What is a carrier in computer science. Graduation written qualification work. Traditions of antiquity deep
An electronic information carrier is a device for storing, accumulating and transmitting information. For this purpose, a personal computer uses internal storage of information, which is called a hard disk or hard drive. The name "winchester" appeared historically for the first created hard drive, some of the parameters of which turned out to be similar to the caliber of a hunting rifle.
In some cases, the computer user uses additional external devices to store information.
Common external storage media are CDs. They are divided into devices intended only for reading the information already initially recorded on them, devices intended for a single recording of information and further reading, and devices intended for repeated recording, erasing information and reading. The information is written to a CD in the form of files. The burnable CD is inserted into the computer's optical drive. Information on CDs is written using a laser.
Read-only CDs are often some kind of tutorial that was written by the vendor of the software.
films, including educational, audio recordings.
Read-only CDs are designated as follows: CD-ROM (in translation - read-only memory)
Here, for example, on this CD I recorded the archive of my site "Pensioner" for two years, just in case. At the same time, I deleted these files from the computer, as the site developed, many things changed, and it makes no sense to store all the files in the current working folder of the computer, taking up space. This CD can only be read, cannot be overwritten or added to other files. At the same time, you can copy the files from the disc back to your computer if necessary.
This disc has a special layer, which made it possible to print a cover, a disc label with inscriptions and pictures on an inkjet printer. This technology has since become obsolete. Now technologies have been developed with the help of which a cover, a label with inscriptions and pictures can be applied to a disc by simply turning it over in the drive to the other side. To do this, you need to buy a blank CD "with LightScribe support" if you know that your drive supports this technology.
The easiest way is to make an inscription on the disc with a special felt-tip pen, which can be bought at a computer store, instead of making labels.
CDs designed for one-time recording of information and for reading have the letter "R" in the designation,
CD-R or DVD+R or DVD-R
and for repeated writing of the letter "RW":
DVD+RW
DVDs are larger than CDs and are more versatile. On such a universal disc, you can record any files, including audio and video. There are audio CDs - Audio-CDs, intended only for listening in an audio player. This audio recording can also be played on a computer if the playback program is installed on it.
Buying CDs for recording information, you need to keep in mind that they differ in recording speed and volume. It looks like this:
DVD + R - a disc for one-time recording (including video) and for reading.
16x - write speed - medium
Disk capacity - 4.7 GB gigabytes
In a box - 25 blank discs (blanks)
CD-R is a disc for one-time recording (including video) and for reading.
The volume of the disk is 700 MB less, but the speed is higher - 52x, the number of disks in a box is 10 pcs.
DVD + RW - disc for multiple recording, erasing, rewriting and reading.
Write speed 1 to 4x
Disk capacity - 4.7 GB gigabytes
For writing or reading files to a CD it is inserted into the drive of a desktop computer or laptop. By pressing a button, the drive panel slides out, where the disc is neatly placed with the mirror side down.
By pressing the button again, the panel with the disc slides back.
If it is necessary to transfer a large amount of information to external media, creating, for example, a music collection, a video library or a collection of paintings, use external HDs. They are usually small in size and weight, have a large amount of information storage, high write and read speeds, and are durable. Saving a collection of files on a hard drive does not require physical space in the apartment.
While CD collection storage requires special racks and space for them.
In addition, CDs are easily scratched, making the recorded files unreadable. The reliability of storing files on a hard drive is much higher. Information on an external hard drive can be repeatedly frayed and rewritten and, of course, read.
Hard drives come in a variety of shapes and sizes.
They connect to a computer with a USB cable.
There are also external miniature devices for recording and storing information, which are called "flash memory" or "flash drive" or just "flash drive". At the heart of this device is a microcircuit that can save information even when the power is turned off. Flash allows multiple overwriting of information. Modern flash drives of the latest models even surpass CDs in terms of memory capacity.
Flash drives convenient due to their small size and ease of connection not only to a computer, but, for example, even to a TV. Modern digital TVs allow you to play movies recorded on a flash drive in some specific formats. The flash drive is inserted into the "USB" socket on the TV case.
ATTENTION!Here is a very abbreviated text of the abstract. Full version The essay on informatics can be downloaded for free from the link above.
Types of storage media
Information carrier- the physical environment directly storing information. The main carrier of information for a person is his own biological memory (human brain). A person's own memory can be called working memory. Here the word "operational" is synonymous with the word "fast". Learned knowledge is reproduced by a person instantly. We can also call our own memory internal memory, since its carrier - the brain - is inside us.
Information carrier- a strictly defined part of a particular information system, which serves for intermediate storage or transmission of information.
The basis of modern information technology is the computer. When it comes to computers, we can talk about storage media as external storage devices (external memory). These data carriers can be classified according to various features, for example, according to the type of execution, the material from which the carrier is made, etc. One of the options for the classification of information carriers is shown in Fig. 1.1.
The list of storage media in fig. 1.1 is not exhaustive. Some storage media will be discussed in more detail in the following sections.
Tape media
Magnetic tape- a magnetic recording medium, which is a thin flexible tape consisting of a base and a magnetic working layer. The working properties of a magnetic tape are characterized by its sensitivity during recording and signal distortion during recording and playback. The most widely used is a multilayer magnetic tape with a working layer of needle-shaped particles of magnetically hard powders of gamma-iron oxide (y-Fe2O3), chromium dioxide (CrO2) and gamma-iron oxide modified with cobalt, usually oriented in the direction of magnetization during recording.
Disk media
Disk media refer to machine media with direct access. The concept of direct access means that the PC can “access” the track on which the section with the required information begins or where new information needs to be written.
Disk drives are the most diverse:
- Floppy disk drives (FPHD), they are also floppy disks, they are also floppy disks
- Hard disk drives (HDD), they are also hard drives (popularly just "screws")
- Optical CD drives:
- CD-ROM (Compact Disk ROM)
- DVD-ROM
Floppy disk drives
Some time ago, floppy disks were the most popular means of transferring information from computer to computer, since the Internet was a rarity in those days, computer networks too, and CD-readers were very expensive. Floppy disks are still used, but already quite rarely. Mainly for storing various keys (for example, when working with the client-bank system) and for transmitting various reporting information to state supervisory services.
