Used for long-term storage of files. Classification of long-term information storage devices

Classification of long-term information storage devices

The most common are magnetic disk drives, which are divided into drives hard magnetic disk drives (HDDs) and floppy disk drives (FMDs), and optical disk drives such as CD-ROM drives, CD-R, CD-RW and DVD-ROM.

Detailed characteristics of long-term information storage devices

· Hard magnetic disk drives (HDD)

HDD is the main device for long-term storage of large amounts of data and programs. Other names: HDD, hard drive, HDD (Hard Disk Drive). Externally, the hard drive is a flat, hermetically sealed box, inside of which there are several round rigid aluminum or glass plates on a common axis. The surface of any disk is covered with a thin ferromagnetic layer (a substance that reacts to an external magnetic field), and the recorded data is actually stored on it. In this case, recording is carried out on both surfaces of each plate (except for the outer ones) using a block of special magnetic heads. Each head is located above the working surface of the disk at a distance of 0.5-0.13 microns. The disk pack rotates continuously and at high speed (4500-10000 rpm), so mechanical contact of heads and disks is unacceptable.

There is a huge amount different models hard drives many companies such as Seagate, Maxtor, Quantum, etc. To ensure compatibility of hard drives, standards have been developed for their characteristics, which determine the range of connecting conductors, their placement in adapter connectors, and the electrical parameters of signals. The most common interface standards are IDE (Integrated Drive Electronics) or ATA and the more productive EIDE (Enhanced IDE) and SCSI (Small Computer System Interface). Characteristics of the interfaces through which hard drives are connected to motherboard, largely determine the performance of modern hard drives.

Among other parameters that affect HDD performance, the following should be noted:

• § disk circulation speed - nowadays EIDE drives are produced with a circulation frequency of 4500-7200 rpm, and SCSI drives - 7500-10000 rpm;
• § cache memory capacity - all modern disk drives have a cache buffer installed, which speeds up data exchange; the greater its capacity, the higher the likelihood that the cache memory will contain the necessary information that does not need to be read from the disk (this process is thousands of times slower); cache buffer capacity in different devices can vary from 64 KB to 2 MB;
• § average access time - the time (in milliseconds) during which the head block moves from one cylinder to another. Depends on the design of the head drive and is approximately 10-13 milliseconds;
• § delay time is the time from the moment the head block is positioned on the desired cylinder to the positioning of a specific head on a specific sector, in other words, this is the time to search for the desired sector;
• § exchange rate - determines the amount of data that can be transferred from the drive to the microprocessor and to reverse direction for certain periods of time; maximum value this parameter is equal to the disk interface bandwidth and depends on which mode is used: PIO or DMA; in PIO mode, data exchange between the disk and the controller occurs with the direct participation of central processor, the larger the PIO mode number, the higher the communication speed; working in DMA (Direct Memory Access) mode allows you to transfer data directly to RAM without the participation of the processor; Data transfer speeds in modern hard drives range from 30-60 MB/s.
• · Floppy magnetic disk drives (FMD)

The float drive or disk drive is built into system unit. Flexible media for floppy disk drives are produced in the form of floppy disks (another name for floppy disk). Actually, the carrier is a flat disk with a special, fairly dense film, coated with a ferromagnetic layer and placed in a protective envelope with a movable latch at the top. Floppy disks are used mainly for quickly transferring small amounts of information from one computer to another. Data recorded on a floppy disk can be protected from being erased or overwritten. To do this, you need to move the small protective slide at the bottom of the floppy disk so that an open window is formed. To enable recording, this slider should be moved back and the window closed.

The main parameters of a floppy disk are the technological size (in inches), recording density and total capacity. By size, there are 3.5-inch floppy disks and 5.25-inch floppy disks (no longer used). The recording density can be simple SD (Single Density), double DD (Double Density) and high HD (High Density). The standard capacity of a 3.5-inch floppy disk is 1.44 MB; floppy disks with a capacity of 720 KB can be used. The current standard is 3.5-inch, high-density HD floppy disks with a capacity of 1.44 MB.

