CPU
The processor is the central unit of the computer, where information is processed.
It controls the operation of all devices and performs all logical and arithmetic operations.
The main unit of the processor is arithmetic unit
(ALU - arithmetic logic unit). It performs all operations on the data. The processor includes control device
, which controls all devices and monitors the sequence of command execution.
Currently, the processor is implemented in hardware in the form of LSI (large-scale integrated circuits). Modern PENTIUM processors contain millions of functional elements. The processor can process numerical, textual, graphic, video and sound information.
The processor works in close contact with a microcircuit called a clock generator (GTC). The GTS generates periodic pulses that synchronize the operation of all computer nodes. This is a kind of metronome inside the computer. The processor works to the rhythm of this metronome. The clock frequency is equal to the number of cycles per second. The cycle is the time interval between the start of the current pulse and the start of the next one. A certain number of clock cycles is allocated for each operation to be performed by the processor. It is clear that if the "metronome" beats faster, then the processor works faster. The clock frequency is measured in megahertz - MHz. A frequency of 1 MHz corresponds to a million cycles per second. Here are some characteristic clock frequencies of microprocessors: 130 MHz, 266 MHz, 1000 MHz, 2000 MHz, 3 GHz, etc.
computer memory
All information entered enters the storage device or machine memory, where it is stored until the moment when it is needed.
The carrier of information is the physical environment in which it is recorded.
Paper, photographic film, brain cells, punched cards, punched tapes, magnetic tapes and disks or computer memory cells can act as a carrier. Modern technology offers more and more new types of information carriers. To encode information, they use the electrical, magnetic and optical properties of materials. Carriers are being developed in which information is recorded even at the level of individual molecules.
Computer memory can be internal or external. Inner memory includes permanent and operational.
Persistent memory
(ROM - Read Only Memory). A feature of the ROM is that information can only be read from it during operation, but it cannot be written. A characteristic feature of the ROM is the preservation of information when the computer's power is turned off. The information recorded in the ROM is entered once (usually at the factory) and is stored permanently (when the computer is turned on and off) throughout the entire period of PC operation and cannot be changed during operation. ROM is fast, non-volatile memory. The ROM stores information, the presence of which is constantly needed in the computer. These are usually components. operating system(hardware control programs, computer initial boot program, etc.)
In modern PCs, there is another type of fast memory that has a special purpose. This is video memory. Video memory stores the code of the image displayed on the display.
RAM
(OP) is a computer device designed to store data (source, intermediate and final) and programs (a set of instructions). Everything you enter into a computer is stored in RAM (Random Access Memory). The English name for RAM is Random Access Memory (RAM), which translates as "random access memory". This name emphasizes the fact that the processor can access memory cells in any order, while the time to read / write information for all cells is the same (it is measured in microseconds).
Information stored in RAM can be changed. When you turn off your PC, all information in RAM is erased. This memory is called operational, because. it allows you to record and transmit information at a very high speed. However, the amount of RAM is limited, so there is a need to connect external memory. Physically, OP is made in the form of LSI with different information capacity.
To speed up data access, a special device called a cache is used. Cache
- this is a "super-operational" memory of a relatively small volume (usually up to 520,000 characters), built on a different element base than RAM. The cache stores the most frequently used areas of RAM. When the processor accesses memory, it first searches for the necessary data in the cache. Since the access time to cache memory is several times less than to RAM, the average memory access time decreases.
External memory
as if it replaces books with programs and algorithms described in them. External memory devices or VZU (external storage devices) include:
Floppy disk drives
Hard Disk Drives
Laser CD drives
Magneto-optical systems
streamers
Flash drives
The main purpose of external memory is long-term storage of a large amount of information. For the user, some technical and economic indicators of external storage devices and information carriers are essential: information capacity, information exchange rate, reliability of its storage and cost.
Magnetic media
The first computers used ordinary tape recorders as external memory. Today, tape recorders are used only for Reserve copy contents of hard magnetic disks (MD), tk. on disks, information can be lost “thanks to” computer “viruses”. An assistive tape recorder that records information from a computer onto a special magnetic tape cassette (ML) is called streamer.
The streamer cassette has a very large capacity and allows you to store information from all over the world. hard drive.
The basis for recording, storing and reading information on magnetic media is the magnetic principle: during the recording process, the media moves relative to the head with a core of magnetically soft material, electrical impulses create a magnetic field in the head, which sequentially magnetizes or does not magnetize the elements of the media.
When reading information, the magnetized sections of the carrier cause a current pulse in the head, which makes it possible to qualitatively recognize information. The method of recording and reading information on ML and MD is similar to the operation of a conventional tape recorder.
HDD
is a plate of non-magnetic material, on the surface of which a magnetic layer is deposited. Its average uptime is hundreds of thousands of hours. Hard magnetic disks consist of several disks placed on the same axis and rotating at a high angular velocity (several thousand revolutions per second), enclosed in a metal case. The read/write heads move across all disk surfaces at once.
A hard magnetic disk (HMD), or hard drive, is designed for permanent storage of information used when working with a computer: operating system programs, frequently used software packages, text editors, etc. Modern hard disk drives have a rotation speed of 3600 to 7200 rpm . This may be a glass disc (with a metallic surface film, such as cobalt), not sensitive to temperature. Information capacity - up to 48 billion characters.
A relatively new concept: a flash drive. This is a device for long-term data storage, with the possibility of multiple rewriting, implemented on memory chips (that is, just like RAM). Advantages: low power, reliability in operation, small size, shock resistance, absence of mechanical and moving parts, memory capacity from 2 to 200 MB and even up to 1.7 GB. The disadvantage is the high price of the device. Despite the high cost, it seems that flash drives will eventually replace hard drives.
Floppy disks are used for the exchange of programs between computers and for the delivery of software products. Flexible MD (GMD) are designed to transfer documents and programs from one computer to another, store archival copies and information that is not constantly used on a computer.
Floppy disks are placed in a thick paper envelope or in a plastic case. There is a hole in the center of the disc to allow the disc to rotate in the drive. The protective envelope has an elongated hole through which information is written / read. On the side edge of the floppy disks there is a small cutout that allows recording, but if the cutout is sealed, recording becomes impossible (the disk is protected). On some floppy disks, write protection is provided by a safety latch in the lower left corner of the plastic case.
Flexible MD with a diameter of 5.25 inches were used until the mid-80s of the 20th century and could store up to 1.5 million characters of information. 5.25-inch floppy disks did not provide good physical protection for the media. Currently, 3.5-inch GMDs are still in use, which have a capacity of 1.8 million characters. Protection of the magnetic layer is especially relevant, so the disk itself is hidden in a durable plastic case, and the contact area of the heads with its surface is closed from accidental touches by a special shutter, which automatically moves away only inside the disk drive.
Any magnetic disk is not initially ready for operation. To bring it into working condition, it must be formatted, that is, the disk structure must be created. Information on the GMD is stored on magnetic concentric tracks, divided into sectors, marked with magnetic marks, and the GMD also has cylinders - a set of tracks located one above the other on all working surfaces of the disks. All the tracks of the magnetic disks on the outer cylinders are larger than those on the inner ones. Therefore, with the same number of sectors on each of them, the recording density on the inner tracks should be greater than on the outer ones. The number of sectors, sector capacity, and, consequently, the information capacity of the disk depend on the type of drive and formatting mode, as well as on the quality of the disks themselves.
The disadvantages of magnetic media are the ability to destroy the magnetic layer with frequent reading of information and from the effects of magnetic fields and the phenomenon of "chewing" the tape. The advantage is the ability to record information many times.