Diskette- a portable magnetic storage medium used for multiple recording and storage of data of relatively small volume. This type of media was especially common in the 1970s and early 2000s. Instead of the term “floppy disk”, the abbreviation GMD is sometimes used - “floppy magnetic disk” (respectively, the device for working with floppy disks is called NGMD - “floppy disk drive”, the slang version is a flop drive, floppy, floppar from the English floppy-disk or in general " cookie"). Usually a floppy disk is a flexible plastic plate coated with a ferromagnetic layer, hence the English name "floppy disk" ("floppy disk"). This plate is placed in a plastic case that protects the magnetic layer from physical damage. The shell is flexible or durable. Floppy disks are read and written using a special device - a disk drive (floppy drive). A floppy disk usually has a write protection feature that allows you to grant read-only access to data. Appearance 3.5” floppy disk is shown in fig. 1.2.
Hard Disk Drives
As hard disk drives, hard disk drives are widely used in PCs.
Term Winchester originated from the slang name for the first 16 kV hard drive (IBM, 1973), which had 30 tracks of 30 sectors, which coincidentally coincided with the 30/30 caliber of the famous Winchester hunting rifle.
Optical drives
Compact disc("CD", "Shape CD", "CD-ROM", "CD ROM") - an optical storage medium in the form of a disk with a hole in the center, information from which is read using a laser. The CD was originally created for digital audio storage (called Audio-CD), but is now widely used as a general purpose storage device (called CD-ROM). Audio CDs are formatted differently from data CDs, and CD players can usually only play them (you can, of course, read both types of CDs on a computer). There are discs containing both audio information and data - you can listen to them on a CD player and read them on a computer.
Optical discs usually have a polycarbonate or glass heat-treated base. The working layer of optical disks is made in the form of the thinnest films of fusible metals (tellurium) or alloys (tellurium-selenium, tellurium-carbon, tellurium-selenium-lead, etc.), organic dyes. The information surface of optical discs is covered with a millimeter layer of durable transparent plastic (polycarbonate). In the process of recording and playback on optical discs, the role of the signal converter is performed by a laser beam focused on the working layer of the disc into a spot with a diameter of about 1 μm. As the disk rotates, the laser beam follows along the disk track, the width of which is also close to 1 μm. The ability to focus the beam into a small spot makes it possible to form marks on the disk with an area of 1–3 μm. Lasers (argon, helium-cadmium, etc.) are used as a light source. As a result, the recording density is several orders of magnitude higher than the limit provided by the magnetic recording method. The information capacity of an optical disk reaches 1 GB (with a disk diameter of 130 mm) and 2-4 GB (with a diameter of 300 mm).
Widespread use as a carrier of information has also received magneto-optical CDs type RW (Re Writeble). Information is recorded on them by a magnetic head with the simultaneous use of a laser beam. The laser beam heats up a point on the disk, and the electromagnet changes the magnetic orientation of that point. Reading is performed by a laser beam of lower power.
In the second half of the 1990s, new, very promising carriers of documented information appeared - digital universal video discs DVD (Digital Versatile Disk) of the DVD-ROM, DVD-RAM, DVD-R type with a large capacity (up to 17 GB).
According to the technology of application, optical, magneto-optical and digital CDs are divided into 3 main classes:
- Disks with permanent (non-erasable) information (CD-ROM). These are plastic CDs with a diameter of 4.72 inches and a thickness of 0.05 inches. They are made using an original glass disc, on which a photo-recording layer is applied. In this layer, the laser recording system forms a system of pits (marks in the form of microscopic depressions), which is then transferred to replicated copy discs. Reading information is also carried out by a laser beam in the optical drive of a personal computer. CD-ROMs typically have a capacity of 650 MB and are used for recording digital audio programs, software for computers, etc.;
- Discs that allow one-time recording and multiple playback of signals without the possibility of erasing them (CD-R; CD-WORM - Write-Once, Read-Many - recorded once, counted many times). They are used in electronic archives and data banks, in external computer drives. They are a base made of a transparent material on which a working layer is applied;
- Reversible optical discs that allow multiple recording, playback and erasing of signals (CD-RW; CD-E). These are the most versatile discs that can replace magnetic media in almost all areas of application. They are similar to write-once discs, but contain an operating layer in which the physical write processes are reversible. The manufacturing technology of such discs is more complicated, so they are more expensive than record-once discs.
Electronic media
Generally speaking, all the carriers considered earlier are also indirectly related to electronics. However, there is a type of media where information is stored not on magnetic / optical disks, but in memory chips. These microcircuits are made using FLASH technology, so such devices are sometimes called FLASH disks (popularly just a "flash drive"). The microcircuit, as you might guess, is not a disk. However, operating systems define storage media with FLASH memory as a disk (for user convenience), so the name "disk" has the right to exist.
Flash memory (eng. Flash-Memory) - a kind of solid-state semiconductor non-volatile rewritable memory. Flash memory can be read as many times as desired, but it can only be written to a limited number of times (usually about 10,000 times). Despite the fact that there is such a limit, 10 thousand rewrite cycles is much more than a floppy disk or CD-RW can withstand. Erasure occurs in sections, so you cannot change one bit or byte without rewriting the entire section (this limitation applies to the most popular type of flash memory today - NAND). The advantage of flash memory over conventional memory is its non-volatility - when the power is turned off, the contents of the memory are saved. The advantage of flash memory over hard drives, CD-ROMs, DVDs is that there are no moving parts. Therefore, flash memory is more compact, cheaper (including the cost of read-write devices), and provides faster access.
Data storage
Data storage It is a way of disseminating information in space and time. The method of storing information depends on its carrier (a book is a library, a picture is a museum, a photograph is an album). This process is as ancient as the life of human civilization. Already in antiquity, man was faced with the need to store information: notches on trees so as not to get lost while hunting; counting objects with the help of pebbles, knots; images of animals and episodes of hunting on the walls of caves.
The computer is designed for compact storage of information with the ability to quickly access it.
Information system- this is a repository of information, equipped with procedures for entering, searching and placing and issuing information. The presence of such procedures is the main feature of information systems that distinguish them from simple accumulations of information materials.
From information to data
People have different approaches to storing information. It all depends on how much it is and how long it needs to be stored. If there is little information, it can be remembered in the mind. It is not difficult to remember the name of your friend and his last name. And if you need to remember his phone number and home address, we use a notebook. When information is stored (stored) it is called data.
Data in a computer has a different purpose. Some of them are needed only for a short period, others must be stored for a long time. Generally speaking, there are quite a few "tricky" devices in the computer that are designed to store information. For example, processor registers, register cache, etc. But most of the "mere mortals" did not even hear such "terrible" words. Therefore, we will confine ourselves to consideration of random access memory (RAM) and permanent memory, which includes the information carriers we have already considered.
