In this lesson we will look inside the system unit and Let's get acquainted with all the main internal components computer.
In the third lesson we learned what a processor, RAM and hard drive are needed for. In the fourth lesson, we saw the outside of a computer and learned what the various buttons and connectors are for. Today we will open the cover of the system unit and get acquainted with all the internal components.
When people talk about the internal structure of a computer, they usually mean those components that are located inside its housing. For a desktop computer, the case is the system unit; for laptops and netbooks, it is the lower of the opening halves (let me remind you that we were dedicated to types of computer equipment).
To begin with, let's take a system unit that is not too new, but also not too old, in which all the main components are installed. And then we compare it with a more inexpensive option with fewer additional components.
So, let's look at the photo of the system unit of the IT lessons website.
What we see if we remove the cover of the computer system unit
The first thing that catches your eye is a lot of all sorts of printed circuit boards, “boxes” and wires. All boards and devices in a separate case are components that perform different tasks. Using wires, components exchange information and receive electrical power.
Let's look at all the components one by one.
All computer components are interconnected by one of the largest printed circuit boards (which can be immediately recognized in the photograph by their size), it is called system board or motherboard(in English version motherboard or mainboard).
System board (system unit component)
Some components are installed directly into the connectors located on the motherboard, while other components are connected to it using special wires into the corresponding connectors, and are installed in special compartments of the case.
You can learn more about the motherboard from subsequent IT lessons, but at a higher level of knowledge.
In order for all components to perform their task, they must be powered with electrical energy. To supply this energy it is used computer power supply(in English power supply unit or PSU), from which wires stretch throughout the system unit.
Most devices have a special connector for connecting power, but some receive electrical energy through (which in this case will be an intermediary between the power supply and the device).
We already got acquainted with the processor in, let me remind you that the task of the processor is to process information.
CPU(English) central processing unit And CPU) is installed in a special connector on the system board (the English name of the connector is “ Socket"). The processor socket is usually located at the top of the motherboard.
After installing the processor in the socket, a cooling system is installed on top - cooler(aluminum radiator with fan).
In the photo we see the cooler, under which the central processor is located.
We also got acquainted with RAM in the third lesson.
RAM(RAM, Random Access Memory, RAM), like the processor, is installed in special sockets on the motherboard.
RAM (system unit component)
RAM is made in the form of a small printed circuit board with memory chips installed on it, this whole design is called “ memory module" Due to the specific shape of the board, it is called a “bar”.
The photo shows that there are four connectors, and two RAM modules, and they are installed in connectors of the same color to increase operating speed (more about this mode in subsequent IT lessons at more “advanced” levels).
Video card(video adapter, graphics adapter, graphics card, graphics card, video card, video adapter, display card, graphics card, etc.) is designed for processing graphic objects that are displayed in the form of an image on the monitor screen.
The photo shows that in this case the video card is made in the form of a printed circuit board ( expansion cards), inserted into a special connector on the system board (expansion slot). Since this video card gets very hot, you can see large cooling system(yes, this is also a cooler).
For the first time in IT lessons, we came across the concepts of “expansion card” and “expansion slot”, so we will immediately set a definition from which we will build in the future.
Expansion card– a device in the form of a printed circuit board with a universal connector for installation on the system board (for example, a video card, network card, sound card).
Expansion cards are installed in addition to the main components in order to expand your computer's capabilities, they can have different purposes (graphics processing, sound processing or connection to a computer network, etc.).
Example of an expansion card (a simpler video adapter)
Expansion slot- a special universal connector on the system board, designed for installing additional computer devices in the form of expansion cards.
We've sorted out the new definitions, let's move on.
LAN card(network adapter, Ethernet adapter, network adapter, LAN adapter) is designed to connect a computer to a computer network.
Network card (system unit component)
In this case, the network card is also made in the form of an expansion card (printed circuit board), which is installed in a connector on the system board.
Sound card(audio card, sound adapter, sound card) processes sound and outputs it to speaker systems or headphones.
Sound card (system unit component)
Like the two previous devices, a sound card is a printed circuit board inserted into a connector on the system board. True, this sound adapter is not an ordinary one, it consists of two printed circuit boards, but this is an exception to the rule.
On hard drive All computer programs and data are stored (more about this in the IT lesson).
The hard drive, unlike previous components, is not installed on the motherboard, but is attached in a special compartment of the case system unit (look at the photo).
Hard drive (aka hard drive)
You can install multiple hard drives in such bays and increase the amount of internal memory on your computer.
Hard drive is sometimes referred to by the acronym NMJD(Hard Magnetic Disk Drive), often said " Winchester"and in English hard disk drive or HDD.
Optical drive(DVD drive, optical disc drive or ODD) is needed to read and write DVD and CD discs. Like a hard drive, an optical drive is installed in a special compartment system unit.
Optical drive (system unit component)
This compartment is located at the top front of the case, it is wider than for the hard drive, since the DVD drive is noticeably larger.
So, we have looked at all the main components of the system unit. Now let’s see how the internal structure of a computer can differ using an example less expensive PC option.
The same components are visible in the photo, but expansion cards (video card, network card and sound card) are not visible. How will this computer work without these components? In fact, these components exist, but they are not visible at first glance.
The fact is that some components may not be made in the form of expansion cards, but may be built-in(integrated) into the motherboard or central processor.
In this case, additional chips are installed on the motherboard that perform the functions of a network and sound adapter. The video adapter is built (integrated) into the main chip of the motherboard.
In the photo, number 1 is the video adapter, number 2 is the network adapter, and number 3 is the sound adapter.
At the same time, expansion slots (number 4) remain on the motherboard for installing more functional components (if the built-in ones, for some reason, do not suit you).
In principle, it would be possible to make a separate lesson on internal structure of laptops and netbooks. But, essentially, it contains the same components as in a desktop computer, only these components are smaller and are mounted differently.
Each of the components listed in this IT lesson performs its task, but perhaps it is interesting to know which components most affect the speed of your computer?
Since most of the calculations are performed CPU, then it most affects the performance of the computer.
RAM The processor needs it to supply data and programs to perform calculations. Therefore, the amount of memory also significantly affects the performance of the entire computer.
If you need a computer for gaming or working with 3D graphics, then the speed of operation is of great importance video adapter.
But if the computer is used to surf the Internet, as well as with text documents, photographs, watch movies and listen to music, then you can get by with the slowest (but modern) video adapter, including one built into the motherboard or processor.
To reinforce the new information, there is a very interesting video that describes in simple language the purpose of computer components. Unfortunately, the comments are in English, but there is a translation with subtitles (use the pause to have time to read).
