Happy New Year, everybody. I’m your cat brother. I’m back

I believe everyone had a happy New Year

Have fun and start learning

preface

As a so-called computer training background of the people, particularly embarrassed is that their computer foundation is very poor, I believe this is not a few programmers status quo, but the vast majority of programmers status quo.

For example, the computer network almost failed that year, thanks to the mercy of the teacher at the time, I just gave a passing grade.

But after cat brother came out to work, he especially felt that the students’ computer foundation was very poor, mainly because of the problems of teachers and educational resources. The teachers all talked according to books or PPT, which was very boring.

If there are good learning resources, it can definitely stimulate the interest of learning, or it can be easier to learn, not so difficult.

The longer I have been working as a programmer, the more I seem to understand the importance of these basic knowledge and principles. It is simple to say this, but the boredom of it makes a lot of students who are eager to get frustrated. They all say that interest is the most important, how to boost this interest.

Recently, Cat brother happened to find such a course when visiting b station, through graphic and vivid introduction of the basic knowledge of computer, watched a few episodes, feel very good, specially recommend this “Crash Course in Computer Science” to everyone.

Crash course in computer science

This 40-episode course really covers a lot of the basics:

The first1Set: Equipment mentioned in the early history of computers: the abacus → the stepping calculator → the difference engine → the analytical engine → the punch card tabulating machine02:27The earliest computing device was the abacus04:31Computer changed from referring to a profession to referring to a machine04:57The machine is known as the stepping calculator. The first machine that could add, subtract, multiply and divide06:44Shells for accuracy, to calculate the trajectory, world War II was done by looking up tables. But every time you change the design, you have to make a new table07:30Charles Babbage"Difference engine"During the construction of the difference engine came up with the analytical engine which is a general purpose computer08:50Lovelace wrote a hypothetical program for the analytical machine, thus becoming the first programmer09:25The census10Once a year. Herman Hollerith's punch card tabulating machine greatly improved efficiency2Set: electronic computer mentioned equipment: relays → vacuum tubes → transistors00:17 20The development of the century calls for more computing power. A computer the size of a cabinet grew to the size of a room01:06The harvard Mark1IBM, number,1944In doing02:25Relays, relays in one second at most50Time to switch03:24Relay bug03:49 1904The thermionic tube appeared, the first vacuum tube. Improved to function like a relay05:34 Giant one.The first large-scale use of vacuum tubes in computers was at Bletchley Park in England. But the programming is troublesome, and the configuration is necessary06:40 1946The ENIAC at the University of Pennsylvania was the first general-purpose programmable computer07:36 1947In 2005, Bell LABS made the transistor, the transistor has many benefits, IBM soon fully transitioned to the transistor09:27A Silicon Valley reference: Much of the development of transistors and semiconductors was done here. The most common material used to make semiconductors is silicon09:41Shockley Semiconductor → Fairchild Semiconductor → Intel No3Set: Boolean logic and logic gates01:00What is binary and why do we use binary Boolean logic02:46 3Basic operations: NOT, AND, OR02:51explain3Basic operations07:11XOR (exclusive or first4Set: binary00:46Use the decimal system as an example to demonstrate binary addition. Storage Unit: MB GB TB05:30Positive, negative, integer, floating point representation07:20American Standard Code for Information Exchange - ASCII, used to represent characters09:00 UNICODE 1992It is a character coding standard, which solves the problem that ASCII is not enough to express all languages5Set: Arithmetic logic unit - ALU00:03A brief introduction to ALU, Intel74181
01:24The ALU is2A unit,1Sum of arithmetic units1Logical unit01:32Arithmetic unit half adder (processing1A bit,2Full adder (processing1A bit,3An input)8Bit addition (1Half adder,7The concept of overflow, pac-Man's example of multiplication and division07:32The logical unit detects whether the number is0ALU is abstracted into a V symbol Flag (whether equal, whether less than, whether overflow, etc.)6Set: Registers and Memory03:30 存 1Bit (Gated Latch)04:48 存 8Bits (Register - Register)05:46The 16x16 matrix store256Multiplexer bit data selector/Multiplexer decoding8Bit address to locate to a single latch07:38 4A bit represents a row,4A representative column08:16combination256Bit memory + multiplexer09:01addressable256Byte memory one1980Age memory, 1M size10:14 8Modules. Each module has32It's a little square. Each square has4It's a little piece, and each little piece is128An x64A first7Set: Central processing unit (CPU) focus on a CPU out of the CPU how to execute commands01:00RAM + register + ALU for a CPU04:00explain"Fetch instruction → interpret → execute"The cycle08:00What is a clock, clock speed and Hertz10:00Overclocking improves performance, reduces frequency and saves power8Set: instructions and procedures this set focus: take you step by step to run a program00:45Let's review the example program from the last video, step by step. This section describes the concept of instruction set, such as the LOAD_A, LOAD_B, SUB, JUMP, ADD, and HALT commands05:16Conditional JUMP, JUMP NEGATIVE is NEGATIVE, and there are other types of JUMP08:00Truly modern cpus use more instruction sets. The digits are longer.09:07 1971Intel 20004004Processor, yes46An instruction09:36Now the Intel Core I7 has thousands of instructions9Set: Advanced CPU design00:24Early on it was to speed up transistor switching to increase CPU speed01:20Give the CPU dedicated division circuit + other circuits to do complex operations, such as games, video decoding02:28Add cache to THE CPU, improve data access speed, faster feed to the CPU, using the calculation of restaurant sales as an example05:13Dirty bit - Dirty bit05:33Assembly line design, with1A washing machine and1A dryer for example06:01Parallel processing - parallelize07:33The command is executed out of order. -out -of-order execution
08:21Speculative execution08:50Branch prediction09:34Multiple ALU09:54Multi-core (Core)10:11Multiple independent cpus10:52Supercomputer, Chinese"Sunway Taihu Light"

