The person who can give you answers after class, The Basic Course of College Computer edited by Lu Hanquan, Zhejiang University Press! !

Practice and refer to the answers

Chapter 1 Overview

Short answer questions:

1. Computer is a kind of modern intelligent electronic equipment, which can automatically and quickly perform a large number of numerical calculations and various information processing according to pre-stored programs.

2. The five components of a computer are input, storage, processing (operation), control and output. Input is used to send the user's programs and data to the computer; The memory is used for storing programs and data; Processing is used for arithmetic and logical operations and data processing; Control is used to control the work of computer components; Output is used to tell the user the result of the processing.

3. The elements of an information system are: hardware, software, data/information, people (users), process (processing) and communication.

4. The main features of computers are: high-speed and accurate calculation ability; Accurate logical judgment ability; Strong storage capacity; Automatic function; Network and communication capabilities, etc.

The content of computer science research is computer system and computer application. The system includes algorithm and data structure, programming language, architecture, operating system, software methodology and software engineering, human-computer interaction and so on. Applications include numerical and symbolic computation, database, information processing, artificial intelligence, robotics, graphics, organizational informatics, bioinformatics and so on.

6. The word computer culture basically appeared in the late 1980s. Computer culture means being able to understand what a computer is and how to use it as a resource. Not only should you know how to use the computer, but more importantly, you should know when to use it.

7. Computers can be divided into supercomputers, large and medium-sized computers, minicomputers, workstations and microcomputers, and microcomputers can be divided into desktop computers, mobile (portable) computers and embedded computers. The computing speed of supercomputers is generally tens of billions or even tens of billions of floating-point operations per second; Large and medium-sized computers generally run at hundreds of millions of orders of magnitude per second; The running speed and storage capacity of small computers are lower than that of mainframes; Workstation is a single-user computer with strong function and performance, which is usually used to deal with demanding applications. As a desktop system, microcomputers are especially suitable for personal transaction processing, network terminals and other applications.

Multiple choice question:

1、E 2、C 3、B 4、BDFJLE 5、C 6、ABEFH

7、B 8、D 9、A 10、C 1 1、A 12、B

Chapter II Information Representation and Logical Basis

Short answer questions:

The 1. number system is also called "counting (or counting) system". Generally speaking, the composition method of each digit in a multi-digit number and the carry rule from low to high are called the number system. The three basic characteristics of number system are: (1) A number system based on R has R- 1 digits; (2) The maximum number is r-1; (3) The counting rule is "one for every r".

2. The operation rule is to enter 1 in the high bit when the binary bit count reaches 2. The addition is: 0+0 = 0,0+1 = 1,1,1+1=10;

The multiplication operations are: 0 × 0 = 1, 0 × 1 = 1 × 0 = 0,1×1.

3. the method of converting decimal integer into r number is to divide by r and take the remainder.

4.6D = 1 10B 12D = 1 100 b 1024d = 1000000000 b 0.25d = 0.0 1B 7. 125d = 1 1.0065448

5. To convert R-ary numbers into decimal numbers, please use the weighted expansion:

Where: n: integer digits; M: decimal places; A: The number 0, 1, ... n-1; R is the cardinal number; Ri weight coefficient

6.(5678. 123) 10=5× 103+6× 102+7× 10 1+8× 100+ 1× 10- 1+2× 10-2+3× / kloc-0/0-3 (32 1.8) 10=3× 102+2× 10 1+ 1× 100+8× 10- 1

( 1 100.0 10 1) 2= 1×23+ 1×22+0×2 1+0×20+0×2- 1+ 1×2-2+0× 10-3+ 1×2-4 ( / kloc-0/00 1 1 1.000 1) 10= 1×25+ 1×22+ 1×2 1+ 1×20+ 1×2-4

7. 10 10B = 10D 10 1 1 10 1 1 1 1 1 10 1065438 = 157D 0. 1655438

10.0 1B = 2.25d 10 10.00 1B = 10. 125d

8. Each 3-digit binary number corresponds to 1 digit octal number, and it is an integer from the decimal point to the left. If the highest digit is less than 3 digits, you can add zero; Decimal number on the right, the lowest digit is less than 3, and 0 must be added after the lowest digit.

