Summary of final knowledge points and test questions of Introduction to Computers [Summary of nearly 30,000 words·Complete]

Summary of Introduction to Computer Knowledge Points (1)

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Instruction system: A collection of all instructions in a computer. It is an important indicator of the performance of a computer.

In microcomputers,the basic function of the controller is the operand of the instruction.

The USB bus transmits data serially.

Computer network: A computer network is a collection of independent computers connected by communication lines. Its main purpose is to realize data communication and resource sharing.

Computer virus: A set of computer instructions or programs that destroy computer functions or data, affect computer use, and can replicate itself.

Operating system: The operating system is a large-scale system software composed of programs and data structures. It is responsible for the resource allocation, scheduling and management of all software and hardware of the computer, and controls various programs. execute normally and provide a good environment for users to use the computer.

Cache: A storage located between the CPU and the memory. It is characterized by high speed. The purpose is to keep the speed of the storage consistent with the speed of the CPU. match.

Bus: A collection of several signal lines, which is a channel for information transmission between various parts of the computer.

Data structure: Data structure refers to a collection of data elements with a certain structure (relationship). It mainly studies various logical and physical structures of data, as well as the analysis of data. various operations.

Process: An execution process of a program (or program segment) on a given work space and data set. It is an independent process for resource allocation and scheduling by the operating system. unit.

Program Counter: It is composed of several bit flip-flops and logic circuits, and is used to store the address of the instructions to be executed in the memory.

Machine instruction: A command for the computer to perform a certain operation, which can be directly executed by the CPU.

CPU main technical indicators:
1. Word length: The binary number processed by the CPU at one time number of digits.
2. Main frequency: : The clock frequency of the CPU’s internal operation, which is the operating frequency of the CPU during operation.
3. Address bus width: Determines the capacity of the memory that the CPU can access. Different models of CPUs have different bus widths, so the maximum capacity of memory that can be used is Also different.
4. Data bus width: Determines the amount of information transmitted between the CPU, memory, and I/0 devices at one time.
5. High buffering: A memory that can perform high-speed data exchange. It exchanges data with the CPU before the memory.
6. Instruction system: The more flexible the instruction addressing method, the stronger the computer's processing power.
7. Machine reliability: The shorter the mean time between failures, the better the machine performance.

Computer hardware mainly consists of operators, controllers, storage, input devices, output devices and (buses)
1. Operator : Mainly complete arithmetic operations and logical operations.
2. Controller: Realizes the control of fetching instructions, analyzing instructions and executing instruction operations, and achieves regular control of the entire computing process.
3. Storage: It is a component used to store data and programs. It can be divided into main memory (also called internal memory) and auxiliary memory.
4. Input device, output device: : It is a device that realizes the exchange of information between a computer system and a human (or other system). Input devices convert external information into

The information that the computer can receive and recognize is input into the computer, and the output device is to convert the information processed by the computer into information that can be accepted and recognized by people or
other devices.

The operating system is a large-scale system software composed of programs and data structures. It is responsible for the allocation, scheduling, and management of all computer software and hardware resources, and controls the normal execution of various programs. And provide a good environment for users to use computers.

1. Processor management: Realize the allocation and scheduling of processors under multi-program running, so that one processor can serve multiple programs alternately, maximizing the use of the CPU Utilization.

2. Storage management: Manage the main memory of the computer, including allocation and recycling of main memory, protection of main memory, and expansion of main memory.

3. Device management: Management of various external devices (input, output and external memory) of the computer. Specifically, it includes the allocation and recycling of equipment, starting peripheral work, troubleshooting, etc.

4. File management: It is for users to access by name (file name), supports access, retrieval, insertion, modification and deletion of files, and solves file problems. Sharing, protection, confidentiality and other issues.

5. Job management: Provide users with means to control jobs, and implement job scheduling according to certain strategies.

Characteristics of machine language, assembly language, and high-level language
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1. Machine language: It is a computer language expressed in binary code and can be executed directly . Computers can directly recognize and execute programs written in machine language, which is very efficient. The binary code of instructions is difficult to remember, so manually writing machine language programs is tedious and error-prone. Different computers have different machine languages, so the generality is poor.

2. Assembly language: Assembly language programs cannot be directly recognized and executed by computer hardware. They must be "assembled" through the system software of the assembler (assembler). Language programs must be translated into machine language programs before they can be executed by hardware. Usually, the assembly language program is called the source program, and the machine language program obtained after assembly is called the target program.

3. High-level language: High-level language is a computer language that writes programs in natural language that is close to humans. Programs written in high-level languages ​​can run on different computers and are highly versatile. Programming is convenient and simple. The source program written must be "compiled" or "interpreted" to generate a target program before it can be executed on the computer.
The controller is composed of instruction components, timing components and micro-operation control components.

1. Instruction component: including program counter (PC), instruction register (IR), and instruction decoder (ID).

( 1)The program counter is composed of several bit flip-flops and logic gate circuits, which are used to store the instructions to be executed in the memory. address.

(2)Instruction register consists of several bit flip-flops and is used to store instructions fetched from memory

(3)Instruction decoder is composed of gate combination circuits and is used to decode the instruction operation code.

2.Timing component: Arrange a series of micro-operations contained in an instruction into different "timescales" to implement Timing of micro-operations.

3. Micro-operation control component: Integrate the time stamp signal generated by the timing component and the decoding signal generated by the instruction decoder, and issue the necessary commands to fetch and execute the instruction. A series of micro-operation signals.
The respective characteristics of registers, caches, and main memory.

1. Register: Located in the CPU, it is mainly used to store instructions, addresses, data, etc. The speed matches the CPU and the capacity is small.

2. High buffer memory: It is a fast and small-capacity memory that stores instructions and data to be executed by the CPU in the near future to reduce the CPU's access to memory. Improve overall machine performance.

3. Main memory: Stores instructions and data for computer operation. It has a large capacity, but is slower than registers and height buffers.

The execution process of the instruction.
Computer instruction execution is generally divided into two stages: first, the instruction to be executed is taken out of the memory and sent to the CPU, and then the CPU decodes the instruction to determine the operation to be completed by the instruction. Send control signals to each component to complete the operation
to complete the function of the instruction. When an instruction is executed, the next instruction is processed. The first phase is generally called the instruction cycle, and the second phase is called the execution cycle.
In 1946, at the University of Pennsylvania, Mockley and Eckert built the first general-purpose electronic digital computer, ENIAC. Von Neumann mainly proposed "program storage" and "binary".
Marked by the logical components that constitute computer hardware, the development of computers has gone through four stages: electron tubes, transistors, small and medium-sized integrated circuits, large-scale and very large-scale integrated circuits.
Computer systems are developing in the direction of miniaturization, giantization, networking and intelligence.
Microcomputers are based on microprocessors and can be divided into portable and non-portable categories according to assembly form. According to whether the computer is used by the end user, it is divided into stand-alone microcomputers and embedded microcomputers. .

Summary of basic knowledge of computer introduction + test questions and answers (2)

Basic computer introductory knowledge, I hope everyone will study it carefully;

Knowledge points

1. The first computer, ENIAC, was born in 1946 and was a tube computer; the second generation was a transistor computer; the third generation was small and medium-scale integrated circuits; the fourth generation was large-scale integrated circuits;

2. Computer application fields mainly include: scientific computing; information management; real-time control; office and production automation; artificial intelligence, network communications; e-commerce; assisted design (CAI); assisted design (CAD);

3. The information representation form of the computer is binary, which uses Feng. Neumann's ideological principle is expressed in the form of two numbers, 0 and 1, "every two is converted into one"; its basic information unit is a bit, that is, a binary bit. Commonly used conversion units are: 1 B =8bit; 1KB1024B ;1MB1024KB; 1GB=1024MB;1TB=1024GB; 1 Chinese character=2B；

4. Binary conversion algorithm: when converting decimal to binary, divide by two and get she; when converting binary to octal, use three digits as a group, the weight of three digits is equal to the weight of one digit in octal, and convert binary to hexadecimal When working in groups of four;

5. For character encoding, ASCII code is commonly used, and its Chinese meaning is American Standard Information Interchange Code; it was adopted by the International Organization for Standardization ISO and serves as a universal information exchange standard.

6. The computer system consists of two parts: software system and hardware system;

7. The hardware system includes arithmetic units, controllers, memories, input and output devices. The controllers and arithmetic units are combined into a central processing unit (CPU). The memory is mainly divided into internal memory and external and internal memory. The memory is divided into read-only memory (ROM). ) and random access memory (RAM), RAM is lost when power is turned off. External memory mainly includes hard disk (GB), floppy disk (3.5 inches, 1.44MB), optical disk (about 650MB), mobile memory USB flash drive (MB), MP3 (MB), etc.;

8. Software refers to various programs running on hardware devices and their related data. There are mainly system software (operating system, language processing program, database management system) and application software, that is, utility programs (such as WPS, OFFICE, PHOTOSHOP, etc.).

