A Brief History of computers (I): From computing to multiplication

Everything has a history. Modern computers have gone through addition machines, multiplication machines, analysis machines, and Turing machines. How has today's computers grown to the present? I believe you are very interested.

The earliest people I guess are counting with fingers, so most ancient civilizations use decimal. However, ten fingers are not enough, so people use sticks, stones, grass ropes and other things to count. However, the world's first real computing tool was invented by China during the spring and autumn periods. In the calculation and counting method, the number of units is displayed in two vertical and horizontal directions, where 1-5 are expressed by horizontal and horizontal arrangement of corresponding numbers, 6-9 then the above computing chips are added with the corresponding computing chips below. When multiple digits are used, the single digit uses the vertical type, the ten digits uses the horizontal type, the hundred digits uses the vertical type, and the thousand digits uses the horizontal type, and so on. If the number is zero, it is left empty. This counting method follows the one hundred carry system. Later, China invented the abacus, which showed that China had always been ahead of the world in the field of mathematics.

Computing tools such as abacus, after all, need to be operated by people. For large-scale computing, they are not only inefficient, but also prone to errors. As a result, people naturally think of implementing a mechanical computer. The first mechanical computer in the world was an addition machine invented by French passana in 1642. Pascal, a familiar name? Isn't the physical pressure unit Pascal? Not oneProgramming LanguageIs it Pascal? Yes, they are the same person. Pascal is a talented person and a mathematician, physicist, philosopher, and prose. Unfortunately, tianyao is a talented person. He died at the age of 39. Although he is very short in the world, there are many things left for future generations, if you are interested, you can refer to his "thoughts".

The basic principle of the Pascal addition machine is that the machine has a set of wheels with 10 numbers ranging from 0 to 9 engraved on each wheel. The number on the first wheel on the right represents ten digits, and so on. When adding two numbers, first place a number on the wheel of the addition machine, and then rotate the corresponding number on the corresponding wheel according to the second number, finally, the sum of the two numbers is obtained. If the sum of the numbers on a given digit exceeds 10, the addition machine automatically carries the number through the gear. Because a small wheel turns 10 digits, it forces the next small wheel to turn a number. The calculation result is displayed on the reading window of the addition machine panel. After calculation, the wheel must be restored to zero position. It can be seen that the addition machine invented by Pascal is not a completely mechanical computer. It should belong to a semi-automatic computer, but is automatically implemented in the input space. However, his addition machine guides people at least one way, that is, they can use a pure mechanical device to replace people's memory and thinking.

The addition machine, as its name implies, can only perform addition and subtraction operations, but is powerless to perform multiplication and division operations. However, after 32 years, the multiplication machine was invented by another great genius, levenitz. Are you familiar with this name? Yes, he is the one who invented calculus and binary together with Newton. A large part of the idea of laveniz is inspired by Pascal's addition machine. How can we use machinery to implement multiplication? Obviously, the mechanical device does not carry out multiplication rules. It can only be implemented by continuous addition. In order to realize continuous addition, laveniz invented a device named "stepping wheel. A walking wheel is a long cylinder with nine teeth. Nine teeth are distributed on the surface of the cylinder in sequence. Another gear can be moved along the axial direction to mesh with the stepping wheel one by one. Every time a small gear rotates a circle, the stepping wheel can rotate 1/10 and 2/10 circles respectively according to the number of teeth it mesh with the small gear ......, Until 9/10 circles, so that it can repeatedly add.

The multiplication machine designed by laveniz can perform addition, subtraction, multiplication, division, and other operations, which greatly facilitates the Current mathematical computation. It also laid a solid foundation for future generations to design more powerful computers.