Incomputing, amouseis apointing devicethat detectstwo-dimensionalmotion relative to a surface. This motion is typically translated into the motion of apointeron adisplay, which allows for fine control of agraphical user interface.Physically, a mouse consists of an object held in one's hand, with one or more buttons. Mice often also feature other elements, such as touch surfaces and "wheels", which enable additional control and dimensional input.

History[edit]Thetrackball, a related pointing device, was invented in 1941 byRalph Benjaminas part of aWorld War II-erafire-controlradarplotting system calledComprehensive Display System(CDS). Benjamin was then working for the BritishRoyal NavyScientific Service. Benjamin's project usedanalog computersto calculate the future position of target aircraft based on several initial input points provided by a user with ajoystick. Benjamin felt that a more elegant input device was needed and invented aball trackercalled "roller ball", for this purpose.[5][6]The device was patented in 1947,[6]but only a prototype using a metal ball rolling on two rubber-coated wheels was ever built, and the device was kept as a military secret.[5]Another early trackball was built by Britishelectrical engineerKenyon Taylorin collaboration with Tom Cranston and Fred Longstaff. Taylor was part of the originalFerranti Canada, working on theRoyal Canadian Navy'sDATAR(Digital Automated Tracking and Resolving) system in 1952.[7]DATAR was similar in concept to Benjamin's display. The trackball used four disks to pick up motion, two each for the X and Y directions. Several 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. Adigital computercalculated the tracks, and sent the resulting data to other ships in a task force usingpulse-code modulationradio signals. This trackball used a standard Canadianfive-pin bowlingball. It was not patented, as it was a secret military project as well.[8][9]

Early mouse patents. From left to right: Opposing track wheels by Engelbart, Nov. 1970,U.S. Patent 3,541,541. Ball and wheel byRider, Sept. 1974,U.S. Patent 3,835,464. Ball and two rollers with spring by Opocensky, Oct. 1976,U.S. Patent 3,987,685Independently,Douglas Engelbartat the Stanford Research Institute (nowSRI International) invented his first mouse prototype in the 1960s with the assistance of his lead engineerBill English.[10]They christened the device themouseas early models had a cord attached to the rear part of the device looking like a tail and generally resembling the commonmouse.[11]Engelbart never received any royalties for it, as his employer SRI held the patent, which ran out before it became widely used in personal computers.[12]The invention of the mouse was just a small part of Engelbart's much larger project, aimed at augmenting human intellect via theAugmentation Research Center.[13][14]

InventorDouglas Engelbartholding the first computer mouse,[15]showing the wheels that make contact with the working surface.Several other experimental pointing-devices developed for Engelbart's oN-Line System (NLS) exploited different body movements for example, head-mounted devices attached to the chin or nose but ultimately the mouse won out because of its speed and convenience.[16]The first mouse, a bulky device (pictured) used two wheels perpendicular to each other: the rotation of each wheel translated into motion along oneaxis. At the time of the "Mother of All Demos", Englebart's group had been using their second generation, 3-button mouse for about a year. See the image of that mouse atPicture showing 2nd G mouse(A public domain version of this image would be nice.)On 2 October 1968, just a few months before Engelbart releasedhis demoon 9 December 1968, a mouse device namedRollkugel(German for "rolling ball") was released that had been developed and published by the German companyTelefunken. As the name suggests and unlike Engelbart's mouse, the Telefunken model already had a ball. It was based on an earlier trackball-like device (also namedRollkugel) that was embedded into radar flight control desks. This had been developed around 1965 by a team led by Rainer Mallebrein at TelefunkenKonstanzfor the GermanBundesanstalt fr Flugsicherungas part of their TR86 process computer system with its SIG100-86[17]vector graphics terminal.

