A
trackball is a
pointing deviceA pointing device is an input interface that allows a user to input spatial data to a computer...
consisting of a
ballA ball is a round, usually spherical but sometimes ovoid, object with various uses. It is used in ball games, where the play of the game follows the state of the ball as it is hit, kicked or thrown by players. Balls can also be used for simpler activities, such as catch, marbles and juggling...
held by a socket containing sensors to detect a rotation of the ball about two axes—like an upside-down mouse with an exposed protruding ball. The user rolls the ball with the
thumbThe thumb is the first digit of the hand. When a person is standing in the medical anatomical position , the thumb is the lateral-most digit...
,
fingerA finger is a limb of the human body and a type of digit, an organ of manipulation and sensation found in the hands of humans and other primates....
s, or the palm of the
handA hand is a prehensile, multi-fingered extremity located at the end of an arm or forelimb of primates such as humans, chimpanzees, monkeys, and lemurs...
to move a
cursorIn computing, a cursor is an indicator used to show the position on a computer monitor or other display device that will respond to input from a text input or pointing device. The flashing text cursor may be referred to as a caret in some cases...
. Compared with a mouse, a trackball has no limits on effective travel; at times, a mouse can reach an edge of its working area while the operator still wishes to move the screen pointer farther. With a trackball, the operator just continues rolling. Some trackballs, such as Logitech's optical-pickoff types, have notably-low friction, as well as being dense (glass), so they can be spun to make them coast.
Large trackballs are common on
CADComputer-aided design , also known as computer-aided design and drafting , is the use of computer technology for the process of design and design-documentation. Computer Aided Drafting describes the process of drafting with a computer...
workstations for easy precision. Before the advent of the
touchpadA touchpad is a pointing device featuring a tactile sensor, a specialized surface that can translate the motion and position of a user's fingers to a relative position on screen. Touch pads are a common feature of laptop computers, and they are also used as a substitute for a mouse where desk...
, small trackballs were common on
portable computersA laptop, also called a notebook, is a personal computer for mobile use. A laptop integrates most of the typical components of a desktop computer, including a display, a keyboard, a pointing device and speakers into a single unit...
, where there may be no desk space on which to run a mouse. Some small thumbballs clip onto the side of the
keyboardIn computing, a keyboard is a typewriter-style keyboard, which uses an arrangement of buttons or keys, to act as mechanical levers or electronic switches...
and have integral buttons with the same function as mouse buttons. The trackball was invented by Tom Cranston and Fred Longstaff as part of the
Royal Canadian Navy'sThe history of the Royal Canadian Navy goes back to 1910, when the naval force was created as the Naval Service of Canada and renamed a year later by King George V. The Royal Canadian Navy is one of the three environmental commands of the Canadian Forces...
DATARDATAR, short for Digital Automated Tracking and Resolving, was a pioneering computerized battlefield information system.Development on DATAR was started by the Canadian Navy in partnership with Ferranti Canada in 1949. DATAR combined data from various ships providing commanders with an "overall...
system in 1952, eleven years before the mouse was invented. This first trackball used a Canadian
five-pin bowlingFive-pin bowling is a bowling variant which is played only in Canada, where most bowling alleys offer it, either alone or in combination with ten-pin bowling. It was devised around 1909 by Thomas F. Ryan in Toronto, Ontario, at his Toronto Bowling Club, in response to customers who complained that...
ball.
When mice still used a mechanical design (with slotted 'chopper' wheels interrupting a beam of light to measure rotation), trackballs had the advantage of being in contact with the user's hand, which is generally cleaner than the desk or mousepad and does not drag lint into the chopper wheels. The late 1990s replacement of mouseballs by direct optical tracking put trackballs at a disadvantage and forced them to retreat into niches where their distinctive merits remained more important. Most trackballs now have direct optical tracking which follows dots on the ball.
