USB Flash Drive - Wikipedia, the Free Encyclopedia
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USB flash drive - Wikipedia, the free encyclopedia http://en.wikipedia.org/wiki/USB_flash_drive USB flash drive From Wikipedia, the free encyclopedia A USB flash drive is a data storage device that includes flash memory with an integrated Universal Serial Bus (USB) interface. USB flash drives are typically removable and rewritable, and physically much smaller than a floppy disk. Most weigh less than 30 grams (1.1 oz). [1] As of September 2011, drives of up to 256 gigabytes (GB) are available. [2] A one-terabyte (TB) drive was unveiled at the 2013 Consumer Electronics Show and will be available during 2013. [3] Storage capacities as large as 2 TB are planned, with steady SanDisk Cruzer Micro, a brand of [4] improvements in size and price per capacity expected. Some allow USB flash drives up to 100,000 write/erase cycles, depending on the exact type of memory chip used, and a 10-year shelf storage time.[5][6][7] USB flash drives are often used for the same purposes for which floppy disks or CD-ROMs were used, i.e., for storage, back-up and transfer of computer files. They are smaller, faster, have thousands of times more capacity, and are more durable and reliable because they have no moving parts. Until about 2005, most desktop and laptop computers were supplied with floppy disk drives in addition to USB A Kingston card reader which accepts ports, but floppy disk drives have been abandoned due to their age Micro SD memory cards (Transcend and due to USB flash drives' growing popularity. card shown inserted) and acts as a USB USB flash drives use the USB mass storage standard, supported flash drive, resulting in a size of natively by modern operating systems such as Linux, Mac OS X, approximately 2 cm in length, 1 cm in Windows, and other Unix-like systems, as well as many BIOS boot width and 2 mm in thickness ROMs. USB drives with USB 2.0 support can store more data and transfer faster than much larger optical disc drives like CD-RW or DVD-RW drives and can be read by many other systems such as the Xbox 360, PlayStation 3, DVD players and in a number of handheld devices such as smartphones and tablet computers. A flash drive has no moving parts to be driven; therefore, it's not a true drive. The term drive persists because computers read and write flash drive data using the same system commands as for a mechanical disk drive, with the storage appearing to the computer operating system and user interface as just another drive. A flash drive consists of a small printed circuit board carrying the circuit elements and a USB connector, insulated electrically and protected inside a plastic, metal, or rubberized case which can be carried in a pocket or on a key chain, for example. The USB connector may be protected by a removable cap or by retracting into the body of the drive, although it is not likely to be damaged if unprotected. Most flash drives use a standard type-A USB connection allowing connection with a port on a personal computer, but drives for other interfaces also exist. USB flash drives draw power from the computer via the USB connection. Some devices combine the functionality of a digital audio player with USB flash storage; they require a battery only when used to play music. Leader providers are Gartner and Kingston Technology. Contents 1 History 1 de 17 08/04/2013 11:38 p.m. USB flash drive - Wikipedia, the free encyclopedia http://en.wikipedia.org/wiki/USB_flash_drive 1.1 Creator controversy 1.2 First commercial product 1.3 Second generation 1.4 Third generation 2 Design and implementation 3 Technology 3.1 Essential components 3.2 Additional components 3.3 Size and style of packaging 3.4 File system 3.5 Longevity 4 Fake products 5 File transfer speeds 6 Uses 6.1 Personal data transport 6.2 Secure storage of data, application and software files 6.3 Application carriers 6.4 Computer forensics and law enforcement 6.5 Booting operating systems 6.6 Windows Vista, Windows 7 and Windows 8 ReadyBoost 6.7 Audio players 6.8 Media storage and marketing 6.9 Arcades 6.10 Brand and product promotion 6.11 Backup 6.12 Operating system installation media 6.13 Security systems 7 Advantages and disadvantages 7.1 Disadvantages 8 Comparison with other portable storage 8.1 Tape 8.2 Floppy disk 8.3 Optical media 8.4 Flash memory cards 8.5 External hard disk 8.6 Obsolete devices 8.7 Encryption and Security 9 Security threats 10 Naming 11 Current and future developments 12 See also 13 References 14 External links History Creator