What was the main carrier of information. Abstract: Modern material media of documented information, their classification and characteristics

SuperDisk, ZIP, JAZ. The 3.5-inch floppy disk is the most common storage media in the world. There are two systems currently in development: Iomega's ZIP technology and Imation's SuperDisk (formerly called LS-120).

SuperDisk provides the ability to store 120 MB of information and is almost identical in appearance to a traditional 3.5-inch floppy disk. The storage medium is inexpensive and “compatible in both directions”, i.e. The new drives can also read and write classic 1.44 MB floppy disks.

Iomega ZIP floppy disks have a capacity of 100 to 250 MB and are comparable in price to SuperDisk media. ZIP floppy disks are currently very common in the publishing industry, from which we can conclude that there is a corresponding need for removable media of this type. ZIP is not "both ways compatible" and the drive can only handle ZIP media. The access time for information on a ZIP disk is shorter than that of a SuperDisk disk.

3.5-inch "JAZ" floppy disks from Iomega have a storage capacity of up to 2 GB. Magneto-optical disk (CD-MO). Magneto-optical media, called MO for short, have become widespread. The memory capacity clearly speaks in favor of this technology: 640 MB on a 3.5-inch drive and 2.6 GB on a 5.25-inch drive. Their development is fast. Already today, manufacturers such as Sony and Philips are talking about a capacity of 2.6 GB for 3.5-inch media and 10.4 GB for 5.25-inch media. MO drives achieve data transfer rates of 4 MB/s and average access times of less than 25 ms. Data placement and recording are carried out using a laser.

Hard drives. Finally, we should mention hard drives, which come standard with almost every computer. The memory capacity of these storage media is constantly increasing and has recently reached about 80 GB for a 31/2’’ disk.

Introduction………………………………………………………………………………………...3

Storage media……………………………………………………………4

Encoding and reading information..……………………………………9

Development prospects…………………….…………………………………….15

Conclusion………………………………………………………………………………….18

Literature…………………………………………………………………………………19

Introduction

In 1945, John von Neumann (1903-1957), an American scientist, came up with the idea of ​​using external storage devices to store programs and data. Neumann developed a structural schematic diagram computer. All modern computers follow Neumann's scheme.

External memory is designed for long-term storage programs and data. External memory devices (drives) are non-volatile; turning off the power does not lead to data loss. They can be built into system unit or made in the form of independent blocks connected to the system through its ports. Based on the method of recording and reading, drives are divided, depending on the type of media, into magnetic, optical and magneto-optical.

Information coding is the process of forming a specific representation of information. A computer can only process information presented in numerical form. All other information (for example, sounds, images, instrument readings, etc.) must be converted into numerical form for processing on a computer. As a rule, all numbers in a computer are represented using zeros and ones (not ten digits, as is usual for people). In other words, computers usually work in the binary number system, since this makes the devices for processing them much simpler.

Reading information is retrieving information stored in a storage device (memory) and transferring it to other devices of the computer. Information is read during most machine operations, and sometimes is an independent operation.

During the abstract, we will consider the main types of information carriers, encoding and reading information, as well as development prospects.

Storage media

Historically, the first storage media were punched tape and punched card input/output devices. Following them came external recording devices in the form of magnetic tapes, removable and permanent magnetic disks and magnetic drums.

Magnetic tapes are stored and used wound on reels. There were two types of coils: feeding and receiving. Tapes are supplied to users on feed reels and do not require additional rewinding when installing them in drives. The tape is wound onto a reel with the working layer inward. Magnetic tapes are classified as indirect access storage devices. This means that the search time for any record depends on its location on the media, since the physical record does not have its own address and in order to view it you need to view the previous ones. Direct access storage devices include magnetic disks and magnetic drums. Their main feature is that the search time for any record does not depend on its location on the media. Each physical record on the medium has an address that allows direct access to it, bypassing other records. The next type of recording devices were packages of removable magnetic disks, consisting of six aluminum disks. The capacity of the entire package was 7.25 MB.

Let's take a closer look at modern storage media.

1. Floppy magnetic disk drive (FMD – disk drive).

This device uses flexible magnetic disks as a storage medium - floppy disks, which can be 5 or 3 inches. A floppy disk is a magnetic disk, like a record, placed in an “envelope.” Depending on the size of the floppy disk, its capacity in bytes varies. If a standard 5'25" floppy disk can hold up to 720 KB of information, then a 3'5" floppy disk will hold 1.44 MB. Floppy disks are universal, suitable for any computer of the same class equipped with a disk drive, and can be used for storing, accumulating, distributing and processing information. The drive is a parallel access device, so all files are equally easily accessible. The disk is covered on top with a special magnetic layer, which ensures data storage. Information is recorded on both sides of the disk along tracks that are concentric circles. Each track is divided into sectors. The data recording density depends on the density of tracks on the surface, i.e., the number of tracks on the surface of the disk, as well as on the density of information recording along the track. The disadvantages include small capacity, which makes long-term storage of large amounts of information almost impossible, and the not very high reliability of the floppy disks themselves. Currently, floppy disks are practically not used.

2. Hard magnetic disk drive (HDD - hard drive)

It is a logical continuation of the development of magnetic information storage technology. Main advantages:

– large capacity;

– simplicity and reliability of use;

– the ability to access multiple files simultaneously;

– high speed access to data.

The only disadvantage we can highlight is the lack of removable storage media, although external hard drives and backup systems are currently used.

The computer provides the ability, using a special system program conditionally split one disk into several. Such disks, which do not exist as a separate physical device, but represent only part of one physical disk, are called logical disks. Logical drives names are assigned, which are letters of the Latin alphabet [C:], , [E:], etc.

3. Compact disc reader (CD-ROM)

These devices use the principle of reading grooves on a metallized carrier layer of a compact disc with a focused laser beam. This principle makes it possible to achieve a high density of information recording, and, consequently, a large capacity with minimal dimensions. A CD is an excellent means of storing information, it is cheap, practically not subject to any environmental influences, the information recorded on it will not be distorted or erased until the disk is physically destroyed, its capacity is 650 MB. It has only one drawback - the relatively small amount of information storage.