The first ball-based computer mouse in 1968,TelefunkenRollkugelRKS 100-86for theirTR 86process computer system.When the development for the Telefunken main frameTR 440(de)began in 1965,Mallebreinand his team came up with the idea of "reversing" the existingRollkugelinto a moveable mouse-like device, so that customers did not have to be bothered with mounting holes for the earlier trackball device. Together with light pens and trackballs, it was offered as optional input device for their system since 1968. Some samples, installed at theLeibniz-Rechenzentrumin Munich in 1972, are still well preserved.[18][19]Telefunken considered the invention too small to apply for a patent on their device.TheXerox Altowas one of the first computers designed for individual use in 1973, and is regarded as the grandfather of computers that utilize the mouse.[20]Inspired byPARC's Alto, theLilith, a computer which had been developed by a team aroundNiklaus WirthatETH Zrichbetween 1978 and 1980, provided a mouse as well. The third marketed version of an integrated mouse shipped as a part of a computer and intended for personal computer navigation came with theXerox 8010 Star Information Systemin 1981.By 1982 the Xerox 8010 was probably the best-known computer with a mouse, and the forthcomingApple Lisawas rumored to use one, but the peripheral remained obscure; Jack Hawley of The Mouse House reported that one buyer for a large organization believed at first that his company soldlab mice. Hawley, who manufactured mice for Xerox, stated that "Practically, I have the market all to myself right now"; a Hawley mouse cost $415.[21]That yearMicrosoftmade the decision to make theMS-DOSprogramMicrosoft Wordmouse-compatible, and developed the first PC-compatible mouse. Microsoft's mouse shipped in 1983, thus beginningMicrosoft Hardware.[22]However, the mouse remained relatively obscure until the 1984 appearance of theMacintosh 128K, which included an updated version of theLisa Mouse[23]and theAtari STin 1985.Operation[edit]Further information:Point and clickA mouse typically controls the motion of apointerin two dimensions in a graphical user interface (GUI). The mouse turns movements of the hand backward and forward, left and right into equivalent electronic signals that in turn are used to move the pointer.The relative movements of the mouse on the surface are applied to the position of the pointer on the screen, which signals the point where actions of the user take place, so that the hand movements are replicated by the pointer.[24]Clicking or hovering (stopping movement while the cursor is within the bounds of an area) can select files, programs or actions from a list of names, or (in graphical interfaces) through small images called "icons" and other elements. For example, a text file might be represented by a picture of a paper notebook, and clicking while the cursor hovers this icon might cause a text editing program to open the file in a window.Different ways of operating the mouse cause specific things to happen in the GUI:[24] Click: pressing and releasing a button. (left)Single-click: clicking the main button. (left)Double-click: clicking the button two times in quick succession counts as a different gesture than two separate single clicks. (left)Triple-click: clicking the button three times in quick succession. Right-click: clicking the secondary button. Middle-click: clicking the tertiary button. Drag and drop: pressing and holding a button, then moving the mouse without releasing. (Using the command "drag with the right mouse button" instead of just "drag" when one instructs a user to drag an object while holding the right mouse button down instead of the more commonly used left mouse button.) Mouse button chording(a.k.a. Rocker navigation). Combination of right-click then left-click. Combination of left-click then right-click or keyboard letter. Combination of left or right-click and the mouse wheel. Clicking while holding down amodifier key. Moving the pointer a long distance: When a practical limit of mouse movement is reached, one lifts up the mouse, brings it to the opposite edge of the working area while it is held above the surface, and then replaces it down onto the working surface. This is often not necessary, because acceleration software detects fast movement, and moves the pointer significantly faster in proportion than for slow mouse motion. Multi-touch: this method is similar to a multi-touch trackpad on a laptop with support for tap input for multiple fingers, the most famous example being theApple Magic Mouse.Mouse gestures[edit]Main article:Pointing device gestureUsers can also employ micegesturally; meaning that a stylized motion of the mouse cursor itself, called a "gesture", can issue a command or map to a specific action. For example, in a drawing program, moving the mouse in a rapid "x" motion over a shape might delete the shape.Gestural interfaces occur more rarely than plain pointing-and-clicking; and people often find them more difficult to use, because they require finer motor-control from the user. However, a few gestural conventions have become widespread, including thedrag and dropgesture, in which:1. The user presses the mouse button while the mouse cursor hovers over an interface object2. The user moves the cursor to a different location while holding the button down3. The user releases the mouse buttonFor example, a user might drag-and-drop a picture representing a file onto a picture of atrash can, thus instructing the system to delete the file.Standard semantic gestures include: Crossing-based goal Drag and drop Menutraversal Pointing Rollover(Mouseover) SelectionSpecific uses[edit]Other uses of the mouse's input occur commonly in special application-domains. In interactivethree-dimensional graphics, the mouse's motion often translates directly into changes in the virtual objects' or camera's orientation. For example, in the first-person shooter genre of games (see below), players usually employ the mouse to control the direction in which the virtual player's "head" faces: moving the mouse up will cause the player to look up, revealing the view above the player's head. A related function makes an image of an object rotate, so that all sides can be examined. 3D design and animation software often modally chords many different combinations to allow objects and cameras to be rotated and moved through space with the few axes of movement mice can detect.When mice have more than one button, software may assign different functions to each button. Often, the primary (leftmost in aright-handedconfiguration) button on the mouse will select items, and the secondary (rightmost in a right-handed) button will bring up a menu of alternative actions applicable to that item. For example, on platforms with more than one button, theMozillaweb browser will follow a link in response to a primary button click, will bring up a contextual menu of alternative actions for that link in response to a secondary-button click, and will often open the link in a newtaborwindowin response to a click with the tertiary (middle) mouse button.Variants[edit]Mechanical mice[edit]Operating an opto-mechanical mouse.1. moving the mouse turns the ball.2. X and Y rollers grip the ball and transfer movement3. Opticalencodingdisks include light holes.4. InfraredLEDsshine through the disks.5. Sensors gather light pulses to convert to X and Y vectors.