9. The measurement indicators of computer performance include:

10. The development of computer language has gone through machine language, assembly language, and high-level language; the language that computers can recognize is computer language;

11. The resolution of a monitor is the number of pixels that a monitor can display on one screen, and is an important indicator of the quality of a computer. The main common sizes are: 640480 800600, 1024*768

12. Printers mainly include dot matrix printers, inkjet printers, and laser printers;

13. The boot methods include: cold boot: power on, boot into the system; hot boot: CTRL + ALT + DEL, which can also be used to end the task; reset startup method: RESET key;

14. Computer virus refers to a program that is artificially programmed with the ability to self-replicate and hides in executable programs and data files through unauthorized intrusion, affecting and destroying computer security; replicative, destructive, hidden, and contagious sex;

15. Common characteristics of virus infection: the computer starts too slowly than usual and runs abnormally; abnormal messages occur regularly; the device does not respond for a long time or is abnormal when accessing it, such as the printer cannot be online, garbled characters, etc.; the disk space suddenly becomes smaller, or does not work properly. Disk device identification; programs and data are mysteriously lost, and file names cannot be recognized; inexplicable messages and abnormal displays are displayed; frequent crashes, restarts, and failure to start normally; changes in the size of executable files and the appearance of hidden files from unknown sources;

16. Computer virus removal: manual method (DEBEG) anti-virus software (Rising Anti-Virus. KV3000, Nodun)

17. The necessary equipment for Internet access is a modem, which converts the digital signal recognized by the computer into the analog signal recognized by the telephone line transmission;

18. The disk format command (FORMAT) can rewrite the disk and lose information; FDISK is a partition command that can change the disk logic;

19. Computer network refers to the use of communication lines and communication equipment to connect computer systems with independent functions distributed in different geographical locations to each other, with the support of network software, to achieve data communication and resource sharing between each other; so using the network The biggest purpose is to share resources and facilitate data transmission;

20. According to different geographical locations, networks are generally divided into local area networks (LAN), metropolitan area networks (MAN), and wide area networks (WAN); according to topological structures, they are generally divided into: star, bus, ring, and hybrid;

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1. Multiple choice questions

1. The following is not a topological structure of a computer network ()
   A mesh structure B single line structure C bus structure D star structure

2. In the 16*16 dot matrix font library, the number of bytes required to store the font code of each Chinese character is ()
   A 32 B 256 C 4 D 2

3. In microcomputers, the meaning of VGA is ()
   A microcomputer model B keyboard model C monitor standard D monitor model

4. Digital cameras are external devices ()
   A output device B auxiliary storage device C input device D random storage device

5. Among the following storages, the one with the fastest reading and writing speed is ()
   A RAM BHard disk C Optical disk D Floppy disk

6. The most core component in the hardware system of a microcomputer is (CPU)

7. MIPS is used to measure computer indicators ()
   A computing speed B word length C storage capacity D transmission rate

8. Among the following options, which one is not a computer virus (immunity)

9. The goal of computer networks is (resource sharing and information transfer)

10. A device that can be used as both an input device and an output device (hard drive)

11. The following are computer input (mouse, keyboard, barcode reader, cat's eye,), output (monitor, printer, graphics, inkjet printer), and storage devices (hard disk, floppy disk, optical disk, removable memory)

12. At present, the representative application fields of computers include: scientific computing, data processing, process control (computer-aided engineering (CAI)) and CAD-aided design.

13. The correct description of the storage amount is (1MB=1024*1024Bytes)

14. The hardware that a computer must install to connect to the Internet is (modern modem)

15. The essential input and output devices of a computer are (keyboard and monitor)

16. The data and instructions transmitted, stored, and processed inside the computer are all (binary code)

17. The following description of the operating system is incorrect (the relationship between the operating system and the hardware is not as close as the relationship between the application and the hardware)

18. When a computer processes data, it first transfers the data into (memory)

19. The word length of a computer is 4 bits, then the number of data bits that the computer can process is (32 bits)

20. Monitor main performance indicators (resolution)

21. Microcomputer Pentiun4 1G, why does 1G mean? (CPU speed)

22. Inside the computer, all information is (binary)

23. A complete computer system includes (hardware system and software system)

24. TCP/IP includes three important service software: TELNET (Simple Process Terminal Protocol), FTP (Internet File Transfer Protocol), SMTP (Simple Mail Transfer Protocol). The IP address consists of 32-bit binary numbers, divided into four groups, each The group is 8 bits, and the maximum value per bit is 256, so the interval is 0----255;

25. The goal of computer network is to realize that every computer on the Internet has a domain name to distinguish each computer on the Internet. The highest domain name in the domain name is the area code: China: CN, Japan: JP, Taiwan: TW . United States: US, Hong Kong: HK

26. Network transmission media: (1) twisted pair, (2) coaxial cable, (3) optical cable (4) wireless communication

26. The operating system is actually a set of programs that are used to uniformly manage various software and hardware resources in the computer, rationally organize the computer's workflow, and coordinate the relationship between various parts of the computer and between the system and the user.

27. A complete description of the operating system’s functions? Answer: The operating system has five functions: memory management, processor management, device management, file management and job management.

28. The first condition for sending or receiving electronic mail (E-Mail) via the Internet should be that for every electronic mail (E-Mail) address, its correct form is XXXX. @XXX.XX

29. Set the mouse buttons to left-handed and pointer speed to fastest, set the taskbar to auto-hide and the clock on the taskbar to hide. (Start Menu//Settings//Control Panel//Mouse; My Computer//Right-click//Shortcut Menu//Explorer//Control Panel//Mouse) (Start Menu//Settings// Author Country Bar and Start menu)

30. Set the keyboard character repetition delay to be the longest and character flashing frequency to be the fastest. (Control Panel//Keyboard)

31. Change the system time to 19:30 pm on April 20, 2005 (Start Menu//Settings//Control Panel//Date and Time; My Computer//Right-click//Shortcut Menu//Explorer//Control Panel //Date and time) (double-click the taskbar time prompt box //Dialog box)

32. Create a new folder under the C drive folder named ABC and create an empty BMP image file AA.BMP under the folder (My Computer // Explorer // C: File Menu // New // BMP image; File menu // Rename)

33. Delete the T+LETXT file in the C drive folder and empty the Recycle Bin (My Computer//Explorer//C://Select the file and delete it) (right-click the Recycle Bin//Shortcut menu//Empty Recycle Bin or open Recycle Bin//Empty Recycle Bin)

34. Found in D: through search. WAV format sound files and copy them to the C: GUANLI folder, the GUANLI folder is self-created;

35. Place AA in D:. Move the BMP files to C:, AA. BMP files are screen contents from the desktop; (PRINTSCREEN command and cut function)

36. Use the inverse selection command to change the value under D:. DOC format file selection (select first. DOC file, //reverse selection in the edit menu)

37. Find the GUANLI folder in D and share it;

38. Use the discontinuous selection shortcut key to select all .DOC files under D: (use the CTRL key)

39. View the properties of the folder and set them to hidden, and set the file properties to visible; set the XX file to read-only; (select the file//menu bar//properties; or right-click//properties) (menu Bar//Tools//View)

40. Set the extension that hides the default file name to visible; (Menu bar // Tools // View)

41. Create a new AAA under the C disk. BMP file and set the desktop background to C:AAA. BMP (Control Panel//Display; right-click on a blank space on the desktop//Properties)

42. Rearrange the files under D: by name;

43. Set the desktop disk saver to 3D text, and set the text to "I love Jiaotong University Heli Training Center"

44. Set the desktop resolution to 800*600 and change my computer icon;

45. The region is set to English (United States), 4 decimal places (no restart required) (Control Panel//Regional Settings option)

46. Add EPsonLQ-----1600k local printer, and set the printer name to Jiaotong University Heli Xijiao Branch.

47. Added new input method Singapore language and set the sound box to minimum.

48. Create a new D:QQ on the desktop. The shortcut startup method of the EXE file is named "Chat is so nice" and uses the "Send to desktop shortcut"

49. Create D:QQ at the start menu level. Shortcut to EXE files. Name it "Let's have a good chat"

50. To D: QQ. The EXE file creates a shortcut in the same directory.

51. Use the Start menu to search for 192.168.0.254 in Network Neighborhood, and copy the NIT simulation folder under the AAA folder on the machine to the local machine;

2. Word processing questions

(1) Add a column, use the formula to calculate the average temperature and then sort by average temperature in descending order.
(2) Set the font size of the table to a small 4-size, horizontally centered, and the number part to a 4-size font, vertically and horizontally to the right.
The highest and lowest temperature in the city
Beijing 31 20
Shanghai 29 24
Tianjin 31 22
Nanjing 91

3. Word operation questions

1. Replace IT with information industry
2. Add emphasis
3. Draw a table with 4*5 columns and merge three rows and columns 1-2
4. Set the outer border to 1.5 points, the inner border to 1 point, the border to blue, and the shading of the entire table to yellow.
5. Set the document title to official script, with number 4 hollow and red in the center.
6. Set the text to a small 4-size font and copy the text 4 times. The first three paragraphs are merged into one paragraph, and the last two paragraphs are merged into one paragraph.
7. Insert header footer on page X of Y pages, centered.
8. Indent the first line of each text paragraph 0.8cm from the exit, set the second paragraph to two equal columns, 5.7cm wide, and indent the left and right sides of the second paragraph 2cm.
9. Set the entire page to A4, with margins of 2.5cm up and down and 3cm left and right, and finally save it in df\jhjh\uu\99\0876.doc
10. Set the front and rear sections to 10 pounds

4. Web page and email titles

1. Browse the web and store the text content related to the opening of the Olympic Games as GUANLI. TXT file, and send the file as an attachment to…. @163.com, also copied to…. @263.net, the subject is "The new situation will be reported in the follow-up, please pay attention to the follow-up news", the content of the email is random;
2. Browse the web and open www.sina.com/news/index .htm page, download a picture to D:, the file name is Beautiful World.