So, in the seventh IT lesson we got acquainted with internal device of the computer and briefly reviewed everything system unit components. For the Beginner level, this knowledge is quite enough to consciously work in most programs that you may need.
In the next lesson we will learn what other devices can be connected to the computer (external devices), it is called.
Copying is prohibited, but links can be shared:
The computer has the following main blocks:
A person exists in an “ocean” of information, he constantly receives information from the world around him using his senses, stores it in his memory, analyzes it through thinking and exchanges information with other people. A computer, just like a person, receives information, stores and processes it, and exchanges it with other computers. A computer is a tool that helps a person navigate this “ocean” of information.
Personal computer(PC) is a relatively inexpensive universal microcomputer designed for one user. Information is exchanged between individual computer devices via a highway connecting all computer devices.
Personal computers are usually designed based on the principle of open architecture:
1. Only the description of the operating principle of a computer and its configuration (a certain set of hardware and connections between them) are regulated and standardized. Thus, the computer can be assembled from individual components and parts designed and manufactured by independent manufacturers.
2. The computer is easily expanded and upgraded due to the presence of internal expansion slots into which the user can insert a variety of devices that meet a given standard, and thereby set the configuration of his machine in accordance with his personal preferences.
The system unit contains all the electronic components of the computer:
The main hardware component of a computer is the motherboard. The motherboard has an information exchange backbone, there are connectors for installing a processor and RAM, as well as slots for installing controllers for external devices.
The characteristics of the motherboard are:
Over the past few years, one of the hottest topics has been the topic of MP integration - whether it is necessary to embed video, sound, and other capabilities in MP. Most experienced users strongly oppose the integration of MPs, as it limits their choice and believe that integration should be carried out on MPs that are supplied to the “mass market”. On the other hand, manufacturers find MP integration quite attractive as it allows them to present a more functional product to the user and at the same time reduce the price of the product due to the reduction of several expansion slots and smaller PCBs. No matter what, the main task of manufacturers is to provide the user with as many features and functionality as possible along with their product. In the end, we will most likely witness the invention of special sockets where graphics chips will be inserted and thereby the video capabilities of a particular product will be improved, much the same thing we do today with the processor. Graphics memory will be built into the graphics chip in the MP or will be located in both. Modems, sound and LAN controllers will also be included. This will allow manufacturers to eliminate the ISA slot, as well as most PCI slots. USB and IEEE1394 devices will slowly replace the relatively slow serial, parallel, IDE and SCSI devices that are now most common.
The processor is implemented in hardware on a large integrated circuit (LSI). A large integrated circuit is not actually "large" in size and is instead a small flat semiconductor wafer, approximately 20x20mm, enclosed in a flat package with rows of metal pins (contacts).
The use of modern high technologies makes it possible to place on the processor LSI a huge number (42 million in the Pentium 4 processor) of functional elements (switches), the dimensions of which are only about 0.18 microns (1 micron = 10 -6 meters).
These elements form a complex structure, which allows the processor to process information (for example, adding numbers) at very high speeds. Modern processors are very fast; for example, the Pentium 4 processor can process information at a frequency of 1.5 GHz (perform 1.5 billion operations per second).
The central processor generally contains:
A computer system may have several processors running in parallel; such systems are called multiprocessor. In the characteristics of a computer, the processor is put in first place, since it largely determines the performance of the computer. Therefore, when purchasing, they first choose this one, and then select the remaining devices: chipset, RAM, motherboard, etc.
One of the main characteristics of the processor is clock frequency. The microprocessor performs certain operations (writing, reading, processing data) in precisely allotted units of time (cycles), which is necessary to synchronize the process. Information processing is faster, the higher the clock frequency. It is measured in MHz (MHz, megahertz) and GHz (GHz, gigahertz). Distinguish processor core frequency(internal) and system bus frequency(external).
The external clock frequency (processor bus frequency) is generated by the pulse generator on the motherboard and determines the performance of the CPU core. The processor bus carries out data exchange between the CPU, memory and other devices.
The internal clock speed determines to a large extent the speed of the processor. It indicates how many elementary operations (cycles) the microprocessor performs in one second. This frequency is indicated in the price lists of companies selling processors. This value is the product of the system bus frequency supplied from the quartz resonator by the internal multiplier. This coefficient is determined by applying voltage to certain pins of the CPU. For example, 266*5=1330 MHz.
Name "operative" This memory was obtained because it works very quickly, but the data it contains is saved only while the computer is turned on. Often the designation RAM (random access memory, that is, random access memory) is used for RAM. Since the elementary unit of information is a bit, RAM can be considered as a certain set of elementary cells, each of which is capable of storing one information bit.
RAM, intended for storing information, is manufactured in the form of memory modules. Memory modules are plates with rows of contacts on which memory LSIs are placed. Memory modules can differ in size and number of contacts (SIMM or DIMM and DDR RA). The most important characteristic of RAM modules is speed, i.e. the frequency with which operations of writing or reading information from memory cells occur. Modern memory modules provide frequencies of 133 MHz and higher.
In random access memory, an elementary memory cell is a capacitor capable of storing an electrical charge for a short period of time, the presence of which can be associated with an information bit. Simply put, when writing a logical one to a memory cell, the capacitor is charged, and when writing a zero, it is discharged. When reading data, the capacitor is discharged through the reading circuit, and if the capacitor charge was not zero, then the output of the reading circuit is set to a single value.
In addition, since the capacitor is discharged during reading, it must be charged to its previous value. Therefore, the reading process is combined with recharging the capacitors (charge regeneration). If the cell is not accessed for a long time, then due to leakage currents, the capacitor is discharged over time and information is lost. As a result, memory based on an array of capacitors requires constant periodic recharging of the capacitors (which is why it is called dynamic).
To compensate for charge leakage, regeneration is used, based on periodic cyclic access to memory cells, since each such access restores the previous charge of the capacitor. Regeneration in the microcircuit occurs simultaneously along the entire row of the matrix when accessing any of its cells, that is, it is enough to cycle through all the rows.
Each memory element is defined by its address. Memory elements are combined in a housing microcircuits, and the latter, in turn, are placed on special small printed circuit boards (modules). These boards are inserted into slots specially designed for them on the motherboard, so-called banks. A bank is understood as one or more connectors combined into a logical unit.
The main characteristics of RAM are:
The main characteristic of memory is its throughput, that is, the maximum amount of data that can be read from memory or written to memory per unit time. It is this characteristic that is directly or indirectly reflected in the name of the memory type.
A computer's RAM consists of a large number of cells, each of which can store a certain amount of information. In modern personal computers, the number of memory cells reaches tens of millions.
