The name of the flash card. What is a flash drive? Description and photo

information

An information carrier using flash memory (eng. Flash - “fast, instantaneous”) is a microcircuit with electronic non-volatile memory capable of storing recorded information for an unlimited time and maintaining its state until an electrical signal of a different polarity is applied to the outputs. These are high-quality universal rewritable storage media, focused on consumer electronics products and next-generation computer equipment.

Flash memory is available in the following types: CompactFlash, SmartMedia, Memory Stick, Floppy Disks, MultiMedia Cards, etc.

MultiMedia cards, for example, weigh less than two grams, are the size of a postage stamp, and have memory capacities ranging from 8 to 64 MB. Such cards can replace not only floppy disks, but magneto-optical, small hard disks and rewritable CDs. Modern flash cards have a capacity that is a multiple of two to the power: 26 = 64, 27 = 128, 256 = 28 MB, and so on. It is assumed that the maximum capacity of such cards will reach units of GB. Such plug-in cards are used in digital voice recorders, portable players, camcorders, car radios, personal digital assistants (PDAs), cell phones and multimedia projectors.

Information carriers distinguish by physical structure(magnetic, semiconductor, dielectric, etc.), material type(paper, plastic, metal, combined), data presentation form(printed, handwritten, magnetic, perforated), reading principle(mechanical, optical, magnetic, electrical), design(tape, disk, card).Information carriers can also be classified according to the type of messages stored on them, and the materials of information carriers are characterized by the purpose of their use.

By intended use data carrier materials can be classified as materials used for recording, presenting and storing textual, digital, graphic data, static and dynamic images, sound (magnetic and non-magnetic) or a combination thereof, for example, multimedia data. Both classifications are closely interconnected; moreover, it is impossible to unambiguously classify carrier materials. The kinds of different messages are shown in Table 5-1.

Table 5-1

Types of different messages

Message type	Information carrier
Text	Document
Sound	Phonogram
Image (static)	Photograph, graphics, drawing, etc., transparencies (slide), hologram, static image or text information scanned with a PC
Image (dynamic)	Animation, video film, motion picture, TV
Combination of different types of information	Multimedia

as static carriers images used: paintings, etchings, drawings, etc. on canvas, cardboard, paper, film, etc.; video cassettes with magnetic tapes for VCRs and video players; magnetic vinyl diskettes; removable and non-removable hard and magneto-optical disks; compact plastic or glass laser discs ( CD, DVD ) used in computers; slides and transparencies, photographic materials, holographic plates, plates with memory for digital cameras such as flash memory, etc.

For the operation of audio-video equipment as sound carriers and/or dynamic images used: films and plastic gramophone records, magnetic audio and audiovisual tapes, films, vinyl diskettes, hard magnetic, magneto-optical disk drives, compact disks, memory plates for digital cameras and cameras, holographic plates, etc.).

multimedia data carriers magnetic audio and audiovisual tapes, floppy disks, drives on hard magnetic, magneto-optical disks, compact disks, memory plates are considered.

Various requirements for their operation and storage (climatic, sanitary and hygienic, fire-prevention, technical, technological, etc.) are imposed on information carriers.

Consider the basic materials of information carriers and their forms.

carriers images:

1. Paper . Historians claim that paper was invented in China about 2,000 years ago. However, much earlier (approximately since VIII century AD), the ancient Egyptians made scrolls from papyri, from where the word denoting the paper carrier "papyr" came from. Then the basis of paper carriers were rice straw, bamboo, rags, wood and other materials.

Synthetic (polyethylene) paper has been industrially used abroad since April 1967. The fibers of the material, called " Tyvek» ( Tyvek ) have a thickness (diameter) of 0.5–1 µm. It is a smooth and opaque material that incorporates the best properties of film, paper and fabric. It has a low specific gravity, high strength, resistance to punctures, tear and abrasion, vapor permeability, water repellency, rot resistance and biological inertness. Experts say that this material can replace traditional paper, especially in the manufacture of envelopes and any printing.

The material is resistant to most chemicals and is suitable for varnishing, laminating, heat sealing and bonding. It retains strength and flexibility up to a temperature of 73°C. It is believed that it is most suitable for outdoor advertising, covers of textbooks, geographical maps, guidebooks, etc., as it does not fray on the folds and does not deteriorate from water. However, to print on such material, you have to use special inks.