Computer RAM
As already mentioned, the computer also has several means for storing information. Most fast way to remember data is to write them into electronic microcircuits. This memory is called RAM. RAM is made up of cells. Each cell can store one byte of data.
Each cell has its own address. We can assume that this is like a cell number, so such cells are also called address cells. When the computer sends data to be stored in RAM, it remembers the addresses where this data is placed. Referring to the address cell, the computer finds a byte of data in it.
RAM regeneration
An address cell in RAM stores one byte, and since a byte is made up of eight bits, there are eight bit cells in it. Each bit cell of the RAM chip stores an electrical charge.
Charges cannot be stored in cells for a long time - they "drain". In just a few tenths of a second, the charge in the cell decreases so much that data is lost.
Disk memory
Data carriers are used for permanent data storage (see section "Types of information carriers"). Compact discs and floppy disks are relatively slow, so most of the information that needs constant access is stored on the hard drive. All information on a disk is stored as files. There is a file system to control access to information. There are several types of file systems.
Data structure on disk
In order for the data to be not only written to the hard disk, and then also read, you need to know exactly what was written and where. All data must have an address. Each book in the library has its own hall, rack, shelf and inventory number - this is, as it were, its address. The book can be found at this address. All data that is written to the hard disk must also have an address, otherwise they cannot be found.
File systems
It is worth noting that the structure of data on a disk depends on the type of file system. All file systems are made up of the structures needed to store and manage data. These structures typically include the operating system boot record, directories, and files. The file system also performs three main functions:
- Keeping busy and free space
- Support for directory and file names
- Keeping track of the physical location of each file on disk.
- FAT (File Allocation Table)
- FAT32 (File Allocation Table 32)
- NTFS (New Technology File System)
- HPFS (High Performance File System)
- NetWare File System
- Linux Ext2 and Linux Swap
FAT
The FAT file system is used by DOS, Windows 3.x and Windows 95. The FAT file system is also available in Windows 98/Me/NT/2000 and OS/2.
The FAT file system is implemented using the File Allocation Table (FAT - File Allocation Table) and clusters. FAT is the heart of the file system. For security, FAT has a duplicate to protect its data from accidental erasure or malfunction. A cluster is the smallest unit of the FAT system for storing data. One cluster consists of a fixed number of disk sectors. The FAT records which clusters are in use, which are free, and where the files are located within the clusters.
FAT-32
FAT32 is a file system that can be used by Windows 95 OEM Service Release 2 (version 4.00.950B), Windows 98, Windows Me, and Windows 2000. However, DOS, Windows 3.x, Windows NT 3.51/4.0, earlier versions of Windows 95 and OS/2 do not recognize FAT32 and cannot load or use files on a FAT32 drive or partition.
FAT32 is an evolution of the FAT file system. It is based on a 32-bit file allocation table, which is faster than the 16-bit tables used by the FAT system. As a result, FAT32 supports much larger disks or partitions (up to 2 TB).
NTFS
NTFS ( New technology File System) is only available on Windows NT/2000. NTFS is not recommended for drives smaller than 400 MB because it requires a lot of space for system structures.
The central structure of the NTFS file system is the MFT (Master File Table). NTFS keeps many copies of the critical part of the table to protect against malfunctions and data loss.
HPFS
HPFS (High Performance File System) is a privileged file system for OS/2 which is also supported by older Windows versions NT.
Unlike FAT file systems, HPFS sorts its directories based on filenames. HPFS also uses a more efficient directory structure. As a result, file access is often faster and space is used more efficiently than with the FAT file system.
HPFS distributes file data in sectors, not in clusters. To store a track that has sectors or is not in use, HPFS organizes the disk or partition into 8 MB groups. This grouping improves performance because the read/write heads don't have to return to track zero every time the OS needs to access information about the available space or the location of a needed file.
NetWare File System
The Novell NetWare operating system uses the NetWare file system, which was designed specifically for use by NetWare services.
Linux Ext2 and Linux Swap
The Linux Ext2 and Linux file systems were developed for the Linux OS (UNIX version for free distribution). The Linux Ext2 file system supports a disk or partition with a maximum size of 4 TB.
Directories and file path
Consider, for example, the structure of the disk space of the FAT system, as the simplest.
The disk space information structure is a user-oriented external representation of disk space and is defined by such elements as volume (logical disk), directory (folder, directory) and file. These elements are used when the user communicates with the operating system. Communication is carried out using commands that perform file and directory access operations.
Sources of information
- Informatics: Textbook. - 3rd revision. ed. / Ed. N.V. Makarova. - M.: Finance and statistics, 2002. - 768 p.: ill.
- Wolf V.K. Study of the functional structure of the memory of a personal computer. Laboratory practice. Tutorial. Kurgan Publishing House state university, 2004 - 72 p.
Viewed: 13446
0
The accumulation of knowledge is the foundation of any civilization. But human memory is imperfect and unable to contain all the knowledge and experience that pass from generation to generation. Therefore, since ancient times, people have used a wide variety of information carriers, from stone and animal skins to high-quality paper. At the same time, despite the improvement in the types of media, the very principle of recording and the data structure have not changed much over several millennia.
A qualitative leap occurred only when a person needed to teach a machine to understand the recorded information.
More than two hundred years ago, in 1808, the French inventor Joseph Marie Jacquard created a machine for the production of fabrics with complex patterns. The uniqueness of this device lay in the fact that the first software-controlled machine was actually designed and built. The sequence of actions of the machine when creating a pattern was recorded on special cardboard punched cards in the form of holes punched in a certain order.
It is unlikely that Jacquard imagined how bright the future was in store for his invention. Not to the machine, but to the principle of recording information in the form of a binary code, which became the basis of the alphabet of all computers.
Later, Jaccard's ideas were used in automatic telegraphs, where the sequence of Morse code signals was recorded on punched tapes, in Charles Babbage's analytical engine, which became the prototype of modern computers, in Herman Hollerith's statistical tabulator, and, of course, in the first computers of the twentieth century. Due to their simplicity, various versions of punched cards and punched tapes are widely used in computer technology and program-controlled machine tools. Such information carriers were used until the mid-80s, when they were finally replaced by magnetic media.
