Computer case is different. Types of cases and power supplies of the system unit. What is a personal computer case and how to choose it

A little more about the hulls ...... Types of hulls.

Most often, saying "computer" many users mean the system computer block, in general they are right. By and large, a computer consists of a certain set of components: motherboard, processor with cooling system, random access memory, winchester, CD-ROM drive, keyboards, mice, etc. But in order for all computer components (like a PC, laptop, etc.) to successfully perform their functions and be protected from mechanical damage, they are placed in a special case. There are a lot of types and models of computer cases, and each type of computer case is designed to perform a specific task.
The case for any computer is a very important element that provides the placement and rigid fixation of all its devices, their cooling, providing them with power and protecting the rather fragile "insides" from the external environment.

There are several chassis standards - AT, ATX, micro ATX or Rack. ATX is more modern and the most common, most modern motherboards are designed specifically for it. It is characterized by easier access to the internal components of the computer (often without the use of a screwdriver), improved ventilation inside the case, the ability to install more full-size expansion cards, advanced power management options. Micro ATX is a small-sized option, well suited for compact base PCs with a minimum of expansion cards (minimum dimensions and affordable price). AT form factor cases are outdated and practically never used on this moment standard.
The current standard, ATX 2.03, is intended for motherboards that support processors from Intel Pentium 4 with a frequency of more than 3 GHz to this day. The main difference between the cases of the new standard is the use of high-power power supplies, a new arrangement of mounting holes for the motherboard and the use of additional attachment points for the processor cooling system.

The most widely used cases are of two types: desktop, located horizontally on the desktop and used for the most part in PC models manufactured by firms - "brands"; tower (tower-tower) - vertically located and massive type of case. Tower-type cases are subdivided, in turn, into micro-, mini-, midi- and big-tower, differing in the number of bays for 5.25 "drives: accordingly, micro-towers have 1 place for such drives, mini-tower - 2, midi-tower - 3 and big-tower - 4 or more.
Desktop

Most often, in a case of this type, from 2 to 3 devices of the 5.25 "format are placed horizontally and 2 - of the 3.5" format vertically, and one of them is with external access. Such cases take up quite a lot of space in the workplace, cannot always provide convenient access to internal devices, and do not always cope with the normal cooling of the processor and other components. All this suggests that the time of desktop-type cases is inexorably passing, and after all, the first PCs appeared in such cases, no one had heard of the tower at that time. But now desktops have absolutely no advantages over towers, but rather have significant disadvantages compared to towers.
Slim

The development of the idea of ​​miniaturization in relation to the computer field has given rise to such a miracle as the extremely integrated motherboards of the Flex-ATX format and their natural continuation - either Slim or Super Slim cases. In general, all cases are cramped, extremely uncomfortable, there are a minimum of opportunities, and the possibilities for modernization are very limited, but on the other hand, outwardly they look original and exclusive, but only such babies cost much more than full-featured machines, and are advertised by manufacturers - as inexpensive solutions for offices, and sometimes for home use.

mini tower

A rather small mini-tower case used to be the most widespread in the era of the dominance of Baby AT format "mothers", but now it is much less common, since problems can arise with the placement of full-size ATX motherboards in it, only small-sized ones remain. micro-ATX and flex-ATX boards. Such cases are most often used in PCs of the simplest configurations and are used as office machines or network terminals.

Midi (middle) tower

The most common case format today - midi (middle) -tower ATX, provides the use of a large number of drives and almost all types of motherboards with acceptable overall dimensions. Being a real "workhorse", optimally adapted to solve the widest range of tasks, cases of this type are used almost everywhere.