第 10How did early computers program punch paper cards00:00How does a program enter a computer00:53In the textile industry, for example, the need to program machines predates the advent of computers01:41Punch paper card - Punched card02:36A Plugboard04:20Von Neumann Architecture07:00Panel programming - Panel programming07:29The first commercially successful home computer: the Altair8800
08:15Programming is still hard, and people need friendlier and simpler ways to program08:44Next week's topic: Programming Languages No11Set: Programming language history Programming: binary → mnemonic (assembler) → A-0(compiler) → FORTRAIN01:45Binary write program, first write pseudo code on paper, manual transfer binary, soon tired02:28 用 To convert the mnemonic to binary, Grace Hopper -- one of the first programmers on the Harvard 1 computer, Navy officer 05:13 Grace designed the programming language A-0 05:29 Grace made the first Compiler in 1952, New languages 1960s: ALGOL, LISP, BASIC 1970s: 1980s: C++, Objective-C, Perl 1990s: Python, Ruby, Java Programming Basics - Statements and functions 00:50 Variables, Assignment statement 02:08 Grace Hopper shoot insect game 02:52 if judge 04:19 while loop 05:48 for loop 07:00 Function 11:11 Merge sort 08:03 Dijkstra algorithm 第 14 集 : Merge sort Data structure 00:39 Array-array 02:06 String - String 03:12 Matrix-matrix 04:05 Struct 04:46 Pointer - Pointer 04:44 Node - Node 04:53 Linked List 06:21 Queue 06:21 Stack-stack 07:31 Tree 08:01 Binary Tree 08:26 Graph 08:50 No time for red-black trees and heaps, different data structures for different scenarios Alan Turing 00:33 Introducing Alan Turing 00:52 Decidable Question 01:14 Alonzo Church, Lambda Operator 01:38 Turing Machine 04:54 Down problem 08:09 Cracking the German Enigma 10:40 Turing Test 11:18 Turing's personal Life 12:07 Turing Awards Episode 16: Object Oriented Programming. 03:55 API Application Programming Interface 04:33 public Private 05:36 IDE - Integrated Development Environments 06:09 Debugging 06:31 Comment 07:33 Version Control 08:50 Quality Assurance Testing, QA 09:21 Beta, Alpha 第 17 集 : Integrated Circuits and Moore's Law Wafer fabrication process: Tyranny of Numbers - a problem engineers had in the 1960s, which meant that if you wanted to make a computer more powerful, you needed more parts, This leads to more circuits, more complexity. So it's hard to do 04:21 Photolithography 04:26 Wafer Wafer 04:57 Photoresist 05:08 Photomask 06:00 Doping 09:09 Moore's Law The number of transistors increased dramatically, 30,000 in 1980, 1 million in 1990, 30 million in 2000, and 1 billion in 2010. 11:44 Further miniaturization poses two problems. The wavelengths of light are not enough to make more elaborate designs. Computers became cheaper and more numerous, there were different configurations, and it was painful to write programs to handle the details of different hardware. So the operating system is responsible for abstracting the hardware 02:12 Peripherals 02:48 Device drivers 04:43 Multitasking In the 1970s, computers were cheap enough for universities to buy them for students to use, and multiple students to use multiple."terminal"Connect to host 08:29 Multi-user Time-sharing operating system, Multics 09:32 Unix 11:02 MS-DOS 12:09 Delay Line Memory 04:06 Magnetic Core Memory 06:08 Magnetic Tape 07:08 Magnetic Drum Memory 07:43 Hard Disk Drives 08:53 Memory Hierarchy 09:36 Floppy Disk 10:09 Floppy Disk Compact Disk 10:51 Solid State Drives 00:47 Compact Disk 10:51 Solid State Drives 00:47 ASCII 01:31 WAV Audio file: thousands of audio samples per second Number 02:47 BMP image file: pixel red, green and blue RGB values 04:43 File system: Very early space is small, the entire memory is like an entire file. Directory files: Used to solve multiple File problems, storing information about other files, such as beginning, end, creation time, etc. Files are all in the same level, early space is small, only a dozen files, flat system is enough 06:57 If the files are closely sorted one by one, it will cause problems, so the file system will: 1. Partition the space into blocks 2. Files are split into multiple blocks. 08:30 The addition, deletion, modification and examination of files will inevitably cause files to be scattered in various blocks. 