Computer mouse

A computer mouse with the most common standard features: two buttons and a scroll wheel, which can also act as a third button.

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. It sometimes features other elements, such as "wheels", which allow the user to perform various system-dependent operations, or extra buttons or features that can add more control or dimensional input. The mouse's motion typically translates into the motion of a pointer on a display, which allows for fine control of a graphical user interface.

Naming

The first known publication of the term mouse as a pointing device is in Bill English's 1965 publication "Computer-Aided Display Control".

The online Oxford Dictionaries entry for mouse states the plural for the small rodent is mice, while the plural for the small computer connected device is either mice or mouses. However, in the usage section of the entry it states that the more common plural is mice, and that the first recorded use of the term in the plural is mice as well (though it cites a 1984 use of mice when there were actually several earlier ones).

The term mice was seen in print in "The Computer as a Communication Device", written by J. C. R. Licklider in 1968.

The fourth edition of The American Heritage Dictionary of the English Language endorses both computer mice and computer mouses as correct plural forms for computer mouse. Some authors of technical documents may prefer either mouse devices or the more generic pointing devices. The plural mouses treats mouse as a "headless noun".

Early mice

Early mouse patents. From left to right: Opposing track wheels by Engelbart, Nov. 1970, U.S. patent 3,541,541. Ball and wheel by Rider, Sept. 1974, U.S. patent 3,835,464. Ball and two rollers with spring by Opocensky, Oct. 1976, U.S. patent 3,987,685

The trackball, a related pointing device, was invented by Tom Cranston, Fred Longstaff and Kenyon Taylor working on the Royal Canadian Navy's DATAR project in 1952. It used a standard Canadian five-pin bowling ball. It was not patented, as it was a secret military project.

Independently, Douglas Engelbart at the Stanford Research Institute invented the first mouse prototype in 1963, with the assistance of his colleague Bill English. They christened the device the mouse as early models had a cord attached to the rear part of the device looking like a tail and generally resembling the common mouse. Engelbart never received any royalties for it, as his patent ran out before it became widely used in personal computers.

The invention of the mouse was just a small part of Engelbart's much larger project, aimed at augmenting human intellect.

The first computer mouse, held by inventor Douglas Engelbart, 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 simplicity and convenience. The first mouse, a bulky device (pictured) used two wheels perpendicular to each other: the rotation of each wheel translated into motion along one axis. Engelbart received patent US3,541,541 on November 17, 1970 for an "X-Y Position Indicator for a Display System". At the time, Engelbart envisaged that users would hold the mouse continuously in one hand and type on a five-key chord keyset with the other. The concept was preceded in the 19th century by the telautograph, which also anticipated the fax machine.

A Smaky mouse, as invented at the EPFL by Jean-Daniel Nicoud and André Guignard

Just a few weeks before Engelbart released his demo in 1968, a mouse had already been developed and published by the German company Telefunken. Unlike Engelbart's mouse, the Telefunken model had a ball, as it can be seen in most later models until today. Since 1970, it was shipped as part and sold together with Telefunken Computers. Some models from the year 1972 are still well preserved.

The second marketed integrated mouse shipped as a part of a computer and intended for personal computer navigation came with the Xerox 8010 Star Information System in 1981. However, the mouse remained relatively obscure until the 1984 appearance of the Apple Macintosh, which included an updated version of the original Lisa Mouse. In 1984 PC columnist John C. Dvorak dismissively commented on the newly-released computer with a mouse: "There is no evidence that people want to use these things".

Variants

Mechanical mice

Operating an opto-mechanical mouse. moving the mouse turns the ball. X and Y rollers grip the ball and transfer movement Optical encoding disks include light holes. Infrared LEDs shine through the disks. Sensors gather light pulses to convert to X and Y vectors.

German company Telefunken published on their early ball mouse, called "Rollkugel" (German for "rolling ball"), on 2 October 1968. Telefunken's mouse was then sold commercially as optional equipment for their TR-440 computer, which was first marketed in 1968. Telefunken did not apply for a patent on their device.

Bill English, builder of Engelbart's original mouse, created a ball mouse in 1972 while working for Xerox PARC.