Summary of detailed knowledge points at the end of the introduction to computer semester (3)

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1.1 Overview
1.1.1 Computers and Information Processing
● Information is data that reflects objective situations, which can be composed of pictures, texts, sounds, and images. and other multimedia forms.
● Digital information: Information represented only by code strings of 0 and 1 is called digital information.
● A computer is an information processing (processing) machine. Computers generally refer to digital computers. Digital computers can accept and process digitized information.
● The information input into the computer can be divided into two categories: data and program: data is the object to be processed; program is the instruction string for processing the data.
● Information processing refers to the encoding, storage, conversion, transmission, detection, etc. of information.
● The information that computers can process includes text, numerical values, graphics, sounds, images, videos, etc.
1.1.2 The working principle and classification of computers
1. The working principle of computers: stored programs, executed one by one (by the Hungarian-American mathematician von Neu Proposed and implemented by Von Neumann).
2. Classification of computers:
● According to information representation and processing methods: digital computers, analog computers, and digital-analog hybrid computers.
● According to computer usage: special-purpose computers, general-purpose computers
● According to computer scale and performance: supercomputer, mainframe, medium-sized computer, minicomputer, microcomputer Machine
1.1.3 The development and application of computers
1. Overview of the development of computers
● The first digital computer in 1946 (ENIAC) came out (born in the United States)
● First generation (46-57 years): Use electron tubes as logic components, delay lines or magnetic drums as memory; generally used in scientific computing and military aspect.
● Second generation (1958-64): Use transistors as logic components, use magnetic cores as main memory, and begin to use external memories such as tapes; create high-level languages.
● The third generation (65-71 years): Integrated circuits are used as the main functional devices, and semiconductor memories are used as the main memory; batch processing, time-sharing and real-time operating systems appear.
● The fourth generation (72- ): The CPU, memory and various I/O interfaces are built on large-scale integrated circuit chips. The application has been extremely extensive.
2. Characteristics of computers:
● Fast computing speed - the computing speed is expressed in the number of operations per second, which is currently as high as billions to several operations per second. One hundred billion times
● High accuracy - The accuracy is expressed in machine word length, that is, the number of bits that can represent data (binary number), which has currently reached 64 bits.
● Have memory (storage) ability - use various memories to store information.
● It has the function of logical judgment - making right or wrong judgments.
● High degree of automation and flexibility - use programs to control automatic computer operations.
3. Application fields of computers:
● Scientific computing (aerospace, bridges, construction)
● Real-time control (production lines, Modern weapons)
● Data processing (database)
● Computer-aided design (CAD), assisted manufacturing (CAM) and assisted teaching (CAI)
● Word processing and office automation
● Artificial intelligence (robots, smart cars)
● Computer network applications (Internet, campus network) a>
1.2 Number system and coding of computers
The number system is the method and rules for expressing numbers; coding is to solve the problem of how to express various information into 0 and 1 codes according to the methods and rules. string problem.
1.2.1 Number system
52. Carry counting system
(1) Decimal counting system: 0-9 ten Numbers are divided into ten numbers.
(2) Binary counting system: There are only two digits, 0 and 1, and every two is entered as one. (0+0=0 0+1=1 1+0=1 1+1=10)
(3) Octal counting system: There are 8 numbers in total from 0 to 7, and every octal one. (7+1=10)
(4) Hexadecimal counting system: There are 0-9, A, B, C, D, E, F, a total of sixteen numbers, every ten Six into one. (F+1=10)
(5) Number representation: (numeric value) Counting system example: (2BF) 16 (Decimal number defaults to no subscript.)< a i=44> (6) Correspondence of each base number: as shown in Figure 1-1. (Try to write the corresponding number at ?) Figure 1-1 53. Conversion between number systems (numbers entered into the computer must be converted into binary ) (1) Convert each decimal number into a decimal number Expand each decimal number according to its general formula (the ones digit is 0), and calculate The result is enough.

(2) Convert decimal numbers into binary, octal or hexadecimal numbers
10→? Use the "division-remainder method" (divide until the quotient is 0, and reverse the remainder to get the conversion result.)

(3) Conversion between binary numbers and octal numbers
2→8 adopts the "three-digit combination" method: using the decimal point as the base point, convert to octal in groups of three digits on the left and right sides If there are any missing digits in the number, use 0s to complete them.
8→2 adopts the "one divided into three" method.

(4) Conversion of binary numbers and hexadecimal numbers
2→16 adopts the "four-digit combination" method: taking the decimal point as the base point, grouping four digits to the left and right Convert to a hexadecimal number, and fill in the remaining four digits with 0s.
16→2 adopts the "divide one into four" method.

1.2.2 ASCII code (American Standard Code for Information Interchange)
● Letters, punctuation marks, special symbols and numbers used as symbols are generally called characters. These characters are uniformly represented by the American Standard Information Interchange Code, referred to as ASCII code.
● ASCII code table lookup method (Appendix 1 on page P311 of the textbook): ASCII code is represented by a 7-bit binary number (or an 8-bit binary number with the highest bit being 0); the columns in the table represent The 654th bit, row represents the 3210th bit, a total of 128 codes. Look up the table in order of column first and then row reading.
● Character sizes are compared based on their ASCII code sizes. ASCII codes of commonly used characters (from small to large): spaces - numbers - uppercase letters - lowercase letters
For example: The ASCII code value of A obtained from the table is (1000001)2=(41)16 =65; From A, it can be deduced that the ASCII code value of F is 70 [a difference of 5];
According to this table, it can be seen that the ASCII code value of A [65] is greater than the ASCII code value of a [97] ] is small, that is, the ASCII code value of lowercase letters is larger than that of uppercase letters.
Figure 1-2
1.2.3 Chinese character encoding
In order to use 0 and 1 code strings to represent Chinese characters, our country has formulated Chinese characters The information exchange code GB2312-80, referred to as the national standard code.
● The national standard code has a total of 7445 characters. There are 3,755 first-level Chinese characters, arranged in Chinese pinyin order; there are 3,008 second-level Chinese characters, arranged according to radicals and strokes.
● Due to the large number of Chinese characters, each symbol of the national standard code is represented by a two-byte (16-bit binary) code.