CD-ROM drive

Since 1995, the basic configuration of a personal computer began to include a CD-ROM drive instead of 5.25-inch drives. The abbreviation CD-ROM (Compact Disk Read Only Memory) is translated as a read-only storage device based on compact discs. The operating principle of this device is to read digital data using a laser beam that is reflected from the surface of the disk. A regular CD is used as a storage medium. Digital recording recording on a CD is different from recording on magnetic disks high density, so a standard CD has a capacity of about 650-700 MB. Such large volumes are typical for multimedia information (graphics, music, video), so CD-ROM drives are classified as multimedia hardware. In addition to multimedia publications ( e-books, encyclopedias, music albums, videos, computer games) a variety of large-volume system and application software (operating systems, office packages, programming systems, etc.) are distributed on CDs.

CDs are made of transparent plastic with a diameter of 120 mm and a thickness of 1.2 mm. A layer of aluminum or gold is sprayed onto the plastic surface. In mass production conditions, information is recorded on a disk by extruding tracks on the surface in the form of a series of indentations. This approach provides binary recording of information. Recess (pit - pit), surface (land - land). Logical zero can be represented by either a pit or a land. A logical one is encoded by the transition between pit and land. From the center to the edge of the CD there is a single track in the form of a spiral 4 microns wide with a pitch of 1.4 microns. The surface of the disk is divided into three areas. Lead-In is located in the center of the disk and is read first. It records the contents of the disk, a table of addresses of all records, the disk label and other service information. The middle area contains basic information and takes up most of the disk. The Lead-Out area contains the end-of-disk mark.

For stamping, there is a special prototype matrix (master disk) of the future disk, which extrudes tracks on the surface. After stamping, apply to the surface of the disk protective film from transparent varnish.

Main characteristics of CD-ROM:

• § data transfer rate - measured in multiples of the speed of an audio CD player (150 KB/sec) and characterizes the maximum speed at which the drive transfers data to the computer’s RAM, for example, a 2-speed CD-ROM (2x CD-ROM) will read data at a speed of 300 KB/sec, 50-speed (50x) - 7500 KB/sec;
• § access time - the time required to search for information on the disk, measured in milliseconds.

The main disadvantage of standard CD-ROMs is the inability to write data, but there are one-time devices CD-R recordings and reusable CD-RW recording.

CD-R drive (CD-RECORDABLE)

Externally similar to CD-ROM drives and compatible with them in disc size and recording formats. Allows one-time recording and an unlimited number of readings. Data recording is carried out using a special software. The recording speed of modern CD-R drives is 4x-8x.

CD-RW drive (CD-REWRITABLE)

They are used for reusable recording of data, and you can either simply add new information to free space or completely overwrite the disk with new information (previous data is destroyed). As with CD-R drives, in order to burn data, you must install special programs, and the recording format is compatible with regular CD-ROM. The recording speed of modern CD-RW drives is 2x-4x.

DVD drive (DIGITAL VIDEO DISK)

A device for reading digital video recordings. Externally, a DVD disc is similar to a regular CD-ROM (diameter - 120 mm, thickness 1.2 mm), but differs from it in that up to 4.7 GB can be recorded on one side of the DVD disc, and up to 9.4 GB. If a two-layer recording scheme is used, up to 8.5 GB of information can be placed on one side, respectively, on two sides - about 17 GB. DVDs can be rewritten.

· Outlook DVD

The presence of different standards and specifications does not mean that DVD technology stands still. The efforts of various companies today are aimed at introducing “blue laser” technology - with a shorter wavelength. This will increase the recording density on disks with the resulting improvement in other characteristics.