The German companyTelefunkenpublished on their early ball mouse on October 2, 1968.[18]Telefunken's mouse was sold as optional equipment for their computer systems.Bill English, builder of Engelbart's original mouse,[25]created a ball mouse in 1972 while working forXerox PARC.[26]The ball mouse replaced the external wheels with a single ball that could rotate in any direction. It came as part of the hardware package of theXerox Altocomputer. Perpendicularchopper wheelshoused inside the mouse's body chopped beams of light on the way to light sensors, thus detecting in their turn the motion of the ball. This variant of the mouse resembled an invertedtrackballand became the predominant form used withpersonal computersthroughout the 1980s and 1990s. The Xerox PARC group also settled on the modern technique of using both hands to type on a full-size keyboard and grabbing the mouse when required.

Mechanical mouse, shown with the top cover removed. The scroll wheel is grey, to the right of the ball.The ball mouse has two freely rotating rollers. They are located 90 degrees apart. One roller detects the forwardbackward motion of the mouse and other the leftright motion. Opposite the two rollers is a third one (white, in the photo, at 45 degrees) that is spring-loaded to push the ball against the other two rollers. Each roller is on the same shaft as anencoderwheel that has slotted edges; the slots interrupt infrared light beams to generate electrical pulses that represent wheel movement. Each wheel's disc, however, has a pair of light beams, located so that a given beam becomes interrupted, or again starts to pass light freely, when the other beam of the pair is about halfway between changes.Simple logic circuits interpret the relative timing to indicate which direction the wheel is rotating. Thisincremental rotary encoderscheme is sometimes called quadrature encoding of the wheel rotation, as the two optical sensor produce signals that are in approximatelyquadrature phase. The mouse sends these signals to the computer system via the mouse cable, directly as logic signals in very old mice such as the Xerox mice, and via a data-formatting IC in modern mice. The driver software in the system converts the signals into motion of the mouse cursor along X and Y axes on the computer screen.

