The InternetInternet is a global computer network is a global computer network•The The WebWeb (short for World Wide Web) is a (short for World Wide Web) is a collection of linked documents, graphics, and collection of linked documents, graphics, and sounds that can be accessed over the Internet.sounds that can be accessed over the Internet.Section A all things digitalConcepts:CONVERGENCE–What is convergence? (P.8 of E)–How does convergence affect the typical consumer?–QualitySection A all things digitalDIGITAL SOCIETYWhat is a computer? (Von Neumann’s definition)A computer is a multipurpose device that accepts input, process data, stores data, and produces output, all according to a series of stored instructions (P14.) •Adopt binary system•Store InformationSection B Digital DevicesA computer accepts input •“Input” :–The words and symbols in a document, –numbers for a calculation, –pictures, –temperatures from a thermostat, –audio signals from a microphone,– and instructions for completing a process;•An input device gathers and translates input into a form that the computer can process.–Keyboard is the main( standard ) input deviceSection B Digital DevicesA computer produce output •“output” : results produced by a computer–Reports–Documents–Graphs–Music •The main output device:–monitor–printerSection B Digital DevicesA computer processes data •data– refers to the symbols that represent facts, objects, and ideas•“process data” :–Performing calculations  –Modifying documents and pictures–Sorting lists of words or numbers  (p15 F.1-13)–Drawing graphs, •A computer processes data in a device called the central processing unit (CPU)Section B Digital DevicesA computer stores data •“Store data” : perform automatically–Memory - data waiting to be used–Storage - data left on a permanent basis while it is not needed for process•File - is a named collection of data that exists on a storage mediumSection B Digital Devices•computer program ---The series of instructions that tells computer how to carry out processing tasks.•Software-- programs•What kind of software do computer run?–System software  (P. 16)–Application software (P. 16)Section B Digital DevicesWhat’s so significant to store instructions  The Evolution of Computer History1.The First Generation- 1.The First Generation- Vacuum TubesVacuum Tubes (1946- (1946-1956)1956)（电子管（电子管））1946 ENIAC (Electronic numerical integrator and calculator) General-purpose electronic digital computer Wartime needs Decimal Programmed manually1952 EDVAC (The Von Neumann Machine) (Electronic discrete variable automatic computer) Stored-program concept Had general structure and function The Evolution of Computer •Weight:30t•Storage:80 byte•Speed:5000/s￿ ￿ 1950s  The birth of Computer Industry                 Commercial Computers   IBM：Series of 700/70002. The Second Generation: Transistors（（1957-1964）（晶体管））（晶体管）    1947 Bell Labs invented transistor    The late 1950s  NCR, RCA             Deliver the new technology IBM 7094 IBM 7094 Size of memory grew from 2K to 32K. Memory cycle time (the time to access one word of memory )fell from 30µs to 1.4 µs.Note: 1K = 210 =1024     The Evolution of Computer ￿ ￿3. The Third Generation: Integrated Circuits (1965-1971)4. 