Calimetrics Inc has proposed ML (multilevel) technology, which can triple the capacity of a standard DVD/CD. In this case, there is no need to make any modifications to the mechanism and optics of existing drives. For implementation new technology It is enough to use a chipset developed by this company. The essence of the technology is the ability to use pit depth (up to 8 levels) as an information characteristic when working with disks. Note that a similar technology, but for CD discs, is being developed by TDK in collaboration with other companies.

• Read-only DVD formats
• Ш DVD-ROM (Digital Versatile Disc Read Only Memory)

DVD-ROM discs are intended for use in computer technology. Information is written to the disk only once - during its production.

The progress of DVD devices largely follows the path traversed by CDs, and is aimed mainly at improving speed characteristics and introducing a recording function. First-generation DVD-ROM devices used CLV mode and read from the disc at a speed of 1.38 MB/s (in traditional DVD notation this is 1x). Second-generation devices could read DVDs at twice the speed - 2x (2.8 MB/s). Modern DVD-ROMs - third-generation devices - use rotation control mode (CAV) with a maximum reading speed of 4x-6x (5.5 - 8.3 MB/s) or more. Modern DVD-ROM drives (disk drives) support reading almost all formats, including CDs.

The DVD-Video format is designed for storing and playing video. Like DVD-ROM, this specification defines the ability to read-only information - playback of recordings using video players (video recorders). The specification is based on the DVD-ROM format, but provides special way data placement, preventing the possibility of bit-by-bit copying of disks. Video materials in encoded form are placed on the disk during its production process. Playing DVD-video is only possible on household video players (video recorders) or DVD drives connected to a computer. When using computer equipment, information decoding is carried out either in hardware or software. The modern specification ensures recording of high-quality video on disc (up to 2 hours in MPEG-2 compression format). And also multi-channel audio in 8 languages, choice of screen format, captions in 32 languages, interactive control via on-screen menu, up to 9 angular viewing directions, protection against illegal copying, delimitation of viewing video products by region, control of children’s access to video materials.

A new generation of music format after CD. The format specification defines high quality multi-channel audio, support for a wide range of sound quality (quantization 16, 20, 24 bits at frequencies from 44.1 to 192 kHz), playback of DVD CD players, support for additional information (including video, text, menus, screensavers, convenient navigation system), connection with websites providing information support, expanding opportunities when new technologies emerge.

There are two versions of the DVD-Audio format: simply DVD-Audio - for audio content only, and DVD-AudioV - for audio with additional information.

Special measures have been developed to protect disks from pirated copying.

• · DVD formats for multiple recording
• Ш Multiple write

All known rewritable specifications DVD discs use multiple recording technology based on the physical principle of changing the phase state (crystalline/amorphous) of the information layer under the influence of a laser with a wavelength of 650 (635) nm (phase-change recording). Reading information is carried out by determining the optical characteristics of the information layer in its various phase states upon reflection of laser beams (the same as during recording).

Ш DVD-RAM (Digital Versatile Disc Random Access Memory)

Rewritable format developed by Panasonic, Hitachi, Toshiba.

The format was approved by the DVD forum in July 1997. Equipment and discs of this format were tested for 3 months in more than 20 computer manufacturing companies around the world. Over 160 forum participants voted to accept the specification. Today it is the most common DVD format in the computer industry.

DVD-RAM drives read DVD-R discs OM. In turn, DVD-RAM discs can only be read by so-called third-generation DVD-ROM drives produced since mid-1999.

First generation DVD-R discs AM held 2.6 GB per side. Modern second-generation drives carry 4.7 GB per side or 9.4 GB for a two-sided version.

Two types of single-sided DVD-RAM discs are available - in a cartridge and without a cartridge. Discs in a cartridge are mainly intended for household video equipment, where it is necessary to exclude the influence of external factors during intensive manual use. Cartridges, in turn, can be of two types - openable and solid.

The most important advantages of DVD-RAM format discs are the ability to be rewritten up to 100,000 times and the presence of a recording error correction mechanism.

