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[version 2021] all dry goods you have to see if you want to upgrade_ Hematemesis finishing_ Upgraded from college to College_ Fundamentals of Computer Culture (I)

Appreciate meeting Hello I am ken

「 About “ I ”」

First It has to be said that It reopened this time 「 Hematemesis 」 The foundation of computer culture is a series that I first started The old version was " preview " Although very young but I'm still very lucky to get the affirmation and support of some test preparation partners and even in-service teachers This time, I'm going to " Battlefield " Recently, I have read many online classes And the original computer culture foundation higher vocational college special edition preparation Textbook 、 Of multiple sets of test questions " actual combat " Another new edition This time I will use almost harsh requirements Try to organize your layout And focus and Sort out and explain the difficult knowledge points Maybe somewhere you see I have deleted it many times Don't want to mix any nonsense But it also requires complete content In the later stage, the deficiencies of the content will be deleted from time to time

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「 About Analysis of examination papers :」

Chapter title Approximate score
Chapter one Computer culture 18 about
Chapter two operating system 15 about
The third chapter Word 2010 15 about
Chapter four Excel 2010 20 about
The fifth chapter PowerPoint 2010 10 about
Chapter six Access 2010 10 Less than
Chapter vii. computer network 8 about
Chapter viii. Web page creation 2 about
Chapter nine Digital multimedia 5 Less than
Chapter ten Information security 5 about

「 About Chapter one - Computer culture 」

「 」

1.1 Information and Technology

1.1.1 Information and data

Information : In nature , It is common in human society and human thinking activities All matter and things Of attribute .( Judgment questions )

data : Is stored on a medium that can be identified Symbol Information .

Symbol It can be words 、 Letter 、 Numbers 、 graphics 、 Images 、 Audio 、 Video etc. .

The difference and connection between information and data :
The information of Symbolization ( Symbols recognized by computers ) Is the data .
data It's information The concrete form of expression , It's information carrier , and Information is the result of processing data .
Information It is abstracted from the concrete physical form Logical meaning , and Data is the physical representation of information .

1.1.2 information technology

information technology : It means people obtain 、 Storage 、 Pass on 、 Handle 、 Development and utilization information resources Related technology .

1.1.3 The information society

Information society is also called information society
from 20 century 90 s , Major countries in the world began to build high-speed 、 The large capacity 、 Multimedia information transmission trunk line , be called “ information superhighway ”.

1.1.4 The connotation of Computer Culture

⒈ The definition of culture
Culture is a unique phenomenon of human society . That is, the socialization of human behavior , It is the highest and most common social form of human creative function and achievements .
The core of culture : Ideas and values
2. Computer culture
Time :20 century 80 Put forward in the early s
The core : Computer culture That is to say Computer At the core . Set network culture 、 Information culture 、 Multimedia culture as a whole , It also has a wide impact on social life and human behavior 、 A new culture with far-reaching influence
connotation : The real of computer culture connotation It has a computer Information processing Ability .

1.2 Introduction to computer technology

1.2.1 The origin and development of computer

( The probability of taking this test is very low )

The origin of computers
ENIAC The first The real electronic computer is 1946 year 2 Month in The United States The University of Pennsylvania was officially put into operation .
ENIAC use Decimal system
founder : Elan · Turing and feng · Neumann
Turing : Turing machine Computability theory
feng · Neumann : Storage program , Establish the basic structure of modern computer —— feng · Neumann structure

The development of computers

years name Components Language application
The first 1 generation 1946~1956 Electronic tube computer ( Vacuum tube computer ) Electron tube ( Vacuum tube ) machine language 、 assembly language Scientific Computing
The first 2 generation 1956~1964 Transistor computer The transistor High level programming language Data processing
The first 3 generation 1964~1971 Integrated circuit computer Small and medium scale integrated circuits Manipulation system and conversational language Start to apply to all fields
The first 4 generation 1971 year ~ so far VLSI computer vlsi Object oriented high level language Microcomputers have gained popularity , Open the network era

Conclusion of the examination :
⒈ The first generation of electronic computers was designed to be used in the military field
⒉ENIAC Electronic components are tubes , It belongs to the first generation of computers
⒊ The electronic components of modern computers are large-scale and very large-scale integrated circuits , It belongs to the fourth generation computer
⒋1971 year CPU The birth of , It means that computers have entered the fourth generation ( there CPU Microprocessor )