4. DVD

A) Differences between DVD and regular CD-ROM

The most basic difference is, naturally, the amount of information recorded. If you can write 650 MB onto a regular CD (although recently there are discs with 800 MB, but not all drives can read what is written on such a medium), then one DVD will fit from 4.7 to 17 GB. DVD uses a laser with a shorter wavelength, which has significantly increased the recording density, and in addition, DVD implies the possibility of two-layer information recording, that is, on the surface of the compact there is one layer, on top of which another, translucent one is applied, and the first is read through the second in parallel . There are also more differences in the media themselves than seems at first glance. Due to the fact that the recording density has increased significantly and the wavelength has become shorter, the requirements for the protective layer have also changed - for DVD it is 0.6 mm versus 1.2 mm for regular CDs. Naturally, a disk of such thickness will be much more fragile compared to a classic blank. Therefore, another 0.6 mm is usually filled with plastic on both sides to get the same 1.2 mm. But the main bonus of such a protective layer is that, thanks to its small size, it became possible to record information on both sides on one compact, that is, to double its capacity, while leaving the dimensions almost the same.

B) DVD capacity

There are five types of DVDs:

1. DVD5 – single-layer, single-sided disc, 4.7 GB, or two hours of video;

2. DVD9 – double-layer single-sided disc, 8.5 GB, or four hours of video;

3. DVD10 – single-layer double-sided disc, 9.4 GB, or 4.5 hours of video;

4. DVD14 – double-sided disc, two layers on one side and one on the other side, 13.24 GB, or 6.5 hours of video;

5. DVD18 – double-layer, double-sided disc, 17 GB, or more than eight hours of video.

The most popular standards are DVD5 and DVD9.

IN) Possibilities

The situation with DVD media now resembles that of CDs, which for a long time also only stored music. Now you can find not only films, but also music (so-called DVD-Audio) and software collections, games, and films. Naturally, the main area of ​​use is film production.

G) Sound in DVD

Audio can be encoded in many formats. The most famous and frequently used are Dolby Prologic, DTS and Dolby Digital of all versions. That is, in fact, in the formats used in cinemas to obtain the most accurate and colorful sound picture.

D) Mechanical damage

CD and DVD discs are equally sensitive to mechanical damage. That is, a scratch is a scratch. However, due to the much higher recording density, the losses on the DVD disc will be more significant. Now there are programs that can recover information even from damaged disks, although they skip damaged sectors.

The rapidly growing market for portable hard drives designed to transport large amounts of data has attracted the attention of one of the largest hard drive manufacturers. Western Digital has announced the release of two device models called WD Passport Portable Drive. Options with a capacity of 40 and 80 GB are on sale. WD Passport Portable Drives are based on 2.5-inch WD Scorpio EIDE HDDs. They are packaged in a rugged case, equipped with support for Data Lifeguard technology, and do not require an additional power source (powered via USB). The manufacturer notes that the drives do not heat up, operate quietly and consume little energy.

1. Information carrier as a material component of a document

Information itself is not a sufficient feature of a document. The material component is one of the two necessary and mandatory components of a document, without which it cannot exist. The material component of a document is its material (physical) essence, the form of the document, ensuring its ability to store and transmit information in space and time. The material component of a document is determined by the material carrier of information - material objects in which information (data) is reflected in the form of symbols, images, signals, technical solutions and processes.

The purpose of a document for storing and transmitting information in space and time determines its specific material design, presented in the form of books, newspapers, booklets, microfiche, films, disks, floppy disks, etc.

This special design ensures that documents fulfill their main function, making it possible to be convenient for movement in space, stable for storing information over time, and adapted for the physiological ability to read a message.

The information contained in the document is necessarily fixed on some special material (paper, film, video, audio, photographic film, etc.) that has a certain form of media (tape, sheet, card, drum, disk, etc.) .p.). In addition, information is always recorded in some way of recording, which requires the presence of media (paint, ink, ink, dyes, glue, etc.) and tools (pen, printing press, video camera, printer, etc.).

The material basis of a document is a set of materials used to record a message (text, sound, image) and making up the information carrier. Depending on the material basis, documents are divided into two large groups: natural and artificial. Artificial ones, in turn, are divided into paper documents and documents on a non-paper basis - polymer documents (polymer-film and polymer-plate).

The most common type is paper-based media. Most modern documents functioning in society are made on paper or paper substitutes. They are called paper, i.e. having paper media.

In these media, information is displayed in the form of symbols and images. Such information is classified as documented information and represents various types of documents.

Paper documents include business documents, scientific and technical documentation, books, magazines, newspapers, manuscripts, maps, sheet music, art publications, punched tapes, punched cards, etc.

The paper meets many requirements: it is relatively easy to manufacture, affordable, moderately durable, can be stored for a long time and makes it easy to record information. The most valuable quality of paper is that it allows you to replicate information. The mass dissemination of information through printing became possible only as a result of the industrial production of paper.

The emergence of artificial polymer-based media (shellac, polychrome vinyl, semiconductor, biomass) has expanded the diversity of documents capable of carrying audio speech, music, moving and three-dimensional images. gramophone records, magnetic films, photographic and film films, magnetic and optical discs- tangible media of such information that cannot be recorded on paper.

Polymer film documents include: film documents (film, film, video), photographic documents (diapositive, microfilm, microcard, microfiche), phonodocuments (magnetic phonograms for recording images and sound), documents for use in a computer (punched tape).

The group of polymer-plate documents consists of: a flexible magnetic disk, a magnetic card, a flexible and rigid gramophone record, an optical disk - both hard and soft.

The transmission of documented information in time and space is directly related to the physical characteristics of its material carrier. 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 exposed to numerous negative influences due to changes in temperature, humidity, light, biological processes, etc.

Therefore, it is no coincidence that the problem of the durability of material storage media has always attracted the attention of participants in the documentation process. Already in ancient times, there was a desire to record the most important information on relatively durable materials such as stone and metal.

During the documentation process, there was a desire to use high-quality, durable paints and inks.

However, solving the problem of durability, a person was immediately forced to deal with another problem, which was that durable storage media were, as a rule, more expensive. Therefore, we constantly had to look for the optimal balance between the durability of a material storage medium and its cost. This problem still remains very important and relevant.

The most common material carrier of documented information at present - paper - is relatively cheap, accessible, and satisfies necessary requirements in terms of quality, etc. However, at the same time, paper is a flammable material, it is afraid of excessive humidity, mold, sunlight, and requires certain sanitary and biological conditions. The use of insufficiently high-quality ink or paint leads to the gradual fading of the text on the paper.

At the end of the 20th century, with the development of computer technology and the use of printers to output information onto paper, the problem of the durability of paper documents again arose. The fact is that many modern printed texts on printers are water-soluble and fade. More durable inks, in particular for inkjet printers, are naturally more expensive, and therefore less accessible to the mass consumer. Material media of documented information therefore require appropriate conditions for their storage.

