Web carrier that. Regeneration of RAM. Storage drives on hard magnetic disks

Media information- Physical environment directly storing information. The main carrier of information for a person is its own biological memory (human brain). Human memory can be called RAM. Here the word "Operational" is synonymous with the word "fast". Accidental knowledge is reproduced by a person instantly. We can still be called internal memory, because its carrier is the brain - is inside us.

Media information- A strictly defined part of a specific information system that serves for intermediate storage or information transmission.

The basis of modern information technologies is a computer. When it comes to computer, we can talk about information carriers as external storage devices (external memory). These information media can be classified according to various features, for example, by type of execution, the material from which the carrier is made, and the like. Here is one of the options classification of media information:

Ribbon media information

Magnetic tape - Magnetic recording medium, which is a thin flexible tape consisting of the base and magnetic working layer. The working properties of the magnetic tape are characterized by its sensitivity when recording and distorting the signal in the process of recording and playback. The most widely used multilayer magnetic tape with a working layer of needle particles of magnetically solid powders of gamma-oxide oxide (U-FE2O3), chromium dioxide (CRO2) and iron oxide, modified by cobalt, oriented in the direction of magnetization during recording.

Disc media information Refer to motor media with direct access. The concept of direct access means that the PC can "contact" to the track on which a plot with the search for information begins or where new information needs to be recorded.

Drives on disks are most diverse:

Drives on flexible magnetic disks (NGMD), they are floppy disks, they are floppy disks

Storage devices on hard magnetic disks (NGMD), they are hard drives (people are simply "screws")

Drives on optical CDs:

CD-ROM (Compact Disk Rom)

In drives on flexible magnetic disks (NGMD or diskettes) and storage devices on rigid magnetic disks (NGMD or Winchesters), a magnetic principle is based on the record, storage and reading of information, and in laser drives - an optical principle.

Flexible magnetic discsplaced in the plastic case. Such a carrier of information is called a floppy disk. The diskette is inserted into the drive rotating a disk with a constant angular speed. The magnetic head of the drive is installed on a specific disk concentric path for which information is recorded (or read) information.

The information container floppy disks is small and is only 1.44 MB. The speed of recording and reading information is also small (about 50 kb / s) due to the slow rotation of the disk (360 rpm).

Hard magnetic discs.

Hard disk (HDD - Hard Disk Drive) refers to non-free disk magnetic drives. The first hard disk was developed by IBM in 1973 and had a capacity of 16 KB. Rigid magnetic discs are several dozen discs placed on one axis enclosed in a metal housing and rotating with high angular velocity. The recording speed and reading of information from hard drives is sufficiently large (about 133 MB / s) due to the rapid rotation of the disc (7200 rpm).

During the computer, there are failures. Viruses, power supply interruptions, program errors - all this can cause damage to information stored on your hard disk. Damage to the information does not always mean her loss, so it is useful to know how it is stored on the hard disk, because it can be restored. Then, for example, in the event of damage to the virus of the boot area, it is not necessary to format the entire disk (!), And, restoring the damaged place, continue to work with the preservation of all its priceless data.

In hard disks, quite fragile and miniature elements are used. To save the information and performance of hard drives, you need to protect them from shocks and sharp changes in spatial orientation during operation.

Laser drives and discs.

In the early 80s, the Dutch Firm "Philips" announced the revolution in the field of sound reproduction. Her engineers came up with what is now enjoying great popularity - these are laser disks and players.

Laser drives use the optical principle of reading information. On CD Laser Discs (CD - Compact Disk, CD) and DVD (DVD - Digital Video Disk, Digital Video Engine), information is recorded on one spiral track (both on a recorded) containing alternating areas with different reflectivity. The laser beam falls on the surface of the rotating disk, and the intensity of the reflected beam depends on the reflective ability of the track section and acquires the values \u200b\u200b0 or 1. To preserve information, laser discs need to be protected from mechanical damage (scratches), as well as contamination. The laser disks store information that was recorded on them in the manufacturing process. The recording on them is not possible. There are such discs by stamping. There are CD-R and DVD-R discs information on which can be recorded only once. On CD-RW and DVD-RW disks, information can be recorded / overwritten repeatedly. Discs of different types can be distinguished not only on labeling, but also in the color of the reflective surface.

