From the analysis of the above process, we can clearly see the functions of the basic components of the computer and Their Relationships: the Controller directs the coordination of other components according to the program compiled by people; the generator undertakes specific computing tasks. The memory stores data and commands like a warehouse. The input device sends a series of commands and data to the internal memory; the output device transmits the results in certain ways (such as display, printing, and drawing). The entire system is a very delicate and coordinated organic whole.
The order of computer processing information can also be summarized as: Input-processing-output.
Information is represented in a variety of forms, and there are countless examples of computer information processing processes. It is not limited to arithmetic operations, it has made great strides in processing language, text, sound, images, and other information.
Information Representation in the computer
All information such as numbers, characters, Chinese characters, and programs is stored, processed, and transmitted in the computer.Code.
1. Binary Number
In daily life, the count is mostly in decimal format ". 10 digits in decimal format "0-9" are counted based on the principle of "every ten in one. The computer uses binary numbers and uses them as the "language" for information transmission ".
First, it is easier to use binary numbers. It is represented by digital "0" and "1", and is counted according to the "every two to one" principle (the ing between binary and decimal numbers is shown in Table 1.2.1 ). Electronic computers use a large number of electronic components. The two States of these components are the easiest to achieve, such as circuit communication and disconnection, pulse having and absence, and potential high and low. These two states are also the most stable and easy to control the circuit itself. A device with two different stable states that can be converted to each other can be represented by binary numbers. In electricity, there are a lot of things that represent "0" and "1" in two stable states, such as using the bistability characteristics of electronic components, the circuit can be broken to "0", the circuit represents "1"; and if the light is off, it means "0", the light indicates "1", and so on. If "decimal" is used instead of "binary", it is necessary to find the electronic components with ten stable states. It is difficult to find such components, therefore, the representation of binary numbers in electronic components is the easiest to implement.
Table 1 Comparison Between Binary and decimal numbers
The "binary number" arithmetic operation is also relatively simple, and the manufacturing cost is more economical. There are four rules for addition and multiplication of binary: addition has 0 + 0 = + 1 = + 0 = + 1 = + 1 = 10; multiplication has 0*0 = 0 0*1 = 0, 1*0 = 0, 1*1 = 1, the addition and multiplication formulas of decimal numbers start from 0 + 0 to 9 + 9, and 100 rules are required for each formula from 0*0 to 9*9.
2. binary Code
the number in an electronic computer is represented by binary. in the computer, binary code is used to represent letters, numbers, symbols, and Chinese characters. In the process of processing information, several bit binary codes can be combined to indicate a variety of information. However, because the binary number is not intuitive, when people perform operations on the computer, the number of input and output uses decimal, and the specific conversion to binary encoding is automatically completed by the computer software system.
American Standard Code for lnformation lnterchange (American Standard Code for lnformation lnterchange) is widely used for the transmission of letters and various characters in computers, it uses 7-bit binary numbers to express letters and a variety of common characters (see the appendix ).
the representation of Chinese characters is complex. There are tens of thousands of Chinese characters and more than 7000 commonly used Chinese characters in China. In order to unify Chinese characters, China has developed Chinese character encoding standards, 6763 Chinese Characters in level 1 and level 2 are specified, and two bytes (16-bit binary code) are used to represent a Chinese character.