Big (full) tower

Being the largest, big-tower cases can accommodate motherboards of any size and the largest number of 5.25" devices, most often 4 to 6. In addition, they are usually equipped with high-power power supplies. The main area of ​​​​application of the cases is workstations , small servers and computers for advanced users.However, due to the increasing expansion of low-cost IDE RAID controllers into mainstream devices, the need for a large amount of disk storage space can make big-tower cases the most common devices, especially when you consider that modern high-speed hard drives heat up noticeably during operation, and devices mounted in 5-inch bays and designed to cool 3-inch HDDs have already begun to appear.

barebones

This is a simplified solution from the manufacturer, which includes everything for a quick computer assembly and only needs such variable components as a processor, memory and hard drive. The installation process of the latter takes a matter of minutes, and the computer is ready. As a rule, in such systems, manufacturers use their own proprietary components, so replacing the motherboard or adding some component can cause some difficulties. However, usually, such systems are used as mass corporate computers, or as a personal computer for a person who is not burdened with the needs for an upgrade.

This type of enclosure is used exclusively for installing a computer server hardware in telecommunication 19" racks and cabinets. These cases allow you to install more equipment than any other, including the installation of two power supplies for redundant power supply. These cases differ in their configuration and complete set for assembling servers for various purposes - from a data processing server to disk arrays large capacity.

Horizontal (dimensions are in millimeters):
- Desktop (533x419x152)
- FootPrint (406x406x152)
- SlimLine (406x406x101)
- UltraSlimLine (381x352x75)

Vertical (dimensions are in millimeters):
- Mini Tower (152x432x432)
- Midi Tower (173x432x490)
- Big Tower (190x482x820)
- SuperFullTower (different sizes)

Oddly enough, but often before buying a new computer, people do not always think about the size and type of future PC (form factor). Most often, this falls on the shoulders of sellers who are not always interested in the needs of the CUSTOMER, simply put - what kind of case was caught - they put it in that one ... However, often this parameter is important, both for the user and for the computer itself. How important is it? Many important parameters depend on the form factor of the PC (and on the correct choice of it, of course ...): ease of use, noise level, case temperature, and from this follow: the “health” of the components inside (primarily hard drives - which store your information - and this is known to be the highest value), convenience of work, etc., etc. … So, how to choose the right size system block future PC?

To begin with, I propose to consider them in more detail in turn:

In the beginning, it must be said that the dimensions of a PC are formed not only from the dimensions of the case itself. The size of the case must also correspond to the dimensions of the components - the motherboard in the first place, the video card, the power supply and other devices. For example, you cannot put system board ATX format into a miniTower case, or a GeForce 9800GTX video card into the same case - it just won't fit. And if it does fit, it will get so warm that a small space will not allow efficient heat removal, and overheating will threaten all devices ...

So, let's look at the form factors of cases - their size can be said to be directly proportional to the capabilities of the future PC, because. it determines the size of the components that can fit into it. And modern components are often large (for example, powerful video cards). Therefore, in a sense, we can give such advice: the more powerful the PC is planned, the larger the case ...

Full Tower: The dimensions of such a case: width 15-20cm, height 50-60cm. Such case has from 4 to 9 bays for 5.25" devices (example: DVD-ROM drive), has from 6 to 12 bays for 3.5" devices (example: HDD), has the ability to install seven expansion cards (for example, a TV tuner, a sound card). Also, such a case can accommodate a full-size ATX motherboard (we will talk about their sizes later). To put it simply, cases of this type are the largest, and the capacity of various hardware is huge. But here, of course, everything depends on the motherboard - how much it allows you to connect hard drives, expansion cards (which then find a place for themselves in the open space of the case), etc. Application: Basically, for powerful computers, focused exclusively on high performance, because. such system units contain a lot of fast components, which are known to generate a lot of heat, and in such a large case, cooling is not difficult.

Middle tower (Mid Tower): Perhaps the most common size among home desktop computers. Its dimensions: width 15-20cm, height 43-45cm. These cases can accommodate a full-sized ATX motherboard, a full-sized power supply, multiple hard drives, and quite a few hard drives. Application: It can be said - universal. The dimensions are acceptable for both high-performance PCs and regular medium PCs. home computer. The space inside the case allows airflow to circulate inside, usually without hindering the cooling of the case and devices. I recommend it for PC builds - if your PC size requirements are normal, and if you don't need a computer "on the shelf".