As with modern mice, most trackballs now have an auxiliary device primarily intended for scrolling. Some have a
scroll wheelA scroll wheel is a hard plastic or rubbery disc on a computer mouse that is perpendicular to the mouse surface. It is normally located between the left and right mouse buttons.- Functionality :...
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.
Three major companies
LogitechLogitech International S.A. is a global provider of personal peripherals for computers and other digital platforms headquartered in Romanel-sur-Morges, Switzerland. The company develops and markets products like peripheral devices for PCs, including keyboards, mice, microphones, game controllers...
, A4Tech, and Kensington currently produce trackballs, although A4Tech has not released a new model in several years.
MicrosoftMicrosoft Corporation is an American public multinational corporation headquartered in Redmond, Washington, USA that develops, manufactures, licenses, and supports a wide range of products and services predominantly related to computing through its various product divisions...
was a major producer, but has since discontinued all of its products. The Microsoft Trackball Explorer continues to be extremely popular (it has no analogous design in production by another company), with used models selling for ~$200 on
ebayeBay Inc. is an American internet consumer-to-consumer corporation that manages eBay.com, an online auction and shopping website in which people and businesses buy and sell a broad variety of goods and services worldwide...
.
Special applications
Large trackballs are sometimes seen on computerized special-purpose workstations, such as the radar consoles in an air-traffic control room or
sonarSonar is a technique that uses sound propagation to navigate, communicate with or detect other vessels...
equipment on a ship or submarine. Modern installations of such equipment may use mice instead, since most people now already know how to use one. However, military mobile anti-aircraft radars and submarine sonars tend to continue using trackballs, since they can be made more durable and more fit for fast emergency use. Large and well made ones allow easier high precision work, for which reason they may still be used in these applications (where they are often called "tracker balls") and in
computer-aided designComputer-aided design , also known as computer-aided design and drafting , is the use of computer technology for the process of design and design-documentation. Computer Aided Drafting describes the process of drafting with a computer...
.
Trackballs have appeared in computer and video games, particularly early
arcade gameAn arcade game is a coin-operated entertainment machine, usually installed in public businesses such as restaurants, bars, and amusement arcades. Most arcade games are video games, pinball machines, electro-mechanical games, redemption games, and merchandisers...
s (see a
List of trackball arcade games) notably Atari's
CentipedeCentipede is a vertically-oriented shoot 'em up arcade game produced by Atari, Inc. in 1980. The game was designed by Ed Logg along with Dona Bailey, one of the few female game programmers in the industry at this time. It was also the first arcade coin-operated game to have a significant female...
and
Missile CommandMissile Command is a 1980 arcade game by Atari, Inc. that was also licensed to Sega for European release. It is considered one of the most notable games from the Golden Age of Video Arcade Games...
– though Atari spells it "trak-ball".
Football, by
AtariAtari is a corporate and brand name owned by several entities since its inception in 1972. It is currently owned by Atari Interactive, a wholly owned subsidiary of the French publisher Atari, SA . The original Atari, Inc. was founded in 1972 by Nolan Bushnell and Ted Dabney. It was a pioneer in...
, released in 1978, is commonly misunderstood to be the first arcade game to use a trackball, but in
The Ultimate History of Video Games by Steven L. Kent the designer of
Football, Dave Stubben, claims they copied the design from a Japanese soccer game.
ConsoleA video game console is an interactive entertainment computer or customized computer system that produces a video display signal which can be used with a display device to display a video game...
trackballs, once common in the early 1980s, are now fairly uncommon: the
Atari 2600The Atari 2600 is a video game console released in October 1977 by Atari, Inc. It is credited with popularizing the use of microprocessor-based hardware and cartridges containing game code, instead of having non-microprocessor dedicated hardware with all games built in...
and
5200The Atari 5200 SuperSystem, commonly known as the Atari 5200, is a video game console that was introduced in 1982 by Atari Inc. as a higher end complementary console for the popular Atari 2600...
consoles had one as an optional
peripheralA peripheral is a device attached to a host computer, but not part of it, and is more or less dependent on the host. It expands the host's capabilities, but does not form part of the core computer architecture....
