计算机基础,全英文版的课件

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,“,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:,Contents,Chapter 1: Computers and Digital Basics,Chapter 2: Computer Hardware,Chapter 3: Computer Software,Chapter 4: OS,Chapter 5: Network,Chapter 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 sound,master number and code,.,storage form of information,number system and conversion of number,Section A all things digital,The DIGITAL REVOLUTION,What is the digital revolution?,The digital revolution is an ongoing process of social, political, and economic change brought by digital technology.,What technologies are fueling the digital revolution?,Digital electronics, computers, communications, networks, the Web, and digitization,What caused the sudden upswing in computer ownership?,The network and the Web,Digitization,is the process of converting text, numbers, sound, photos and video into data that can be processed by digital devices.,A computer,network,is a group of computers linked by wired or wireless technology to share data and resources.,The,Internet,is a global computer network,The,Web,(short for World Wide Web) is a collection of linked documents, graphics, and sounds that can be accessed over the Internet.,Section A all things digital,Concepts:,CONVERGENCE,What is convergence? (P.8 of E),How does convergence affect the typical consumer?,Quality,Section A all things digital,DIGITAL SOCIETY,What is a computer? (,Von Neumanns 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 Information,Section 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 device,Section B Digital Devices,A computer produce,output,“output” : results produced by a computer,Reports,Documents,Graphs,Music,The main output device:,monitor,printer,Section 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 medium,Section 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 Devices,Whats so significant to store instructions,The Evolution of Computer,History,1.The First Generation-,Vacuum Tubes,(1946-1956),（电子管,）,1946,ENIAC,(Electronic numerical integrator and calculator),General-purpose electronic digital computer,Wartime needs,Decimal,Programmed manually,1952,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,1950,s The birth of Computer Industry,Commercial Computers,IBM,：,Series of 700/7000,2. The Second Generation:,Transistors,（,1957-1964,）（晶体管）,1947 Bell Labs invented transistor,The late 1950s NCR, RCA,Deliver the new technology,IBM 7094,Size of memory grew from 2K to 32K.,Memory cycle time (the time to access one word of memory )fell from 30,s to 1.4,s.,Note: 1K =,2,10,=1024,The Evolution of Computer,3. The Third Generation: Integrated Circuits,(1965-1971),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,起止年份,所用电子元器件,数据处理方式,运算速度,应用领域,第一代,19461957,电子管,汇编语言、代码程序,几千,几万次,/,秒,国防及高科技,第二代,19581964,晶体管,高级程序设计语言,几万,几十万次,/,秒,工程设计、数据处理,第三代,19651970,中、小规模集成电路,结构化、模块化程序设计、实时处理,几十万,几百万次,/,秒,工业控制、数据处理,第四代,1970,今,大规模、超大规模集成电路,分时、实时数据处理、计算机网络,几百万,上亿条指令,/,秒,工业、生活等各方面,计算机发展的四个阶段,Chinese “,神威,” computer,384 CPU,384,000,000,000/s,Memory size 48 GB,Harddisk size 2.5TB,The Functions of Computer,Functions:,Science computation,Information disposal,Process control,Computer aided engineer (CAE),Artificial intelligence (AI),The Category of Computer,Category (usage, cost, size, capability),commonly used computer categories,Microcomputer (personal computer),servers,Mainframes,Supercomputers,Personal computer,Microprocessor-based computing device for an individual,Workstation:,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 data,Client:,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 explosions,Section B Digital Devices,计算机的分类,数字计算机,模拟计算机,数模混合计算机,按处理对象,按使用范围,通用计算机,专用计算机,按规模, ,巨型计算机,大,/,中型计算机,小型计算机,微型计算机,工作站或服务器,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 information,data 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 1,Section C Digital Data Representation,Computer 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 Representation,1. Representing number,units of binary system,1 bit,1 byte = 8 bit,1 word = 2 byte,1kB (byte) = 2,10,B,1MB (MegaByte)= 2,10,KB,1GB (GigaByte)= 2,10,MB,1TB (Tricro) = 2,10,GB,Number(,数制,),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,= 410,3,710,2,210,1,310,0,710,-1,510,-2,2) The Binary System,：,(11101. 