Punched cards and punched tapes
Years of life: 1808–1988
Memory size: up to 100 KB
Easy to manufacture, can be used in the most low-tech devices
– Low recording density, low read/write speed, low reliability, impossibility to overwrite information
NATURAL MAGNETISM
Punched cards and punched tapes, for all their advantages and rich history, had two fatal flaws. The first is a very low information capacity. Only 80 characters or about 100 bytes could fit on a standard punched card; more than ten thousand punched cards would be needed to store one megabyte of information. The second is a low reading speed: the input device could swallow a maximum of 1000 punched cards per minute, that is, only 1.6 kilobytes per second. The third is the impossibility of overwriting. One extra hole - and the storage medium becomes unusable, like all the information on it.
In the middle of the 20th century, a new principle of information storage was proposed, based on the phenomenon of residual magnetization of some materials. Briefly, the principle of operation is as follows: the surface of the carrier is made of a ferromagnet, after exposure to which a magnetic field retains the residual magnetization of the substance on the material. It is then subsequently registered by reading devices.
The first signs of this technology were magnetic cards, which coincided in size and function with conventional punched cards. However, they were not widely used and were soon superseded by more capacious and reliable tape drives.
These storage devices have been in active use in mainframes since the 1950s. Initially, they were huge cabinets with a tape drive mechanism and reels of tape, on which information was recorded. Despite more than a respectable age, the technology has not died and is still used today in the form of streamers. These are storage devices made in the form of a compact magnetic tape cartridge designed for backing up information. The key to their success is a large capacity, up to 4 TB! But for any other tasks, they are practically unsuitable due to the extremely low data access speed. The reason is that all information is recorded on magnetic tape, therefore, in order to gain access to any file, it is necessary to rewind the tape to the desired section.
A fundamentally different approach to writing data is used in floppy disks. This is a portable storage device, which is a disk covered with a ferromagnetic layer and enclosed in a plastic cartridge. Floppy disks appeared as a response to the need of users for pocket storage media. However, the word "pocket" for early samples is not entirely suitable. There are several formats of floppy disks depending on the diameter of the magnetic disk inside. The first floppy disks, which appeared in 1971, were 8-inch, that is, with a disk diameter of 203 mm. So you could only put them in a folder for papers. The amount of recorded information was as much as 80 kilobytes. However, two years later this figure increased to 256 kilobytes, and by 1975 - up to 1000 KB! It was time for a format change, and in 1976, 5-inch (133 mm) floppy disks appeared. Their volume was originally only 110 Kb. But technology improved, and already in 1984, “high-density recording” floppy disks with a volume of 1.2 MB appeared. It was the "swan song" of the format. In the same 1984, 3.5-inch floppy disks appeared, which can already rightly be called pocket ones. According to legend, the size of 3.5 inches (88 mm) was chosen on the principle of placing a floppy disk in the breast pocket of a shirt. The volume of this medium was originally 720 KB, but quickly grew to the classic 1.44 MB. Later, in 1991, 3.5-inch extended density Extended Density floppy disks appeared, containing 2.88 MB. But they were not widely used, because a special drive was required to work with them.
A further development of this technology was the famous (in some places infamous) Zip. In 1994, Iomega launched a record-breaking 100 MB hard drive on the market at the time. The principle of operation of the Iomega Zip is the same as that of conventional floppy disks, but thanks to the high recording density, the manufacturer has also managed to achieve a record storage capacity. However, Zips turned out to be rather unreliable and expensive, so they could not occupy the niche of three-inch floppy disks, and were subsequently completely replaced by more advanced storage devices.
floppy disks
Years of life: 1971 - to this day
Memory capacity: up to 2.88 MB
Compact size, low cost
– Low reliability, vulnerable case, low recording density
Magnetic tape
Years of life: 1952 - to this day
Memory capacity: up to 4 TB
Rewritable, wide operating temperature range (from -30 to +80 degrees), low media cost
– Low recording density, the impossibility of instant access to the desired memory cell, low reliability
Magnetic tape drives were huge cabinets with a tape drive mechanism and reels of tape, on which information was recorded.
HARD RULES
The hard drive, Hard Disk Drive, is the main storage device in almost all modern computers.
In general, the principle of operation of both existing and developed hard drives is based on the phenomenon of residual magnetization of materials. But there are some nuances here. The direct storage medium in a hard drive is a block of one or more round plates coated with a ferromagnet. The read head, moving above the surface of disks rotating at high speed, writes information by magnetizing billions of tiny areas (domains) or reads data by registering the residual magnetic field.
The smallest cell of information in this case is one domain, which can be either a logical zero or one. Thus, the smaller the size of one domain, the more data can be cram into one hard drive.
The first HDD appeared in 1956. The device consisted of 50 disks with a diameter of 600 mm each, rotating at a speed of 1200 rpm. The dimensions of this HDD were comparable to a modern two-chamber refrigerator, and the capacity was as much as 5 MB.
Since then, hard disk storage density has increased more than 60 million times. Over the past decade, manufacturing companies have been steadily doubling the capacity of disks every year, but now this process has stopped: the maximum possible recording density has been reached for the materials and, most importantly, technologies currently used.
The most common now is the so-called parallel recording. Its meaning is that the ferromagnet, to which the data is transferred, consists of many atoms. A certain number of such atoms together make up a domain - the minimum cell of information. Reducing the size of the domain is possible only up to a certain limit, since the atoms of a ferromagnet interact with each other and at the junction of logical zero and unity (areas with oppositely directed magnetic moments) may lose stability. Therefore, a certain buffer zone is required to ensure the reliability of information storage.
In parallel recording, the magnetic particles are placed in such a way that the magnetic directivity vector is parallel to the disk plane. With perpendicular recording, the magnetic particles are perpendicular to the surface of the disc.
In parallel recording, the magnetic particles are placed in such a way that the magnetic directivity vector is parallel to the disk plane. From a technology point of view, this is the simplest solution. At the same time, with such a record, the strength of interaction between domains is the highest, so a large buffer zone is needed, and, consequently, a larger size of the domains themselves. So the maximum density for parallel recording is about 23 Gbit / cm2, and this height has already been practically taken.
A further increase in the capacity of hard drives is possible by increasing the number of working plates in the device, but this method is a dead end. The sizes of modern HDDs are standardized, and the number of disks used in them is limited by design requirements.
