Editing USB flash drive (section)

==History==
The basis for USB flash drives is [[flash memory]], a type of [[floating-gate]] [[semiconductor memory]] invented by [[Fujio Masuoka]] in the early 1980s. Flash memory uses [[floating-gate MOSFET]] transistors as [[memory cell (computing)|memory cells]].<ref>{{cite web |title=Flash Memory |url=http://www.iue.tuwien.ac.at/phd/windbacher/node14.html |website=[[TU Wien]] |access-date=4 December 2019 |archive-date=29 November 2019 |archive-url=https://web.archive.org/web/20191129233409/http://www.iue.tuwien.ac.at/phd/windbacher/node14.html |url-status=live }}</ref><ref>{{cite book |last1=Harris |first1=David |last2=Harris |first2=Sarah |title=Digital Design and Computer Architecture |date=2010 |publisher=[[Morgan Kaufmann]] |isbn=978-0-08-054706-0 |pages=263–4 |url=https://books.google.com/books?id=5X7JV5-n0FIC&pg=PA263 |language=en}}</ref>

Multiple individuals have staked a claim to having invented the USB flash drive. On April 5, 1999, [[Junior (chess program)|Amir Ban]], [[Dov Moran]], and [[Oron Ogdan]] of [[M-Systems]], an [[Israel]]i company, filed a patent application entitled "Architecture for a Universal Serial Bus-Based PC Flash Disk".<ref>{{Cite patent|title=Architecture for a universal serial bus-based PC flash disk|gdate=1999-04-05|url=https://patents.google.com/patent/US6148354A/en}} {{Webarchive|url=https://web.archive.org/web/20210729220703/https://patents.google.com/patent/US6148354A/en |date=2021-07-29 }}</ref><ref name=":0" /> The patent was subsequently granted on November 14, 2000, and these individuals have often been recognized as the inventors of the USB flash drive.<ref>{{Cite web|title=Who invented the Thumb-Drive?|url=https://kodakdigitizing.com/blogs/news/who-invented-the-thumb-drive|access-date=2021-03-25|website=Kodak Digitizing|archive-date=2020-12-05|archive-url=https://web.archive.org/web/20201205085457/https://kodakdigitizing.com/blogs/news/who-invented-the-thumb-drive|url-status=live}}</ref> Also in 1999, [[Shimon Shmueli]], an engineer at IBM, submitted an invention disclosure asserting that he had invented the USB flash drive.<ref name=":0" /><ref>{{Cite web|date=2015-04-23|title=History Of The Flash Drive|url=https://mediafast.com/history-of-the-flash-drive/|access-date=2021-03-25|website=MediaFast|language=en-US|archive-date=2021-03-02|archive-url=https://web.archive.org/web/20210302115516/https://mediafast.com/history-of-the-flash-drive/|url-status=live}}</ref> A Singaporean company named [[Trek 2000 International]] is the first company known to have sold a USB flash drive, and has also maintained that it is the original inventor of the device.<ref>{{Cite web|title=Who Invented the USB Flash Drive? - Premium USB|url=https://www.premiumusb.com/blog/who-invented-the-usb-flash-drive|access-date=2021-03-25|website=www.premiumusb.com|archive-date=2021-02-12|archive-url=https://web.archive.org/web/20210212025358/https://www.premiumusb.com/blog/who-invented-the-usb-flash-drive|url-status=live}}</ref> Finally [[Pua Khein-Seng]], a Malaysian engineer, has also been recognized by some as a possible inventor of the device.<ref>{{Cite web|title='Father of pen drive' now a Datuk {{!}} The Star|url=https://www.thestar.com.my/news/nation/2012/07/17/father-of-pen-drive-now-a-datuk|access-date=2021-03-25|website=www.thestar.com.my|date=17 July 2012 |archive-date=2021-11-11|archive-url=https://web.archive.org/web/20211111052701/https://www.thestar.com.my/news/nation/2012/07/17/father-of-pen-drive-now-a-datuk|url-status=live}}</ref>