Optical media
There are optical disc drives (CD-ROM), where information is recorded by a laser. Outwardly, they are no different from audio CDs. CD-ROM disks (Compact Disk Read Only Memory) have a capacity of up to 3 billion characters of information, high reliability of information storage, and durability (the predicted service life of its high-quality performance is up to 30-50 years).
This is interesting!The CD-ROM manufacturing process consists of several steps. First, information is prepared for the master disk (the first sample), it and the replication matrix are made. Encoded information is applied to the master disk by a laser beam, which creates microscopic depressions on its surface, separated by flat areas. Digital information is represented by an alternation of depressions (non-reflective spots) and light-reflecting islands. Copies of the negative of the master disc (matrix) are used to press the CDs themselves. The replicated CD consists of reflective and protective layers. Finely dusted aluminum is usually used as a reflective surface. Unlike magnetic disks, which have concentric circle tracks, a CD-ROM has only one physical track in the form of a spiral running from the outer edge of the disc to the inner (like on a phonograph record).
CD-ROM drives use the optical principle of reading information. The laser beam falls on the surface of a rotating CD-ROM disk and the beam is reflected in it with an intensity corresponding to the values 0 and 1. The laser beam hits the light reflecting island, is deflected by the photodetector, which interprets it as a binary unit. The laser beam falling into the cavity is scattered and absorbed - the photodetector fixes a binary zero.
To load a CD into the drive, either one of the varieties of the sliding panel or a special transparent cassette is used. They produce devices that allow you to independently record special CDs. Unlike conventional discs, these discs have a reflective layer of gold. These are the so-called rewritable CD-Rs. Such discs usually serve as master discs for further replication or archiving.
Capacitance increase reserve - increasing the recording density by reducing the laser wavelength. This is how CDs appeared, capable of storing almost 5 billion characters of information on one side and 10 billion characters on two sides. It is also planned to create a two-layer recording scheme, i.e. when on one side of the media there are two surfaces spaced in depth with recorded data. In this case, the information capacity of the CD increases to 9 billion characters on one side.
The disadvantage of a CD-ROM disc is that information is written to the media only once. The advantage of a CD-ROM disc is the endless reading of information without loss.
It seems that CD-ROMs, which have become familiar, will soon become a thing of the past. Rewritable CDs (CD-RW, CD-ReWritablie) are already widely used. CD-RW discs removed the fundamental limitation of CD-ROM, associated with the possibility of only one-time recording of information. Recording on a CD-R disc is possible only once and is done by the user using a compact and inexpensive recording drive.
Digital laser DVDs appeared. Their main difference is a higher recording density. Thus, the dominant computer market is a disk with a diameter of 120 mm and a capacity of up to 5 billion characters. It is believed that the capacity of DVDs can reach 15 billion characters.
A distinction is made between DVD-ROM and DVD-RAM discs. DVD-ROM is read-only. DVD-RAM for reading and writing. To read DVDs, you need a special drive that also reads CD-ROMs.
One of the achievements of the 20th century is magneto-optical disks. They use the advantages of magnetic and optical media: multiple recording and multiple reading. Magneto-optical disks may prove to be one of the most viable devices for data storage. The fact is that CD-ROMs are convenient for storing information, and in working with it they turn out to be slower than hard magnetic disks. Therefore, information from CDs is usually copied onto an MD, with which they work. Such a system is not suitable if the work is related to databases, which, due to the large information capacity, are just more profitable to place on CD-ROM. In addition, CDs used in currently in practice, are not writable. Magneto-optical disks are devoid of these shortcomings. It combines the achievements of magnetic and optical technologies. They can write information and quickly read it. They retain all the advantages of the GMD (portability, the possibility of separate storage, increase in computer memory) with a huge information capacity.
In magneto-optical systems, magnetic recording is made on the surface of a compact disc, which is preliminarily strongly heated by a laser beam. The first magneto-optical disks looked like a 3.5-inch floppy disk. Then 5.25-inch disks were created, which also fit in a plastic case. After that, magneto-optical disks appeared without a case, i.e. exactly the same as conventional laser audio discs and these achievements have been mentioned above.
Information input-output devices
Information input-output devices organize a dialogue between the user and the computer.
In order for a computer to perform useful information processing functions, it must first be introduced. The keyboard is the most famous and widespread input device for information in a computer. At the physical level, it is a set of mechanical sensors that perceive pressure on the keys and close in one way or another a certain electrical circuit. The graphical manipulator - "mouse" also belongs to the information input devices in the computer. It allows you to control the state of objects displayed on the screen: menus, light buttons, etc. A variation of the graphical “mouse” manipulator is the “trackball”, here the movement of the manipulator is carried out using a large ball inside. It does not require a rug, does not take up much space on the table, the ball is rotated by hand.
There are a large number of other mouse designs, such as:
1. Wireless
mouse - signals from the mouse are transmitted using a radio transmitter.
2. Optical
mouse - uses a special mat and a beam of light instead of a ball.
3. Foot
mouse.
Joystick
(used in game consoles) enters the coordinate-numeric information necessary for the implementation of games with the help of fingers; graphics tablet (digitizer)
provides data entry (coordinates of points and curves) with high accuracy; device "light pen"
, which captures and moves a point or cursor on the display screen, also allows information to be entered into the computer; scanner
- an input device that scans any drawing line by line and transfers information about it to a personal computer (used in publishing houses, in well-equipped photo labs).
The principle of operation of the scanner is as follows: the scanned image is illuminated with white light. Reflected light through a reducing lens falls on a photosensitive semiconductor element. Each scan line corresponds to certain voltage values on it, then the voltage values \u200b\u200bare converted into digital form. Scanners are handheld, flatbed and drum. Manual ones are almost non-existent. Drum scanners provide the highest quality. Distinguish between black and white and color scanners. The scanner enters the image as a set of points, specifying a color number for each coordinate. According to these data, a copy of the image is entered into the memory. If you enter text using a scanner, you need special programs.
In the early days of computer technology, there were devices for input-output of information from punched cards and punched tapes
. People of the old school remember well rolls of punched tapes and decks of punched cards, which were chopped into noodles for a few seconds by a faulty reader. They had serious shortcomings: the paper was quickly torn, and it was difficult to correct mistakes.
Printing devices
, reminiscent of ordinary typewriters, were previously also used for input / output of information. But due to the strong noise during operation of these devices, users abandoned them.
Display
is a device for input-output of textual and graphic information, as it includes monitor
And keyboard
. Three types of monitors are in use: flat-screen liquid crystal monitors, gas-plasma monitors, and cathode-ray tube monitors. Monitors are available in color and monochrome.
Printers
print documents and programs on paper (there are several types of printers: matrix
where printing is done with thin metal rods striking the paper through an ink ribbon; jet
where printing is carried out by microdrops of special ink blown onto paper using nozzles; laser
printers that provide the highest quality prints use the principle of xerography: the image is transferred to paper from a special drum, to which dye particles are electrically attracted). Other devices for outputting information to paper - plotters
print drawings and graphs on paper. The speakers are designed for acoustic output (playback) of sound information, both already stored in the PC memory in the form of files, and coming to the PC from external music devices. All these devices are called peripheral.
