| flash disk consists of a NAND-type flash memory | | | | of the (at the time) commonly used floppy disks. |
| data storage device integrated with a USB (universal | | | | In 2000 Lexar introduced a Compact Flash (CF) card |
| serial bus) interface. USB flash drives are typically | | | | with a USB connection, and a companion card read |
| removable and rewritable, much smaller than a floppy | | | | writer and USB cable that eliminated the need for a |
| disk (1 to 4 inches or 2.5 to 10 cm), and most USB | | | | USB hub. |
| flash drives weigh less than an ounce [1]. Storage | | | | In 2004 Trek Technology brought several lawsuits |
| capacities typically range from 64 MB to 64 GB[2] | | | | against other USB flash drive manufacturers and |
| with steady improvements in size and price per | | | | distributors in an attempt to assert its patent rights |
| gigabyte. Some allow 1 million write or erase | | | | to the USB flash drive. A court in Singapore ordered |
| cycles[3][4] and have 10-year data retention,[5] | | | | competitors to cease selling similar products[8] that |
| connected by USB 1.1 or USB 2.0. | | | | would be covered by Trek's patent, but a court in |
| USB flash drives offer potential advantages over | | | | the United Kingdom revoked[9] one of Trek's |
| other portable storage devices, particularly the floppy | | | | patents in that country. |
| disk. They have a more compact shape, operate | | | | [edit]Second generation |
| faster, hold much more data, have a more durable | | | | Modern flash drives have USB 2.0 connectivity. |
| design, and operate more reliably due to their lack of | | | | However, they do not currently use the full 480 Mbit |
| moving parts. Additionally, it has become increasingly | | | | s (60MB/s) the USB 2.0 Hi-Speed specification |
| common for computers to be sold without floppy | | | | supports due to technical limitations inherent in NAND |
| disk drives. USB ports, on the other hand, appear on | | | | flash. The fastest drives currently available use a dual |
| almost every current mainstream PC and laptop. | | | | channel controller, although they still fall considerably |
| These types of drives use the USB mass storage | | | | short of the transfer rate possible from a current |
| standard, supported natively by modern operating | | | | generation hard disk, or the maximum high speed |
| systems such as Windows, Mac OS X, Linux, and | | | | USB throughput. |
| other Unix-like systems. USB drives with USB 2.0 | | | | Typical overall file transfer speeds vary considerably, |
| support can also operate faster than an optical disc | | | | and should be checked before purchase; speeds may |
| drive, while storing a larger amount of data in a much | | | | be given in megabytes or megabits per second. |
| smaller space. | | | | Typical fast drives claim to read at up to 30 |
| Nothing actually moves in a flash drive: the term drive | | | | megabytes/s (MB/s) and write at about half that. |
| persists because computers read and write | | | | Older "USB full speed" 12 megabit/s devices are |
| flash-drive data using the same system commands as | | | | limited to a maximum of about 1 MB/s. |
| for a mechanical disk drive, with the storage | | | | Size and style of packaging |
| appearing to the computer operating system and | | | | Flash drives come in various, sometimes bulky or |
| user interface as just another drive.[4] | | | | novelty, shapes and sizes, in this case ikura sushi |
| A flash drive consists of a small printed circuit board | | | | Some manufacturers differentiate their products by |
| protected inside a plastic, metal, or rubberised case, | | | | using elaborate housings, which are often bulky and |
| robust enough for carrying with no additional | | | | make the drive difficult to connect to the USB port. |
| protection—in a pocket or on a key chain, for | | | | Because the USB port connectors on a computer |
| example. The USB connector is protected by a | | | | housing are often closely spaced, plugging a flash |
| removable cap or by retracting into the body of the | | | | drive into a USB port may block an adjacent port. |
| drive, although it is not liable to be damaged if | | | | Such devices may only carry the USB logo if sold |
| exposed. Most flash drives use a standard type-A | | | | with a separate extension cable. |
| USB connection allowing plugging into a port on a | | | | USB flash drives have been integrated into other |
| personal computer. | | | | commonly-carried items such as watches, pens, and |
| First commercial product | | | | even the Swiss Army Knife; others have been fitted |
| Flash drive with retractable USB connector | | | | with novelty cases such as toy cars or LEGO bricks. |
| Trek Technology and IBM began selling the first USB | | | | The small size, robustness and cheapness of USB |
| flash drives commercially in 2000. Singaporean | | | | flash drives make them an increasingly popular |
| company Trek Technology sold a model dubbed the | | | | peripheral for case modding. |
| "ThumbDrive," and IBM marketed the first such | | | | Heavy or bulky flash drive packaging can make for |
| drives in North America, with its product the | | | | unreliable operation when plugged directly into a USB |
| "DiskOnKey" (which was manufactured by the Israeli | | | | port; this can be relieved by a USB extension cable. |
| company M-Systems). IBM's USB flash drive became | | | | Such cables are USB-compatible, but do not conform |
| available December 15, 2000[6][7], and had a storage | | | | to the USB 1.0 standard. |
| capacity of 8 MB, more than five times the capacity | | | | |