9. Each 4-digit binary number corresponds to 1 digit octal number, which is an integer from the decimal point to the left. If the highest digit is less than 4 digits, you can add zero; Decimal number on the right, the lowest digit is less than 4, and 0 must be added after the lowest digit.

10. 100 10 1 1.00 1 1 1 1 1B = 233. 154 o = 9b . 36h 10 10 1065438

1 1 . 75 . 6 12O = 1 1 10 1 . 1 1000 10 10 10 1B = 3D。 C5H 64A。 C3FH = 1 100 100 1 0 10. 10000 1 1 1 1 1 1 1 1 1B = 3 1 12.600

12. The original code of a positive number is the same as its true value, the original code of a negative number is the absolute value of the true value of this number, and the sign bit is 1. The definition of anti-code is that the anti-code of a positive number is equal to its original code; The complement of a negative number, the highest bit (sign bit) is 1, and the other bits are bitwise negated. The definition of complement is that the complement of a positive number is equal to its original code; The complement of a negative number is equal to its complement plus 1 (add 1 from the lowest bit and consider carry, but carry does not change the sign bit).

13.0.11:original code: 0. 1 100 1, and anti-code: 0.1/.

-0. 1 100 1: original code: 1. 1 1, complement:1.00/kloc-0.

0.111:original code: 0.111,inverted code: 0.160.

-0.111:original code:1.11,anticode: 65438.

0.567D≈0. 100 10B: original code: 0. 100 10, complement: 0. 100 10.

-0.567d ≈-0.10010b: original code: 1. 100 10, anti-code:10/.

14. In order to make the number it represents meet the actual needs, the fixed decimal point method is adopted to represent the number and its operation. There are two commonly used digital representation formats in general-purpose computers: fixed-point format and floating-point format. Fixed-point format allows a limited range of values to fix the decimal point in a certain position. For the convenience of handling, it is generally divided into fixed-point pure decimal and fixed-point pure integer. Floating point representation, that is, the position of decimal point is floating, and a floating point number is divided into two parts: sequence code and mantissa.

15. Move left by n bits: multiply by 2n; Shift n bits to the right: divide by 2 n (rounding)

16. Assuming that the total number of digits that a number can use is 8, then: the number symbol has 1 digit, the sequence symbol has 3 digits, the sequence code has 3 digits, and the mantissa remains 4 digits. The maximum number should be 0.011.1,that is,+0.11* 2+3 = 0.9375 * 8.

17.BCD code is a binary code of decimal number, also known as binary-decimal code, that is, the decimal number is converted into binary, but different from ordinary conversion, each decimal number 0-9 corresponds to a four-bit binary code.

18. There are many Chinese characters with rich attributes, so the Chinese character coding system is also complicated, which mainly includes: Chinese character internal code, Chinese character exchange code, Chinese character input code and Chinese character font code.

19.( 1) Chinese character internal code: it is the representation method of Chinese characters in computer Chinese character system and the basic code of computer Chinese character system. (2) Chinese character exchange code: it is the code standard for Chinese character information exchange (such as internal code). (3) Chinese character input code: it is a variety of coding systems used to input Chinese characters on a computer standard keyboard. (4) Chinese character font coding: used for printing and outputting fonts and font codes of various styles.

20. Proposition refers to a declarative statement that has concrete meaning and can judge whether it is true (T) or False (F). The basic logical conjunctions in propositional calculus are AND, OR and NOT.

2 1. Propositional formula is a formula that connects propositional arguments with logical connectors. On the premise that the two formulas are equivalent, taking the values of each group of independent variables will get the same result.

22.

B.C.

0 0 0 0 0 0 0

0 0 1 0 0 0 0

0 1 0 0 0 0 0

0 1 1 1 0 0 1

1 0 0 0 0 0 0

1 0 1 0 1 0 1

1 1 0 0 0 1 1

1 1 1 0 0 0 0

23.