Similar material " Polylith» ( Polylith ) was imported to Russia in 1998. It is made from polypropylene resin mineral hardened with a mixture of neutral calcium and titanium dioxide to give a white and dull finish. It is the cheapest of synthetic materials, is resistant to water, heat, oil and chemicals. Another similar material is Robuskin» ( Robuskin ), an important distinguishing feature of which is the ability to print on it with conventional inks with virtually no readjustment of the printing equipment used for plain paper. There are, of course, other synthetic materials, including those with a self-adhesive backing.

The paper base is used in books, manuscripts, maps, diagrams and other similar documents. From the beginning of the appearance of manuscripts, books and until the middle XIX centuries, they were created mainly on paper from cotton and linen fibers. This is durable paper. From the end of the 19th and into the 20th centuries, paper was used mainly sulfite pulp and wood pulp. Modern books are mainly used as a carrier cellulosic materials.

2.Canvas, cardboard, hardboard and other art materials , on which pictures are written, engravings and etchings are printed, they are usually specially processed materials of woodworking (cardboard, hardboard) and weaving (canvas) industries. In addition, waste is used as a material for these purposes. wood(first) and linen or the like. (second). In this case, the canvas is coated with a special composition (primed) before applying paints to it.

3. photographic materials (negative, positive) are used for media such as photographic plate, photographic film, film or filmstrip, transparencies or slide, microfilm or microfiche. For these media, films are mainly used on cellulose, polyester base.

4. gramophone record usually made by pressing plastic mass(vinyl). Represents a round disk, on the surface of which concentric (spiral) grooves are applied, running from the outer side of the disk to its center. Discs differ in diameter, recording speed, number of audio channels and content.

To sizeThese disks are divided into three types:

1. "Giant" - 30 cm in diameter (playing time of one side 25-30 minutes).

2. "Grand" - with a diameter of 25 cm (the playing time of one side is 12-15 minutes).

3. "Mignon" - 17.5 cm in diameter (playing time of one side is 6-8 minutes).

By disk rotation speed gramophone records come in 4 types: 16, 33, 45, 78 rpm.

By record type records are divided into: monophonic, stereophonic and long-playing. Long-playing records have narrower grooves and a smaller distance between them (pitch) than conventional records, which allows for longer playing times. Stereo records contain a two-channel recording (left and right channel along the left and right walls of the groove).

5. Hologram - a plate with lithium niobate crystals or a photopolymer film. Holographic memory, unlike CD technology, represents the entire volume of the storage medium of the carrier, while data elements are accumulated and read in parallel. It allows you to place 1 TB (trillion bytes) in a crystal the size of a sugar cube, that is, information with a volume of more than 1000 CDs. Modern holographic storage devices are called HDSS (holographic data storage system).

6. Magnetic tapes in audio and video cassettes, streamers, magnetic disks in PC floppy disks are made of synthetic materials with a magnetic layer (usually iron oxide) on the lavsan or vinyl basis. Disks in HDD are made of light metal (aluminum) or glass and coated on both sides with a magnetic layer.

7. Magneto-optical disks (MO disks) are placed in a plastic case. Recording by a laser with a temperature of about 200°C on the magnetic layer occurs simultaneously with a change in the magnetic field. This property provides high reliability of storage of recorded information.

8. V optical (laser) disks - CDs for audio-video recordings and other machine-readable information. The carrier material in a CD is polycarbonate, polyvinyl chloride or special glass with a reflective (sprayed) aluminum layer. Use optical recording method. They can be classified as a medium, a carrier of various text, digital, sound and video recordings, multimedia, etc.

Distinguish: AudioCD CD-ROM, CD-R, CD-R W and others.

CD- ROM. The CD-ROM replication technology is similar to the production of gramophone records - printing (stamping) from matrices. In the process of writing, the laser acts on the photoresist, leaving lines-marks on it. The photoresistive layer is developed and metallized. Then, using the electroforming method, a second one is made from the original - completely metal, and intermediate copies are created from it by stamping. Many matrices are created from them, from which the manufactured products are replicated on CDs.

CD-Rused for a single laser recording or a single recording with the addition of several recordings to the same disc in the form of sessions (recording).