4. Later Generations    (1972-至今)   Large-scale integration (LSI): >1000 components   Very-large-scale integration (VLSI):>100,000 components    Microprocessors: ->microcomputer(pc)    All of the components of a CPU on a single chip the difference of computer and microcomputer: 1) microprocessor; 2) bus structure The Evolution of Computer 代次代次起止年份起止年份所用电子元所用电子元器件器件数据处理方数据处理方式式运算速度运算速度应用领域应用领域第一代第一代1946~1957电子管电子管汇汇 编编 语语 言言 、、代码程序代码程序几几 千千 ~几几万次万次/秒秒国国 防防 及及 高高科技科技第二代第二代1958~1964晶体管晶体管高高级级程程序序设设计语言计语言几几 万万 ~几几十万次十万次/秒秒工工程程设设计计、、数据处理数据处理第三代第三代1965~1970中中、、小小规规模模集成电路集成电路结结构构化化、、模模块块化化程程序序设设计计、、实实时时处处理理几几 十十 万万 ~几几百百万万次次/秒秒工工业业控控制制、、数据处理数据处理第四代第四代1970~今今大大规规模模、、超超大大规规模模集集成成电路电路分分时时、、实实时时数数 据据 处处 理理 、、计算机网络计算机网络几几 百百 万万 ~上上亿亿条条指指令令/秒秒工工 业业 、、 生生活活 等等 各各 方方面面计算机发展的四个阶段计算机发展的四个阶段Chinese “神威神威” computer•384 CPU384 CPU•384,000,000,000/s384,000,000,000/s•Memory size 48 GBMemory size 48 GB•Harddisk size 2.5TB Harddisk size 2.5TB The Functions of Computer Functions:Functions: Science computation Information disposal Process control Computer aided engineer (CAE) Artificial intelligence (AI)The Category of ComputerCategory (usage, cost, size, capability)Category (usage, cost, size, capability)commonly used computer categoriescommonly used computer categories1)Microcomputer (personal computer)2)servers3)Mainframes4) Supercomputers1.Personal computer•Microprocessor-based computing device for an individualWorkstation: Two meanings– 1. an ordinary personal computer connected to a network – 2. powerful desktop computers for high-performance tasks (such as CAD)Section B Digital Devices2. Server •Serve computers on a network supplying dataClient: requests data from a server is referred to as a client Section B Digital Devices3. Mainframe              Large, fast, expensive;Business, government;Provide centralized storage, processing and management for large amount of data;simultaneously handle thousands of users.Section B Digital Devices4. Supercomputer               ---- the fastest computers in the world Fastest, most expensive;Designed for “computer-intensive” task, such as molecular calculations, atmospheric modeling or simulating                     nuclear explosionsSection B Digital Devices计算机的分类数数 字字 计计 算算 机机模模 拟拟 计计 算算 机机数数模模混混合合计计算算机机按处理对象按处理对象按使用范围按使用范围通通 用用 计计 算算 机机专专 用用 计计 算算 机机按规模按规模… …巨巨 型型 计计 算算 机机大大/ /中型计算机中型计算机小小 型型 计计 算算 机机微微 型型 计计 算算 机机工工作作站站或或服服务务器器Data representation basic:•what is data?data refers to the symbols that represent people, events, things, and ideas. data can be a name, a number, the colors in a photo, or the note in a musical composition.•The difference of Data and informationdata is used by machine, such as computer;       information is used by humans.Section C. Digital Data RepresentationDigital Data Representation–Data representation•the form data is stored, processed, and transmitted–Analog and digital• the difference between analog and digital–Digital data is text, number that converted into discrete digits such as 0s and 1s.