A USB flash drive

USB flash drives are NAND-type flash memory data storage devices integrated with a USB (universal serial bus) connector. They are also called pen drives.They are typically small, lightweight, removable and rewritable. (USB Memory card readers are also available, whereby rather than being built-in, the memory is a removable Flash memory card housed in what is otherwise a regular USB flash drive, as described below.) Science fiction is a form of speculative fiction principally dealing with the impact of imagined science and technology, or both, upon society and persons as individuals. ... Jump drive is a name given to a method of traveling faster than light in science fiction. ... Image File history File links USB_flash_drive. ... Image File history File links USB_flash_drive. ... A USB flash drive. ... A USB flash drive. ... Many different consumer electronic devices can store data. ... Note: USB may also mean upper sideband in radio. ... Four major types of memory cards (from left to right: CompactFlash, Memory Stick, Secure Digital, and xD. A memory card or flash memory card is a solid-state electronic flash memory data storage device used with digital cameras, handheld and Mobile computers, telephones, music players, video game consoles, and other... A card reader is a device used for communication with a smart card or a flash memory card. ...

USB flash drives offer potential advantages over other portable storage devices, particularly the floppy disk. They are more compact, faster, hold more data, and are more reliable due to their lack of moving parts, and have a more durable design. Additionally, it has become increasingly common for computers to ship without floppy disk drives. USB ports, on the other hand, appear on almost every current mainstream PC and laptop. These types of drives use the USB mass storage standard, supported natively by modern operating systems such as Windows, Mac OS X, Linux, and Unix. A floppy disk is a data storage device that is composed of a disk of thin, flexible (floppy) magnetic storage medium encased in a square or rectangular plastic shell. ... The USB mass storage device class is a set of computing communications protocols defined by the USB Implementers Forum that run on the Universal Serial Bus. ... 1. ... Mac OS X (IPA: ) is a line of graphical operating systems developed, marketed, and sold by Apple Inc. ... This article is about operating systems that use the Linux kernel. ... Filiation of Unix and Unix-like systems Unix (officially trademarked as UNIX®, sometimes also written as or ® with small caps) is a computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs including Ken Thompson, Dennis Ritchie and Douglas McIlroy. ...

Note that with nothing being mechanically driven in a flash drive, the name is actually a misnomer. The motivation to call it a "drive" comes from the fact that it is a replacement for the mechanically driven floppy disk. This article does not cite any references or sources. ...

A flash drive consists of a small printed circuit board typically in a plastic or metal casing. This makes the drive sturdy enough to be carried about in a pocket, for example as a key fob, or on a lanyard. Only the USB connector protrudes, and it is typically protected either by a removable cap or by retracting into the body of the drive. Most flash drives use a standard type-A USB connection allowing them to be connected directly to a port on a personal computer. Part of a 1983 Sinclair ZX Spectrum computer board. ... A wooden key fob made by aarikka of Finland A key fob is a decorative item many people often carry with their keys, on a ring or a chain, for ease of tactile identification, to provide a better grip, or to make a personal statement. ... A lanyard (sword knot) fixed to an infantry sword handle A lanyard, also spelled laniard, is a rope or cord often worn around the neck or wrist to carry something. ... USB redirects here. ...

To access the data stored in a flash drive, the drive must be connected to a computer, either by plugging it into a USB host controller built into the computer, or into a USB hub. Flash drives are active only when plugged into a USB connection and draw all necessary power from the supply provided by that connection. However, some flash drives, especially high-speed drives, may require more power than the limited amount provided by a bus-powered USB hub, such as those built into some computer keyboards or monitors. These drives will not work unless plugged directly into a host controller (i.e., the ports found on the computer itself) or a self-powered hub. A USB hub A USB hub is a hub device that allows many USB devices to be connected to a single USB port. ...

Technology

Flash memory is actually a combination of a number of older technologies, the low cost, low power consumption and small size being made possible by recent advances in microprocessor technology. The memory storage is based on earlier EPROM technology. The first EPROMS had very limited capacity, were very slow for both reading and writing, required complex high-voltage drive circuitry, and could only be re-written by first exposing them to short-wavelength ultraviolet light, which would erase the entire contents. A microprocessor is a programmable digital electronic component that incorporates the functions of a central processing unit (CPU) on a single semiconducting integrated circuit (IC). ... EPROM. The small quartz window admits UV light during erasure. ...

A later variant, the EEPROM, could be erased electrically without the need for UV light, but as with the original versions, it was still a total erasure. (These were widely used for storing the BIOS firmware in PCs.) An EEPROM (also called an E2PROM)[] or Electronically Erasable Programmable Read-Only Memory, is a non-volatile storage chip used in computers and other devices to store small amounts of volatile (configuration) data. ...