Thus, by the material component of a document we mean: 1) the material basis of the document; 2) the form of the information carrier and 3) the method of documenting or recording the information.

2. Form of material carrier of electronic information

Scientific and technological progress has led to the emergence of so-called electronic documentation. Its specificity lies in the fact that a person cannot perceive an electronic document in the physical form in which it is recorded on the medium.

In addition, electronic documents are directly dependent on information technology, which have an irreversible tendency to change and become obsolete with scientific and technological progress in the field of technology and software. In this regard, there is a great danger of losing access to such documents after a certain period of time.

Despite the widespread use of the term “electronic document” in literature and practice, its definition has not yet been established. At the same time, a number of authors believe that an electronic document is “a document whose carrier is an electronic medium - a magnetic disk, magnetic tape, CD, etc.”

In the concept of an electronic document, three well-known components can be distinguished: recorded information, media, identification details, which does not go beyond existing definition document.

Unfortunately, unlike information recorded on paper, information on machine-readable media can be easily changed without the desire of its author as a result of unauthorized access to it by an outsider, and without any traces of such interference.

The problem arose of establishing the evidentiary value of a machine-readable document.

The classical legal interpretation of the term document (from the Latin documentum - evidence) is associated with the written form of storing information. Indeed, in traditional paper documents, the details and content of the document are inextricably linked with the material carrier of the document.

In electronic documents, each of these components is relatively independent, which is due to the peculiarities of their production, processing, storage and transmission. This feature largely determines the specifics of the legal status of electronic documents.

The legal features of a document on computer media are:

· computer storage medium;

· computer information;

· details that allow you to identify the form and content of computer information.

For the category of electronic document, a clear legislative regulation of its details is of particular importance, since they are the ones who give information on a tangible medium the status of a document.

The technology for producing, storing and transmitting electronic documents is fundamentally different from written documents, and for this reason, details that successfully perform their functions in traditional documents (manager’s signature, seal, bank details of the parties, letterheads, etc.) are not always acceptable for them. In relation to electronic documents, only an electronic digital signature can fully perform the functions of a requisite.

The distribution of documented information provided with an electronic digital signature in communication and telecommunications systems is similar to the distribution of original documents on paper using traditional methods.

Distribution of documented information on machine-readable media without electronic digital signature or other similar means of identification, such as transmission or oral information, the identity of which to a hypothetical original can be confirmed by the testimony of witnesses, or a copy of a document in respect of which it is required possible ways prove its compliance with the original.

Thus, for a management document, the information carrier is essential. Document information carriers change with technological progress. With the development of new information technologies, so-called electronic documents appear, the storage media of which are fundamentally different from “paper” ones.

The translation of information into machine-readable media instead of paper required the introduction of new mechanisms to ensure the “legal force” or “evidential value” of a document on such a medium, for example, an electronic digital signature.

. Classification of documents on modern tangible media

Informatization of society, rapid development of micrography, computer equipment and its penetration into all spheres of human activity determined the appearance of documents on non-paper media.

These documents, unlike traditional ones, i.e. paper, as a rule, require for reproduction of information use technical means. This group includes documents in the form of films, microfiche, audio magnetic recordings, as well as in the form of discrete media for computer reading (disks, floppy disks), etc.

Information media on punched tapes, punched cards, magnetic and optical media, as well as other documents intended for translation into another language system are usually classified as matrix documents. Documents on these storage 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 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 (perforation, matrix magnetic recording, matrix arrangement of characters, numbers, etc.) adapted for automatic reading. Information is recorded on punched cards or tapes, magnetic tapes, cards, floppy disks, special forms and similar media.

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

From the entire array of existing documents, the group under consideration is distinguished by the method of recording and reading information. In accordance with this criterion, documents on the latest storage media are divided into:

· documents on punched storage media (punched documents), which include punched cards, punched tapes, aperture cards;

· documents on magnetic storage media (magnetic documents), which include magnetic tapes, magnetic cards, floppy and hard magnetic disks, as well as video disks;

· documents on optical storage media (optical documents), a group of which consists of micrographic documents (microfilms, microdisks, microcards) and optical disks;

· documents on holographic storage media (holographic documents). These include holograms.

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 write and read part of the information it contains by means computer technology(filled out special forms, forms, questionnaires, etc.);

· a machine-readable document suitable for automatically reading the information it contains using a scanner (text, graphic and other types of recording, postal code);

· a document on a machine-readable medium, created by computer technology, recorded on a machine-readable medium: magnetic tape (MT), magnetic disk (MD), floppy disk, optical disk, etc. - and executed in accordance with the established procedure;

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

· a document on a 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.

. Characteristics of material storage media and their development

The advent of writing stimulated the search and invention of special materials for writing. however, at first, people used for this purpose the most accessible materials that could be found without much effort in the environment: palm leaves, shells, tree bark, tortoiseshells, bones, stone, bamboo, etc. for example, the philosophical instructions of Confucius (mid-1st millennium BC) were originally written down on bamboo tablets. in Ancient Greece and Rome, along with wooden tablets coated with a layer of wax, metal (bronze or lead) tables were also used, in India - copper plates, and in Ancient China - bronze vases and silk.

On the territory of Ancient Rus' they wrote on birch bark - birch bark. To date, over 1 thousand birch bark documents from that time have been found, the oldest of which dates back to the first half of the 11th century. archaeologists have even discovered a miniature birch bark book of twelve pages, in which double sheets are sewn along the fold. Preparing the birch bark for the recording process was straightforward. It was first boiled, then the inner layer of bark was scraped off and the edges were trimmed. the result was a document base material in the form of a ribbon or rectangle. The certificates were rolled up into a scroll. In this case, the text appeared on the outside.

They wrote on birch bark not only in Ancient Rus', but also in Central and Northern Europe. Birch bark letters in Latin were discovered. There is a known case when in 1594 30 pounds of birch bark for writing was even sold by our country to Persia.

The main material for writing among the peoples of Western Asia was originally clay, from which slightly convex tiles were made. After applying the necessary information (in the form of wedge-shaped signs), the raw clay tiles were dried or fired, and then placed in special wooden or clay boxes or in peculiar clay envelopes.

The use of natural materials for writing purposes also occurred in later times. For example, in remote corners of Russia, even in the 18th century, people sometimes wrote on birch bark.