1.2.2 Characteristics and classification of computers ( I love short answer questions here )

  1. The characteristics of computers ( Remember the first three below , Remember the last three bold words )
    1) It's fast : electronic device ( decision )
    2) The calculation accuracy is high : The accuracy of the calculation depends on The word is long ( The computer now has 32 Bit and 64 position , The number of digits here is the word length , The longer the word is , The higher the accuracy )
    3) Large storage capacity : The storage of computer is the difference between computer and other computer tools Important features .
    4) Have the ability of logical judgment : Analyze whether the proposition is true , And we can take corresponding countermeasures according to whether the proposition is established or not .
    5) Work automation : Automatically controlled and executed according to people's pre programmed program .
    6) Strong commonality : Applied in various fields .

  2. The classification of computers
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    Supercomputers
    Supercomputers are also called supercomputers
    It's fast 、 Large storage capacity 、 It is mainly used for Country Safe cutting-edge technology .
    for example :“ Tianhe River ”、“ The Milky Way ”、" dawn " etc. ( All those with names are supercomputers ).
    microcomputer
    abbreviation microcomputer , Also called personal computer (PC、PC machine )
    Development signs :CPU

Conclusion of the examination :
⒈ The earliest computers that used the operating system actually appeared in the second generation , It's just that the textbook says it's the third generation , So when the exam is asked , We should focus on teaching materials .
2. At present, the commonly used computer is digital computer , General purpose computers .
3. According to the scale, it is the most , Among them, supercomputers and microcomputers are the most important , Will take a separate test .
4. Microcomputer is the fourth generation computer , Electronic devices are large-scale and very large-scale integrated circuits .
5. CPU Produced in 1971 year ,CPU Also called central processing unit , This is also called microprocessor . So microcomputers also come from 1971 year .

1.2.3 Computer applications ( Remember the following bold keywords )

( Mainly master the first five , You can understand the last three )

  1. Scientific Computing ( Technology related )
    Also known as Numerical calculation , Mainly involves Complex mathematical problems , It's a computer application Earliest The field of . Mainly used in Cutting edge science field ( Space engineering 、 meteorological 、 The earthquake 、 Nuclear technology 、 Password interpretation, etc ).

Why do you say " Earliest " Well ?
The starting point of computer research is really for military , But the password explanation in parentheses behind the cutting-edge scientific field we mentioned above , It is useful in the military , And after the military, people 、 The country should return to life and development , It will be applied to scientific calculation , Therefore, the earliest field of computer application is scientific computing ( Numerical calculation ).

  1. information management ( Life related )
    Also called Data processing or Transaction processing . Widely used in Office automation 、 Transaction processing 、 Information retrieval 、 Business management and knowledge systems , It's a computer application Most extensive The field of .

  2. process control ( Industry related )
    Also known as real-time control or automatic control , It refers to the control without manual intervention . At present, it has been used in metallurgy 、 oil 、 chemical 、 Spin 、 Water and electricity 、 Machinery and aerospace, etc .

  3. Computer aided system ( All memory , Focus on the key parts in bold )
    CAD —— Computer aided design
    CAM —— Computer aided manufacturing
    CAL —— Computer aided learning ( Also more important )
    CAI —— Cai
    CBE —— Computer aided education
    CMI —— Computer management teaching
    CAT —— Computer aided testing
    CIMS —— Computer integrated manufacturing system

  4. Artificial intelligence (AI)
    The computer simulates the reasoning of the human brain 、 distinguish 、 perception 、 understand 、 Design 、 reflection 、 planning 、 Thinking activities such as learning and problem solving .( Such as robots 、 Expert system, etc )

explain :
robot : The familiar alpha dog 、 Little love students 、siri
Expert systems, e.g : Online consultation , Medical diagnostic system .

  1. Multimedia technology
    It's computer technology 、 The combination of communication technology and audio-visual technology .

  2. computer network
    It is the combination of computer technology and communication technology , Realize mutual communication and resource sharing .

  3. Embedded domain
    For example, digital cameras 、 Automatic washing machine, etc .

Conclusion of the examination :
Mentioned later " In dungeons " Everything belongs to the field of cutting-edge science ( Technology related ), That is, the embodiment of scientific computing in computer application .