–Analog data is represented using an infinite scale of values.Section C Digital Data Representation1. Representing number–Numeric Data •Numbers used in arithmetic operations–Binary number system•0 and 1Section C Digital Data RepresentationüComputer store, process and transmit data with binary form    A computer uses a bit as the building block for more complex messages, which are constructed with a series of bits. • 1 bit can convey two units of information.Section C Digital Data Representation1. Representing numberunits of binary system   1 bit 1 byte = 8 bit 1 word = 2 byte 1kB (byte)  =  210 B 1MB (MegaByte)=  210 KB 1GB (GigaByte)=  210 MB 1TB (Tricro) =  210 GBNumber(数制数制)Some Notation:Some Notation:•Base/ radix （基数） •Digits （数字符号）•Weight （位权）Section C Digital Data RepresentationMultinomial unwrapped from the number according to the weight:1) The Decimal System：：(4723.75)10= 4×103＋＋7×102＋＋2×101＋＋3×100 ＋＋7×10-1＋＋5×10-22) The Binary System：： (11101. 01)2 =1×24＋＋1×23＋＋1×22＋＋0×21＋＋1×20 ＋＋0×2-1＋＋1×2-2Section C Digital Data Representation1. Representing number3) The hexadecimal system      Base, or radix of 16, digits (0,1,2,3,4,5,6,7,8,9, A, B, C, D, E, F)     S = { . . . s2 s1 s0.s-1 s-2 s-3 . ..}      S=Sn－116 n－1+Sn－216n－2+…+S116 1+S0160        +S－116－1+…+S－m16－m      F1.3=15*161+1*160+3*16-1Section C Digital Data Representation1. Representing number4) The octal system      Base, or radix of  8 , digits (0,1,2,3,4,5,6,7)       S = { . . . s2 s1 s0.s-1 s-2 s-3 . ..} S=Sn－18n－1+Sn－28n－2+…+S181+S080             +S－18－1+…+S－m8－m       23.3=2*81+7*80+3*8-183= ?Section C Digital Data Representation1) Conversion between Binary 1) Conversion between Binary and Decimaland Decimal To convert from decimal to binary, the integer and  fractional parts are handled separately.Number Conversiona) Convert decimal integer N into binary form: N =(1 ×2k) + (Rk × 2k-1) + .. . + (R3 × 22) + (R2 × 21) + (R1 ×20) Repeated divisionEx. Decimal 11 Quotient Remainder11/2 = 5 15/2 = 2 12/2 = 1 01/2 = 0 1Number Conversion1011(11)10= (1011)2 b) b) FractionalFractional part involved repeated part involved repeated multiplication.multiplication. F = (a-1× 1/2)+( a-2× 1/22)+( a-3× 1/23)+... This process is not necessarily exact. Ex. Decimal 0.81 Ex. Decimal 0.81 Product Integral Part    .1     1     0     0   1      10.81 × 2 = 1.6210.62 × 2 = 1.2410.24 × 2 = 0.4800.48 × 2 = 0.9600.96 × 2 = 1.9210.92 × 2 = 1.841  (0.81)10= (0.110011)2, (approximate) Ex. Decimal 0.25Ex. Decimal 0.25 Product Integral part 0.25×2 = 0.5 0 0.50×2 = 1.0 1 0.2510 = 0.01 (exact)0 1 2) Conversion between Hexadecimal and 2) Conversion between Hexadecimal and DecimalDecimalBase 16 (0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F)0000=0 1000=80001=1 1001=90010=2 1010=A0011=3 1011=B0100=4 1100=C0101=5 1101=D0110=6 1110=E0111=7 1111=FHexadecimal DecimalHexadecimal DecimalEx.1A16 = (116× 161)+( A16× 160) = (110× 161)+( 1010× 160) = 26 Binary Hexadecimal 1101 1110 0001 = DE116 D E 1 3) Conversion between Octal and Decimal3) Conversion between Octal and DecimalBase 8 (0,1,2,3,4,5,6,7)000=0 001=1 010=2 011=3 100=4 101=5 110=6 111=7 Octal DecimalOctal DecimalEx. 178 = (18× 81)+( 78× 80) = (8)+ (7) = 15 Binary OctalBinary Octal 101 111 001 = 5718 5 7 1整型数的存储•机器数：将一个数在机器中的存储形式（即编码）称为机器数。