Historically, the first material specifically made for writing was papyrus. Its invention was around the middle of the third millennium BC. became one of the most important achievements of Egyptian culture. The main advantages of papyrus were compactness and lightness. Papyrus was made from the loose core of Nile reed stems in the form of thin yellowish sheets, which were then glued into strips with an average length of 10 m (their dimensions reached 40 m or more) and a width of up to 30 cm. Due to its high fragility, writing on papyrus was carried out with one side, and kept it in the form of a scroll.

Papyrus was used not only in Ancient Egypt, but also in other Mediterranean countries, and in Western Europe - until the 20th century.

Another material carrier of plant origin was tapa. Tapa was mainly used in the equatorial zone (in Central America, on the Hawaiian Islands). It was made from bast, bast, in particular, paper mulberry tree. The bast was washed, cleared of irregularities, and then beaten with a hammer, smoothed and dried. The most famous material of animal origin, specially made for the purpose of writing and which became widespread in the ancient and medieval eras, was parchment. Unlike papyrus, which was produced only in Egypt, parchment could be obtained in any country, since it was made from animal skins by cleaning, washing, drying, stretching, followed by processing with chalk and pumice. In our country, parchment began to be made only in the 15th century, and before that it was brought from abroad.

parchment could be written on both sides. It was much stronger and more durable than papyrus. However, parchment was a very expensive material. This significant drawback of parchment was overcome only as a result of the advent of paper.

Paper (from Italian "" - cotton) was invented in China in the 2nd century BC. In 105, the Chinese Cai Lun improved the process of its production, proposing to use young shoots of bamboo, bark of mulberry trees, willow, as well as hemp and rags as raw materials.

Only at the beginning of the 7th century the secret of making paper became known in Korea and Japan, then in other countries of the East, and in the 12th century - in Europe.

In Rus', the use of this material for writing began in the 14th century. Initially, paper was imported, but during the reign of Ivan IV, the first “paper mill” was built in Russia near Moscow, which existed for a short time. But already in the 17th century there were 5 paper-making enterprises in the country, and in the 18th century - 52.

Until the mid-19th century, almost all European, including Russian, paper was made from linen rags. It was washed, boiled with soda, caustic soda or lime, heavily diluted with water and ground in special mills. Then the liquid mass was scooped out with a special rectangular shape with a wire mesh attached to it. After the water drained, a thin layer of paper pulp remained on the metal sieve. The wet paper sheets thus obtained were placed between pieces of coarse cloth or felt, the water was squeezed out using a press and dried.

The metal threads of the mesh left marks on hand-made paper that were visible in the light, since the paper pulp in the places where it came into contact with the wire was less dense. These marks are called filigree or watermark.

To date, about 175 thousand filigree pieces are known, made at different times in paper mills and manufactories. Watermarks were a trademark, as well as one of the means of protection against document forgery.

Meanwhile, paper production was improved and gradually mechanized. In 1670, a roll was invented in Holland - a mechanism for grinding fibers. The French chemist Claude Louis Berthollet in 1789 proposed a method of bleaching rags with chlorine, which helps improve the quality of paper. And in 1798 the Frenchman N.L. Robber received a patent for the invention of a paper-making machine. In Russia, the first such machine was installed in 1818 at the Peterhof paper mill. Currently, the operating principle of paper making machines remains the same as hundreds of years ago. However, modern machines have much greater productivity.

The most important step in the development of papermaking was the production of paper from wood starting in 1845. This discovery is associated with the name of the Saxon weaver F. Keller. Wood raw materials are becoming the main one in the paper industry.

In the 20th century, the improvement of paper storage media continued. Since the 1950s In the production of paper, polymer films and synthetic fibers began to be used, as a result of which a fundamentally new, synthetic paper appeared - plastic paper. It is characterized by increased mechanical strength, resistance to chemical influences, heat resistance, durability, high elasticity and some other valuable qualities.

The development of material carriers of documented information generally follows the path of a continuous search for objects with high durability, large information capacity with minimal physical dimensions of the medium. Since the 1980s, optical (laser) disks have become increasingly widespread. These are plastic or aluminum discs designed to record and reproduce information using a laser beam.

Currently, optical (laser) disks are the most reliable material carriers of documented information recorded digitally.

The optical disc was first developed and demonstrated in 1979 by Philips. First optical recording sound programs for household purposes was implemented in 1982 by Sony in laser CD players, which began to be designated by the abbreviation CD (Compact Disk).

In the mid-1980s. CDs with permanent memory were created - CD - ROM (Compact Disk - Read Only Memory). Since 1995, rewritable optical compact discs began to be used: CD - R (CD Recordable) and CD - E (CD Erasable).

The optical document accumulates the advantages in various ways recording information and media materials. An important advantage of this information carrier is, firstly, its versatility, i.e. the ability to record and store information of any kind in a single digital form - audio, text, graphics, video. Secondly, an optical document makes it possible to organize and store information in the form of databases on a single optical medium. Thirdly, this document provides the possibility of creating integrated information networks that provide access to such databases.

An optical document is an integral type of document that can absorb the advantages and capabilities of a book, video, and audio recording at the same time. It is necessary for long-term storage of large amounts of information.

The most promising type of optical document, distinguished by the shape of the medium and features of use, is an optical disk - a material medium on which information is written and read using a focused laser beam.

CDs are made of 1.2 mm thick polycarbonate, coated with a thin layer of aluminum (previously gold was used) with a protective layer of varnish, on which the label is usually printed.

Based on application technology, optical, magneto-optical and digital compact discs are divided into 3 main classes:

1.Discs that allow single recording and repeated playback of signals without the possibility of erasing them (CD-R; CD-WORM - Write - Once, Read - Many - recorded once, counted many times). Used in electronic archives and data banks, in external drives COMPUTER.

2.Reversible optical discs that allow you to repeatedly record, play back and erase signals (CD-RW, CD-E). These are the most versatile disks, capable of replacing magnetic media in almost all applications.

.Digital universal video discs DVD (Digital Versatile Disk) such as DVD-ROM, DVD-RAM, DVD-R with large capacity (up to 17 GB).

At the same time, work is actively underway to create even more compact storage media using so-called nanotechnologies 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 nanotechnology can replace thousands of laser discs.

Thus, the introduction of optical technology into the document and information sphere can be considered as the beginning new era in the distribution, storage, and use of documented information.