Flash memory based devices.

Flash memory is a non-volatile memory type that allows you to record and store data in chips. Flash-memory-based devices do not have moving parts in their composition, which ensures high data safety when used in mobile devices.

Flash memory is a microcircuit placed in a miniature case. To record or read information, drives are connected to a computer via USB port. The information capacitance of memory cards reaches 1024 MB.

Information media are distributed in four parameters: the nature of the media, its purpose, the number of recording cycles and durability.

By nature, information carriers are substantive and biochemical. The first are those that you can touch, take in hand, move from place to place: letters, books, flash drives, discs, finds of archaeologists and paleontologists. The seconds have a biological nature and cannot be physically touching them: genome, any part of it - RNA, DNA, genes, chromosomes.

For the purpose of information, media is distributed on specialized and widespread. Specialized are those that are created only for one type of storage of information. For example, for digital recording. And a wide assignment is a carrier to which you can record information in different ways: the same paper, on it and write, and draw.

In terms of the number of recording cycles, the carrier is one-time or multiple. On the first one can write information only once, on the second - a lot. An example of a single information carrier is a CD-R disc, and the CD-RW disk is already referred to a multiple.

The durability of the carrier is the time it will store information. Those are considered short-term, inevitably destroy: if you write something on the sand in the water, the wave will wash the inscription in half an hour or an hour. And long-term can destroy only a random circumstance - a library or a flash drive suddow will suddenly fall into the sewer and breaks in water for many years.

Make media of information from four types of material:

paper from which earlier cards were made and punched, and the pages of books do now;
plastic for optical disks or tags;
magnetic materials desired for magnetic tapes;
semiconductors that are used to create computer memory.

In the past, the list was richer: information carriers were made of wax, fabrics, from bark, clay, stone, bones and many other things.

To change the structure of the material from which the information carrier is created, 4 types of influences are used:

mechanical - sewing, thread, drilling;
electrical - electrical signals;
thermal - burning;
chemical - etching or staining.

From the carriers of the past, the chassis were cardiac cards and punges, magnetic tapes, and then 3.5-inch floppy disks.

Perfoocards were made of cardboard, then pushed in the right places so that the holes in the cardboard reminded the pattern, and read information from them. And punctuate appeared later, were paper and used in the telegraph.

Magnetic ribbons covered the popularity of perfoch-roll and punched to zero. Such ribbons could also be stored, and play information - play recorded songs, for example. At the same time, tape recorders appeared, on which the cassettes and coils could be placed. But the shelf life of the magnetic tape was modest - up to 50 years.

When disks appeared, magnetic tapes went into the past. The floppy disks were small, 3.5 inches, and could store up to 3 MB of information. However, they were sensitive to magnetic effects, and they did not have time to have time for the needs of people - they needed carriers that could store much more data.

Now there are many such media: external hard drives, optical discs, flash drives, HDD boxes and deleted servers.

external HDs

External hard drives are packed in a compact housing, where there are one or two USB adapters and vibration protection system. They can store up to 2 TB of information.

easy to connect: Do not turn off the computer, messing with the power cable and SATA - on external hard drives there is a USB0 interface, they are connected as ordinary flash drives;
easy to transport: such devices are very small, they can easily take on a journey, you can even wear in your pocket, and they are quite simple to connect them to the home theater;
you can connect as many hard drives to the computer as USB ports.

information transmission rate is lower than SATA-connected;
need an increased power supply, so a double USB cable is required;
the plastic case, which means, during operation, we can hear clicks or other noise.

However, if the disk is in a rubberized metal case, no one will hear noise.