The largest number of rewrite cycles among all DVDs, an error correction mechanism and random access to the disk, both during writing and reading, predetermined the maximum efficiency of this format in secondary storage devices. The vast majority of mass storage devices - robotic DVD libraries - use precisely this technology.

DVD-RAM discs can be used to record and play streaming video on equipment that supports the DVD-VR specification (see below).

Ш DVD+RW (Digital Versatile Disc ReWritable)

The DVD+RW format is promoted only by its developers - Hewlett-Packard, Mitsubishi Chemical, Philips, Ricoh, Sony and Yamaha (not supported by the DVD forum).

On DVDs+RW can record both streaming video or audio and computer data. DVD+RW discs can be rewritten approximately 1000 times.

Based on DVD+RW, a streaming video recording format has been created - DVD+RW Video Format. Devices and discs operating in this format are positioned on the market as fully compatible with equipment operating in DVD-Video formats. This means that DVD+RW discs containing video content can be played on older consumer DVD equipment.

Philips announced the launch of its DVD video recorder in September 2001. DVD+RW discs recorded on this device can also be read by conventional DVD-Video players. This solution was proposed as a response to the DVD-VR specification adopted by the DVD forum (see below).

Ш DVD-RW (Digital Versatile Disc ReRecordable)

There are other names for this format: DVD-R/W and less commonly DVD-ER.

DVD-RW is a rewritable format developed by Pioneer. DVD-RW format discs hold 4.7 GB per side, are available in single-sided and double-sided versions and can be used to store video, audio and other data.

DVD-RW discs can be rewritten up to 1000 times. Unlike DVD+RW and DVD-RAM formats, DVD-RW discs can be read on first-generation DVD-ROM drives.

TDK claims that its DVD-RW discs have a lifespan of approximately 100 years.

• · Write-once DVD formats
• Ш DVD-R (Digital Versatile Disc Recordable)

DVD-R is a write-once format developed by Pioneer. Devices based on this format were the first to record DVDs. The recording technology is similar to that used in CD-R and is based on an irreversible change under the influence of a laser in the spectral characteristics of an information layer coated with a special organic composition.

DVD-R discs can be recorded as computer data, multimedia programs, and video/audio information. Depending on the type of information recorded, discs can be read on other types of devices compatible with the recorded format, including DVD-Video video players and most DVD-ROM drives. Single-sided DVD-R discs hold 4.7 or 3.95 GB per side. Double-sided discs are only available total capacity 9.4 GB (4.7 GB per side). Currently, the format does not support dual-layer recording technology.

The durability of DVD-R discs is estimated at over 100 years. To protect against illegal copying, two specifications have been developed: DVD-R(A) and DVD-R(G). These two versions of the same specification use different laser wavelengths when recording information. Thus, discs can only be written on equipment that meets their specifications. Disc playback can be performed equally successfully on any equipment that supports the DVD-R format.

DVD-R(A) (DVD-R for Authoring) is used in professional applications. In particular, support for a special format (Cutting Master Format) allows you to use these discs to record the original replica of information (premastering) instead of the usual use of DLT tapes for these purposes.

DVD-R(G) (DVD-R for General) is intended for wider use. Disks of this format are protected from the possibility of bit-by-bit copying of information onto them from other disks. The format is supported in mass storage devices (for example, in robotic DVD libraries offered by Pioneer itself).

The DVD-VR specification is based on DVD-RAM and is supported by the DVD Forum. The DVD-VR format allows you to record up to 2 hours of high-quality MPEG-2 video in real time on a single-sided 4.7 GB DVD-RAM disc and provides capabilities such as editing of already recorded video footage, recording various types static images. Electronics based on this format are produced, for example, by Panasonic, Toshiba, Samsung, Hitachi.

With the advent of computers, the issue of storing information that was initially provided in digital form became very acute. And now this problem is very relevant, because you want to save the same photos or videos for a long memory. That is why you will initially have to find an answer to the question of which devices and media are used for long-term storage of information. You should also fully appreciate all their advantages and disadvantages.