•在计算机中带符号整数是采用补码表示的在计算机中带符号整数是采用补码表示的在计算机中带符号整数是采用补码表示的在计算机中带符号整数是采用补码表示的• 带符号数的最高位用来表示数的符号，一般用“0”表示“+”，用“1”表示“-”1 . 机器数与真值机器数与真值 # of Bits # of Bits ---------816 RangeRange-------------------------------------0                                         2550                                     65,535 整型数的原码、反码和补码整型数的原码、反码和补码正正正正数数数数：：原码、反码、补码相同原码、反码、补码相同原码、反码、补码相同原码、反码、补码相同 符号位为符号位为符号位为符号位为0 0，数值为对应的二进制数数值为对应的二进制数数值为对应的二进制数数值为对应的二进制数例如：＋例如：＋例如：＋例如：＋109 109 [ [＋＋＋＋109]109]原原原原 = [= [＋＋＋＋109]109]反反反反 = [= [＋＋＋＋109109] ]补补补补= = 0 011011011101101•原码：原码：原码：原码：符号位为符号位为符号位为符号位为1 1 1 1，数值为绝对值的二进制数。

数值为绝对值的二进制数数值为绝对值的二进制数数值为绝对值的二进制数 例：例：例：例：[-109][-109][-109][-109]原原原原= = = =1 1 1 11101101110110111011011101101•反码：反码：反码：反码：将原码除符号位外，逐位取反将原码除符号位外，逐位取反将原码除符号位外，逐位取反将原码除符号位外，逐位取反 例：例：例：例：[-109][-109][-109][-109]反反反反= = = = 1 1 1 10010010001001000100100010010•补码：补码：补码：补码：将反码末位加将反码末位加将反码末位加将反码末位加1 1 1 1 例：例：例：例：[-109][-109][-109][-109]补补补补= = = =1 1 1 10010011001001100100110010011 负数负数：： Arithmetic and Logic Rule ArithArithmeticmetic加加 0+0=0 1+0=0+1=1 1+1=0+0=0 1+0=0+1=1 1+1=1010减减 0-0=0 1-0=1 1-1=0 0-1=0-0=0 1-0=1 1-1=0 0-1=1 1乘乘 0*0=0 0*1=1*0=0 1*1=10*0=0 0*1=1*0=0 1*1=1除除 0/1=0 1/1=10/1=0 1/1=1LogicLogic与与 0∧0=0 0∧1=0 1∧0=0 1∧1=10∧0=0 0∧1=0 1∧0=0 1∧1=1或或 0∨0=0 0∨1=1 1∨0=1 1∨1=10∨0=0 0∨1=1 1∨0=1 1∨1=1非非 非非0 0为为1 1 非非1 1为为0 0Example of Arithmetic and Logic •ex3ex3：：a = 1100a = 1100，，b = 0110b = 0110 a∨ba∨b、、a∧ba∧b、、ˉˉa a 1100 1100 1100 ∨ 0110 ∨ 0110 ∧ 0110 ∧ 0110 逻辑非为：逻辑非为： 1110 0100 00111110 0100 0011•ex1ex1：： 101. 01101. 01 +110. 01+110. 01 1011. 10 1011. 10ex2ex2：： 101. 111101. 111 + 11. 011 + 11. 011 1001. 010 1001. 010 2. Representing symbolsüHow to denote character?       a) ASCII coding  （（ American Standard Code American Standard Code for Information Interchangefor Information Interchange））uses 7 bits to represent 27 Symbols (128 symbols), including uppercase and lowercase letters, special control codes, numerals, and punctuation symbols. Section C Digital Data RepresentationASCII Rule•One byte (8 bits binary codeOne byte (8 bits binary code) ) represents one characterrepresents one character0 0The top of byte is “0”The others(7 bits) can have 128 binary codes. Ex ：：0000 0000-0111 1111Represent 128 characters.Section C Digital Data Representation ASCII RuleA为（为（0100 0001））2 = 65记住：记住：0字符的字符的ASCII码是码是48A字符的字符的ASCII码是码是65a字符的字符的ASCII码是码是97a与与A 的的ASCII码之差是码之差是32b) Chinese code: GB-2312•《《信息交换用汉字编码字符集信息交换用汉字编码字符集——基本集基本集》》/ / GB2312-80GB2312-80 •74457445 Chinese and graph symbolChinese and graph symbol：： commoncommon：：202202；； sequencesequence：：6060；； numbernumber：：2222；； EnglishEnglish：：5252；；JapanJapan：：169169；； GreekGreek：：4848; ; RussiaRussia：：6666 ChineseChinese：：67636763；；( (37553755；；30083008) )•Two bytesTwo bytes represent each Chinese or symbol. represent each Chinese or symbol.Section C Digital Data Representation高高八八位位低八位低八位例如：例如：“啊啊” 的的国标国标码为码为( (3021)3021)1616 “住住” …… ( (5721)5721)1616 汉字的编码各种代码之间的关系：各种代码之间的关系：汉字输入汉字输入输入码输入码（外码）（外码）国标码国标码机机内内码码输出码输出码（字形码）（字形码）汉字输出汉字输出高位置高位置“1”•包括：信息交换码（国标码）、机内码、输入码和输包括：信息交换码（国标码）、机内码、输入码和输出码出码•机内码（亦称内码）：汉字（符号）在计算机内部的二进制代码。