Later EEPROMS were developed where the erasure region was broken up into smaller "fields" that could be erased individually without affecting the others. Altering the contents of a particular memory location involved first copying the entire field into an off-chip buffer memory, erasing the field, and then re-writing the data back into the same field, making the necessary alteration to the relevant memory location while doing so. This required considerable computer support, and PC-Based EEPROM flash memory systems often carried their own dedicated microprocessor system. Flash drives are more or less a miniaturized version of this.

The development of high-speed serial data interfaces such as USB for the first time made serially accessed storage memory systems viable, and the simultaneous development of small, high-speed, low-power microprocessor systems allowed this to be incorporated into extremely compact systems. Serial access also greatly reduced the number of electrical connections required for the memory chips, which has allowed the successful manufacture of multi-gigabyte capacities. (Every external electrical connection is a potential source of manufacturing failure, and with traditional manufacturing, a point is rapidly reached where the successful yield approaches zero). Note: USB may also mean upper sideband in radio. ... This article is about the unit of measurement. ...

Modern flash memory systems are accessed very much like hard disk drives, where the controller system has full control over where information is actually stored. The actual EEPROM writing and erasure processes are, however, still very similar to the earlier systems described above.

Many low-cost MP3 Players simply add extra software to a standard flash memory control microprocessor so it can also serve as a music playback decoder. Most of these can also be used as a conventional flash drive. A digital audio player (DAP) is a device that stores, organizes and plays digital music files. ...

History

First invention and sale

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Flash drive with retractable USB connector

Several companies claim to be the first to have invented the USB Flash Drive. Trek was the first company to sell a USB Flash Drive (ThumbDrive) in early 2000. However, their patent does not describe the USB Flash Drive; rather, it describes a very broad family of storage devices which could include the USB Flash Drive. Image File history File links Acap. ... Image File history File links Download high resolution version (1704x632, 154 KB) Summary Licensing File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): USB flash drive ... Image File history File links Download high resolution version (1704x632, 154 KB) Summary Licensing File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): USB flash drive ...

M-Systems (acquired by SanDisk in November 2006)^[1] had been working on a USB Flash Drive since 1998. They registered the domain www.diskonkey.com on October 12, 1999,^[2] indicating their intention to sell a product. In 2000 Dan Harkabi joined the M-Systems team and led the development of DiskOnKey. The industrial design was done by Ziba and the product won the IDEA award in 2001. M-Systems' patent rigorously describes the USB Flash Drive and its implementation. M-Systems was a Nasdaq-listed Israeli producer of flash storage memory founded in 1989, best known for its DiskOnChip 2000 line of products for embedded computers. ... SanDisk Corporation (NASDAQ: SNDK), formerly SunDisk, is an American multinational corporation which designs and markets flash memory card products. ... is the 285th day of the year (286th in leap years) in the Gregorian calendar. ... This article is about the year. ... This is the logo for the Industrial Design Excellence Awards 2005 The Industrial Design Excellence Awards is a program sponsored by BusinessWeek and IDSA (Industrial Designers Society of America), and is dedicated to fostering business and public understanding of the importance of industrial design excellence to the quality of life...

An IBM invention disclosure RPS8-1999-0201 (Sept. 99) by Shimon Shmueli et al. is the earliest known document to describe the USB-FD accurately and completely, and only the USB-FD. M-Systems manufactured the DiskOnKey for IBM, which in late 2000 was the first to sell the product in North America. The IBM 8 MB USB Memory Key became available December 15, 2000^{[3] [4]}. Shmueli later founded KeyNetica, the first company to patent and develop the concept that mobile and smart storage devices are all one needs for mobile computing. Current implementors of the concept are U3 (part of SanDisk, which also owns the original KeyNetica patent) and Ceedo. For other uses, see IBM (disambiguation) and Big Blue. ... Original equipment manufacturer, or OEM, is a term that refers to containment-based re-branding, namely where one company uses a component of another company within its product, or sells the product of another company under its own brand. ... ReBoot character, see Megabyte (ReBoot). ... U3 LLC is a joint venture that is backed by Sandisk and its subsidiary, M-Systems. ...

Trek Technology claims it was first to conceive and create the ThumbDrive.^[5]

Trek holds patents for the ThumbDrive in Japan, Taiwan, South Korea, the United Kingdom, New Zealand and Singapore.

Nevertheless, the ownership of the patent for this device has been widely disputed. According to The Straits Times' report, other companies started marketing similar devices. M-Systems, which was listed on NASDAQ at the time, called its gadgets DiskOnKey and Diskey. Electec is M-Systems' importer, and FE Global is its sole distributor in Singapore. Lexar can also lay claim to a pioneering USB flash drive product. In 2000 they introduced a Compact Flash (CF) card having an internal USB function. Lexar offered a companion card reader and USB cable that eliminated the need for a USB hub. NASDAQ in Times Square, New York City. ... CompactFlash (CF) was originally a type of data storage device, used in portable electronic devices. ...

Trek sued the four companies for infringing its patent. They counterclaimed, asking that Trek's patent be revoked as it was invalid.

