What is the history of computer development?

Computers have gone through four generations since they came out:

The first generation of computers (1946- 1958) The main feature of the first generation of computers is that they use electron tubes as logic elements, so people usually call them electron tube computers. Mercury delay line or cathode ray tube is used as main memory, magnetic drum as auxiliary memory, paper tape, card and magnetic tape as input and output, and the program is written in machine language and assembly language. This generation of computers is mainly used for military purposes and scientific research. Large volume, large volume, high power consumption, poor reliability, slow speed and difficult maintenance. Its mainstream machine is UNIVAC.

The second generation computer (1959- 1964) The hardware part of the second generation computer uses transistors as logic elements, which is smaller in size but more functional. This generation of computers is also called transistor computers. The auxiliary memory uses ferromagnetic core, magnetic drum and magnetic disk, and begins to write programs in high-level languages (FORTRAN, COBOL, ALCOL, etc.). ), so management programs appeared. Computers at this stage can "synchronize" input, output and operation. The application of computer has expanded from military field and scientific calculation to data processing and transaction processing. Its size is reduced, its weight is reduced, its power consumption is reduced, its speed is accelerated and its reliability is enhanced. Its mainstream model is IBMT00 series.

The third generation computer (1965- 1970) The hardware part of the third generation computer uses small and medium-sized integrated circuits instead of discrete component transistors, so it is also called a small and medium-sized integrated circuit computer. Microprogram technology and pipeline technology are adopted to improve the flexibility and running speed of the computer; Software management programs have developed into operating systems, and diagnostic programs have appeared. Computers in this period were mainly used for scientific calculation, data processing and process control. Due to the reduction of components and the enhancement of functions, the volume and weight of the computer are further reduced, and the operation speed and reliability are further improved. The mainstream product at this stage is IBM-SVstein/360.

The fourth generation computer (197 1) Up to now, the hardware of the fourth generation computer has adopted large-scale and ultra-large-scale integrated circuits as logic elements, semiconductor memory as main memory, large-capacity soft and hard disks as auxiliary memory, and introduced optical disks. External devices have also developed greatly. Software is more abundant, and database management system appears. The software industry has developed into a modern emerging industrial sector. The volume, capacity and power consumption of the computer are further reduced, and the operation speed, storage capacity and reliability are greatly improved. The appearance of microcomputers began to form networks.

After the above four stages of development, electronic computers are now transitioning to the fifth generation. The fifth generation computer is essentially different from the first four generations. It is an intelligent computer system that combines information collection, storage, processing and communication with artificial intelligence. It can not only carry out numerical calculation and process general information, but also mainly deal with knowledge. It has the ability of reasoning, association, learning and understanding, and can help people make judgments and decisions, explore unknown fields and acquire new knowledge.