Start from typing and understanding the Internet. You can buy books and give you some introduction: Name: Computer
The scientific name of computer is electronic computer, which was developed from early electric calculators. of.
When it comes to "the world's recognized first electronic digital computer", most people think of it as the "ENIAC" that was launched in 1946. It was mainly used to calculate ballistics. It was manufactured by the Moore School of Electrical Engineering at the University of Pennsylvania, but it is huge, covering an area of ??more than 170 square meters, weighing about 30 tons, and consuming nearly 100 kilowatts of electricity. Obviously, such computers are very expensive and inconvenient to use. This statement is commonly used in basic computer textbooks. In fact, according to the ruling of the U.S. Supreme Court in 1973, the earliest electronic digital computer should be John Atanasoff, associate professor of the Department of Physics at the University of Iowa, and his graduate assistant. "ABC" (Atanasoff-Berry-Computer) manufactured by Clifford E. Berry (1818-1963) in October 1939. The reason for this misunderstanding is that a person named Moakley in the "ENIAC" research team plagiarized the research results of John Atanasoff in 1941 and applied for a patent in 1946. For various reasons, this mistake was not reversed until 1973. Later, in order to commend and commemorate John Atanasoff's great contributions in the field of computers, in 1990, former U.S. President Bush awarded John Atanasoff the nation's highest technology award, the "National Science and Technology Award."
In 1956, the transistor electronic computer was born. This is the second generation of electronic computers. Just a few larger cabinets can accommodate it, and the computing speed is greatly improved. In 1959, the third generation of integrated circuit computers appeared.
The original computer was invented by John von Neumann (the computing power of the computer at that time was equivalent to the current calculator), which was as big as three warehouses, and was gradually developed.
Starting in the 1970s, this is the latest stage of computer development. By 1976, the "Clay 1", made of large-scale integrated circuits and very large-scale integrated circuits, brought computers into the fourth generation. The invention of very large-scale integrated circuits has enabled electronic computers to continue to be updated in the direction of miniaturization, miniaturization, low power consumption, intelligence, and systematization.
In the 1990s, computers developed in the direction of "intelligence", creating computers similar to the human brain that can perform tasks such as thinking, learning, memory, and network communication.
Entering the 21st century, computers have become notebook-sized, miniaturized and specialized, with operation speeds exceeding 1 million times per second. They are not only easy to operate and cheap, but can also replace part of people's mental work, even in Some aspects extend human intelligence. Therefore, today's microelectronic computers are vividly called computers.
The world's first personal computer was launched by IBM in 1980. IBM launched a personal computer based on Intel's x86 hardware architecture and Microsoft's MS-DOS operating system, and formulated PC/AT specifications for PCs. The subsequent development of microprocessors launched by Intel and operating systems launched by Microsoft is almost equivalent to the development history of personal computers. The Wintel architecture has completely replaced IBM's dominant position in personal computers.
[Edit this paragraph] Classification
There are many classifications of computers based on their type, operation mode, components, operating principles, application status, etc.
In terms of data representation, computers can be divided into three categories: digital computers, analog computers and hybrid computers;
Digital computers are divided according to the components they constitute. There were mechanical computers and electromechanical computers. , currently used electronic computers, optical computers, quantum computers, biological computers, neural computers, etc. that are under research.
Electronic computers can be divided into giant, large, medium, small, microcomputers and microcontrollers in terms of their scale or system functions.
[Edit this paragraph] Composition
No matter what kind of computer, they are composed of hardware and software, and the two are inseparable. A computer without any software installed is called a bare metal computer.
Hardware
The electronic circuits and physical devices used in computer systems are visible and tangible entities, such as central processing unit (CPU), memory, and peripheral devices. (Input and output devices, I/O devices) and buses, etc.
① Memory. The main function is to store programs and data. Programs are the basis for computer operations, and data are the objects of computer operations. Memory is composed of memory bank, address decoder, read and write control circuit, address bus and data bus. The memory that can directly and randomly access instructions and data by the central processor is called main memory, and large-capacity memories such as magnetic disks, tapes, and optical disks are called external memory (or auxiliary memory). The computer storage system consists of main memory, external memory and corresponding software.
②The main function of the central processing unit is to execute the operations specified by the program one by one according to the program stored in the memory. The main components of the central processing unit are: data register, instruction register, instruction decoder, arithmetic logic unit, operation controller, program counter (instruction address counter), address register, etc.