The concept of information and methods of storing it

Nowadays, you can find several main types of information data on computers. The most common forms are text, graphic, audio, video, mathematical and other formats.

In the very simple version Computer hard drives are used to store information, on which the user initially saves the file. But this is only one side of the coin, because in order to view (extract) this information, you need at least an operating system and corresponding programs, which, by and large, also represent information data.

It is interesting that in computer science classes in schools, when choosing the correct answer to such questions, one often comes across the statement that, supposedly, RAM is used for long-term storage of information. And schoolchildren who are not familiar with the specifics and principles of its work consider this the correct answer.

Unfortunately, they are wrong, since RAM only stores information about the running this moment processes, and when they are completed or the system is rebooted, the RAM is completely cleared. This is similar to the principle of the once popular children's drawing toys, when you could first draw something on the screen, and then shake the toy, and the drawing would disappear, or when the teacher erases text written in chalk from the blackboard.

How information was stored before

The very first method of preserving information in the form of rock paintings (graphics, by the way) has been known since time immemorial.

Much later, with the advent of speech, the preservation of information began to be a process, so to speak, of transmission from mouth to mouth (myths, legends, epics). Writing led to the appearance of books. Paintings or drawings were not forgotten either. With the advent of photography, sound and video recording technologies, corresponding media appeared on the information field. But all this turned out to be short-lived.

Device for long-term storage of information: basic requirements

As for computer systems, you should clearly understand exactly what requirements modern media must meet in order for information to be stored on them for as long as possible.

The most important requirement is durability and resistance to wear and physical or other damage. And in relation to any type of media, we can talk about time intervals very relatively, because, as we know, “nothing lasts forever under the moon.”

What media are used for long-term storage of information?

Now let's move directly to devices on which data of any type can be stored, if not forever, then at least for a long time. So, what types of media are used for long-term storage of information?

Among the most frequently used in relation to computer technology are the following:

• internal and removable hard drives and ZIP drives of computers;
• optical CDs, DVDs and Blu-ray media;
• flash memory of any type;
• floppy disks (nowadays they are used extremely rarely).

Advantages and disadvantages of media

As can be seen from the list above, only hard drives built into computers are classified as internal data storage devices. All other media are external.

But they are all, to one degree or another, susceptible to aging or external influences. In this sense, floppy disks or the same CDs or media of other formats are the most unsafe, although optical media in this regard seem to be more durable. But how long can they last? 5-10 years? But if the information stored on them is viewed very often, the service life is reduced.

Flash drives and hard drives have longer service life, but they are not immune to wear, damage and aging.

Hard drives begin to “crumble” (this is a natural process), flash drives can be exposed to the same sunlight, moisture or even delete data if extracted incorrectly or software failures. In addition, there are many additional factors that can lead to device inoperability.

However, speaking about the fact that the devices listed above are used for long-term storage of information, it is worth considering that such a classification is given exclusively for the current state of affairs in computer world. Who knows, maybe even in the foreseeable future completely new media will be invented that use other technologies, because, as stated, the creation of quantum computers is just around the corner.

We will share our experience in working with different drives and tell you which ones are reliable and which ones are better not to store anything valuable. You will learn how to keep your data safe and secure for at least a century.

General rules for storing valuable information

There are several rules that apply to any information that is important to keep safe and sound. If you don’t want to lose photos dear to your heart, important documents or valuable works, then:

• Make as many copies as possible. This way, you will insure yourself with several spare copies, and if one copy is lost, you will still have a couple of other copies.
• Store data only in the most common and accepted formats. You shouldn’t resort to exotic things and use little-known file types, because one day you simply won’t be able to find a program to open it (for example, it’s better to store texts in ODF or TXT, rather than DOCX and DOC).
• After making several copies, place them on different media; do not store everything on the same hard drive.
• Do not use data compression or encryption. If such a file becomes even slightly damaged, you will never be able to access it and open the contents. For long-term storage of media files, use uncompressed formats. For audio this is WAV, for images RAW, TIFF and BMP are suitable, video files are DV. True, you will need a medium with a large enough capacity to accommodate such files.
• Constantly check the integrity of your information and create additional copies in new ways and on newer devices.