Hawley Mark II Mice from the Mouse HouseThe ball is mostly steel, with a precision spherical rubber surface. The weight of the ball, given an appropriate working surface under the mouse, provides a reliable grip so the mouse's movement is transmitted accurately. Ball mice and wheel mice were manufactured for Xerox by Jack Hawley, doing business as The Mouse House in Berkeley, California, starting in 1975.[27][28]Based on another invention by Jack Hawley, proprietor of the Mouse House,Honeywellproduced another type of mechanical mouse.[29][30]Instead of a ball, it had two wheels rotating at off axes.Key Troniclater produced a similar product.[31]Modern computer mice took form at thecole Polytechnique Fdrale de Lausanne(EPFL) under the inspiration of ProfessorJean-Daniel Nicoudand at the hands ofengineerandwatchmakerAndr Guignard.[32]This new design incorporated a single hard rubber mouseball and three buttons, and remained a common design until the mainstream adoption of the scroll-wheel mouse during the 1990s.[33]In 1985,Ren Sommeradded amicroprocessorto Nicoud's and Guignard's design.[34]Through this innovation, Sommer is credited with inventing a significant component of the mouse, which made it more "intelligent;"[34]though optical mice from Mouse Systems had incorporated microprocessors by 1984.[35]Another type of mechanical mouse, the "analog mouse" (now generally regarded as obsolete), usespotentiometersrather than encoder wheels, and is typically designed to beplug compatiblewith an analog joystick. The "Color Mouse", originally marketed byRadioShackfor theirColor Computer(but also usable onMS-DOSmachines equipped with analog joystick ports, provided the software accepted joystick input) was the best-known example.Optical and laser mice[edit]

A wireless optical mouse

A standard wireless mouse and its connectorMain article:Optical mouseOptical mice rely entirely on one or morelight-emitting diodes(LEDs) and an imaging array ofphotodiodesto detect movement relative to the underlying surface, eschewing the internal moving parts a mechanical mouse uses in addition to its optics. A laser mouse is an optical mouse that uses coherent (laser) light.The earliest optical mice detected movement on pre-printed mousepad surfaces, whereas the modern LED optical mouse works on most opaque diffuse surfaces; it is usually unable to detect movement on specular surfaces like polished stone. Laser diodes are also used for better resolution and precision, improving performance on opaque specular surfaces. Battery powered, wireless optical mice flash the LED intermittently to save power, and only glow steadily when movement is detected.Inertial and gyroscopic mice[edit]Often called "air mice" since they do not require a surface to operate, inertial mice use a tuning fork or otheraccelerometer(US Patent 4787051, published in 1988) to detect rotary movement for every axis supported. The most common models (manufactured by Logitech and Gyration) work using 2 degrees of rotational freedom and are insensitive to spatial translation. The user requires only small wrist rotations to move the cursor, reducing user fatigue or "gorilla arm".Usually cordless, they often have a switch to deactivate the movement circuitry between use, allowing the user freedom of movement without affecting the cursor position. A patent for an inertial mouse claims that such mice consume less power than optically based mice, and offer increased sensitivity, reduced weight and increasedease-of-use.[36]In combination with a wireless keyboard an inertial mouse can offer alternative ergonomic arrangements which do not require a flat work surface, potentially alleviating some types of repetitive motion injuries related to workstation posture.3D mice[edit]Also known as bats,[37]flying mice, or wands,[38]these devices generally function throughultrasoundand provide at least threedegrees of freedom. Probably the best known example would be3Dconnexion/Logitech's SpaceMouse from the early 1990s. In the late 1990s Kantek introduced the 3D RingMouse. This wireless mouse was worn on a ring around a finger, which enabled the thumb to access three buttons. The mouse was tracked in three dimensions by a base station.[39]Despite a certain appeal, it was finally discontinued because it did not provide sufficient resolution.A recent consumer 3D pointing device is theWii Remote. While primarily a motion-sensing device (that is, it can determine its orientation and direction of movement), Wii Remote can also detect its spatial position by comparing the distance and position of the lights from theIRemitter using its integrated IR camera (since thenunchukaccessory lacks a camera, it can only tell its current heading and orientation). The obvious drawback to this approach is that it can only produce spatial coordinates while its camera can see the sensor bar.A mouse-related controller called the SpaceBall[40]has a ball placed above the work surface that can easily be gripped. With spring-loaded centering, it sends both translational as well as angular displacements on all six axes, in both directions for each. In November 2010 a German Company called Axsotic introduced a new concept of 3D mouse called 3D Spheric Mouse. This new concept of a true six degree-of-freedom input device uses a ball to rotate in 3 axes without any limitations.[41] Logitech spacemouse 3D. On display at the Bolo computer Museum,EPFL, Lausanne. Silicon Graphics SpaceBall model 1003 (1988), allowing manipulation of objects with 6 degrees of freedom. On display at the Muse Bolo, EPFL.Tactile mice[edit]In 2000,Logitechintroduced a "tactile mouse" that contained a smallactuatorto make the mouse vibrate. Such a mouse can augment user-interfaces withhapticfeedback, such as giving feedback when crossing awindowboundary. To surf by touch requires the user to be able to feel depth or hardness; this ability was realized with the first electrorheological tactile mice[42]but never marketed.Pucks[edit]Tablet digitizersare sometimes used with accessories called pucks, devices which rely on absolute positioning, but can be configured for sufficiently mouse-like relative tracking that they are sometimes marketed as mice.[43]Ergonomic mice[edit]