Actually, the formula can be simplified.

Multiple choice question:

1、B 2、C 3、B 4、A 5、A

Chapter 3 Computer Architecture

Short answer questions:

1. The computer system consists of hardware system and software system. Computer architecture mainly studies hardware composition, Feng? Neumann architecture is also called Feng? Neumann model, mainly: (1) The computer has five components, namely, input, storage, processing, control and output. (2) Computer programs and data needed for program operation are stored in the memory of the computer in binary form. (3) The computer program is executed by the computer controller according to the instruction sequence of the program.

2. The computer hardware system consists of arithmetic unit, controller, memory, input device and output device. According to subsystems, it can be interpreted as three subsystems, namely, processor subsystem, memory subsystem and input-output subsystem.

3. Generally, the storage system consists of two parts: high-speed main memory and low-speed auxiliary memory. Its basic working principle is to store programs and data in auxiliary memory, and the executed programs are transferred from auxiliary memory to main memory for running. After running, the program and data are saved or stored in the auxiliary memory.

4.RISC is called reduced instruction set computer. Removing some unusual instructions from the instruction system reduces the complexity of the processor circuit and improves the execution speed of the whole computer, but the program design is relatively complicated. CISC is called a complex instruction set computer, which has a huge instruction system, relatively easy programming, advanced instructions and relatively complex CPU design.

5. Cache between CPU and main memory to reduce the speed difference between CPU and memory. Virtual memory is just a logical model of very large memory, not any actual physical memory. It uses auxiliary memory such as disk to expand the main memory capacity and make it used by larger or more programs.

6. Hardware equipment required for interactive processing of multimedia information is based on ordinary PC, including: high-performance CPU (with multimedia extension instruction MMX); Fast large-capacity memory; Sound card; Graphics card; Video card and high quality display; CD-ROM or DVD-ROM drive; Scanner; Digital camera; Peripheral devices such as digital cameras. The software needed for multimedia information processing includes: multimedia operating system; Multimedia creation software and application software, such as image processing, music processing, presentation production, animation production, video processing, etc.

7. The main hardware of microcomputer includes: motherboard, microprocessor, memory stick, graphics card, sound card, network card, external memory, input device and output device. Motherboard is the largest printed circuit board in microcomputer. The motherboard has various interfaces for connecting peripheral circuits and devices, and there are slots for installing CPU, memory, integrated circuit chips, bus interfaces and accessories. The motherboard is installed in the main chassis. Microprocessor consists of controller and arithmetic unit, which are integrated on one chip. It is the core part of the computer, responsible for commanding and controlling other parts to work together and perform various operations on data. The memory stick stores programs and data and is installed on the motherboard. It reads and writes data directly with CPU. The function of the graphics card is to control the display mode of the monitor. Sound card is one of the main components of multimedia computer, which contains the hardware needed for recording and playing sound. A network card is a hardware device that connects a computer and a network. It is connected with network equipment through network cable (or wireless) to realize * * * resource sharing and data exchange. External memory is used to store programs and data that are not running. Input devices mainly refer to keyboards and mice. Keyboard is the most convenient text input tool, mouse belongs to pointing device, and its operation is mainly moving and clicking. Output devices are mainly monitors and printers. The monitor can display the computer output results on the screen, and the printer can print the computer output results on paper.

8. The main technical indicators of hard disk are: hard disk speed, storage capacity, access time, data transmission rate, etc. The hard disk is connected to the host through the system bus, which mainly includes IDE and SCSI.

9. Omit

10.

1 1. Omitted

Fill in the blanks:

1. Memory and external memory; Speed and capacity; Register, cache, memory, external memory

2 supercomputers, mainframes, medium-sized computers, minicomputers, workstations and microcomputers; Processing ability, such as speed, ability, etc.