09:46 Hierarchical File System: there are different folders, folders can be nested layer by layer The good thing about compression is that you can save more files, Huffman Tree 05:56 "Huffman Tree 05:56"Eliminate redundant"And"Let's do it in a more compact way", These two methods are usually combined to use 06:07 Dictionary coders, Perceptual coding 08:09 Lossless compression JPEG format 09:39 Temporal redundancy 10:30 MPEG-4 Video coding Set: Command line interface In the early days of computers, they fed programs and data simultaneously (using paper cards/tape) and ran them from start to finish without a human in between. The reason was that computers were too expensive to wait for humans to input them slowly and then print the results on paper (02:34). By the 1950s, computers were cheap enough and fast enough. It became possible for humans and computers to interact with each other in order for humans to input into the computer, the typewriter that had existed before was transformed into a teletype (02:44~05:38). By the end of the 1970s, the screen cost was low enough that the screen replaced the teletype, In the early days, output data was printed on paper, and input was used to use paper cards/tape to feed the program and data in at once. Invented by Christopher Latham Sholes in 1868 05:38 Teletype machine 06:32 LS 08:22 Early word game Zork (1977) 08:47 CD Command 23: Screen with 2D Graphics Display 00:05 PDP-1 computer. The keyboard and the monitor are separate, and the screen displays a temporary value Liquid Crystal Displays (LCD) Pixel 03:32 Character Generator 03:45 Screen Buffer 05:09 Vector Command Drawing 06:34 Sketchpad The Cold War and Consumerism Van Neva Bush foressaw the potential of computers and proposed a hypothetical machine called Memex. He helped establish the National Science Foundation to fund scientific research. In the 1950s consumers began to buy transistor devices. The Soviet Union sent The cosmonaut Gagarin into space in 1961, which led to the United States proposing to go to the moon and a huge increase in NASA's budget. The development of integrated circuits was actually greatly advanced by military applications. After all, the Apollo moon landings were only 17 times. The U.S. built supercomputers further advanced integrated circuits. Ignoring the consumer market, the cold War faded in the 1970s and the industry began to decline. Many companies went out of business and Intel turned to processors. Government and consumers drove the development of computing in the early years with government money to get the technology developed enough for commercial use, and then consumers to buy commercial products and continue to drive product development. It's all history 00:1870s when costs fall and personal computers become available 01:51 Altair 8800 02:32 Bill Gates and Paul Allen write BASIC interpreters 03:45 Jobs proposes selling assembled computers, In 1977, there were three out-of-the-box computers:Apple-II"，"TRS-80 Model I"，"Commodore PET 2001"06:26 IBM realized that the PERSONAL computer market, the IBM PC release, with an open architecture, Compatible machines called IBM Compatible ecosystem, had a snowball effect: Because there are so many users, the hardware and software developers are more likely to invest in the platform and the users are more likely to buy it."IBM compatible"The computer 08:44 Apple chose the closed architecture, everything comes by itself, only Apple in non"IBM compatible"Below maintains enough market share in Episode 26: Graphical User Interface (GUI) 01:10 GRAPHICAL Interface Pioneer: Douglas Engelbart founded Palo Alto Research Center 03:20 in 1970 and completed the Xerox Alto(Xerox Otto) computer in 1973 04:42 example: Write a simple GUI program 06:38 The Xerox Star System of 1981 08:18 Steve Jobs visits Xerox 07:45 what you see is what you get WYSIWYG 09:15 The Apple Lisa is introduced in 1983 10:12 Windows 1.0 was introduced in 1985. In 1995, Windows 95 was introduced to provide a graphical interface. In 1995, Microsoft failed to do Microsoft Bob. Wireframe Rendering 01:39 Orthographic Projection 01:50 Perspective Projection 02:14 Mesh Triangles are more common because they can define a unique plane Buffering 07:45 Z Fighting error 07:51 Back Face Culling Surface Normal Shading Gouraud shading, Phong shading 10:06 shading Texture Mapping 11:24 GPU, Graphics Processing Unit 第 28 集 : Computer network 02:05 Local Area Networks-LAN 02:36 Media Access Control Address-MAC 02:55 Carrier Sense Multiple Access - CSMA 05:18: Exponential Backoff 05:36 Collision Domain Circuit Switching 07:36 Packet Switching 10:20 Packet Switching Internet 02:23 IP - Internet Protocol - Internet Protocol 03:00 UDP - User Datagram Protocol 03:41 Checksum - Checksum 05:26 TCP - Transmission Control Protocol 08:21 DNS - Domain Name System - Domain Name System 10:47 OSI - Open System Reference model - Open System Interconnection Episode 30: World Wide Web 01:01 Hyperlinks 02:20 URL - Uniform Resource Locator 03:01 HTTP - HyperText Transfer Protocol 04:13 HTML - HyperText Markup Language 04:24 
  