To enter information into computers, digital video cameras
And cameras
, speech input and output are increasingly used. It is hard to imagine what will become common tomorrow. Portable computers without keyboards have appeared that can recognize and enter handwritten text. The image can be displayed on data helmet
- two miniature screens in front of the eyes create a stereo image. info gloves
can transmit images of human fingers to a computer and, receiving information from a computer, resist human movements. infosuits
are able to perceive the position of the human body and imitate the touch or pressure on the human skin by computer commands. All these information devices
allow the creation of so-called artificial realities
(virtual world), where a person operates in an imaginary world created by a computer, receiving through his senses the corresponding complexes of sensations.
For successful "communication" with a computer, it is harmful to perceive it as a black box that is about to give out something unexpected. To understand the computer's reaction to your actions, you need to know how it works and how it works.
In thatIn the IT lesson, we will learn how most computing devices work (which include not only personal computers).
What processes all the information in a computer
The main task of a computer is process information, that is, to perform calculations. Most of the calculations are performed by a special device -. This is a complex microcircuit containing hundreds of millions of elements (transistors).
What the program tells the processor to do at a given time, it indicates what data needs to be processed and what needs to be done with it.
Programs and data are loaded from the storage (hard disk).
But HDD – relatively slow device, and if the processor waited until the information was read, and then written back after processing, then it would remain idle for a long time.
Let's not leave the processor idle
Therefore, a faster storage device (Random Access Memory, RAM) was installed between the processor and the hard disk. This is a small printed circuit board that contains fast memory chips.
IN RAM all necessary programs and data are read from the hard disk in advance. During work cpu accesses RAM, reads the commands of the program, which tells what data to take and how to process it.
When the computer is turned off, the contents of RAM are not stored in it (unlike the hard drive).
Process of information processing
So, now we know which devices are involved in information processing. Let's look now at the whole process of calculations.
When the computer is turned off, all programs and data are stored on the hard disk. When you turn on your computer and program start, the following happens:
Information input and output
In order for the computer to receive information for processing, it must be entered. For this, they are used input devices:
- Keyboard(with the help of it we enter text and control the computer);
- Mouse(using the mouse we control the computer);
- Scanner(we enter the image into the computer);
- Microphone(recording sound), etc.
To display the result of information processing, we use output devices:
- Monitor(display the image on the screen);
- Printer(output text and image on paper);
- Acustic systems or "speakers" (listen to sounds and music);
In addition, we can input and output data to other devices using:
- External drives(from them we copy the already existing data to the computer):
- flash drive,
- compact disc (CD or DVD),
- Portable Hard Drive,
- diskette;
- computer network(we receive data from other computers via Internet or city network).
If we add input-output devices to our scheme, we get the following diagram:
That is the computer works with zeros and ones, and when information arrives at the output device, it translated into familiar images(image, sound).
Summing up
So, today, together with the site, we learned how does a computer work. In short, the computer receives data from input devices (keyboard, mouse, etc.), puts it on the hard disk, then transfers it to RAM and processes it using the processor. The processing result is returned first to RAM, then either to the hard disk, or immediately to the output device (for example, a monitor).
If you have any questions, you can ask them in the comments to this article.
You can learn more about all the devices listed in today's lesson from subsequent lessons on the IT-lessons website. In order not to miss new lessons, subscribe to the news of the site.
Copying prohibited
Let me remind you that the IT-lessons website has constantly updated reference books:
Video supplement
Today is a small informative video about the production of processors.
P.S. In the next lesson - Computer external device, description of external connectors, indicators and buttons. Do not miss!
A. Keyboard
c.display
d. processor
107. Video memory is ...
A. electronic memory for long-term storage of programs and data
B. memory for storing computer configuration settings
C. memory used to store the image displayed on the monitor screen
D. electronic memory for storing programs and data that are being processed by the processor at a given time
108. Modem is a device...
A. for printing information
B. to process information at a given time
C. information storage
D. to transmit information over a telephone channel
109. Monitor is…
A. device for long-term storage of large amounts of data and programs
B. a device for entering alphanumeric data, as well as control commands
D. device for manipulator type
110. Floppy disks (floppies) are designed for ...
A. long-term storage of information, the volume of which exceeds 10 MB
B. displaying text and graphic information
C. transferring documents and programs from one computer to another, storing information that is not constantly used on a computer
D. recording information on magnetic tape cassettes
111. A hard drive is...
A. a device for storing large amounts of data and programs used when running a PC
B. a device for recording data and programs on magnetic tape cassettes
C. device for displaying text and graphic information
D. a device for controlling the operation of a personal computer according to a given program
112. A printer is a device for ...
A. transferring information from one computer to another
B. input graphic information
C. putting information on paper
D. Long-term storage of data and programs
113. CD-ROM is…
A. a device used only for writing information to a CD
B. a device for recording information on magnetic tape cassettes
C. a device for displaying information on a sheet of paper
D. a device used to read information from a CD and transfer it to a computer
114. The concept of computer science:
A. information processes occurring in complex systems
B. ways to perform arithmetic operations on a computer
C. Computing equipment such as calculator, manipulator, computer and computing
D. the branch of science and technology that investigates the issues of information processing using
modern technical means
E. answers a) and c)
115. Folder is...
A. program my computer
B. program explorer
C. is the name of a group of files combined according to some attribute
D. bulk file
E. collection of files and documents
116. What is a directory (directory or folder)?
A. this is the name of a group of files combined according to some attribute
B. this is the same as the disk drive
C. It is a storage device
D. It is a data processing software tool
E. this is a software and hardware system designed to generate information about
programs
117. Windows is:
A. application program
b. utility
C. driver
D. operating system
118. The line on which the start button is located is called:
a. toolbar
B. desktop
C. taskbar
d. label
E. answers a) and c)
119. What type of program are presentation preparation?
A. system software
B. Applied by
C. instrumental environments
d. operating system
E. Utilities
120. Spreadsheet is:
A. a set of numbered rows and columns named using letters of the Latin alphabet
B. set of named rows and numbered columns using Latin letters
C. collection of numbered rows and columns
D. a collection of rows and columns arbitrarily named by the user
A. Keyboard
B. external memory
c.display
d. processor
107. Video memory is ...
A. electronic memory for long-term storage of programs and data
B. memory for storing computer configuration settings
C. memory used to store the image displayed on the monitor screen
D. electronic memory for storing programs and data that are being processed by the processor at a given time
108. Modem is a device...
A. for printing information
B. to process information at a given time
C. information storage
D. to transmit information over a telephone channel
109. Monitor is…
A. device for long-term storage of large amounts of data and programs
B. a device for entering alphanumeric data, as well as control commands
D. device for manipulator type
110. Floppy disks (floppies) are designed for ...
A. long-term storage of information, the volume of which exceeds 10 MB
B. displaying text and graphic information
C. transferring documents and programs from one computer to another, storing information that is not constantly used on a computer
D. recording information on magnetic tape cassettes
111. A hard drive is...
A. a device for storing large amounts of data and programs used when running a PC
B. a device for recording data and programs on magnetic tape cassettes
C. device for displaying text and graphic information
D. a device for controlling the operation of a personal computer according to a given program
112. A printer is a device for ...
A. transferring information from one computer to another
B. input graphic information
C. putting information on paper
D. Long-term storage of data and programs
113. CD-ROM is…
A. a device used only for writing information to a CD
B. a device for recording information on magnetic tape cassettes
C. a device for displaying information on a sheet of paper
D. a device used to read information from a CD and transfer it to a computer
114. The concept of computer science:
A. information processes occurring in complex systems
B. ways to perform arithmetic operations on a computer
C. Computing equipment such as calculator, manipulator, computer and computing
D. the branch of science and technology that investigates the issues of information processing using
modern technical means
E. answers a) and c)
115. Folder is...
A. program my computer
B. program explorer
C. is the name of a group of files combined according to some attribute
D. bulk file
E. collection of files and documents
116. What is a directory (directory or folder)?
A. this is the name of a group of files combined according to some attribute
B. this is the same as the disk drive
C. It is a storage device
D. It is a data processing software tool
E. this is a software and hardware system designed to generate information about
programs
117. Windows is:
A. application program
b. utility
C. driver
D. operating system
118. The line on which the start button is located is called:
a. toolbar
B. desktop
C. taskbar
d. label
E. answers a) and c)
119. What type of program are presentation preparation?
A. system software
B. Applied by
C. instrumental environments
d. operating system
E. Utilities
120. Spreadsheet is:
A. a set of numbered rows and columns named using letters of the Latin alphabet
B. set of named rows and numbered columns using Latin letters
C. collection of numbered rows and columns
D. a collection of rows and columns arbitrarily named by the user
Block A. Choose one answer.