Classification of material magnetic recording media:

· geometric shape and size (shape of tape, disk, card, etc.);

· by the internal structure of the carriers (two or several layers of different materials);

· by magnetic recording method (media for longitudinal and perpendicular recording);

· by type of signal being recorded (for direct recording analog signals, for modulation recording, for digital recording).

The very first magnetic recording medium on which information was recorded in Poulsen’s devices at the turn of the 19th-20th centuries was steel wire with a diameter of up to 1 mm. At the beginning of the 20th century, rolled steel strip was also used for these purposes. However quality characteristics of these carriers were very low. Suffice it to say that to produce a 14-hour magnetic recording of reports at the International Congress in Copenhagen in 1908, 2,500 km of wire weighing about 100 kg were required. In addition, in the process of using wire and steel tape, an intractable problem arose of connecting their individual pieces. The steel magnetic disk, the first patent for which was issued back in 1906, was not used then.

Only in the second half of the 1920s, when powder magnetic tape was invented, did the large-scale use of magnetic recording begin. A patent for the technology of applying ferromagnetic powder to film was received in 1928 by Fritz Pfeimer in Germany. Initially, magnetic powder was applied to a paper substrate, then to cellulose acetate, until the use of high-strength material, polyethylene terephthalate (lavsna), as a substrate began. The quality of magnetic powder has also improved. In particular, iron oxide powders with the addition of cobalt, chromium oxide, metal magnetic powders of iron and its alloys began to be used, which made it possible to increase the recording density several times. The working layer is applied to the substrate by vacuum deposition or electrolytic deposition in the form of magnetic powder, binder, solvent, plasticizer and various additives.

In addition to the flexible base of the working magnetic layer, the tape may also have additional layers: protective - on the surface of the working layer and anti-friction - on the back side of the tape, in order to protect the working layer from mechanical wear, increase the mechanical strength of the tape and improve its sliding along the surface of the magnetic head . The anti-friction layer also removes electrical charges that accumulate on the magnetic tape. The intermediate (sublayer) between the base and the working layer serves to improve the adhesion of the working and antifriction layers to the base.

Unlike mechanical recording media, magnetic tape is suitable for repeated recording of information. The number of such recordings is very large and is limited only by the mechanical strength of the magnetic tape itself. The first tape recorders, which appeared in the 1930s, were reel-to-reel. In them, magnetic tape was wound on reels.

In 1963, Philips developed cassette recording, which made it possible to use very thin magnetic tapes. Their maximum thickness is only 20 microns with a width of 3.81 mm. In cassette recorders, both reels are contained in a special compact cassette and the end of the film is pre-attached to an empty reel. Recording lengths on compact cassettes are usually 60, 90 and 120 minutes.

At the end of the 1970s. microcassettes with dimensions of 50*33*8 mm appeared, i.e. the size of a matchbox, for portable voice recorders and telephones with answering machines, and in the mid-190s. - picocassettes are three times smaller than microcassettes.

Since 1952, magnetic tape began to be used for storing information in electronic computers. The advantage of magnetic tape is the ability to record in density due to the fact that the total surface area of ​​the magnetic layer of the tape is significantly higher than that of other types of media, and is limited only by the length of the tape. Cassette tape drives - cartridges can reach a capacity of up to 40 GB.

At first, electronic computers also used magnetic drums.

Since the early 1960s. Magnetic disks are widely used, primarily in computer storage devices; currently they are most used in working with documented information.

A magnetic disk is an information carrier in the form of a disk with a ferrimagnetic coating for recording. Magnetic disks are divided into hard and flexible (floppy disks).

A hard magnetic disk (hard drive) is a round flat plate made of solid material (metal) coated with a ferrimagnetic layer. It is designed for permanent storage of information used when working with a personal computer and 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 mode of operation, and provides effective support for the mechanism virtual memory.

A floppy disk (floppy disk) or floppy disk is a disk made of plastic coated with a ferrimagnetic layer. Flexible magnetic disk is widely used in personal computers and is a removable carrier of documented information. It is stored outside the computer and installed on the drive as needed.

Currently, the most commonly used floppy disks are those with a capacity of 1.44 MB. They allow you to transfer documents and programs from one computer to another, store information that is not constantly used on the computer, make archival copies of information contained on hard drives.

The so-called plastic cards, which are devices for magnetic storage of information and data management.

A plastic card is a document made of metal, paper or plastic of a standard rectangular shape, at least one of the details of which is in a form understandable by electronic computing and telecommunications. There are two types of plastic cards: simple and smart. Simple cards have only a magnetic memory that allows you to enter data and change it. In smart cards, which are sometimes called smart cards (from the English smart - smart), in addition to memory, a microprocessor is also built in. It makes it possible to make the necessary calculations and makes plastic cards multifunctional.

Technologies and material media for magnetic recording are constantly being improved. In particular, there is a tendency to increase the density of information recording on magnetic disks while reducing its size and reducing the average access time to information.

On a perforated document, information is recorded by perforating (punching) holes (perforations) or cutting out the corresponding sections of the material carrier.

Depending on their purpose, documents on punched media are divided into three types:

1.for management automatic devices when performing various operations during the manufacturing and control of designed products;

2.for managing, processing, converting information when designing products on a computer;

.for use in processing and conversion.

Recording information on perforated documents can be done on a continuous tape or on cards, which are like pieces of such a tape, or on a plane on which information is recorded using the punching method. Therefore, according to the material design of the carrier, perforated documents are divided into card documents (punched cards, aperture cards) and tape documents (punched tapes).

Punched cards and punched tapes can be grouped into types according to the following criteria:

· channel of perception - punched cards and punched tapes are visual documents;

· material basis - artificial, paper, less often plastic (punched cards) and celluloid or lavsan (punched tape);

· intended for perception, a distinction is made between machine-readable (machine-sorted punched cards) and human-readable (manually sorted punched cards);

· Based on the location of the matrix, punched cards with edge and internal perforation are distinguished;

· encoding method - cut-out with perforation cut during the encoding process, and punched with perforation obtained during encoding;

· processing method - manual and machine sorting punched cards;

According to their intended purpose, perforated documents can be divided into accounting, reference, bibliographic, informational, diagnostic, and educational.

A punched card or punched card is a perforated information carrier in the form of a rectangular card made of thin cardboard, thick paper or plastic, designed for recording information by punching holes (perforations) or cutting out its corresponding sections.

Punched cards are used mainly for input and output of data into a computer, and also as the main recording medium in punched computing systems. There are a large number of types of punched cards, differing in shape, size, volume of stored information, shape and location of holes.