1.2.4 The development trend of computer

  • megatrends
  • miniaturization
  • Networking
  • Intelligent

1.3 The representation of information in a computer

1.3.1 The computer uses binary system inside

Why binary ?( Before this part, you often take multiple tests , But now the test probability is small )

  1. Physical devices are easy to implement
  2. The operation rules are simple
  3. It is convenient to realize logical operation
  4. Use fewer devices

1.3.2 Values and their conversion

  1. Various basic concepts
    Number system : Counting with the principle of carry is called carry counting system .( For example, it is often said that two 、 8、 ... and 、 Ten 、 Hexadecimal )
    Digital : A set of symbols used to represent some kind of data .( Binary 0、1 It's digital 0~7 It's an octal number ······)
    base : The number of digits in hexadecimal .( To sum up, the same goes for )
    Position right : The weights of numbers in different positions .( For example, decimal number 234.5,2 The position right of the place is the position right of the hundred, that is 102,3 The weight at is 101,4 The weight at is 100,5 The weight at is 10-1, The weights of binary numbers are 2n, Octal weights are 8n, And so on ······)

Common carry counting system

Base number Digital base Operational rules Representation
Binary system 0~1 2 On the two into one (10)2 perhaps 10B
octal 0~7 8 Every eight enters one. (10)8 perhaps 10Q
Decimal system 0~9 10 Dot into one (10)10 perhaps 10D Or default
Hexadecimal 09,AF 16 Every 16 to one (10)16 perhaps 10H
  1. Numerical transformation

Conversion from non decimal to decimal ( Octal hexadecimal decimal system is the same )

= 1x23+0x22+1x21+1x20+1x2-1 = 11.5

Method :
⒈ Write superscript ( Bits are 0, Increase on the left and decrease on the right )
⒉ Expand according to right
⒊ Multiply and sum

Convert decimal number to non decimal number ( Convert decimal numbers to two 、 8、 ... and 、 Hexadecimal is the same )

Method :
Integral part : Turn and divide I'll take it backwards
The fractional part : Turn a few times a few Press positive to get

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Binary to octal conversion

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Method :
Binary to octal :3 Bit binary representation 1 Bit octal , Let's call it 421 Law
⒈ grouping :3 One by one , Less than three people make up for 0
⒉ Write superscript :421
⒊ Sum within a group
notes : Octal to binary The other way around 421 Law that will do .

④ Binary to hexadecimal conversion
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Method :
Binary to hexadecimal :4 Bit binary representation 1 Bit hex . use 8421 Law
⒈ grouping :4 One by one , Insufficient 4 Place complement 0
⒉ Write superscript :8421
⒊ Sum within a group
Hexadecimal to binary Convert the same octal to binary Reverse 8421 Law

  1. Binary arithmetic operations ( Add, subtract, multiply and divide )

① Binary system - Add

0 + 1 = 1      1 + 1 = 10

② Binary system - Subtraction

Empathy 10-1=1

③ Binary system - Multiplication

④ Binary system - division

notes : Binary multiplication 、 Division and decimal multiplication 、 The division is basically the same Just in addition and subtraction, binary is full two into one .

  1. Binary logic operation

    ① Logic and computation (AND)
    ② Logic or operation (OR)
    ③ Logical non operation (NOT) ( The non operation here should be to add a small bar above the number )
    ④ Logical XOR operation (XOR)
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Example :
Use a hexadecimal number as a 32KB Write address code in memory , Its number shall be from 0000H To (   )H.
Problem solving process and knowledge points involved :
32KB = 235B
End address - The first address +1= Storage size
End address - The first address +1=215
End address - The first address +1=1000 0000 0000 0000 Binary system
End address - The first address +1=8000 Hexadecimal
End address = 8000H - 1 + 0000H( First address ) = 7FFFH

Example :
For one 2KB Storage space , Its address can be 000H To (  )H
2KB = 211B
End address - The first address +1= Storage size
End address = 800H-1+000H = 7FFH

1.3.3 Character and Chinese character coding

  1. Numerical representation

    In the computer , All the data are in the form of Binary system Formal representation of .
    Usually specify a number of highest As Sign bit ,"0" Express positive ,"1" Negative .

Go back and supplement the introduction and exercise of the original code, complement and inverse code

  1. BCD code

    BCD Code belongs to numerical code ( There are many more numerical codes , Like the original 、 repair 、 The inverse is ).
    Each bit of the decimal system is represented by binary code , This coding method is abbreviated as BCD code .

notes :
BCD code It's not binary code
, It's just expressed in binary code , It belongs to a form of expression .( Often take judgment questions )
BCD The first place in the code 0 And the end 0 It can't be omitted .