CD-RWallow you to repeatedly (hundreds and a thousand times) erase and write information to them.

Compact discs are distinguished by high recording density (about 300 thousand pages of text in A4 format), the ability to quickly search for information stored on them (a few milliseconds), and the durability of the media (tens of years).

This carrier has up to four recording layers and a capacity from units (4.7) to tens (17) GB. In this case, the duration of the recording increases to 8 hours. Increasing the information capacity of the disk is achieved through the use of a laser with a shorter wavelength of radiation (0.635-0.66 instead of 0.78 microns), as well as video data compression technology in standards MPEG , which made it possible to increase the density of data recording on these disks and the speed of reading information from them. For example, the digital video data rate is 1.3 Mbps, which provides high quality video (better than VHS ), and on the monitor is better than on the television receiver.

There are many varieties of compact discs that differ in the use of various media materials, recording methods, etc. Among the new devices, it should be noted “blu- rayDisc».

Blu-ray Disc Technology developed at the end of 2001. Since February 2002, its specification has been supported by a number of well-known foreign companies. Disks with a diameter of 12 mm have a capacity of 23.3; 25 and 27 GB, the thickness of the transparent protective layer is 0.1 mm, and the track width is 0.32 mm, which allowed not only to provide more capacity, but also to increase the read / write speed. The base speed of devices for working with these drives (1x) is 36 Mbps (5.5 MB/s). Recall that at DVD this parameter is 1.3 Mb / s, and for CD – 150 KB/s respectively. According to the developers, these discs are well suited for recording television and video programs broadcast in digital format.

9. Flash -memory - solid-state built-in and replaceable thin memory wafer made of semiconductor materials. Contains a flash memory chip with exposed contacts. These cards draw power from the devices they connect to. The amount of stored information is from 16 MB to 4 GB.

Information is recorded and stored on different media by different methods. Forms of storage and storage media are presented in table. 5-2.

Table 5-2

Forms of storage and storage media

Information form	Information carrier	Information recording method
Mechanical	plate	analog
Optical	paper	sign-symbolic
	film film	analog
	laser audio disc CD-A	analog
	laser disc CD - ROM , DVD	digital
Magnetic	audiovisual film	analog
	floppy disks	digital
	hard drives	digital

The possibilities of using various media and their materials for recording and using even one type of data are very diverse. So, text can be recorded on almost any media, presented as a static or dynamic image on the following media materials (Fig. 5-2).

Rice. 5-2. Materials of text information carriers

Sound, recorded on various media, is an important component of various funds and collections. Such media may be provided to users and used for official purposes; be stored for a short time or for a long time, etc.

Audio recordings and gramophone records, available in one copy, are not recommended to be issued to users at home. It is better for information services that serve users to purchase sound recordings in at least two copies in order to keep one of them in the reserve fund. If they contain records in one single copy, then it is advisable to rewrite them, for example, on a magnetic tape, floppy disk or disk to replenish the main fund of sound recordings provided to users, and store the first copy in the reserve fund.

The sound is recorded and stored on the storage media shown in Fig. 5-3.

Rice. 5-3. Audio media

If there are high-quality tape recorders or music centers in the information services serving users, the purchased one copy of the sound recording on magnetic tape is stored in the reserve fund, and copies are made from it on their own, which are issued to users.

Static video information obtained in the process of photographing and processing photographic materials (development and printing). Until the mid-1930s, many photographic materials were produced on a cellulose-nitrate basis (nitrate-based film was produced until 1951). In the late 1940s, silver-free powder photography appeared - xerography. In the 1950s, a way to create short-lived copies appeared - thermography.

The type of photography is micrography. Photographic recording allows documents to be stored in the form of microfilm and microfiche, i.e. microforms - microcarriers. Microcarriers are photographically reduced copies by tens and hundreds of times from various originals (manuscripts, drawings, drawings, printed texts, etc.).

Microforms serve as a protective copy of the original. The basis of micrographic film is plastic bases. It is the most important factor determining the durability and safety of the film. The insurance (archival) funds store reference negatives of the first generation (master negatives), which are used in the microfilming of manuscripts, archival materials and rare publications.

Vesicular, photothermoplastic and electrophotographic films are also used in micrography. They are mainly used for working microforms. Microcarriers are used in information centers, archives, libraries, research, design and other institutions.