controversy USB flash drives were invented by Amir Ban, Dov Moran and Oron Ogdan, all of the Israeli company M-Systems, who filed US patent 6,148,354 in April 1999; [8] however, the patent describes a product that has a cable between the memory unit and the USB connector. IBM Patent Disclosure RPS8-1999-0201 from September 13, 1999 by Shimon Shmueli accurately describes the USB flash drive. [citation needed ] IBM 2 de 17 08/04/2013 11:38 p.m. USB flash drive - Wikipedia, the free encyclopedia http://en.wikipedia.org/wiki/USB_flash_drive partnered with M-Systems to bring the product to market. Shmueli was later an expert witness for M-Systems and as part of his testimony in the Singapore court presented the IBM disclosure and evidence to the fact that he invented the USB flash drive. M-Systems' product, developed by a team led by Dan Harkabi, and named the DiskOnKey, was announced in September 2000. [9] Competing claims have been made by a Singaporean company Trek Technology and a Chinese company Netac Technology,[10] but based on patents that post-date M-Systems'. Both Trek Technology and Netac Technology have tried to protect their patent claims. Trek won a Singaporean suit, [11] but a court in the United Kingdom revoked one of Trek's UK patents. [12] While Netac Technology has brought lawsuits against PNY Technologies,[13] Lenovo,[14] aigo,[15] Sony,[16][17][18] and Taiwan's Acer and Tai Guen Enterprise Co, [18] most companies that manufacture USB flash drives do so without regard for Trek and Netac's patents. Pua Khein-Seng from Malaysia claims to have incorporated the world's first single chip USB flash controller. He is currently the CEO of Phison Electronics Corp, which is based in Taiwan. [19] First commercial product Trek Technology and IBM began selling the first USB flash drives commercially in 2000. Trek Technology sold a model under the brand name "ThumbDrive", and IBM marketed the first such drives in North America with its product named the "DiskOnKey," which was developed and manufactured by M-Systems.[20] IBM's USB flash drive became available on December 15, 2000, [21] and had a storage capacity of 8 MB, more than five times the capacity of the then-common floppy disks. In 2000, Lexar introduced a Compact Flash (CF) card with a USB connection, and a companion card read/writer and USB cable that eliminated the need for a USB hub. [citation needed ] Second generation Modern flash drives have USB 2.0 connectivity. However, they do not currently use the full 480 Mbit/s (60 MB/s) which the USB 2.0 Hi-Speed specification supports because of technical limitations inherent in NAND flash. The fastest drives currently available use a dual channel controller, alt hough they still fall considerably short of the transfer rate possible from a current generation hard disk, or the maximum high speed USB throughput. File transfer speeds vary considerably. Speeds may be given in Mbyte per second, Mbit per second or optical drive multipliers such as "180X" (180 times 150 KiB per second). Typical fast drives claim to read at up to 30 megabytes/s (MB/s) and write at about half that speed. This is about 20 times faster than USB 1.1 "full speed" devices, which are limited to a maximum speed of 12 Mbit/s (1.5 MB/s). Third generation Like USB 2.0 before it, USB 3.0 offers dramatically improved data transfer rates compared to its predecessor. USB 3.0 was announced in late 2008, but consumer devices were not available until the beginning of 2010. The USB 3.0 interface specifies transfer rates up to 5 Gbit/s (625 MB/s), compared to USB 2.0's 480 Mbit/s (60 MB/s). All USB 3.0 devices are backward compatible with USB 2.0 ports. Computers with USB 3.0 ports are becoming very popular and common. Many newer laptops and desktops have at least one such port. USB 3.0 port expansion cards are available to upgrade older systems, and many newer motherboards feature two or more USB 3.0 jacks. Even though the USB 3.0 interface allows extremely high data transfer speeds, as of 2011 most USB 3.0 flash drives do not utilize the full speed of the USB 3.0 interface due to limitations of their memory controllers (though some four channel memory controllers are now coming to market). Design and implementation 3 de 17 08/04/2013 11:38 p.m. USB flash drive - Wikipedia, the free encyclopedia http://en.wikipedia.org/wiki/USB_flash_drive On a USB flash drive, one end is fitted with a single Standard-A USB plug. Inside the plastic casing is a small printed circuit board, which has some power circuitry and a small number of surface-mounted integrated circuits (ICs).