1. National standard code: 94 rows and 94 columns (0-93), represented by double 7-bit binary numbers with rows first and columns second, that is, the highest bit of the two bytes is 0 (see textbook P77).
2. Location code: It is not very convenient to use binary national standard code to represent, so Chinese characters can also be represented by decimal location code.
   ● The area (row) and bit (column) are each 94 (1-94), represented by a double 2-digit decimal number with area first and digit second. If there are any missing digits, 0 will be added in front.
   ● For details on the location code table, please see Appendix 2 of textbook P312. Figure 1-3 is a partial location code table, such as: Fu 2403; the 2435; each 2487
   Figure 1-3
3. Internal code: It is the code actually used inside the computer to represent Chinese characters. In microcomputers, a two-byte (highest bit is 1) code is often used as the internal code.
4. Interconversion of the three codes: (See Figure 1-4)
   ● Convert the area code and bit number of the area code from decimal to corresponding hexadecimal +2020H That is the national standard code (where H represents a hexadecimal number);
   ● The hexadecimal national standard code + 8080H is the internal code. It can be seen that the highest bit of the two bytes of the internal code must be 1 (the national standard code is 0).
   Figure 1-4
   Example: The area code for large characters is 2083, the national standard code is 1453H+2020H=3473H, and the internal code is 3473H+8080H=B4F3H.
   1.3 Basic computer operations
   There are two types of computer calculations: numerical calculations (the most basic are the four arithmetic operations) and non-numeric calculations (the most basic are logical operations) operation).
   1.3.1 Four arithmetic operations
   The most basic of the four arithmetic operations is addition, and all other operations can be implemented by addition.
   Binary addition rules: 0+0=0 0+1=1 1+0=1 1+1=10
   Binary multiplication rules: 0< /span> Binary multiplication rules: 0< /span> The hardware is mainly composed of five major parts: arithmetic unit, controller, memory, input device, and output device. 1.4.1 Computer hardware system ● The hardware system is the collection of all physical components that make up the computer; the software system is the sum of various programs and documents. ● Computer system includes hardware system and software system. 1.4 Computer system composition NOT 0=1 nnNOT 1=0 (inversion) 3. Logical irregularity (when A is true When, the value of NOT A is false; when A is false, the value of NOT A is true.) 0 OR 0=0 nn0 OR 1=1nn1 OR 0=1 nn1 OR 1=1 (or 0+0=0 0+1=1 1+0=1 1+1=1) 2. Logical OR rule (when either A or B is true, the value of A OR B is true, otherwise it is false.) 0 AND 0= 0,n,0 AND 1=0 nn1 AND 0=0 nn1 AND 1=1 (or 0?0=0 0?1=0 1?0=0 1?1=1) 1. Logical AND rules (when A and B are true at the same time, the value of A AND B is true, otherwise it is false.) The following 0 and 1 are binary codes. Generally, 1 represents the affirmation of the event (true), and 0 represents the negation of the event (false). There are three basic logical operations: AND, OR, and NOT. 1.3.2 Basic logical operations (Table 1.2 on P13) 1=1 0=0 11=0 10=0 0 Binary addition rules: 0+0=0 0+1=1 1+0=1 1+1=10 The most basic of the four arithmetic operations is addition, and all other operations can be implemented by addition. 1.3.1 Four arithmetic operations There are two types of computer calculations: numerical calculations (the most basic are the four arithmetic operations) and non-numeric calculations (the most basic are logical operations). 1.3 Basic computer operations NOT 0=1 nnNOT 1=0 (inversion) 3. Logical irregularity (when A is true When, the value of NOT A is false; when A is false, the value of NOT A is true.) 0 OR 0=0 nn0 OR 1=1nn1 OR 0=1 nn1 OR 1=1 (or 0+0=0 0+1=1 1+0=1 1+1=1) 2. Logical OR rule (when either A or B is true, the value of A OR B is true, otherwise it is false.) 0 AND 0= 0,n,0 AND 1=0 nn1 AND 0=0 nn1 AND 1=1 (or 0?0=0 0?1=0 1?0=0 1?1=1) 1. Logical AND rules (when A and B are true at the same time, the value of A AND B is true, otherwise it is false.) The following 0 and 1 are binary codes. Generally, 1 represents the affirmation of the event (true), and 0 represents the negation of the event (false). There are three basic logical operations: AND, OR, and NOT. 1.3.2 Basic logical operations (Table 1.2 on P13) 1=1 0=0 11=0 10=0 0
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
5. Arithmetic unit: The main component of a computer for performing arithmetic and logical operations.
6. Controller: Retrieve instructions one by one from the memory to control the coordinated work of various components of the computer. It is the command center of the computer.
7. Memory
   ● The storage component of the computer, used to store original data and programs.
   ● The memory is divided into storage units according to 8 binary bits or multiples thereof. Each unit has a number, that is, an address.
   ● Storage capacity is calculated in bytes:
   A. An 8-bit binary number is 1 byte [byte] and is recorded as 1B; 1024 [10 of 2] Power] bytes is recorded as 1KB; 1024KB is recorded as 1MB; 1024MB is recorded as 1GB.
   B. Byte unit conversion relationship: 1GB=1024MB=1024×1024KB= 1024×1024× 1024B
   ● Memory is divided into internal memory (main memory) and There are two types of external memory (auxiliary memory):
   A. Memory is a semiconductor memory, which can be divided into two types: read-only memory (ROM) and random access memory (RAM). What is usually called memory Generally refers to RAM; external memory is mainly magnetic media storage, including disks (floppy disks, hard disks), tapes, read-only CDs, etc.
   B. The CPU can directly access the memory, but the data in the external storage must be transferred into the memory before it can be operated. Therefore, the memory is the center of computer information exchange.
   C. The memory access speed is fast, the storage capacity is small, and the information is lost when the power is turned off; the external memory access speed is slow, the storage capacity is large, and the data can be saved permanently.
8. Input device: Convert original data and programs into code strings of 0 and 1 that the computer can recognize and input them into the computer.
   Commonly used input devices include keyboards, mice, microphones, scanners, light pens, teletypewriters, etc.
9. Output device: converts the information processed by the computer into a familiar form or information that can be recognized by other devices and outputs it outside the machine.
   Commonly used output devices include monitors, printers, speakers, plotters, etc.
   Note:
   ● The controller and arithmetic unit form the core of the computer, which is called the central processing unit (CPU)
   ● CPU and memory Together they are called the host.
   ● Input, output devices and external memory are collectively called external devices.
   Note: Although the disk drive is a storage device, it also has dual functions of input and output, so it can also be used as an input and output device.
   The hardware structure diagram is shown in Figure 1-5 (Textbook P17); the hardware working diagram is shown in Figure 1-6.
   Figure 1-5
   1.4.2 Hardware composition of PC
   PC is the abbreviation of personal computer and a type of microcomputer. First, the IBM PC was launched by IBM.
   1. Host and main chassis
   The main chassis mainly contains the motherboard, interface card, external memory drive, power supply, speakers, etc., as shown in Figure 1-7 And video 1-1 shows
   (1) Motherboard
   The PC’s host and its auxiliary circuits are installed on a circuit board, called the motherboard or motherboard , as shown in Figure 1-8.
   The most important component on the motherboard is the host, that is, the CPU and memory. Figure 1-9 shows the appearance of the CPU and memory module.
   CPU
   Two important indicators of CPU are word length and clock frequency. The word length reflects the length of data that the PC can process simultaneously, which marks the computing accuracy of the computer; the clock frequency reflects the running speed of the PC. The performance indicators of the CPU determine the grade of the computer.
   Memory
   There are three main types of PC memory: ROM, RAM and Cache:
   ● ROM [read-only memory] can only It cannot be read and written, and is used to solidify some important system programs;
   ● RAM [random read and write memory] is the main memory of the PC, which is made into a memory stick and inserted into the socket. Once the computer loses power, all information in RAM is lost. Current configurations generally include 64MB, 128MB, 512MB or higher.
   ● Cache [cache memory]
   A. In order to solve the problem of mismatch between CPU speed [increase very quickly] and memory speed [increase slowly] Bottleneck problem;
   B. Cache is a kind of random access memory with higher speed and higher cost. It is installed between the memory and CPU or both separately;
   C. Part of the data in the memory is placed in the Cache. When the CPU reads and writes data, it accesses the Cache first, and only accesses the memory when the data is not satisfied. This can not only improve the data access speed, but also have a better performance-price ratio.
   Others
   There are also some auxiliary circuits on the motherboard, mainly buses and some registers and their control lines.
   The bus is a channel for data transmission between units within the CPU and for exchanging information between the CPU and the outside.
   A register is a storage unit that temporarily stores data or instructions.
   (2) Expansion sockets and interface cards
   ● Generally configured with 6-8 expansion sockets, interface cards (adapters) used to connect peripherals to the host ) can be plugged into any expansion socket.
   ● Different peripherals have different interface cards, such as display cards, network cards, sound cards, anti-virus cards, graphics accelerator cards, A/D, D/A conversion cards, etc. Nowadays, sound cards, floppy drives and hard drive control cards are generally integrated on the motherboard to reduce the number of interface cards.
   ● The display card is made separately on a circuit board, and different types of display cards must match the corresponding monitors.
   A. According to the display mode, it can be divided into MDA [monochrome display card], CGA [color graphics card], EGA [enhanced graphics card], VGA [video graphics array card], TVGA, SVGA card;
   B. VGA graphic display resolution is at least 640×480 pixels, and up to 256 colors can be selected; TVGA and SVGA have expanded several new standards for character display and graphic display, and the resolution The resolution can reach 1280×1024, and the color can reach true color.
   (3) Disk drive and optical drive
   ● Up to two floppy drives and two hard drives or optical drives can be installed in the main chassis.
   ● They are external devices (external memory), so they must be connected to the host through the drive control card (or directly).
   (4) Power supply
   The regulated power supply installed in the main chassis can convert alternating current (mains power) into low-voltage direct current for supplying various components and keyboards in the main chassis. use.
   2. Keyboard
   The keyboard is the main input device. It has its own microprocessor and has on-off and decoding functions. The keyboard is connected to the same-colored jack on the back of the console via a cable.
   ● Keyboard operation essentials
   A. Reference key positions and finger key positions: A, S, D, F on the left hand, J, K, L on the right hand; a> a> ● Principle: Impact type, the print head has 24 steel needles that click on the ribbon to print the dot matrix onto the paper. Dot matrix printer There are three types of printers: dot matrix printers, inkjet printers and laser printers, as shown in Figure 1-12. 5. Printer ● Each monitor must be matched with the corresponding graphics card. ● There are currently two common monitors: CRT ordinary or flat-screen monitors, and LCD liquid crystal monitors [non-radiation], as shown in Figure 1-11. ● The size of the monitor refers to the length of the diagonal of the screen, commonly used ones are 15"-21". ● Another indicator of the display is the color depth, which is expressed by the number of binary digits that represent color at one point. The more digits, the richer the color levels. Generally, colors above 16M are called true colors. ● The main indicator of the monitor is resolution, which is expressed by the number of dots (pixels) displayed in the vertical and horizontal directions of the screen. The higher the resolution, the clearer the characters and images displayed. 4. Monitor ● Right-click: Press the right button of the mouse ● Double-click: Press the left button twice in quick succession ● Click: Press the left mouse button. If not specified, the mouse button refers to the left button. ● Drag: hold down the left button and move the mouse ● Move: move the mouse without pressing a button The mouse is an important input device. There are two types of mice: two-button and three-button mice, but both use left and right buttons. The mouse arrow will have different shapes in different situations, indicating different meanings. For example, a funnel shape means that the system is busy and please wait. 3. Mouse ● Don’t use too much force, and don’t hold down a key; try not to look at the keyboard, and you can achieve touch typing with regular practice. ● Essentials: Place the index fingers of both hands on the J and F keys (each has a small boss), rest your other fingers on the corresponding keys in turn, and place your two thumbs on the space bar. Use the closest finger to hit each key, paying attention to the return after hitting. ● See Figure 1-10 for the division of labor among the ten fingers.
   B. Correct fingering (see video 2-2 for demonstration)
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   ● Relative performance: low price and low consumption; but poor printing quality, loud noise and slow speed.
   ● Common models: LQ-1600K, etc.
   Inkjet printer
   ● Principle: non-impact type, from many fine The nozzle sprays ink onto the paper.
   ● Relative performance: lower price, good printing quality, low noise; but it consumes a lot of money and the nozzles are easy to clog.
   ● Common models: Cannon, Epson, Lenovo and other brands
   Laser printer
   ● Principle: Using laser scanning technology The output signal is high-frequency modulated and then converted into a dot matrix signal for output.
   ● Relative performance: fast speed, low noise, highest printing quality; but the price is higher.
   ● Common models: Hp LaserJet 6L, etc.
   6. Other external devices
   Scanners, plotters, game sticks, Digital cameras, digital video cameras, etc.
   7. External storage
   The external storage of PC includes floppy disk, hard disk and optical disk drive.
   (1) Floppy disk storage: Floppy disk is separated from the drive
   ● Floppy disk is a magnetic media storage. Depending on the diameter of the disk, floppy disks are available in 3.5 inches and 5.25 inches. species (obsolete).
   ● Speed: The speed of floppy disk is low, only 300 revolutions per minute.
   ● Capacity: 3.5-inch floppy disk has 2 recording magnetic surfaces, numbered 0 and 1; each magnetic surface has 80 tracks, numbered 0-79 from outside to inside; each track Divided into 18 sectors; each sector can store 512 bytes of data. As shown in Figure 1-13, the capacity is: 512B×18×80×2≈1.44MB
   (2) Hard disk storage: The hard disk and the drive are integrated and sealed in a metal box. Hard disk has fast reading and writing speed, large capacity and long life. It is the most important external memory of computer.
   ● The hard disk is composed of a steel alloy disc with a layer of magnetic media on the surface.
   ● Speed: The reading and writing speed of hard disk is much higher than that of floppy disk, reaching 5400-7200 rpm. As shown in Figure 1-14, each side of each disk corresponds to a read and write head. The head is suspended on the surface of the disk (Winchester technology), so the read and write speed is fast and the wear of the head can be reduced.
   ● Capacity: The hard disk is fixedly installed on the same spindle with multiple double-sided platters of the same performance and size. The capacity is generally between 40-300GB.
   Figure 1-14
   (3) Optical disk storage: The optical disk is separated from the drive. Optical disk storage generally refers to CD-ROM. Other types of optical drives include: optical disc burners CD-R, DVD, Combo COMBO [comprehensive], etc.
   ● The optical disc is a plastic disc with an aluminum radiation layer. Due to the use of optical storage technology, the storage density is high.
   ● Speed: The read and write speed of an optical drive is between that of a hard disk and a floppy disk, expressed in times. 1x speed is 150Kbps. If it is 40x speed, the data transfer rate is 150Kbps×40. (b here refers to binary bits, not byte B)
   ● Capacity: generally 650-700MB. Although it is only a single-sided storage, the current most advanced DVD disc capacity has reached 150GB.
   How to use CDs and floppy disks is shown in Video 1-3.

