Which are recorded on a specific medium. Review of modern electronic storage media

There are so many concepts in the Russian language that it is sometimes difficult to distinguish between two very similar, but still different definitions. But there are terms that do not carry additional meanings, but have a clear and understandable interpretation. For example, the concept of “electronic storage medium”. This is the definition of a tangible medium that records, stores and reproduces data that is processed thanks to computer technology.

Where did it all start?

The more general meaning of this term is “information carrier” or “information carrier”. It defines a material object or environment that is used by a person. Moreover, such an item stores data for a long time without using additional equipment.

If a source of energy is needed to store information on electronic media, then a simple data carrier can be stone, wood, paper, metal and other materials.

Any object that displays data printed on it can be called an information carrier. It is believed that information media are needed for recording, storing, reading, and transmitting materials.

Peculiarities

It is not difficult to guess that an electronic storage medium is a type of information storage medium. It also has its own classification, which, although not officially established, is used by many specialists.

For example, electronic media may be write-once or write-once. Here we mean devices:

• optical;
• semiconductor;
• magnetic.

Each of these mechanisms has several types of equipment.

Electronic storage media has, first of all, a number of advantages over paper versions. First, thanks to technology, the amount of data archived can be virtually unlimited. Secondly, the collection and presentation of relevant information is ergonomic and fast. Thirdly, digital data is presented in a convenient form.

But electronic media also has its drawbacks. For example, this includes the unreliability of equipment, in some cases the size of the device, dependence on electricity, as well as the requirements for the constant availability of a device that could read files from such a digital drive.

Type: optical discs

An electronic storage medium is a device that can be optical, semiconductor, or magnetic. This is the only classification of such equipment.

In turn, optical devices are also divided into types. This includes laser disc, CD, mini-disc, Blu-ray, HD-DVD and so on. The optical disk is so named due to the technology for reading information. Reading from the disk occurs using optical radiation.

The idea of ​​this electronic medium originated a long time ago. The scientists who developed the technology were awarded the Nobel Prize. The method of reproducing information from an optical disc appeared back in 1958.

Now optical electronic media has 4 generations. The first generation had: laserdisc, compact disc and minidisc. In the second generation, DVDs and CD-ROMs became popular. In the third generation, Blu-ray and HD-DVD stood out. In the fourth generation, Holographic Versatile Disc and SuperRens Disc are actively developing.

Semiconductor media

The next type of electronic storage medium is semiconductor. This includes flash drives and SSD drives.

Flash memory is the most popular electronic storage medium that uses semiconductor technology and programmable memory. It is in demand due to its small size, low price, mechanical strength, acceptable volume, speed of operation and low energy consumption.

The disadvantages of this option are the limited service life and dependence on electrostatic discharge. People first started talking about a flash drive in 1984.

An SSD is a semiconductor electronic storage device, also called a solid state drive. It replaced the hard drive, although at the moment it has not completely replaced it, but has only become an addition to home systems. Unlike a hard drive, a solid-state drive is based on memory chips.

The main advantages of such a carrier are its compact size, high speed, and wear resistance. But at the same time it has a high cost.

Magnetic disks

And the last type of electronic media are magnetic devices. These include magnetic tapes, floppy disks and hard drives. Since the first and second equipment are not currently in use, we will talk about the railway.

A hard disk is a random access device based on magnetic recording technology. At the moment, it is the main storage device of most modern computer systems.

Its main difference from the previous type, floppy disk, is that recording is carried out on aluminum or glass plates, which are covered with a layer of ferromagnetic material.

Other options

Despite the fact that, when talking about electronic media, we often think of devices connected to a computer, this does not mean that this concept is applied only in computer technology.

The spread of electronic media is associated with its ease of use, high speed of writing and reading. Therefore, this equipment is replacing paper media.

Documentation

What is a passport with an electronic storage medium? At first, this question may drive a person into a dead end. But if you think about it carefully, you will remember such a concept as a “biometric passport”.

This is a state document that certifies the identity and citizenship of the traveler at the time of his move abroad and stay in another country. Essentially, we have the same passport, but with some nuances.

The difference between a biometric document and a traditional passport is that the first one carries a specially mounted microcircuit that stores the owner’s photo card and his personal data.

Thanks to a small microcircuit, you can obtain the last name, first name and patronymic of the document owner, his date of birth, passport number, time of issue and end of the validity period. According to the model, the microcircuit should contain a person’s biometric data. This includes a pattern of the iris or a fingerprint.

Introduction of the document: advantages and disadvantages

Despite the fact that the biometric passport has long been introduced by many states, some citizens have a negative attitude towards it. But this document has both advantages and disadvantages.

The advantages include the fact that passing the border checkpoint now does not take much time. If in such places there is special equipment that can read a microchip, then crossing the border becomes safe and fast.

But not all citizens like a biometric passport. Many believe that the introduction of such a document is a manifestation of total control, behind which is the US government.

Criminal case

The development of electronic storage media has affected many areas. This also includes a criminal case. In 2012, the term electronic storage medium was introduced into the Criminal Procedure Code of the Russian Federation. Thus, such devices could become material evidence.

Electronic storage media have become an important detail in the investigation of a criminal case, subject to certain conditions. For example, data from the media must be directly relevant to the investigation. In addition, they must be transmitted by a reliable source that can be verified. The data must be in a special form, for example, represented by video recordings, photographs, screenshots, and so on. When seizing digital information, you must comply with established laws.

During the investigation of a criminal case, it is necessary to keep records of electronic storage media. In this case, a log is created in which all devices are registered. Each one is assigned an identification number.