01),2,=12,4,12,3,12,2,02,1,12,0,02,-1,12,-2,Section C Digital Data Representation,1. Representing number,3) 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 = . . . s,2,s,1,s,0,.s,-1,s,-2,s,-3,. .,S=,S,n,1,16,n,1,+S,n,2,16,n,2,+S,1,16,1,+S,0,16,0,+S,1,16,1,+S,m,16,m,F1.3=15*16,1,+1*16,0,+3*16,-1,Section C Digital Data Representation,1. Representing number,4) The octal system,Base, or radix of 8 , digits (0,1,2,3,4,5,6,7),S = . . . s,2,s,1,s,0,.s,-1,s,-2,s,-3,. .,S=,S,n,1,8,n,1,+S,n,2,8,n,2,+S,1,8,1,+S,0,8,0,+S,1,8,1,+S,m,8,m,23.3=2*8,1,+7*8,0,+3*8,-1,83= ?,Section C Digital Data Representation,1) Conversion between Binary and 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 2,k,) + (R,k, 2,k-1,) + . . + (R,3, 2,2,) + (R,2, 2,1,) + (R,1,2,0,),Repeated,division,Ex. Decimal 11,Quotient Remainder,11/2 = 5 1,5/2 = 2 1,2/2 = 1 0,1/2 = 0 1,Number Conversion,1,0,1,1,(11),10,= (1011),2,b),Fractional,part involved repeated,multiplication.,F = (a,-1, 1/2)+( a,-2, 1/2,2,)+( a,-3, 1/2,3,)+.,This process is not necessarily exact.,Product Integral Part .1 1 0 0 1 1,0.81 2 = 1.621,0.62 2 = 1.241,0.24 2 = 0.480,0.48 2 = 0.960,0.96 2 = 1.921,0.92 2 = 1.841,(),10,=,(),2, (approximate),Product Integral part,2 = 0.5 0,0.502 = 1.0 1,10,= 0.01 (exact),0 1,2) Conversion between Hexadecimal and Decimal,Base 16 (0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F),0000=0 1000=8,0001=1 1001=9,0010=2 1010=A,0011=3 1011=B,0100=4 1100=C,0101=5 1101=D,0110=6 1110=E,0111=7 1111=F,Hexadecimal Decimal,16,= (1,16, 16,1,)+( A,16, 16,0,) = (1,10, 16,1,)+( 10,10, 16,0,) = 26,Binary Hexadecimal,1101 1110 0001 = DE1,16,D E 1,3) Conversion between Octal and Decimal,Base 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 Decimal,Ex. 17,8,= (1,8, 8,1,)+( 7,8, 8,0,) = (8)+ (7) = 15,Binary Octal,101 111 001 = 571,8,5 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,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,# of Bits,-,8,16,Range,-,0 255,0 65,535,整型数的原码、反码和补码,正,数,：,原码、反码、补码相同。,符号位为,0,，数值为对应的二进制数。,例如：,109,109,原,= ,109,反,= ,109,补,=,0,1101101,原码：,符号位为,1,，数值为绝对值的二进制数。,例：,-109,原,=,1,1101101,反码：,将原码除符号位外，逐位取反。,例：,-109,反,=,1,0010010,补码：,将反码末位加,1,。,例：,-109,补,=,1,0010011,负数,：,Arithmetic and Logic Rule,Arithmetic,加,0+0=0 1+0=0+1=1 1+1=,10,减,0-0=0 1-0=1 1-1=0 0-1=,1,乘,0*0=0 0*1=1*0=0 1*1=1,除,0/1=0 1/1=1,Logic,与,00=0 01=0 10=0 11=1,或,00=0 01=1 10=1 11=1,非,非,0,为,1,非,1,为,0,Example of Arithmetic and Logic,ex3,：,a = 1100,，,b = 0110,ab,、,ab,、,a,1100 1100 1100, 0110, 0110,逻辑非为：,1110 0100 0011,ex1,：,101. 01,+110. 01,1011. 10,ex2,：,101. 111,+ 11. 011,1001. 010,2.,Representing symbols,How to denote character?,a) ASCII coding,（,American Standard Code for Information Interchange,）,uses 7 bits to represent 2,7,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 code,),represents one character,0,The top of byte is “0”,The others(7 bits) can have,128,binary codes. Ex,：0000 0000-0111 1111,Represent 128 characters.,Section C Digital Data Representation,ASCII Rule,A,为（,0100 0001,）,2,= 65,记住：,0,字符的,ASCII,码是,48,A,字符的,ASCII,码是,65,a,字符的,ASCII,码是,97,a,与,A,的,ASCII,码之差是,32,b) Chinese code: GB-2312,信息交换用汉字编码字符集,基本集,/,GB2312-80,7445,Chinese and graph symbol,：,common,：,202,；,sequence,：,60,；,number,：,22,；,English,：,52,；,Japan,：,169,；,Greek,：,48,;,Russia,：,66,Chinese,：,6763,；,(,3755,；,3008,),Two bytes,represent each Chinese or symbol.,Section C Digital Data Representation,高八位,低八位,例如：,“,啊,”,的,国标,码为,(,3021),16,“,住,”,(,5721),16,汉字的编码,各种代码之间的关系：,汉字输入,输入码（外码）,国标码,机内码,输出码（字形码）,汉字输出,高位置“,1”,包括：信息交换码（国标码）、机内码、输入码和输出码,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：,“,国,”,的输入码,全拼：,guo,；五笔字形码：,lgy,；区位码：,2590,典型的输入码有：全拼、五笔字形、微软输入法、智能,ABC,输入法、搜狗拼音输入法、区位码等。