3. Arithmetic unit and controller; Frequency, word length, floating-point operation ability

4. Frequency

5. Read the data packet, unpack it, pack it and send it.

6. Volatility, RAM, being read out

7. file allocation table

8. 150K

9. Random Access Storage

10. Users and computers

1 1. Universal serial bus

Multiple choice question:

1、B 2、C 3、C 4、BCDEF 5、C 6、B 7、D 8、D 9、D 10、A

1 1、D 12、B 13、D 14、B 15、B

Chapter 4 Core: Operating System

Short answer questions:

1. System software refers to software that manages, monitors and maintains computer hardware and software resources, provides users with a friendly interactive interface, supports users to run application software, and improves the efficiency of computer use. Application software is a variety of programs designed and developed by people to solve some specific problems.

2. The operating system is the system software, the interface between the computer and the user, the effective management and control of the computer software and hardware resources, so that other programs can use the computer software more conveniently and effectively. Operating system can be divided into batch processing system, time-sharing system, real-time system, parallel operating system, network operating system and distributed system.

3. The operating system kernel refers to the kernel of the operating system, which can directly operate various computer resources, realize device driver and manage memory. The shell of the operating system is the interface between the kernel and the user.

4. According to the functional characteristics, the operating system has four functions: process management, memory management, device management and file management.

5. A process is a program that runs in memory. When a job is selected and runs in memory, it becomes a process. Job is the whole process from selecting a program to running to becoming a program. A program is a code compiled by a user to complete a specific task and stored in an external memory. The conversion between them is: the program in the external memory becomes a job after being selected by the OS, and the job runs into a process in the memory after being selected. After the process runs, it becomes a job state and then a program.

6. Process synchronization refers to ensuring that different processes use different resources. Deadlock refers to the fact that processes occupy the resources needed by each other, which makes the processes unable to synchronize.

7. A process is a program that runs in memory, and a thread is usually a smaller basic unit that can run independently than a process. Generally speaking, a program is single-threaded if only one process can handle all tasks; If a program can be decomposed into multiple processes to complete the tasks of the program, then the different processes of program decomposition are called threads.

8. Device independence means that most software has nothing to do with devices. In order to achieve this goal, the modern operating system contains many types of device drivers, so that the operating system can directly support devices.

9. Device driver refers to all program codes related to the device provided by the device manufacturer.

10. The computer clock includes hardware clock and software clock. The hardware clock is a simple crystal oscillator, which directly feeds an electronic counter, sends an interrupt signal to the CPU when the counter returns to zero, and then enters the counting process again. Software clock is timer software, hardware only provides a time interval, and other work is done by software. The role of the clock is to provide system time while preventing the process from monopolizing CPU or other resources.

1 1. Common OS are: MS-DOS: Disk Operating System, which is applied to PC and its compatible computers and adopts command line interface; Windows: a single-user multi-task operating system based on graphical user interface (GUI); Unix: multi-task multi-user time-sharing system; Linux: a free Unix operating system, which can run on a PC and has powerful network functions; Macintosh: the earliest GUI operating system with strong graphics processing ability.

12.Windows has an intuitive and efficient object-oriented graphical user interface, which is used to work in the way of "selecting objects and manipulating objects". Windows, icons, menus, dialogs, etc. Are all Windows objects.

13.BIOS is a basic input and output system, which is a set of programs put in ROM. When the computer starts, the CPU is forced to start execution from this rom. CMOS is a very low-power RAM chip, which is mainly used to store clock data and parameters of various devices. These parameters can be modified by BIOS, so they can't be put in ROM because they need to be modified.

Multiple choice question:

1、B 2、C 3、D 4、D 5、C 6、c8、D 9、B 10、D 1 1、C

Chapter 5 Data Organization and Storage

Short answer questions:

1. data is a set of non-random recognizable symbols representing quantity, behavior and target. Data in a computer is stored electronically, magnetically or optically. The characteristics of computer data are: all data are stored in memory in binary form; Data are organized into "files" according to certain rules, so as to find data quickly and conveniently; Distinguish the nature of data and specify the data as a storage format; Data in a specific format can only be operated by corresponding computer programs; Computer data can be copied and moved; Data can't directly feel its existence, so it must be accessed and processed through special tools. Computer data is also in danger of being lost.