The importance of electronic media in criminal investigation is a controversial issue to this day. Legislatively, such devices are not classified as any source of evidence. This is where disagreements can arise.

conclusions

Electronic storage media for modern people are a real godsend. With the development of technology, the volume of archives that store data is becoming larger. Every year new opportunities for transmitting and reading information appear.

(electromagnetic radiation), etc., etc.

An information carrier can be any object from which it is possible (but not necessary) to read existing (recorded) information.

Often the information carrier itself is placed in a protective shell, which increases its safety and, accordingly, the reliability of storage (for example: paper sheets - in the cover, a memory chip - in plastic (smart card), magnetic tape - in the case, etc. ).

Information media in everyday life, science (libraries), technology (say, for communication needs), public life (mass media) are used for:

• records
• storage
• reading
• transmission (distribution)
• creating works of computer art

In general, the boundaries between these types of media are quite vague and may vary depending on the situation and external conditions. Basic materials paper (punched tape, punched card, sheets); plastic (bar code, optical discs); magnetic materials (magnetic tapes and disks); Also previously widespread were: baked clay, stone, bone, wood, parchment, birch bark, papyrus, wax, fabric, etc. To make changes in the structure of the carrier material, various types of influence are used: thermal (burning); Electronic media Electronic media include media for single or multiple recording (usually digital) electrically: CD-ROM, DVD-ROM, semiconductor (flash memory, etc.), floppy disks. They have a significant advantage over paper (sheets, newspapers, magazines) in terms of volume and unit cost. For storing and providing operational (not long-term storage) information, they have an overwhelming advantage; there are also significant opportunities for providing information in a form convenient for the consumer (formatting, sorting). Disadvantage - small screen size (or significant weight) and fragility of reading devices, dependence on. Currently, electronic media are actively replacing paper media in all sectors of life, which leads to significant wood savings. Their disadvantage is that to read AND for each type and format of media, you need a corresponding reading device. Storage devices The disadvantage of this medium was that over time it darkened and broke. An additional disadvantage was that the Egyptians introduced a ban on the export of papyrus abroad. Asia The disadvantages of storage media (clay, papyrus, wax) stimulated the search for new media. This time the principle “everything new is well-forgotten old” worked: in Persia, from ancient times, defter was used for writing - dried animal skins (in Turkish and related languages, the word “defter” still means a notebook), which the Greeks remembered. Europe On the territory of Europe, highly developed peoples (Greeks and Romans) groped for their own recording methods. Many different media are used: lead sheets, bone plates, etc. Since the 7th century BC. e. recording is made with a sharp stick - a stylus (as in clay) on wooden tablets covered with a layer of pliable wax (so-called wax tablets). Erasing information (another advantage of this medium) was done with the opposite blunt end of the stylus. Such boards were fastened together in groups of four (hence the word “notebook”, since ancient Greek. τετράς translated from Greek - four). However, inscriptions on wax are short-lived, and the problem of preserving records was very pressing. America In the 11th-16th centuries, the indigenous peoples of South America came up with the knotted letter “quipu” (quipu translated from the language of the Quechua Indians - knot). “Messages” were made from ropes (rows of laces were tied to them). The type, number of knots, color and number of threads, their arrangement and weave constituted a “coding” (“alphabet”) of the quipu. The Indian tribes of North America encoded their messages with small shells strung on cords. This type of writing was called "wampum" - from the Indian word wampam (short for wampumpeag) - white beads. The interweaving of cords formed a strip, which was usually worn as a belt. Entire messages could be composed by combining colored shells and drawings on them. Ancient Rus' Birch bark (the top layer of birch bark) was used as a carrier. The letters on it were cut out with a writing tool (a bone or metal stick). By the end of the 16th century, Rus' had its own paper (the word “paper” most likely came into Russian from Italian, bambagia - cotton). Middle Ages In the ancient world and the Middle Ages, wax tablets were used as notebooks, for household notes, and for teaching children to write. New time Modernity Nowadays people use computers to process and store information. see also Bearer of the name Bearer of the surname Nucleic acids (DNA, RNA) Links Notes Personal computer components

Main types of storage media

Information carriers: living beings, inanimate objects and structures, signal, sign, symbol. Any object carries some information about itself and the objects around it, that is, it is a carrier of information.

There is an idea that information carriers have material, material and relational properties. The former imply the properties of the substances from which the carriers are made; the second are the properties of processes and fields with the help of which media exist, and the third are elemental (species) properties that make it possible to distinguish some media from others, for example, by shape and size. Physical media are divided into: local (computer), alienable (portable disks and floppy disks) and distributed (communication lines). Regarding the latter, there is no clear opinion because communication channels can be represented as data carriers, but at the same time they are the medium for their transmission.

Usually under information carriers imply the generally accepted name of their form, that is: paper (book, brochure, etc.), record (gramophone record, photographic plate), film (photo, film, x-ray film), audio cassette, floppy disk, microform (photographic film, microfilm, microfiche), video cassette, CD ( CD, DVD) etc.

Such media have long been known: stone (rock paintings, stone slabs), clay tablets, parchment, papyrus, birch bark and others. Then the following media appeared: paper, plastic, photographic materials, magnetic and optical materials, and more.