Perforated tape, punched tape - a carrier of information in the form of a tape (paper, celluloid or lavsan), on which data is applied with a certain sequence of code combinations of holes. Each code combination encodes one character and is placed on the tape perpendicular to the direction of its movement.

Punched paper tape can be used:

· when transmitting or receiving telegraph dispatches;

· when working on computers and other organizing equipment (writing, summing, accounting, etc.), on special decoders or in a computer output device;

· as a record of scientific and technical information, etc. on various machines and devices.

In the 19th century, in connection with the invention of technotronic methods and means of documentation, many fundamentally new media of information became widespread. Historically, the first of these were photographic media, which appeared in the first half of the 19th century. Photographic materials are flexible films, plates, papers, and fabrics. Essentially, these are complex polymer systems, consisting, as a rule, of the following layers: a substrate (base) with a thickness of about 0.06 mm (if polyethylene terephthalate is used), on which an underlayer (about 1 micron thick) is applied, as well as a photosensitive an emulsion layer - gelatin with silver halide microcrystals evenly distributed in it (on color photographic films up to 0.05 mm, on photographic papers - up to 0.012 mm) and an anti-halo layer.

Color photographic media have a more complex structure, since they also contain blue-, yellow-, green-, and red-sensitive layers. For the first time, three-layer color photographic materials were developed and released in 1935 by the American company Eastman Kodak. Subsequently, the improvement of multilayer colored materials continued. The developments of the 1950s were important, being one of the qualitative leaps in the history of photography, predetermining the rapid development and wide dissemination of color photography.

In recent years, new scientific ideas have emerged that create the basis for a significant increase in the photosensitivity of materials and bringing it to the photosensitivity of the human eye.

In addition to photosensitivity, the most important characteristics of photographic materials, in particular photographic films, are also graininess, contrast, and color sensitivity.

Until recently, photographic plates were also used for scientific and reproductive purposes, where the working layer was applied to a transparent glass base, which does not deform during chemical photographic processing and ensures accurate transfer of the positive image.

Film is a photographic material on a flexible transparent substrate that has holes on one or both edges - perforations. Historically, the first light-sensitive tape media were paper-based. The cellulose nitrate tape used at first was a very flammable material. However, already in 1897, the German scientist Weber produced a film with a non-flammable base of cellulose triacetate, which became widespread, including in the domestic film industry. Subsequently, the substrate began to be made of polyethylene terephlate and other elastic polymer materials. In our country, the first samples of film were produced in 1919, and in 1930 its industrial production began.

By comparison. with photographic film, the film film is usually made up of many layers. A sublayer is applied to the substrate, which serves to secure the photosensitive layer (or several layers) to the base. In addition, film usually has an anti-halo, anti-curl, and protective layer.

Films come in black and white and color. Color film films are also multi-component polymer systems.

Films are divided into:

·negative;

· positive (for contact and projection printing);

· convertible (can be used to obtain negatives and positives);

· countertype (for copying, for example, for mass production of film copies);

hydrotypic;

· phonogram (for photographic recording of sound).

Black and white photographic film, available in 16mm and 35mm widths, is the most common medium for microfilm production. Microfilm is a microform on a roll of photosensitive film with a sequential arrangement of frames in one or two rows. The main types of microfilm are roll and cut microfilm. Microfilm in a segment is a part of a roll film at least 230 mm long, on which up to several dozen frames are placed.

Documents on microforms also include microcards, microfiches and ultra-microfiches, which are actually flat format microfilms:

· microcard - a document in the form of a microform on an opaque format material, obtained by copying onto photographic paper or micro-offset printing;

· microfiche - a sheet of transparent photographic film of 105*148 mm format with a sequential arrangement of frames in several rows;

· ultramicrofiche - microfiche containing copies of images of objects with a reduction of more than 90 times. For example, the capacity of ultra-microfiche measuring 75*125 mm is 936 book-size pages.

Despite the widespread use of digital photo and video documentation in recent decades, traditional photographic media continue to maintain their niche in the domestic and foreign market of physical information media, providing high quality at a relatively low price.

In the array of documents, a special place is occupied by information carriers containing one or more microimages, collectively called micrographic documents or microforms.

A micrographic document is made on a microcarrier of a microcopy or original document. This class of documents consists of microfilms, microfiche and microcards.

Micrographic documents or microforms are produced in compact form on photo, film, tape or optical disk. Their distinctive features are small physical dimensions and weight, significant information capacity, compact storage of information, and the need for special equipment to read it. The predicted service life of microforms is 500 years or more.

Microfilm is a reduced copy of a document obtained photographically. It contains one or more text and graphic microimages, united by a common content.

Microfiche is a flat microform with microimages arranged in a grid. Microfiche is a piece of photo-, diazo-, or vesicular film of a standard format, on which a microimage is located in a given sequence. You can read microfiche on a reading machine using an overhead projector.

Microcard is an information carrier on photographic film inserted into an aperture or classer card. This is a document made on an opaque base (on a piece of photographic or plain paper, as well as on a metal base). The microcard is read on reading machines using an epiprojector (i.e. in reflected light). In a microcard, you can use both the front and back sides, placing on one side a search image of the document, bibliographic description, annotation or abstract of the document, and on the other - a microimage of the entire document.

One of the most modern and promising storage media 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. Already the first CompactFlash (CF) cards had dimensions of 43*36*3.3 mm. And soon one of the smallest information storage devices appeared - the MultiMediaCard, only the size of a postage stamp and weighing less than two grams.

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 of up to 10,000, as well as from 10,000 to 1,000,000 cycles. All these types are not fundamentally different from each other. The only differences are in the architecture.

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 historically comes from semiconductor ROM (Read Only Memory) (or ROM - read-only memory). Flash memory technology appeared about 20 years ago, and industrial production began in the mid-1990s. In 1997, flash cards were first used in digital cameras. Almost immediately they became one of the main storage media, widely used in a wide variety of digital multimedia devices - in laptop computers, in printers, digital voice recorders, cell phones, electronic watches, notebooks, televisions, air conditioners, microwave ovens, washing machines, MP3 players, game consoles, digital photo and video cameras, etc.

Flash cards are one of the most promising types of material storage media. 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. static electricity.

Cards with a capacity of 4 GB have been released. They can hold about 4,000 high-resolution photographs, or 1,000 songs in MP3 format, or a full DVD movie. Meanwhile, a flash card with a capacity of 8 GB has already been developed.

