Editing Trackball (section)

== History ==
{{Anchor|Ball tracker|Roller ball|Rollkugel}}

The trackball was invented as part of a post-[[World War II]]-era radar plotting system named [[Comprehensive Display System]] (CDS) by [[Ralph Benjamin]] when working for the British [[Royal Navy]] Scientific Service.<ref name="Hill_2005_Benjamin"/><ref name="Copping_2013_Benjamin"/> Benjamin's project used [[analog computer]]s to calculate the future position of target aircraft based on several initial input points provided by a user with a [[joystick]]. Benjamin felt that a more elegant input device was needed and invented a ''ball tracker''<ref name="Hill_2005_Benjamin"/><ref name="Copping_2013_Benjamin"/> system called the ''roller ball''<ref name="Hill_2005_Benjamin"/> for this purpose in 1946.<ref name="Hill_2005_Benjamin"/><ref name="Copping_2013_Benjamin"/> The device was patented in 1947,<ref name="Hill_2005_Benjamin">{{cite web
|title=RALPH BENJAMIN: An Interview Conducted by Peter C. J. Hill
|first=Peter C. J.
|last=Hill
|date=2005-09-16
|type=Interview
|series=Interview #465
|url=http://www.ieeeghn.org/wiki/index.php/Oral-History:Ralph_Benjamin
|access-date=2013-07-18
|archive-date=2013-10-15
|archive-url=https://web.archive.org/web/20131015084700/http://www.ieeeghn.org/wiki/index.php/Oral-History:Ralph_Benjamin
|url-status=live
}}</ref> but only a prototype using a metal ball rolling on two rubber-coated wheels was ever built<ref name="Copping_2013_Benjamin"/> and the device was kept as a military secret.<ref name="Copping_2013_Benjamin">{{cite web
|title=Briton: 'I invented the computer mouse 20 years before the Americans'
|first=Jasper
|last=Copping
|publisher=[[Telegraph Media Group|The Telegraph]]
|date=2013-07-11
|url=https://www.telegraph.co.uk/technology/news/10174366/Briton-I-invented-the-computer-mouse-20-years-before-the-Americans.html
|access-date=2013-07-18
|archive-date=2013-07-14
|archive-url=https://web.archive.org/web/20130714164020/http://www.telegraph.co.uk/technology/news/10174366/Briton-I-invented-the-computer-mouse-20-years-before-the-Americans.html
|url-status=live
}}</ref> Production versions of the CDS used joysticks.

The CDS system had also been viewed by a number of engineers from [[Ferranti-Packard|Ferranti Canada]], who returned to Canada and began development of the [[Royal Canadian Navy]]'s [[DATAR]] system in 1952. Principal designers Tom Cranston, Fred Longstaff and [[Kenyon Taylor]] chose the trackball as the primary input, using a standard [[five-pin bowling]] ball as the roller. DATAR was similar in concept to Benjamin's display, but used a [[digital computer]] to calculate tracks, and sent the resulting data to other ships in a task force using [[pulse-code modulation]] radio signals.<ref name="Vardalas_1994_DATAR">{{Cite web
|title=From DATAR To The FP-6000 Computer: Technological Change In A Canadian Industrial Context
|first=John
|last=Vardalas
|publisher=IEEE
|work=IEEE Annals of the History of Computing
|date=1994
|volume=16
|series=No. 2
|url=https://ewh.ieee.org/reg/7/millennium/fp6000/fp6000_datar.html
|access-date=2007-10-15
|archive-date=2008-09-07
|archive-url=https://web.archive.org/web/20080907233232/http://ewh.ieee.org/reg/7/millennium/fp6000/fp6000_datar.html
|url-status=live
}}</ref>

DATAR's trackball used four disks to pick up motion, two each for the X and Y directions. Several additional rollers provided mechanical support. When the ball was rolled, the pickup discs spun and contacts on their outer rim made periodic contact with wires, producing pulses of output with each movement of the ball. By counting the pulses, the physical movement of the ball could be determined.

Since 1966, the American company ''Orbit Instrument Corporation'' produced a device named ''X-Y Ball Tracker'', a trackball, which was embedded into radar flight control desks.<ref name="Bülow_2009_Rollkugel"/><ref>{{cite web|title=ORBIT X-Y Ball Tracker|publisher=oldmouse.com|url=http://www.oldmouse.com/trackball/orbit.shtml|access-date=2013-08-03|archive-date=2013-10-05|archive-url=https://web.archive.org/web/20131005122238/http://www.oldmouse.com/trackball/orbit.shtml|url-status=usurped}}</ref>