Nowadays they are divided into: traditional and machine-readable. Under traditional We will understand the following information media: paper, canvas, plastic (gramophone record), magnetic tape (audio and video cassette), photographic materials (photographic film, photographic plate, photographic print, micromedia), etc. TO machine readable media We include: floppy disks (floppy magnetic disks), hard magnetic and compact (optical, magneto-optical and other) disks, flash cards and other storage media intended for use in computer devices, complexes, systems and networks. Information is recorded on a medium by changing the physical, chemical or mechanical properties of the storage medium.

A variant of the classification of storage media used in computer technology is presented in Fig. 5-1.

Rice. 5-1. Classification of storage media used

in computer technology

Note that this division is conditional. For example, using special devices on computers, you can work with ordinary audio and video cassettes, and devices for recording and long-term storage of data (streamers) use well-known magnetic media (magnetic tapes), etc. Therefore, we will refer to traditional media as data of an analog nature, and as machine-readable, that is, used in computers, as digital data or electronic information resources (EIR).

Let's give them a brief description.

Magneto-optical disk (MO) disk is enclosed in a plastic envelope (cartridge). MO-disk is a universal, fast, highly reliable device for transferring and storing information. Characterized by high density of information recording. Disks with a diameter of 3.5" have a capacity of 128 MB - 1.3 GB, and with a diameter of 5.25" - from 2.3 to 9.1 GB. Disk rotation speed – 2000 rpm.

Introduction page 3

Modern material carriers of documented information, their classification and characteristics

I. Modern material media p. 5

II. Classification of modern material media p. 6

III. Characteristics of modern material media

1. Magnetic media page 9

2. Plastic cards page 12

3. Optical media p. 13

4. Flash storage media p. 17

5. 3D image media p. 19

Conclusion page 23

References page 26

Introduction

The concept of document is central, fundamental in the conceptual system of document management. This concept is widely used in all spheres of public activity. Almost every branch of knowledge has one or several versions for its understanding in accordance with the specifics of those objects that are given the status of a document.

The concept of document acts as a generic concept for specific types: published, unpublished, film, sound, photographic document, etc. from this point of view, the following types of document are: booklet, drawing, map, film, magnetic tape, magnetic and optical disk.

Let us recall once again the definition of a document: information fixed on a material medium in a stable symbolic form in a man-made way for its transmission in space and time. From the definition it follows that the document does not exist in finished form, it needs to be created, i.e. fix in a stable form. The process of fixing (fixing) information on a tangible medium is called documentation.

In the process of documentation, social information is transformed from one symbolic form to another, i.e. coding of information, without which it is impossible to implement the basic functions of a document - the functions of securing and transmitting information in space and time.

The informatization of society, the rapid development of micrography, computer technology and its penetration into all spheres of activity determined the appearance of documents on the latest storage media. The presence of a general concept of a document does not exclude the possibility of the existence of more private, highly specialized interpretations of it in relation to various spheres of social activity and scientific disciplines: source study, record keeping, diplomacy, computer science, legal science.

Among these new media, the group of “Modern media for documented information” stands out, which are currently in use, replacing older media with increasing popularity. For example, it seems that not so long ago a very common storage medium - a flexible magnetic disk or floppy disk is practically not used, it was replaced by optical disks and media based on flash memory, the same phenomenon is happening in audio and video technology, audio and video cassettes have been replaced optical disks.

This topic “Modern material storage media, their classification and characteristics” also concerns document and communication activities, as it examines the means that simplify the exchange of information.

I believe that the topic of my course work is relevant at the present time, since knowledge and ability to use modern media allows us to keep up with the times and speed up the process of creating and transmitting information in space and time, as well as improve the conditions for storing documented information.

Modern material carriers of documented information, their classification and characteristics

I. Modern material media

The informatization of society, the rapid development of computer technology and its penetration into all spheres of human activity determined the appearance of documents in modern, non-traditional, i.e. non-paper media.

The concepts of “modern” and “non-traditional” document are largely arbitrary and serve to name a group of documents that, unlike traditional ones, i.e. paper ones, as a rule, require modern technical means to reproduce information. All this is connected with the advent of electronic computers - computers, which are complexes of technical means designed to automatically convert information, used to record and reproduce both text, graphic, audio and video information.

The emergence of modern media is also due to the fact that over half a century of its existence there have already been five generations of computers, and from generation to generation their productivity and storage capacity have increased by an order of magnitude or more. And also new, more advanced peripheral devices appeared - printers, scanners, copiers, and now multifunctional devices (MFPs) are increasingly used, which facilitate the work of office workers, allowing them to obtain a hard copy of a document not only from the computer’s memory, but from modern media .

From my point of view, modern media for documented information include: magnetic cards, magnetic hard drives, optical discs, holograms, flash memory-based media. This may not be the correct judgment, but these media are actively used at present. They replaced the well-known audio, video cassettes, microforms, floppy disks or floppy disks. They can be called outdated. The same thing will happen with modern media, because they are modern at the moment. In ten years, modern media will be replaced by even more modern media, since humanity does not stand in one place, but is progressing and developing at a rapid pace. And in ten years, the modern material carriers of documented information discussed in this work will be called obsolete.

II . Classification of modern material media

A document is a dual unity of information and a material medium. Therefore, important features (“strong differences”) that can be used as the basis for classification are the structural features and shape of the material on which information is recorded. In particular, according to this criterion, the entire variety of documents contained on modern material media can be represented as a class:

· documents on an artificial material basis (on polymer materials).

In turn, documents on an artificial material basis can be classified as multilayer, in which there are at least two layers - a special working layer and a substrate (magnetic media, optical disks, etc.). In this case, the base substrate can be of any kind - paper, metal, glass, ceramic, wood, fabric, film or plastic plate. From one to several (sometimes up to 6-8) layers are applied to the base. As a result, the material carrier sometimes appears in the form of a complex polymer system.