There is another way - using a new record type. Since 2005, hard drives using the perpendicular recording method can be found on sale. With such a recording, the magnetic particles are located perpendicular to the surface of the disk. Due to this, the domains weakly interact with each other, since their magnetization vectors are located in parallel planes. This allows you to seriously increase the density of information - the practical ceiling is estimated at 60-75 Gbit / cm2, i.e. 3 times more than for parallel recording.
But the most promising technology is HAMR. This is the so-called thermal magnetic recording method. In fact, HAMR is a further development of the perpendicular recording technology, with the only difference being that at the moment of recording, the desired domain is subjected to short-term (about a picosecond) point heating by a laser beam. Due to this, the head can magnetize very small areas of the disc. There are no HAMR-HDDs on the open market yet, but prototypes demonstrate a record recording density of 150 Gb / cm2. In the future, according to representatives of Seagate Technology, the density will be increased to 7.75 Tb / cm2, which is almost 350 times higher than the maximum density for parallel recording.
HDD with parallel recording
Years of life: 1956 - to this day
Memory capacity: up to 2 TB at the moment
The ability to instantly jump to the desired cell of information, a good combination of price / quality
– Insufficient recording density today, obsolete technology
HDD with perpendicular recording
Years of life: 2005 - the near future
Memory capacity: up to 2.5 TB at the moment
High recording density
– More complex manufacturing technology, high price, low reliability of new capacious models
HAMR-HDD
Years of life: 2010 - the near future
Memory capacity: time will tell
Even higher recording density
– Particularly complex manufacturing technology and correspondingly high price
OPTICS ON THE MARCH
Despite the constant increase in the capacity of stationary hard drives, there is a need for a compact and mobile storage medium. To date, CD and DVD are leading in this area. In fact, any information - music, software, films, encyclopedias or cliparts - can be bought on these media.
The first representative of this technology is LD (Laser Disc), developed back in 1969. These discs were intended primarily for home theaters, but despite a number of advantages over VHS and Betamax video cassettes, they were not widely used. The next representative of optical media turned out to be much more successful. It was the well-known compact disc (CD, Compact Disc). It was developed in 1979 and was originally intended for recording high quality music. But in 1987, through the efforts of Microsoft and Apple, CDs began to be used in personal computers. So users got at their disposal a compact and reliable high-capacity storage medium: the standard volume of 650 MB seemed inexhaustible for the late 80s.
The CD hasn't changed much in the last 20 years. The carrier is a kind of "sandwich", consisting of three layers. The basis of the CD is a polycarbonate substrate, onto which the thinnest layer of metal (aluminum, silver, gold) is sprayed. On this layer, in fact, the recording is made. The metal coating is covered with a layer of protective varnish, and all sorts of pictures, logos, names and other identification marks are already applied to it.
Optical discs work by changing the intensity of reflected light. On an ordinary CD, all information is recorded on one spiral track, which is a sequence of depressions, pits (from the English pit - “depression”). Between the recesses there are areas with a smooth reflective layer, lands (from the English land - “earth, surface”). Data is read using a laser beam focused into a spot of light about 1.2 µm in diameter. If the laser hits the land, a special photodiode registers the reflected beam and fixes the logical unit. If the laser hits the pit, the beam scatters, the intensity of the reflected light decreases and the device fixes a logical zero.
The first laserdiscs were read-only. They were manufactured strictly in the factory and the pits on them were applied by stamping directly onto a bare polycarbonate substrate, after which the discs were covered with a reflective layer and a protective varnish.
But already in 1988, CD-R (Compact Disc-Recordable) technology appeared. Disks made using this technology could be used for a single recording of information using a special writing drive. To do this, another layer of thin organic dye was placed between the polycarbonate and the reflective layer. When heated to a certain temperature, the dye was destroyed and darkened. During the recording process, the drive, controlling the power of the laser, applied a sequence of dark dots to the disk, which, when read, were perceived as pits.
Ten years later, in 1997, CD-RW (Compact Disc-Rewritable) was created - a rewritable CD. Unlike CD-R, here a special alloy was used as a recording layer, capable of changing from a crystalline state to an amorphous state and vice versa under the influence of a laser beam.
LD
Years of life: 1972–2000
Memory capacity: 680 MB
First commercial optical storage media
- It was used only as a video and audio carrier and was not inferior in size to vinyl discs, which created certain inconveniences
CD
Years of life: 1982 - to this day
Memory capacity: 700 MB
Compactness, relative reliability, low cost
– Low, by modern standards, capacity, obsolete technology
NEW GENERATION DIGES
In the mid-90s, when the CD era was in full swing, astute manufacturers were already working to improve optical discs. In 1996, the first DVD (Digital Versatile Disc) with a capacity of 4.7 GB appeared on sale. New storage media exploited the same principle as CDs, only a laser with a shorter wavelength was used for reading - 650 nm versus 780 nm for CDs. This seemingly simple change made it possible to reduce the size of the light spot, and, consequently, the minimum size of the information cell. Therefore, the DVD disc was able to hold 6.5 times more useful information than the CD.
In 1997, the first recordable DVD-Rs also went on sale, also exploiting the technology proven on CD-Rs. However, these innovations reached the masses only a few years later, since the first DVD-R burner cost about $17,000, and discs - $50 apiece.
Today DVD has become an integral part of the computer industry. But he didn't have long to live. Rapid advances in high technology and the growing needs of users require new, higher-capacity media.
The first signs were double-layer DVDs. In them, information is recorded at two different levels, the usual lower and translucent upper. By changing the focus of the laser, it is possible to read data from both layers in turn. These DVDs hold 8.5 GB of information. Then came double-layer double-sided DVDs. These discs have both working sides and contain two layers of information. Storage capacity has grown to 17 GB.
On this indicator, the ceiling of DVD technology was reached. Further increase in the number of layers seems to be an unnecessarily difficult problem, the thickness of the disk is still limited, so it is very difficult to cram something into it. In addition, even with a two-layer system, there were many complaints about the quality of reading information, and it's scary to think how many errors hypothetical three-layer DVDs can produce.
Manufacturers solved (temporarily, of course) the problem of increasing capacity by creating a new format. Rather, two at once: HD-DVD and Blu-ray. Both technologies use a blue laser with a wavelength of 405 nm. As we have already said, reducing the wavelength also makes it possible to reduce the minimum size of a memory cell and, consequently, increase the recording density. The appearance of two new types of discs at once provoked the so-called "format war", which lasted about two years. Ultimately, despite certain advantages, HD-DVD lost this battle. According to many experts, the extremely strong support of the Blu-ray format by American film studios played a major role in this.