A similar trackball device at the German ''{{lang|de|{{Interlanguage link multi|Bundesanstalt für Flugsicherung|de}}}}'' was constructed by a team around {{ill|Rainer Mallebrein|de}} of Telefunken {{lang|de|Konstanz}} as part of the development for the [[Telefunken]] computer infrastructure around the main frame {{Interlanguage link multi|Telefunken TR 440|de|3=TR 440|lt=TR 440}}, process computer [[Telefunken TR 86|TR&nbsp;86]] and video terminal [[Telefunken SIG 100|SIG&nbsp;100-86]],<ref>{{cite web
|title=SIG-100 video terminal and mouse
|url=http://www.computerhistory.org/revolution/input-output/14/346/1874
|access-date=2013-08-03
|archive-date=2013-08-27
|archive-url=https://web.archive.org/web/20130827055238/http://www.computerhistory.org/revolution/input-output/14/346/1874
|url-status=live
}}</ref> which began in 1965.<ref name="Bülow_2009_Rollkugel"/> This trackball was called ''{{lang|de|Rollkugel}}'' (German for "rolling ball"). Somewhat later, the idea of "reversing" this device led to the introduction of the first computer [[ball mouse]] (still named ''{{lang|de|[[Rollkugel (mouse device)|Rollkugel]]}}'', model [[RKS 100-86]]), which was offered as an alternative input device to light pens and trackballs for Telefunken's computer systems since 1968.<ref name="Bülow_2009_Rollkugel">{{cite web |url=http://www.heise.de/newsticker/Auf-den-Spuren-der-deutschen-Computermaus--/meldung/136901 |title=Auf den Spuren der deutschen Computermaus |trans-title=In the footsteps of the German computer mouse |language=de |publisher=Heise Verlag |date=2009-04-28 |access-date=2013-01-07 |archive-date=2013-11-27 |archive-url=https://web.archive.org/web/20131127230503/http://www.heise.de/newsticker/meldung/Auf-den-Spuren-der-deutschen-Computermaus-216255.html |url-status=live }}</ref><ref name="OldMouse_Telefunken">{{cite web|url=http://www.oldmouse.com/mouse/misc/telefunken.shtml|title=Telefunken's 'Rollkugel'|publisher=oldmouse.com|access-date=2013-08-03|archive-date=2013-08-08|archive-url=https://web.archive.org/web/20130808075232/http://www.oldmouse.com/mouse/misc/telefunken.shtml|url-status=usurped}}</ref><ref name="Ebner_2018">{{cite news |title=Entwickler aus Singen über die Anfänge der Computermaus: "Wir waren der Zeit voraus" |language=de |trans-title=Singen-based developer about the advent of the computer mouse: "We were ahead of time" |author-first=Susanne |author-last=Ebner |department=Leben und Wissen |date=2018-01-24 |newspaper=[[Südkurier]] |publisher=[[Südkurier GmbH]] |publication-place=Konstanz, Germany |url=https://www.suedkurier.de/ueberregional/wissenschaft/Entwickler-aus-Singen-ueber-die-Anfaenge-der-Computermaus-Wir-waren-der-Zeit-voraus;art1350069,9590558 |access-date=2021-08-22 |url-status=live |archive-url=https://web.archive.org/web/20210302234231/https://www.suedkurier.de/ueberregional/wissenschaft/Entwickler-aus-Singen-ueber-die-Anfaenge-der-Computermaus-Wir-waren-der-Zeit-voraus;art1350069,9590558 |archive-date=2021-03-02}}</ref>

In later trackball models the electrical contacts were replaced by an [[optical chopper]] wheel, which had small slots cut into it in rather than electrical contacts. With an LED for illumination from one side and an optical sensor on the other, rotation of the wheel periodically blocks and unblocks the light, so the sensor produces electrical pulses to indicate that rotation is occurring.

Mice used the same basic system for determining motion, but had the problem that the ball was in contact with the desk or [[mousepad]]. In order to provide smooth motion the balls were often covered with an anti-slip surface treatment, which was, by design, sticky. Rolling the mouse tended to pick up any dirt and drag it into the system where it would clog the chopper wheels, demanding cleanup. In contrast the trackball is in contact only with the user's hand, which tends to be cleaner. In the late 1990s both mice and trackballs began using direct optical tracking which follows dots on the ball, avoiding the need for anti-slip surface treatment.

As with modern mice, most trackballs now have an auxiliary device primarily intended for scrolling. Some have a [[scroll wheel]] like most mice, but the most common type is a “scroll ring” which is spun around the ball. Kensington's SlimBlade Trackball similarly tracks the ball itself in three dimensions for scrolling.

{{asof|1989}} and into the 2020s, two major companies developed and produce consumer trackballs, [[Logitech]] and [[ACCO Brands|Kensington]], although Logitech has narrowed its product line to two models. Other smaller companies occasionally offer a trackball in their product line. [[Microsoft]] produced popular models including The Microsoft Trackball Explorer, but has since discontinued all of its products.

In September 2017 Logitech announced release of MX-Ergo Mouse,<ref name="techscoop.in">{{Cite web|url=https://www.techscoop.in/2017/09/gaming-mouse-that-goes-across-multiple.html|title=Gaming Mouse that goes across multiple systems: Logitech's MX-Ergo Trackball Mouse|access-date=2017-09-14|archive-date=2017-09-14|archive-url=https://web.archive.org/web/20170914220758/https://www.techscoop.in/2017/09/gaming-mouse-that-goes-across-multiple.html|url-status=live}}</ref> which was released after 6 years of its last trackball mouse.