, with a
joystickA joystick is an input device consisting of a stick that pivots on a base and reports its angle or direction to the device it is controlling. Joysticks, also known as 'control columns', are the principal control in the cockpit of many civilian and military aircraft, either as a center stick or...
as standard. The
Apple PippinThe Pippin, known in Japan as , and marketed as Pipp!n, is a multimedia platform designed by Apple Computer and produced by Bandai in 1995...
, a console introduced in 1995 had a trackball built into its
gamepadA gamepad , is a type of game controller held in two hands, where the digits are used to provide input. Gamepads generally feature a set of action buttons handled with the right thumb and a direction controller handled with the left...
as standard. Trackballs are also preferred by many professional gamers, who value their consistency highly. A trackball requires no mousepad and enables the player to aim swiftly (in first person shooters). Trackballs remain in use in pub golf machines (such as
Golden TeeGolden Tee Golf is a golf arcade game series by Incredible Technologies.- About :There are many versions of the game that have been created throughout the years, but a fairly consistent feature between them all is the availability of a variety of 18-hole courses with different themes and levels of...
) to simulate swinging the club.
Computer gamers have been able to successfully use trackballs in most modern computer games, including FPS, RPG, and RTS genres, with any slight loss of speed compensated for with an increase in precision. Many trackball gamers are competent at "throwing" their cursor rapidly across the screen, by spinning the trackball, enabling (with practice) much faster motion than can be achieved with a
ball-less mouseAn optical computer mouse or "optic mouse" uses a light-emitting diode and photodiodes to detect movement relative to a surface, unlike a mechanical mouse which has a ball which rotates orthogonal shafts which drive chopper wheels for distance measurement.- Early optical mice :Early optical mice,...
and arm motion . However, many gamers are deterred by the time it takes to 'get used to' the different style of hand control that a trackball requires. Trackballs have also been regarded as excellent complements to analog joysticks, as pioneered by the
Assassin 3DThe Assassin 3D by First-Person Gaming is a trackball designed to be used simultaneously with a joystick to replace the keyboard and mouse combo for player movement and aiming in first-person shooter games like Quake and Unreal. James Barnes, president of First-Person Gaming, designed the original...
1996 trackball with joystick pass-through capability. This combination provides for two-hand aiming and a high accuracy and consistency replacement for the traditional mouse and keyboard combo generally used on
first-person shooterFirst-person shooter is a video game genre that centers the gameplay on gun and projectile weapon-based combat through first-person perspective; i.e., the player experiences the action through the eyes of a protagonist. Generally speaking, the first-person shooter shares common traits with other...
games. Many such games natively support joysticks and analog player movement, like Valve's
Half-Life and id Software's
Quake seriesThe Quake series is a line of first-person shooter video games produced by id Software.-Overview:The Quake series is somewhat unusual in that its focus changes frequently; the story of Quake II has nothing to do with Quake, and Quake III Arena has little to do with either of its predecessors...
.
Trackballs are provided as the pointing device in some
public internet access terminalsMany technologies and service plans for Internet access allow customers to connect to the Internet.Consumer use first became popular through dial-up connections in the 20th century....
. Unlike a mouse, a trackball can easily be built into a console, and cannot be ripped away or easily vandalised. Two examples are the Internet browsing consoles provided in some UK
McDonald'sMcDonald's Corporation is the world's largest chain of hamburger fast food restaurants, serving around 64 million customers daily in 119 countries. Headquartered in the United States, the company began in 1940 as a barbecue restaurant operated by the eponymous Richard and Maurice McDonald; in 1948...
outlets, and the BT Broadband Internet public phone boxes. This simplicity and ruggedness also makes them ideal for use in industrial computers.
Because trackballs for personal computers are stationary, they may require less space for operation than a
mouseIn computing, a mouse is a pointing device that functions by detecting two-dimensional motion relative to its supporting surface. Physically, a mouse consists of an object held under one of the user's hands, with one or more buttons...