The most important characteristic of a computer as a whole is its performance, i.e. the ability of a computer to quickly process large amounts of information. Computer performance is largely determined by the speed of the processor, as well as the amount of RAM and the speed of access to it. M), in terms of speed, information capacity, etc.
To speed up access to RAM, modern high-speed computers use special “ultra-fast” (“ultra-RAM”) memory, which is called cache memory and is like a buffer between a very fast processor and a fairly slow RAM. It began to be used starting with 486 computers and is now used in all modern PC models.
The cache memory is controlled by a special device - controller, which, by analyzing the program being executed, tries to predict what data and commands the processor will most likely need in the near future, and pumps them into the cache memory. In this case, both “hits” and “misses” are possible. In case of a hit, that is, if the necessary data is pumped into the cache, it is retrieved from memory without delay. If the required information is not in the cache, then the processor reads it directly from RAM. The ratio of hits to misses determines the effectiveness of caching.
Modern microprocessors have a built-in cache memory, the so-called first level cache (internal cache memory), which is designated L1 (Level 1) and has a size of about 64-128 KB. Its purpose is to coordinate the speed of the processor and external cache memory.
In addition, there is a second level cache (external cache), which is designated L2 (Level 2) and has a capacity of 128 KB to 256 KB and higher. The main task of external cache memory is to organize data exchange between the processor and memory with the least number of waiting cycles. There are currently three L2 cache layouts:
Persistent memory(ROM, English ROM, Read Only Memory) - non-volatile memory, used to store data that will never require changes. The memory contents are specially “hardwired” into the BIOS chip during its manufacture for permanent storage. ROM can only be read.
BIOS(Basic Input/Output System) - this is the basic input/output system. BIOS is a complex system consisting of a large number of utilities designed to automatically recognize the equipment installed on a computer, configure it and check its operation.
This system includes various input-output programs that provide interaction between the operating system, application programs on the one hand, and devices included in the computer (internal and external) on the other.
Initially, BIOS was intended to test the computer when turned on - the so-called POST (Power On Self Test) or BIST (Built In Self Test) procedures, and ensure subsequent loading of the OS. This is true for PCs of the i8086, i8088 families and for a significant part of the 80286 family.
Currently, BIOS is a complex system consisting of a large number of utilities designed to automatically recognize the equipment installed on a computer, configure it and check its operation. BIOS programs are usually called through software or hardware interrupts. When you turn on the computer, the BIOS tests (POST - Power-On-Self-Test) system components - processor, memory, disk drives (both hard and floppy drives), keyboard, etc.
BIOS is implemented in the form of a chip installed on the computer motherboard. Note that the name ROM BIOS is currently not entirely fair, because “ROM” involves the use of read-only memory devices (Read Only Memory), and reprogrammable memory devices are currently used mainly to store BIOS codes. The most promising BIOS for system storage is flash memory(replaceable memory cards). It allows you to modify functions to support new devices connected to your computer.
Media using flash memory constitute the largest class of portable digital storage media and are used in the vast majority of modern digital devices. Various types of flash memory cards are increasingly used in digital cameras, PDAs, audio players, mobile phones and other portable electronic systems.
The use of flash memory chips makes it possible to create miniature and very lightweight, non-volatile, removable memory cards that also have low power consumption. An important advantage of flash memory cards is also their highest reliability due to the absence of moving parts, which is especially critical in the case of external mechanical influences: shocks, vibrations, etc.
The main disadvantages of such media are the rather high price of the flash memory cards themselves and the high specific cost of the data stored on them, although there is currently a trend towards a significant reduction in prices for replaceable flash memory cards.
The most common types of flash cards today are CompactFlash (CF), SmartMedia (SM), Secure Digital (SD), MultiMediaCard (MMC) and Memory Stick (MS), which differ from each other in interfaces, dimensions, read/write speed and maximum possible capacity.
At the physical level, flash memory of various standards has much in common, and first of all this is the architecture of the memory array and the design of the memory cell itself. The fundamental difference between flash memory and RAM memory is that it is non-volatile memory capable of storing information for an unlimited time in the absence of external power.
In principle, there are several types of non-volatile memory, and in this sense, flash memory is just one of its varieties. The BIOS system is inextricably linked with CMOS RAM (CMOS - Complementary Metal Oxide Semiconductor).
CMOS (semi-permanent memory) is a small area of memory for storing computer configuration parameters, which is regulated using the CMOS Setup Utility. Has low power consumption. The contents of CMOS memory do not change when the computer's power is turned off because it uses a special battery to power it.
Video memory- a type of random access memory in which encoded images are stored. This memory is organized in such a way that its contents are available to two devices at once - the processor and the display. Therefore, the image on the screen changes simultaneously with the update of the video data in memory.
The speed at which information enters the screen, and the amount of information that leaves the video adapter and is transmitted to the screen, all depend on three factors:
Permission determined by the number of pixels on the line and the number of lines themselves. Therefore, on a display with a resolution of 1024x768, typical of systems using the Windows OS, an image is formed each time the screen is updated from 786,432 pixels of information.
Usually screen refresh rate measured in hertz (Hz), or cycles per second. The consequence of screen flickering is visual strain and eye fatigue when looking at the image for a long time. To reduce eye fatigue and improve image ergonomics, the screen refresh rate should be at least 75 Hz.
The number of colors that can be reproduced, or color depth is the decimal equivalent of the binary value of the number of bits per pixel. So, 8 bits per pixel is equivalent to 28 or 256 colors, 16-bit color, often called simply high-color, can represent more than 65,000 colors, and 24-bit color, also known as true color, can represent 16.7 million colors. . To avoid confusion, 32-bit color usually means displaying true color with an additional 8 bits used to provide 256 degrees of transparency. Thus, in a 32-bit representation, each of the 16.7 million true colors has an additional 256 degrees of transparency available. Only high-end systems and graphics workstations have this color representation capability.
Previously, desktop computers were mainly equipped with 14-inch monitors. VGA resolution of 640x480 pixels covered this screen size quite well. Once the size of the average monitor increased to 15 inches, the resolution increased to 800x600 pixels. As the computer increasingly becomes a visualization tool with ever-improving graphics, and graphical user interfaces (GUIs) become the standard, users want to see more information on their monitors.
17-inch monitors are becoming standard equipment for Windows-based systems, and a resolution of 1024 x 768 pixels adequately fills a screen of that size. Some users use a resolution of 1280x1024 pixels on 17 inch monitors.