There are also energy carriers.

According to the form of the material storage medium, documents can be:

· card (plastic cards);

· disk (disc, compact disc, CD-ROM, video disc). The information is placed on concentric tracks – optical discs.

Depending on the possibility of transporting material media, documents can be divided into:

· stationary (hard magnetic disk in a computer);

· portable (optical disks, flash memory-based media).

Depending on the method of documentation, documents on modern storage media can be divided into:

· magnetic (magnetic hard drives, magnetic cards);

· optical (laser) – documents containing information recorded using a laser-optical head (optical, laser discs);

· holographic – created using a laser beam and a photo-recording layer of a material carrier (hologram).

· documents on computer media – electronic documents created using media and recording methods that ensure the processing of its information by an electronic computer.

Documents on modern tangible media, as a rule, cannot be directly perceived or read. Information is stored on computer media, and some documents are created and used directly in machine-readable form.

In terms of intended for perception, the documents in question are classified as machine readable. These are documents designed to automatically reproduce the information contained in them. The content of such documents is fully or partially expressed by signs (matrix arrangement of characters, numbers, etc.), adapted for automatic reading. Information is recorded on magnetic tapes, cards, disks and similar media.

Documents on modern storage media belong to the class of technically encoded ones, containing a recording that can be reproduced only with the help of technical means, including sound reproducing, video reproducing equipment or a computer.

Based on the nature of the connection between documents and technological processes in automated systems, the following are distinguished:

· a machine-oriented document designed to record the reading of part of the information contained in it using computer technology (filled out special forms, forms, questionnaires, etc.);

· machine-readable document, suitable for automatic reading of the information contained in it using a scanner (text, graphic);

· a document on a machine-readable medium, created by computer technology, recorded on a machine-readable medium: hard magnetic disk, optical disk, flash memory-based medium - and executed in the prescribed manner;

· a document-machineogram (printout), created on paper using computer technology and executed in the prescribed manner;

· a document on the display screen, created by computer technology, reflected on the display screen (monitor) and executed in the prescribed manner;

· an electronic document containing a set of information in the memory of a computer, intended for human perception using appropriate software and hardware.

III . Characteristics of modern material media

1. Magnetic media

Of all the carriers of magnetic documents, I would like to highlight the magnetic disk - an information carrier in the form of a disk with a ferromagnetic coating for recording. Magnetic disks are divided into hard disks (hard drives) and floppy disks (floppy disks).

From this group, in my work I will consider only hard drives, since floppy disks, which I call obsolete storage media, have been practically replaced by optical disks and flash memory-based media.

Hard disks

Hard magnetic disks, called hard drives, are designed for permanent storage of information used when working with a personal computer and are installed inside it.

Hard drives are significantly superior to floppy disks. They have the best characteristics of capacity, reliability and speed of access to information. Therefore, their use ensures high-speed characteristics of the dialogue between the user and the programs being implemented, expands the system capabilities for using databases, organizing multitasking modes of operation, and provides effective support for the virtual memory mechanism. However, the cost of hard drives is much higher than the cost of floppy disks.

The hard drive is mounted on a spindle axis driven by a special motor. It contains from one to ten disks (platters). The engine speed for conventional models can be 3600, 4500, 5400, 7200, 10000 or even 12000 rpm. The disks themselves are ceramic or aluminum plates processed with high precision, on which a magnetic layer is applied.

The most important part of a hard drive is the read-write head. As a rule, they are located on a special positioner (head actuator). To move the positioner, predominantly linear motors (such as voice coils) are used. Several types of heads are used in hard drives: monolithic, composite, thin-film, magnetoresistive (MR, Magneto-Resistive), as well as heads with enhanced magnetoresistive effect (GMR, Giant Magneto-Resistive). The magnetoresistive head, developed by IBM in the early 1990s, is a combination of two heads: a thin-film write head and a magnetoresistive read head. Such heads make it possible to increase the recording density by almost one and a half times. The GMR head can further increase the recording density.

Inside any hard drive there is always an electronic board that deciphers the commands of the hard drive controller, stabilizes the engine rotation speed, generates signals for the write heads and amplifies them from the read heads.

There are two types of hard magnetic disks.

Hard disk (hard disk) is a built-in storage device (disk drive) on a hard magnetic disk, a package of magnetic disks fixed one above the other, the removal of which during operation of electronic computers is impossible.

A removable hard disk is a package of magnetic disks enclosed in a protective shell, which during operation of electronic computers can be removed from the drive on a removable hard disk and replaced with another. The use of these disks provides a virtually unlimited amount of external computer memory.

During the so-called low-level formatting procedure, information is written to the hard drive that determines the layout of the hard drive into cylinders and sectors. The format structure includes various service information: synchronization bytes, identification headers, parity bytes. In modern hard drives, such information is recorded once during the manufacture of the hard drive. Damage to this information due to independent low-level formatting can lead to complete inoperability of the disk and the need to restore this information to factory conditions.

The capacity of a hard drive is measured in megabytes. By the end of the 1990s, the average capacity of hard drives for desktop systems reached 15 gigabytes, and servers and workstations with a SCSI interface use hard drives with a capacity of over 50 gigabytes. Most modern personal computers use hard drives with a capacity of 40 gigabytes.

One of the main characteristics of a hard drive is the average time during which the hard drive finds the necessary information. This time is usually the sum of the time required to position the heads on the desired track and wait for the required sector. Modern hard drives provide access to information in 8-10 ms.