Relatively cheap and widespread type of audio-video data carrier are magnetic tapes and disks. They are convenient to use. Reliable methods have been developed for the physical protection of magnetic media from damage, errors during reading, and spontaneous disappearance of data. Thus, it is recommended to carefully wind, clean and rewind magnetic tapes in both directions every six months, and copy every 12 months. The UK Government Computer Agency believes that magnetic tapes can be stored for up to three years under normal conditions, but recommends checking samples every 18 months.

A modern way of recording audiovisual data presented to users is to "digitize" them, followed by recording them on CDs. Work on creating a method for digital recording and playback of sound has been intensively carried out since the early 70s of the twentieth century. At the end of 1982, the first CDs appeared on sale.

The life of CDs will be significantly reduced by excessive heat, humidity, or direct sunlight. Therefore, it is recommended to store discs in a cool, dark and dry place.

The memory of any phone, computer or camera is not unlimited, therefore, in order to use your device more efficiently, it makes sense to purchase such a portable storage medium as a flash card. In addition, its convenience lies in the fact that you can view files anywhere, even if your gadget is not around. Over time, memory cards have been modified and have undergone a number of changes. At the moment, for a certain type of device, there is a flash drive model.

What is a flash card

A few years ago, flash drives did not yet have such a distribution in everyday life outside of offices and serious institutions. Over the years, the popularity of flash drives has increased significantly, and the average user can no longer imagine their activities without them. A flash drive is a miniature box with microcircuits hidden in it and a certain type of connectors.

The purpose of the USB flash drive is to accumulate information inside itself and provide access to it at any time via USB or using a special adapter. You can store documents of any format, photos, music and videos on a memory card. How much will fit on a flash drive depends on its volume: it can be so small that it will only allow you to record a few photos in good quality.

Principle of operation

For all its seeming simplicity, the flash drive device is fraught with many secrets unknown to the average user. Inside the compact box there is a complex microcircuit, with the help of which it is possible to record, store and then read information. Flash memory is the basis of these devices and it is represented by such a component as a floating gate transistor. Methods for connecting to an array of cells for memory cards differ, due to which chips of the NOR and NAND types stand out. Differences noticeable to the user are manifested in the speed of writing, erasing and reading.

Kinds

Not only the intricate design of the memory card can classify these portable devices. Flash drives have other, more important, parameters with which you can combine them into groups:

• Outer shell. There are flash drives with a USB connector designed to be connected to a computer or other devices with a suitable input. In addition to them, there are mini- and even micro-memory cards that are actively used, for example, for photographic equipment or mobile phones.
• Capacity. Capacity plays a role, so it’s better to immediately choose a flash drive with the right number of gigabytes, since a wide range will allow you to do this.
• File system. The FAT family is often found in small flash media. If we are talking about more capacity, then in such cards you will find an NTFS system that has more advanced features.

Flash drive

The non-volatility of memory cards captivates users who want to save their files and be able to access them at any time. Due to the variety of digital media and information technology in a retail or online store, the average user who chooses a flash drive for personal use can simply get lost. Initially, you need to decide on the purpose of the purchase and how to use the flash drive.

SD

There are many flash devices on the market with similar names that can make the average user confused about them. The Secure Digital Memory Card is almost the first memory card standard introduced in 1999. At the moment, such flash devices are still used in certain types of equipment and you can buy an SD card in most stores. A distinctive feature of such a card is its small volume: the minimum is 8 MB and the maximum is 4 GB.

• Name: Transcend TS128MSD100I.
• Price: 650 rubles.
• Characteristics: the card has a capacity of 128MB, has a good speed of copying and reading, there is a mechanical write blocker on the side.
• Pros: compatible with most devices, inexpensive.
• Cons: small capacity.

There are more expensive flash drives, where the increase in cost is due to higher capacity or other parameters:

• Name: Apacer Secure Digital Card.
• Price: 1900 rubles.
• Characteristics: the volume of the flash media is 2GB, belongs to class 10.
• Pros: good speed, average capacity.
• Cons: None found.

microSD

Tiny devices often also need more memory. The MicroSD flash drive is the smallest card currently in existence. For it, you can find adapters on sale, with which you can open a flash drive, for example, through a laptop. Most of the card options are similar, but there is a choice:

• Name: Kingston SDC/2GB.
• Price: 200 rubles.
• Specifications: Comes with a 2GB MicroSD card and an adapter for it.
• Pros: cheap, the presence of an adapter.
• Cons: small volume, slow data transfer rate.