③External devices are the bridge between users and machines. The task of the input device is to convert various forms of information such as data, characters, text, graphics and programs that the user requires the computer to process into a coded form acceptable to the computer and store them in the computer. The task of the output device is to output the computer processing results in the form required by the user (such as screen display, text printing, graphics, language and audio, etc.). The input and output interface is a buffer device between external devices and the central processor, responsible for matching electrical performance and converting information formats.
Software
A general term for a collection of programs that enable a computer hardware system to work smoothly and efficiently. Programs are always stored and represented through some kind of physical media, such as disks, tapes, program paper, punched cards, etc. But software does not refer to these physical media, but to the invisible and intangible programs themselves. Reliable computer hardware is like a person's strong body, and effective software is like a person's smart thinking.
The computer software system can be divided into two parts: system software and application software. System software is responsible for the management, scheduling, monitoring and services of the entire computer system resources. Application software refers to various applications developed by users in various fields for their own needs. Computer software systems include:
① Operating system: the core of system software, which is responsible for the management, control and monitoring of various soft and hard resources in the computer system.
②Database management system: Responsible for the management and sharing of all files, information and data in the computer system.
③Compilation system: Responsible for compiling source programs written by users in high-level languages ??into machine language that the machine can understand and execute.
④Network system: Responsible for organizing and managing the network resources of the computer system, enabling mutual resource sharing and communication between multiple independent computers.
⑤ Standard program library: A collection of programs written in a standard format. These standard programs include calculation programs for solving elementary functions, linear equations, ordinary differential equations, numerical integration, etc.
⑥Service program: also called utility program. Various programs provided to enhance the service functions of computer systems, including the installation, connection, editing, error checking, error correction, diagnosis and other functions of user programs.
In order to make computers calculate quickly and accurately, and remember more and more firmly, many improvements have been made over the past decades to increase the processing speed and accuracy of the central processing unit in a single machine, and to increase the access speed and capacity of the memory, such as: increasing the number of calculations The basic word length of the processor and improve the accuracy of the arithmetic unit; add new data types, or customize the data so that the data has identifiers to distinguish instructions and numbers, and describe the data type; add general-purpose registers in the CPU , using index registers, adding indirect addressing functions and adding cache memory and using stack technology; using memory interleaving technology and virtual memory technology; using instruction pipelines and operation pipelines; using multiple functional components and adding co-processors, etc. .
Compared with electronic computers, photonic computers have the following main advantages:
(1) Ultra-high-speed computing speed. Photonic computers have strong parallel processing capabilities and therefore have higher computing speeds. The propagation speed of electrons is 593km/s, while the propagation speed of photons reaches 3×10?5km/s. For electronic computers, electrons are the carrier of information. They can only be conducted through some mutually insulated wires. Even in Under the best circumstances, the speed of electrons in solids is far slower than the speed of light. Although the computing speed of current electronic computers continues to increase, its capability limit is still limited; in addition, as the assembly density continues to increase, it will The electromagnetic interaction between conductors continues to increase, and the heat emitted is also gradually increasing, thus restricting the operating speed of electronic computers; photonic computers operate much faster than electronic computers, and their requirements for environmental conditions are also higher than those of electronic computers. Much lower.
(2) Ultra-large information storage capacity. Compared with electronic computers, photonic computers have ultra-large information storage capacity. Photonic computers have an extremely ideal light radiation source - lasers. The conduction of photons does not require wires, and even if they intersect, there will be no interaction between them. The density of the parallel channels through which photonic computers transmit information without wires is actually infinite. A mirror the size of a nickel can carry information many times as much as the existing telephone cable channels around the world.
(3) It consumes little energy and dissipates low heat. It is an energy-saving product. The drive of a photonic computer only requires a small part of the drive energy of an electronic computer of similar specifications. This not only reduces the power consumption and greatly reduces the heat emitted by the machine, but also provides convenience for the miniaturization and portability of photonic computers. condition. Scientists are experimenting with combining traditional electronic converters with photons to create a "hybrid" computer that can process information faster while overcoming the internal overheating problems of giant electronic computers.
At present, many key technologies of photonic computers, such as optical storage technology, optical interconnection technology, optoelectronic integrated circuits, etc., have achieved breakthroughs. Maximizing the computing power of photonic computers is what current scientific research is facing. tackle key issues. The advent and further development and improvement of photonic computers will provide infinite power for mankind to move towards a better tomorrow.