 输入码（外码）•输入码：汉字输入时使用的编码例如：例如：例如：例如： “ “国国国国” ” 的输入码的输入码的输入码的输入码全拼：全拼：全拼：全拼：guoguoguoguo；五笔字形码：；五笔字形码：；五笔字形码：；五笔字形码：lgylgylgylgy；区位码：；区位码：；区位码：；区位码：2590259025902590典型的输入码有：全拼、五笔字形、微软输入法、典型的输入码有：全拼、五笔字形、微软输入法、典型的输入码有：全拼、五笔字形、微软输入法、典型的输入码有：全拼、五笔字形、微软输入法、智能智能智能智能ABCABCABCABC输入法、搜狗拼音输入法、区位码等输入法、搜狗拼音输入法、区位码等输入法、搜狗拼音输入法、区位码等输入法、搜狗拼音输入法、区位码等 输出码（字模、字型码）输出码：汉字输出时使用的编码输出码：汉字输出时使用的编码输出码：汉字输出时使用的编码输出码：汉字输出时使用的编码l l以点阵形式表示以点阵形式表示以点阵形式表示以点阵形式表示如如如如16×1616×1616×1616×16点阵、点阵、点阵、点阵、24×2424×2424×2424×24点阵、点阵、点阵、点阵、32×3232×3232×3232×32点阵等点阵等点阵等点阵等l l一个一个一个一个16×1616×1616×1616×16点阵汉字输出码所占存储空间：点阵汉字输出码所占存储空间：点阵汉字输出码所占存储空间：点阵汉字输出码所占存储空间： 16/8×16=3216/8×16=3216/8×16=3216/8×16=32个字节个字节个字节个字节16x16点阵汉字及编码24x24点阵汉字32x32点阵汉字Difference:1. Image quality;2. The amount required to store the image;3. The amount of time required to transmit the image4. How easy to modify the image and so on3. Representing ImagesSection C Digital Data Representation Bitmap graphic method of a black-and-white image – monochrome graphic1 pixel can be represented by 1 bit.Grayscale graphicsGrayscale graphic: display a bitmap image using shades of gray or “gray classes” (black and white photos)256-grayscale graphic u1 pixel can be represented by 8 bits.uA full screen 256-grayscale graphic at 640 * 480 resolution requires 307,200 bytes. Color graphics Color graphic: display a bitmap image using coloru 16 color : 1 pixel can have 16 color, need 4 bits u256 color:1 pixel can have 256 color, need 8 bits u16.7 million colors (24-bit or true-color graphic) color: need 3 bytes to present : Red Green Bluewidth：：271height：：300color：：2size：：9.9 KBwidth：：271height：：300color：：4size：：19.8 KBExample of graphSection C Digital Data Representationwidth：：271height：：300color：：256size：：79.4 KBwidth：：271height：：300color：：true colorsize：：238.2 KBExample of graphSection C Digital Data RepresentationComputation for storage•To store a true color image To store a true color image –resolution 352×288–Color byte 3B–storage= 352×288 ×3=297KB•If enhance image resolutionIf enhance image resolution–storage= 768×1024 ×3=2.25MBDecrease the graphic storage and transmission timeApproximator: Making an image physically smaller by shrinking it or cropping it will decrease the number of pixels required to represent the graphic. Compression: Size of graphic file can be reduced by technique known as compressionDithering: reduce the number of colors in a graphic.Vector graphic and Digital VideoVector graphicDifference between vector graphic and bitmap graphic?vector graphic: consist of a set of instructions that recreates a picture.You can use vector graphics software to draw a picture,  CIRCLE 40 Y200 150 means: create a circle with 40 pixels radius, color it yellow, and place the center of the circle 200 pixels from the left of the screen and 150 pixels from the top of the screenDigital videoComposed of a series of frames. Each frame is a still picture. A video display 30 frames per second.Waveform audio: a digital representation of sound.To record sound, samples of the sound are collected at periodic intervals and stored as numeric data.Sampling rate : the number of times per second that the sound is measured during the recording process. Expressed in hertz(Hz)4. Representing Audio Example of Audio encode 采样点采样点t1t1t2t2t3t3t4t4t5t5t6t6t7t7... ... 