大学计算机基础复习资料双语教学英文版Word格式.docx

1、Minicomputers （小型机）Microcomputers（微机）即 personal computer or PCleast powerful, but the most widely used.7. Information can be represented in one of two waysAnalog data（模拟） A continuous representation，analogous（相似） to the actual informationDigital data A discrete representation8. 1 Byte=8 bits，B, KB,

2、MB, GB, TB）:9. Binary（Base 2）Octal（8）Decimal（Base 10） Hexadecimal（16）0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F10.distinguish number system（1） Subscript（下标） （101）2 （101） 8（2）Postfix（后缀）101B 101O 101D 101H11. Converting numberNon-Decimal to DecimalDecimal to Non-Decimalv 102 integer整数（1）短除法（2）从高位

3、到低位逆用210思想v Fraction小数Non-Decimal to Non-Decimal 28 （10 111 011.110 1）2 = （273.64）882 （6754.32）8 = （110 111 101 100. 011）2162 （A7B8.C9）16=（1010 0111 1011 1000 .1100 1001）？12. Binary Arithmetic 12original code （2n11） （2n11） Total number is2n1 n=8 -127 +127Pro：Simple & Direct Cons：Subtraction operatio

4、n may fail （overflow）13Original code and Complement code, to do subtraction减法 in addition（补码的意义正在于把减法做成加法） For positive number：complement = original For negative number: Original: sign bit is 1, the rest is its absolute value Complement: reverse all digits except the sign, the plus 1 Complement of c

5、omplement = original14complement code 2n1 （2n11） Total number is 2n n=8, the range is: -128 +12715Floating point notation to represent very large real numbers and very small real numbers （1）-1.6875=（-1.1011）2=（-0.1101121）2 （2）指数 尾数上数=0 0000001 1 11011000000000000000000 （用八位表示指数位，24位表示尾数位）16In a 32 b

6、its computer, if 8 bits for exponent part and 24 bits for mantissa part, the range of number is 1038 2-150 0 -1038 -2-15016Code of charactersASCII美国信息交换标准码 character setStandard 7-bits, with 128 charactersExtended 8-bits, with 256 charactersUnicode 16-bits, a superset超集 of ASCI17.von Neumannthree ma

7、in ideas about computer *Five basic components *Use binary information *Stored program18The principle of stored program A couple of abilities: store program and then automatic execute program .（存储程序、自动执行程序）Computers use “memory” （primary memory主存） to store program which will be processedv 19Five bas

8、ic components Control Unit Arithmetic/logic Unit （ALU） 运算器 Input devices Output devices Storage primary and secondary storage19CPUcan fetch each instruction in that program from memory one by onedecode the informationGet data if neededand then execute the information until all instructions arefinish

9、ed.巧记有一个全控制，有两个互相传数据和信息，有一个只入，有一个只出20 ALU（运算器）（arithmetic operation logical operations）-（register） CPU Control Unit（directs and coordinates使协调 operations in computer.）-register Random access memory （RAM） temporary or volatile storage Main memory Read-only memory （ROM） -BIOS Basic Input Output System

10、Memory CMOS required every time the computer system is turned on Secondary Storage 外存 CPU不能直接访问注释1 CPU定义 Interprets（翻译） and carries out basic instructions that operate a computer 注释2 ROM cannot be changed 而CMOS can be changed to reflect changes in the computer system注释3 Memory used to store the most

11、 frequently accessed information stored in RAM cache, 21two registers in the control unit:The instruction register （IR） contains the instruction that is being executed.The program counter （PC） contains the address of the next instruction to be executed18#Two steps of a machine cycle: Instruction cyc

12、le and execution cycle22. CPU speed Clock rate Word size Cache Instruction set size（指令集大小） 23. Computers are electronic devices that accept instructions, process input, and produceinformation24.术语：Floppy disk 软盘 Optical disk/compact disk 光盘 Flash disk 闪存盘23System Unit （主机）v Motherboardv Processor CP

13、U ALUv Memory RAM, ROM, CMOS, Cache All data and instructions must be loaded into RAM before they can be executedv Bus data highway between devicesv Expansion slots/cards （扩展槽/卡） to add extra devices video card, sound card, network cardv Port （端口） a plug for a cable that leads to a device usb ports,