Another characteristic of a hard drive is the read and write speed, but it depends not only on the disk itself, but also on its controller, bus, and processor speed. For standard modern hard drives this speed is 15-17 MB/s.

2. Plastic cards

Plastic cards are a device for magnetic storage and data management.

Plastic cards consist of three layers6 of a polyester base, on which a thin working layer is applied, and a protective layer. Polyvinyl chloride is usually used as a base, which is easy to process and resistant to temperature, chemical and mechanical influences. However, in a number of cases, the basis for magnetic cards is pseudoplastic - thick paper or cardboard with double-sided lamination.

The working layer (ferromagnetic powder) is applied to the plastic using hot stamping in the form of separate narrow strips. Based on their physical properties and scope of application, magnetic strips are divided into two types: high-ercivity and low-ercivity. High-ercivity stripes are black. They are resistant to magnetic fields. To record them, higher energy is needed. Used as credit cards, driver's licenses, i.e. in cases where increased wear resistance and security are required. Low-ercivity magnetic stripes are brown in color. They are less secure, but they are easier and faster to record. They are used on cards with a limited validity period, in particular for travel in the metro.

It should be noted that, in addition to magnetic, there are other ways to record information on a plastic card: graphic recording, embossing (mechanical extrusion), barcoding, laser recording. In particular, electronic chips have recently begun to be increasingly used in plastic cards instead of magnetic stripes. Such cards, in contrast to simple magnetic ones, began to be called intelligent or smart cards (from the English smart - smart). The microprocessor built into them allows you to store a significant amount of information, makes it possible to make the necessary calculations in the system of banking and trade payments, thus turning plastic cards into multifunctional storage media.

According to the method of access to the microprocessor (interface), smart cards can be:

· with a contact interface (i.e., when performing a transaction, the card is inserted into the electronic terminal;

· with a dual interface (can operate both contact and contactless, i.e. data exchange between the card and external devices can be carried out via a radio channel).

The protective layer of magnetic plastic cards consists of a transparent polyester film. It is designed to protect the working layer from wear. Sometimes coatings are used to protect against counterfeiting and copying. The protective layer provides up to two tens of thousands of write and read cycles.

The sizes of plastic cards are standardized. In accordance with the international standard ISO-7810, their length is 85.595 mm, width - 53.975 mm, thickness - 3.18 mm.

The scope of application of plastic and pseudo-plastic magnetic cards is quite extensive. In addition to banking systems, they are used as a compact information carrier, identifier for automated accounting and control systems, identification, pass, telephone and Internet cards, and transport tickets.

3. Optical media

The continuous scientific and technical search for material carriers of documented information with high durability, large information capacity with minimal physical dimensions of the medium has led to the emergence of optical disks, which have recently become widespread. They are plastic or aluminum discs designed to record or reproduce sound, images, alphanumeric and other information using a laser beam.

Standard CDs are 120 mm (4.75 in) in diameter, 1.2 mm (0.05 in) thick, and have a 15 mm (0.6 in) center hole. They have a rigid, very durable transparent, usually plastic (polycarbonate) base 1mm thick. However, it is possible to use other materials as a base, for example, an optical medium with a cardboard base.

The working layer of optical disks was initially made in the form of thin films of low-melting materials (tellurium) or alloys (tellurium-selenium, tellurium-carbon, tellurium-lead, etc.), and later - mainly based on organic dyes. Information on a CD is recorded on the working layer in the form of a spiral track using a laser beam, which acts as a signal converter. The path goes from the center of the disk to its periphery.

As the disk rotates, the laser beam follows a track whose width is close to 1 micron, and the distance between two adjacent tracks is up to 1.6 microns. The marks (pits) formed on the disk by a laser beam have a depth of about five billionths of an inch and an area of ​​1-3 microns 2. The internal recording diameter is 50 mm, the external one is 116 mm. The total length of the entire spiral path on the disk is about 5 km. There are 625 tracks for every mm of disk radius. In total, the disk contains 20 thousand turns of a spiral track.

To ensure good reflection of the laser beam, the so-called “mirror” coating of the disks with aluminum (in regular disks) or silver (in recordable and rewritable disks) is used. A thin protective layer of polycarbonate or a special varnish with high mechanical strength is applied to the metal coating, on top of which drawings and inscriptions are placed. It must be borne in mind that it is this painted side of the disk that is more vulnerable than the opposite side, from which information is read through the entire thickness of the disk.

The manufacturing technology of optical discs is quite complex. First, a glass matrix is ​​created - the basis of the disk. For this purpose, plastic (polycarbonate) is heated to 350 degrees, then it is “injected into the mold, instantly cooled and automatically fed to the next technological operation. A photorecording layer is applied to the original glass disc. In this layer, a Pit system is formed by the laser recording system, i.e. a primary “master disk” is created. Then, mass replication and creation of copy disks are carried out using the “master disk” by injection molding.

The information capacity of disks is usually less than 650 MB. Several hundred thousand pages of typewritten text can be recorded on one disk. For comparison: the entire book collection of the Russian State Library, if transferred to CDs, can fit in an ordinary three-room apartment. Meanwhile, optical disks with a much larger capacity have already been developed - over 1 GB.

Since recording and playback of information on optical discs are contactless, the possibility of mechanical damage to such discs is virtually eliminated.

It, like a magnetic document, belongs to modern information carriers based on optical methods of recording, reading and playback. Optical documents include optical discs and video discs: compact discs, CD-ROM, DVD.