The Singapore Court of Appeals confirmed the validity of Trek Technology's patent for its ThumbDrive, calling it "novel and inventive" in the decision published in The Straits Times. The city-state's highest court also quashed the plea of four companies—Israeli firm M-Systems Flash Disk Pioneers, Electec, FE Global Electronics and Singapore-based Ritronics Components—and ordered them to stop selling similar devices. The decision is expected to have a ripple effect on other similar lawsuits which the Trek group has pending in Britain, Japan and Taiwan.

Netac Technology of Shenzhen, China also holds a 1999 Chinese and 2004 US patent on USB flash technology which it has licensed to major manufacturers ^[6].

Second generation

Modern flash drives have USB 2.0 connectivity. However, they do not currently use the full 480 Mbit/s the specification supports due to technical limitations inherent in NAND flash. The fastest drives currently available use a dual channel controller, although they still fall considerably short of the transfer rate possible from a current generation hard disk, or the maximum high speed USB throughput. Note: USB may also mean upper sideband in radio. ... The megabit is a unit of information storage, abbreviated Mbit or sometimes Mb. ...

Typical overall file transfer speeds are about 3 MB/s. The highest current overall file transfer speeds are about 10-30 MB/s. Older, "full speed" 12 Mbit/s devices are limited to a maximum of about 1 MB/s.

Components

One end of the device is fitted with a single male type-A USB connector. Inside the plastic casing is a small printed circuit board. Mounted on this board is some simple power circuitry and a small number of surface-mounted integrated circuits (ICs). Typically, one of these ICs provides an interface to the USB port, another drives the onboard memory, and the other is the flash memory. A USB flash drive. ... A crystal oscillator is an electronic circuit that uses the mechanical resonance of a vibrating crystal of piezoelectric material to create an electrical signal with a very precise frequency. ... External links LEd Category: TeX ... Write protection, (also known as record protection) is a mechanism that prevents erasure of valuable data by the accidental recording or storing of new data. ... In electrical and mechanical trades and manufacturing, each of a pair of mating connectors or fasteners is conventionally assigned the designation male or female. ... Look up connector in Wiktionary, the free dictionary. ... Surface-mount components on a flash drives circuit board Surface mount technology (SMT) is a method for constructing electronic circuits in which the components (SMC, or Surface Mounted Components) are mounted directly onto the surface of printed circuit boards (PCBs). ... Integrated circuit of Atmel Diopsis 740 System on Chip showing memory blocks, logic and input/output pads around the periphery Microchips with a transparent window, showing the integrated circuit inside. ... A USB flash drive. ...

Essential components

There are typically four parts to a flash drive:

• Male type-A USB connector — provides an interface to the host computer.
• USB mass storage controller — implements the USB host controller and provides a linear interface to block-oriented serial flash devices while hiding the complexities of block-orientation, block erasure, and wear levelling, or wear balancing. The controller contains a small RISC microprocessor and a small amount of on-chip ROM and RAM.
• NAND flash memory chip — stores data. NAND flash is typically also used in digital cameras.
• Crystal oscillator — produces the device's main 12 MHz clock signal and controls the device's data output through a phase-locked loop.

Wear levelling (also written -levelling) is a technique for prolonging the service life of some kinds of eraseable computer storage media, e. ... Reduced Instruction Set Computer (RISC), is a microprocessor CPU design philosophy that favors a smaller and simpler set of instructions that all take about the same amount of time to execute. ... Read-only memory (usually known by its acronym, ROM) is a class of storage media used in computers and other electronic devices. ... RAM redirects here. ... Look up digital camera in Wiktionary, the free dictionary. ... A crystal oscillator is an electronic circuit that uses the mechanical resonance of a vibrating crystal of piezoelectric material to create an electrical signal with a very precise frequency. ... In synchronous digital electronics, such as most computers, a clock signal is a signal used to coordinate the actions of two or more circuits. ... A phase-lock, or phase-locked, loop (PLL) is an electronic control system that generates a signal that is locked to the phase of an input or reference signal. ...

Additional components

The typical device may also include:

• Jumpers and test pins — for testing during the flash drive's manufacturing or loading code into the microprocessor.
• LEDs — indicate data transfers or data reads and writes.
• Write-protect switches — indicate whether the device should be in "write-protection" mode.
• Unpopulated space — provides space to include a second memory chip. Having this second space allows the manufacturer to develop only one printed circuit board that can be used for more than one storage size device, to meet the needs of the market.
• USB connector cover or cap — reduces the risk of damage due to static electricity, and improves overall device appearance. Some flash drives do not feature a cap, but instead have retractable USB connectors. Other flash drives have a "swivel" cap that is permanently connected to the drive itself and eliminates the chance of losing the cap.
• Transport aid — In some cases, the cap or the main body contains a hole suitable for connection to a key chain or lanyard or to otherwise aid transport and storage of the USB flash device.

