Computer Information Processing _dos/bat

Computer can become a powerful information processing tool, in the modern society plays an extremely important role, it is the outstanding characteristics of its own decision. Computer sets receive information, memory information, processing information, output information and other functions as a whole, he said, the electronic computer is a multi-purpose modern information processor composed of electronic components.
the process of computer processing information
The computer simulates and replaces part of the mental work. Although it has a strong ability, but it is only according to People's will to work, according to the people in advance programmed the process of automatic, high-speed information processing. The process of information processing by electronic computers is the generalization and improvement of the usual methods and rules of daily dealing with problems. Take the example of calculating "30-4*6" to illustrate the computer's working process:
1. The previously choreographed calculation steps and raw data (formulas, commands, etc.) are entered into the memory by the input device.
2. According to the calculation steps, the controller directs the relevant parts to complete the specified operation:
(1) First multiplication, from the memory of the data 4 and 6 sent to the operator, multiplication operations, get charge number 24;
(2) storing the intermediate result 24 in the memory;
(3) The subtraction operation is carried out, and the 30 and meiotic 24 are sent to the operator for subtraction, and the result 6 is obtained.
(4) Send the result 6 of the operator to the memory.
3. The final result of the memory is sent to an output device (such as a monitor or printer), showing or printing an answer.

From the analysis of the above process, it can be clearly seen that the functions of the basic components of the computer and the relationship between them: the controller according to the programming of people to command the other parts of the cooperative work; The memory is like a warehouse, storing data and instructions. The input device sends a series of instructions and data to the internal memory; The output device transmits the result in a certain way (such as displaying, printing, drawing graphics, etc.), the whole system is a very delicate and coordinated organic whole.
The order of computer processing information can also be summed up as: input-processing-output.
The information forms are various, the computer information processing process Examples abound, it is not limited to the arithmetic operation processing, in the language, the text, the sound, the image and so on the processing aspect has obtained the considerable development.
information representation in the computer
All information, such as numbers, characters, Chinese characters and programs, is stored, processed and transmitted within the computer, and is represented by binary codes.
1. Binary number
In the daily life count more Use "decimal". Decimal with "0-9" 10 digital, according to the "every ten into one" principle to count. The computer uses binary numbers as a "language" for sending information to the computer.
First of all, it is more convenient to use binary numbers. Only use the digital "0" and "1" to represent, according to "every two into one" principle count (binary and decimal number corresponding to the relationship as Table 1.) 2. 1 shows). Electronic computers in a large number of components, in these components are the most easily implemented in two states, such as circuit pass and break, pulse and no, high and low potential. These two states are also the most stable, and easy to achieve the control of the circuit itself. A device that has two different stable states and can be converted to each other can be represented by a binary number. There are many things in electricity that represent "0" and "1" in two stable states, for example, the use of electronic components with the bistable operating characteristics, the circuit can be broken to represent the "0", the circuit of the pass represents "1", and such as the light out of the "0", The Light indicates "1" and so on. If you do not use the "binary" and "decimal", you need to find 10 stable state of the electronic components, such components to find it is more difficult, so "binary number" in the electronic components of the expression is the easiest to achieve.

table 1 Conversion tables for binary and decimal numbers

decimal size= Width= "12%" bgcolor= "#ff00ff" >

binary	< Font color= "#ffff80" size= "3" > binary		binary	decimal	binary	decimal
0000	0	0011	3	0110	6	1001	9
0001	1	0100	4	0111	7	1010	10
0010	2	0101	5	1000	8	1011	11

The use of "binary number" of the arithmetic operation is relatively simple, manufacturing cost more economical. There are four rules in binary addition and multiplication formula: addition has 0+0=0,0+1=1,1+0=1,1+1=10, multiplication has 0*0=0,0*1=0, 1*0=0, 1*1=1, and decimal addition and multiplication formula from 0+0 to 9+9, from 0* 0 start to 9*9 each need rule 100.

    2. Binary code
      the number in the electronic computer is represented by the binary, in the computer also uses the binary code to represent the letter, the numeral character, various symbols, the Chinese character and so on. In the process of processing information, several bits of binary code can be combined to represent a wide variety of information. However, because the binary number is not intuitive, people in the actual operation of the computer, the number of inputs and outputs used in decimal, and the specific conversion into binary coding work by the computer software system automatically completed.
      Letters and various characters in the computer transmission is commonly used ASCLL code (American Standard code for lnformation lnterchange), The United States Standard Information Interchange code, which uses a 7-bit binary number to express letters and various common characters (see appendix).
      for the expression of Chinese character information is more complex, China has tens of thousands of Chinese characters, commonly used Chinese characters have more than 7,000, in order to unify, our country has formulated the encoding standard, has stipulated secondary Chinese characters altogether 6,763, Represents a Chinese character in two bytes (16-bit binary code).