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 the Xerox Alto computer. Perpendicular chopper wheels housed 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 inverted trackball and became the predominant form used with personal computers throughout 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 forward–backward motion of the mouse and other the left–right 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 an encoder wheel 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. This scheme is sometimes called quadrature encoding of the wheel rotation, as the two optical sensor produce signals that are in approximately quadrature 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.

The 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.

Hawley Mark II Mice from the Mouse House

Ball mice and wheel mice were manufactured for Xerox by Jack Hawley, doing business as The Mouse House in Berkeley, California, starting in 1975.

Based on another invention by Jack Hawley, proprietor of the Mouse House, Honeywell produced another type of mechanical mouse. Instead of a ball, it had two wheels rotating at off axes. Keytronic later produced a similar product.

Modern computer mice took form at the École polytechnique fédérale de Lausanne (EPFL) under the inspiration of Professor Jean-Daniel Nicoud and at the hands of engineer and watchmaker André Guignard. 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. In 1985, René Sommer added a microprocessor to Nicoud's and Guignard's design. Through this innovation, Sommer is credited with inventing a significant component of the mouse, which made it more "intelligent;" though optical mice from Mouse Systems had incorporated microprocessors by 1984.

Another type of mechanical mouse, the "analog mouse" (now generally regarded as obsolete), uses potentiometers rather than encoder wheels, and is typically designed to be plug compatible with an analog joystick. The "Color Mouse", originally marketed by Radio Shack for their Color Computer (but also usable on MS-DOS machines equipped with analog joystick ports, provided the software accepted joystick input) was the best-known example.

Optical and laser mice

A wireless optical mouse on a mousepad

Main article: Optical mouse

Optical mice make use of one or more light-emitting diodes (LEDs) and an imaging array of photodiodes to detect movement relative to the underlying surface, rather than internal moving parts as does a mechanical mouse. A laser mouse is an optical mouse that uses coherent (laser) light.

Inertial and gyroscopic mice

Often called "air mice" since they do not require a surface to operate, inertial mice use a tuning fork or other accelerometer (US Patent 4787051) 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 increased ease-of-use. 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

Also known as bats, flying mice, or wands, these devices generally function through ultrasound and provide at least three degrees of freedom. Probably the best known example would be 3DConnexion/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. Despite a certain appeal, it was finally discontinued because it did not provide sufficient resolution.

A recent consumer 3D pointing device is the Wii 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 the IR emitter using its integrated IR camera (since the nunchuk accessory 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 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.

Tactile mice

In 2000, Logitech introduced the "tactile mouse", which contained a small actuator that made the mouse vibrate. Such a mouse can augment user-interfaces with haptic feedback, such as giving feedback when crossing a window boundary. 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 but never marketed.

Connectivity and communication protocols

A Microsoft wireless Arc mouse

To transmit their input, typical cabled mice use a thin electrical cord terminating in a standard connector, such as RS-232C, PS/2, ADB or USB. Cordless mice instead transmit data via infrared radiation (see IrDA) or radio (including Bluetooth), 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. A bus mouse used a dedicated interface card for connection to an IBM PC or 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 Microsoft compatible driver (even if the mouse hardware itself was incompatible with Microsoft's). An interesting footnote is that the Microsoft driver standard communicates mouse movements in standard units called "mickeys", as does the Allegro library.

Serial interface and protocol

Standard PC mice once used the RS-232C serial port via a D-subminiature connector, 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.

PS/2 interface and protocol

Further information: PS/2 connector

With the arrival of the IBM PS/2 personal-computer series in 1987, IBM introduced the eponymous PS/2 interface for mice and keyboards, which other manufacturers rapidly adopted. The most visible change was the use of a round 6-pin mini-DIN, in lieu of the former 5-pin connector. In default mode (called stream mode) a PS/2 mouse communicates motion, and the state of each button, by means of 3-byte packets. 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 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
Byte 1	YV	XV	YS	XS	1	MB	RB	LB
Byte 2	X movement
Byte 3	Y 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 right mouse 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.

A Microsoft IntelliMouse relies 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).

The Typhoon mouse uses 6-byte packets which can appear as a sequence of two standard 3-byte packets, such that an ordinary PS/2 driver can handle them.

Mouse vendors also use other extended formats, often without providing public documentation.

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

Apple Macintosh Plus mice (left) Beige mouse (right) Platinum mouse 1986

In 1986 Apple first implemented the Apple Desktop Bus allowing 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 when iMac joined the industry-wide switch to using USB. 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 the PowerBook G4 for communication with its built-in keyboard and trackpad until early 2005.