Given these competing inventor claims, patent disputes involving the USB flash drive have arisen over the years. Both [[Trek 2000 International]] and [[Netac Technology]] have accused others of infringing their patents on the USB flash drive.<ref>{{Cite web|title=Patent Expires for Flash Memory Sticks, Invented by a Chinese Company-Jiemian Global|url=https://en.jiemian.com/article/3723200.html|access-date=2021-03-25|website=en.jiemian.com|archive-date=2021-05-09|archive-url=https://web.archive.org/web/20210509125418/https://en.jiemian.com/article/3723200.html|url-status=live}}</ref><ref>{{cite news| url=http://www.bangkokpost.com/breaking_news/breakingnews.php?id=70859| title=Singapore firm wins patent on thumb drive |newspaper=The Straits Times | access-date=2006-08-01}}</ref><ref>{{cite news | url=http://eresources.nlb.gov.sg/infopedia/articles/SIP_1071_2010-03-23.html | work=nlb.gov.sg | title=Trek 2000 and the ThumbDrive | date=March 23, 2010 | access-date=2016-06-25 | archive-date=2020-09-03 | archive-url=https://web.archive.org/web/20200903134043/https://eresources.nlb.gov.sg/infopedia/articles/SIP_1071_2010-03-23.html | url-status=live }}</ref> However, the question of who was the first to invent the USB flash drive has multiple claims persists. Netac Technology got the basic American copyright on December 7, 2004. And in the lawsuit, the PNY company paid 1,000 million dollars to Netac.

===Technology improvements===
Flash drives are often measured by the rate at which they transfer data. Transfer rates may be given in megabytes per second (MB/s), megabits per second (Mbit/s), or in optical drive multipliers such as "180X" (180 times 150&nbsp;[[Kibibyte|KiB]]/s).<ref>{{cite web|url=http://vampiric.us/index.php/articles/hardware/optical/opticalthroughpm|title=4 Optical Drives through Port Multiplier|website=vampiric.us|archive-url=https://web.archive.org/web/20141228185855/http://vampiric.us/index.php/articles/hardware/optical/opticalthroughpm|archive-date=28 December 2014|url-status=dead|access-date=22 December 2014|df=dmy-all}}</ref> File transfer rates vary considerably among devices. Second generation flash drives have claimed to read at up to 30&nbsp;MB/s and write at about half that rate, which was about 20 times faster than the theoretical transfer rate achievable by the previous model, USB&nbsp;1.1, which is limited to 12&nbsp;Mbit/s (1.5&nbsp;MB/s) with accounted overhead.<ref>{{cite web|url=http://www.diffen.com/difference/USB_1.0_vs_USB_2.0|title=USB 1.0 vs. USB 2.0|publisher=Diffen|access-date=22 December 2014|archive-date=21 December 2014|archive-url=https://web.archive.org/web/20141221111405/http://www.diffen.com/difference/USB_1.0_vs_USB_2.0|url-status=live}}</ref> The effective transfer rate of a device is significantly affected by the data access pattern.<ref>{{cite web|url=https://www.usenix.org/legacy/event/usenix09/tech/full_papers/vandebogart/vandebogart_html/index.html|title=Reducing Seek Overhead with Application-Directed Prefetching|website=Usenix.org|publisher=Usenix|access-date=22 December 2014|archive-date=25 January 2022|archive-url=https://web.archive.org/web/20220125214635/https://www.usenix.org/legacy/event/usenix09/tech/full_papers/vandebogart/vandebogart_html/index.html|url-status=live}}</ref>

By 2002, USB flash drives had [[USB 2.0]] connectivity, which has 480&nbsp;[[megabit|Mbit]]/s as the transfer rate upper bound; after accounting for the protocol overhead {{citation needed span|date=June 2022|text=that translates to a 35&nbsp;[[Megabyte|MB]]/s effective throughput.|reason=Previously used source not only gives a different value (40&nbsp;MB/s), but is itself linking Wikipedia as its source.}} That same year, Intel sparked widespread use of second generation USB by including them within its laptops.<ref name=":2">{{Cite news|url=https://www.cnet.com/news/want-a-laptop-with-usb-3-0-the-few-the-proud/|title=Want a laptop with USB 3.0? The few, the proud|date=2010-09-19|work=CNET|access-date=2018-10-10|language=en|archive-date=2018-10-10|archive-url=https://web.archive.org/web/20181010174343/https://www.cnet.com/news/want-a-laptop-with-usb-3-0-the-few-the-proud/|url-status=live}}</ref>

By 2010, the maximum available storage capacity for the devices had reached upwards of 128&nbsp;GB.<ref name=":1">{{cite news|url=http://www.time.com/time/specials/packages/article/0,28804,2023689_2023703_2023613,00.html|archive-url=https://web.archive.org/web/20101028085259/http://www.time.com/time/specials/packages/article/0,28804,2023689_2023703_2023613,00.html|url-status=dead|archive-date=October 28, 2010|title=All-Time 100 Gadgets|date=2010-10-25|magazine=Time}}</ref> [[USB 3.0]] was slow to appear in laptops. Through 2010, the majority of laptop models still contained only USB 2.0.<ref name=":2" />