A modern graphics subsystem requires 1 Megabyte of memory to provide a resolution of 1024x768. Although only three-quarters of this amount of memory is actually needed, the graphics subsystem typically stores cursor and shortcut information in off-screen memory for quick access. Memory bandwidth is determined by the ratio of how many megabytes of data are transferred to and from memory per second of time. A typical resolution of 1024x768, with 8-bit color depth and a screen refresh rate of 75 Hz, requires memory bandwidth of 1118 megabytes per second. Adding 3D graphics processing functions requires increasing the size of the available memory on board the video adapter to 4 megabytes. Additional memory beyond that required to create the image on the screen is used for the z-buffer and texture storage.
Hard magnetic disks are several dozen disks placed on one axis, enclosed in a metal case and rotating at a high angular speed. Due to the much larger number of tracks on each side of the disks and the large number of disks, the information capacity of hard disks can be tens of thousands of times greater than the information capacity of floppy disks.
Like a floppy disk, the working surfaces of platters are divided into circular concentric tracks, and the tracks into sectors. The read-write heads, along with their supporting structure and disks, are enclosed in a hermetically sealed housing called data module. When a data module is installed on a disk drive, it automatically connects to a system that pumps purified cooled air.
The surface of the platter has a magnetic coating only 1.1 microns thick, as well as a layer of lubricant to protect the head from damage when lowering and raising on the go. When the platter rotates, an air layer is formed above it, which provides an air cushion for the head to hover at a height of 0.5 microns above the disk surface.
Each head consists of two elements: a recording head and a magnetoresistive read head. The recording head is a miniature electromagnet consisting of a core and an inductor. In the section between the poles of the core, a magnetic field of the desired direction is created, which magnetizes the working surface of the disk, creating a magnetic domain with a given direction of magnetization.
The reading head is a magnetoresistive (MR) element that changes its resistance in the presence of a magnetic field.
Floppy drives
Floppy disk drives work with flexible magnetic disks (FMD) or simply floppy disks. Floppy disk, floppy disk
- a device for storing small amounts of information, which is a flexible plastic disk in a protective shell. Used to transfer data from one computer to another.
A floppy disk consists of a round polymer substrate coated on both sides with a magnetic oxide and placed in a plastic package, the inner surface of which is coated with a cleaning coating. The packaging has radial slots on both sides through which the drive's read/write heads gain access to the disk. concentric paths (tracks), which are divided into sectors. The number of tracks and sectors depends on the type and format of the floppy disk. A sector stores the minimum amount of information that can be written to or read from disk. The sector capacity is constant and amounts to 512 bytes.
A floppy disk can store from 360 Kilobytes to 2.88 Megabytes of information. Currently, floppy disks with the following characteristics are used: diameter 3.5 inches (89 mm), capacity 1.44/2.88 MB, number of tracks 80, number of sectors on tracks 18. Previously, floppy disks with a diameter of 5.25 inches, capacity which was 360 KB or 1.2 MB.
The floppy disk is installed in a floppy-disk drive, automatically fixed in it, after which the drive mechanism spins up to a rotation speed of 360 min -1. The floppy disk itself rotates in the drive, the magnetic heads remain motionless. The floppy disk rotates only when it is accessed. The drive is connected to the processor through a floppy disk controller.
Today, despite the widespread use of 3.5-inch floppy disks, they are gradually becoming outdated and floppy disk drives are no longer used in some modern PC models.
Laser drives (CD-ROM and DVD-ROM) use the optical principle of reading information. In appearance, both the drives themselves and the disks for CD-ROM and DVD-ROM are practically the same.
Operating principle optical disk drive is as follows: A precisely focused laser beam is reflected from the surface of a plastic disk. Information is recorded in the form of indentations on a spiral track. The reflected modulated light enters the photodetector and is then converted into a standard signal. On the disk, data is recorded on a very narrow (100 times thinner than a human hair) spiral track, the total length of which is 5 km. Any disc has a transparent polycarbonate backing, which gives it rigidity, a reflective metal layer and a protective layer of acrylic plastic (the label is printed on it). Laserdisc technology is evolving in several directions. These are CD and DVD media.
Information on a laser disc is recorded on one spiral-shaped track (like on a gramophone record), containing alternating sections with different reflectivity.
Controllers Controller(adapter)
- a device that connects the internal and external devices of a computer with the central processor, freeing the processor from directly controlling the operation of this equipment. Controllers exist for all devices not located on the motherboard. Let's look at the most important and frequently used controllers: Video card (video adapter, video controller)
is an electronic board that processes video data (text and graphics) and controls the operation of the display: it sends ray brightness control signals and image scanning signals to the display. Video controller
is responsible for outputting images from video memory, regenerating its contents, generating scanning signals for the monitor and processing requests from the central processor. To avoid conflicts when accessing memory on the part of the video controller and the central processor, the former has a separate buffer, which is filled with data from the video memory when the CPU is not accessing it. If the conflict cannot be avoided, the video controller has to delay the CPU's access to video memory, which reduces system performance; To eliminate such conflicts, a number of cards use so-called dual-port memory, which allows simultaneous access by two devices.
Many modern video controllers are streaming - their work is based on creating and mixing together several streams of graphic information. Typically this is the main image, overlaid with the image of the hardware mouse cursor and a separate image in a rectangular window. A video controller with streaming processing, as well as hardware support for some standard functions, is called an accelerator or accelerator, and serves to offload the CPU from routine operations of image formation. A video card consists of three main devices: memory, DAC and ROM. used to store images. The maximum possible full resolution of the video card depends on its volume - A x B x C, where A is the number of pixels horizontally, B - vertically, and C is the number of possible colors of each pixel. For example, for a resolution of 640x480x16 256 kb is enough, for 800x600x256 - 512 kb, for 1024x768x65536 (another designation is 1024x768x64k) - 2 MB, etc. Since an integer number of bits are allocated to store colors, the number of colors is always a power of two (16 colors - 4 bits, 256 - 8 bits, 64k - 16, etc.).
DAC(digital-to-analog converter, DAC) is used to convert the resulting data stream generated by the video controller into color intensity levels supplied to the monitor. Many modern monitors use an analog video signal, so the possible color range of the image is determined only by the DAC parameters. Most DACs have 8x3 resolution - three channels of primary colors (red, blue, green, RGB) with 256 brightness levels for each color, which gives a total of 16.7 million colors. Usually the DAC is combined on one chip with a video controller.
Video ROM- a permanent storage device in which video BIOS, screen fonts, service tables, etc. are recorded. The ROM is not used directly by the video controller - only the central processor accesses it, and as a result of its execution of programs from the ROM, calls are made to the video controller and video memory. ROM is necessary only for the initial launch of the adapter and operation in MS DOS mode; Operating systems with a graphical interface do not use ROM to control the adapter.
Audio adapter(Audio card or sound card) is a special electronic board that allows you to record sound, play it back and create it in software using a microphone, headphones, speakers, built-in synthesizer and other equipment.