The production of so-called stationary flash disks (in reality, they have a different shape from a disk) with a capacity of hundreds of MB, which are also mobile devices for storing and transporting information. For example, the Canyon Flash Drive has dimensions of 63*15*8.1 mm and weighs only 8g. These media easily connect to your computer.

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.

The volumetric image of information is currently recorded on holographic media. For holographic photography, special plates or films are used. They allow information to be condensed onto a tangible medium. Thus, one hologram measuring 101*126 mm can accommodate more than a thousand microholograms with a diameter of only 102 mm, which corresponds to several thousand pages of text.

The quality of a holographic image depends on the resolution of the photographic material and is determined by the number of interference lines recorded per 1 mm. The fact is that the light wavelength is very short, therefore, the distance between the interference maxima is also small and reaches only 1 micron. Hence, the greater the number of interference lines, the higher the image quality. Therefore, to record information in holography, fine-grained photographic emulsions with high resolution (1000 lines per 1 mm or more) are used.

Currently, the search is underway for grain-free photographic materials capable of recording a continuous distribution of the brightness of the interference pattern, in contrast to the discrete one, which is produced by grainy photographic emulsions, which are a suspension of photosensitive grains.

. Influence of storage medium type on document durability, cost and capacity

The transmission of information in time and space is directly related to the characteristics of its material carrier. It is no coincidence that the problem of durability of material storage media has always attracted the attention of participants in the documentation process. Already in ancient times, there was a desire to record the most important information on durable materials such as stone and metal.

In the process of recording information, there was a desire to use high-quality paints and durable inks. Largely thanks to this, many important textual historical monuments have reached us. And, conversely, the use of short-lived material media led to the irretrievable loss of most documents of the distant past.

However, while solving the problem of durability, almost immediately a problem arose that long-lasting storage media were, as a rule, more expensive. Therefore, we constantly had to look for the optimal balance between the durability of a material storage medium and its cost. This problem still remains very important and relevant.

The most common material medium of information today is paper. It is relatively cheap and accessible. However, at the same time, paper is a very short-lived material that can be subject to various influences.

Until the mid-19th century, paper was made from rag raw materials and contained long-fiber material with a high content of pure fiber, which provided it with high mechanical strength and durability. In the mid-19th century, according to experts, the first crisis period in the history of paper documents began. It was associated with the transition to making paper from wood, with the use of chemical fiber processing processes, with the use of synthetic dyes, with the widespread use of typewriting and copying tools.

As a result, the durability of a paper document was reduced from thousands to two hundred to three hundred years. Documents made on low-quality types and grades of paper are especially short-lived.

Thus, a certain pattern has emerged: improvements in paper production technology are accompanied by a decrease in the durability of the types of paper produced. By the way, no type of paper could surpass the durability of papyrus. The age of papyrus scrolls currently stored in libraries and museums in a number of countries is several millennia.

At the end of the 20th century, with the development of computer technology and the use of printers to output information onto paper, the problem of the durability of paper documents again arose. It is determined by such factors as the chemical stability of the paint, water resistance, resistance to physical and mechanical influences that cause abrasion, shedding and other defects.

Research has shown that documents created using dot-matrix printers are most suitable for long-term storage. Printouts from laser printers, as well as photocopying machines, are quite water-resistant and light-resistant. They are similar to black typescript, which was a fairly reliable means of text application. Inkjet printing, especially color printing, produces water-soluble and fading texts.

Not only printer inkjet texts are not sufficiently resistant to environmental influences. The same can be said for many modern handwritten texts, which are more water soluble and less lightfast than traditional ones.

In the USSR, a government program was even created that provided for the development and production of domestic durable papers for documents, special stable means of writing and copying, as well as limiting the use of short-lived materials for creating documents through regulations. In accordance with this program, by the 1990s. special durable papers for office work were developed and began to be produced. However, this program was not further developed.

The problem of durability and economic efficiency of material storage media has become especially acute with the advent of technotronic (audiovisual and machine-readable) documents, which are also subject to aging and require special storage conditions. Moreover, the aging process of such documents is multifaceted and differs significantly from the aging of traditional storage media.

First, audiovisual and machine-readable documents, as well as documents on traditional media, are subject to physical aging associated with the aging of the material medium. Thus, the aging of photographic materials manifests itself in changes in the properties of their photosensitivity and contrast during storage. In color photographic materials, fading occurs, which manifests itself in the form of distortion of colors and a decrease in their saturation.

Already from the moment film and photographic films are made, the process of their aging begins. At the same time, the film carrier is a relatively durable material.

The service life of gramophone records is determined by their mechanical wear and depends on the intensity of use and storage conditions.

Magnetic media are characterized by high sensitivity to external electromagnetic influences. They are also subject to physical aging and wear of the surface with an applied magnetic working layer. The ferromagnetic layer of the tapes is susceptible to corrosion. Magnetic tape stretches over time, causing the information recorded on it to become distorted. This is due to physical wear of the tape as a result of its contact with the magnetic head during the process of reading information. The magnetization of the tape gradually decreases, which leads to failures. As a result, the guaranteed storage life of information on magnetic tape is only 30 - 40 years. The same thing happens with floppy disks. Hard drives are more durable, with a service life of approximately 28 years. However, hard drives are electromechanical devices, which means they are more likely to break down.

The most reliable and durable today are optical storage media - SD-ROM, SD-R, DVD. Their service life is determined not by mechanical wear, like that of magnetic media, but by the chemical and physical stability of the environment in which they are located. Unlike magnetic disks, optical disks are completely independent of external magnetic fields. However, they also need optimal storage conditions. Mechanical damage to optical discs is contraindicated. Any deformation makes it impossible to read the information. Under optimal storage conditions, CDs can last up to 100 years.

Unlike traditional text and graphic documents, audiovisual and machine-readable documents are subject to technical aging associated with the level of development of information reading equipment. The rapid development of technology leads to problems arising in the reproduction of previously recorded information.

The introduction of electronic documentation into everyday life has led to the fact that technical aging has been supplemented by so-called logical aging, which is associated with the content of information, software and information security standards.

Technical and logical aging leads to the fact that a significant amount of information on electronic media is irretrievably lost.

Currently, the search for information-intensive and at the same time sufficiently stable and economic media continues. On one of scientific conferences, held in the USA, a Rosetta “eternal disk” made of nickel was demonstrated. It allows up to 350,000 pages of text and drawings to be stored in analog form for several thousand years.

Work is actively underway to create compact storage media using nanotechnology that works 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 storage media.