Such simple rules will help you preserve important documents, expensive photos and video recordings for many years. Now let’s look at where the information will be safe and sound for the longest time.

About popular media and their reliability

The most common and popular storage methods digital information applies – use of hard drives, Flash media ( SSD drives, flash drives and memory cards), recording optical discs (CD, DVD and Blu-Ray discs). Additionally, there are many cloud storage for any data (Dropbox, Yandex Disk, Google Drive and many others).

Which of the above do you think is best place storage important information? Let's explore each of these methods.

As you understand, among the most available ways, it is best to store your data on optical disks. But not all of them are able to cope with the passage of merciless time, and then you will find out which ones are better suited for our purposes. Besides, good decision will be the use of several of the mentioned methods at the same time.

Let's use optical discs correctly!

Some of you may have heard about how long information can be stored on optical discs such as CDs or DVDs. Some probably even wrote certain data to them, but after a while (several years) the disks could not be read.

In fact, there is nothing surprising here; the storage life of information on such media also depends on many factors. First of all, the quality of the disk itself and its type play an important role. In addition, you must adhere to certain storage conditions and the recording process.

• Do not use rewritable types of discs (CD-RW, DVD-RW) for long-term storage; they are not designed for this purpose.
• Testing has shown that statistically the longest storage period for information is with CD-R discs and it exceeds 15 years. Only half of all DVD-Rs tested showed similar results. As for Blu-ray, it was not possible to find exact statistics.
• You shouldn’t chase cheapness and buy blanks that sell for pennies. They are of very low quality and are not suitable for important information.
• Burn discs at minimum speed and do everything in one recording session.
• Discs should be stored in a place protected from direct sunlight, at a stable, room temperature and moderate humidity. Do not subject them to any mechanical stress.
• In some cases, the recording itself is also affected by the quality of the drive that “cuts” the blanks.

Which drive should you choose for storing data?

As you already understand, there are different discs. All the main differences are related to the reflective surface, the type of polycarbonate base and overall quality. It is even possible to take products from the same company, but manufactured in different countries, then even here the quality can vary by an order of magnitude.

Cyanine, phthalocyanine or metallized layers are used as the surface on which recording is made. The reflective surface is created by gold, silver or silver alloy coating. The highest quality and most durable discs are made from phthalocyanine with gold plating (since gold is not subject to oxidation). But there are wheels with other combinations of these materials that also boast good durability.

To my great disappointment, I tried to find special disks for storing data; it’s almost impossible to find them here. If desired, such optical media can be ordered via the Internet (not always cheap). Among the leaders that can save your information for at least a century are DVD-R and CD-R Mitsui (this manufacturer generally guarantees up to 300 years of storage), MAM-A Gold Archival, JVC Taiyu Yuden and Varbatium UltraLife Gold Archival.

Among the most ideal options for storing digital information you can add Delkin Archival Gold, which are not found anywhere in our country. But as already mentioned, all of the above can be ordered without much difficulty in online stores.

Of the available disks that can be found with us, the highest quality and capable of ensuring the safety of information for at least a decade will be:

• Verbatium, Indian, Singapore, UAE or Taiwan made.
• Sony, which are created in the same Taiwan.

But the fact that all these disks can store information for a long time does not guarantee that it will be preserved for a long time. Therefore, do not forget to adhere to the rules that we outlined at the very beginning.

Take a look at the following graph; it shows the dependence of the occurrence of data reading errors on the time the optical disk is in an aggressive environment. It is clear that the graph was created specifically for the marketing promotion of the product, but still note that it contains a very interesting Millenniata, on the disks of which no errors appear at all. Now we will learn more about her.