Mini Tower: Mainly distributed in the sector of office computers. Due to their small size (width 15-20cm, height 33-35cm) they allow you to install a few: (1-2 optical drives, 1-2 hard drives and about 4 expansion slots) and medium or lower performance devices. Firstly, because of the size, and secondly, because of the heating. There is not enough space in such a case - and therefore the requirements for the temperature of devices are higher, so as not to create nasty fan noise and overheating of devices. But in such a case you can fit components that are quite enough for office work with text, presentations and spreadsheets.

Mini PC (Small Form Factor): With their dimensions (width 20 cm, height 18-23 cm), they can accommodate a maximum of 2 expansion slots, few hard drives and imply a compact power supply. This implies that the user will mainly use the components built into the motherboard (which, by the way, is also small) such as integrated video and sound. By appearance these cases resemble household appliances. Their use is as office PCs or as the basis of a home theater. There is no question of cooling here, because. there are very few devices and they, according to their purpose, emit a little heat.

There are also form factors. Micro PC(which are even smaller compared to Mini PCs, but due to their size they have even more limitations) and desktop (horizontal cases that are on the table), but they are less common and it is unlikely that you will have to mess with them.

So, we looked at the form factors of cases. I hope you choose something suitable for you. If not, you can seek individual advice.

In the following articles from the form factor cycle, we will generally consider the form factors of the components of the system unit and other devices.

Final annual test for the 8th grade course with answers. It consists of block A, which includes 20 questions with a choice of one answer, block B, which consists of 5 questions. The main topics of the course according to the program of N.D. Ugrinovich are considered.

1 option

Block A.

A1. Information about the objects of the world around us is:

1. information
2. an object
3. item
4. Informatics

A2. Information presented in a language accessible to the recipient is called:

1. understandable
2. complete
3. useful
4. relevant

A3. A person receives the greatest amount of information with the help of:

1. hearing organs
2. organs of vision
3. olfactory organs
4. sense organs

A4. The binary code of each character when encoding textual information (in ASCII codes) occupies in the memory of a personal computer:

1. 1 byte
2. 2 bytes
3. 1 bit

A5. Temperature measurement is

1. storage process
2. transfer process
3. receiving process
4. protection process

A6. What is 1 byte?

1. 1024 KB
2. 4 bit
3. 8 bit
4. 10 MB

A7. The Morse code alphabet consists of:

1. zeros and ones
2. from dots and dashes
3. of 10 different signs
4. from one sign

A8. Assuming that each character is encoded by one byte, determine what is the information volume of the following statement by Jean-Jacques Rousseau:
Thousands of paths lead to error, to the truth - only one.

1. 92 bits
2. 220 bit
3. 456 bit
4. 512 bit

A9. Unicode encodes two bytes for each character. Determine the information volume of a word of twenty-four characters in this encoding.

1. 384 bits
2. 192 bits
3. 256 bit
4. 48 bit

A10. The meteorological station monitors air humidity. The result of one measurement is an integer from 0 to 100 percent, which is written using the smallest possible number of bits. The station made 80 measurements. Determine the information volume of the observation results.

1. 80 bit
2. 70 bytes
3. 80 bytes
4. 560 bytes

A11. Computer architecture is

1. technical description of computer device parts
2. description of devices for input-output of information
3. description software for computer operation
4. list of devices connected to the PC

A12. The device for inputting information from a sheet of paper is called:

1. plotter;
2. streamer;
3. driver;
4. scanner;

A13. Which PC device is designed to display information?

1. CPU
2. monitor
3. keyboard
4. record player

A14. Persistent storage is used to store:

1. especially valuable application programs
2. especially valuable documents
3. constantly used programs
4. programs for booting a computer and testing its nodes

A15. Driver is

1. long-term storage device
2. program that controls a specific external device
3. input device
4. output device

A16. Operating systems include:

1. database management systems
2. programming systems
3. application software
4. system software

A17. What is a computer virus?