Alternatively, in about the same price range, you can consider the following option:

• Name: Qumo MicroSD.
• Price: 250 rubles.
• Characteristics: volume - 4GB, the manufacturer provides a flash drive complete with an adapter.
• Pros: low price, good speed.
• Cons: high percentage of marriage in batches.

SDHC

Technological progress does not stand still and SD cards gradually began to change. Most of the parameters of these flash drives SDHC inherited. However, the huge difference is the significant increase in storage capacity. The maximum you can write to such a flash drive is 32GB. Many well-known companies that produced SD cards included SDHC in their lines:

• Name: SanDisk Extreme Pro SDHC UHS Class 1.
• Price: 1000 rubles.
• Characteristics: volume - 8GB, read and write speed - 90-95 Mb / s, durable case.
• Pros: High speed, card shock resistance, good value for money.
• Cons: None found.

Often, for about the same price, you can buy a larger flash drive. The catch lies in the lower class, which will necessarily affect the data transfer rate:

• Name: Kingston SD4.
• Price: 1200 rubles.
• Characteristics: volume - 32GB, class - 4.
• Pros: reliable manufacturer, large volume, reasonable price.
• Cons: average speed.

SDXC

A new compact flash media standard was developed in 2009. Unlike their counterparts, SDXC cards use the exFAT file system. The volume of flash drives increases to unprecedented sizes at that time, and a small card gets the ability to hold information up to 2TB. Most modern devices already know how to work with this type of card.

• Name: Silicon Power Superior Class 10 UHS-I U3.
• Price: 2900 rubles.
• Characteristics: it is possible to write up to 64GB of information, the read speed is 90Mb / s, the write speed is 2 times lower.
• Pros: large capacity.
• Cons: None found.

For professional photographic equipment, where quality directly affects the file weight, it is better to immediately choose a larger card:

• Name: Kingston SDA10.
• Price: 14,000 rubles.
• Characteristics: volume - 512GB, write speed is twice as low as read speed, belongs to class 10.
• Pros: excellent quality of work, proven manufacturer.
• Cons: high price.

How to choose a flash card

In Moscow and St. Petersburg, the choice of flash drives is very wide. If smaller cities cannot boast of such an assortment, then their residents always have the opportunity to order a memory card via the Internet with delivery by mail. It does not matter whether it is a flash drive for a phone or a computer, the main thing is to focus on the necessary parameters. Pay attention to the following criteria:

• Volume. It is important that the amount of information that you plan to write down is placed on the card.
• Format. Among the available types of flash media, you must select the one that fits your device.
• Transfer rate. So that the device to which the flash drive will be attached does not slow down, give preference to memory cards with optimal speed.
• Manufacturer. There are several key leading brands in the flash drive segment - it's best to choose from them.

For phone

When the place on the smartphone starts to run out rapidly, the memory needs to be expanded. Not every memory card for a phone can be suitable. It must be understood that since the device is miniature, then the flash drive will be similar. The smallest are MicroSD, so they will be suitable for phones. There are two options: MicroSDHC and MicroSDXC, which, like their full-length counterparts, differ only in size and supported file system.

If we talk about laptops, then most modern models are equipped with built-in adapters for reading cards. For those computers that do not have them, you can purchase a separate card reader. By default, all flash drives of the SD family are read, and an adapter is required for micro cards. This is very convenient when transferring files from one device to another. For example, in order to free up space on the flash drive from the camera, pictures can be quickly copied to a computer.

Video

A slang word very often used in circulation - flash drive, so firmly entrenched in everyday life that many have forgotten how to properly call this device, while others do not know at all.

This miniature device is used to copy, store and transmit digitized information. Correct device name:

USB indicates a way to connect a flash drive to other devices through special ports, and flush reports that the functions of storing and copying information are implemented using non-volatile flash memory on semiconductors.

The advantages of flash drives are in their small size, quiet operation and shock resistance.

Electronics sellers in stores use the name flash drive.

Officially flash drive It is called USB flash drivequot ;, as it is a storage device that uses flash memory as a medium and connects to a computer or reader via USB.