External hard drives are portable (2.5) and desktop (3.5). The interface can be exotic - FireWire or bluetooth, but such more expensive, they are less common and need an additional power supply.

Optical disks

These are CDs, laser disks, HD-DVDs, mini-disks and Blu-ray. Information from such discs is read by optical radiation, so they were called.

An optical disk is four generations:

the first is a laser, compact and mini-disk;
second - DVD and CD-ROM;
third - HD-DVD and Blu-ray;
fourth - Holographic Versatile Disc and Superrens Disc.

CDs now hardly use. They have a small volume - 700 MB, and the data from them reads the laser beam. CDs were divided into two types: those on which nothing could be written (CD), and those on which it was possible to write (CD-R and CD-RW).

DVDs externally the same as CDs, but they have much more. DVDs have several formats, the most popular DVD-5 is considered 4.37 GB and DVD-9 by 7.95 GB. Such discs are also R - for a single record, and RW - for repeated recording.

Blu-ray discs, having the same size as CD and DVD, accommodate much more data - up to 25 and to 50 GB. Up to 25 are discs with one layer of information record, and up to 50 - with two. And they are also divided into R - a single recording, and Re - recording multiple.

Flashki

The flash drive is a very small device that is with memory up to 64 GB and more. The flash drive computer is connected via the USB port, the speed of reading and writing is high, the plastic housing. Inside the flash drive, an electronic board with a memory chip.

The USB flash drive can be connected to a computer and TV, and if it is in Micro-CD format, then to the tablet or smartphone. Scratches and dust that could destroy optical discs, flash drive is not terrible - she has little susceptibility to external influences.

HDD boxes

This is an option that allows the use of regular hard disks of stationary computers as external. HDD Boxing is a plastic box with a USB controller, where you can put a regular hard disk and easily transfer information directly, avoiding additional copying and insert.

HDD Boxing is much cheaper than an external hard disk, and it is very useful if you need to transfer a large amount of information to another computer or even almost the entire partition of the hard disk.

Remote servers

This is a virtual storage method. The information will be on the remote server, connect to which you can from the computer, and from the tablet, and from the smartphone, you only need to have access to the Internet.

With physical information carriers, there is always a risk of losing the data, since the flash drive, a hard or optical disc can break. But with a remote server there is no such problem - the information is stored securely and so long as it is necessary for the user. In addition, on remote servers there is a backup storage in case of unforeseen situations.

Tip 2: Views of information media, their classification and characteristics

To lead economic activities, engage in science and art, a person at all times needed carriers of information. For this purpose, a variety of materials and devices were used. The choice of specific media was determined by the availability of materials and the level of technology development.

From the history of the development of information carriers

In the era of the formation of human society, people grabbed the walls of the cave to fix the information they need. Such a "database" would fit entirely. Yes Flash map size in megabytes. However, over the past few tens of thousands of years, the amount of information that is forced to operate a person essentially increased. Now disk drives and cloud data warehouses are widely used.

It is believed that the history of information recording and its storage began about 40 thousand years ago. The surfaces of the cliffs and walls of the caves have retained the images of the representatives of the animal world of the late Paleolithic. Much later, the coat includes plates from clay. On the surface of such an ancient "tablet", a person could apply images and make recordings by a pointed stick. When the clay composition was dried, the recording was fixed on the carrier. The lack of clay shape of storage of information is obvious: such signs were different and disadvantaged.

Approximately five thousand years ago in Egypt began to use more perfect media - papyrus. The information was recorded on special sheets that were made from specially treated plants stalks. This type of data storage was more perfect: papyrus sheets are easier than clay plates, it is much more convenient to write on them. This type of storage has lived in Europe until the XI century new era.

In another part of the world - in South America - ingenious incostees invented a novel letter with meanwhile. Information in this case was fixed using nodes, which in a certain sequence were tied on the thread or rope. There were whole "books" from the nodules, where information on the number of people's population of the Empire was recorded, the tax fees, the economic activities of the Indians.