1. application program
2. system program
3. programs that can "multiply" and covertly insert copies of themselves into files, disk boot sectors, and documents
4. database

A18. Majority antivirus programs detect viruses by

1. masking algorithms
2. samples of their code
3. habitat
4. destructive impact

A19. What makes it impossible to connect a computer to the global network:

1. computer type
2. composition of peripheral devices
3. no drive
4. no network card

A20. Mathematics textbook contains information of the following types:

1. graphic, text and audio
2. graphic, sound and numerical
3. purely numerical information
4. graphic, text and numerical

Block V.

Answer: 1d), 2a), 3c), 4b), 5e)

Answer: 1e), 2a), 3d), 4b), 5c)

AT 3. Which of the following applies to computer output devices? Write the letters in your answer.

1. Scanner
2. Printer
3. Plotter
4. Monitor
5. Microphone
6. speakers

Answer: b, c, d, e

Purpose		Device
1. Input device		a) monitor
2. Output devices		b) printer
		c) diskette
		d) scanner
		e) digitizer

Answer: 1d,d, 2a,b

AT 5. How many bits does the word "computer science" contain. Write only the number in your answer.

Option 2

Block A.

When completing the tasks of this part, out of the four options offered to you, choose one correct one.

A1. The subject of informatics is:

1. programming language
2. robot device
3. methods of accumulation, storage, processing, transmission of information
4. public awareness

A2. Information that reflects the true state of affairs is called

1. understandable
2. complete
3. useful
4. credible

A3. Information according to the method of its perception is divided into:

1. social, technological, genetic, biological
2. textual, numerical, graphic, musical, combined
3. visual, auditory, tactile, olfactory, gustatory
4. scientific, industrial, technical, managerial

A4. The binary code of each character when encoding textual information (in Unicode codes) occupies in the memory of a personal computer:

1. 1 byte
2. 2 bytes
3. 2 bits

A5. Blackmail using compromising materials is a process

1. information decoding
2. information encoding
3. information search
4. use of information (criminal)

A6. The minimum unit for measuring the amount of information is:

1. 1 baud
2. 1 bit
3. 256 bytes
4. 1 byte

A7. What number system does a computer use?

1. in binary
2. in hexadecimal
3. in decimal
4. all answers are correct

A8. Assuming that each character is encoded by one byte, determine what is the information volume of the following statement by Alexei Tolstoy: The one who does nothing is not mistaken, although this is his main mistake.

1. 512 bit
2. 608 bit
3. 8 KB
4. 123 bytes

A9. Assuming that each character is encoded with 16 bits, estimate the information volume of the following Pushkin phrase in Unicode encoding: A habit from above is given to us: It is a substitute for happiness.

1. 44 bits
2. 704 bits
3. 44 bytes
4. 704 bytes

A10. 678 athletes participate in cyclocross. A special device registers the passage of each of the participants of the intermediate finish, recording its number using the minimum possible number of bits, the same for each athlete. What is the information volume of the message recorded by the device after 200 cyclists have passed the intermediate finish line?

1. 200 bit
2. 200 bytes
3. 220 bytes
4. 250 bytes

A11. Corps personal computers there are:

1. horizontal and vertical
2. internal and external

A12. Scanners are:

1. horizontal and vertical
2. internal and external
3. manual, roller and flatbed
4. matrix, inkjet and laser

A13. Printers cannot be:

1. tablet;
2. matrix;
3. laser;
4. jet;

A14. You can save information before turning off your computer

1. in RAM
2. in external memory
3. in the disk controller
4. in ROM

A15. The program is:

1. algorithm written in a programming language
2. instruction set operating system computer
3. directed graph indicating the order in which computer commands are executed
4. protocol for the interaction of computer network components

A16. Operating system:

1. software system that provides joint work all computer devices for processing information
2. system of mathematical operations for solving individual problems
3. scheduled maintenance system and Maintenance computer technology
4. document scanning software

A17. What files infect macro viruses?

1. executive;
2. graphic and sound;
3. files Word documents and Excel spreadsheets;
4. html documents.