The audio adapter contains two information converters:
The audio adapter can be divided into four more or less independent blocks:
1. Digital recording/playback unit, also called the digital channel, or path, of the card. Performs analog->digital and digital->analog conversions in program transfer mode or via DMA. It consists of a node that directly performs analog-to-digital conversions - ADC/DAC (international designation - coder/decoder, codec), and a control node. The ADC/DAC is either integrated into one of the card's chips, or a separate chip is used (AD1848, CS4231, CT1703, etc.). The quality of digitization and sound reproduction largely depends on the quality of the ADC/DAC used; it depends no less on the input and output amplifiers.
2. Synthesizer block. Built either on the basis of FM synthesis chips OPL2 (YM3812) or OPL3 (YM262), or on the basis of WT synthesis chips (GF1, WaveFront, EMU8000, etc.), or both. It works either under the control of a driver (FM, most WT) - software implementation of MIDI, or under the control of its own processor - hardware implementation. Almost all FM synthesizers are compatible with each other, but various WT synthesizers are not. Most WT synthesizers contain built-in ROM with a standard set of General MIDI instruments (128 melodic and 37 percussion instruments), as well as RAM for loading additional digitized sounds that will be used when performing music.
3. MPU block. Receives/transmits data via an external MIDI interface connected to the MIDI/Joystick connector and the connector for MIDI daughter cards. Usually more or less compatible with the MPU-401 interface, but most often requires software support.
4. Mixer block. Carries out level regulation, switching and mixing of analog signals used on the card. The mixer includes preliminary, intermediate and output amplifiers for audio signals.
Network card (network adapter) is an expansion card that is inserted into the connector of the computer's motherboard, which is used to connect the computer to the network. Network cards are characterized by their:
Modem(derived from the words MODulator/DEMOdulator) is a device for receiving and transmitting information over telephone communication lines.
How it works: As we know, data in a computer is stored digitally. And the telephone lines through which data is exchanged are mostly analog. Thus, to convert digital data into analog, the modem uses special digital-to-analog and analog-to-digital converters (modulators/demodulators). The mode of operation when data is transmitted in only one direction is called half duplex. Both computers can simultaneously exchange information in both directions. This mode of operation is called full duplex, or simply full duplex.
Analog signals are modulated, i.e. changes in their characteristic characteristics (frequency, phase, amplitude). This modulated signal is called a carrier. The modulation speed is measured in units of baud per second, and the amount of information transmitted (connection speed) is measured in bits per second (BPS - Bits Per Second). According to modern standards, up to 4 bits of information are transmitted per modulation, and for digital communication channels the baud number is equal to the number of bits per second. A unit of information transmitted in one modulation is called a character. To increase the amount of transmitted information, phase and amplitude modulation are used. From here came another unit of information measurement - the number of transmitted characters per second (CPS), i.e. the amount of useful information transmitted.
All modern modems are built according to one functionally similar scheme. They consist of a main processor, random access memory, read only memory, modulator/demodulator, telephone line conditioner and built-in speaker.
The main processor is responsible for executing commands, buffering and processing data (encoding/decoding, compression/decompression, etc.), as well as controlling the signal processor. A digital signal processor (DSP - Digital Signal Processor), together with a modulator/demodulator, deals with signal operations, frequency division, etc. ROM stores microinstruction sets for the main and signal processors (firmware).
Modern modems use multi-programmable ROM, which allows you to quickly change firmware when new features appear. RAM is used as temporary memory when operating the main and signal processors. Line matching schemes use a transformer, a special device for recognizing the ringing signal, a line relay and a dialing relay (relays have recently been replaced by silent electronic keys). To protect the modem from line surges, each modem is equipped with an attenuator input device. The built-in speaker serves for audio monitoring of the status when dialing and connecting.
Exist external and internal modems. Internal modem (soft modem)- this is a board inserted inside the system unit and located in the ISA, PCI, AMR, CNR slots. The internal modem is powered by the computer's motherboard and uses computer resources (processor, memory, etc.), so it costs less than an external modem. Internal modems are divided into WinModem, where the controller functions are performed by a special driver, and SoftModem, in which, in addition to the controller, there is no digital signal processor.
External modem- a peripheral device that connects to a COM or USB port. Such modems have their own power supply, as well as various regulators and indicators. The vast majority of external modems connect to the computer via a serial interface called RS-232C or USB. To do this, you need to connect the cable to the serial port (COM port) of the computer.
In addition to conventional modems, now quite common fax modems, which in addition to the main functions also perform receiving and sending faxes, i.e. transmission or reception of graphic and text black and white images over telephone lines.
power unit converts alternating mains voltage into direct voltage of various polarities and magnitudes necessary to power the system board and internal devices. The main characteristic of BP is power. The standard power supply of a modern computer is 300 W or 400 W.
The task of the power supply is to convert the mains voltage of 220 W (110 W) into the supply voltage of the computer’s structural elements: +12 V at a current of 3.5–10 A to power the motors of devices (floppy drive, hard drive, CD-ROM, etc.) and +5 V at a current from 10A to 20A to power all electronic circuits of the computer. The ATX standard power supply differs significantly from conventional AT units in its electrical interface. The ATX unit provides an additional +3.3V to power processors and RAM modules. There is also an additional “standby” low-power source with a load current of up to 10 mA with a voltage of +5V.
Power supply contains fan, creating circulating air flows to cool the system unit. In light of the rapidly growing PC power, almost every board or chip began to have fans and radiators. For a processor, a fan and a radiator (cooler) have long become standard. Power is supplied from a single power supply to all circuits and devices of the system unit.
Port- This is a connector through which you can connect the computer’s motherboard to an external device. Ports for connecting external devices. To connect peripheral equipment, as well as communicate with other computers, the system unit has connectors for various ports.
Serial ports transmit electrical impulses carrying information in machine code, one after another. Serial ports are designated as COM1 and COM2, and are implemented in hardware using 25-pin and 9-pin connectors, which are located on the rear panel of the system unit. Serial ports usually connect a mouse and a modem.
Parallel port transmits simultaneously 8 electrical impulses carrying information in machine code. The parallel port is designated as LPT, and is implemented in hardware as a 25-pin connector on the rear wall of the system unit. The parallel port has a higher transfer rate than parallel ports and is used to connect a printer.
USB port. In recent years, the USB port (Universal Serial Bus) has become widespread, which provides high-speed connection to the computer of several peripheral devices (scanners, digital cameras, etc.).
SCSI adapters.To connect joysticks designed to control games, a special Game port (game port) is used, which is usually located on the sound card. Monitor
Monitor
is a universal information output device and connects to a video card, which is installed in the motherboard expansion slot in the system unit.