A1. Which of the following input devices belongs to the class of manipulators:
- touchpad
- Joystick
- Microphone
- Keyboard
A2. You can save information before turning off your computer
- in RAM
- in external memory
- in the disk controller
A3. Persistent storage is used to store:
- user programs during operation
- especially valuable application programs
- especially valuable documents
- constantly used programs
- programs for booting a computer and testing its nodes
A4. The personal computer is...
- text processing device
- electronic number processing device
- electronic information processing device
A5. In which PC device is information processed?
- External memory
- Display
- CPU
A6. Printers are:
- matrix, laser, inkjet
- monochrome, color, black and white
- desktop, portable
A7. Computer architecture is
- technical description of computer device parts
- description of devices for input-output of information
- description software for computer operation
A8. Device for displaying text and graphic information on various hard media
- monitor
- Printer
- scanner
- modem
A9. Scanners are:
- horizontal and vertical
- internal and external
- manual, roller and flatbed
- matrix, inkjet and laser
A10. Graphics tablet (digitizer) - device:
- for computer games
- when carrying out engineering calculations
- to transfer character information to a computer
- for entering drawings, drawings into a PC
A11. Given: a = EA 16, b = 3548. Which of the numbers C, written in the binary system, satisfies the inequality a
- 11101010 2
- 11101110 2
- 11101011 2
- 11101100 2
A12. 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.
- 92 bits
- 220 bit
- 456 bit
- 512 bit
A13. Unicode encodes two bytes for each character. Determine the information volume of a word of twenty-four characters in this encoding.
- 384 bits
- 192 bits
- 256 bit
- 48 bit
A14. 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.
- 80 bit
- 70 bytes
- 80 bytes
- 560 bytes
A15. Calculate the sum of the numbers x and y, for x = A6 16 , y = 75 8 . Present the result in binary number system.
- 11011011 2
- 11110001 2
- 11100011 2
- 10010011 2
¬(The first letter of the name is a vowel → The fourth letter of the name is a consonant)?
- ELENA
- VADIM
- ANTON
- FEDOR
X | Y | Z | F |
1 | 1 | 1 | 1 |
1 | 1 | 0 | 1 |
1 | 0 | 1 | 1 |
- X v ¬ Y v Z
- X Λ Y Λ Z
- X Λ Y Λ ¬ Z
- ¬X v Y v ¬Z
A18. After starting Excel, an empty ... appears in the document window.
- workbook
- notebook
- table
- page
A19. The word with which the title of the program begins.
- program
- readln
- integer
- begin
A20. Determine the value of the variable c after the execution of the following program fragment.
a:= 5;
a:= a + 6;
b:= -a;
c:= a - 2*b;
- c=-11
- c=15
- c=27
- c=33
Block B
B1. Which of the following applies to computer output devices? Write the letters in your answer.
- Scanner
- Printer
- Plotter
- Monitor
- Microphone
- speakers
Answer: b, c, d, e
B2. Match
Purpose | Device | |
1. Input device | a) monitor | |
2. Output devices | b) printer | |
c) diskette | ||
d) scanner | ||
e) digitizer |
Answer: 1d,d 2a,b
AT 3. How many bits does the word "computer science" contain. Write only the number in your answer.
B4. Establish a correspondence between the concepts of the Pascal language and their description:
Answer: 1a,c 2e 3d 4e,b
AT 5. Note the main ways of describing algorithms.
- block diagram
- Verbal
- Through networks
- Using normal forms
- With the help of diagrams
Option 2.
Block A. Choose one answer.
A1. The device for inputting information from a sheet of paper is called:
- Plotter
- streamer
- Driver
- Scanner
A2. Driver is
- long-term storage device
- program that controls a specific external device
- input device
- output device
A3. When connecting a computer to the telephone network, the following is used:
- modem
- Fax
- scanner
- Printer
A4. Specify input devices.
- Microphone, keyboard, scanner, digital camera
- Mouse, light pen, hard drive
- Printer, keyboard, joystick
A5. Which PC device is designed to display information?
- CPU
- Monitor
- Keyboard
A6. External memory includes …….
- modem, disk, cassette
- cassette, optical disc, tape recorder
- disc, cassette, optical disc
A7. The processor includes:
- devices for recording information, reading information
- arithmetic logic unit, control unit
- input and output devices
- storage device
A8. A type of printer in which an image is created by mechanical pressure on paper through a ribbon of ink. Either symbol templates or needles are used, structurally combined into matrices.
- impact type (matrix)
- jet
- photoelectronic
A9. There are no monitors
- monochrome
- liquid crystal
- based on CRT
- infrared
A10. When you turn off the computer, all information is erased
- on CD-ROM
- in RAM
- in a floppy disk
A11. Given: a = E71 6 , b = 351 8 . Which of the numbers C, written in the binary system, satisfies the inequality a
- 1101010
- 11101000
- 11101011
- 11101100
A12. 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.
- 512 bit
- 608 bit
- 8 KB
- 123 bytes
A13. 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.
- 44 bits
- 704 bits
- 44 bytes
- 704 bytes
A14. 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?
- 200 bit
- 200 bytes
- 220 bytes
- 250 bytes
A15. The value of the expression 101 6 + 10 8 * 10 2 in binary is
- 1010 2
- 11010 2
- 100000 2
- 110000 2
A16. For which symbolic expression is the statement false:
First letter vowel → ¬ (Third letter consonant)?
- abedc
- becde
- babas
- abcab
X | Y | Z | F |
0 | 1 | 0 | 0 |
1 | 1 | 0 | 1 |
1 | 0 | 1 | 0 |
- ¬X v Y v ¬Z
- X Λ Y Λ ¬Z
- ¬X Λ Y Λ Z
- X v ¬Y v Z
A18. The lines in the workbook are denoted:
- Roman numerals
- Russian letters
- with Latin letters
- Arabic numerals
A19. What is the assignment command in PascalABC? Choose one of the answer options:
A20. Determine the value of the variable b after executing the following program fragment, where a and b are real (real) variables:
a:= -5;
b:= 5 + 7 * a;
b:= b / 2 * a;
- -75
Block B
B1. Which of the following applies to computer input devices? Write the letters in your answer.
- Scanner
- Printer
- Plotter
- Monitor
- Microphone
- speakers
Answer: a, d
AT 2. Match
Answer: 1d,d 2a,b
B3. How many bytes contains the word "information". Write only the number in your answer.
AT 4. Write down only those letters, the words under which denote Pascal data types.
- var
- begin
- real
- write
- integer
Answer: c, d
B5. Which of the following properties are the main properties of the algorithm?
- Efficiency
- mass character
- Correctness
- Certainty
3 option
Block A. Choose one answer.