Top: jumper block on IDE hard drive with shunt; bottom: assorted shunts In electronics and particularly computing, a jumper is two or more connecting points that can be conveniently shorted together to set up or adjust a printed circuit board, such as a computers motherboard. ... “LED” redirects here. ... Write protection, (also known as record protection) is a mechanism that prevents erasure of valuable data by the accidental recording or storing of new data. ... Static electricity is a class of phenomena involving the net charge present on an object; typically referring to charged object with voltages of sufficient magnitude to produce visible attraction, repulsion, and sparks. ... A key fob is a decorative item which many people carry with their keys, on a ring or a chain, often to provide a better grip or to simply make a personal statement. ... A lanyard (sword knot) fixed to an infantry sword handle A lanyard, also spelled laniard, is a rope or cord often worn around the neck or wrist to carry something. ...

Size and style of packaging

Flash drives come in various, sometimes bulky or novelty, shapes and sizes, in this case ikura sushi

Some manufacturers differentiate their products by using elaborate housings, which are often bulky and make the drive difficult to connect to the USB port. Because the USB port connectors on a computer housing are often closely spaced, plugging a flash drive into a USB port may block an adjacent port. Such devices may only carry the USB logo if sold with a separate extension cable. Image File history File linksMetadata Download high resolution version (1066x892, 422 KB) Summary A USB flash drive in the shape of a piece of ikura sushi. ... Image File history File linksMetadata Download high resolution version (1066x892, 422 KB) Summary A USB flash drive in the shape of a piece of ikura sushi. ... This article is about fish eggs. ... Note: USB may also mean upper sideband in radio. ...

USB flash drives have been integrated into other tools commonly carried on one's person such as a watches, pens, and even the Swiss Army Knife; others have been fitted with novelty cases such as toy cars or LEGO bricks. The small size, robust nature and relatively low price of USB flash drives makes them an increasingly popular peripheral for case modding. Categories: Stub | Switzerland | Knives | Mechanical hand tools ... For other uses, see Lego (disambiguation). ... Modded PC case with light & switch, perspex window and fan hole Case modification (commonly referred to as Case modding) is the modification of a computer chassis (often just referred to as the case), or a video game console chassis. ...

Overweight or ill-fitting flash drive packaging can cause disconnection from the host computer. This can be overcome by using a short USB to USB (male to female) extension cable to relieve tension on the port. Such cables are USB-compatible, but do not conform to the USB 1.0 standard. ^{[7] [8]}

Common uses

System administration

Flash drives are particularly popular among system and network administrators, who load them with configuration information and software used for system maintenance, troubleshooting, and recovery.

Computer repair

Flash drives enjoy notable success in the PC repair field as a means to transfer recovery and antivirus software to infected PCs, while allowing a portion of the host machine's data to be archived in case of emergency.

Application carriers

Flash drives are used to carry applications that run on the host computer without requiring installation. U3, backed by flash drive vendors, offers an API to flash drive-specific functions. A free and open-source software platform known as Portableapps has also been developed to allow U3-like functionality on non-U3 drives. The Mozilla Firefox browser has a configuration for flash drives, as does Opera.^[9][10]

A Creative MuVo, a small solid-state digital audio player in a flash drive form

To boot operating systems

In a way similar to that used in LiveCD, one can launch any operating system from a bootable flash drive, known as a LiveUSB.

Windows Vista ReadyBoost

In Windows Vista, the ReadyBoost feature allows use of some flash drives to augment system memory.

Personal data transport

The most common use of flash drives is to transport and store personal files such as documents, pictures and video. Individuals also store medical alert information on MedicTag flash drives for use in emergencies and for disaster preparation.

Audio players

Many companies make solid state digital audio players in a small form factor, essentially producing flash drives with sound output and a simple user interface. Examples include the Creative MuVo and the first-generation iPod shuffle.

Music storing

USB key without player (called raw USB memory) can be played in a Hi-Fi or Radio-CD with a USB port. The file formats of the music in the USB key are MP3 or Ogg. In 2004, the German band WIZO made a recording industry first of releasing the "Stick EP", an album available only as a USB drive preloaded with high-bitrate MP3s. In 2007, a product known as the MU-STIK appeared in the market, offering a means of packaging music albums by containing all relevant digital audio/video data and a customizable player interface within a USB key.^[11]. Other releases on thumb drive include Not Here to Please You by Hadouken! and Icky Thump by White Stripes.

In arcades

In the arcade game In the Groove and more commonly In The Groove 2, flash drives are used to transfer high scores, screenshots, dance edits, and combos throughout sessions. While use of flash drives is common, the drive must be Linux compatible, causing problems for some players.

