Because the operating system is related to the hardware to a certain extent, it is difficult to learn the operating system without knowing the general introduction to the computer. I hope that some of the things summarized will be helpful to some friends who are not very familiar with computer principles. Reference book "Brother Bird's Linux Private Kitchen".
1. Computer development
1.1、
In fact, the computer is: accepting the user's instructions and data, transporting and processing the data and logic units through the central processing unit, and finally generating valid information. So the original computer design was like this.
People input information into the computer through the input device, the computer processes the information through the central processing unit, and then tells everyone the processed result through the output device.
The world's first generation computer "ENIAC" was born in 1946 at the University of Pennsylvania in the United States. The computer design of the time was very poor, and there were no convenient tools such as mouse (Dr. Doug Engelbart) and keyboard. At that time, the computer was still a big guy, covering an area of 170 square meters and the height of a two-story building. It can perform 5000 operations per second. People can only input information to the computer by flipping the countless switches on the huge panel of the computer, and after the computer processes the information, the output device is also quite simple, that is, the countless signal lights on the computer panel. So computers at that time simply couldn't handle the wide variety of information they are now, they were really only able to do number crunching.
1.2、
as the amount of data increases. It was found that the original computers were already struggling to calculate large amounts of data. So the original computer model was improved by adding an internal memory next to the central processing unit.
The computer process becomes the data of the input unit into the memory, the cpu reads the data from the memory, and the data processed by the cpu must also be written back to the memory, and finally the data is transmitted from the memory to the output unit. Comparing the two models is equivalent to the teacher assigning a math problem. Before, you could only do mental arithmetic, but now you are provided with a scratch paper.
1.3、
With the development of the times, people feel the backwardness of input and output equipment, so the paper tape machine appeared. The working principle of the paper tape machine is as follows: each line of the paper tape is marked with 26 letters, 10 numbers and some operation symbols. If a hole is punched in the letter A of this line, it means that the letter A is to be entered here. , in the same way, the next line may be the letter H, and the next line may be the number 1.
Such a long paper tape can replace a lot of information. People put this paper tape into the paper tape machine, and the paper tape machine also translates the information on the paper tape to the computer, because the computer cannot understand the paper tape.Although still relatively troublesome, this progress has indeed greatly contributed to the development of computers.
At the same time that paper tape was invented, improvements were made to the output system, replacing the countless signal lights on computer panels with printers. The role of the printer is just the opposite of that of the paper tape machine. It is responsible for translating the information output by the computer into a language that humans can understand and printing it on paper. In this way, people can easily see the output information, and no longer have to look at the hundreds of signal lights. 1.4,