The image in computer format (in the form of sequences of zeros and ones) is stored in video memory located on the video card. The image on the monitor screen is formed by reading the contents of the computer's video memory and displaying it on the screen. The frequency of image reading affects the stability of the image on the screen. In modern monitors, image updating usually occurs at a frequency of 75 or more times per second, which ensures comfortable perception of the image by the computer user (a person does not notice the flickering of the image). For comparison, we can recall that the frame rate in cinema is 24 frames per second. Desktop computers typically use monitors
The image on a CRT monitor screen is created by a beam of electrons emitted by an electron gun. This beam (a beam of electrons) is accelerated by high electrical voltage (tens of kilovolts) and falls on the inner surface of the screen, coated with a phosphor (a substance that glows under the influence of an electron beam).
The beam control system makes it run line by line across the entire screen (creates a raster), and also regulates its intensity (accordingly, the brightness of the phosphor dot). The user sees the image on the monitor screen, because A phosphor emits light rays in the visible part of the spectrum. In order for electrons to reach the screen unhindered, air is pumped out of the tube, and between guns and screen high electrical voltage is created, accelerating electrons . Placed in front of the screen in the path of the electrons mask
- a thin metal plate with a large number of holes located opposite the phosphor points. The mask ensures that electron beams hit only the phosphor points of the corresponding color. Monitors may have different screen sizes. Screen diagonal size is measured in inches (1 inch = 2.54 cm) and is usually 14, 15, 17 or more inches.
However, the monitor is also a source of high static electrical potential, electromagnetic radiation and radiation, which may have adverse effects on human health. A necessary characteristic of monitors is their compliance with sanitary and hygienic requirements, which are stated in the international safety standard (MPR II). When setting up your computer, it is useful to remember that electromagnetic and other radiation is most intense at the rear of the monitor case. Laptop and pocket computers use flat-panel liquid crystal (LCD) monitors. Recently, such monitors have begun to be used in desktop computers. Advantage
LCD- this is a special state of some organic substances in which they have fluidity and the ability to form spatial structures similar to crystalline ones. Liquid crystals can change their structure and light-optical properties under the influence of electrical voltage. By changing the orientation of groups of crystals using an electric field and using substances introduced into a liquid crystal solution that can emit light under the influence of an electric field, it is possible to create high-quality images that convey more than 15 million color shades.
In LCD monitors, the image is formed using a matrix of pixels consisting of liquid crystals. This is where the abbreviation LCD (Liquid Crystal Display) comes from, which stands for liquid crystal display. The use of liquid crystals as the main element of the image is not accidental: they are capable of changing the direction of polarization of light passing through them. And if an external voltage is applied to the crystal, the direction of polarization will change. This allows you to control the intensity of transmitted light. Polarizers are installed on both sides of the crystal, so that their axes are located at right angles to each other. A beam of light, passing through the first of them, will become linearly polarized.
Then, in the liquid crystal cell, the plane of polarization of light will rotate through a certain angle, the magnitude of which will depend on the applied voltage. Finally, the role of the second polarizer is to regulate the amount of transmitted radiation; if the angle between the direction of its axis and the plane of polarization of light is gradually changed from O to 90 °, then the absorption of radiation will increase. This way you can control the light intensity (pixel brightness). As is known, to form a color image it is necessary to have pixels of three colors: red, green and blue. Since liquid crystals are absolutely transparent, they cannot influence the color characteristics of the radiation. For this purpose, filters are used that isolate the necessary spectral components from the “white” radiation of backlight lamps.
Serves to enter information into the computer and supply control signals. It contains a standard set of alphanumeric keys and some additional keys - control and function keys, cursor keys, as well as a small numeric keypad.
Cursor- a glowing symbol on the monitor screen indicating the position at which the next character entered from the keyboard will be displayed. All characters typed on the keyboard are immediately displayed on the monitor at the cursor position.
Most common today 101-key keyboard with QWERTY key layout(read “querti”), named after the keys located in the upper left row of the alphanumeric part of the keyboard:
This keyboard has 12 function keys located along the top edge. Pressing a function key results in sending not just one character to the computer, but a whole set of characters.
Function keys can be programmed by the user. For example, in many programs, to get help (hints) the key is used F1, and to exit the program - the key F10.
The control keys have the following purposes:
Small numeric keypad used in two modes - number input and cursor control. These modes are switched using the key Num Lock. The keyboard contains a built-in microcontroller, which performs the following functions:
The keyboard has built-in buffer- small intermediate memory where entered characters are placed. If the buffer overflows, pressing a key will be accompanied by a sound signal - this means that the character was not entered (rejected).
The keyboard is supported by special programs built into the BIOS, as well as keyboard driver, which provides the ability to enter Russian letters, control the speed of the keyboard, etc.
Nowadays they are also widely used wireless keyboards. As the name suggests, wireless keyboards transmit information to the computer not via a cable, but via radio waves or using infrared radiation. In addition to the obvious advantages, wireless keyboards also have disadvantages, which include, for example, the need to use an autonomous power source.
Manipulators are special devices that are used to conveniently control the cursor. Manipulators include the following devices:
1. looks like a small box that fits completely in the palm of your hand. The mouse is connected to the computer with a cable through a special block - an adapter, and its movements are converted into corresponding cursor movements on the display screen. At the top of the device there are control buttons (usually there are three, with the scroll or scroll wheel often playing the role of the third button), which allow you to set the start and end of movement, select menus, etc.
Classifications of mice:
2. - a small box with a ball built into the upper part of the body. The user rotates the ball with his hand and moves the cursor accordingly. Unlike a mouse, a trackball does not require free space near the computer; it can be built into the body of the machine. Most often it is used as a replacement for a mouse, especially for working with graphics.
In optical-mechanical manipulators, the main working element is a massive ball (metal, covered with rubber). For a mouse, it rotates when its body is moved along a horizontal surface, and for a trackball, it rotates directly by hand.
The rotation of the ball is transmitted to two plastic shafts, the position of which is read with great accuracy by infrared optocouplers (i.e., light emitter-photodetector pairs) and then converted into an electrical signal that controls the movement of the mouse pointer on the monitor screen. The main “enemy” of the mouse is pollution, and the way to combat it is to use a special “mouse” mat.
Manipulators have one, two or three control buttons, which are used when working with the graphical interface of programs. Currently, mice have appeared with an additional button, which is located between the two large main buttons. It is designed to scroll up or down an image, text or Web page that does not fit entirely on the screen.
Manipulators can connect to a computer in three different ways: using a serial COM port, a special small round five-pin PS/2 connector, and a universal USB port. 
3. . Another coordinate input device is the TouchPad (touchpad). This name can be translated into Russian as “touch panel”.