Hybrid computer
Hybrid computer is a computer system that can process digital information and simulate physical quantities. Hybrid computers connect digital computers and analog computers together through digital-to-analog converters and analog-to-digital converters to form a complete hybrid computer system. Hybrid computers generally consist of three parts: digital computers, analog computers, and hybrid interfaces. The analog computer part is responsible for fast calculations, while the digital computer part is responsible for high-precision operations and data processing. Hybrid computers have the characteristics of both digital computers and analog computers: fast operation speed, high calculation accuracy, strong logic and storage capabilities, large storage capacity and strong simulation capabilities. With the continuous development of electronic technology, hybrid computers are mainly used in real-time complex large systems such as aerospace and missile systems.
When operating on a hybrid computer, analog variables from the analog computer are converted into digital variables via an analog-to-digital converter and sent to the digital computer. At the same time, the digital variables from the digital computer are converted into analog signals through the digital-to-analog converter and sent to the analog computer. In addition to the conversion and transmission of calculation variables, there is also the transmission of logic signals and control signals. Analog computers used to perform parallel operations and digital computers used for serial operations are synchronized in time. Every time the digital computer completes a frame of calculation, it exchanges information with the analog computer and corrects the data once. During the time interval (frame) between the two information exchanges, both computers use the calculation result of the previous frame as the initial value to perform calculations. This time interval is called the frame synchronization time. The design of hybrid programs requires users to consider the distribution of models on different computers, the choice of frame synchronization time, and the understanding of the hardware characteristics of the connected system.
Modern hybrid computers have evolved into hybrid multiprocessor systems with the ability to automatically orchestrate simulation programs. It includes an ultra-small computer, one or two peripheral array processors, and several analog processors with automatic programming capabilities; between various processors, a hybrid intelligent interface is used to complete the conversion and transmission of data and control signals. This system has strong real-time simulation capabilities, but is expensive.
Intelligent computers
Intelligent computers (intelligent computers) have no generally accepted definition so far. A. Turing, one of the founders of computing theory, defined computers as digital computers that process discrete amounts of information. There are diametrically opposed views on the principle issue of whether digital computers can simulate human intelligence. In 1937, A. Church and Turing independently proposed the hypothesis that human thinking ability is equivalent to the ability of recursive functions. This unproven hypothesis was later expressed by some artificial intelligence scholars as: If a problem that can be submitted to a Turing machine cannot be solved by a Turing machine, then the problem cannot be solved by human thinking. This school of thought inherits the philosophical tradition of rationalism and reductionism, which is dominated by logical thinking, and emphasizes the great potential of digital computers to simulate human thinking. Other scholars, such as H. Dreyfus and other philosophers, firmly believe that digital computers based on Turing machines cannot simulate human intelligence. They believe that digital computers can only do formal information processing, but human intellectual activities may not necessarily be formalized, nor may they be information processing. Human intelligence cannot be regarded as governed by discrete, deterministic rules that have nothing to do with environmental situations. operation. In principle, this school of thought does not deny the possibility of constructing an intelligent machine with materials close to the human brain, but this broad intelligent machine is different from a digital computer. Some scholars believe that no machine can simulate human intelligence, but more scholars believe that most activities in the brain can be analyzed using symbols and calculations. It must be pointed out that people's understanding of computing is constantly deepening and broadening. Some scholars regard all physical processes that can be realized as computational processes. Genes can also be viewed as switches, and the operations of a cell can also be explained using calculations, the so-called molecular computing. In this sense, the broad category of intelligent computers is almost the same as intelligent machines or smart machines.
Single-chip computer
Single-chip computer refers to a microcomputer in which the main components of the computer are made on an integrated chip. Single-chip computers are also called single-chip computers or microcontrollers. Starting in the 1970s, 4-bit single-chip computers and 8-bit single-chip computers appeared. In the 1980s, 16-bit single-chip computers appeared, and their performance was greatly improved. 20 In the 1990s, 32-bit microcontrollers and microcontrollers using FLASH storage appeared. Due to the high degree of integration of single-chip computers, single-chip computers have the advantages of small size, low power consumption, strong control functions, flexible expansion, miniaturization and ease of use. They are widely used in the manufacturing of intelligent instruments and applications through the construction of application systems. Industrial control, manufacturing of household smart appliances, use of network communication equipment and medical and health industries.
[Edit this paragraph] Precautions for using computers
1. Switching on and off:
Computer equipment must be powered off correctly, otherwise its working life will be affected. It is also the culprit of some malfunctions.