• USB flash drive

  So Wikipedia officially calls the flash drive.

  By the way, I would have the word and " USB flash drive" recommended writing precisely through the letter equot ;. The same Wikipedia gives the following official English name for this device: USB flash drive". In this case, we are interested in the word flash. It is from him that the word flash drivequot ;. The English language also has the word flashquot ;, which has nothing to do with a flash drive.

The word flash drive - this is the abbreviated name flash cardsquot ;. You can also find the names memory card and USB flash drive is a storage medium converted to flash memory (you can read more about flash memory here), so the main characteristic of a flash card is the amount of memory.

The word flash drive is very widely used in everyday life, most people do not even know the correct name of this device. In full name:

The word flash means that information is stored using Flash memory, a USB connection to a computer.

A flash drive is officially considered to be a USB flash drivequot ;, which is able to save the information copied to it and provides the ability to repeatedly transfer data from it to other electronic devices.

A flash drive is properly called a USB flash drive. USB is called because it plugs into this port on the computer. It is called a drive because it can store information and conveniently carry a large volume with you. It is necessary to handle it carefully and stop working with it before pulling it out of the connector.

What is the correct name flash drive, which has become so familiar to everyone - in fact, few people think about it. Other names that are used quite often are memory stick or USB memory stick, flash (or flash) card, or flash/flash drive.

In this case, the correct name of the flash drive is:

a device with removable media or flash memory or just a memory card

Well, for us it is accepted this is " call a flash drive, it is a flash drive, they just call it correctly " USB flash drive ", and USB stands for " Universal serial bus", also called briefly " flash, flash drive, flash drive

The flash drive is called flash card or flash memory card. Although in online stores this device is called USB stick, so this is probably more correct.

There is also just a memory card, but this is somewhat different, those memory cards are used for mobile phones, although the principle of storing information seems to be the same for them: a flash method of remembering. Now they also began to make BIOS on nm.

A USB flash drive or simply a flash drive is a data storage device based on flash memory and a USB interface for physical connection to a computer or other device.

General introduction to the USB flash drive

USB flash drives are typically removable and rewritable, and are smaller than optical discs. The purpose of a USB flash drive is the same as that of obsolete floppy disks and optical disks, i.e. for storing information, backups and transferring files. They are smaller than their counterparts, faster and, like SSDs, have no moving parts. At one time, floppy disks were abandoned due to the impact on them of electromagnetic interference and low capacity in favor of USB media.

USB flash drives are supported by all modern operating systems: Windows, Linux and OS X. USB flash drives can work without problems with game consoles, audio-video players, as well as on most types of computers.

Such a flash drive consists of a small printed circuit board with connected elements and a USB plug protected from external influences, a case (made of metal, plastic, there are devices with rubberized cases and leather cases, which is suitable for always carrying with you or as a key fob) .

The USB plug may be a secure cover or have the often present retractable housing mechanism to provide additional protection. A connection type like USB allows you to connect to anything that has a compatible port. USB flash drives are powered by the connection, and other devices, including portable audio-video players, use this ability to charge. Most of them can be used as a flash drive, only with a battery for battery life.

The advent of the USB flash drive

The invention of USB flash drives was patented by the inventors of the Israeli company M-Systems: Dov Moran, Amir Ban and Oron Ogdan in April 1999, but this device looked different from modern USB flash drives. Later, on September 13, Shimon Shmueli had already patented a sample that accurately describes the USB flash drive that is used today. Due to controversy and controversy over the clarification of the authorship of a given medium, litigation was not uncommon.

The first such storage devices became available in 2000, the volume was equal to 8 megabytes, which is about 5 times more than the floppy disks used at that time. Already by 2013, most flash drives had a USB 2.0 interface with a possible speed of 480 Mbps.

Although the appearance of USB 3.0 flash drives was announced back in 2008, they became available to the consumer only in 2010. USB 3.0 has the advantage of 5 Gb/s data transfer rate and is backwards compatible with USB 2.0. Most modern computers have at least one such port. But already in March 2015, the production of USB flash drives was announced, with USB 3.1 plugs providing even greater data transfer speed.