The touchpad is a rectangular panel that is sensitive to finger pressure.
The touchpad plays the same role as a mouse, but is a smaller, less spatially movable input device that is ideal for laptop computers. Sometimes the touchpad is built directly into the desktop keyboard. By placing a finger on the touchpad surface and moving it, the user can maneuver the cursor in the same way as using a mouse. Pressing the touchpad surface is equivalent to pressing a mouse button.
4. - usually this is a pen-rod, the deviation of which from the vertical position leads to the movement of the cursor in the corresponding direction on the monitor screen. Often used in computer games. Some models have a pressure sensor mounted in the joystick. In this case, the harder the user presses the handle, the faster the cursor moves across the display screen.
Joysticks are divided into two main classes - with or without proportional control. The simplest joysticks
(without a handle or with it) the principle of operation is completely similar to the keys. They have mechanical internal contacts that operate to open or close. Playing on them is much worse compared to a simple keyboard, because... It takes longer to move the handle than to press a button. But this statement is only true for a relatively experienced player who is accustomed to playing the keyboard. For a beginner, even such a joystick would be preferable, because... allows you to play more or less tolerably right away, without a lot of getting used to. are analog devices based on changes in resistance as physical coordinates change. Based on their design, modern joysticks are divided into five main categories:
These are devices located outside the system unit and are not mandatory when working with a computer, but rather complement and expand its capabilities. 
1. Printer(from the English printer - printer) - a device designed to output text or graphic information prepared on a PC onto paper or film. Main characteristics of printers:
The main printing technologies are:
Matrix. Operating principle: a dot matrix printer prints using an ink ribbon; The ink from the tape is transferred to the media using retractable pins located in the matrix. A vertical row (or two rows) of needles, or hammers, “punches” the dye from the ribbon directly into the paper. There are usually 9, 18 or 24 pins. Printing speed is 25-150 characters/s.
Jet. Inkjet printers are impactless printing devices. In inkjet printers, the print head moves only in a horizontal plane, and the paper is fed vertically. The nozzles (channel holes) on the print head through which ink is sprayed correspond to the "impact" needles. The number of nozzles for different printer models, as a rule, can vary from 12 to 64. The maximum resolution, as a rule, reaches a value of about 360 dpi.
Operating principle: there is a nozzle that sprays ink along the contour of the character. When sharply heated, an ink vapor bubble is formed, which tries to push the required portion (drop) of liquid ink through the nozzle outlet.
Text printing speed is 5-150 characters/s (1-3 ppm). There are one-color, three-color and four-color. The printing quality is high, comparable to laser, and the cost of printing is much lower, especially color. The disadvantages include the fact that the quality depends on the paper, as well as quite expensive consumables.
Laser. Operating principle: the laser generates a thin beam of light, which, reflected from a rotating mirror, forms an electronic image on a photosensitive photoreceiving drum, capable of changing the electrical charge of a point under the influence of the laser beam that hits it. The drum is first given a static charge. The areas illuminated by the laser are discharged. Once the image on the drum is completed and it is coated with toner, the fed sheet is charged so that the toner from the drum is attracted to the paper. After this, the image is fixed on it by heating the toner particles to the melting point. The final fixation of the image is carried out by special rubber rollers that press the molten toner onto the paper.
2. . The scanner is used for optical input into a computer and conversion into digital form of images (photos, drawings, slides), as well as text documents. The scanned image is illuminated with white light (black and white scanners) or three colors (red, green and blue). The reflected light is projected onto a line of photocells, which moves, sequentially reads the image and converts it into a computer format.
Text recognition systems allow you to convert scanned text from a graphic format to a text format. Such systems are capable of recognizing text documents in different languages, presented in different forms (for example, tables) and with different print quality (from typewritten documents).
Exist flatbed and handheld scanners. Flatbed scanners may come with a special slide module designed for scanning slides. The resolution of scanners is 600 dpi (dot per inch) and higher, i.e. on a strip of image 1 inch long, the scanner can recognize 600 or more dots.
3. Scanners are connected to a computer in various ways: using SCSI adapters, to parallel or USB ports of the computer. Multimedia devices
. The term "multimedia" is formed from the words "multi" - many, and "media" - environment, medium, means of communication, and to a first approximation it can be translated as "multi-medium" Multimedia
is a collective concept for various computer technologies that use several information media, such as graphics, text, video, photography, moving images (animation), sound effects, high-quality sound. Multimedia technology consists of two main components - hardware and software. Multimedia devices - These are PC devices that directly serve to work with sound, graphic and video information. Multimedia computer
is a computer equipped with hardware and software that implements multimedia technology.
Digital cameras and TV tuners. In recent years, digital cameras (camcorders and cameras) have become increasingly widespread. Digital cameras allow you to receive video images and photographs directly in digital (computer) format. 
Digital video cameras can be permanently connected to a computer and record video images on a hard drive or transmit them over computer networks.
Digital cameras allow you to take high-quality photographs, which are stored using special memory modules or very small hard drives. Recording images to your computer's hard drive can be done by connecting the camera to the computer's USB port.
If you install a special board (TV tuner) into your computer and connect a television antenna to its input, you will be able to watch television programs directly on the computer.
Description of the internal structure of a computer (for beginners).
A home or office computer (in the common sense - an ordinary computer) consists of a system unit and peripheral devices (monitor, keyboard, mouse, scanner, printer, etc.).
I won’t describe what a monitor, printer and keyboard with a mouse look like, but will immediately move on to describing the insides of the main component of the computer - the system unit.
We remove the side cover of the system unit and see the following picture:
Photo of the internal structure of the computer
1. Frame- a very important part of the computer. They come in different sizes and form factors. The choice of system unit case should be approached carefully. In principle, the larger and heavier the case, the better - it will be easier to ensure good cooling and low noise levels. Buy cases only from well-known brands, for example: InWin, Thermaltake, Chieftec, Asus, etc.
2. power unit- one of the most important components of the computer system unit. You can save on anything, but not on the power supply. Oddly enough, the quality of the power supply can be indirectly determined by weight - the heavier, the better. Take a cheap, nameless power supply in one hand, and an expensive branded one in the other, and you will understand everything. High-quality radiators and transformers are quite heavy. The power supply provides power to all components of the system unit, and the quality of this power has a significant impact on the health of all components. A low-quality power supply can cause unstable computer operation and even burn out expensive components. Branded cases are usually equipped with fairly high-quality power supplies. When choosing a power supply, you also need to pay attention to its power, for example, 300 W will be enough for an office computer, but 500 W may not be enough for a gaming computer.