The Blue Beam is currently the only high capacity optical storage medium available commercially. Drives 23, 25, 27 and 33 GB. There are also two-layer samples with a capacity of 46, 50, 54 and 66 GB.
DVD
Years of life: 1996 - to this day
Memory capacity: up to 17.1 GB
The most popular storage media: the vast majority of music, movies and various software is distributed on DVD
- obsolete technology
HD DVD
Years of life: 2004–2008
Memory capacity: up to 30 GB
High capacity plus relatively low price due to cheaper production
– Lack of support from the American film industry.
Blu-ray
Years of life: 2006 - to this day
Memory capacity: up to 66 GB
High storage capacity, support for Hollywood monsters
– High cost of drives and carriers, since fundamentally new equipment is required for production
GIGABYTE RACE
The market for disk drives is a very tasty morsel. Therefore, in the near future we should expect, if not the displacement of Blu-ray from the leading positions, then a new war of formats.
A unique feature of the holographic method is the ability to record a huge amount of information almost at one point. This gives manufacturers reason to assert that the already reached ceiling of 3.6 TB is far from the limit.
There are a number of technologies that claim users' wallets. For example, HD VMD (High Density - Versatile Multilayer Disc). This format was introduced in 2006 by a little-known British company, New Medium Enterprises. Here the manufacturer took the path of increasing the number of recorded layers in one disc - there are already 20 of them. Thanks to this, the maximum capacity of HD VMD today is 100 GB. In general, it is unlikely that the small New Medium Enterprises will be able to seriously oust the multimedia giants. But thanks to the declared low cost of disks and drives for them (due to the use of a cheaper red laser with a wavelength of 650 nm), the British can theoretically count on a certain popularity of their products. If she, of course, even gets to the market.
Another contender is the Ultra Density Optical (UDO) format. Development began in June 2000, and now it is already a completely finished device available on the market. Here, a bet was made on increasing the accuracy of beam focusing. With a laser wavelength of 650 nm, a UDO disk can hold 30 to 60 GB of information. There are also media using a blue laser (405 nm), in which case the maximum UDO capacity is 500 GB. But you have to pay for everything: the increase in laser accuracy has led to a serious rise in the cost of drives. The media themselves are produced in the form of a 5.35-inch cartridge with a disk inside (for protection from external influences) and are sold at a price of $60-70. To date, UDO technology is used mainly by large companies for archiving information and creating backups data.
HD VMD (High Density - Versatile Multilayer Disc)
Years of life: 2006 - the near future
Memory capacity: up to 100 GB
High capacity, relatively low cost
– Lack of support from major market players, which will most likely cause the death of the format
UDO (Ultra Density Optical)
Years of life: 2000 - to this day
Memory capacity: up to 120 GB
good capacity
– High cost of drives and media, focusing on a highly specialized market for data archiving devices
HOLOGRAPHY IS BURNING
Despite the abundance of optical disc formats, there is already a technology that will surely leave all competitors behind in the future. This is a holographic recording. The benefits of this technology and its potential are enormous. First, if in conventional optical discs information is written to a layer using individual cells of information, then in holographic memory data is distributed over the entire volume of the carrier, and several million cells can be written in one cycle, due to which the speed of writing and reading increases dramatically. Secondly, due to the distribution of information in three dimensions, the maximum storage capacity reaches really sky-high heights.
Work in this direction began about ten years ago, and today there is a quite intelligible technology, according to which 1.6 TB of information can be written on a standard-sized disk. At the same time, the read speed is 120 Mb / s.
The operating principle of the holographic recording is implemented as follows. The laser beam is divided by a translucent mirror into two streams having the same wavelength and polarization. A spatial light modulator, which is a flat stencil, converts digital information into a sequence of transparent and opaque cells that correspond to a logical one and zero. The signal beam, having passed through this grating and having received a portion of information, is projected onto the carrier. The second beam - the reference one - falls at an angle into the same region of the disk. At the same time, at the points where the reference and signal beams intersect, the wave amplitudes are added (interference), as a result of which the beams jointly burn through the photosensitive layer, fixing the information on the carrier. Thus, in one cycle, all information is recorded at once, which can be mastered by the resolution of the light modulator. Today it is about a million bits at a time.
The data is read using a reference beam, which, passing through the body of the carrier, projects the recorded hologram onto the photosensitive layer, and that layer already converts the "grid" falling on it into a sequence of zeros and ones.
A unique feature of the holographic method is the ability to record a huge amount of information almost at one point. This makes it possible to efficiently use the entire volume of the carrier. The practical capacity ceiling of holographic disks is not exactly known, but the manufacturers claim that the 3.6 TB ceiling they have already reached is far from the limit.
Holographic discs
Years of life: the near future
Memory capacity: up to 1 TB
Very, well, very high capacity while maintaining compact media dimensions
- Time will tell
HDD + LASER
In 2006, Daniel Stanciu, who was working on his doctoral dissertation, and Dr. Frederic Hansteen discovered a way to change the polarity of a magnet using light radiation. I must say that earlier it was considered impossible in principle. Not surprisingly, Daniel Stansiu successfully defended his doctoral dissertation, and the technology itself, which received a rather strange name - purely optical magnetization inversion - has already found potential applications.
So, with the help of a laser beam, it is possible to magnetize the domains of hard drives, that is, to perform the same work that the writing head is currently working on, but much faster. The write speed on a conventional hard drive does not exceed 100–150 Mbps. In the prototype "laser" hard drive, this figure today is 1 Tb / s or 1,000,000 Mb / s. Scientists are sure that this is not the limit - they expect to increase the recording speed to 100 Tbps. In addition, with the help of a laser, it is possible to significantly increase the density of recorded information, which, theoretically, makes laser hard disks one of the most promising technologies storage and recording of data.
But today there is no information about the device of the reading head for such HDDs. With a laser, you can only record information. It cannot fix the magnetization of domains. Therefore, for reading it will be necessary to use standard magnetic heads. In addition, do not forget that both the write speed and the read speed of the HDD directly depend on the rotation speed of the disks. So the optimistic statements of scientists look somewhat strange. To achieve 1 Tbps, you need to spin the disk to such speeds that it is likely to shatter into pieces under the influence of monstrous centrifugal force or even burn out from friction with air. Of course, the use of a certain optical beam redirection system allows you to completely abandon the rotation of the disk during recording. But reading is still done by a magnetic head, which is vital to slide over the surface of the disk.
