1.12. The structure of modern computing systems

In the structure of today's PC type IBM PC there are several main components:

• a system unit that organizes work, processes information, performs calculations, provides communication between a person and a computer. The composition of the PC system unit includes a motherboard, speaker, fan, power supply, two drives;

• system (motherboard), representing several dozen integrated circuits for different purposes. The integrated circuit is based on a microprocessor, which is designed to perform calculations on the program stored in the storage device and the overall control of the PC. The speed of the PC depends on the speed of the processor;

• PC memory, which is divided into internal and external: a) internal (main) memory is a memory device associated with the processor and designed to store used programs and data that are involved in the calculations. Internal memory is divided into operational (random access memory - RAM) and permanent (permanent storage - ROM). RAM is designed for receiving, storing and issuing information, and permanent - for storing and issuing information; b) external memory (external storage device - OVC) is used to accommodate large amounts of information and exchange it with RAM. By design, the OVCs are separated from the central PC devices;

• audio card (sound card) used to play and record sound;

• video card (video card), which provides playback and recording of video signal.

The external input devices in the PC are:

a) keyboard - a set of sensors that perceive pressure on the keys and close some electrical circuit;

b) a mouse - a manipulator that simplifies working with most computers. There are mechanical, optical-mechanical and optical mice, as well as wired and wireless;

c) scanner - a device that allows you to enter into a computer in a graphical form, text, pictures, photographs, etc.

External information output devices are:

a) a monitor used to display various types of information on the screen. The size of the monitor screen is measured in inches as the distance between the lower left and upper right corners of the screen;

b) a printer used to print text and graphics prepared on a computer. There are matrix, inkjet and laser printers.

External input devices are used to ensure that information that the user possesses is made available to the computer. The main purpose of the external output device is to present the available information in a form accessible to the user.