(4) Large-capacity mobile storage device
● USB flash drive [OnlyDisk]: USB interface (hot-swappable), high-capacity storage without driver. It is characterized by small size, light weight, large capacity (64MB, 128MB, 256MB...2GB), fast access speed, and relatively cheap price. It has gradually replaced floppy disks.
● Mobile hard disk: A portable hard disk with USB interface, which has the basic characteristics of a fixed hard disk, as shown in Figure 2-12. The capacity is 20-80GB and the price is relatively expensive.

1.4.3 Computer software system
Software is the sum of all programs and documents.
1. Instructions and command systems
An instruction is a command that instructs the computer to perform a certain operation. A collection of basic instructions constitutes the computer's instruction system.
The instruction consists of two parts: operation code and operand address code. The operation code specifies what operation the computer performs; the address code points out the location where the data participating in the operation and the operation results are stored (a simple address code only has one, and a complex one can have two or three), as shown in Figure 1-15.
Figure 1-15
Types of instructions: operation instructions, transfer instructions, control instructions, input and output instructions, and special instructions. 2. Program
A program is an ordered collection of instructions. 3. Programming language
(1) Machine language
● A collection of machine instructions expressed in binary code. It is a machine-oriented programming language.
● It is the only language that computers can directly recognize. It's fast to run, but hard to remember.
(2) Assembly language
● A language represented by mnemonic symbols. It is also a machine-oriented programming language (low-level language).
● It needs to be translated into machine language before it can be executed.
(3) High-level language
● A programming language close to human natural language. It is a process-oriented and highly versatile language.
● It also needs to be translated into machine language before it can be executed. Commonly used ones include VisualC, VisualFoxPro, VisualBASIC, JAVA, etc. 4. Basic concepts of software systems
Software is the sum of all programs and supporting documents compiled in a computer system for the operation, maintenance, management and application of computers.
Software classification: as shown in Figure 1-14
Figure 1-14 [The blue part of the figure is for general understanding]
5. System software
System software is the most basic software for running, managing, and maintaining computers, and is generally provided by manufacturers.
(1) Operating system
The operating system is a collection of programs that control and manage computer software and hardware resources, rationally organize computer workflows, and provide human-computer interfaces.
Main functions of the operating system: processor management, storage management, file management, and device management.
(2) Language processing program
A program written in assembly language or high-level language is called a source program; the source program must be translated before it can be converted into a computer that can be directly The machine language program executed is called the target program.
There are three types of language processing (translation) programs:
● Assembler: a translation program that is executed after translating the assembly language source program into a target program.
● Interpreter program: a translation program that translates and executes high-level language source programs sentence by sentence.
● Compiler: a translation program that translates the entire high-level language source program into a target program, connects it and then executes it
(3) Utility program: also called support Software is a necessary software tool for machine maintenance and software development.
6. Application software
Software developed to address the specialized problems of various applications. 1.4.4 PC operating system
The operating system is the most basic and important system software. The three most influential operating systems are MS-DOS/PC-DOS, UNIX/XENIX and Windows.

1. From DOS to WindowsXP
   MS-DOS/PC-DOS
   ● DOS is the abbreviation of Disk Operating System, which is a single User, single-tasking operating system. As shown in Figure 1-15.
   ● The Western DOS has been expanded and transformed so that it can process Chinese characters while maintaining the original functions of the Western software. It is called the DOS Chinese platform, also known as the Chinese character system.
   ● DOS versions range from 1.0-6.22, and Chinese platforms include CCDOS, SPDOS, UCDOS, etc.
   Windows
   ● Windows is an operating system based on a graphical window interface.
   ● Windows versions starting with Windows 2.0 and Windows 3.X require DOS support to run;
   ● The Windows operating system Windows95 was released in 1995;
   ● WindowsXP was released in the year of XP, which has stronger network functions, faster speed and good reliability.
   ● The biggest difference between Windows95/XP and DOS is that it supports multi-task operation; it is a single-user, multi-task operating system. In addition, it can also support multimedia information processing such as sound, music, and images.
2. WindowsXP window operating system 1. WindowsXP operating system family
   ● WindowsXP Professional is used for personal computers
   ● WindowsXP Server is used for small and medium-sized enterprises and servers
   ● WindowsXP Advanced is used for large enterprises and servers
   ● WindowsXP Data Center Server is used for large data warehouses and extra large servers
3. Features of WindowsXP
   ● WindowsXP is a multi-user, multi-tasking operating system based on WindowsNT technology.
   ● Enhanced system stability and security, and further improved network function support.
   ● Improved system compatibility with hardware, software and network protocols.
   ● In addition to FAT, a more secure NTFS disk partition format has been added.
   ● Enhanced support for multimedia technology and improved system management.
   ● The interface is more friendly, WindowsXP/XP is bundled with IE5.0.
   6. Basic configurations of PCs of different grades
   See Table 1.3 on P20
   1.4.5 Computer performance indicators
   1. Main frequency (clock frequency): It is the clock frequency of the computer CPU, which determines the computing speed of the computer to a large extent. The unit is Hertz, and the current main frequency is as high as 3.0GHz.
   2. Basic word length: indicates the computing accuracy of the computer. The longer the word length, the higher the calculation accuracy. The unit is a binary digit, and the general word length is 16, 32, or 64 bits.
   3. Memory capacity: Generally speaking, the larger the internal and external memory capacity, the stronger the computer's processing power and the faster the speed, but it must match the speed of the processor.
   4. Computing speed, system reliability, maintainability, compatibility, diagnostic capability, fault tolerance, command system function
   5. Performance-price ratio: software and hardware The higher the price ratio of various performances to the entire system, the better.
   Computer Teacher (395383764) 00:18:55
   1. Single-choice questions (this major question has 10 questions in total, each question is worth 2 points, a total of 20 Points) Only one of the four alternatives listed in each question meets the question requirements. Please fill in its code in the brackets after the question. There will be no points for incorrect selections, multiple selections or no selections.
4. Data transmission rate is an important technical indicator of Modem, the unit is: ( )
   A.bps B.GB C.KB D.MB
   2. Compared with auxiliary memory, which of the following is an advantage of main memory (memory): ( )
   A. Fast access speed B. Cheaper price C. Large capacity D. Price Expensive
   3. FTP is ( )
   A. Secure Hypertext Transfer Protocol B. Secure Sockets Layer Protocol
   C. File Transmission Protocol D. Secure Electronic Transaction Protocol
5. IP sharing is also called ( )
   A. Virtual server B. Virtual client C. Server D. Client
6. The function of Uniform Resource Locator (URL) is ( )
   A. Maintain hypertext link B. Display information C. Send request to server D. Server A.edu B.gov C.net D.com 8. Among the following first-level domain names, the educational organization is ( ) A.HTTP B.SMTP C.IMAP D.POP 7. Post Office Protocol The abbreviation of is ( d ) A.HTML B.SGML C.HTTP D.XML
   6. The standard universal markup language is (　b)
   
   
   
   
   