2. Computers store data in the form of files, which are ordered collections of data stored in memory and marked with names. Files can be programs and data executed by computers. A file is an ordered set of information with a file name.

3. The computer organizes data into "files" and stores them in memory. The operating system records whether each cluster on the disk stores data by establishing a file allocation table FAT. When a user opens a file, OS finds the initial cluster of the file from the FAT directory table, locates the location of the file in the FAT table according to the cluster number, finds the cluster used by the file, and writes the data stored in these clusters into memory. The file system mainly solves the problem of accessing files on external storage, and the storage manager will be responsible for data exchange between internal and external storage.

4. The file name is 4. DOS and Windows3. 1: 8 characters, extension: 3 characters, no spaces, no characters/[]; = ""\:, | *>& lt, disallowed file name Aux, Com 1, Com2, Com3, Com4,

Lpt 1，Lpt2，Lpt3，Lpt4，Prn，Nul

File name of Windows 9X/2000/NT/XP: 255 characters, extension: 3~4 characters, spaces are allowed, and characters/[] are not allowed; = ""\:, | *>& lt, disallowed file name Aux, Com 1, Com2, Com3, Com4,

Lpt 1，Lpt2，Lpt3，Lpt4，Prn，Nul

File name of Mac OS: 3 1 characters, with spaces allowed.

File name of UNIX/Linux: 14 ~ 256 characters, spaces are not allowed, and the characters and file names that are not allowed depend on its version.

Common MS file extension:. Exe is an executable file. Com is a command file. Bat is a batch file. Sys is a system file. Dll is a dynamic link library file. Vxd is a virtual device driver. Bak is a backup file. Txt is a text file. Doc is a Word document. Xls is an Excel spreadsheet. C is a c language source program, and. Obj is a target file.

5. The collection of all files in the computer is the file system, which is the organization of management files and file data in the operating system, and the software and managed files and data structures that manage computer software resources in the way of files in the operating system.

6. The organizational form of the document is the logical structure of the document. It studies abstract files in users' minds, and its purpose is to provide users with a clear and easy-to-use logical organization, on which users can store, retrieve and process relevant information. The physical structure of files refers to the storage mode of files in external memory and its relationship with logical structure.

7. The computer file system manages the files in the whole computer according to the "directory". The directory is organized in a directory structure, including a single-level directory structure, a secondary directory structure and a tree directory structure. Windows adopts a tree directory structure.

8. Memory is in the "core position" in the computer, and the relationship between internal and external memory is as follows: when the program is running, the OS transfers the program from external memory (such as disk) to memory; Run in memory, and the data generated by the operation is temporarily stored in memory; After the program runs, the data is saved to the external memory. OS realizes data exchange between internal and external memory through memory manager MMU.

9.FAT refers to the file allocation table. The operating system records whether each cluster on the disk stores data by establishing a file allocation table FAT. NTFS is a new technology file system, which supports FAT and large-capacity disks up to 16EB(264B).

10. There are economic reasons for using the "internal and external" division of memory. Memory: the access speed is nanosecond, and the access price per byte is high; External storage: magnetic technology is used, which is a mechanical movement with slow speed, large capacity and low price. Internal and external memories are complementary in performance and price.

1 1. Memory management dynamically monitors the use of computer storage space. When a program finishes executing, the system will automatically reclaim the memory unit it occupies for other programs to use. Memory management records the memory usage of each program. According to the process, the allocation of memory space is constantly changed, and memory is allocated to the running program.

12. Virtual memory technology is to open up a space larger than memory on the disk, load the executed programs into this area, and organize them according to the structure of memory. Its advantages are: the size of executing program has nothing to do with memory; Mapping technology makes a part of a program load into memory faster.