A1. Printers cannot be:
- tablet
- matrix
- laser
- Inkjet
A2. "A program stored in external memory, after being called for execution, enters ..... and is processed ....".
- processor input device
- processor registers
- cpu processor
- processor memory
- file processor
A3. The minimum composition of a personal computer ...
- hard drive, floppy drive, monitor, keyboard
- monitor, keyboard, system unit
- printer, keyboard, monitor, memory
A4. When you turn off the computer, all information is erased
- on CD-ROM
- in RAM
- in a floppy disk
A5. External storage devices include..
- CPU
- Diskette
- Monitor
A6. Random Access Memory (RAM) is physically
- microchip
- floppy disk
- magnetic disc
A7. For proper operation peripheral device The driver for this device must be
- in RAM
- on hard drive
- on installation diskettes
- printed
A8. A type of printer in which the main element is the print head, which consists of nozzles to which ink is supplied.
- jet
- laser
- matrix
A9. Personal computer cases are:
- horizontal and vertical
- internal and external
- manual, roller and flatbed
- matrix, inkjet and laser
A10. Printers are:
- desktop, portable
- matrix, laser, inkjet
- monochrome, color, black and white
- based on CRT
A 11. How is the number 82 represented in the binary system?
- 1010010 2
- 1010011 2
- 100101 2
- 1000100 2
A12. 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.
- 28 bit
- 272 bits
- 32 KB
- 34 bits
A13. 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.
- 1024 bytes
- 1024 bits
- 512 bytes
- 512 bit
A14. Works in production automated system 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.
- 35 bytes
- 45 bit
- 55 bit
- 65 bytes
A15. Calculate the sum of binary numbers x and y if x = 1010101 2 and y = 1010011 2
- 10100010 2
- 10101000 2
- 10100100 2
- 10111000 2
A16. For which name is the statement true:
(Second vowel → First vowel) Λ Last consonant?
- IRINA
- MAKSIM
- MARIA
- STEPAN
A17. The symbol F denotes one of the following logical expressions from three arguments: X, Y, Z. A fragment of the truth table of the expression F is given (see table). What expression corresponds to F?
X | Y | Z | F |
0 | 0 | 0 | 1 |
0 | 0 | 1 | 0 |
0 | 1 | 0 | 0 |
- X Λ Y Λ Z
- ¬X Λ ¬Y Λ Z
- X Λ Y Λ ¬Z
- ¬X Λ ¬Y Λ ¬Z
Exam case.
Professor. How does a transformer work?
Student. Woo-o-o-o-o-o-o-o-o-o-o-o...
We have long been accustomed to personal. We turn them on and work, in fact, without thinking a little about how they are arranged and how they work. All this is due to the fact that PC developers and software developers have learned to create reliable products that do not give us reason to once again think about the design of a computer or programs serving it.
However, readers of the blog are probably interested in learning about how computers and software work. This will be the subject of a series of articles that are published under the heading "How a PC Works".
How a PC Works: Part 1: Processing Information
Computer for automating information processing processes. It is arranged accordingly in order to have all the possibilities for the successful fulfillment of its mission.
In order to process information in a computer, it is necessary to do the following basic operations with it:
– enter information to computer:
This operation is needed so that the computer has something to process. Without the possibility of entering information into a computer, it becomes, as it were, a thing in itself.
– store entered information in computer:
Obviously, if you give the opportunity to enter information into a computer, then you need to be able to store this information in it, and then use it in the processing process.
– process the entered information:
Here it must be understood that certain processing algorithms are needed to process the entered information, otherwise there can be no talk of any information processing. The computer must be equipped with such algorithms and must be able to apply them to the input information in order to "correctly" convert it into output data.
– store processed information,
As well as with the storage of the entered information, the computer must store the results of its work, the results of processing the input data so that they can be used in the future.
– output information from a computer:
This operation allows you to display the results of information processing in a readable form for PC users. It is clear that this operation makes it possible to use the results of information processing on a computer, otherwise these processing results would remain inside the computer, which would make their receipt completely meaningless.
The most important skill of a computer is the processing of information, since its beauty lies precisely in the fact that it can transform information. The entire device of a computer is due to the requirement to process information in the shortest possible time, in the fastest way.
Information processing on a computer can be understood as any action that transforms information from one state to another. Accordingly, the computer has a special device, called, which is designed exclusively for extremely fast data processing, with speeds reaching billions of operations per second.
CPU
The processor receives (takes) the data required for processing from a device designed for temporary storage of both input and output data. There is also a place in the RAM for storing intermediate data generated in the process of information processing. Thus, the processor both receives data from RAM and writes the processed data to RAM.
Random Access Memory (RAM)
Finally, for data input and output, a computer is connected that allows the input of information to be processed and the output of the results of this processing.
External hard drive, external DVD device, flash drive, keyboard, mouse
The processor and RAM work at the same speed. As mentioned above, the speed of information processing can be many millions and billions of operations per second. No external input and output device can operate at such speeds.
Therefore, for their connection to the computer, special I/O device controllers. Their task is to match the high speeds of the processor and RAM with relatively low input and output speeds.
These controllers are divided into specialized, to which only special devices can be connected, and universal. An example of a specialized controller device is, for example, a video card that is designed to connect a monitor to a computer.
CPU
The processor is the central unit of the computer, where information is processed.
It controls the operation of all devices and performs all logical and arithmetic operations.
The main unit of the processor is arithmetic unit
(ALU - arithmetic logic unit). It performs all operations on the data. The processor includes control device
, which controls all devices and monitors the sequence of command execution.
Currently, the processor is implemented in hardware in the form of LSI (large-scale integrated circuits). Modern PENTIUM processors contain millions of functional elements. The processor can process numerical, textual, graphic, video and sound information.
The processor works in close contact with a microcircuit called a clock generator (GTC). The GTS generates periodic pulses that synchronize the operation of all computer nodes. This is a kind of metronome inside the computer. The processor works to the rhythm of this metronome. The clock frequency is equal to the number of cycles per second. The cycle is the time interval between the start of the current pulse and the start of the next one. A certain number of clock cycles is allocated for each operation to be performed by the processor. It is clear that if the "metronome" beats faster, then the processor works faster. The clock frequency is measured in megahertz - MHz. A frequency of 1 MHz corresponds to a million cycles per second. Here are some characteristic clock frequencies of microprocessors: 130 MHz, 266 MHz, 1000 MHz, 2000 MHz, 3 GHz, etc.
computer memory
All information entered enters the storage device or machine memory, where it is stored until the moment when it is needed.
The carrier of information is the physical environment in which it is recorded.
Paper, photographic film, brain cells, punched cards, punched tapes, magnetic tapes and disks or computer memory cells can act as a carrier. Modern technology offers more and more new types of information carriers. To encode information, they use the electrical, magnetic and optical properties of materials. Carriers are being developed in which information is recorded even at the level of individual molecules.
Computer memory can be internal or external. Internal memory includes permanent and operational.
Persistent memory
(ROM - Read Only Memory). A feature of the ROM is that information can only be read from it during operation, but it cannot be written. A characteristic feature of the ROM is the preservation of information when the computer's power is turned off. The information recorded in the ROM is entered once (usually at the factory) and is stored permanently (when the computer is turned on and off) throughout the entire period of PC operation and cannot be changed during operation. ROM is fast, non-volatile memory. The ROM stores information, the presence of which is constantly needed in the computer. Usually these are components of the operating system (hardware control programs, computer boot program, etc.)