7. On the Internet, the system that completes the mapping of "name-address" and "address-name" is called ( ).
   A． Address resolution B. Forward resolution C. Reverse resolution D. Domain name system
8. The 100BASE-T standard stipulates that the maximum length of the unshielded twisted pair between the network card and the HUB is ( )
   A.50 meters B.100 meters C.200 meters D.500 m
   Computer teacher (395383764) 23:16:18
   Theoretical question part (20 points in total)
   1. Multiple choice questions (Each question is worth 1 point, total 20 points)
   1. The CPU is mainly composed of arithmetic unit and controller. Which of the following statements is correct ( )
   A . The arithmetic unit is mainly responsible for analyzing instructions and performing corresponding operations according to the instruction requirements
   B. The arithmetic unit is mainly responsible for completing operations on data, including arithmetic operations and logical operations
   C. The controller is mainly responsible for analyzing instructions and performing corresponding operations according to the instruction requirements
   D. The controller directly controls the input and output operations of the computer system
   2 , Which of the following statements is correct ( )
   A. Computer viruses can only be transmitted to executable files
   B. Computer software refers to programs stored in floppy disks< /span> D. Double-click the control menu box in the upper left corner of the application window First question Some famous cavers in my country have tall dome-shaped halls, such as: Huge cave can be divided into several layers. For example, Fozi Rock is divided into three layers, Xing'an Stone Milk Rock, Jiangsu Shanjuan Cave, Yichang Niatong, Guilin Qixing Cave, etc. are also three-layered. Tianquan Cave in Xingwen County, Sichuan can be divided into five layers, while Beijing Shihua Cave has It is known that there are 6 layers, which is the same as Tenglong Cave in Lichuan, Hubei Province. However, according to geological data, it is speculated that there are seven and eight layers of caves below Shihua Cave. It has become the cave with the most layers discovered in my country. The multi-layered cave means that the earth's crust is constantly rising and the groundwater level is constantly falling. The initially formed water caves are constantly transformed into dry caves and rise to a certain height. There are sinkholes connecting the caves at each layer. Huge cave Word part Operational question part (80 points) B. Computer without any software D. Computers equipped only with operating systems A. Single-chip computer B. Single-board computer 20. The so-called "bare metal" refers to ( ) C. Double-click the title bar in the application window B. Double-click the upper right corner of the application window with the mouse Restore button A. Minimize the application window to an icon 19. In Windows , the correct way to terminate application execution is ( ) C. Restore the application window D. Double-click the application icon with the mouse A. Point to the application with the mouse Icon B. Minimize the application window to an icon 18. In Windows, the correct way to start an application is ( ) C. Have the same transmission rate and different transmission distances D. Have Different transmission rates and the same transmission distance A. Have the same transmission rate and the same transmission distance B. Have different transmission rates and different transmission distances 17. Various network transmission media ( ) D. Multimedia computer hardware systems and multimedia computer software systems C. Multimedia input Equipment and multimedia output devices B. Multimedia communication software and multimedia development tools A. Multimedia function card and multimedia host 16. The two major components of a multimedia computer system are ( ) A. Internet B. CERNET C. Novell D. CHINANET 15. According to the communication distance, computer networks can be divided into local area networks and wide area networks. Which of the following networks is a local area network ( ) A. Terminate the current operation B. Reset the system C. Suspend standard Output of the output device D. End command line 14. The function of the control key ^C is ( ) A. cannot be read but can be written B. cannot be read or written C. can only Can't read and write D. Can read and write 13. 3.5-inch floppy disk There is a sliding block on one corner. If you move the sliding block to reveal a small hole, the floppy disk ( ) A, Scroll-Lock B, Num-Lock C, Pgdn D, PrtSc (Print Scorccn) 12. The code that should be used to print the current screen content The control keys are ( ) C. It is 32 binary bits D. It is related to the model of the CPU chip A. It is 8 binary Bit B. It is 16 binary bits 11. The basic unit of data processed by the CPU is word, the length of a word ( ) A. is still running in the background B. temporarily stops running C. Stop running completely D. Error 10. In Windows, after minimizing an application window, the application ( ) A, FTP B, WWW C, BBS D, E -mail 9. In the Internet (Internet), the abbreviation of electronic bulletin board is ( ) A. Sensory media B. Expression media C. Expression media D , storage media 8. CD-ROM belongs to ( ) D. Can be read It cannot be deleted, but new data can be written C. Can be read, can be deleted, but new data cannot be written B. Can be read, cannot be deleted, nor can new data be written A. cannot be read, deleted, or new data can be written 7. The disk is in a write-protected state, so the data in the disk ( ) A. ASCII character B. Chinese character C. Disk file D. Subdirectory 6. One piece A floppy disk with a storage capacity of 1.44MB can store approximately 1.4 million ( ) A, first generation B, second generation C, third generation D, fourth generation 5. Use ultra-large-scale integration Computers manufactured by circuits should belong to ( ) D. In the computer local area, only software resources can be shared, but not hardware resources C. In computer networks, a The transmission medium cannot transmit multiple signals B. Sending information from the terminal into the communication line in an intact form is called modulation and demodulation A. Converting digital signals into signals that are easy to transmit in analog communication lines is called Modulation 4. Which of the following statements is correct ( ) A. 8 B. 16 C. 32 D. Computer Different systems 3. The number of binary digits in a word length is ( ) D. Although the hard disk is installed in the main chassis internal, but it belongs to external memory
   C. The process of starting the computer is the same every time because all the information in RAM will not be lost after shutting down
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   Beijing Yunshui Cave 6 caves, Fujian Jiangle Yuhua Cave 6 caves, Sichuan Xingwen Tianquan Cave 6 caves, Henan Gongxian Snow Flower Cave 6 caves, Zhejiang Tonglu Yaolin Wonderland 7 caves , 7 caves in Longquan Cave in Xuancheng, Anhui, 7 caves in Zhishan Cave in Lincheng, Hebei, 9 caves in Reed Flute Cave in Guilin, Guangxi, 10 caves in Tenglong Cave in Lichuan, and 10 caves in Furongxian Cave in Shaoguan, Guangdong.
   Complete the following requirements:
   1. Set the title text "Huge Cave" to be italic GB2312, size 2, zoom 150%;
   2. Set the title text "Huge Cave" fireworks blooming effect, center alignment;
   3. The font size of the first two paragraphs of text is size 4, and the first line is indented with two Chinese characters; a>
   4. Arrange text using tab stops (tab stop positions: 1.07 characters left-aligned, 15.71 characters left-aligned, 20.71 characters vertical-aligned, 22.86 characters left-aligned, 35.36 characters left-aligned); 4. TCP/IP protocol: 3. Digital signature: 2. Encryption: 1. Virus: 2. Noun explanation questions (this question has 5 questions in total, each question is worth 4 points, a total of 20 points) 6. Save the presentation as a folder named after yourself, with the file name: "05081904". 5. Insert two new slides. 4. Set the color scheme of the slide to the standard one. 3. Enter "Zhang Xiaoli Design" in the upper right corner of the title master. 2. Select the application design template and set the slide template to the "Factory" template. 1. Create a presentation , set to master form. Complete the following operations PowerPoint section 10. Save the table under your name In the folder, the file name is: "05081903" 9. For the filling effect of the background wall, select the default "Looking into the distance"; 8. The background of the chart is set to blue and white. Two-color transition color; 7. The category axis is the household head, and the series is water and electricity bills; 6. Generate columns based on water charge and electricity charge data Type chart: The chart position is B16:I26; 5. Calculate the "room fee" "Charge", "Electricity Consumption", "Electricity Charge", "Water Charge" and other column-related total items (using the SUM function); 4. Calculate the "amount": Amount = room fee + electricity fee + water fee (use SUM function); 3. Calculate "water consumption" and "water bill" (calculation method reference 1, 2); 2. Calculate "electricity bill": electricity bill = electricity consumption × unit price; 1. Calculate "electricity consumption": Electricity consumption = bottom of this month's table - bottom of last month's table ; (All calculation items, if If filled in after manual calculation, no points will be given. All decimals are kept to 2 decimal places) Open the Sheet1 worksheet of the EXCEL material workbook and complete the following operations as required: Excel part 5. After completion, save it in a folder named after yourself. The file name is: "05081902". 4. Set all cells to be vertically aligned in the center. Practical amount = this time - last time, fee payable this time = practical amount * unit price; 3. Merge the three cells in the first row grid, use formulas to calculate data and fill in the table, and set the amount data format to currency format. 2. Set the table column widths to: 2.8, 1.9, 1.9, 2.8, 2.8 cm; 1. Set the table title text "Payment Notice" to bold, size 2, and center alignment, and set the font in the table to size 4 font size; Complete the following requirements: Amount of fee payable this time: Toll collector: Signature: (seal) This time: 524 Unit price: 3.00 Number indicated last time: 498 Practical amount: User number: 3-4-12 Payment Notice Question 2 6. After completion, save it in a folder named after yourself. The file name is: "05081901".
   5. Set the header text to "Huge Cave" right-aligned, and the footer to the current system date and left-aligned.
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   

5. Called symmetric encryption:

3. Short answer questions (this question has 6 questions in total, each question is worth 6 points, totaling 36 points)
1. What is an IP address?
2. Asymmetric encryption?

3. What is a computer network?

4. What is OSI/RM?

5. What is a firewall?

6. What is a network operating system?
7.1 Computer Network
The establishment and use of computer network is the product of the combination of the development of computer and communication technology, and is an important part of the information highway.
7.1.1 Types of computer networks
1. Definition and functions of computer networks
(1) Definition of network a> ● IEEE 802.4 token bus passing access method < /span> The first two are for the purpose of education and scientific research and are non-profit in nature; the latter two are commercial networks. National Public Information and Communication Network (abbreviated as CHINAGBN, also known as Jinqiao Network) China Public Computer Internet (abbreviated as CHINANET) China Education and Research Computer Network (abbreviated as CERNET) China National Computing and Network Facilities Project (NCFC for short) ●Currently, my country has the following four backbone networks to manage international Internet exports: ●China National Computing and Network Facility (NCFC) officially connected to the Internet in April 1994 and established the CN main server setting for the highest domain name in my country. ● The predecessor of the Internet is the ARPAnet (Arpanet) established by the US Department of Defense Vision Planning Agency (ARPA) in 1969, which was first used for military experiments. ● In 1993, the Clinton administration of the United States proposed the construction of an "information highway" (National Information Infrastructure NII). 1. General situation of the Internet 7.1.4 Internet and CERNET 7.1.3 Internal network use of win2000 (omitted) ● IEEE 802.5 token ring transfer access method ● IEEE 802.3 bus access method There are three most commonly used ones: It is a technology used to reasonably complete the allocation of transmission channels when multiple users compete for channel usage rights. 3. Access control method ● Other transmission media: magnetic media (such as disks and tapes), signals within the field of view (such as microwaves and infrared rays) and satellite communications, etc. Optical fiber: used in high-speed local area networks. As shown in Figure 7-4. Coaxial cable: used for long-distance transmission of medium and high-end local area networks and telephone systems. Twisted pair: used for point-to-point communication channels, low-end LAN and telephone systems. ● Commonly used transmission media: ● Transmission media is the carrier of information and a line entity that transmits information from one node to another node. 2. Transmission media ● Broadcasting methods: bus type, satellite type (radio type), and ring type, as shown in Figure 7-3. ● Point-to-point mode: star, ring, tree, fully connected, cross-ring, There are six types of irregular types, (2) Classification of computer network topology ●Link: A line or channel that carries information flow between two nodes. Such as: telephone, telegraph line or microwave. Access node (endpoint): includes computers or terminal equipment and corresponding connection lines, which serve as information sources and information sinks. Transfer node: used for network connection. Such as: concentrator, switch, etc. ●Node: an active device connected to the network. Such as: computers, external equipment, communication control equipment, etc. Divided into two categories: Topology: refers to the geometric arrangement of communication lines and nodes in the network, which is used to represent the overall structural appearance of the entire network and the structural relationship between each module. (1 ) The concept of computer network topology 1. Network topology 7.1.2 Computer network topology, transmission media and access control methods ● Broadcast channels are mainly used in local area networks and can be divided into two categories: static and dynamic. ● Two channels of communication subnet: point-to-point channel and broadcast channel. ● The resource subnet is responsible for information processing, including host systems and terminals. ● The communication subnet is responsible for the transmission of information, including communication processors, terminal controllers, switches and transmission media. (3) Divided from network functions and structures: communication subnet and resource subnet. Both are often used to build a local area network. Closed-circuit television (CATV) networks are broadband local area networks. ● The broadband network uses protected coaxial cables, and the data transmission rate can be as high as 400Mbps. ● The transmission medium of the baseband network uses twisted pairs, flat cables or coaxial cables, and the data transmission rate is below 10Mbps. (2) Divided from the information transmission bandwidth or transmission medium: baseband network and broadband network. ● WAN is developing in the direction of Broadband Integrated Services Digital Network (B-ISDN). ② The data transfer rate is relatively lowest. ① The scope can cover tens of kilometers or more. ● Characteristics of WAN Wide Area Network (WAN) Closed-circuit television (CATV) network is a typical example of a metropolitan area network. ② The data transmission rate is lower than 1Mbps. ① Coverage covers the entire city (generally also called local area network) . Characteristics of MAN Metropolitan Area Network (MAN) WINDOWS2000 (or NT) platform, UNIX or LINUX platform. ● LAN software platform ③ Unique to a certain unit or department, such as campus network. Local area network is currently the most active branch of computer networks. ② Data transmission rate is higher than 1Mbps ① Coverage range from several hundred meters to several kilometers ● Characteristics of LAN Local Area Network (LAN) (1) Divided from the scope or scale of use: local area network (LAN), metropolitan area network (MAN), wide area network (WAN) . 2. Classification of networks ● Provide users with various comprehensive services and provide communication means for widely distributed users. ● Improve system compatibility, facilitate user expansion, and improve processing capabilities. ● Configure the system reasonably to save the cost of software and hardware equipment. ● Improve system security and reliability. ● Load balancing, collaborative work, and distributed processing. ● Centralize the processing of data information in the system. ● Reasonable allocation and adjustment of system resources. (2) Basic functions of the network
A computer network refers to a collection of independent computers that are connected to each other and are designed to share resources.








































