U3 LLC is a joint venture that is backed by Sandisk and its subsidiary, M-Systems. ... API may refer to: In computing, application programming interface In petroleum industry, American Petroleum Institute In education, Academic Performance Index This page concerning a three-letter acronym or abbreviation is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ... A USB drive, shown with a 24 mm US quarter coin for scale. ... Firefox redirects here. ... Opera is an Internet suite which handles common internet-related tasks, including visiting web sites, sending and receiving e-mail messages, managing contacts, and online chat. ... Download high resolution version (1600x1200, 300 KB)Image of a Creative MuVo digital audio player / keydrive A copy of nl:Afbeelding:Usb mp3. ... Download high resolution version (1600x1200, 300 KB)Image of a Creative MuVo digital audio player / keydrive A copy of nl:Afbeelding:Usb mp3. ... Wikipedia does not have an article with this exact name. ... Apple iPod, the best-selling hard drive-based player An embedded hard drive-based player (Creative ZEN Vision:M) An MP3 CD player (Philips Expanium) More commonly referred to as an MP3 player, a digital audio player or DAP is a portable, handheld digital music player that stores, organizes and... Gnoppix 0. ... In computing, booting is a bootstrapping process that starts operating systems when the user turns on a computer system. ... A live USB is a USB flash drive which can be booted from, often containing a Linux distribution. ... Windows Vista is a line of graphical operating systems used on personal computers, including home and business desktops, notebook computers, Tablet PCs, and media centers. ... This article or section is in need of attention from an expert on the subject. ... It has been suggested that this article or section be merged with Solid state drive. ... Apple iPod, the best-selling hard drive-based player An embedded hard drive-based player (Creative ZEN Vision:M) An MP3 CD player (Philips Expanium) More commonly referred to as an MP3 player, a digital audio player or DAP is a portable, handheld digital music player that stores, organizes and... Form factor refers to the linear dimensions and configuration of a device as distinguished from other measures of size (for example Gigabytes; a measure of storage size): in computing, form factor is used to describe the size and format of PC motherboards (see AT, ATX, BTX), but also of hard... Wikipedia does not have an article with this exact name. ... iPod shuffle is an iPod digital audio player designed and marketed by Apple Inc. ... High Fidelity is also the title of a book by Nick Hornby and a film directed by Stephen Frears, based upon Hornbys book. ... For other uses, see MP3 (disambiguation). ... Ogg is an open standard for a free container format for digital multimedia, unrestricted by software patents and designed for efficient streaming and manipulation. ... WIZO (IPA pronunciation: ) is a Punk Rock band from Sindelfingen, Germany. ... This article is about the English band. ... The White Stripes are a minimalist rock and roll duo from Detroit, formed in 1997. ... Centipede by Atari is a typical example of a 1980s era arcade game. ... In the Groove (abbreviated ITG) was a series of music video games that use a four-panel dance pad. ... In The Groove 2 is the sequel to Roxor Games 2004 arcade game In The Groove. ... A screenshot of the Wikipedia website, taken on Debian GNU/Linux running the X Window system A screenshot, screen dump, or screen capture is an image taken by the computer to record the visible items on the monitor or another visual output device, usually this is a digital image taken... This article is about operating systems that use the Linux kernel. ...

Strengths and weaknesses

Strengths

Flash drives are nearly impervious to the scratches and dust that were problematic for previous forms of portable storage, such as compact discs and floppy disks, and their durable solid-state design means they often survive casual abuse. This makes them ideal for transporting personal data or work files from one location to another, such as from home to school or office or for carrying around personal data that the user typically wants to access in a variety of places. The near-ubiquity of USB support on modern computers means that such a drive will work in most places. Look up scratch in Wiktionary, the free dictionary. ... CD redirects here. ... A floppy disk is a data storage device that is composed of a disk of thin, flexible (floppy) magnetic storage medium encased in a square or rectangular plastic shell. ...

Flash drives are also a relatively dense form of storage, where even the cheapest will store dozens of floppy disks worth of data. Many can hold more data than a CD (700 MB). Top of the line flash drives can store more data than a DVD. CD redirects here. ... ReBoot character, see Megabyte (ReBoot). ... DVD (also known as Digital Versatile Disc or Digital Video Disc) is a popular optical disc storage media format. ...

The power consumption of a typical flash drive is very low, much lower than that of the common alternative, the portable hard disk, due to there being no moving parts inside a flash drive. Portable hard disks, on the other hand, require several motors or actuators to rotate the disk platter, and move the read / write head. Consequently, the USB flash drive need not be as big, or heavy, allowing greater portability. A 3. ... The adjective motor refers to a motoneuron. ... An actuator is the mechanism by which an agent acts upon an environment. ... Close-up of a hard disk head resting on the disk platter. ... Microphotograph of a hard disk head. ...

Flash drives implement the USB mass storage device class, meaning that most modern operating systems can read and write to flash drives without any additional device drivers. The flash drives present a simple block-structured logical unit to the host operating system, hiding the individual complex implementation details of the various underlying flash memory devices. The operating system can use whatever type of file system or block addressing scheme it wants. Some computers have the ability to boot up from flash drives. An operating system (OS) is the software that manages the sharing of the resources of a computer and provides programmers with an interface used to access those resources. ... A device driver, or software driver is a computer program allowing higher-level computer programs to interact with a computer hardware device. ... For library and office filing systems, see Library classification. ... In computing, booting (booting up) is a bootstrapping process that starts operating systems when the user turns on a computer system. ...