A18. What is the action of the antivirus program based on?

1. waiting for a virus attack
2. to compare program codes with known viruses
3. deleting infected files
4. on creating viruses

A19. A device that converts analog signals to digital and vice versa is called:

1. LAN card
2. modem
3. CPU
4. adapter

A20. Among the main advantages of working with text in text editor(in comparison with a typewriter) should be called:

1. the ability to edit text multiple times
2. the possibility of faster typing
3. the ability to reduce the complexity when working with text
4. the ability to use different fonts when typing

Block V.

B1. Establish a correspondence between the types of process information and the actions that implement them.

1) LETTER		a) HPSNB
2) SHAPE		c) VFLGB
3) SHINE		b) CHYHSB
4) NUMBER		d) GPSS
5) RAVEN		e) VMETL

Answer: 1d, 2b, 3a, 4c, 5d

AT 3. Which of the following applies to computer input devices? Write the letters in your answer.

1. Scanner
2. Printer
3. Plotter
4. Monitor
5. Microphone
6. speakers

Answer: b, d

AT 4. When determining the correspondence for all elements of the 1st column, indicated by a number, one element of the 2nd column, indicated by a letter, is indicated. In this case, one element of the 2nd column may correspond to several elements of the 1st column (for tasks of multiple matching) or not correspond to any of the elements of the 1st column (for tasks of one-to-one correspondence).

Answer: 1d,d 2a,b

AT 5. How many bytes contains the word "information". Write only the number in your answer.

3 option

Block A.

When completing the tasks of this part, out of the four options offered to you, choose one correct one.

A1. One of the fundamental concepts of computer science is:

1. Pascal
2. information
3. link
4. Norton Commander

A2. Information that does not depend on personal opinion or judgment is called:

1. credible
2. relevant
3. objective
4. complete

A3. Visual information carries:

1. painting
2. thunder sound
3. apple taste
4. mosquito bite

A4. In what language is the information processed by the computer?

1. in BASIC
2. in text form
3. in binary codes
4. in decimal number system

A5. Translation of the text from English into Russian can be called:

1. storage process
2. receiving process
3. protection process
4. processing process

A6. Arrange the signs<, =, >in the following chain: 20 bytes... 1000 bits... 1 MB... 1024 KB... 1 GB

1. <, <, =, <
2. >, =, >, <
3. <, >, =, <
4. =, >, =, <

A7. The code is called:

1. character sequence
2. a set of symbols (symbols) for representing information

A8. Assuming that each character is encoded by one byte, determine what is the information volume of the following statement by Rene Descartes:
I think, therefore I am.

1. 28 bit
2. 272 bits
3. 32 KB
4. 34 bits

A9. Assuming that each character is encoded with 16 bits, estimate the information volume of the following phrase in Unicode encoding:
There are 6000 milliliters in six liters.

1. 1024 bytes
2. 1024 bits
3. 512 bytes
4. 512 bit

A10. The production has an automated system for informing the warehouse about the need to deliver certain groups of consumables to the workshop. The system is designed in such a way that a conditional number of consumables is transmitted to the warehouse via a communication channel (in this case, the same, but the minimum possible number of bits in the binary representation of this number is used). It is known that a request was sent for the supply of 9 groups of materials out of 19 used in production. Determine the size of the sent message.

1. 35 bytes
2. 45 bit
3. 55 bit
4. 65 bytes

A11. In which PC device is information processed?

1. external memory
2. display
3. CPU

A12. Information input device - joystick - is used:

1. for computer games;
2. when carrying out engineering calculations;
3. to transfer graphic information to a computer;
4. to transfer character information to a computer;

A13. There are no monitors

1. monochrome
2. liquid crystal
3. based on CRT
4. infrared

A14. External memory includes:

1. modem, disk, cassette
2. cassette, optical disc, tape recorder
3. disc, cassette, optical disc
4. Mouse, light pen, hard drive

A15. Application software is:

1. help application for programs
2. text and graphics editors, training and testing programs, games
3. set of game programs

A16. OS:

1. DOS, Windows, Unix
2. Word, Excel, PowerPoint
3. (composition of the hospital department): head. department, 2 surgeons, 4 medical sisters
4. dr. Web, Kaspersky Anti-Virus

A17. Viruses that can live in document files are called:

1. network
2. macro viruses
3. file
4. bootable

A18. Which of the following programs are antivirus programs?