● Foreign countries are researching, developing and testing the next generation broadband Internet using new technologies, which is called Internet2 by academic circles.
● The difference between the meanings of Internet and internet:
① The Internet refers specifically to the world’s largest open computer network developed based on the American ARPAnet . Mainly adopts TCP/IP protocol communication.
② The internet generally refers to a large network composed of multiple computer networks connected to each other, functionally and logically.
③ The Chinese translation of Internet is Internet, and the Chinese translation of Internet is Internet. The Internet is a type of Internet.
2.CERNET
● CERNET (China Education and Research Network) is a demonstration project of China’s education and scientific research computer network. It was approved by the State Planning Commission in August 1994. The former State Education Commission presided over the implementation.
● Overall construction goals of CERNET
● CERNET will build a three-level network including the national backbone network, regional network and campus network. As shown in Figure 7-5.
● The network center of the CEKNET backbone network is built at Tsinghua University.
● The campus network of our school is a subnet of Gigabit optical fiber backbone under CERNET, connected to the central node in northern Guangxi (Guangxi Normal University) through 100Mbps optical fiber.
Figure 7-5
3. Preliminary use of the Internet
(1) Basic working principles of the Internet
Due to the huge scale of the Internet, it is necessary to solve problems that do not need to be considered in the local area network:
① Communication line issues: Local area networks are usually laid by users. The Internet needs to connect computers around the world, and the network construction projects are undertaken by postal and telecommunications departments or large telephone and telegraph companies.
② Communication protocol issues: Local area networks usually connect computers of the same type. There are many types of computers on the Internet, and communication between different computers must be considered. The common language used for communication on the Internet is the TCP/IP protocol.
● The composition of TCP/IP: TCP (Transmission Control Protocol) and IP (Internet Protocol).
● How TCP/IP works:
The lower level is the IP protocol (specifies the structure of the transmitted information packet), which requires the computer to break down the information into shorter information packet is sent. The information includes text and IP address. The TCP protocol is at the upper layer of the IP protocol to prevent information packet loss and perform error checking on IP packets.
(2) Address format on the Internet
① Internet host number
● Any computer connected to the Internet, called the host.
● The computer's host number consists of a 32-bit binary number (4 bytes), called the host's IP address.
● IP address is the unique identifier of a host in the Internet network. Duplication of IP addresses in the same network is not allowed.
● The current IP protocol version is IPV4 (32 bits). The new generation Internet2 uses the IPv6 protocol, and the address length is expanded to 128 bits.
Example: The IP address (host number) of a certain host is 11001010 01100000 11000000 00100010
Divide it into 4 groups of 8 digits each, separated by decimal points . Generally, each group is represented by a decimal number, with the value ranging from 0 to 255, as shown in Figure 7-6.
● Two addresses, 0 and 255, have special uses in binary (for broadcasting). The actual range used in each group of numbers is 1 to 254.
Figure 7-6
② Network number on the Internet
●The IP address consists of two parts: network identification (network number ) and host ID (local host number), as shown in Figure 7-7.
Figure 7-7
●Networks are divided into three categories according to scale: the network number represents the type of network.
Large network (Class A): The first number is <128 (begins with binary 0).
The first segment of the IP address is the network number, and the last three numbers are is the local host number. As shown in Figure 7-8.
Figure 7-8
Medium-sized network (type B): the first number range is between 128 and 191 (starting with binary 10) < a i=38> The first two segments of the IP address are the network number, and the last two segments are the local host number. As shown in Figure 7-9. Figure 7-9 Small network (Category C): The first number range is between 192 and 223 (starting with binary 110) < a i=41> The first three segments of the IP address are the network number, and the last segment is the local host number. As shown in Figure 7-10. Figure 7-10 Thinking: What type of network does the host number 202.193.64.34 belong to? What are its IP address, network number, and local host number? ③ Internet host name - domain name ● IP addresses are abstract and difficult to remember, so the host can also be identified by naming, which is referred to as domain name system (domain name system) The English abbreviation is DNS). ● The letters in the domain name can be in any case. The rightmost part of the domain name must comply with international standards (see P245), and other parts can be selected. Like IP addresses, domain names cannot have the same name in the same network. . ● When sending information, the domain name server (the English abbreviation is also DNS) converts the domain name of the host into an IP address. ● The area (rightmost part) in the domain name is divided into two categories: One type consists of three letters and is suitable for the United States; Classes are composed of two letters and apply to countries other than the United States (see P245). For example: the host number 202.193.64.34 mentioned earlier is named gliet (the English abbreviation of Guilin Institute of Electronic Industry), with the institution name and region name on the right, separated by decimal points. The domain name of the obtained host is: gliet.edu.cn. In the World Wide Web (WWW), the URL is represented as http://www.gliet.edu.cn (3) Basic Internet service mode ① Electronic mail (E -MAIL): Information exchange ② File transfer (FTP-File Transfer Protocol): File exchange ③ Remote login (TELNET): Operate other computers on the local machine ④ Comprehensive information service (GROPHER): menu-based information query ⑤ ARCHIE: FTP server retrieval ⑥ Wide Area Information Service System (WAIS): Information retrieval based on keywords ⑦ World Wide Web (WWW): Information retrieval based on hypertext format





















