The development history of information technology Human beings have a long history of communication. As early as ancient times, people exchanged information through simple language, murals and other methods. For thousands of years, people have been using language, symbols, bells and drums, fireworks, bamboo slips, paper books, etc. to convey information. The ancient people's beacon fire, flying pigeons to convey messages, and stagecoach mail are examples of this. There are still some primitive tribes in some countries that still retain ancient communication methods such as drumming and trumpeting. In modern society, the command sign language of traffic police and the flag language used in navigation are nothing but the result of the further development of ancient communication methods. The basic method of transmitting these information relies on human vision and hearing. After the mid-19th century, with the invention of the telegraph, the telephone, and the discovery of electromagnetic waves, fundamental changes occurred in the field of human communication. It was possible to use metal wires to transmit information, and even conduct wireless communication through electromagnetic waves, making the mythical " "Ears to the wind" and "clairvoyance" have become a reality. From then on, human information transmission could break away from conventional visual and auditory methods and use electrical signals as new carriers. This brought about a series of iron technology innovations and began a new era of human communication. In 1837, American Samuel Morse successfully developed the world's first electromagnetic telegraph. Using the electrical code he designed, he could convert the information into a series of long or short electrical pulses, send them to the destination, and then convert them into the original information. On May 24, 1844, Morse sent the first telegraph in human history "using Morse code", thus realizing long-distance telegraph communication. In 1875, Scottish young man Alexander Bell (A.G. Bell) invented the world's first telephone. And applied for a patent for the invention in 1876. In 1878, the first long-distance telephone experiment was conducted between Boston and New York, which was 300 kilometers apart, and was successful. Later, the famous Bell Telephone Company was established. In 1888, the young German physicist H.R. Hertz conducted a series of experiments using a radio wave ring and discovered the existence of electromagnetic waves. He used experiments to prove Maxwell's electromagnetic theory. This experiment caused a sensation in the entire scientific community and became an important milestone in the history of modern science and technology, leading to the birth of radio and the development of electronic technology. The discovery of electromagnetic waves had a huge impact. In less than 6 years, Popov of Russia and Marconi of Italy invented wireless telegraphy respectively, realizing the radio transmission of information, and other radio technologies also sprung up. In 1906, American physicist Fessenden successfully developed radio broadcasting. In 1920, American radio expert Conrad established the world's first commercial radio broadcasting station in Pittsburgh. The discovery of electromagnetic waves also prompted the rapid development of image transmission technology. In 1922, Philo Farnsworth, a 16-year-old American high school student, designed the first schematic diagram of a television fax and was judged to be the first person to invent television. In 1928, Zvorkin of the United States invented the photoelectric picture tube and collaborated with engineer Van Wass to realize electronic scanning television transmission and transmission. In 1935, a television station was set up in the Empire State Building in New York, USA, and the following year it successfully sent television programs to places 70 kilometers away. In 1938, Zvorkin produced the first practical television camera. After people's continuous exploration and improvement, in 1945, based on the working principle of three primary colors, RCA produced the world's first all-tube color television. It was not until 1946 that American Ross Weimar invented a high-sensitivity camera tube. In the same year, Japanese Professor Hachimoto solved the problem of receiving antennas for home televisions, and televisions quickly became popular. In addition, remote control, telemetry and remote sensing technology as information super-remote control are also very important technologies.