3. Microprocessor(CPU - central processing unit) with cooling radiator and fan. The microprocessor is the main computing device of the computer; it is the one that executes the commands that make up the programs in sequence. The performance of a computer largely depends on the speed of the processor. The speed of a processor is determined by the frequency at which it operates, the number of cores and its architecture. Now there are two main brands on the market: Intel and AMD. The choice of processor is determined by the tasks for which the computer is purchased. Top models are usually needed for games, video processing and similar tasks. (website)
4. Case fan. Necessary for creating air circulation inside the system unit: it usually works as a blower, removing warm air from the computer case and causing an influx of cold air from outside.
5. RAM modules. Random access memory (RAM - random access memory, RAM) is the high-speed memory of a computer. It is this memory that the processor works directly with. After turning off the computer, the information stored in it is erased. Taking into account the gluttony of modern programs, the rule is: the more RAM, the better. At the moment, the optimal amount of RAM will probably be 4-8 Gigabytes.
6. Video card(video adapter, video card, videocard, videoadapter) - processes and displays graphic information on the monitor. The video card has its own specialized graphics processor, which processes 2D/3D graphic information. This reduces the computational load on the central processing unit (CPU). For office applications, almost any video card is suitable (even one built into the motherboard), but for toys you will have to fork out more. I think you should choose a gaming video card after first deciding on the set of games you would like to play. When choosing a top-end video card, make sure that the power of your power supply is sufficient.
7. Modem. (Probably an obsolete device in Moscow)
8. LAN card. Through a network card, the computer connects to a local or global network (Internet). Nowadays, network cards are usually integrated into motherboards.
9, 10. CD or DVD drive(CD/DVD-ROM). There are both those who write and those who do not write. Read and write speeds may differ.
11. HDD(hard magnetic disk drive, harddisk, HDD) is a long-term memory device, the data is not erased when the power is turned off, the operating speed is much lower than that of RAM, and the capacity is much higher. All your installed programs, documents, music and movies are stored on your hard drive. Its capacity is measured in Gigabytes - the more the better, although 40-80 Gigabytes are enough for most office applications.
12. Motherboard- the main component of the system unit, because it combines all the listed devices and also contains additional components: network adapter, video card, sound card, input/output devices, etc.
When choosing components, you should make sure that they are compatible with each other. Don't skimp on the case and power supply - it's better to save on a video card and then buy a new one over time. It is also better to buy a motherboard “with a reserve” in order to upgrade the processor, memory, etc. in the future.
What does the system unit case hide behind?
A standard computer requires the following components:
In this article we will talk about the motherboard, processor, RAM, hard drive.
Read about the power supply, video card, sound card and disk drives.
Motherboard (system) board
Has a middle name: motherboard. It is often called simply “mother” because it provides communication between all the dissimilar elements of the system unit.
It is to the motherboard that the processor, hard drive, disk drives, video card, monitor, keyboard, mouse, printer, modem, etc. are connected.
To do this, there are connectors (or slots) on the board, some of which have an exit to the outside, while others do not. On the back wall of the system unit you can see connectors that come out of the computer and are intended for connecting external devices (keyboard, mouse, printer, monitor, etc.)
But those connectors on the motherboard that are not visible to us from the outside are used to “stick” into them the main parts that are responsible for the speed of the computer as a whole. The most important element that is attached to the board is CPU.
This is the brain of the computer. Its main characteristics are the bit capacity and clock frequency; the higher these indicators, the more powerful the processor. The speed of the computer depends on the frequency of the processor (number of operations per second). Frequency is measured in hertz.
Fan (cooler)
To prevent the processor from “boiling its brain” from hard work, they install it directly on top of it. fan. The fan tries very hard to cool the processor and, unfortunately, sometimes starts to buzz. The fan is also called cooler: from English “cool”, which should not be understood in the sense of “cool”, but as cool or cool.
Old computers did not have fans at all; they were not necessary. However, with the increase in computer power, some elements, consuming electric current, began to overheat and fail. There was a need to cool them, so fans appeared in system units. Now coolers can be installed inside the power supply, on the processor, or on the video card. An additional cooler can be installed on the system unit to cool the entire unit.
Random access memory (RAM)
In addition to the processor, the motherboard also contains a random access memory device (abbreviated RAM).
RAM in English is Random Access Memory or RAM for short. This memory is called operational. It is needed in order to store the information that the computer is working with at a given time. That is, it exists in order not to constantly “rummage” through a huge amount of data on the hard drive, but to work only with a certain volume, thereby reducing the time it takes to complete specified operations.
The more memory, the faster the computer runs. In addition, RAM is responsible for how many programs can be executed simultaneously.
There are several slots allocated for RAM on the motherboard, so over time, when it starts to run out, you can insert an additional one. Together with the original memory, they will make a good duet.
Hard drive (hard drive)
When you turn off the computer, all information from RAM is deleted. However, everything you need to save is always saved on hard disk (HDD) abbreviation for English Hard Disk Drive). You just need to remember to save your job!
A hard drive is often called a “screw” or a “vinch”. Located inside the system unit. This is a magic disk on which everything we need is recorded.
When you turn off the computer, all the information that was recorded on the hard drive remains. If you want, you can check it. The main thing is to have such a useful habit while working at the computer as periodically saving your work on the hard drive. As they say, “trust in God, but don’t make a mistake yourself.”
By the way, do you know where the name of the hard drive comes from – “hard drive”? In 1973, IBM created the first hard drive model, which had 30 tracks and 30 sectors. Therefore, the engineers who developed the disk, communicating with each other, used the short name “30-30”. This accidentally coincided with “Winchester 30/30” - the marking of the cartridge of the same company, which had a caliber of 0.30 inches, that is, 7.62 millimeters, and a standard charge of 30 grains (about 2 grams) of smokeless powder. Just as a rifle without a cartridge will not fire, a computer without a hard drive will not work.
External hard drive
Since 1973, the hard drive has been called “hard drive”.
In addition to the hard drive, which is located inside the system unit, if necessary, you can also connect the so-called “external hard drive” or “ external hard drive».
It can be connected to multiple computers and moved from place to place. It is especially relevant for laptops, where the resources of the built-in hard drive are usually small.
An external hard drive is also often used for archiving and backing up information on a computer.
The operating system, installed programs, documents, photos, music and movies are stored on the hard drive. HDD (hard disk) capacity is measured in Gigabytes. It is believed that the more, the better. As they say, there is never too much free space.
If you want to assemble a new system unit, if you want it to be made especially for you and not be like hundreds of others sold in stores, then the computer help center website will be happy to help you make your dream come true. By contacting our service, you can be sure of the reliability and durability of your future computer. After all, its assembly and configuration will be carried out by professionals with many years of successful experience!