Scheme of the design of an optical video disk: 1 - outer layer of transparent plastic; 2 - metallized reflective recording track; 3 - hard opaque plastic base.

Information is written and read onto an optical disc using a focused laser beam.

Depending on the ability to be used for recording and reading, optical discs are divided into two types:

1. WORM (Write Once Read Many) – drives designed for recording information and storing it;

2. CD-ROM (Compact Disk Read Only Memory) - drives designed for reading information.

Optical discs can be divided into types:

· An audio CD is a disk with permanent (non-erasable) audio information recorded in binary code;

· CD-ROM is a disk with permanent memory designed for storing and reading significant amounts of information. It contains computer information that is read by a disk drive connected to the PC;

· Video CD – a disk on which text, visual and audio information, as well as computer programs, are digitally recorded;

· DVD disc is a type of new generation of optical discs on which text, video and audio information, as well as computer data, are digitally recorded;

· Magneto-optical disk – disks consisting of various combinations of a floppy magnetic disk, hard drive and optical disk.

4. Flash storage media

One of the most modern and promising carriers of documented information is solid-state flash memory, which is a microcircuit on a silicon chip. This is a special type of non-volatile rewritable semiconductor memory. The name refers to the enormous erasing speed of the flash memory chip.

To store information, flash media does not require additional energy, which is needed only for recording. Moreover, compared to hard drives and CD-ROM media, recording information on flash media requires tens of times less energy, since there is no need to operate mechanical devices, which consume most of the energy. Maintaining an electrical charge in flash memory cells in the absence of electrical power is achieved using the so-called floating gate transistor.

Flash memory-based media can store recorded information for a very long time (from 20 to 100 years). Being packaged in a durable, hard plastic case, flash memory chips can withstand significant mechanical loads (5-10 times higher than the maximum permissible for conventional hard drives). The reliability of this type of media is also due to the fact that they do not contain mechanically moving parts. Unlike magnetic, optical and magneto-optical media, it does not require the use of disk drives using complex precision mechanics. They are also distinguished by silent operation.

In addition, these media are very compact.

Information on flash media can be changed, i.e. rewrite. In addition to media with a single write cycle, there is flash memory with a number of allowable write/erase cycles up to 10,000, as well as from 10,000 to 100,000 cycles. All these types are not fundamentally different from each other.

Despite their miniature size, flash cards have a large memory capacity of many hundreds of MB. They are universal in their application, allowing you to record and store any digital information, including music, video and photographic information.

Flash memory has become one of the main storage media widely used in various digital multimedia devices - laptop computers, printers, digital voice recorders, cell phones, electronic watches, notebooks, televisions, air conditioners, MP3 players, digital photo and video cameras.

Flash cards are one of the most promising types of material carriers of documented information. A new generation of cards has already been developed - Secure Digital, which have cryptographic information protection capabilities and a highly durable housing that significantly reduces the risk of damage to the media by statistical electricity.

Cards with a capacity of 4 GB have been released. They can hold about 4,000 high-resolution photos, or 1,000 songs in MP3 format, or a full DVD movie. Meanwhile, the use of a flash card with a capacity of 8 GB is gaining momentum.

The production of so-called fixed flash drives with a capacity of hundreds of MB has been launched, which are also a device for storing and transporting information.

Thus, the improvement of flash memory technology is moving in the direction of increasing the capacity, reliability, compactness, versatility of media, as well as reducing their cost.

5. Three-dimensional image media

Hologram is a modern medium of three-dimensional image.

It is a document containing an image, the recording and reproduction of which is carried out optically using a laser beam without the use of lenses.

A hologram is created using holography - a method of accurately recording, reproducing and transforming wave fields. It is based on wave interference - a phenomenon observed during the addition of transverse waves (light, sound, etc.) or when waves are amplified at some points of the document and weakened at others, depending on the phase difference of the interfering waves. At the same time as the “signal” wave scattered by the object, a “reference” wave from the same light source is directed onto the photographic plate. The pattern that appears during the interference of these waves, containing information about the object, is recorded on a photosensitive surface (hologram). When a hologram or a section of it is irradiated by a reference wave, a three-dimensional image of the object can be seen.

The peculiarity of holography is the creation of a visual image of an object that has all the characteristics of the original. In this case, a complete illusion of the presence of the object is achieved.

On a hologram, information is recorded and reproduced using a laser. The quality of the image depends on the monochromaticity of the laser radiation and the resolution of the photographic materials used to obtain holograms. If the laser radiation spectrum is wide, then the resulting interference pattern will not be clear and blurry. Therefore, when producing holograms, lasers with a very narrow spectral line of radiation are used. The quality of the holographic image is affected by shooting conditions and the resolution of photographic materials. Externally, the hologram resembles an exposed photographic negative, on which there are no signs of the “photographed” object. However, it is enough to illuminate the hologram with a laser beam and a three-dimensional image appears. Objects are located in the depths of the photographic plate, like a reflection in a mirror.

With the help of holography, it is possible to obtain such three-dimensional images that create a complete illusion of the reality of the observed objects - a visual sensation of volume and color, including all shades of color and angle. In a hologram, the image of an object is so perfect and believable that the observer perceives it as a real object.

A hologram can be flat or three-dimensional. The larger the volume of the hologram (the thickness of the photosensitive film), the better all its properties are realized.