Flash drives are much more tolerant of abuse than mechanical drives, but can still be damaged or have data corrupted by severe physical impacts. Improperly wired USB ports can also destroy the circuitry of a flash drive, a danger in home-built desktop PCs.

Some flash drives can retain their memory after being submerged in water ^[12], even through a machine wash. Leaving the flash drive out to dry completely before allowing current to run through it has been known to result in a working drive with no future problems.

Weaknesses

Like all flash memory devices, flash drives can sustain only a limited number of write and erase cycles before failure. Mid-range flash drives under normal conditions will support several hundred thousand cycles, although write operations will gradually slow as the device ages. This should be a consideration when using a flash drive to run application software or an operating system. To address this, as well as space limitations, some developers have produced special versions of operating systems (such as Linux) or commonplace applications (such as Mozilla Firefox) designed to run from flash drives. These are typically optimized for size and configured to place temporary or intermediate files in the computer's main RAM rather than store them temporarily on the flash drive. This article is about operating systems that use the Linux kernel. ... Firefox redirects here. ...

Most USB flash drives do not include a write-protect mechanism, although some have a switch on the housing of the drive itself to keep the host computer from writing or modifying data on the drive. Write-protection makes a device suitable for repairing virus-contaminated host computers without risk of infecting the USB flash drive itself. A computer virus is a computer program that can copy itself and infect a computer without permission or knowledge of the user. ...

A drawback to the small size is that they are easy to misplace, leave behind, or otherwise lose. This has led to the common practice of attaching flash drives to keychains or necklaces and lanyards.

In some USB flash drives, the USB interface is bigger than the storing body.

Comparison to other portable memory forms

Flash storage devices are often compared to other common, portable, swappable data storage devices, such as floppy disks, Zip disks, miniCD / miniDVD, CD-R/CD-RW and DVD-RW discs. A floppy disk is a data storage device that comprises a circular piece of thin, flexible (hence floppy) magnetic storage medium encased in a square or rectangular plastic wallet. ... Later (USB, left) and earlier (parallel, right) Zip drives (media in foreground). ... // Description MiniCDs are compact discs with a smaller form factor. ... There are two types of MiniDVD cDVD, which are 80-mm versions of the 120-mm DVD mini-DVD, which are standard CDs filled with the DVD-video format // cDVD A Mini-DVD-RAM with DVD Round Holder. ... This article does not cite any references or sources. ... Compact Disc ReWritable (CD-RW) is a rewritable optical disc format. ...

Following magnetic tape, the floppy disc was the first popular method of file transport; but floppies have been almost completely phased out due to their low capacity, low speed, and low durability. Virtually no new computers include floppy drives, but they do include USB ports—the Apple iMac was the first to ship this way. However, floppy disks are still being used because of their low cost, are often the easiest or only way to share files with older systems, are easily bootable, and because floppy drives can be added to new systems in external or internal forms. The original Bondi Blue iMac G3 was introduced in 1998. ...

Attempts to extend the floppy standard (such as the Imation SuperDisk) were not successful because of a reputation for unreliability and the lack of a single standard for PC vendors to adopt. The Iomega Zip drive enjoyed some popularity, but never reached the point of ubiquity in computers. Also, the larger sizes of Zip—now up to 750 MB—cannot be read on older drives. Unless one were to carry an external drive, their usefulness as a means of moving data was rather limited. The cost per megabyte was fairly high, with individual disks often costing US$10 or more. Because moving parts are involved and the material used for creating the storage medium in Zip disks is similar to that used in floppy disks, Zip disks have a high risk of failure and data loss compared to flash drives. Larger removable storage media, like Iomega's Jaz drive, had even higher costs for both drives and media, and as such were not pervasively adopted as a floppy alternative. An Imation USB Flash Drive and CD-R Imation Corporation NYSE: IMN is an American corporation spun off from 3M, with a worldwide presence that produces mainly data storage products. ... Also known as the LS-120 and the later variant LS-240, the SuperDisk was introduced by 3Ms storage products group (later known as Imation) circa 1997 as a high-speed, high-capacity alternative to the 90 mm (3. ... Iomega ZIP-100 Drive Logo An internal Zip drive. ... The Jaz drive was a removable disk storage system, introduced by the Iomega company. ...