, and may simplify use in confined or cluttered areas such as a small desk or a
rack-mountedA 19-inch rack is a standardized frame or enclosure for mounting multiple equipment modules. Each module has a front panel that is wide, including edges or ears that protrude on each side which allow the module to be fastened to the rack frame with screws.-Overview and history:Equipment designed...
terminal. They are generally preferred in laboratory setting for the same reason.
Ergonomics
People with a mobility impairment use trackballs as an
assistive technologyAssistive technology or adaptive technology is an umbrella term that includes assistive, adaptive, and rehabilitative devices for people with disabilities and also includes the process used in selecting, locating, and using them...
input device. Access to an alternative pointing device has become even more important for them with the dominance of graphically-oriented operating systems. There are many alternative systems to be considered. The control surface of a trackball is easier to manipulate and the buttons can be activated without affecting the pointer position.
Trackball users also often state that they are not limited to using the device on a flat desk surface. Trackballs can be used whilst browsing a laptop in bed, or wirelessly from an armchair to a PC playing a movie.
Trackballs are generally either thumb-operated, with a ball about an inch in diameter or smaller moved by one digit (almost always the thumb) and the buttons clicked by others, or finger-operated, with a ball over two inches in diameter operated by the middle fingers and the buttons by the thumb and little finger. Users favour one format or another for reasons of comfort, mobility, precision, or because it reduces strain on one part of the hand/wrist. Most, but not all, finger-operated designs are symmetrical in design, making them
usable by both handsAmbidexterity is the state of being equally adept in the use of both left and right appendages . It is one of the most famous varieties of cross-dominance. People that are naturally ambidextrous are rare, with only one out of one hundred people being naturally ambidextrous...
, while thumb-operated designs are by their nature asymmetric or “handed,” allowing the smallest examples to be held in the air. Thumb-operated trackballs are not generally available in left-handed configurations, due to small demand.
Some computer users prefer a trackball over the more common mouse for ergonomic reasons. There doesn't seem to be conclusive evidence of one being better than the other for most tasks. Users are encouraged to test different devices, and to maintain proper posture and scheduled breaks for comfort. Some disabled users find trackballs easier since they only have to move their thumb relative to their hand, instead of moving the whole hand, while others incur unacceptable fatigue of the thumb. Elderly people sometimes have difficulty holding a mouse still while
double-clickA double-click is the act of pressing a computer mouse button twice quickly without moving the mouse. Double-clicking allows two different actions to be associated with the same mouse button...
ing; the trackball allows them to let go of the cursor while using the button.
At times when a user is browsing menus or websites rather than typing, it is also possible to hold a trackball in the right hand like a television remote control, operating the ball with the right thumb and pressing the buttons with the left thumb, thus giving the fingers a rest.
Mobile phones
Some mobile phones have trackballs, including those in the
BlackBerryBlackBerry is a line of mobile email and smartphone devices developed and designed by Canadian company Research In Motion since 1999.BlackBerry devices are smartphones, designed to function as personal digital assistants, portable media players, internet browsers, gaming devices, and much more...
range, the T-Mobile Sidekick 3, and most HTC smartphones. These miniature trackballs are made to fit within the thickness of a mobile device, and are controlled by the tip of a finger or thumb.
On Mouses
In lieu of a
scroll wheelA scroll wheel is a hard plastic or rubbery disc on a computer mouse that is perpendicular to the mouse surface. It is normally located between the left and right mouse buttons.- Functionality :...
, some mouses include a tiny trackball sometimes called a
scroll ballA scroll wheel is a hard plastic or rubbery disc on a computer mouse that is perpendicular to the mouse surface. It is normally located between the left and right mouse buttons.- Functionality :...
. A popular example is Apple's
Mighty MouseThe Apple Mouse is a multi-button USB mouse manufactured and sold by Apple Inc. It was announced and sold for the first time on August 2, 2005, and a Bluetooth version was available from 2006 to 2009...
.