Millenniata M-Disk

Among the products of this company are the M-Disk DVD-R and M-Disk Blu-Ray series discs capable of storing important data for up to 1000 years. Such amazing reliability is achieved by using inorganic glassy carbon as the basis for the discs, which, unlike other discs that use organic materials, is not subject to oxidation or decomposition under the influence of light and heat. Such discs will easily withstand the ingress of acids, alkalis and solvents, and also boast higher resistance to mechanical stress.

During recording, small windows are literally burned on the surface (on ordinary discs pigmentation of the film occurs). The disc base is similarly designed for more severe tests and is able to maintain its structure even when exposed to high temperatures.

And information. It’s clear that you want to keep things like wedding photos or videos for a long time. However, how to do this?

Concept

Computer science determines that for long-term storage of information, that is, all possible storage devices and media that you can imagine. As you understand, there are different ways to ensure the safety and security of data. Let's determine what forms of information storage exist.

• Graphic/pictorial. The most ancient method, adapted for It appeared in prehistoric times in the form of cave paintings, went through the stage of painting and turned into the art of photography. In addition, information is presented graphically in the form of drawings and diagrams.
• Text. The most common method of storing data today. A wide variety of books and records, libraries. If we talk about reliability, then this storage method is not only not protected from theft, but is also short-lived. The best preserved cookbooks are those that were originally printed on materials adapted to an aggressive environment.
• The next step after the invention of writing is mathematics , a numerical form of storing information. A fairly highly specialized area, used to determine quantitative characteristics any object in the surrounding space.
• Sound recording. The ability to store sounds only appeared in 1877 with the invention of sound recording devices.
• Video information. The next step in storage graphic information, which appeared with the creation of cinema.

Information processes

Information processes mean search, storage, transmission, use, and the main and primary concern is the preservation of data. What difference does it make whether we can receive or transmit information if we cannot store it?

The main one is the process of storing information. It is a way of transmitting data in space and time. For long-term storage of information, a device or device is used, depending on the type of data stored. To ensure orderliness of this process, use Information Systems. Any such system is equipped with procedures for searching, placing and input/output of data. Home distinctive feature information system is the presence of all these key procedures. For example, let's compare two libraries. The private library in your closet at home is not an information system, since only you can navigate it. On the other hand, a public city library, in which everything is organized according to a card index and there are standardized procedures for issuing and receiving books, is undoubtedly a system.

Computer age

With the development of not even the computer, but the Internet, information systems are being modernized. The storage process has been simplified due to the possibility of converting it into digital form. And despite the belief of some people that e-books or paintings do not carry a soul, this method of storing data is much more effective than others for long-term storage of information, and it includes all possible information, if only you can convert it into digital view.

Modernity

For long-term storage of information it is used Personal Computer and him external devices. They are divided into several types depending on the recording method.

• optical disks;
• hard disks;
• flash memory.

They have a wide variety of volumes and are best suited for transmitting and storing information. Hard disks designed for storing large amounts of data, but their reliability leaves much to be desired. And, of course, flash drives. They are a middle link between hard and optical disks, ensure storage of information in sufficient volumes and for a sufficiently long period of time, just do not get them wet. In any case, the storage method is up to you.

A) working memory. B) processor. B) external memory
2. When disconnecting the computer from the information network:
A) disappears from random access memory
B) disappears from permanent storage
B) erased on a magnetic disk
3. Each RAM cell can store binary code long...
A) 2 characters b) 8 characters c) 4 characters
4. A volatile type of memory is:
A) flash memory b) CD c) hard drive
5. K internal memory computer refers to:
A) flash memory b) laser disc c) RAM