The correct sequence of turning on and off a computer is: to turn on the computer, first connect and turn on the power of the computer's peripheral devices (such as monitors, printers, etc.), then turn on the power of the computer host; shut down The order is exactly the opposite, first turn off the power of the host, and then disconnect the power of other peripheral devices.
2. Safety instructions for using computer equipment:
(1). Computer equipment should not be placed In dusty places (such as windows near the roadside, etc.), if there is really no condition to change the place, you should cover it with a dust cover when not in use; it should not be placed in humid places (such as where water bottles are concentrated) , next to a water dispenser, etc., people pouring water can easily splash water on the equipment), and pay attention to the heat dissipation of the main chassis to avoid direct sunlight shining on the computer;
(2). Computer-specific power supply It is strictly forbidden to use other electrical appliances, hand warmers and other personal electrical equipment on the socket. When leaving work, you should check whether all computer equipment is turned off before leaving;
(3). Do not move the computer while the computer is working;
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(5). Anti-static, anti-dust, do not allow water to enter the keyboard, mouse and other equipment;
(6). Regularly back up the data and organize the disk. Due to the frequent use of hard disks, Some data can easily be lost due to usage, viruses, misoperation, etc. Therefore, it is necessary to back up some important data frequently to prevent all the work completed in several months from being lost due to untimely backup. Defragment the disk frequently and clean up junk files in a timely manner. This will prevent junk files from taking up too much disk space and causing inconvenience to the search and management of normal files. Not only will it be easy to delete important files, but you will also be unable to find the files you need when they are needed urgently;
(7). If problems are found, report them for repair in time to ensure that the machine always works in a good condition. This includes: whether there are any abnormal problems with the equipment and whether the wiring is loose, etc.;
(8). Prevent computer viruses and install anti-virus Software, regularly upgrade and check for viruses
Several points to note when using computers:
1. Automatically link to some unfamiliar websites.
Be careful when surfing the Internet Be careful not to click on anything you don’t understand, especially some pornographic pictures or advertisements floating in the browser page. If it affects your browsing of the web, drag the slider up and down until you get the best viewing angle. .
In addition, try not to install some Internet plug-ins. Also, do not install Internet assistants and toolbars. Such software sometimes affects the normal use of the browser.
2. Don’t. Download and install some small software or programs on the Internet.
3. E-mails from strangers.
Receiving e-mails from strangers, especially Those emails with very tempting titles, such as a joke, or a love letter, etc., with attachments.
4. Check for viruses before using the USB flash drive, and use anti-virus software regularly. Check whether there is a virus in the system.
Several common symptoms when a computer virus attacks:
1. The running speed slows down significantly;
2. It used to be normal. Running software often encounters out-of-memory errors;
3. Prompts some irrelevant words.
4. Generates specific images.
5. Unable to Whatever you do, the hard disk light keeps flashing.
6. The Windows desktop icon changes.
7. The computer suddenly freezes or restarts.
8.
Automatically send e-mails.
9. The mouse is automatically in a busy state.
Possible adverse consequences of computer viruses:
1. The hard disk cannot be started and the data Lost
2. System files are lost or damaged
3. File directory is confused
4. Some documents are lost or damaged
5. Some documents are automatically encrypted
6. The network is paralyzed and normal services cannot be provided.
[Edit this paragraph] Computer maintenance and assembly need to be mastered
Basic composition and development of computers, understanding of the main components of the system
Understanding of system peripherals and commonly used hardware and identification of performance parameters
Hands-on assembly of computers and system software Installation
Installation of system drivers and commonly used software and backup of basic drivers
Backup of files and systems, use of ghost
Backup of files and systems should be decided after Before ghost recovery,
1. First decide which drive to restore (for example, C drive);
2. Then organize the C drive and remove some software installed in the wrong location from the C drive. Do not remove software that relies on the C drive (Pinyin input method, Thunder, office software, wps, etc.) to avoid having to reinstall it after each restore;
3. Then use anti-virus software to completely clean the C drive Antivirus, then use optimization software (Super Rabbit, Optimization Master, etc.) to clean the registry and remove useless information
4. Use ghost to back up the C drive (do not install the backed up files into the backup drive);
5. After the backup is completed, restore the C drive
6. Restart and keep Enter
Basic settings and maintenance of Bios
Basic testing of the system, system optimization, and system security detection
Basic troubleshooting and maintenance