Subsequently, paper has become the main carrier of information on the planet for several centuries. It was used to print books and media. At the beginning of the XIX century, the first perfocards began to appear. They were made of dense cardboard. These primitive machine carriers have become widely used for a mechanical account. They found use, in particular, when conducting the censuses of the population, they were used to control weaving machines. Humanity closely approached the technological breakthrough, which occurred in the 20th century. Electronic equipment came to replace mechanical devices.

What is information carriers

All material objects are capable of carrying any information. It is believed that information carriers are endowed with real properties and reflect certain relations between objects of reality. The material properties of objects are determined by the characteristics of the substances from which the carriers are performed. The properties of relations are depending on the qualitative features of the processes and fields by which the information carriers are manifested in the material world.

In the theory of information systems, it is customary to divide the carriers of information on origin, form and size. In the simplest case, media are divided into:

local (for example, hard disk personal computer);
alienated (removable disks and discs);
distributed (they can be considered communication lines).

The last form (communication channels) can be considered as media and the medium for its transfer.

In the most general sense, media can be considered different objects in their own form:

paper (books);
plates (photoflaxes, gramophone plates);
films (photo-, film);
audio cassettes;
microfilm (microfilm, microfish);
video tapes;
cDs.

Many media are known since ancient times. These are stone plates with images deposited on them; clay tablets; papyrus; parchment; Beresta. A lot later, other artificial information carriers appeared: paper, various types of plastics, photographic, optical and magnetic materials.

Information is entered onto the carrier by changing any physical, mechanical or chemical properties of the working environment.

General information about information and ways to store it

Any natural phenomenon is somehow connected with saving, conversion and transmission of information. It can be discrete or continuous.

In the general sense, the storage medium is a certain physical environment that can be used to register changes and accumulate information.

Requirements for artificial information carriers:

high record density;
the possibility of repeated use;
high speed reading speed;
reliability and durability of data storage;
compactness.

A separate classification is designed for media used in electronic computing complexes. These information are related to such media:

ribbon carriers;
disk carriers (magnetic, optical, magneto-optical);
flash carriers.

This division is conditional and is not exhaustive. With the help of special devices on computer technician, you can work with traditional audio and video cassettes.

Characteristics of individual information carriers

At one time, magnetic information media received the greatest popularity. These data in them are represented as partitions of the magnetic layer, which is applied to the surface of the physical medium. The carrier itself may have a type of ribbon, cards, drum or disc.

The information on the magnetic carrier is grouped into zones with intervals between them: they are necessary for high-quality recording and reading data.

Ribbon type media are used to back up and storing data. They are a magnetic tape of up to 60 GB. Sometimes such carriers have the form of tape cartridges significantly larger volume.

Disk media can be rigid and flexible, replaceable and stationary, magnetic and optical. They are usually the form of disks or floppy disks.

The magnetic disk has a form of plastic or aluminum flat circle, which is covered with a magnetic layer. Locking data at such an object is carried out by magnetic recording. Magnetic discs are portable (replaceable) or unmanable.

Flexible magnetic discs (floppy disks) have a volume of 1.44 MB. They are packed with special plastic enclosures. Otherwise, such information carriers refer to disks. Assigning them - temporary storage of information and data transfer from one computer to another.

A hard magnetic disk is needed for constant data storage that are often used in operation. Such a carrier is a package of their clutched multiple disks concluded in a solid hermetic case. In everyday life, the hard disk is often called "Winchester". The container of such a drive can reach several hundred GB.

A magneto-optical disc is a carrier of information placed in a special plastic envelope called a cartridge. This is a universal and very reliable content of the data. His distinctive feature is a high density of stored information.

Principle of information recording for magnetic carrier

The principle of recording data on the magnetic carrier is based on the use of the properties of ferromagnets: they are able to maintain magnetization after removing the magnetic field acting on them.