14、 RJ-45, VGA port for monitor OS24. 系统软件操作系统实用软件 外壳，命令解释程序 内核注释1Utility software fundamental to computer installations, but not part of the OS.注释2 shell provides an interface through which a human can interact with the computerkernel manages computer resources, such as memory and input/output device强

15、调：System software定义 manage a computer system at a fundamental level25. Every operating system performs three basic functions：（different os also have other specific functions ）manages computer resources, such as 1. memory,2. CPU, and3. processesprovides an interface through which a human can interact

16、 with the computerallows an application program to interact with other system resources26. Managing Resources consists of:Memory managementProcess managementCPU scheduling26.1. Memory management optimizes（优化） the use of RAM26.2-1 A process can be defined as a program in execution.26.2-2 A single use

17、r operating system allows only one user to run one program at a time.A multiuser operating system enables two or more users to run a program simultaneously.A multitasking operating system allows a single user to work on two or more applications that reside in memory at the same time.A multiprocessin

18、g operating system can support two or more processors running programs at the same time.26.3 CPU SchedulingThe operating system determines which process in memory is executed by CPU Nonpreemptive scheduling 无优先调度Preemptive scheduling27.OTHER FUNCTIONS27.1 System Booting Cold boot&Warm bootThe proces

19、s of starting or restarting a computer is called booting27.2 System Shutting DownSleep mode（睡眠）saves any open documents and programs to RAM, turns off all unneeded functions, and then places the computer in a low-power stateHibernate（休眠） saves any open documents and programs to a hard disk before re

20、moving power from the computerUser Interface Device Driver Network Support Performance Monitor System Update28. Types of Operating Systems28.1 A stand-alone operating system（独立操作系统） is a complete operating system that works on a desktop computer, notebook computer, or mobile computing device28.2 An

21、embedded （嵌入式）operating system resides on a ROM chip on a mobile device or consumer electronic device29File A named collection of related dataFile is stored in secondary storage A file is a set of data that has been given a nameFile system The operating systems logical view of the files it manages D

22、irectory A named group of files. Also called a folder30File type Program files（程序文件） - contains instructions to tell the computer what to do.Microsoft Word, Photoshop, AutoCADData Files - not executable and only used with a program. Word document, text file, Excel file, PowerPoint fileText file A fi

23、le in which the bytes of data are organized as characters from the ASCII or Unicode character setsBinary file A file that contains data in a specific format, requiring interpretation（翻译）31The root directory is typically identified by the device letter followed by a backslash（反斜线）32File managementWin

24、dows Explorer（资源管理器） Clipboard（剪贴板） Recycle Bin（回收站）33File Properties（属性）34Path Names Absolute path D:CoursesComputer2011OS.pptRelative path 2011OS.ppt Multimedia35Representing CharacterASCII （America Standard Code for Information Interchange）v Original ASCII uses 7 bits to code 128 charactersv Exte

25、nded to 8 bits for 128 extra characters2. Unicodeuses 16 bits, can represent 216 = 6553436Representing Audiov Sound is generated by the vibration of airv Sound wave is analogv Computers convert sound to digits by samplingv A stereo sends an electrical signal to a speaker to reproduce soundA sampling

26、 rate of about 40,000 times per second is enough to create a reasonable sound reproductionAudio Formats WAV, AU, AIFF, VQF, and MP3 v MP3 is dominant MPEG-2, audio layer 3 file Graphics37Representing Images and Graphicsv Raster（光栅）-graphics The storage of image information is on a pixel-by-pixel（像素）

27、 basis Popular formats BMP （bitmap）, GIF （Graphics Interchange Format）, JPEG （Joint Photographic Experts Group）v Vector-graphics（矢量图） Describes an image in terms of lines and geometric shapes Include a series of commands that describe a lines direction, thickness, and colour. The file sizes tend to be smaller because not every pixel is described 38 A graph is treated as a matrix of dots, which is called pixelsv The number of pixels is called resolution（分辨率）39Color is expressed as an RGB （Red,Green,Blue） v