PC system unit: device and the role of the motherboard
System unit: internal content
The main component of any computer is the system unit, since it is in it that all the important elements and nodes are located, due to which the PC is able to fully function. The system unit is a metal box (case), “stuffed” with certain contents. In particular, the system contains:
electronic circuits that control the operation of the PC (RAM, or OP, processor, motherboard, device controllers, and so on);
drives on hard and flexible magnetic disks, optical drives;
a power supply unit that converts the AC voltage of the network into a low DC voltage necessary for the operation of electronic circuits and drive motors of drives and so on;
cooling system (fans and radiators), which provides the necessary temperature conditions.
Equipment located outside the system unit refers to external input and output devices. External devices of the system unit are called peripheral. On the front side of the system unit are located:
Power – a button by pressing which the PC turns on and off;
Reset – a button responsible for restarting the PC in the event of a freeze, that is, when the computer stops listening to commands due to one or another error in its operation;
two indicators (luminous bulbs) – a power indicator (steady on) and an indicator of the hard drive (lit when information is either written to or read from a disk).
On the front side of the unit there are disk drives. This is a small FDD floppy drive, and a retractable CD or DVD drive. In addition, additional connectors (USB, sound) are also output to the front panel for convenience.
“Behind the rear”, that is, on the back wall of the unit you can see many different detachable connections to which external devices are connected, including a monitor, system power (often these devices are powered separately), speakers, microphone, printer, mouse and keyboard (detachable connections different colors) and others. As a rule, the sockets have a different shape – the uniqueness of each connector allows you not to get confused with the connections.
The case of the system unit can be vertical and horizontal. Recently, vertical Midi Tower (medium) and Big Tower (large) hulls are considered more perfect. The power supply unit (PSU), as a rule, is already built into the case. By the way, when purchasing a system unit or assembling it, you should pay attention to the power of the PSU, which can be 250 W, 300 W, 350 W, 400 W. The latter option is the best, but in principle, any power is enough to ensure the energy consumption of all devices that are connected to the computer. It is the efficiency of the power supply that determines the quality and stability of the entire system.
The purpose of the motherboard
The motherboard or system board is the most important PC node. The main purpose of the motherboard is to be responsible for communications (bridges) between all PC devices that need to be controlled and whose work needs to be coordinated. This is what she “does.” In fact, the motherboard is the main electronic circuit of the computer, on the operation of which not only the speed of the PC, but also the stability and quality of its work, entirely depends.
The motherboard consists of a number of devices, including:
a system bus is a backbone that links computer devices into a single unit. Data and control signals are sent over this bus;
a chipset is a basic “package” of logic chips with which the motherboard controls all the processes occurring inside the system unit. The chipset is the foundation, the foundation of any motherboard, and it depends on it the type of processor, OP and the performance of the motherboard;
A small BIOS scheme, the main function of which is to manage standard peripheral devices, in particular drives, keyboards, timers, printers and others. In addition, the BIOS speeds up PC loading, disables unnecessary functionality, and tests PC hardware.
In addition, the structure of the motherboard suggests the presence of other elements that are placed on separate boards and inserted into detachable connections. These are the so-called slots that look like long nests. The number of slots determines how many additional cards can be inserted into the computer. The video card is connected through a special slot called AGP or PCI Express, the remaining slots are called PCI. On the motherboard there are slots for installing the OP. The number of these slots varies from 1 to 4, which allows you to have up to 4 GB of RAM. Slots are directly tied to the type of OP.
Among other things, on the motherboard there are special microprocessors, connectors for the OP modules, for connecting hard disk drives and providing power, as well as other elements.
It must be understood that the failure of the motherboard is a much more serious problem than the failure of, say, a power supply. Therefore, it is advisable to contact the service center and not try to “cope” with the motherboard yourself.