幅值幅值00110011010101010111011110011001101110111101110111101110......Analog signals technique parameterSampling rate Sampling rate ( Hz ex:( Hz ex:11.02511.025kHz/kHz/22.0522.05kHz)kHz)Sampling precision Sampling precision (bit(bit ex:8 bits/16 bitsex:8 bits/16 bits) )Track number Track number (single(single、、doubledouble) )采样频率采样频率11KHz 8位量化位量化 采样频率采样频率22KHz 16位量化位量化Circuits and chips•WhatWhat’s a computer chip?s a computer chip?the terms computer chip, microchip, and the terms computer chip, microchip, and chip originated as technical jargon for chip originated as technical jargon for integrated circuit.integrated circuit.Section C Digital Data Representation– integrated circuit is an super-thin slice of semiconducting material packed with microscopic circuit elements, such as wires, transistors, capacitors, logic gates, and resistors.(p27 f1-30)Section D. Digital processingPrograms and instruction sets:•How do digital devices process data?–The data is manipulated under the control of a computer program.–The human-readable version of a program is called source code.How does source code get converted?The procedure for translating source code into 0s and 1s can be accomplished by a compiler or an interpreter.–A compiler converts all the statements in a program in a single batch, and the resulting collection of instructions, called object code, is placed in a new file.(p30 f1-34)Digital processingSection D Digital Processing•“语言语言”是人机交流的工具是人机交流的工具•程序是用程序是用“语言语言”写成的计算机可以识别的写成的计算机可以识别的“文章文章”•用于编写计算机可以执行的程序的语言称为程序设计语用于编写计算机可以执行的程序的语言称为程序设计语言言机器语言机器语言机器指令机器指令0 0 或或 1 1 代码代码 与语言习惯差别很大难以学与语言习惯差别很大难以学习和记忆依赖机器的类型习和记忆依赖机器的类型汇编语言汇编语言用助记符代替机器代用助记符代替机器代码；用变量代替各类码；用变量代替各类地址地址克服记忆的难点其他与假期克服记忆的难点其他与假期语言类似语言类似高级语言高级语言类似数学语言、接近自然语言、具有通用性和可移植类似数学语言、接近自然语言、具有通用性和可移植性、不依赖具体的计算机类型性、不依赖具体的计算机类型高级程序的编译运行方式高级程序的编译运行方式可执行程序可执行程序编译程序编译程序高级语言程序高级语言程序目标程序目标程序连接程序连接程序编译编译连接连接Compiler–An interpreter converts and executes one statement at a time while the program is running.执行执行解释程序解释程序高级语言程序高级语言程序解释解释Interpreter高级程序的解释运行方式高级程序的解释运行方式•What does the conversion process What does the conversion process produce?produce?–Instruction set: collection of preprogrammed activitiesis designed to be general purpose so that programmers can use it in creative ways for the wide variety of tasks performed by all kinds of digital devices.–Instruction: each instruction has a corresponding sequence of 0s and 1s. E.g add----00000100–Machine language: can be directly executed by the processor’s circuitryDigital processing•A machine code instruction has two A machine code instruction has two parts: parts: the op codethe op code and and the operandthe operand. .•Eg: instruction: add 1Eg: instruction: add 1 00000100 00000001Digital processingOp codeOperand•P31 f1-36Components: Program ControlCentral Processing UnitArithmetic –LogicUnit (ALU)Main memory I/OEquip-mentregisterProcessor logicProcessor logic•What happens when a computer executes an What happens when a computer executes an instruction?(p32 f1-38)instruction?(p32 f1-38)1.Fetch instruction4. Increment pointer to the next instruction3. Execute instruction2. Interpret instruction•What role does the control unit play?What role does the control unit play?(p32 f1-39)(p32 f1-39)Processor logic•What does the ALU swing into action?What does the ALU swing into action?(p32 f1-40)(p32 f1-40)。