A vertical mouse.As the name suggests, this type of mouse is intended to provide optimum comfort and avoid injuries such ascarpal tunnel syndrome,arthritisand otherrepetitive strain injuries. It is designed to fit natural hand position and movements, to reduce discomfort.When holding a typical mouse,ulnaandradiusbones on thearmare crossed. Some designs attempt to place the palm more vertically, so the bones take more natural parallel position.[44]Some limit wrist movement, encouraging to use arm instead that may be less precise but more optimal from the health point of view. A mouse may be angled from the thumb downward to the opposite side this is known to reduce wrist pronation.[45]However such optimizations make the mouse right or left hand specific, making more problematic to change the tired hand.Time magazinehas criticised manufacturers for offering few or no left-handed ergonomic mice: "Oftentimes I felt like I was dealing with someone whod never actually met a left-handed person before."[46]

Keyboard with roller bar mouseAnother solution is a pointing bar device. The so-calledroller bar mouseis positioned snuggly in front of the keyboard, thus allowing bi-manual accessibility.[47]Gaming mice[edit]These mice are specifically designed for use incomputer games. They typically employ a wide array of controls and buttons[48]and have designs that differ radically from traditional mice.[48]It is also common for gaming mice, especially those designed for use inreal-time strategygames such asStarCraft, or inmultiplayer online battle arenagames such asDota 2to have a relatively high sensitivity, measured in dots per inch (DPI).[49]Some advanced mice from gaming manufacturers also allow users to customize the weight of the mouse by adding or subtracting weights to allow for easier control.[50]Ergonomic quality is also an important factor in gaming mice, as extended gameplay times may render further use of the mouse to be uncomfortable.[51]Some mice have been designed to have adjustable features such as removable and/or elongated palm rests, horizontally adjustable thumb rests and pinky rests. Some mice may include several different rests with their products to ensure comfort for a wider range of target consumers.[52]Gaming mice are held bygamersin three styles ofgrip:[53][54]1. Palm Grip: the hand rests on the mouse, with extended fingers.[55]2. Claw Grip: palm rests on the mouse, bent fingers.[56]3. Finger-Tip Grip: bent fingers, palm doesn't touch the mouse.[57]Connectivity and communication protocols[edit]