 
         
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    1.  The World Wide Web was born 07:19 Start telling the story of search engines 07:40 Jerry and David's guide to the World Wide Web was later renamed Yahoo 07:52 JumpStation 09:07 Google 09:20 Net neutrality Number one 31 sets: Secrecy, Integrity, Availability 01:49 Threat Model 03:14 There are three ways of Authentication: 07:34 Access Control 08:48 Bell LaPadula model can't read up, Cannot write down 11:00 Isolation Sandbox 第 32: Social Engineering 01:38 Phishing 02:06 Pretexting 02:50 Trojan Horses 03:32 NAND Mirroring 04:12 Exploit 04:16 Buffer Overflow Buffer Overflow 05:45 Bounds Checking 06:16 Code Injection 09:32 zero day Zero Day Vulnerability 09:53 Worms 09:58 Botnet 10:11 Encryption 00:16 Multi-layer Defence in depth 01:00 Encryption Decryption - Decryption 01:11 Caesar cipher 01:27 Substitution cipher 01:59 Permutation cipher 02:03 Columnar transposition cipher 02:37
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Data encryption standard"- Data Encryption Standard (DES) 05:24 2001年"Advanced Encryption Standard- Advanced Encryption Standard (AES) 07:06 - Key Exchange 07:33One-way function"And"Key encryptionRSA Key Exchange 10:18 Asymmetric encryption 11:22 Asymmetric encryption Machine Learning and ARTIFICIAL Intelligence 01:23 Classification 01:25 Classifier 01:34 Feature Feature 02:03 Labeled data 02:38 Decision boundary Decision The boundaries 03:00 Confusion matrix 03:39 Unlabeled data 03:49 Decision tree 04:25 Support Vector machine Machines 05:52 Artificial Neural Network 08:34 Deep learning 09:21 Narrow AI 09:43 Strong AI 10:42 Reinforcement Learning Computer vision 02:41 Algorithm for Detecting vertical edges 03:26 Kernel or filter 03:56 Convolution 04:23 Prewitt Operators 05:34 Viola Jones After the Face is recognized, other algorithms can be used to locate facial marks, such as the specific locations of eyes and eyebrows. Track marks all over your body, such as your shoulders, arms, etc. Phrase structure rules 02:32 Parse tree 05:30 Speech recognition Spectrogram: Spectrogram; Fast Fourier Transform: Phonemes; Speech Synthesis; The first computer-controlled machines came out in the late 1940s, In 1960, Unimate, The first commercially sold programmable industrial robot simple control loop 04:08 Negative feedback loop 05:17 Proportional integral-differential controller 10:48 Three Laws of Robotics 分 钟 : Proportional -- Integral -- Derivative Controller Computer Psychology 00:45 We need to understand human psychology to make better computers Phone number: 317-555-3897 vs. 3175553897 Easy to remember 03:25 Intuitive features - Affordances 04:33 RECOGNIZE vs Recall Vs Recognize 05:45 Gives the machine some emotional intelligence as well Facebook's study 08:40 uses software to correct fixation positions. Making video calls look like they're staring at each other, not staring down 09:58 Making robots look like people, Uncanny Valley theory 11:35 There's a lot of open questions, psychology helps us understand the impact of different choices By adjusting the speed, pausing, etc., 03:15 Massive Open Online Courses (MOOC) 05:08 Intelligent Tutoring Systems 05:22 Determination rules - Production rule 06:10 Domain Model 06:46 Students have learned the probability of a shot in the dark the probability of error the probability of learning in the process of doing the problem Educational Data Mining (end) 第 40 episode: The Singularity divides work into four quadrants and discusses the impact of automation Can explore the universe for a long timeCopy the code

