The development of computers has gone through three stages: mechanical computers and what?

The development of computers has gone through three stages: mechanical computers, electromechanical computers and electronic computers. Mechanical computers are composed of mechanical components such as levers and gears rather than electronic components; electronic computers are modern electronic computing machines used for high-speed calculations. They can perform numerical calculations, logical calculations, and have storage and memory functions.

The operating environment of this tutorial: Windows 7 system, Dell G3 computer.

The development of computers has gone through three stages: mechanical computers, electromechanical computers and electronic computers.

Mechanical computer

A mechanical computer (English: mechanical computer) is composed of mechanical parts such as levers and gears rather than electronic parts. The most common examples are adding machines and mechanical counters, which use the rotation of gears to increase the output of a display. More complex examples can perform multiplication and division. A model for calculating square roots was sold in the 1960s.

A mechanical computer can be an analog that uses a smooth mechanism (such as a curved board or slide rule) to perform calculations, or a digital computer that uses gears.

Mechanical computers reached their peak during World War II, where they formed the basis of complex bombsights, including the Norden, and similar ship computing devices such as the Torpedo Data Computer in the United States and the Admiralty Fire Brigade in the United Kingdom. It is important to note that mechanical flight instruments on early spacecraft provided calculated output as an indication of surface displacement rather than in numerical form. From Yuri Gagarin's first manned spaceflight until 2002, every manned Soviet/Russian spacecraft Vostok, Voskhod and Soyuz spacecraft were equipped with Globus instruments, which displayed the spacecraft's position through moving miniature globes. Displacement above the Earth, plus latitude and longitude indicators.

Mechanical computers continued to be used into the 1960s, but were quickly replaced by electronic calculators that appeared in the mid-1960s and used the output of cathode ray tubes. This evolution reached its peak in the 1970s with the introduction of inexpensive handheld electronic calculators. Mechanical computers gradually disappeared in the 1970s and became extinct by the 1980s.

Electromechanical Computer

Next let’s talk about an excellent example of an electromechanical calculating machine

Electromechanical tabulating machine

Hollerith's tabulating machine is mainly used to solve the problem of the U.S. Census.

Census, you can imagine that it is naturally used for statistical information, gender, age, name, etc.

If it is purely manual statistics, you can imagine how complicated this is.

The tabulation machine applies perforation technology to data storage for the first time. You can imagine that using perforation and non-punching Holes are used to identify data

But the design was not very mature at that time. For example, if it were modern, we would definitely use a position to indicate gender. Maybe if a hole was punched, it would be a girl, and if it was not punched, it would be a boy.

At that time, it was a card There are two positions used on it, which means that men should punch holes at the place marked M, and women should punch holes at the place marked F. However, it was also very advanced at the time. Then, specialized punchers used piercing The machine stamps the resident information on the card

The next step is to collect statistical information

Use the on and off of the current to identify the data

Corresponding to each data hole on the card, there is a metal needle on the top, and a container on the bottom. The container contains mercury

When the pressure plate is pressed, the needle can pass through the hole in the card and come into contact with the mercury, and the circuit When connected, where there is no hole, the needle is blocked.

How to map circuit continuity to the required statistical information?

This uses mathematical logic and logic circuits

The top pin is the input, through the input of the punched card

The relay below is the output. According to the result, the energized M will generate a magnetic field, pull the specific lever, and turn the gear to complete the count.

Did you see that at this time, the punched card can be used as input, the logic circuit composed of relays can be used as the arithmetic unit, and the gear can be used for counting output.

Involved in the tabulation machine The main components include: input/output/operation

In 1896, Hollerith founded the tabulating machine company, the predecessor of IBM...

Computer, commonly known as computer, is a modern electronic computing machine used for high-speed calculations. It can perform numerical calculations, logical calculations, and also has storage and memory functions. It is a modern intelligent electronic device that can run according to the program and process massive data automatically and at high speed.

It is composed of a hardware system and a software system. A computer without any software installed is called a bare metal computer. It can be divided into five categories: supercomputer, industrial control computer, network computer, personal computer, and embedded computer. The more advanced computers include biological computers, photon computers, quantum computers, etc.

Computer applications are becoming more and more common in China. After the reform and opening up, the number of Chinese computer users continues to rise, and the application level continues to improve. In particular, applications in the Internet, communications, multimedia and other fields have achieved good results. From 1996 to 2009, the number of computer users increased from 6.3 million to 67.1 million, and the number of networked computers increased from 29,000 to 59.4 million. Internet users have reached 316 million, and wireless Internet users have 670 million mobile users, including 117 million mobile Internet users, ranking first in the world.

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