Today, computer devices have become so firmly entrenched in our lives that it seems impossible to imagine our existence without them. However, most users almost never think about how all these systems work. Next, we will consider how the computer is arranged (for "dummies", so to speak). Of course, it will not work to describe everything in detail and to cover all the technical aspects (yes, this is not necessary for the majority). Therefore, we restrict ourselves to the main aspects, speaking in a simple "human" language.
Computer for "dummies": the main components
Speaking about the device of any computer device, it should be clearly understood that at its core it consists of hardware and software.
The hardware refers to all connected devices that, so to speak, can be touched by hands (processors, memory sticks, hard drives, monitors, video, audio and sound adapters, keyboards, mice, peripherals such as printers, scanners, etc. . d.). In the people, all these components are sometimes called "computer hardware."
The software part consists of many components, among which the operating system plays the main role, on the basis of which the interaction between the hardware and other programs and the device drivers installed in it are made — special programs with which the OS can interact with the hardware itself and enable it when performing certain tasks.
From this it is not difficult to conclude that the main principle of operation of a computer of any type is the interaction of hardware and software components. But this is only a superficial representation. These processes will be described a little later.
Computer hardware
In the hardware, according to many, in the first place are the processor and RAM. In part, this is so. They provide the execution of all program commands and make it possible to run certain processes.
On the other hand, if you dig deeper, not a single “iron” component costs anything by itself, because you need to connect it somewhere to use it. And here the paramount importance is given to the so-called motherboards (popularly referred to as “motherboards”) - special devices on which all other components, microcircuits are mounted, etc. In this sense, the basic principle of computer operation (correct functioning without failures) is is to correctly connect all hardware components through the corresponding controllers to special slots or connectors on the board itself. There are rules here, for example, on the correct use of PCI buses, on connecting hard drives and removable drives using the Master / Slave principle, etc.
Separately, it is worth mentioning the read-only memory (ROM), on which information is recorded, as it were, forever, and the random-access memory (RAM), which serves to execute software components.
Types of software
The software principle of the computer involves the use of appropriate software to perform tasks.
In a general sense, software is divided into several categories, among which system and application software can be separately distinguished . The system software includes the operating systems themselves, device drivers, sometimes service utilities necessary to ensure the correct operation of the entire system. This, so to speak, is a common shell into which application programs and applications are embedded. This type of software has a strict focus, that is, it is focused on the performance of a specific task.
But since it is precisely what the basic principles of computer operation are in a general sense, it is system software that comes to the first place. Next, consider how the entire computer system starts.
Computer science lesson. Computer: turning on and checking devices
Probably, many users of stationary PCs noticed that when you turn on the computer, the characteristic sound of the system speaker is heard. Few people pay attention to it, however, from the fact of its appearance, we can conclude that all the "iron" devices are working properly.
What is it? The principle of computer operation is that when power is supplied to a special microcircuit, called the primary input / output device, all devices are tested. First of all, there is a detection of malfunctions in the video adapter, because if it is not in order, the system simply will not be able to display visual information on the screen. Only then is the type of processor and its characteristics, parameters of RAM, hard disks and other devices determined. In fact, the BIOS initially stores information on the entire hardware.
Download Options
In addition, the download can also be interpreted as the software principle of computer operation, since the verification takes place precisely in software, and not in a physical way.
There is also a system for selecting a boot device (hard disk, optical media, USB device, network, etc.). In any case, the further principle of the computer’s work in terms of loading is to have the so-called boot record necessary for starting the system on the device.
Operating system start
To boot the OS, you need a special bootloader that initializes the kernel of the system recorded on the hard disk and puts it into RAM, after which process control is transferred to the OS itself.
In addition, the master boot record can also have more flexible settings, giving the user the right to choose a bootable system. If the start is made from removable media, the executable boot code is read from it, but loading in any version is done only if the BIOS determines the executable code as valid. Otherwise, a notification about the impossibility of starting will appear on the screen, such as that the boot partition was not found. In this case, a partition table is sometimes used, which contains information about all logical disks into which the hard drive can be divided. Among other things, access to information directly depends on the structure of the file organization, which is called the file system (FAT, NTFS, etc.).
Note that this is the most primitive interpretation of the boot process, because in fact, everything is much more complicated.
Computer memory: running programs
So, the operating system has booted. Now let us dwell on the functioning of programs and applications. First of all, the central processor and RAM are responsible for their implementation, not to mention the drivers of other devices involved.
The principle of operation of the computer’s memory is that when the executable file of the program or other object is launched from the ROM or removable media, when the application plays a complementary role, some associated components, most often dynamic libraries (although for simple programs their presence may not be provided), and device drivers necessary for operation.
They provide a link between the operating system, the program itself, and the user. It is clear that the larger the RAM has, the more components can be loaded into it and the faster they will be processed. Upon receipt of interaction commands, the central processor enters the case, which performs all the computational actions in the system. Upon completion of the application or when you turn off the computer, all components from the "RAM" are unloaded. But this does not always happen.
Change system settings
Some processes may reside in RAM permanently. Therefore, they must be stopped manually. On Windows systems, many services start automatically, but to the user they are completely unnecessary. In this case, the autostart setting is applied. In the simplest version, optimizer programs are used that clean up unnecessary processes and remove computer trash in automatic mode. But this is a separate conversation.