You think you’re done here? No! How can this be!

The translators have also thoughtfully included a summary of the opening credits at the beginning of each episode, so you know what the episode is about right from the start.

Which time point told what knowledge point, is really close fried chicken!

Such a thoughtful translation team produced such a conscientious course.

Really strongly suggest that we must have a good look, sink down, seriously learn a little every day, when compound interest inflection point, one day you will have an Epiphany, and advance by leaps and leaps.

Address of Station B:

www.bilibili.com/video/av213…

Making address:

Github.com/1c7/Crash-C…

If you want to download this course, please follow this official account, wechat search “front-end GitHub”, reply to the computer, you can get the download link, reply to “e-book” you can get 160 front-end essence books oh.

Before also wrote similar: recommend 7 Github nearly 200K Star computer learning resources, practice good inside the secret book! I believe you will find the treasure!

The last

Between the primary front end and the advanced front end, a big reason is the difference in the time and experience invested in the learning front end, in fact, is the information gap.

If there is a place to get good front-end information quickly and well, it will greatly reduce the time to go from beginner to advanced.

Front-end GitHub is one such repository that can help front-end developers save time!

Public account: front-end GitHub, focused on mining good front-end open source projects, smoothing out your front-end information asymmetry.

I have recommended nearly 200 excellent projects on topics such as interview projects, CSS quirks, Code specifications, data structures and algorithms, JavaScript quirks, and front-end essential online tools.

How to find a good open source project? Check out this article: GitHub Mining Tips – How to Find a Good Open source Project

For more on Cat brother, you can read my year-end review: Front-end Engineers 2020 Year-end Review – The World is still up in the air, you and I are both dark horses

Imperceptibly, has already written the 19th, past period fine article please look below treasure storehouse, please carefully enter!

Github.com/FrontEndGit…

Past pure text

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