The magnetic field creates the corresponding magnetic head. During the record, the binary code takes the form of an electrical signal and is fed to winding the head. When the current flows through the magnetic head, a magnetic field of a certain tension is formed around it. Under the action of such a field in the core, a magnetic flux is formed. His power lines are closed.

The magnetic field interacts with the information carrier and creates a state that is characterized by some magnetic induction. When the current pulse stops, the carrier retains its state of magnetization.

To reproduce the record, use the reading head. The magnetic field of the carrier closes through the core of the head. If the carrier moves, the magnetic flux changes. The playback signal comes to the read head.

One of the important characteristics of the magnetic information carrier is the record density. It is directly dependent on the properties of the magnetic carrier, the type of magnetic head and its design.

What is information carriers

In the theory of information systems, it is customary to divide the carriers of information on origin, form and size. In the simplest case, media are divided into:

local (for example, hard disk personal computer);
alienated (removable disks and discs);
distributed (they can be considered communication lines).

The last form (communication channels) can be considered as media and the medium for its transfer.

In the most general sense, media can be considered different objects in their own form:

paper (books);
plates (photoflaxes, gramophone plates);
films (photo-, film);
audio cassettes;
microfilm (microfilm, microfish);
video tapes;
cDs.

Information is entered onto the carrier by changing any physical, mechanical or chemical properties of the working environment.

General information about information and ways to store it

Any natural phenomenon is somehow connected with saving, conversion and transmission of information. It can be discrete or continuous.

In the general sense, the storage medium is a certain physical environment that can be used to register changes and accumulate information.

Requirements for artificial information carriers:

high record density;
the possibility of repeated use;
high speed reading speed;
reliability and durability of data storage;
compactness.

A separate classification is designed for media used in electronic computing complexes. These information are related to such media:

ribbon carriers;
disk carriers (magnetic, optical, magneto-optical);
flash carriers.

This division is conditional and is not exhaustive. With the help of special devices on computer technician, you can work with traditional audio and video cassettes.

Characteristics of individual information carriers

The information on the magnetic carrier is grouped into zones with intervals between them: they are necessary for high-quality recording and reading data.

Ribbon type media are used to back up and storing data. They are a magnetic tape of up to 60 GB. Sometimes such carriers have the form of tape cartridges significantly larger volume.

Disk media can be rigid and flexible, replaceable and stationary, magnetic and optical. They are usually the form of disks or floppy disks.

Principle of information recording for magnetic carrier

Man always sought not only to learn as much as possible about the world around as possible, but also to transfer all the accumulated information to future generations. In this article, we will consider, although briefly, the development of methods for storing and transmitting information, the evolution of information carriers, ranging from the stone wall in the cave and ending with the latest developments in the field of high technologies.

Deadian antiquity deep ...

Soon, with the advent of the first civilizations, pictography is converted to the hieroglyphic and clig. In the new sign system, abstract concepts, calculus, and others have already appeared. And the sizes itself became less.

Media information has also changed: now the stone walls have become man-made, the stone carving has become more skillful. Compact media also appeared: Papiral sheets in Egypt and clay plates in the interfluve.

The closer to our days, the cheaper, the carriers of the information became more compact, the amount of information increased by order, the language sign system was becoming easier.

From papyrus, humanity passed to the parchment, from parchment - to paper. From the hieroglyphic to the alphabetic letter (even today's hieroglyphic languages \u200b\u200b- Chinese, Japanese, Korean - are based on a standard alphabetical set).

So for several paragraphs, we gave up the past language and carriers of information and, almost, closely approached the main topic.

Evolution of media information in the XX-XXI centuries

Perfocards and punctants

With the development of mechanical engineering and automation of production, it was necessary to program the machines and machines - the task of a sequential set of operations for the rationalization of production. For this, a binary language was created (0/1 - off / incl), and the first carrier of information on the binary language was the punch. The leaf of thick paper was divided into a certain number of cells, one of them made their way, others remained integer. The standard championship carried information in 80 characters.