A Microsoft wireless Arc mouse, marketed as "travel friendly" and foldable but otherwise operated exactly like other 3-button wheel-based optical miceTo transmit their input, typical cabled mice use a thin electrical cord terminating in a standard connector, such asRS-232C,PS/2,ADBorUSB. Cordless mice instead transmit data viainfraredradiation (seeIrDA) orradio(includingBluetooth), although many such cordless interfaces are themselves connected through the aforementioned wired serial buses.While the electrical interface and the format of the data transmitted by commonly available mice is currently standardized on USB, in the past it varied between different manufacturers. Abus mouseused a dedicated interface card for connection to anIBM PCor compatible computer.Mouse use in DOS applications became more common after the introduction of the Microsoft mouse, largely because Microsoft provided an open standard for communication between applications and mouse driver software. Thus, any application written to use the Microsoft standard could use a mouse with a driver that implements the same API, even if the mouse hardware itself was incompatible with Microsoft's. This driver provides the state of the buttons and the distance the mouse has moved in units that its documentation calls "mickeys",[58]as does theAllegro library.[59]Serial interface and protocol[edit]Standard PC mice once used theRS-232C serial port via aD-subminiatureconnector, which provided power to run the mouse's circuits as well as data on mouse movements. The Mouse Systems Corporation version used a five-byte protocol and supported three buttons. The Microsoft version used a three-byte protocol and supported two buttons. Due to the incompatibility between the two protocols, some manufacturers sold serial mice with a mode switch: "PC" for MSC mode, "MS" for Microsoft mode.[60]PS/2 interface and protocol[edit]For more details on this topic, seePS/2 connector.With the arrival of theIBM PS/2personal-computer series in 1987, IBM introduced theeponymousPS/2 interface for mice and keyboards, which other manufacturers rapidly adopted. The most visible change was the use of a round 6-pinmini-DIN, in lieu of the former 5-pin connector. In default mode (calledstream mode) a PS/2 mouse communicates motion, and the state of each button, by means of 3-byte packets.[61]For any motion, button press or button release event, a PS/2 mouse sends, over a bi-directional serial port, a sequence of three bytes, with the following format:Bit 7Bit 6Bit 5Bit 4Bit 3Bit 2Bit 1Bit 0

Byte 1YVXVYSXS1MBRBLB

Byte 2X movement

Byte 3Y movement

Here, XS and YS represent the sign bits of the movement vectors, XV and YV indicate an overflow in the respective vector component, and LB, MB and RB indicate the status of the left, middle and rightmouse buttons(1 = pressed). PS/2 mice also understand several commands for reset and self-test, switching between different operating modes, and changing the resolution of the reported motion vectors.AMicrosoft IntelliMouserelies on an extension of the PS/2 protocol: the ImPS/2 or IMPS/2 protocol (the abbreviation combines the concepts of "IntelliMouse" and "PS/2"). It initially operates in standard PS/2 format, for backwards compatibility. After the host sends a special command sequence, it switches to an extended format in which a fourth byte carries information about wheel movements. The IntelliMouse Explorer works analogously, with the difference that its 4-byte packets also allow for two additional buttons (for a total of five).[62]Mouse vendors also use other extended formats, often without providing public documentation. The Typhoon mouse uses 6-byte packets which can appear as a sequence of two standard 3-byte packets, such that an ordinary PS/2drivercan handle them.[63]For 3-D (or 6-degree-of-freedom) input, vendors have made many extensions both to the hardware and to software. In the late 1990s Logitech created ultrasound based tracking which gave 3D input to a few millimetres accuracy, which worked well as an input device but failed as a profitable product. In 2008, Motion4U introduced its "OptiBurst" system using IR tracking for use as a Maya (graphics software) plugin.Apple Desktop Bus[edit]

Apple Macintosh Plusmice: beige mouse (left), platinum mouse (right), 1986In 1986Applefirst implemented theApple Desktop Busallowing the daisy-chaining together of up to 16 devices, including arbitrarily many mice and other devices on the same bus with no configuration whatsoever. Featuring only a single data pin, the bus used a purely polled approach to computer/mouse communications and survived as the standard on mainstream models (including a number of non-Apple workstations) until 1998 wheniMacjoined the industry-wide switch to usingUSB. Beginning with the Bronze Keyboard PowerBook G3 in May 1999, Apple dropped the external ADB port in favor of USB, but retained an internal ADB connection in thePowerBook G4for communication with its built-in keyboard and trackpad until early 2005.USB[edit]The industry-standardUSB(Universal Serial Bus) protocol and its connector have become widely used for mice; it is among the most popular types.[64]