electronic number processing device;
a device for storing information of any kind;
multifunctional electronic device for working with information;
processing device analog signals.
2. Computer performance (speed of operations) depends on:
monitor screen size;
processor clock speed;
supply voltage;
speed of pressing the keys;
volume of information processed.
3. Clock frequency processor is:
the number of binary operations performed by the processor per unit of time;
the number of cycles performed by the processor per unit of time;
the number of possible processor accesses to RAM per unit of time;
speed of information exchange between the processor and I/O device;
speed of information exchange between the processor and ROM.
4. A mouse is a device:
entering information;
modulation and demodulation;
reading information;
to connect the printer to your computer.
5. The permanent storage device is used for:
storing the user program during operation;
records of particularly valuable application programs;
storing constantly used programs;
program storage bootstrap computer and testing its components;
permanent storage of particularly valuable documents.
6. For long-term storage of information the following is used:
RAM;
CPU;
magnetic disk;
drive.
7. Storing information on external media differs from storing information in RAM:
the fact that information can be stored on external media after the computer is turned off;
volume of information storage;
the ability to protect information;
ways to access stored information.
8. During execution of application programs the following is stored:
in video memory;
in the processor;
in RAM;
in ROM.
9. When the computer is turned off, the information is erased:
from RAM;
from ROM;
on a magnetic disk;
on CD.
10. Drive floppy disks- this is a device for:
processing commands of the executable program;
reading/writing data from external media;
storing commands of the executable program;
long-term storage of information.
11. To connect a computer to the telephone network, use:
modem;
plotter;
scanner;
Printer;
monitor.
12. Software control computer operation involves:
need to use operating system for synchronous operation of hardware;
execution by a computer of a series of commands without user intervention;
binary coding of data in a computer;
using special formulas to implement commands in a computer.
13. The file is:
an elementary information unit containing a sequence of bytes and having a unique name;
an object characterized by name, value and type;
a set of indexed variables;
a set of facts and rules.
14. The file extension, as a rule, characterizes:
file creation time;
file size;
the space occupied by the file on the disk;
the type of information contained in the file;
file creation location.
15. Full path to the file: c:\books\raskaz.txt. What is the file name?
books\raskaz;.
raskaz.txt;
books\raskaz.txt;
txt.
16. The operating system is -
a set of basic computer devices;
language programming system low level;
software environment that defines the user interface;
a set of programs used for operations with documents;
programs for destruction computer viruses.
17. Programs for pairing computer devices are called:
loaders;
drivers;
translators;
interpreters;
compilers.
18. A system floppy disk is required for:
for emergency loading of the operating system;
file systematization;
storing important files;
treating your computer for viruses.
19. Which device has highest speed exchange of information:
CD-ROM drive;
HDD;
floppy disk drive;
RAM;
processor registers?

volatile.

e) Faster access.

g) Slower access.

2. Which one Memory V bytes will occupy the next binary

3. Volume text 1024 bits located in random access memory, starting from the byte with the number 10 . What will be the address last byte

4. List at least five devices you know external memory.

5. What difference disks CD- ROM, CD- RW And CD- R?

It is volatile.

b) Its volume is measured in tens and hundreds of gigabytes.

c) Used for long-term storage of information.

d) Its volume is measured in hundreds of megabytes or several gigabytes.

e) Faster access.

f) Used for temporary storage of information.

g) Slower access.

2. How much memory in bytes will the following binary code occupy: ? Explain your answer.

3. Text with a volume of 1024 bits is located in RAM, starting with byte number 10. What will be the address of the last byte that is occupied by this text?

4. List at least five devices you know of external memory.

5. What is the difference between CD-ROM, CD-RW and CD-R discs?

operational, and which ones - to external memory?

a) It is volatile.

b) Its volume is measured in tens and hundreds of gigabytes.

c) Used for long-term storage of information.

d) Its volume is measured in hundreds of megabytes or several gigabytes.

e) Faster access.

f) Used for temporary storage of information.

g) Slower access.

2. Which one Memory V bytes will occupy the next binary code: ? Explain your answer.

3. Volume text 1024 bits located in random access memory, starting from the byte with the number 10 . What will be the address last byte, which is occupied by this text?

4. List at least five devices you know external memory.