1. Doctor Web, AVG
2. WinZip, WinRar
3. Word, PowerPoint
4. Excel, Internet Explorer

A19. The combination of computers and local networks located at a remote distance, for the general use of world information resources, is called ...

1. the local network
2. global network
3. corporate network
4. regional network

A20. When working with a text editor, the following personal computer hardware is required:

1. keyboard, display, processor, RAM
2. external storage device, printer
3. mouse, scanner, hard drive
4. modem, plotter

Block V.

B1. Establish a correspondence between the types of process information and the actions that implement them.

Answer: 1a, 2d, 3c, 4b, 5d

1) MAST		a) LPShLB
2) HAIR		c) NBSSHUB
3) CAT		b) PUGEOU
4) BOUQUET		d) WFLOW
5) ANSWER		e) GMPMT

Answer: 1c, 2d, 3a, 4d, 5b

AT 3. Which of the following applies to media? Write the letters in your answer.

1. Scanner
2. flash card
3. Plotter
4. HDD
5. Microphone

Answer: b, d

AT 4. When determining the correspondence for all elements of the 1st column, indicated by a number, one element of the 2nd column, indicated by a letter, is indicated. In this case, one element of the 2nd column may correspond to several elements of the 1st column (for tasks of multiple matching) or not correspond to any of the elements of the 1st column (for tasks of one-to-one correspondence).

Answer: 1d,e 2a,b,c,e

AT 5. How many bytes contains the word "message". Write only the number in your answer.

4 option

Block A.

When completing the tasks of this part, out of the four options offered to you, choose one correct one.

A1. Search, collection, storage, transformation, use of information is the subject of study:

1. informatics
2. cybernetics
3. robotics
4. Internet

A2. Information that is significant and important at the moment is called:

1. complete
2. useful
3. relevant
4. credible

A3. A person receives tactile information through:

1. special devices
2. thermometers
3. barometers
4. sense organs

A4. The code is called:

1. a rule describing the mapping of a set of characters from one alphabet to a set of characters from another alphabet
2. arbitrary finite character sequence
3. a rule describing the mapping from one set of characters to another set of characters or words
4. fixed length binary word
5. sequence of words over binary character set

A5. Video recording of the school holiday is carried out for

1. information processing
2. information storage
3. transmission of information
4. information search

A6. What is 5 kilobytes?

1. 5000 bytes
2. 5000bit
3. 5120 bit
4. 5120 bytes

A7. What do computers mean by zero or one when writing a binary code?

1. Yes or no
2. 0 or 1
3. no electrical signal or there is an electrical signal
4. all answers are correct

A8. Assuming that each character is encoded by one byte, estimate the information volume of the following sentence from Pushkin's quatrain:
Singer-David was small in stature, But he knocked down Goliath!

1. 400 bit
2. 50 bit
3. 400 bytes
4. 5 bytes

A9. Assuming that each character is encoded with 16 bits, estimate the information volume of the following sentence:
Blessed is he who believes, he is warm in the world!

1. 78 bit
2. 80 bytes
3. 312 bit
4. 624 bits

A10. The chessboard consists of 8 columns and 8 rows. What is the minimum number of bits required to encode the coordinates of one chess field?

A11. The minimum composition of a personal computer ...