CD-R and CD-RW are swappable storage media alternatives. Unlike Zip and floppy drives, DVD and CD recorders are now common in personal computer systems. CD-Rs can be written to only once. But CD-RWs are rated at up to 1,000 erase/write cycles, and modern NAND-based flash drives often last for 500,000 or more erase/write cycles. Optical storage devices also usually are slower than their flash-based counterparts. And, compact discs with a 12 cm diameter can be inconveniently large and, unlike flash drives, cannot fit into a pocket or hang from a key chain. There are smaller CD-R media such as business card CD-Rs, which have the same dimensions as a credit card, and (slightly less convenient but have more storage) 8 cm CD-Rs. But these are harder to obtain and generally more expensive than the standard 12 cm version. The small CDs also require a tray-loading drive; they can cause damage if inserted into a slot-loading drive. There also is no standard file system for rewritable optical media. Packet-writing utilities like DirectCD and InCD exist but produce discs that are not universally readable, despite their claiming to be based on the UDF standard. The upcoming Mount Rainier standard addresses this shortcoming in CD-RW media, but it still is not supported by most DVD and CD recorders or major operating systems. As a result, CDs/DVDs are a good way to record a great deal of information cheaply and also has the advantage of being able to put it into any console/optical disk player for playback, but not good for making ongoing small changes to a large collection of information; flash drives' ability to do this is their major advantage. A CD-R (Compact Disc-Recordable) is a thin (1. ... DirectCD is packet writing software, originally from Adaptec and now supported by Roxio. ... InCD is packet writing software by Nero AG for Microsoft Windows. ... The Universal Disk Format (UDF) is a format specification of a file system for storing files on optical media. ... The Mount Rainier logo Mount Rainier is a format for re-writable optical discs which provides for packet writing and defect management. ...

Security

Some flash drives feature encryption of the data stored on them, generally using full disk encryption below the file system. This prevents an unauthorized person from accessing the data stored on it. The disadvantage is that the drive is accessible only in the minority of computers which have compatible encryption software, for which no portable standard is widely deployed. It has been suggested that OTFE be merged into this article or section. ...

Some encryption applications allow running without installation. The executable files can be stored on the USB drive, together with the encrypted file image. The encrypted partition can be accessed on any computer running Microsoft Windows. Other flash drives allow the user to configure secure and public partitions of different sizes. Executable files for Windows, Macintosh, and Linux may be on the drive, depending on manufacturer support. Some security software may require administrative rights on the host PC to access data. A USB drive Portable software is a class of software that is suitable for use on portable drives such as a USB (thumb) drive or iPod or Palm PDA with drive mode, although any external hard drive could theoretically be used. ... “Windows” redirects here. ...

Newer flash drives support biometric fingerprinting to confirm the user's identity. As of mid-2005, this was a relatively costly alternative to standard password protection offered on many new USB flash storage devices. Most fingerprint scanning drives rely upon the host operating system to validate the fingerprint via a software driver, restricting the drive to Microsoft Windows computers. At Disney World, biometric measurements are taken of the fingers of multi-day pass users to ensure that the pass is used by the same person from day to day. ... This article is about human fingerprints. ... 2005 is a common year starting on Saturday of the Gregorian calendar. ... “Windows” redirects here. ...

Some manufacturers deploy physical authentication tokens in the form of a flash drive. These are used to control access to a sensitive system by containing encryption keys or, more commonly, communicating with security software on the target machine. The system is designed so the target machine will not operate except when the flash drive device is plugged into it. Some of these "PC lock" devices also function as normal flash drives when plugged into other machines. Chained parallel port copy prevention dongles. ...

All such forms of data protection security involve an increased risk of loss of access to the data by the legitimate owner/user.

Flash drives present a significant security challenge for large organizations. Their small size and ease of use allows unsupervised visitors or unscrupulous employees to smuggle confidential data out with little chance of detection. Equally, corporate and public computers alike are vulnerable to attackers connecting a flash drive to a free USB port and using malicious software such as rootkits or packet sniffers. To prevent this, some organizations forbid the use of flash drives, and some computers are configured to disable the mounting of USB mass storage devices by ordinary users, a feature introduced in Windows XP Service Pack 2; others use third-party software to control USB usage. In a lower-tech security solution, some organizations disconnect USB ports inside the computer or fill the USB sockets with epoxy. A rootkit is a general description of a set of programs which work to subvert control of an operating system from its legitimate operators. ... A packet sniffer (also known as a network analyzer or protocol analyzer or, for particular types of networks, an Ethernet sniffer or wireless sniffer) is computer software or computer hardware that can intercept and log traffic passing over a digital network or part of a network. ... Windows XP is a line of operating systems developed by Microsoft for use on general-purpose computer systems, including home and business desktops, notebook computers, and media centers. ... In chemistry, epoxy or polyepoxide is a thermosetting epoxide polymer that cures (polymerizes and crosslinks) when mixed with a catalyzing agent or hardener. Most common epoxy resins are produced from a reaction between epichlorohydrin and bisphenol-A. The first commercial attempts to prepare resins from epichlorohydrin occurred in 1927 in...