Conclusion

The goal of the course research was achieved by implementing the assigned tasks.

As a result of the research conducted on the topic “Modern material media for documented documentation,” a number of conclusions can be drawn:

The global informatization of society, the widespread dissemination of new information and communication technologies, the gradual introduction of market mechanisms and modern management have led to an increased role of information in socio-economic processes and its recognition as the most important strategic resource.

According to Russian legislation, information resources include documented information and information technologies, i.e. subject and means of information activity.

Documenting information - prerequisite for its inclusion in information resources - is carried out in the manner established by government bodies responsible for organizing office work, standardizing documents and their arrays, security Russian Federation.

With the help of documentation, information acquires the necessary properties and, in the form of documents, plays its main role in management processes, transferring management influences from the object to the subject of management and signaling a reverse reaction.

As a result of documentation, information is fixed (fixed) on a medium, acquires legal force, the possibility of identification, and evidence of its authenticity. Thus, the main form of organizing information in management is a document.

There are three main essential approaches to formulating the concept of a document: as a material object; as a carrier of information; as documented information. For a long time, the dominance of the term belonged to the bearer.

The modern understanding of a document brings to the fore the information component of the document and its legal support, which makes it possible to identify the document in the process of its functioning. Including a legal component in understanding a document allows you to implement the concept of document management at all stages of its life cycle.

For a management document, the information carrier is essential. Document information carriers change with technological progress. With the development of new information technologies, so-called electronic documents appear, the storage media of which are fundamentally different from “paper” ones.

A person is able to perceive an electronic document only with the help of special technological procedures and software. Electronic documents have physical and logical structure, which does not coincide with previous ideas about a document as a rigid, unchangeable structure of information and its carrier.

By the material component of the document we mean:

· the material basis of the document;

· form of the information carrier;

· a way of documenting or recording information.

Information carriers are closely connected not only with methods and means of documentation, but also with the development of technical thought. Hence the continuous evolution of types and types of material carriers.

The development of material carriers of documented information generally follows the path of a continuous search for objects with high durability, large information capacity with minimal physical dimensions of the medium.

List of sources

information medium material electronic

1.Bardaev E.A. Documentation: a textbook for students of higher educational institutions / E.A. Bardaev, V.D. Kravchenko. - M.: Publishing center "Academy", 2008. - 304 p.

2.Larkov, N.S. Documentation: textbook / N.S. Larkov. - M.: AST: East - West, 2006. - 427 p.

3.Stenyukov M.V. Documentation and office management (lecture notes). - M.: A - Prior, 2007. - 176 p. "Enumeration of modern storage media."

.Gutgarts R.D. Documentation of management activities: A course of lectures. - M.: INFRA - M, 2001. - 185 p. - (Series “Higher Education”).

.Basakov M.I. Office work; lecture notes / M.I. Basakov. - Ed. 7th, rev. and additional - Rostov n/d: Phoenix, 2009. - 192 p.

.Romanina L.A. Documentation support for management: for students of secondary vocational education institutions / L.A. Romanian. - 6th ed., sterling - M.: Publishing Center "Academy", 2008. - 224 p.

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Storage media – material that is intended for recording, storage and subsequent reproduction of information.

Storage medium - a strictly defined part of a specific information system, used for intermediate storage or transmission of information.

Storage medium is the physical environment in which it is recorded.

The media can be paper, photographic film, brain cells, punched cards, punched tapes, magnetic tapes and disks or computer memory cells. Modern technology offers more and more new types of storage media. They use the electrical, magnetic and optical properties of materials to encode information. Media are being developed in which information is recorded even at the level of individual molecules.

In modern society, three main types of information media can be distinguished:

1) Perforated - have a paper base, information is entered in the form of punches in the corresponding row and column. The volume of information is 800 bits or 100 KB;

2) Magnetic – they use flexible magnetic disks and cassette magnetic tapes;

3) optical.

Information carriers include:

Magnetic disks;

- magnetic drums- early variety computer memory, widely used in 1950-1960. Invented by Gustav Tauschek in 1932 in Austria. Later, the magnetic drum was replaced by memory on magnetic cores.

- floppy disks- a portable magnetic storage medium used for repeated recording and storage of relatively small data. Writing and reading is carried out using a special device - a disk drive;

- magnetic tapes- a magnetic recording medium, which is a thin flexible tape consisting of a base and a magnetic working layer;

- optical discs- an information carrier in the form of a disk with a hole in the center, information from which is read using a laser. The compact disc was originally created for digital audio storage, but is now widely used as a general-purpose storage device;

- flash memory- a type of solid-state semiconductor non-volatile rewritable memory. Flash memory can be read as many times as you like, but it can only be written to a limited number of times (usually about 10 thousand times). Erasing occurs in sections, so you cannot change one bit or byte without overwriting the entire section.

All media can be divided into:

1. Human readable (documents).

2. Machine-readable (machine) - for intermediate storage of information (disks).

3. Human-machine-readable – combined media for highly specialized purposes (forms with magnetic stripes).

However, the rapid development of computer technology has erased the line between the 1st and 3rd groups - a scanner has appeared that allows you to enter information from documents into the computer’s memory.

All currently available storage media can be divided according to various criteria. First of all, it is necessary to distinguish volatile And non-volatile information storage devices.

Non-volatile drives used for archiving and saving data arrays are divided into:

1. by type of record:

– magnetic storage devices (hard disk, floppy disk, removable disk);

– magnetic-optical systems, also called MO;

– optical, such as CD (Compact Disk, Read Only Memory) or DVD (Digital Versatile Disk);

2. by construction methods:

– a rotating plate or disk (like hard drive, floppy disk, removable disk, CD, DVD or MO);

– tape media various formats;

– drives without moving parts (for example, Flash Card, RAM (Random Access Memory), which have a limited scope due to relatively small amounts of memory compared to the above).

If quick access to information is required, such as when outputting or transmitting data, then media with a rotating disk are used. For archiving performed periodically (Backup), on the contrary, tape media are more preferable. They have large amounts of memory combined with a low price, although at relatively low performance.

Based on their purpose, storage media are divided into three groups:

1. dissemination of information: Pre-recorded media such as CD ROM or DVD-ROM;

2. archiving: media for one-time recording of information, such as CD-R or DVD-R (R (record able) - for recording);

3. backup or data transfer: media with the ability to record information reusably, such as floppy disks, hard disks, MO, CD-RW (RW (rewritable) - rewritable and tapes.