Using USB flash drives

The most common use of flash drives is to carry and store any kind of files. Often flash drives are used to update the BIOS or UEFI of motherboards.
Most modern PCs support not only installing an operating system using a bootable flash drive, but the ability to boot from a USB device, which allows the operating system to boot from a flash drive. This configuration is often called Live USB among users. This feature will help not only in cloning the operating system and its further transfer to a similar computer, perform file manipulation without loading the main OS and fight against malware.
The USB storage device supports encryption, which is important for the safe storage of information and does not lose relevance when backing up. Flash drives can be used as a key to activate (USB Keys) applications.

USB flash drive capacity

As mentioned earlier, since 2000, flash drives have had a capacity of 8 megabytes. Later, the maximum volumes increased by 2 times (16 MB, 32 MB, 64 MB, etc.). Although the possible volumes are already over a terabyte, USB flash drives from 8 to 120 gigabytes are still a success with buyers.

How a flash drive works and its main components

The most common flash drive has a Standard-A USB interface, but there are also those that have micro-USB interfaces, such standardization can facilitate transfer between different devices. A small printed circuit board is hidden under the case, on which integrated circuits and power circuits are placed. As a rule, the most ordinary flash drive consists of five parts:

1. A plug, most often it is A-USB, a physical connection to a computer is provided using the USB interface;
2. Microcontroller with a small amount of RAM and ROM;
3. NAND flash memory chips that store user information;
4. Quartz (crystal) oscillator - produces a clock frequency of 12 MHz (generates clock pulses);
5. The case, which is usually made of plastic or metal, thereby protects the electronics from mechanical stress.

Non-essential components may include various LEDs that flash when accessing a USB flash drive, switches that can block or unblock access. A cover that covers the USB plug, it is not required, but a kind of protection for the plug. Some USB flash drives have a hole through which makes them like a key fob or for attaching a cord to it. There are also flash drives that have memory expansion functions, to which you can add an SD card, as well as readers (card readers).

Dimensions and appearance of the flash drive

The usual USB flash drive usually has an elongated shape, but some manufacturers draw the attention of their customers to the unusual look of their USB flash drive, or rather an unusual case that can be so bulky that it creates some difficulties when connecting devices. This is due to the fact that USB connectors on a computer are often very close to each other, it turns out that two ports can be occupied by one USB flash drive. Flash drives are often integrated into other technical solutions, such as clocks, pens, etc. Shapes, colors and images are only limited by the imagination.

Flash drive and its file system

Most flash drives are natively file system FAT32 or ExFAT, this allows you to use the flash drive on almost any device with USB support, however, the file system can be any supported operating system.

Read and write speed

Reading and writing data speeds are measured in megabytes per second (Mb/s), moreover, the read speed is usually higher than the write speed, and the characteristics declared by the manufacturer, obtained under optimal conditions, may also differ from the actual ones. The version of the USB interface also affects the speed of work.

What does USB flash drive service depend on?

Cheap flash drives are usually designed using multi-level memory cells, with up to 5000 sector write and erase cycles. Drives designed using single-level memory cells will be able to withstand 2 times more write cycles. It all depends on the frequency of using a flash drive, your descendants will also be able to use it, if you use it extremely rarely.

The service life also depends on the quality of the flash drive itself. Often you can buy a fake that does not meet the requirements of the original. In such USB media, the amount of memory may differ from the declared ones, even if the standard check shows the face value, then after filling a part or after formatting, the space may disappear. Supported interfaces may also differ from those declared: the declared USB 3.0 may eventually work as 2.0.

What is a flash drive is a modern device for storage, transfer, encryption, backup and even more functionality. All this makes life easier not only for a PC user, but also for a professional. You can often find a USB flash drive with the logo of some organization, this is quite a good advertisement, the main thing is to use only high-quality media, this will make it possible to save all the necessary information for many years.

Flash card Request redirected here Flash cards. On the topic "Flash cards".

Specifications

The speed of some devices with flash memory can reach up to 100 Mb / s. In general, flash cards have a wide spread of speeds and are usually labeled at the speeds of a standard CD drive (150 KB/s). So a speed of 100x means 100 × 150 KB/s = 15,000 KB/s = 14.65 MB/s.

Basically, the volume of a flash memory chip is measured from kilobytes to several gigabytes.

To increase the volume in devices, an array of several chips is often used. By 2007, USB devices and memory cards ranged in size from 512 MB to 64 GB. The largest volume of USB devices was 4 TB.