1. hard drive, floppy drive, monitor, keyboard
2. monitor, keyboard, system unit
3. printer, keyboard, monitor, memory
4. system unit, modem, hard drive

A12. Which of the following input devices belongs to the class of manipulators:

1. touchpad;
2. joystick;
3. microphone;
4. keyboard

A13. Printers are:

1. desktop, portable
2. matrix, laser, inkjet
3. monochrome, color, black and white
4. based on CRT

A14. To store the programs required to start and test the computer when it is turned on, you must:

1. CPU

A15. A graphic editor is a program designed to ... create

1. graphic image of the text
2. editing the type and style of the font
3. work with graphics
4. charting
5. there are no correct answers

A16. On the Windows operating system, a native file name cannot contain the character

1. question mark (?)
2. comma (,)
3. dot (.)
4. addition sign (+)

A17. On what basis was the name "virus" attributed to computer programs?

1. ability to mutate
2. ability to self-reproduce
3. ability to divide
4. resizing ability

A18. Antivirus programs are

1. scanning and recognition programs
2. programs that detect and treat computer viruses
3. programs that only detect viruses
4. archiving programs, unarchiving programs

A19. Global network

1. association of computers within the same city, region, country
2. combining computers located at a great distance from each other
3. association of local networks within the same corporation to solve common problems
4. combining computers located at a short distance from each other

A20. Text editing is:

1. the process of making changes to existing text
2. the procedure for saving text to disk as a text file
3. the process of transmitting textual information over a computer network
4. the procedure for reading previously created text from an external storage device

Block V.

B1. Establish a correspondence between the types of process information and the actions that implement them.

Answer: 1b, 2d, 3a, 4c, 5d

AT 2. Encode the words with the Caesar code.

1) RUMBLING		a) SCHBRLB
2) HAT		c) VPLBM
3) GLASS		b) LMBTT
4TH GRADE		d) SPLPU
5) POST		e) TUPMV

Answer: 1d, 2a, 3c, 4b, 5d

AT 3. Which of the following applies to internal memory? Write the letters in your answer.

1. HDD
2. diskette
3. magnetic disk

Answer: b, c

AT 4. Set match

Net		Description
1. Local network		a) combining computers located at a great distance from each other
2. Regional network		b) combining local networks within one corporation to solve common problems
3. Corporate network		c) association of computers within the same city, region, country
4. Global network		d) combining computers located at a short distance from each other

Answer: 1d, 2c, 3b, 4a

AT 5. How many bytes contains the word "communication". Write only the number in your answer.

The operating system, installed programs, documents, photos, music and movies are stored on the hard drive. The size of the HDD (hard disk) is measured in gigabytes. It is believed that the more the better. As they say, there is never too much free space.

The front panel of the PC system unit, as a rule, contains two buttons:

• Power - used to turn on the computer;
• Reset - used when an emergency restart of the computer is required if it is frozen.

Also on the front panel you can find the following elements:

• indicators - LEDs and lights that display PC operation: indication of computer operation, indication of the status of the hard drive.
• disk drives and optical drives are devices designed to work with such storage media as floppy disks and optical disks.
• connectors - designed to connect some external devices. Most often, these are USB connectors, as well as a headphone and microphone jack.

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A bit of history The first cases for personal computers of the XT generation (8086, 8088) were the standard of strength and had the desktop form factor. Having handed over such cases for scrap, it was possible to get a good deal for them, but they also cost a lot at that time, since a personal computer was literally a luxury and not “consumer goods”. A computer in such a case stood on a table, and a CRT monitor was installed on top of it, which also had a solid weight, which means that manufacturers did not save on metal and did everything for ages. The insides had many partitions and ties, it was difficult to break something in such a case without a special tool. Many cases were locked with a key in order to avoid unauthorized access to the insides of the PC. The picture was only spoiled by the literally gray and uncomplicated design, because the PC had to solve serious problems, and not please the eyes with a lot of LEDs.