⑧ Electronic News (USENET NEWS): an electronic bulletin board for disseminating news
(4) Internet access method:
① Telephone dial-up ( UNIX host or SLIP/PPPP protocol)
② Packet Internet (UNIX host or TCP/IP protocol)
③ Dedicated line Internet (DDN, ADSL, ISDN): To access the Internet through a dedicated line, users need to apply for a dedicated Internet line and router.
7.1.5 Browsing the Internet
● The World Wide Web (World Wide Web-WWW or Web) is an information retrieval tool on the Internet.
● WWW adopts client/server working method.
● The program used by the client is called a Web browser. For example: Internet Explorer (IE browser for short)
● The picture seen by the browser is called a web page (Web page); multiple related Web pages together form a Web site.
● The computer where the Web site is placed is called a Web server.
1. Setting up the Internet
● Setting up the Internet refers to connecting a personal computer to the Internet through the above three different access methods according to the existing network software and hardware configuration.
● In IE, you can select menu Tools/Internet Options to set the Internet. The setting dialog box is shown in Figure 7-13.
Figure 7-13
2. IE5.0 function overview
① Browse multimedia information on the Internet, including text, sound, images, videos, etc.
② Carry out text typesetting.
③ Access almost all Internet resources.
④ Receive and send emails.
⑤ Customize history records to quickly return to web pages you have browsed.
⑥ Collect your favorite Web sites (make bookmarks) so that you can quickly access it in the future.
⑦ Automatically process interactive tables.
⑧ Read news on the Internet and publish your own articles on the Internet.
⑨ Ensure the security of information transmission and data reception on the Internet.
3. Use of IE5.0
(1) Start IE5.0
Start the Internet Explorer program in the same way as other applications.
The window composition of IE 5.0 is shown in Figure 7-14.
Figure 7-14
(2) Browsing the Internet
Browsing the Internet is divided into two situations:
① Browse different sites
Enter the IP address in the address bar or use the menu File/Open, as shown in Figure 7-14.
Figure 7-15
② Browse different web pages of the same site
●The text option of the hyperlink on the entry page or Picture, or enter content in the dialog box given on the page.
●Commonly used tool buttons, as shown in Figure 7-16.
Figure 7-16
4. Using search engines
● Search engines are sites that some Internet service providers provide users with retrieval services.
● The user only needs to enter the topic (keyword) of the information to be found, and the search engine will search for websites containing the keyword information, as shown in Figure 7-17.
Figure 7-17
7.1.6 Sending and receiving emails
● Email (E-mail) is a A modern communication method that uses computer networks to transmit information.
● The computer that processes email on the Internet is called a mail server.
● Email address (E-mail address) format: username@email server
● You can send and receive E-Mail using tools (such as Outlook Express , FOXMail, etc.), WEB mode can also be used.
1. Create your own email address
● Apply for your own email address from the mail service provider: you can apply for it from the post office or from different websites (For example, the email service function is provided in "Dreams Come True" on our school's homepage).
● Username and password must be provided when applying.
For example: [email protected] 　　
Among them, wanghua is the user name; dreamer.glit.edu.cn is the email server name.
2. Use WEB to send and receive emails
After logging in with your user name and password, you can receive and send emails.
3. Use the Outlook Express tool to send and receive emails
(1) Set up the account
① Start OUTLOOK.
② Select the menu Tools/Account or the Set Email Account entry in the main window.
③ Click the Mail tab in the Internet Account dialog box and select Add/Mail, as shown in Figure 7-18.
④ Enter the name;
⑤ Enter the E-mail address;
⑥ Enter the SMTP and POP3 server names respectively (after the @ character string), for example, our school’s email server is dreamer.glit.edu.cn;
⑦ Enter the user name and password to complete the setting.
Figure 7-18
(2) Sending and receiving emails
① Send new emails
After starting Outlook, click the New Email button in the toolbar, compose the email and send it, as shown in Figure 7-19.
② Receiving and reading emails
Generally, emails will be received automatically when starting Outlook; if you want to receive them manually, you can click the Send/Receive tool button or select the menu tool /Send and receive.
③ Reply to an email Select the email you want to reply to in the mailing list, click the Reply to Author tool button, and after editing the email, click the Send/Receive tool button. As shown in Figure 7-20. 7.1.7 File transfer ● File transfer (FTP) refers to transferring files from the local machine to a remote host on the network (uploading files) or taking files from a remote host to the local machine (downloading files).
● The remote host on the network is called an FTP server.
● There are several methods for file transfer. For example, the special file transfer tool software Cutftp, direct operation of FTP with IE browser, the file transfer tool FTP that comes with Win2000, etc.
1. Operation of CutftpFTP tool software
(1) Start Cutftp
(2) Use of Cutftp
● Upload: Transfer files (folders) in the local host to the FTP server middle.
Select the target location in the server window (right), find and right-click the corresponding file (folder) in the local disk window (left), and select the upload option.
● Download: Transfer the files (folders) in the FTP server to the local host.
Select the target location in the local disk window (left), find and right-click the corresponding file (folder) in the server window (right), and select the download option.
The operation interface is shown in Figure 7-21.
Figure 7-21
2. FTP operation in IE browser
(1) Connect to FTP server a> ● Stimulability ● Latentness ● Hiddenness ● Infectiousness (2) Characteristics of computer viruses: ● Virus stimulation module (providing stimulation mechanism) ● Virus infection module (providing regeneration mechanism) ● Virus installation module (providing latent mechanism) (1) Computer viruses mainly consist of three modules: 2. Characteristics of computer viruses ● The people who create computer viruses are both computer masters and hateful criminals. ● Computer viruses hide in the data resources of computer systems through unauthorized intrusion. ● Computer viruses (CV-Computer Viruses) are a set of computer instructions (small, artificially designed code) that destroy computer functions, programs and data, affect computer use, and can replicate themselves. ). 1. What is a computer virus? 7.3.1 Characteristics of computer viruses 7.3 Computer viruses and their prevention and treatment 7.1.8 BBS (omitted) Perform related FTP operations at the ftp> prompt. (omitted) (2) Related operations on the server ③ Enter open and the server name or IP address after the ftp> prompt, and enter Username and password. ② Type FTP in the run dialog box and press Enter ① Click on the desktop Start/Run (1) Connect to the FTP server 3. Operation of the file transfer tool FTP that comes with Win2000 Download: Copy the files (folders) in the server to a folder on the local disk. Upload: Copy the files (folders) in the local disk to a folder on the server. Once the connection is successful, you can operate the server like a local disk. 2) Related FTP operations Method 2: Enter the IP address of the FTP server along with the user name and password in the address bar of the IE browser. As shown in Figure 7-23.
Method 1: Enter the IP address of the FTP server in the address bar of the IE browser and press Enter, as shown in Figure 7-22. Then select the menu File/Login and enter the username and password of the FTP server in the pop-up menu. 7.3.2 Classification of computer viruses 1. Classification according to the harmful nature of computer viruses (1) Benign viruses (2) Malignant viruses 2. Classified according to the ways in which computer viruses invade the system (1) Source code viruses (invading high-level language source programs) (2) Intrusion viruses (invading target programs) a> 7.4.1 The importance of computer information security 2. Main factors affecting computer information security The implementation of the “Information Highway” plan has transformed information from closed to socially shared. While people share resources conveniently, it also brings hidden dangers to information security. Therefore, it is necessary to take effective information management measures at the macro level and solve the technical problems of information security and confidentiality at the micro level. 1. Problems caused by the “information highway” Information security is very important in the information age, mainly in the following aspects: 7.4 Computer information security knowledge 5. Commonly used anti-virus software ● Special anti-virus tool software: KV3000, Rising, Kingsoft Antivirus, etc. ● General tool software: difficult to operate and low in efficiency. (2) Anti-virus software technology Mainly computer anti-virus cards. (1) Anti-virus hard technology 4. Computer anti-virus technology ● Back up important data to reduce losses ● Frequently check the programs in the system for viruses ● Use a virus firewall system when using the network ● For the system Software should be write-protected ● Do not open emails from unknown sources at will ● Avoid installing various game software into the computer system ● It is strictly prohibited to use programs of unknown origin, and external data and programs must be checked for viruses. 3. Measures to Prevent Computer Viruses ● The machine makes abnormal sounds ● Chinese characters are displayed abnormally ● Important areas of the disk are damaged, causing abnormal system usage ● The size of the file changes (2) Infection through machines (hard disks) ● Files are accidentally deleted or file contents are tampered with ● Frequent unexpected crashes or restarts ● The machine runs significantly slower ● Abnormal system startup ● Abnormal screen displayThe main manifestations are: 2. Symptoms of computer virus (3) Infection through the Internet (1) Infection through floppy disks or removable disks (such as USB flash drives) 1. Channels of infection for computer viruses 7.3.3 Prevention and treatment of computer viruses (2) Viruses transmitted by executable programs (files type virus) (1) Viruses transmitted by disk boot sectors (boot viruses) 3. Classified according to the way computer viruses are transmitted (4) Shell virus (although it does not invade the program itself, it can be infected by the program as it runs) Activate) (3) Operating system virus (invading the operating system to gain system control)
















































































(1) Three characteristics of computer information system security:
● Confidentiality (to prevent unauthorized disclosure)
● Integrity (to prevent unauthorized disclosure) Authorized modification)
● Availability (preventing unauthorized access)
(2) The vulnerability of computer information systems is mainly manifested in three aspects: hardware, software, data.
3. Computer crime has constituted a direct harm to information security.
Computer crime has become an international problem and has caused serious harm to society. The main forms of computer crime are:
● Illegal intrusion into information systems and theft of important business secrets;
● Deliberate attacks on information systems, such as spreading viruses or destroying data; a> ● 1997 The new "Criminal Law" that was implemented on October 10, 2019, specifically added some relevant provisions regarding the use of computers to commit crimes ● "Decision of the Standing Committee of the National People's Congress on Punishing Copyright Crimes" implemented on July 5, 1994 ● Implemented on October 11, 1991 "Computer Software Protection Regulations" ● The "Copyright Law of the People's Republic of China" passed by the Standing Committee of the Seventh National People's Congress on September 7, 1990 and implemented on June 1, 1991 Mainly include: 2. Regulations on intellectual property rights ● "International Networking of Computer Information Networks" issued by the Ministry of Posts and Telecommunications Measures for the Management of Entrance and Exit Channels" and "Measures for the Management of China's Public Computer Internet International Networking" ● "Regulations on the Security Management of International Networking of Computer Information Systems" issued by the State Administration of Security in 2000 ● "Security Protection of International Networking of Computer Information Networks of the People's Republic of China" issued by the Ministry of Public Security in 1997 Management Measures" ● "Notice of the Ministry of Public Security on the Registration of International Networked Computer Information Systems" issued by the Ministry of Public Security in 1996 ● "Interim Regulations of the People's Republic of China on the Management of International Networking of Computer Information Networks" promulgated and implemented by the State Council in 1996 ● Promulgated and implemented by the State Council in 1994 "Regulations of the People's Republic of China on Security Protection of Computer Information Systems" 1. Regulations on computer information system security 7.4.3 Computer information security regulations ● Cryptography forms two types of cryptography systems: traditional cryptography systems and public key cryptography systems. ● The development of cryptography has gone through two stages: one is the classical cryptography stage; the other is the modern cryptography stage. ● Cryptography embodies the three elements of data security: confidentiality, integrity and availability. ● In computer information security systems, cryptography is mainly used for data encryption and also for communication confidentiality. ● Encrypting data is the most effective method to ensure data security. 2. Data security technology for computer information systems ● Fault tolerance (mirror method) ● Auditing (log tracking) ● Anti-repudiation (both sending and receiving parties must confirm) ● Encryption (cryptography technology) ● Data integrity (prevention of illegal writing, data association, etc.) ● Access control (Usage permission setting) ● User identification and authentication (password, fingerprint recognition, etc.) ④ Functions of network security protocols: ● SSL is TCP /Security protocol over IP communication protocol. ● SHTTP is used to maintain communication security with the Web server; ③ SSL/SHTTP technology An authentication method (security protocol) that checks both users (sender and receiver). ② Kerberos technology ● Firewall is not only a hardware device, but also a software technology and communication protocol. ● The core part of the firewall structure consists of filters and gateways. ● There are two typical implementation methods of firewall: one is installed in a dual-port host system and connected to the internal network; One is to install in a public subnet. Figure 7-24 ● It is to set up a set of isolation devices between the protected network and the external network to provide a geographically concentrated network with the ability to resist external attacks, as shown in Figure 7-24 . ● It is one of the most widely used network security technologies today. ① Firewall (Firwall) technology ● Currently there are several representative network security technologies and protocols: Firewall (Firwall) technology, Kerberos technology and SSL/SHTTP technology, etc. ● Network security technology is computer information security technology Foundation. (2) Network security technology ● Reduce the access and use of computer systems by unauthorized users; ● Reduce the information leakage caused by electromagnetic radiation of the computer system; ● Reduce the negative impact of the external environment on the operation of the computer system; ● Reduce the impact of natural disasters on computer software and hardware damage; Physical security technology usually takes the following measures: (1) Physical security technology System security technology of computer information systems is divided into two parts: physical security technology and network security technology. 1. System security technology of computer information systems Computer information security technology is divided into two levels: the first level is computer system security, and the second level is computer data security. 7.4.2 Computer information security technology ● Illegal access to information systems, occupying system resources or illegally modifying data, etc.
● Illegal copying, publishing and dissemination of illegal works;