In modern PCs, there is another type of fast memory that has a special purpose. This is video memory. Video memory stores the code of the image displayed on the display.
RAM
(OP) is a computer device designed to store data (source, intermediate and final) and programs (a set of instructions). Everything you enter into a computer is stored in RAM (Random Access Memory). The English name for RAM is Random Access Memory (RAM), which translates as "random access memory". This name emphasizes the fact that the processor can access memory cells in any order, while the time to read / write information for all cells is the same (it is measured in microseconds).
Information stored in RAM can be changed. When you turn off your PC, all information in RAM is erased. This memory is called operational, because. it allows you to record and transmit information at a very high speed. However, the amount of RAM is limited, so there is a need to connect external memory. Physically, OP is made in the form of LSI with different information capacity.
To speed up data access, a special device called a cache is used. Cache
- this is a "super-operational" memory of a relatively small volume (usually up to 520,000 characters), built on a different element base than RAM. The cache stores the most frequently used areas of RAM. When the processor accesses memory, it first searches for the necessary data in the cache. Since the access time to cache memory is several times less than to RAM, the average memory access time decreases.
External memory
as if it replaces books with programs and algorithms described in them. External memory devices or VZU (external storage devices) include:
Floppy disk drives
Hard Disk Drives
Laser CD drives
Magneto-optical systems
streamers
Flash drives
The main purpose of external memory is long-term storage of a large amount of information. For the user, some technical and economic indicators of external storage devices and information carriers are essential: information capacity, information exchange rate, reliability of its storage and cost.
Magnetic media
The first computers used ordinary tape recorders as external memory. Today, tape recorders are used only to back up the contents of hard magnetic disks (MDs). on disks, information can be lost “thanks to” computer “viruses”. An assistive tape recorder that records information from a computer onto a special magnetic tape cassette (ML) is called streamer.
The streamer cassette has a very large capacity and allows you to store information from the entire hard disk.
The basis for recording, storing and reading information on magnetic media is the magnetic principle: during the recording process, the media moves relative to the head with a core of magnetically soft material, electrical impulses create a magnetic field in the head, which sequentially magnetizes or does not magnetize the elements of the media.
When reading information, the magnetized sections of the carrier cause a current pulse in the head, which makes it possible to qualitatively recognize information. The method of recording and reading information on ML and MD is similar to the operation of a conventional tape recorder.
HDD
is a plate of non-magnetic material, on the surface of which a magnetic layer is deposited. Its average uptime is hundreds of thousands of hours. Hard magnetic disks consist of several disks placed on the same axis and rotating at a high angular velocity (several thousand revolutions per second), enclosed in a metal case. The read/write heads move across all disk surfaces at once.
A hard magnetic disk (HMD), or hard drive, is designed for permanent storage of information used when working with a computer: operating system programs, frequently used software packages, text editors, etc. Modern hard disk drives have a rotation speed of 3600 to 7200 rpm . This may be a glass disc (with a metallic surface film, such as cobalt), not sensitive to temperature. Information capacity - up to 48 billion characters.
A relatively new concept: a flash drive. This is a device for long-term data storage, with the possibility of multiple rewriting, implemented on memory chips (that is, just like RAM). Advantages: low power, reliability in operation, small size, shock resistance, absence of mechanical and moving parts, memory capacity from 2 to 200 MB and even up to 1.7 GB. The disadvantage is the high price of the device. Despite the high cost, it seems that flash drives will eventually replace hard drives.
Floppy disks are used for the exchange of programs between computers and for the delivery of software products. Flexible MD (GMD) are designed to transfer documents and programs from one computer to another, store archival copies and information that is not constantly used on a computer.
Floppy disks are placed in a thick paper envelope or in a plastic case. There is a hole in the center of the disc to allow the disc to rotate in the drive. The protective envelope has an elongated hole through which information is written / read. On the side edge of the floppy disks there is a small cutout that allows recording, but if the cutout is sealed, recording becomes impossible (the disk is protected). On some floppy disks, write protection is provided by a safety latch in the lower left corner of the plastic case.
Flexible MD with a diameter of 5.25 inches were used until the mid-80s of the 20th century and could store up to 1.5 million characters of information. 5.25-inch floppy disks did not provide good physical protection for the media. Currently, 3.5-inch GMDs are still in use, which have a capacity of 1.8 million characters. Protection of the magnetic layer is especially relevant, so the disk itself is hidden in a durable plastic case, and the contact area of the heads with its surface is closed from accidental touches by a special shutter, which automatically moves away only inside the disk drive.
Any magnetic disk is not initially ready for operation. To bring it into working condition, it must be formatted, that is, the disk structure must be created. Information on the GMD is stored on magnetic concentric tracks, divided into sectors, marked with magnetic marks, and the GMD also has cylinders - a set of tracks located one above the other on all working surfaces of the disks. All the tracks of the magnetic disks on the outer cylinders are larger than those on the inner ones. Therefore, with the same number of sectors on each of them, the recording density on the inner tracks should be greater than on the outer ones. The number of sectors, sector capacity, and, consequently, the information capacity of the disk depend on the type of drive and formatting mode, as well as on the quality of the disks themselves.
The disadvantages of magnetic media are the ability to destroy the magnetic layer with frequent reading of information and from the effects of magnetic fields and the phenomenon of "chewing" the tape. The advantage is the ability to record information many times.
Optical media
There are optical disc drives (CD-ROM), where information is recorded by a laser. Outwardly, they are no different from audio CDs. CD-ROM disks (Compact Disk Read Only Memory) have a capacity of up to 3 billion characters of information, high reliability of information storage, and durability (the predicted service life of its high-quality performance is up to 30-50 years).
This is interesting!The CD-ROM manufacturing process consists of several steps. First, information is prepared for the master disk (the first sample), it and the replication matrix are made. Encoded information is applied to the master disk by a laser beam, which creates microscopic depressions on its surface, separated by flat areas. Digital information is represented by an alternation of depressions (non-reflective spots) and light-reflecting islands. Copies of the negative of the master disc (matrix) are used to press the CDs themselves. The replicated CD consists of reflective and protective layers. Finely dusted aluminum is usually used as a reflective surface. Unlike magnetic disks, which have concentric circle tracks, a CD-ROM has only one physical track in the form of a spiral running from the outer edge of the disc to the inner (like on a phonograph record).
CD-ROM drives use the optical principle of reading information. The laser beam falls on the surface of a rotating CD-ROM disk and the beam is reflected in it with an intensity corresponding to the values 0 and 1. The laser beam hits the light reflecting island, is deflected by the photodetector, which interprets it as a binary unit. The laser beam falling into the cavity is scattered and absorbed - the photodetector fixes a binary zero.
To load a CD into the drive, either one of the varieties of the sliding panel or a special transparent cassette is used. They produce devices that allow you to independently record special CDs. Unlike conventional discs, these discs have a reflective layer of gold. These are the so-called rewritable CD-Rs. Such discs usually serve as master discs for further replication or archiving.
Capacitance increase reserve - increasing the recording density by reducing the laser wavelength. This is how CDs appeared, capable of storing almost 5 billion characters of information on one side and 10 billion characters on two sides. It is also planned to create a two-layer recording scheme, i.e. when on one side of the media there are two surfaces spaced in depth with recorded data. In this case, the information capacity of the CD increases to 9 billion characters on one side.
The disadvantage of a CD-ROM disc is that information is written to the media only once. The advantage of a CD-ROM disc is the endless reading of information without loss.