The case is an important element that ensures the placement and rigid fixation of all its devices, providing them with power and protecting the rather fragile "insides" from the environment. There are several housing standards - AT, ATX, micro ATX. The ATX standard case is more modern, most new motherboards are designed specifically for it. It is characterized by easier access to the internal components of the computer (often without the use of a screwdriver), improved ventilation inside the case, the ability to install more full-size expansion cards, advanced power management options. The benefits provided by ATX - software shutdown, power on by signals from various internal devices, etc. The Micro ATX case is a small-sized option, well suited for compact base PCs with a minimum of expansion cards (minimum dimensions and affordable price). The most widely used cases are of two types: Desktop, located horizontally on the desktop and used for the most part in PC models manufactured by firms - "brands" and Tower, vertically located and more massive type of case. Cases of the latter type are subdivided, in turn, into micro -, mini -, midi - and big - tower, differing in the number of bays for 5.25 "drives: respectively, micro - tower have 1 seat for such drives, mini - tower - 2, midi - tower - 3 and big - tower - 4 or more.

Desktop Most often in a case of this type are placed horizontally from 2 to 3 devices of the 5.25 "format and vertically 2 - of the 3.5" format, and one of them is with external access. Such cases take up quite a lot of space in the workplace, they cannot always provide convenient access to internal devices, and sometimes there are problems with normal processor cooling. All this indicates that the time of desktop-type cases is inexorably passing, and after all, the first PCs appeared in such cases, no one had heard of the tower at that time. But now desktops have absolutely no advantage over towers. Even well-known brands, which not so long ago produced their models only in such cases, are more and more inclined towards more practical towers.

Slim The development of the idea of ​​miniaturization in relation to the computer field has given rise to such a miracle as the extremely integrated motherboards of the Flex-ATX format and their natural continuation - either Slim or Super Slim cases. In general, all cases are cramped, extremely uncomfortable, there are a minimum of opportunities, and the possibilities for upgrading are very limited, but on the other hand, outwardly they look original and exclusive, but only such babies cost much more than full-featured machines, and are advertised by manufacturers as inexpensive solutions for offices and sometimes for home use.

Mini-tower A rather small mini-tower case used to be the most widespread, but now it is much less common, since problems can arise with the placement of full-size ATX motherboards in it, only small-sized boards of micro-TX and flex-formats remain. ATH. Such cases are most often used in PCs of the simplest configurations and are used as office machines or network terminals.

Midi (middle) - tower The most common case format today - midi (middle) - tower ATX, provides the use of a large number of drives and almost all types of motherboards with acceptable overall dimensions. Being a real "workhorse", optimally adapted to solve the widest range of tasks, cases of this type are used almost everywhere.

Big (full) - tower Being the largest, big - tower cases can accommodate motherboards of any size and the largest number of 5.25" devices most often. In addition, they are usually equipped with high-power power supplies. The main area of ​​​​application of cases is - workstations, small servers and computers for advanced users.However, due to the increasing expansion of inexpensive IDE RAID controllers into mainstream devices, the need for a large amount of disk storage space can make big - tower cases the most common devices, especially if take into account that modern high-speed hard drives heat up noticeably during operation, and devices mounted in 5-inch bays and designed to cool 3-inch HDDs have already begun to appear.

Barebone This is a simplified manufacturer's solution that includes everything to quickly build a computer and needs only such variable components as a processor, memory and hard drive. The installation process of the latter takes a matter of minutes, and the computer is ready. As a rule, in such systems, manufacturers use their own components, so replacing the motherboard or adding a component can cause some difficulties. However, usually, such systems are used as mass corporate computers, or as a personal computer for a person who is not burdened with the needs for an upgrade.

Server Enclosures. This group of cases includes a huge number of different solutions, for the most part very specific. Server cases can be designed for mounting them in racks, have a large number of fans and places for their installation, some are equipped with thermal control systems and the ability to install multiple power supplies. There is another class of server cases: large Tower, designed for conventional installation (not in racks), with a large number of compartments for installing devices, several power supplies. Both categories of enclosures typically have hot-swappable components. Rackmount enclosures have standardized dimensions. Their thickness can vary from 1 Units (U) to three (1U 3U), "non-integer" values ​​are also acceptable (2.5U, for example). The thinnest 1U are usually designed for the installation of special components with increased compactness. Among them are low-profile heatsinks, motherboards that have slanted memory sockets and are designed to install expansion cards parallel to the surface of the board.