Later on the same principle of work began to be used perflector - a roll of paper or nitrocellulose ribbon with penetrated holes. Plus, the punctants were relatively high reading speed (up to 1500 b / s), but the low strength of the tape and the impossibility of manual information editing (for example, the punch could be pulled out from the deck and manually trigger the necessary bits).

Magnetic tape

Magnetic came to replace paper carriers. At first, it was a specially magnetized wire (such a carrier and is now used in black boxes of aircraft), then it changed its flexible magnetic tape, which was wounded in reels or compact cassettes. The principle of recording is similar to perforation. The magnetic tape is divided into a width into several independent tracks; Passing through the magnetic recording head, the required area of \u200b\u200bthe tape is magnetized (in analogous to the punched portion), subsequently the magnetized portion will be read by computing technique as 1, not magnetized - like 0.

Flexible magnetic discs

Flexible magnetic disk was invented after the magnetic ribbon - a circle of dense flexible plastic with a magnetic layer applied to the surface. The first flexible discs were an eighty-one, later we had to change the usual 5.25-inch and 3.5-inch. The latter lasted in the market media market until the mid-2000s.

Drives by hard magnetic disks

Parallel to flexible magnetic media developed media on rigid magnetic discs (HDD, hard disk, HDD). The first HDD working model was created in 1956 by IBM (model IBM 350). The IBM 350 volume was 3.5 MB, which in the time there were quite a lot. In size, the first HDD was like a large refrigerator and weighed a little less than a ton.

In the thirty years, the size of the hard disk managed to reduce to the 5.25-inch format (the size of the optical drive), after another ten years the hard drives became the usual 3,5-inch format.

The volume of 1 GB was overcome in the mid-1990s, and in 2005 the maximum amount for the longitudinal recording was 500 GB. In 2006, the first hard disk was released with a perpendicular method of recording a volume of 500 GB. In 2007, it was traced in 1 TB (the model was released by Hitachi). At the moment, the largest volume of the commercial model HDD is 3 TB.

Flash memory is a variety of semiconductor technology of electrically reprogrammed memory (EEPROM). Due to the compactness, cheapness, mechanical strength, large volume, speed and low power consumption, flash memory is widely used in digital portable devices and media.

Distinguish two basic types of flash memory: NOR. and Nand..

NOR memory is used as non-volatile memory of a small volume that requires rapid access without hardware failures (microprocessor cache, POST and BIOS chips).

Nand memory is used in most electronic devices as the main information carrier (cell phones, televisions, media players, game consoles, photo frames, navigators, network routers, access points, etc.). Also, Nand memory is used in SSD drives, an alternative to hard magnetic discs, and as cache in hybrid hard drives. You should also not forget about flash cards of all form factors and types of connection.

The most weighty minus flash memory is a limited number of recording cycles on the media. This is due to the technology of reprogrammed memory.

Optical disks

These carriers are polycarbonate discs with a special metal coating from themselves. Recording and subsequent reading is carried out using a special laser. During the recording on a metal coating, the laser makes special holes (pita), which, upon subsequent reading, the laser drive will be read as "1".

All development of optical media can be divided into four parts:

First generation: Laser discs, CDs, magneto-optical discs. The main feature is relatively expensive discs of small volume, the drives have great power consumption (directly related to the recording and reading technology). CDs are slightly embarrassed from this definition (apparently, therefore they occupied the dominant position until the second generation of optical disks appear).

Second generation: DVD, Minidisc, Digital Multilayer Disk, Dataplay, Fluorescent Multilayer Disc, Gd-Rom, Universal Media Disc. What distinguishes the second generation of optical disks from the first? First of all, the high density of the information recording (6-10 times). In addition to DVD, they mainly have specialized use (MD - for audio recordings, UMD - for Sony PlayStation consoles). In addition to DVD, all other formats require expensive equipment for recording and reading information (especially, DMD and FMD, which use multilayer and multidimensional storage technology).