It seems that CD-ROMs, which have become familiar, will soon become a thing of the past. Rewritable CDs (CD-RW, CD-ReWritablie) are already widely used. CD-RW discs removed the fundamental limitation of CD-ROM, associated with the possibility of only one-time recording of information. Recording on a CD-R disc is possible only once and is done by the user using a compact and inexpensive recording drive.
Digital laser DVDs appeared. Their main difference is a higher recording density. Thus, the dominant computer market is a disk with a diameter of 120 mm and a capacity of up to 5 billion characters. It is believed that the capacity of DVDs can reach 15 billion characters.
A distinction is made between DVD-ROM and DVD-RAM discs. DVD-ROM is read-only. DVD-RAM for reading and writing. To read DVDs, you need a special drive that also reads CD-ROMs.
One of the achievements of the 20th century is magneto-optical disks. They use the advantages of magnetic and optical media: multiple recording and multiple reading. Magneto-optical disks may prove to be one of the most viable devices for data storage. The fact is that CD-ROMs are convenient for storing information, and in working with it they turn out to be slower than hard magnetic disks. Therefore, information from CDs is usually copied onto an MD, with which they work. Such a system is not suitable if the work is related to databases, which, due to the large information capacity, are just more profitable to place on CD-ROM. In addition, the CDs currently used in practice are not rewritable. Magneto-optical disks are devoid of these shortcomings. It combines the achievements of magnetic and optical technologies. They can write information and quickly read it. They retain all the advantages of the GMD (portability, the possibility of separate storage, increase in computer memory) with a huge information capacity.
In magneto-optical systems, magnetic recording is made on the surface of a compact disc, which is preliminarily strongly heated by a laser beam. The first magneto-optical disks looked like a 3.5-inch floppy disk. Then 5.25-inch disks were created, which also fit in a plastic case. After that, magneto-optical disks appeared without a case, i.e. exactly the same as conventional laser audio discs and these achievements have been mentioned above.
Information input-output devices
Information input-output devices organize a dialogue between the user and the computer.
In order for a computer to perform useful information processing functions, it must first be introduced. The keyboard is the most famous and widespread input device for information in a computer. At the physical level, it is a set of mechanical sensors that perceive pressure on the keys and close a certain electrical circuit in one way or another. The graphical manipulator - "mouse" also belongs to the information input devices in the computer. It allows you to control the state of objects displayed on the screen: menus, light buttons, etc. A variation of the graphical “mouse” manipulator is the “trackball”, here the movement of the manipulator is carried out using a large ball inside. It does not require a rug, does not take up much space on the table, the ball is rotated by hand.
There are a large number of other mouse designs, such as:
1. Wireless
mouse - signals from the mouse are transmitted using a radio transmitter.
2. Optical
mouse - uses a special mat and a beam of light instead of a ball.
3. Foot
mouse.
Joystick
(used in game consoles) enters the coordinate-numeric information necessary for the implementation of games with the help of fingers; graphics tablet (digitizer)
provides data entry (coordinates of points and curves) with high accuracy; device "light pen"
, which captures and moves a point or cursor on the display screen, also allows information to be entered into the computer; scanner
- an input device that scans any drawing line by line and transfers information about it to a personal computer (used in publishing houses, in well-equipped photo labs).
The principle of operation of the scanner is as follows: the scanned image is illuminated with white light. Reflected light through a reducing lens falls on a photosensitive semiconductor element. Each scan line corresponds to certain voltage values on it, then the voltage values \u200b\u200bare converted into digital form. Scanners are handheld, flatbed and drum. Manual ones are almost non-existent. Drum scanners provide the highest quality. Distinguish between black and white and color scanners. The scanner enters the image as a set of points, specifying a color number for each coordinate. According to these data, a copy of the image is entered into the memory. If you enter text using a scanner, you need special programs.
In the early days of computer technology, there were devices for input-output of information from punched cards and punched tapes
. People of the old school remember well rolls of punched tapes and decks of punched cards, which were chopped into noodles for a few seconds by a faulty reader. They had serious shortcomings: the paper was quickly torn, and it was difficult to correct mistakes.
Printing devices
, reminiscent of ordinary typewriters, were previously also used for input / output of information. But due to the strong noise during operation of these devices, users abandoned them.
Display
is a device for input-output of textual and graphic information, as it includes monitor
And keyboard
. Three types of monitors are in use: flat-screen liquid crystal monitors, gas-plasma monitors, and cathode-ray tube monitors. Monitors are available in color and monochrome.
Printers
print documents and programs on paper (there are several types of printers: matrix
where printing is done with thin metal rods striking the paper through an ink ribbon; jet
where printing is carried out by microdrops of special ink blown onto paper using nozzles; laser
printers that provide the highest quality prints use the principle of xerography: the image is transferred to paper from a special drum, to which dye particles are electrically attracted). Other devices for outputting information to paper - plotters
print drawings and graphs on paper. The speakers are designed for acoustic output (playback) of sound information, both already stored in the PC memory in the form of files, and coming to the PC from external music devices. All these devices are called peripheral.
To enter information into computers, digital video cameras
And cameras
, speech input and output are increasingly used. It is hard to imagine what will become common tomorrow. Portable computers without keyboards have appeared that can recognize and enter handwritten text. The image can be displayed on data helmet
- two miniature screens in front of the eyes create a stereo image. info gloves
can transmit images of human fingers to a computer and, receiving information from a computer, resist human movements. infosuits
are able to perceive the position of the human body and imitate the touch or pressure on the human skin by computer commands. All these information devices
allow the creation of so-called artificial realities
(virtual world), where a person operates in an imaginary world created by a computer, receiving through his senses the corresponding complexes of sensations.
a) external memory b) display; c) processor; d) keyboard.
20. MODEM- this device:
a) to store information;
b) to process information at a given time;
c) to transmit information via telephone communication channels;
d) to print information.
21. information output? a) working memory; b) display; c) mouse; d) keyboard
22. What computer device is intended forinput information? a) a printer b) display; c) processor; d) keyboard.
2 3. RAM serves:
a) to store information;
b) for information processing;
c) to run programs;
d) to process one program at a given time.
2 4. Plotter - this device:
a) for reading graphic information;
b) for input;
c) for withdrawal;
d) to scan information.
25. External storage devices include:
a) a processor b) diskette:
c) monitor; d) hard drive. 2 6. The "mouse" manipulator is a device:
a) output;
c) reading information;
d) information scanning.
27. Specify the minimum required set of lipsroystvo, designed to operate a computer:
a) printer, system unit, keyboard;
b) processor, RAM, monitor, keyboard;
c) processor, streamer, hard drive;
d) monitor, hard drive, keyboard, processor .
28. External memory serves:
a) for storing operational, frequently changing information in the process of solving a problem;
b) for long-term storage of information, regardless of whether the computer is working or not;
c) for storing information inside the computer;
d) to process information at a given time.
What is an operating system
The operating system is the program that loads when you turn on your computer. It produces a dialogue with the user, manages the computer, its resources (RAM, disk space, etc.), launches other (application) programs for execution. The operating system provides the user and application programs with a convenient way to communicate (interface) with computer devices.
The main reason for the need for such a program as an operating system is that the elementary operations for working with computer devices and managing computer resources are very low-level operations, and the actions that a user and application programs need, in fact, consist of several hundred or thousands of such elementary operations.