,输入码不唯一！,输出码（字模、字型码）,输出码：汉字输出时使用的编码。,以点阵形式表示。,如,1616,点阵、,2424,点阵、,3232,点阵等,一个,1616,点阵汉字输出码所占存储空间：,16/816=32,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 on,3.,Representing,Images,Section C Digital Data Representation,Bitmap graphic method of a,black-and-white image, monochrome graphic,1 pixel can be represented by 1 bit.,Grayscale graphics,Grayscale graphic:,display a bitmap image using shades of gray or,“,gray classes,”,(black and white photos)256-grayscale graphic,1 pixel can be represented by 8 bits.,A full screen 256-grayscale graphic at 640 * 480 resolution requires 307,200 bytes.,Color graphics,Color graphic:,display a bitmap image using color,16 color : 1 pixel can have 16 color, need 4 bits,256 color:1 pixel can have 256 color, need 8 bits,16.7 million colors (24-bit or true-color graphic) color:,need 3 bytes to present : Red Green Blue,width,：271,height,：300,color,：2,size,：9.9,KB,width,：271,height,：300,color,：4,size,：19.8,KB,Example of graph,Section C Digital Data Representation,width,：271,height,：300,color,：256,size,：79.4,KB,width,：271,height,：300,color,：,true color,size,：238.2,KB,Example of graph,Section C Digital Data Representation,Computation for storage,To store a true color image,resolution 352288,Color byte 3B,storage= 352288 3=297KB,If enhance image resolution,storage=,768,1024,Decrease the graphic storage,and transmission time,Approximator,: 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 compression,Dithering,: reduce the number of colors in a graphic.,Vector graphic and Digital Video,Vector graphic,Difference 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 screen,Digital video,Composed 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,t1,t2,t3,t4,t5,t6,t7,.,幅值,0011,0101,0111,1001,1011,1101,1110,.,Analog signals technique parameter,Sampling rate,( Hz ex:kHz/kHz),Sampling precision,(bit,ex:8 bits/16 bits,),Track number,(single,、,double,),采样频率11,KHz,8,位量化,采样频率22,KHz,16,位量化,Circuits and chips,What,s a computer chip?,the terms computer chip, microchip, and chip originated as technical jargon for 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 processing,Programs 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 processing,Section D Digital Processing,“,语言,”,是人机交流的工具,程序是用,“,语言,”,写成的计算机可以识别的,“,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言,机器语言,机器指令,0,或,1,代码,与语言习惯差别很大难以学习和记忆依赖机器的类型,汇编语言,用助记符代替机器代码；用变量代替各类地址,克服记忆的难点其他与假期语言类似,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性、不依赖具体的计算机类型,高级程序的编译运行方式,可执行程序,编译程序,高级语言程序,目标程序,连接程序,编译,连接,Compiler,An interpreter converts and executes one statement at a time while the program is running.,执行,解释程序,高级语言程序,解释,Interpreter,高级程序的解释运行方式,What does the conversion process produce?,Instruction set: collection of preprogrammed activities,is 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. add-00000100,Machine language:,can be directly executed by the processors circuitry,Digital processing,A machine code instruction has two parts:,the op code,and,the operand,.,Eg: instruction: add 1,00000100 00000001,Digital processing,Op code,Operand,P31 f1-36,指令的概念,指令,：计算机能够识别并执行的,“,操作命令,”,指令一般由操作码和操作数组成,操作码 目标操作数 源操作数,操作码 操作数,表示功能（操作）,表示操作的对象,Components:,Program Control,C,entral,P,rocessing,U,nit,Arithmetic Logic,Unit (ALU),Main,memory,I/O,Equip-,ment,register,Processor logic,Processor logic,What happens when a computer executes an instruction?(p32 f1-38),Fetch,instruction,4. Increment pointer to the next instruction,3. Execute instruction,2. Interpret instruction,What role does the control unit play?,(p32 f1-39),Processor logic,What does the ALU swing into action?,(p32 f1-40),