Naming

Recently, "USB flash drive" or simply "UFD" has emerged as the de facto standard term for these devices. However, the myriad different brand names and terminology used, in the past and currently, makes UFDs more difficult for manufacturers to market and for consumers to research. Some commonly used names are actually trademarks of particular companies. Some examples of this are Cruzer, TravelDrive, & Disgo. Manufacturing is the transformation of raw materials into finished goods for sale, or intermediate processes involving the production or finishing of semi-manufactures. ... For the magazine, see Marketing (magazine). ... In economics, consumers are individuals or households that consume goods and services generated within the economy. ...

Future developments

Semiconductor corporations have worked to reduce the cost of the components in a flash drive by integrating various flash drive functions in a single chip, thereby reducing the part-count and overall package cost.

Flash drive capacities on the market are continuously increasing. As of 2006, 64 MB and smaller capacity flash memory has been largely discontinued,^{[citation needed]} and 128 MB capacity flash memory is being phased out^{[citation needed]}. High-speed USB is now a standard for modern flash drives and capacities of up to 16GB are common^{[citation needed]}.

Lexar is attempting to introduce a USB FlashCard ^{[13] [14]}, which would be a compact USB flash drive intended to replace various kinds of flash memory cards. Pretec introduced a similar card, which also plugs into every USB port, but is just one quarter the thickness of the Lexar model ^[15] Lexar is an American manufacturer of various digital media and software based in Fremont, CA. Media manufactured by them include SD cards, Memory Sticks, keydrives, and CompactFlash cards. ... USB FlashCard is a new flash memory card format developed by Lexar, and announced on December 13, 2004[1]. There is a plethora of existing memory card formats such as SD, xD, and CompactFlash; the major advantage of USB FlashCard is that the cards are in fact standard USB flash...

SanDisk has introduced a new technology to allow controlled storage and usage of copyrighted materials on flash drives, primarily for use by students. This technology is termed FlashCP. SanDisk Corporation (NASDAQ: SNDK), formerly SunDisk, is an American multinational corporation which designs and markets flash memory card products. ... FlashCP FlashCP is a technology obtained by SanDisk in 2005 when they purcahsed the Israeli-based MDRM. FlashCP was originally developed under the trademarked name BootLocker. ...

See also

Electronics Portal

• External hard drive
• File synchronization
• List of backup software
• List of portable software
• LiveDistro - Computer Operating System on a Flash Drive
• Live USB
• Pocket hard drive
• Sneakernet
• USB Flash Drive Alliance
• USB Mass Storage Device
• Disk encryption software
• U3
• Portable application
• PHILM
• Flash drive

Image File history File links Nuvola_apps_ksim. ... A 3. ... File synchronization (or syncing) in computing is the process of making sure that two or more locations contain the same up-to-date files. ... This is a list of backup software, software which performs data backups, and providers of managed backup services. ... A USB drive Portable software is a class of software that is suitable for use on portable drives such as a USB (thumb) drive or iPod or Palm PDA with drive mode, although any external hard drive could theoretically be used. ... Gnoppix 0. ... A live USB is a USB flash drive containing a full operating system which can be booted from. ... The pocket hard drive is a higher capacity variant of the flash drive. ... In a non-network environment, the floppy disk was once the primary means of transferring data between computers. ... The USB Flash Drive Alliance, founded in December 2003 by Samsung, Lexar Media, Kingston Technology and others, is promoting the use of USB flash drives (also called keydrives). ... USB Mass Storage Devices are devices that use generic USB standards to grant access to a filesystem stored therin, usually in FAT32 format. ... To protect confidentiality of the data stored on a computer disk a computer security technique called disk encryption is used. ... U3 LLC is a joint venture that is backed by Sandisk and its subsidiary, M-Systems. ... A USB drive, shown with a 24 mm US quarter coin for scale. ... PHILM is a new media designed and marketed by T’emogique, Inc. ... A flash drive, related to a solid state drive, is a storage device that uses flash memory rather than conventional spinning platters to store data. ...

References

Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 141st day of the year (142nd in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 213th day of the year (214th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 125th day of the year (126th in leap years) in the Gregorian calendar. ... “PDF” redirects here. ... A kibibyte (a contraction of kilo binary byte) is a unit of information or computer storage, commonly abbreviated KiB (never kiB). 1 kibibyte = 210 bytes = 1,024 bytes The kibibyte is closely related to the kilobyte, which can be used either as a synonym for kibibyte or to refer to... “PDF” redirects here. ... A kibibyte (a contraction of kilo binary byte) is a unit of information or computer storage, commonly abbreviated KiB (never kiB). 1 kibibyte = 210 bytes = 1,024 bytes The kibibyte is closely related to the kilobyte, which can be used either as a synonym for kibibyte or to refer to... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 213th day of the year (214th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 7th day of the year in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 204th day of the year (205th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 213th day of the year (214th in leap years) in the Gregorian calendar. ...

External links

Wikimedia Commons has media related to:

USB flash drive

• Singapore firm wins patent on thumb drive
• USB for DOS
• The USB Flash Drive Alliance

Image File history File links Commons-logo. ...