There are about a dozen floppy disk formats, and the operating system must be able to work with all of these formats. For the user, work with diskettes of various formats should be carried out in exactly the same way;
A file on floppy disks occupies certain sections, and the user does not need to know anything about which ones. All functions for maintaining file allocation tables, searching for information in them, allocating space for files on diskettes are performed by the operating system, and the user can know nothing about them;
During the operation of the copy program, several dozens of different special situations can occur, for example, a failure to read or write information, disk drives are not ready for reading or writing, there is no space on the diskette for the file being copied, etc. For all these situations, it is necessary to provide appropriate messages and corrective actions. The operating system also performs auxiliary activities such as copying or printing files. In addition, the operating system loads all programs into RAM, transfers control to them at the beginning of their work, performs various auxiliary actions at the request of executing programs, and frees the RAM occupied by programs when they complete.
User dialog with MS DOS
When MS DOS is ready for a dialogue with the user, it displays a prompt on the screen, for example, or C:\>
This means that MS DOS is ready to receive commands.
The user's dialogue with MS DOS is carried out in the form of commands. Each user command means that MS DOS must perform some action, such as printing a file or displaying a directory listing on the screen.
An MS DOS command consists of a command name and possibly options, separated by spaces. The MS DOS command name and parameters can be typed in both uppercase and lowercase Latin letters. Entering each command ends with a keystroke
Basic components of MS DOS
The MS DOS operating system consists of the following parts.
The basic input/output system (BIOS) is located in the computer's read-only memory (read-only memory, ROM). This part of the operating system is "built into" the computer. Its purpose is to perform the simplest and most versatile operating system services associated with I/O. The basic input-output system also contains a test of the functioning of the computer, which checks the operation of the memory and devices of the computer when it is turned on. In addition, the basic input-output system contains a program to call the boot loader of the operating system.
The operating system loader is a very short program located in the first sector of each floppy disk with the MS DOS operating system and a hard disk (hard drive). The function of this program is to read two more operating system modules into memory, which complete the MS DOS boot process.
Disk files IO.SYS and MSDOS.SYS (however, they may be called differently, for example, IBMBIO.COM and IBMDOS.COM, the names change depending on the version of the operating system). They are loaded into memory by the operating system loader and remain in the computer's memory constantly. The IO.SYS file is an addition to the basic I/O system in ROM. The MSDOS.SYS file implements the basic high-level services of MS DOS.
The MS DOS command processor processes commands entered by the user. The command processor is located in the disk file COMMAND.COM on the disk from which the operating system is loaded. Some user commands, such as type.dir or copy, are executed by the shell itself. Such commands are called internal. To execute the remaining (external) user commands, the command processor searches the disks for a program with the appropriate name, and if it finds it, it loads it into memory and transfers control to it. At the end of the program, the command processor removes the program from memory and displays a message about the readiness to execute commands (MS DOS prompt).
External MS DOS commands are programs that come with the operating system as separate files. Such programs perform maintenance actions such as formatting floppy disks, checking disks, etc.
Device drivers are special programs that complement the MS DOS I / O system and provide maintenance for new devices or non-standard use of existing devices. just like with disk. Drivers are loaded into the computer's memory when the operating system boots, their names are specified in a special CONFIG.SYS file. This scheme makes it easier to add new devices and allows you to do this without affecting the MS DOS system files.
Initial loading of MS DOS is performed automatically when the computer is turned on, when you press the "Reset" key on the computer case (not all computer models have such a key), and also when you simultaneously press the keys (Ctrl), (Alt) and (Del) on keyboard. To boot MS DOS, you must have a floppy disk loaded with the MS DOS operating system installed on the floppy drive A or that the computer has a hard disk (hard drive) with the MS DOS operating system written on it. As a rule, the operating system on hard disks MS DOS is written by the computer vendor.
At the beginning of the download, the hardware check programs that are in the permanent memory of the computer work. If they find an error, they display the error code on the screen. If the error is not critical (that is, allowing the continuation of work), then the user is given the opportunity to continue the download process by pressing the (F1) key on the keyboard. If the fault is critical, then the download process stops. In any case, the situation and the error code generated should be reported to computer maintenance specialists.
After the hardware test programs finish running, the boot program tries to read the operating system loader program from the disk installed in drive A. If there is no floppy disk on drive A, then the operating system will be loaded from the hard disk (hard drive). If drive A does not contain a diskette with the operating system, but some other diskette, an error message
Non-system disk or disk error
Replace and strike any key when ready
(non-system drive or disk error.
Change disk and press any key)
You should put a diskette with the operating system on drive A if you want to boot the computer from a floppy disk, or open the drive door or remove the diskette from the drive if you want to boot the computer from a hard disk (hard drive). After that, press any alphanumeric key, space or (Enter) to continue the download process.
Overview of MS DOS Commands
The following is a summary of MS DOS commands: names and descriptions of the purpose of the commands. This information provides only a very general idea of what MS DOS commands do.
There are two types of MS DOS commands: internal and external.
Internal commands are executed by the MS DOS processor itself (the COMMAND.C program. These commands are as follows:
BREAK-set the combination input check mode (Cntrl-C).
cd-change current directory or show current directory name.
CLS-clear monitor screen.
COPY-copying files.
CTTY-change I/O device for MS DOS commands.
DATE - get or change the current date.
DEL - deleting files.
DIR - Give a list of files in a directory.
ECHO - issue a message from a batch batch file.
EXIT - end the work of the command processor COMMAND.COM.
FOR-organization of cycles.
GOTO jump to a label in a batch batch file.
IF condition check in a batch batch file.
MD-Create a new directory.
PATH - set the list of directories to search for commands.
PAUSE - Pause the execution of a batch batch file.
PROMPT - set MS DOS prompt type.
REM comment in a batch batch file.
ren-change filename.
rd-delete directory.
SET - set environment variable.
SHIFT-shift the parameter numbers of a batch batch file.
TIME - Get or set the current time.
TYPE-file viewing (file input on the screen).
VER - give the version number of MS DOS.
VERIFY - set or cancel the mode of checking the correctness of writing to disk.
VOL output of the disk label.
External MS DOS commands are programs supplied with the operating system as separate files. These commands are:
APPEND - set additional directories for data search.
ASSIGH - assign another logical name (letter) to the drive.
ATTRIB - Set or show file attributes.
BACKUP - create archive copies of files.
CHKDSK - check the disk for the correct file system.
COMMAND - start the MS DOS command processor.
DEBUG - view, modify, disassemble files.
DISKCOMP - Comparison of floppy disks.
DISKCOPY - copy diskettes.
EDLIN is a primitive text editor.
EXE2BIN - Convert an EXE file to binary code.
FASTOPEN-acceleration of file opening.
FC file comparison.
FDISK partitioning a hard disk.
FIND - search for a substring in files.
FORMAT-formatting (initialization) of the disk.
GRAFHICS - preparation for printing a graphic copy of the screen.
LABEL - find out or set a disk label.
LINK link editor.
MD-Create a new directory.
MODE-set device operating modes.
MORE-page output on the monitor screen.
PRINT-printing text files on the printer in the "background" mode.
RECOVER - restore a file containing "bad" sections.
REPLACE - replace files with their new versions.
SHARE - set the multi-user mode for using files.
SORT sorting data.
SUBST - Replace directory name with drive name.
SYS - copy system files to disk.
TREE - display the directory structure on disk.
XCOPY - copy files (has more options than COPY)
Task: Describe the process of creating the specified directory tree. In the specified folders, create a test file Address and Information. Glue them together and place them in the specified folder. Rename it to General. Destroy all created folders and directories.
What device processes the information. In what device of the computer is information processed? computer processor
A. keyboard B. external memory C. display D. processor 107. Video memory is… A. electronic memory for long-term storage of programs and data B. memory for storing parameters...