Third generation: Blu-ray Disc, HD DVD, Forward Versatile Disc, Ultra Density Optical, Professional Disc For Data, Versatile Multilayer Disc. These optical discs are required in high-definition video storage. The main feature is to use blue \u003d purple laser for recording and reading information in the place of red (except VMD). This allows you to further increase the record density (6-10 times compared with the second generation).

As in any evolution, in the development of optical disks there is a basic branch of development and side branches. The types of optical disks that have received the most common and largest commercial success are the main branches: CDs, DVD, Blu-Ray. The remaining types of optical disks either went into a dead end in their development, or have specialized applications.

Fourth Generation (Nearest Future): Holographic Versatile Disc. The main revolutionary technology in the development of optical information carriers is the technology of holographic recording, which allows to increase the record density to an optical disc of about 60-80 times. The first holographic disks were represented in 2006, and the technological standard itself was finally approved in 2007. But WHO is still there. In 2010, it was announced that the plank of the volume of carrier in 515 GB was overcome, but this model of the holographic disk was not allowed into production.

1) Paper Media Information.

One of the most common media is paper. In school, we record information in the notebook, theoretical material is studying on textbooks, when developing a report, an abstract or other communication, we find the necessary information in other sources (books, encyclopedias, dictionaries, etc.), which in its own

the queue is paper media information

The first computing machines worked on perfocards. (Fig. 6, Fig.7)

The magnetic tape turned out to be quite reliable, durable and accessible to each carrier of information.

In the first computer (electronic computing machines), the information was stored on magnetic tapes and magnetic disks (slide 17-1rn computers)

(The explanation of the teacher is accompanied by a demonstration of magnetic disks.

On each desk, one floppy disk is heard for "Research" I student it)

In modern computers, the following magnetic media are used as a carrier:

1) diskette(To which data can be placed 3000 perfocars).

2) hard magnetic disk or winchester (stores 100,000 or more diskettes). Inside the rigid metal case there are several dozen magnetic disks placed on one axis (Fig.12). Recording or reading information is provided by several magnetic heads. In order to save information and performance, hard magnetic discs must be protected from

shocks and sharp changes in the provisions of the system unit (it is impossible

Tilt and turn over in the process).

3) stremmers (Streamart cartridges) - devices that provide recording or reading audio information (Fig. 13). Inside this media is a magnetic tape.

Laser discs are made of plastic, top with a thin layer of metal and transparent varnish that protect against minor scratches or contamination. Recording or reading information in the CD drive is carried out using the Laser Light. When recording a laser beam, microscopic recesses on the disk surface, thereby encoding the information (when read-out the holder, it is reflected from the surface of the rotating disk). Such discs should be protected from dust and scratches.

Distinguish CD and DVDs.

Questions: - What information can be recorded on CD and DVDs?(DVD is called digital video, therefore it can be written video and audio information on it, you can write textual, graphical, sound information on the CD disc).

By way of recording, laser disks are divided into the following types:

· CD- ROM, DVD- ROM- Designed only to read. Write or remove information from such a disk. Such discs include training, game programs, electronic textbooks, etc.

· CD- R., DVD- R.-Grive information to the disk can only once. After recording, delete the data cannot be.

· CD- RW, DVD- RW-write information to such a disc several times.

Web carrier that. Regeneration of RAM. Storage drives on hard magnetic disks

external HDs

Optical disks

Flashki

HDD boxes

Remote servers

Tip 2: Views of information media, their classification and characteristics

From the history of the development of information carriers

What is information carriers

General information about information and ways to store it

Characteristics of individual information carriers

Principle of information recording for magnetic carrier

What is information carriers

General information about information and ways to store it

Characteristics of individual information carriers

Principle of information recording for magnetic carrier

Last

It is necessary to know