A hologram differs from an ordinary photograph in the same way as a sculpture differs from a painting. In ordinary photography, the image point on the photographic plate corresponds to some point on the object. In holography, each point of an object emits a scattered wave that hits the entire surface of the hologram. As a result, any point of the object corresponds to the entire surface of the hologram: if you disassemble the photographic plate on which the hologram is recorded, any part of it is enough to reconstruct the image of the scattering object in three dimensions. This is reminiscent of a lens breaking. Using any of its fragments you can get an image of an object.

Holography uses the coherence property of a laser beam: the wave surface (wave front) of a certain beam is recorded in the form of interference fringes on a photosensitive material or photographic plate, which is called a hologram. When reading the hologram, the original wavefront is restored. In other words, the laser beam is split into two beams, one of which is projected onto the photographed object, and, reflected from this object, the light hits the photosensitive material; the second beam is directly projected onto the photosensitive material.

Using these two beams, an interference pattern is recorded. When a laser beam is projected onto the manufactured hologram, a three-dimensional image of the photographed object pops up. This process is called recovery. If you examine the hologram through a microscope, you will see a system of alternating light and dark stripes. The interference pattern of real objects is very complex.

A hologram can also be made in another way, thanks to which a three-dimensional image can be seen in ordinary light.

Since a hologram allows you to record an image down to the phase components of a light beam, it can store three-dimensional information about the object being photographed. Currently, this technology is used in bar code readers, optical disc cartridges, and can also be successfully used to convert information in optical computers.

Most of the methods being developed and implemented for holographic registration and processing of information arrays most often take the form of printed documents. A hologram is an optical element that forms an image without the help of external optics, which is the most important advantage. Up to 150 images can be applied to one hologram, and these images do not interfere with each other during their reproduction. It is only necessary to respect the angle at which each image was recorded. The hologram is noise-resistant; damage to some part of it does not lead to the loss of the entire image. Since each point of the object is recorded over almost the entire area of ​​the hologram, scratches, dust, and foreign inclusions in the emulsion cause only minor deterioration of the image and a decrease in its brightness.

A square centimeter of film surface can contain 100 million bits of information. And on a potassium-bromine plate measuring 2.5*2.5*0.2 cm, you can record about 300 thousand images of documentary information, approximately the entire archive of a large library.

The invention of holograms is of great importance. Developing computing technology requires long-term storage devices with large amounts of memory. Electronic memory successfully copes with this work. But holographic memory systems are even more suitable for these purposes. The capacity of holographic memory can be 10 6 – 10 8 bits. Within microseconds, it selects data from memory cells.

Conclusion

Having considered this topic, we can say that with the development of science and technology, new information carriers will appear, more advanced ones, which will displace the outdated information carriers that we use now.

The widespread use of optical disks is associated with a number of their advantages compared to magnetic media, namely: high reliability during storage, a large amount of stored information, recording audio, graphics and alphanumeric information on one disk, search speed, economical means of storing and providing information , they have a good quality/price ratio.

As for hard drives, no computer has yet managed without them. In the development of hard drives, the main trend is clearly visible - a gradual increase in recording density, accompanied by an increase in spindle head rotation speed and a decrease in information access time, and ultimately - an increase in performance. The creation of new technologies is constantly improving this media; it changes its capacity to 80 - 175 GB. In the longer term, a carrier is expected to appear in which individual atoms will play the role of magnetic particles. As a result, its capacity will be billions of times higher than currently existing standards. There is also one advantage: lost information can be recovered using certain programs.

Improvements in flash memory technology are moving towards increasing the capacity, reliability, compactness, versatility of media, as well as reducing their cost.

Holographic digital storage media with a capacity of up to 200 GB are at the development stage. They have the shape of a disk consisting of three layers. A 0.2 mm thick recording (working) layer and a half-millimeter transparent protective layer with a reflective coating are applied to a glass substrate 0.5 mm thick.

The future development of the document is associated with the computerization of the document and communication system, while traditional types of documents will remain in the information society along with non-traditional types of information media, enriching and complementing each other.

Documents, being a mass social product, are characterized by relatively low durability. During their operation in the operational environment and especially during storage, they are subject to numerous negative influences, and the media are not only subject to damage in the external environment, they are subject to technical (in terms of the level of equipment development) and logical (related to the content of information, software and information security standards ) aging.

In connection with these factors, work is actively underway to create compact carriers that work with atoms and molecules. The packing density of elements assembled from atoms is thousands of times greater than in modern microelectronics. As a result, one CD made using this technology can replace thousands of laser discs.

The rapid development of the latest information technologies thus leads to the creation of ever new, more information-intensive, reliable and affordable carriers of documented information.

Future document specialists must be prepared for this psychologically, theoretically and technologically. We need to keep up with the times, since document management is inextricably linked with computer science, where science does not stand in one place.

Someday in Russia a multifunctional medium will be used that will store information about a person, allowing it to be used simultaneously as a document: identifying an individual, carrying bank card information, medical data about diseases, it can be used in transport, libraries, etc. d. All this will be possible only with the development of document science, computer science, and jurisprudence, and it will depend on people whether they are ready for such global changes.

Used Books:

1. GOST Z 51141-98. Record keeping and archiving. Terms and Definitions. M.: Standards Publishing House, 1998.

2. Kushnarenko N.N. Documentation. Textbook. – K.: Zannanya, 2006.

3. Larkov N.S. Documentation. – M.: Vostok-Zapad, 2006.

4. Great Encyclopedia of Cyril and Methodius on DVD. – Ural Electronic Plant LLC, 2007. Persons. VAF No. 77-15

GOST Z 51141-98. Record keeping and archiving. Terms and Definitions. M.: Standards Publishing House, 1998.