In a word, the prospects for the technology of purely optical magnetization inversion, although attractive, are very vague.
Laser HDD
Years of life: the near future
Memory capacity: time will tell
High density and speed of information recording, in the future - the possibility of reducing the number of moving parts of the disk
Too many questions that no one answers
BRIGHT FUTURE?
Disks are disks, but a compact, capacious and, most importantly, easy-to-use storage device is vital for an ordinary user. Today, flash drives are used for this purpose, or, scientifically speaking, USB Flash Drive. The flash memory of this device is an array of transistors (cells), each of which can store one bit of information.
This carrier has many advantages. Flash drives, unlike their predecessors, do not have moving parts. They are compact, reliable and capable of storing quite substantial amounts of information, and manufacturers are working tirelessly to increase their capacity. There are flash drives that hold 8, 12 and even 64 GB of data. True, such toys compete in price with a first-class computer in the all-inclusive package, but this is a temporary phenomenon. Until recently, a 1 GB flash drive was asking for a fortune, but now it is available to every student receiving a scholarship.
Another benefit of a flash drive is ease of use. The flash drive is connected to the computer's USB port, operating system detects a new device, and the contents of the flash drive are displayed as an additional disk in the system. Accordingly, working with files is no different from working with a conventional hard drive. None required additional programs, you do not need to puzzle over the compatibility of devices and formats, peer at the manufacturer of the device, wondering whether it will fit your computer or not.
Flash memory is reliable, not afraid of vibrations, does not make noise, consumes little energy, the speed of information exchange is close to that of standard hard drives. Flash memory, due to the absence of moving parts, has high reliability, is not afraid of vibrations, does not make noise and consumes little energy. The benefits are obvious.
The reading of data in the holographic method occurs with the help of a reference beam, which, passing through the body of the carrier, projects the recorded hologram onto the photosensitive layer, and the latter transforms the "grid" incident on it into a sequence of zeros and ones.
Today, portable computers are already being produced, in which instead of the usual HDDs, SSD (Solid State Drive) chips are installed, the so-called solid-state drives based on flash memory. Fundamentally, such storage devices are no different from ordinary flash drives. Notebooks with SSD, due to low power consumption, are able to work almost twice as long as those equipped with conventional hard drives. However, flash memory also has its serious drawbacks. First, the speed of data exchange in the SSD is still significantly behind the performance of hard drives. But this problem will be solved in the very near future. The second disadvantage is much more serious. Flash memory by design can withstand a limited number of erase and write cycles - about 100,000 cycles. Without going into technical details, we can make a diagnosis: the process of writing and erasing data leads to physical wear of memory cells at the electronic level. However, taking a calculator in hand and doing the simplest calculations, the user brightens his face and happily declares that even if every day ten times a day the flash drive is completely refilled, 100,000 cycles will be enough for 27 years! But in practice, flash memory (for example, a memory card in a camera), intensively used every day, can fail after two or three years of operation.
Flash memory
Years of life: 1989 - to this day
Memory capacity: up to 80 GB
Easy to use, low power consumption, reliable
– Limited number of write/erase cycles
Today, progress in the field computer technology in general and storage devices in particular is rapidly changing the world.
Looking into the future is a thankless task, but it is safe to say that if manufacturers cannot overcome the only serious drawback of flash memory, fail to achieve the HDD capacity required by users, or create a simple and reliable holographic disk, they will inevitably come up with another way to store information.
Cheap, reliable, compact, fast.
An information carrier (information carrier) is any material object used by a person to store information. This can be, for example, stone, wood, paper, metal, plastics, silicon (and other types of semiconductors), tape with a magnetized layer (in reels and cassettes), photographic material, plastics with special properties (for example, in optical discs), and etc., etc.
An information carrier can be any object from which reading (reading) of the information available on it is possible.
Information carriers are used for:
- records;
- storage;
- reading;
- transmission (dissemination) of information.
Often, the information carrier itself is placed in a protective shell, which increases its safety and, accordingly, the reliability of storing information (for example, paper sheets are placed in a cover, a memory chip is placed in plastic (smart card), a magnetic tape is placed in a case, etc.) .
Electronic media include media for single or multiple recording (usually digital) by electrical means:
- optical discs (CD-ROM, DVD-ROM, Blu-ray Disc);
- semiconductor (flash memory, floppy disks, etc.);
- CD-disks (CD - Compact Disk, CD), which can contain up to 700 MB of information;
- DVD-disks (DVD - Digital Versatile Disk, digital versatile disk), which have a significantly larger information capacity (4.7 GB), since the optical tracks on them are thinner and more densely placed;
- HR DVD and Blu-ray discs with 3 to 5 times the storage capacity of DVDs using a 405 nanometer blue laser.
Electronic media have significant advantages over paper media (paper sheets, newspapers, magazines):
- by volume (size) of stored information;
- by unit cost of storage;
- on the economy and efficiency of providing up-to-date (intended for short-term storage) information;
- if possible, provide information in a form convenient for the consumer (formatting, sorting).
There are also disadvantages:
- fragility of reading devices;
- weight (mass) (in some cases);
- dependence on power sources;
- the need for a reader / writer for each type and format of media.
A hard disk drive or HDD (English hard (magnetic) disk drive, HDD, HMDD), a hard disk is a storage device (information storage device) based on the principle of magnetic recording. It is the main storage medium in most computers.
Unlike a "flexible" disk (floppy disk), information in a hard drive is recorded on hard plates coated with a layer of ferromagnetic material - magnetic disks. The HDD uses one or more platters on the same axis. Reading heads in the operating mode do not touch the surface of the plates due to the layer of air flow formed near the surface during rapid rotation. The distance between the head and the disk is several nanometers (in modern disks about 10 nm), and the absence of mechanical contact ensures long term device services. In the absence of disk rotation, the heads are at the spindle or outside the disk in a safe ("parking") zone, where their abnormal contact with the surface of the disks is excluded.
Also, unlike a floppy disk, a storage medium is usually combined with a drive, a drive, and an electronics unit. Such hard drives are often used as non-removable storage media.
Optical (laser) disks are currently the most popular storage media. They use the optical principle of recording and reading information using a laser beam.
DVDs can be double-layered (capacity 8.5 GB), while both layers have a reflective surface that carries information. In addition, the information capacity of DVD discs can be further doubled (up to 17 GB) since information can be recorded on both sides.