  1. ASCII code :

    At present, the main character coding is ASCII code ( American standard information exchange code ).ASCII Code is a kind of Western Language Character encoding , Yes 7 position ASCII Code and 8 position ASCII Two sizes .( Seven ASCII Code is a standard ASCII code , It is also the test site in the exam , I didn't say ASCII How many digits is the code , The default is 7 position )

notes :
Although the standard ASCII The size is seven ,1 byte =8 position . however ASCII The code is still "=1 byte ".

( standard )ASCII clock :
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Expand ASCII code (8 position ) surface :
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ASCII Code composition :
( Only the standard ASCII code , common 128 individual )
⒈ Numbers :0 ~ 48,1 ~ 49,···,9 ~ 57; common 10 individual
⒉ Capital :A ~ 65,B ~ 66,···,Z ~ 90; common 26 individual
⒊ Lowercase letters :a ~ 97,b ~ 98,···,z ~ 122; common 26 individual
⒋ Punctuation : common 33 individual
⒌ Control symbol : common 33 individual

notes :
ASCLL Codeco 128 individual , A total of... Can be printed 95 individual
Capital + 32 = Lowercase letters
A lowercase letter > Capitalization > Numbers > Space (32)
Remember the first three , Fourth 、 The fifth is to know how many there are
Be careful standard ASCII Code only includes these five categories , No Chinese characters , It's easy to take a test and choose more . The first three types can be printed , common 95 A printable character . altogether 128 Characters .

  1. Chinese character coding
    ( Remember well )

    GB code :1980 year , China has promulgated the standard of Chinese character coding character set , namely GB2312-80 Information switching The basic set of character sets encoded with Chinese characters 》, The standard code is abbreviated as GB code , It is commonly used in mainland China, Singapore and other overseas Chinese speaking areas Chinese character exchange code .
    ·
    The national standard code consists of Chinese characters + Graphic symbols consist of . Among them, Chinese characters include one level ( frequently-used character ) And secondary ( Rare words are not often used )
    Internal code : Also called internal code . It's inside the computer Storage and handling Chinese characters The code used for information .
    Location code : In order to facilitate query and use , Arrange the national standard codes on one sheet 94 That's ok ( District )94 Column ( position ) In the two-dimensional table of . such Area code and tag number Each use 2 position Decimal number It forms the location code of Chinese characters .

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Pithy formula : District ( Long )( Out ) countries ( Sit and fly ) machine

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  1. Chinese character font library : It is the graphic data needed to display Chinese characters on the screen or print them on paper .

    Chinese character font code records the shape of Chinese characters , It is the output form of Chinese characters . There are usually two ways to record Chinese characters : Dot matrix method and vector method .
    All the different Fonts 、 The Chinese character font of the font size constitutes the Chinese character library .
    The storage space occupied by storing a Chinese character font Number of bytes The calculation method of : Line points * Column points /8( This product is a lattice ,8X8、16X16、32X32··· And 1 Bytes are 1B)

Example :
One 16* 16 The space occupied by dot matrix Chinese characters is 16*16/8=32B

  1. Chinese character input code :

    Pipelined code : Telegraph code 、 Location code
    sound-based input code : full pinyin 、 Double spelling 、 Microsoft Pinyin
    Shape code : Five strokes
    Sound shape combination code : Nature code
    ( The middle two above did a little more , The other two did less , And the overall test is less )

notes :
Storing a Chinese character takes up two bytes , Storing an English character takes up one byte

「 About Nagging 」

Recently, I rent a house alone and study for the exam by myself. I really realized the taste of loneliness in my life That feeling is You are also mixed with some students' vision of beautiful ideals 、 They also have their own understanding of society 、 But I haven't really understood the so-called adult's world , At that time All you've endured 、 Things that have not been borne will flock to That sense of oppression Makes me this time Try hard 、 Worked hard 、 Indulgence 、 Also collapsed Fortunately, I have been confused, but I have never given up Sometimes I think Similar to me 、 Millions of those people Come with me, too Hold the line

「 Private letters prefer to chat on wechat Encourage each other to learn from each other during the reception and preparation You can add my wechat below The circle of friends will share the update reminder of this series of articles 」

Appreciate meeting I am ken

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