Kushnarenko N.N. Documentation. – K.: Zannaya, 2006. – P. 432.

Larkov N.S. Documentation. – M.: Vostok-Zapad, 2006. – P. 174.

Great Encyclopedia of Cyril and Methodius on DVD. – Ural Electronic Plant LLC, 2007. Persons. VAF No. 77-15

Kushnarenko N.N. Documentation. – K.: Zannaya, 2006. – P. 451.

Storage medium-- an item used by a person for long-term storage of information.

Optical discs

Disc-shaped storage media, information from which is read using a laser. Information is stored in the form of pits (pit - pit) and lands (land - earth) on a polycarbonate layer. If the light is focused between the pits (on the landing), then the photodiode registers the maximum signal. If light hits the pit, the photodiode registers a lower light intensity.

First generation

Compact disc(CD)- developed by Sony and Phillips in 1979, used primarily for recording audio files. They have a volume from 650 MB to 900 MB. They are divided into CD-R (Compact Disc Recordable) for one-time recording and CD-RW (Compact Disc ReWritable) for multiple recording. Still very common today.

Second generation

Digital Versatile Disc(DVD)- was announced in 1995. Thanks to the denser structure of the working surface and the ability to apply it to both sides of the disc, it significantly exceeds CDs in volume from (1.46 GB to 17.08 GB). Also divided into DVD-R and DVD-RW, DVD+R and DVD+RW, which are more advanced than the previous two, and DVD-RAM, which allows for a significantly greater number of rewrites than DVD+RW. The most common optical disks at the moment.

Digital Multilayer Disc(DMD)- optical disc developed by D Data Inc. The disk is based on three-dimensional optical data storage technology, that is, the laser reads from several working surfaces simultaneously. DMDs can store between 22 and 32 GB of binary information. DMDs are coated with proprietary chemical compounds that react when a red laser illuminates a specific layer. At this point, a chemical reaction produces a signal that will subsequently be read from the disk. Thanks to this, the drives can potentially hold up to 100 GB of data.

Fluorescent Multilayer Disc(FMD)- an optical media format developed by Constellation 3D that uses fluorescence instead of reflection to store data, allowing operation in accordance with the principles of bulk optical memory and having up to 100 layers. They allow you to store up to 1 TB of storage space the size of a regular CD. The pits on the disk are filled with fluorescent material. When coherent light from a laser is focused on them, they flash, emitting incoherent light waves of different wavelengths. As long as the disk is clean, light is able to pass through many layers unimpeded. Blank discs have the ability to filter laser light (based on wavelengths and coherence) while achieving a higher signal-to-noise ratio than reflection-based discs. This allows you to have many layers.

Third generation

Blu-ray Disc(BD)- an optical disc format used for high-density recording of digital data. The modern version of this disc was introduced in 2006. It got its name (blue ray) from the technology of writing and reading using a short-wavelength blue laser, which made it possible to compress the data on the disk. Can hold from 8 to 50 GB.

High Capacity DVD(HD DVD)- an analogue of the previous disk format with a capacity of up to 30 GB. Not supported since 2008 to avoid a format war.

High Capacity Multi-Value Multi-Tier Disks (HDVMD)- a digital media format on optical discs designed for storing high-definition video and other high-quality multimedia data. One layer of an HD VMD disk can hold up to 5 GB of data, but due to the fact that the disks are multilayer (up to 20 layers), their capacity reaches 100 GB. Unlike the previous two formats, it uses a red laser, which allows them to be read by drives that support CD and DVD discs.

Fourth generation

Holographic Multipurpose Disc(HVD)- a promising optical disc format being developed, which intends to significantly increase the amount of data stored on the disc compared to Blu-Ray and HD DVD. It uses a technology known as holography, which uses two lasers, one red and one green, combined into one parallel beam. The green laser reads data encoded in a grid from a holographic layer close to the surface of the disc, while the red laser is used to read auxiliary signals from a regular CD layer deep inside the disc. Estimated capacity - up to 4 TB.

Hard disks

Hard disk drive- a storage device, the main storage device in most computers. The principle of operation is based on changing the magnetization vectors of domains (a small section of a disk) of a magnetic disk under the influence of alternating current in a coil at the end of the read head. They are widespread due to their very high capacity and operating speed. Many hard drives make noise. Household disks usually store information up to 1 TB. There are also external hard drives that are connected to the computer via a USB port; they do not provide the same speed as internal ones, but they provide the same large capacity. In addition, hybrid hard drives with flash memory elements are being developed.

Media using flash memory technology

Flash memory- a type of semiconductor technology for electrically reprogrammable memory. The operating principle of semiconductor flash memory technology is based on the change and registration of electrical charge in an isolated region (“pocket”) of the semiconductor structure. The advantages of such media are compactness, low cost, mechanical strength, large volume, speed and low power consumption. A serious disadvantage of this technology is the limited service life of the media.

USB flash drive- a storage device invented in 2000. Very popular due to its ease of use and versatility. Can store information without electricity for up to 10 years.

Memory card- a storage device of various types, used for certain devices, such as mobile phones, PDAs, car recorders. The most common standard is microSD.

 

It might be useful to read:

• Review of modern electronic storage media;
• Data backup programs;
• How to set up a Windows 8 MTS modem correctly;
• How to check Internet ping?;
• What is a chipset, north and south bridge, types of chipsets;
• MTS abroad: opportunities, services and prices for calls, SMS and Internet;
• Smoothing mouse zoom changes gta 5;
• Installing a cache for an Android game;