13. At present, personal computers usually use Intel Pentium processor and Microsoft Windows operating system. In the Pentium system, there is an L 1 cache in the CPU, and the data and program codes are stored separately. L2 cache is managed by CPU, and memory and virtual memory are managed by CPU and MMU of Windows system.

Multiple choice question:

1、A 2、B 3、B 4、C 5、D 6、C

7、C 8、D 9、C 10、C 1 1、B

Fill in the blanks:

1.data

2. Type (reflected by extension)

3. Documentation

4.* 、 ?

5. file system 6. filename

7. folders

8. Graphics, text, execution

9. Switch, disk, disk, request paging, request segmentation, low

Chapter 6 Algorithms, Programs and Design Methods

Short answer questions:

1. In a broad sense, a program is the sum of a series of steps for a computer to perform a certain task operation, and it is an ordered collection of computer instructions. Program design refers to the method and process of designing, compiling and debugging programs.

2. The basic logical structure of the program includes sequence structure, branch structure and loop structure.

Generally speaking, the process of designing a program can be divided into six steps: the definition of the problem or the description of the program; Design solutions to problems; Write program code; Conduct program testing; Documents of the plan; Program application.

4. Object-oriented programming is programming from the perspective of objects, which has the characteristics of encapsulation, inheritance and polymorphism. Common languages are Visual Basic, JAVA, C++ and so on.

5. The main types of programming languages are machine language, assembly language, process-oriented high-level language and object-oriented high-level language.

6. The algorithm of a program can be expressed by natural language, flow chart, structure diagram, pseudo code, PAD diagram and other methods.

7. The characteristics of the algorithm are certainty, finiteness, validity, zero or more inputs and one or more outputs.

begin

Set the initial value of s to 0.

Let the initial value of I be 1.

Set the initial value of the flag to 1.

when I

Let s = s+flag * i.

Let i=i+ 1.

Make a sign =-sign.

(The cycle ends here)

Print out the value of s

end

8. A compilation system is generally composed of several modules: a lexical analyzer, a parser, an intermediate code generator, an optimizer and an object code generator.

9. The format of computer machine instructions is generally: the operand of operation code or the address of the next instruction.

10. Data representation is a symbolic representation of data. Its data structure includes logical structure, storage structure and data operation. According to its structural form, it can also be divided into chain, table, heap, queue and tree. Continuous storage or chain storage can be used in the memory.

1 1. The queue operation is FIFO and the stack operation is LIFO.

12. The structure between data is actually the relationship between data elements, including linear structure, tree structure, graph structure or mesh structure. These structures reflect the logical relationship between data, and are also abstractions of various data in the objective world.

13.ADT is an abstract data type.

ADT S /* defines S as stack abstract data type */

Data elements/* can be of various types belonging to the same data object */

Structure:/* There is a linear relationship between data elements */

Operation:

Null function. Returns "true" if s is empty, otherwise returns "false" */

Full functionality/full functionality. If s is full, return "true", otherwise return "false" */

EnStack(S, x) /* stack function. Insert element x at the top of the s stack. If the S stack is full before insertion, the operation will fail */

Delete stack/* stack function. Delete element x at the top of the s stack and return. If the S stack is empty before deletion, the operation will fail */

Clear /*S stack is empty */

...

14. Software engineering refers to the management of software development as a traditional large-scale project, which contains two meanings: management, supported by necessary theories and methods; Treating software as an engineering has its own characteristics. The software life cycle includes the whole process of determining system requirements, system design, system implementation, system maintenance until the software is no longer used.

Multiple choice question:

1、D 2、D 3、C 4、C 5、A 6、A

Fill in the blanks:

1. sequence, selection (branch), loop

2. When the type and until the type

3. Machine language, assembly language, process-oriented high-level language and object-oriented high-level language; machine language

4. Encapsulation, inheritance and polymorphism

5. Natural language, flow chart, pseudocode

6. Logic (or algorithm), code, documentation, operation and maintenance

7. Understand the problem, design the solution to the problem, implement the solution, and test the solution.

8. Sequence and loop (note that "condition" refers to selection or branching)

9.one-on-one