Optical drives are divided into three types:
- without the ability to write - CD-ROM and DVD-ROM (ROM - Read Only Memory, read-only memory). CD-ROMs and DVD-ROMs store information that was written to them during the manufacturing process. Sign up for them new information impossible;
- with a single record and multiple reading - CD-R and DVD ± R (R - recordable, recordable). On CD-R and DVD±R discs, information can be recorded, but only once;
- rewritable - CD-RW and DVD ± RW (RW - Rewritable, rewritable). Information on CD-RW and DVD±RW discs can be written and erased multiple times.
The main characteristics of optical drives:
- disc capacity (CD - up to 700 MB, DVD - up to 17 GB)
- the speed of data transfer from the carrier to the RAM - measured in fractions of a multiple of the speed of 150 Kb / s for CD drives;
- access time - the time required to search for information on the disk, measured in milliseconds (for CD 80-400 ms).
Currently, 52x-speed CD drives are widely used - up to 7.8 MB / s. CD-RW discs are recorded at a lower speed (for example, 32x). Therefore, CD drives are marked with three numbers "read speed x CD-R write speed x CD-RW write speed" (for example, "52x52x32").
DVD drives are also labeled with three numbers (for example, "16x8x6").
If the rules of storage (storage in cases in a vertical position) and operation (without scratches and dirt) are observed, optical media can retain information for decades.
Flash memory refers to electrically reprogrammable memory (EEPROM) semiconductors. Due to technical solutions, low cost, large volume, low power consumption, high speed, compactness and mechanical strength, flash memory is built into digital portable devices and storage media. The main advantage of this device is that it is non-volatile and does not need electricity to store data. All information stored in flash memory can be read an infinite number of times, but the number of complete write cycles, unfortunately, is limited.
Flash memory has its advantages in front of other drives (hard drives and optical drives), as well as its shortcomings, which you can get acquainted with from the table below.
Drive type | Advantages | Flaws |
HDD | Large amount of stored information. High speed. Low cost of data storage (per 1 MB) | Large dimensions. Sensitivity to vibration. Noise. Heat dissipation |
optical disc | Ease of transportation. Cheap storage of information. Possibility of replication | Small volume. You need a reader. Restrictions on operations (reading, writing). Low speed. Sensitivity to vibration. Noise |
Flash memory | High speed data access. Economical power consumption. Vibration resistant. Ease of connecting to a computer. Compact dimensions | Limited number of write cycles |
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 science.
How did it all start?
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. At the same time, such an item stores data for a long time without using additional equipment.
If an energy source is needed to store information on electronic media, then a simple data carrier can turn out to be stone, wood, paper, metal and other materials.
An information carrier can be any object that shows the data printed on it. It is believed that information carriers are needed for recording, storing, reading, and transmitting materials.
Peculiarities
It is not difficult to guess that an electronic information carrier is a kind of information carrier. It also has its own classification, which, although not officially established, is used by many specialists.
For example, electronic media may be recorded once or repeatedly. Here are the devices:
- optical;
- semiconductor;
- magnetic.
Each of these mechanisms has several types of equipment.
An electronic information carrier is, first of all, a number of advantages over paper versions. First, thanks to technology, the volume of data to be archived can be virtually unlimited. Secondly, the collection and presentation of up-to-date information is ergonomic and fast. Thirdly, digital data is presented in a convenient form.
But electronic media has its drawbacks. For example, this may include the unreliability of the equipment, in some cases the dimensions of the device, dependence on electricity, as well as the requirement for the constant availability of a device that could read files from such a digital drive.
Variety: optical discs
An electronic storage medium is a device that can be optical, semiconductor, magnetic. This is the only classification of such equipment.
In turn, optical devices are also divided into types. This includes LaserDisc, CD, MiniDisc, Blu-ray, HD-DVD and so on. The optical disc is named so due to the technology of reading information. Reading from a disk occurs with the help of optical radiation.
The idea of this electronic media was born a long time ago. The scientists who developed the technology were awarded Nobel Prize. The way to reproduce information from an optical disc appeared in 1958.
Now optical electronic media has 4 generations. The first generation were: 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, the Holographic Versatile Disc and SuperRens Disc are actively developed.
Semiconductor carriers
The next type of electronic storage medium is semiconductor. This includes flash drives and SSD drives.
Flash memory is the most popular electronic media that has 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 period of use and dependence on electrostatic discharge. The flash drive was first talked about in 1984.
An SSD drive is a solid-state electronic storage medium, also known as 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, 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 is not used now, 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 drive of most modern computer systems.
Its main difference from the previous type, a floppy disk, is that the 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 used only in computer technology.
The distribution of electronic media is associated with the convenience of its use, high speed of writing and reading. Therefore, this equipment displaces paper media.
The documents
What is an electronic passport? At first, this question can drive a person into a dead end. But if you think about it carefully, then such a thing as a “biometric passport” comes to mind.
This is a state document that certifies the identity and citizenship of the traveler at the time of his moving abroad and staying in another country. In fact, we have the same passport, but with some nuances.
The difference between a biometric document and a traditional passport is that the former carries a specially built-in microchip that stores the holder's photo and personal data.
Thanks to a small chip, you can get the last name, first name and patronymic of the owner of the document, his date of birth, passport number, time of issue and end of the validity period. According to the sample, the microchip should contain human biometric data. This includes the drawing of the iris of the eye or a fingerprint.
Document Introduction: Advantages and Disadvantages
Despite the fact that a 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 the passage of the border checkpoint now does not take much time. If such places have special equipment, which can read the microchip, then the border crossing becomes safe and fast.
But not all citizens like the biometric passport. Many believe that the introduction of such a document is a manifestation of total control, behind which stands the US government.
Criminal case
The development of electronic media has affected many areas. This also applies to criminal cases. In 2012, the term electronic media was introduced into the Code of Criminal Procedure 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 carrier should be directly related to the investigation. In addition, they must be transmitted by a reliable source that could be verified. The data must be in a specific form, such as video, photos, 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 media. In this case, a log is started in which all devices are registered. Each is assigned an identification number.
The importance of electronic media in a criminal investigation is a controversial issue to this day. Legislatively, such devices are not classified as any source of evidence. This may lead to disagreements.
conclusions
Electronic storage media for a modern person is a real find. With the development of technology, the volume of archives that store data is becoming larger. Every year there are new opportunities for transmitting and reading information.