The composition and function of computer

The composition and function of computer

The computer consists of five components, the computer, the controller, the memory, the input device and the output device, each of which performs the specific basic functions as required.
(1) The main function of an operator or arithmetic logic unit (arithmetical and Logical unit) is to perform various operations on the data. Besides the basic arithmetic operations of addition, subtraction, multiplication and addition, these operations include the logical processing ability of "logical judgment", which is the basic logic operation of "and", "or", "non", and the comparison and shift of data.
(2) The main function of memory unit memory is to store the program and various data information, and to complete the program or data access at high speed and automatically during the operation of the computer. Memory is a device with a "memory" function, which stores information using physical devices with two stable states. These devices are also known as memory components. Since the memory element has only two stable states, the data is represented in a computer using only two digital "0" and "1" binary. The two stable states of the memory element are expressed as "0" and "1" respectively. The decimal number that is used daily must be converted to the equivalent binary number in order to be stored in memory. Various characters processed in the computer, such as English letters, arithmetic symbols, are also converted to binary code to store and manipulate. Memory is composed of thousands of "storage units", each storage unit holds a certain number of digits (microcomputer is 8 bits) of the binary number, each storage unit has a unique number, called the address of the storage unit. "Storage Unit" is the basic unit of storage, different storage units are differentiated by different addresses, as if residents of a street in a residential area are separated by different house numbers. The computer uses the way of address access to the storage of data and data, that is, in a computer program, whenever the need to access data, to the memory to send an address to indicate the location of the data, while issuing a "hold" command (accompanied by the data to be stored), or issue a "take out" command. This approach to address storage is characterized by direct access to the address of the data as long as it is known. However, there are shortcomings, that is, a data is often used to occupy multiple storage units, the need to continuously access the relevant storage unit is a complete data. Before the computer is calculated, the program and data are fed into the memory by the input device, and after the computer has begun to work, the memory also provides information for the other parts, as well as the intermediate and final results. Therefore, the memory number and the speed of fetching is a very important performance index of the computer system.
(3) The Controller unit controller is the control center of the whole computer system, which directs the various parts of computers to work in a coordinated manner to ensure that the computer is operated and handled methodically in accordance with the predetermined goals and procedures. The controller extracts the instruction from the memory, analyzes what operation is required by each instruction and the storage location of the necessary data, and then gives the control signal to the other parts of the computer according to the result of the analysis, and directs the whole computer to complete the operation stipulated by the instruction. Therefore, the process of automatic computer operation, is actually the process of automatic execution of programs, and each instruction in the program is performed by the controller, it is the computer to achieve "program control" of the main components. The controller and the operator are usually called the central processing Unit (processing UNIT-CPU). In industrial production, the most advanced VLSI technology is always used to manufacture CPU chips. It is the core part of the computer. Its performance, mainly working speed and calculation accuracy, has a comprehensive impact on the overall performance of the machine.
(4) The input device, the device used to enter various raw data and programs into the computer, is called the input device. The input device converts various forms of information, such as numbers, text, and images, into digital "encodings," which the computer can recognize as binary codes (in fact, electrical signals) in the form of 1 and 0, and store them "input" into the computer. Keyboards are essential input devices, commonly used input devices and mouse, graphics input boards, video cameras, and more.
(5) The output device is a device that outputs various types of data from a computer called an output device. The output device transforms the results of computer processing (still digital form encoding) into information forms such as text, numbers, graphics, sounds, voltages, which can be received and recognized by people or other devices. Common output devices are display, printer, plotter and so on.

The composition and function of computer