In January 2013, tech company Kingston, released a flash drive with 1&nbsp;TB of storage.<ref>{{Cite news|url=https://www.usatoday.com/story/technologylive/2013/01/09/kingston-terabyte-flash-drive-ces/1820159/|title=Kingston unveils 1 terabyte flash drive|work=USA Today|access-date=2018-10-10|language=en|archive-date=2018-10-10|archive-url=https://web.archive.org/web/20181010174422/https://www.usatoday.com/story/technologylive/2013/01/09/kingston-terabyte-flash-drive-ces/1820159/|url-status=live}}</ref> The first [[USB 3.1]] [[USB-C|type-C]] flash drives, with read/write speeds of around 530&nbsp;MB/s, were announced in March 2015.<ref>{{cite web|url=http://www.gizmofusion.com/2015/03/pk-the-worlds-first-usb-kit-with-3-1-technology/|title=PK: the World's First USB Kit with 3.1 technology|access-date=1 June 2016|archive-date=31 May 2016|archive-url=https://web.archive.org/web/20160531121125/http://www.gizmofusion.com/2015/03/pk-the-worlds-first-usb-kit-with-3-1-technology/|url-status=live}}</ref> By July 2016, flash drives with 8 to 256&nbsp;GB capacity were sold more frequently than those with capacities between 512&nbsp;GB and 1&nbsp;TB.<ref name="digitaltrends.com" /><ref name="techradar1" /> In 2017, Kingston Technology announced the release of a 2-TB flash drive.<ref>{{Cite news|url=https://money.cnn.com/2017/01/05/technology/kingston-technology-biggest-flash-drive-two-terabytes/index.html|title=The world's biggest flash drive can store more than 160 HD movies|last=Mullen|first=Jethro|work=CNNMoney|access-date=2018-10-10|archive-date=2018-10-10|archive-url=https://web.archive.org/web/20181010215055/https://money.cnn.com/2017/01/05/technology/kingston-technology-biggest-flash-drive-two-terabytes/index.html|url-status=live}}</ref> In 2018, SanDisk announced a 1&nbsp;TB USB-C flash drive, the smallest of its kind.<ref>{{Cite web|url=https://www.theverge.com/circuitbreaker/2018/1/9/16867044/sandisk-prototype-1tb-usb-c-flash-drive-worlds-smallest-ces-2018|title=SanDisk shows off the world's smallest 1TB USB-C flash drive at CES|website=TheVerge.com|date=9 January 2018|access-date=18 December 2019|archive-date=18 December 2019|archive-url=https://web.archive.org/web/20191218061916/https://www.theverge.com/circuitbreaker/2018/1/9/16867044/sandisk-prototype-1tb-usb-c-flash-drive-worlds-smallest-ces-2018|url-status=live}}</ref>

{| border="1" cellpadding="4" cellspacing="0" style="float:right; background:#f9f9f9; border:1px #aaa solid; border-collapse:collapse; margin-left:1em;"
|-
| style="background:#e7e7e7; text-align:center;" colspan="2"|
[[File:Usbkey internals.jpg|350px]]<br />'''Internals of a typical USB flash drive'''
|-
!1
|USB Standard-A, "male" plug
|-
!2
|USB mass storage controller device
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!3
|Test point
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!4
|[[Flash memory|Flash memory chip]]
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!5
|[[Crystal oscillator]]
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!6
|[[LED]] (Optional)
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!7
|[[Write protection|Write-protect]] switch (Optional)
|-
!8
|Space for second flash memory chip
|}

On a USB flash drive, one end of the device is fitted with a single [[USB plugs|Standard-A USB plug]]; some flash drives additionally offer a [[micro USB]] or USB-C plug, facilitating data transfers between different devices.<ref>{{cite web |last=Broida |first=Rick |url=http://reviews.cnet.com/8301-19736_7-57615094-251/pkparis-unveils-worlds-smallest-android-flash-drive/ |title=PKparis unveils world's smallest Android flash drive &#124; Android Atlas - CNET Reviews |publisher=Reviews.cnet.com |date=2013-12-10 |access-date=2014-02-19 |archive-date=2014-02-19 |archive-url=https://web.archive.org/web/20140219215734/http://reviews.cnet.com/8301-19736_7-57615094-251/pkparis-unveils-worlds-smallest-android-flash-drive/ |url-status=live }}</ref>