Remote control is a technology that uses communication lines to control remote controlled objects. It is used in electrical industry, oil pipelines, chemical industry, military and aerospace industry; telemetry is to measure physical quantities that need to be measured in a distance, such as voltage, current, air pressure, etc. A measurement technology that converts temperature, flow, etc. into electricity and transmits it to an observation point using communication lines
It is used in the meteorological, military and aerospace industries; remote sensing is a comprehensive measurement technology that is used in Sensors are used to receive electromagnetic wave information radiated by objects at high altitude or at a distance. The processed or identifiable images or recording tapes used by electronic computers prompt the properties, shapes and changing dynamics of the measured objects. They are mainly used in meteorology, military and aerospace. cause. With the rapid development of electronic technology, the computing tools that are urgently needed for military and scientific research have also been greatly improved. In 1946, Eckert and Moshiri of the University of Pennsylvania developed the world's first electronic computer. Innovations in electronic component materials have further promoted the development of electronic computers in the direction of miniaturization, high precision, and high reliability. In the 1940s, scientists discovered semiconductor materials and used them to make transistors, replacing electron tubes. In 1948, Shockley, Bardeen, and Brattain of Bell Labs in the United States invented the transistor, and transistor radios, transistor televisions, and transistor computers quickly replaced various vacuum tube products. In 1959, Kilby and Noyce in the United States invented the integrated circuit, and microelectronics technology was born. In 1967, large-scale integrated circuits were born, and more than 1,000 transistor circuits could be integrated on a silicon wafer the size of a grain of rice. In 1977, American and Japanese scientists created a very large-scale integrated circuit, integrating 130,000 transistors on a 30-square-millimetre silicon wafer. Microelectronics technology has greatly promoted the upgrading of electronic computers, allowing electronic computers to display unprecedented information processing functions and becoming an important symbol of modern high-tech. In order to solve the problem of resource sharing, a single computer quickly developed into a computer network, realizing data communication and data sharing between computers. Communication media have developed from ordinary wires and coaxial cables to twisted pairs, optical fiber wires, and optical cables; the input and output devices of electronic computers have also developed rapidly, such as scanners, plotters, audio and video equipment, etc., making computers even more powerful and capable of processing more complex issues. The rise of multimedia technology in the late 1980s gave computers the ability to comprehensively process various forms of information such as text, sound, images, and movies, and has increasingly become the most important and indispensable tool for information processing. At this point, we can preliminarily believe that: Information Technology (IT) is a general term for technical systems based on microelectronics and optoelectronics technology, supported by computer and communication technology, and with information processing technology as the theme. It is a comprehensive sexual technology. The close integration of electronic computers and communication technology marks the arrival of the digital information age. 2 The Internet is the largest computer network in the world. It originated from the ARPANET, a computer experiment network developed by the Advanced Research Projects Agency (ARPA) of the U.S. Department of Defense in 1968 to support military research. The original intention of building the ARPANET network was to help researchers working for the U.S. military exchange information through computers. Its design and implementation are based on the dominant idea: the network must be able to withstand failures and maintain normal operation. When the network When one part of the network becomes inoperable due to an attack, other parts of the network can still maintain normal communications.
In the early 1990s, with the development of WWW, the Internet gradually moved towards civilian use. Since the good interface of WWW greatly simplified the difficulty of Internet operation, the number of users increased sharply. Many government agencies and commercial companies realized that the Internet had huge potential, so A large number of people have joined the Internet, so the number of points on the Internet has greatly increased, and the information on the Internet is diverse and rich. Now the Internet has penetrated into every part of people's lives. Through WWW browsing, e-mail, etc., people can get what they want in a timely manner. The Internet has greatly facilitated the dissemination of information and brought people a new way of communication. It can be said that the Internet is another revolution in human communication since the invention of the telegraph and the telephone. The development of the Internet in my country is relatively late, but it is still relatively rapid. In 1987, the Beijing Institute of Computer Applications took the lead in opening an X.25 line to Germany. Since then, the Chinese Academy of Sciences, Tsinghua University, and Peking University have established their own campus networks and connected to the Internet. Based on this my country's Internet is beginning to take shape. In recent years, the scale of the Internet has grown rapidly and has covered 154 countries, including my country. In 1994, China's Internet had only one international export line with more than 300 Internet users. By 1996, it had developed to 7 international export lines and 20,000 Internet users. There are multiple network users, and by 1995, my country had initially built four major backbone networks: China Scientific Research Network (CASNET), which is operated by the Chinese Academy of Sciences. China Education and Research Internet Network (CERNET) is operated by Tsinghua University. China Jinqiao Information Network (CHINAGBN) is supported by the Ministry of Electronics, the Ministry of Electric Power and the Ministry of Railways and is operated by Jitong Company. Chinanet was established by the Ministry of Posts and Telecommunications. Chinanet is my country's first commercial network. The first phase of the project was completed in June 1995, and two international export lines with a bandwidth of 64Kbps were opened in Beijing and Shanghai. It is expected that after the completion of the second phase of the project, it will cover the national backbone network in all provinces and cities, and the bandwidth of the export line will increase from 64K to 2M. CHINANET currently covers 31 provinces and cities across the country, with 86Mbps international dedicated lines. The establishment of the above four major backbone networks has laid a good foundation for the use and development of the Internet in our country. I believe that the Internet will have a good future in our country.