File systems

The main weak point of flash memory is the number of rewrite cycles. The situation worsens also due to the fact that the OS often writes data to the same place. For example, the file system table is frequently updated, so that the first sectors of memory will use up their supply much earlier. Load balancing allows you to significantly extend the life of the memory.

To solve this problem, special file systems were created: JFFS2 and YAFFS for GNU/Linux and Microsoft Windows.

SecureDigital and FAT.

Application

Flash memory is best known for its use in USB flash drives. USB flash drive). The NAND type of memory is mainly used, which is connected via USB via the USB mass storage device (USB MSC) interface. This interface is supported by all operating systems of modern versions.

Due to their high speed, volume and compact size, USB flash drives completely replaced floppy disks from the market. For example, the 2003 company stopped making computers with a floppy disk drive.

At the moment, a wide range of USB flash drives is produced, in different shapes and colors. There are flash drives on the market with automatic encryption of the data written to them. The Japanese company Solid Alliance even produces flash drives in the form of food.

There are special GNU/Linux distributions and versions of programs that can run directly from USB sticks, for example, to use their applications in Internet cafes.

Windows Vista technology is able to use a USB flash drive or special flash memory built into the computer to increase performance. Memory cards are also based on flash memory, such as SecureDigital (SD) and Memory Stick, which are actively used in portable technology (cameras, mobile phones). Together with USB drives, flash memory occupies a large part of the portable storage media market.

NOR type of memory is more often used in BIOS and ROM memory of devices such as DSL modems, routers, etc. Flash memory allows you to easily update the firmware of devices, while the write speed and volume are not so important for such devices.

Now the possibility of replacing hard drives with flash memory is being actively considered. As a result, the computer turns on faster, and the absence of moving parts will increase the service life. For example, the XO-1, a “$100 laptop” that is being actively developed for third world countries, will use 1 GB flash memory instead of a hard drive. Distribution is limited by a high price per GB and a shorter shelf life than hard drives due to the limited number of write cycles.

Types of memory cards

There are several types of memory cards used in portable devices:

MMC (MultiMedia Card): MMC card is small, 24×32×1.4 mm. Developed jointly by SanDisk and Siemens. The MMC contains a memory controller and is highly compatible with various types of devices. In most cases, MMC cards are supported by devices with an SD slot.

RS-MMC (Reduced Size MultiMedia Card): A memory card that is half the length of a standard MMC card. Its dimensions are 24 × 18 × 1.4 mm, and its weight is about 6 g, all other characteristics do not differ from MMC. An adapter is required to ensure compatibility with the MMC standard when using RS-MMC cards. DV-RS-MMC (Dual Voltage Reduced Size MultiMedia Card): DV-RS-MMC memory cards with dual power supply (1.8V and 3.3V) have lower power consumption, which will allow your mobile phone to work a little longer. The dimensions of the card are the same as those of RS-MMC, 24×18×1.4 mm. MMCmicro: Miniature memory card for mobile devices with dimensions of 14×12×1.1 mm. An adapter must be used to ensure compatibility with the standard MMC slot.

SD Card (Secure Digital Card): Supported by Panasonic and : Older so-called Trans-Flash SD cards and newer SDHC (High Capacity) cards and their readers differ in the maximum storage capacity limit, 2 GB for Trans-Flash and 32 GB for High Capacity (High Capacity). SDHC readers are backwards compatible with SDTF, meaning an SDTF card will be read in an SDHC reader without problems, but only 2 GB of the larger SDHC capacity will be seen in an SDTF device, or it will not be read at all. It is assumed that the TransFlash format will be completely superseded by the SDHC format. Both sub-formats can be presented in any of the three physical formats. sizes (Standard, mini and micro). miniSD (Mini Secure Digital Card): They differ from standard Secure Digital cards in smaller dimensions of 21.5×20×1.4 mm. An adapter is used to ensure the operation of the card in devices equipped with a conventional SD slot. microSD (Micro Secure Digital Card): are currently (2008) the most compact removable flash memory devices (11×15×1 mm). They are used primarily in mobile phones, communicators, etc., because, due to their compactness, they can significantly expand the memory of the device without increasing its size. The write protection switch is placed on the microSD-SD adapter.