USB

The industry-standard USB (Universal Serial Bus) protocol and its connector have become widely used for mice; it's currently among the most popular types.

Cordless or wireless

A wireless mouse made for notebook computers

Cordless or wireless mice transmit data via infrared radiation (see IrDA) or radio (including Bluetooth). The receiver is connected to the computer through a serial or USB port. The newer nano receivers were designed to be small enough to remain connected in a laptop or notebook computer during transport, while still being large enough to easily remove.

Atari standard joystick connectivity

The Amiga and the Atari ST use an Atari standard DE-9 connector for mice, the same connector that is used for joysticks on the same computers and numerous 8-bit systems, such as the Commodore 64 and the Atari 2600. However, the signals used for mice are different from those used for joysticks. As a result, plugging a mouse into a joystick port causes the "joystick" to continuously move in some direction, even if the mouse stays still, whereas plugging a joystick into a mouse port causes the "mouse" to only be able to move a single pixel in each direction.

Operation

A mouse typically controls the motion of a pointer in two dimensions in a graphical user interface (GUI). 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. (See also point-and-click)

Users can also employ mice gesturally; 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 the drag-and-drop gesture, in which:

1. The user presses the mouse button while the mouse cursor hovers over an interface object
2. The user moves the cursor to a different location while holding the button down
3. The user releases the mouse button

For example, a user might drag-and-drop a picture representing a file onto a picture of a trash can, thus instructing the system to delete the file.

Other uses of the mouse's input occur commonly in special application-domains. In interactive three-dimensional graphics, the mouse's motion often translates directly into changes in the virtual 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.

When mice have more than one button, software may assign different functions to each button. Often, the primary (leftmost in a right-handed configuration) 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, the Mozilla web 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 new tab or window in response to a click with the tertiary (middle) mouse button.

Different ways of operating the mouse cause specific things to happen in the GUI:

• 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 ternary button.
• Drag: pressing and holding a button, then moving the mouse without releasing. (Use the command "drag with the right mouse button" instead of just "drag" when you instruct a user to drag an object while holding the right mouse button down instead of the more commonly used left mouse button.)
• 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 a modifier 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's 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.

Standard semantic gestures include:

• Crossing-based goal
• Drag and drop
• Menu traversal
• Pointing
• Rollover
• Selection

Multiple-mouse systems

Some systems allow two or more mice to be used at once as input devices. 16-bit era home computers such as the Amiga used this to allow computer games with two players interacting on the same computer. The same idea is sometimes used in collaborative software, e.g. to simulate a whiteboard that multiple users can draw on without passing a single mouse around.

Microsoft Windows, since Windows 98, has supported multiple simultaneous pointing devices. Because Windows only provides a single screen cursor, using more than one device at the same time generally results in seemingly random movements of the cursor. However, the advantage of this support lies not in simultaneous use, but in simultaneous availability for alternate use: for example, a laptop user editing a complex document might use a handheld mouse for drawing and manipulation of graphics, but when editing a section of text, use a built-in trackpad to allow movement of the cursor while keeping his hands on the keyboard. Windows' multiple-device support means that the second device is available for use without having to disconnect or disable the first.

DirectInput originally allowed access to multiple mice as separate devices, but Windows NT based systems could not make use of this. When Windows XP was introduced, it provided a feature called "Raw Input" that offers the ability to track multiple mice independently, allowing for programs that make use of separate mice. Though a program could, for example, draw multiple cursors if it was a fullscreen application, Windows still supports just one cursor and keyboard.

As of 2009, Linux distributions and other operating systems that use X.Org, such as OpenSolaris and FreeBSD, support unlimited numbers of cursors and keyboards through Multi-Pointer X.

There have also been propositions of having a single operator use two mice simultaneously as a more sophisticated means of controlling various graphics and multimedia applications.

Buttons

Main article: Mouse button

Mouse buttons are microswitches which can be pressed ("clicked") to select or interact with an element of a graphical user interface.

The three-button scrollmouse has become the most commonly available design. As of 2007 (and roughly since the late 1990s), users most commonly employ the second button to invoke a contextual menu in the computer's software user interface, which contains options specifically tailored to the interface element over which the mouse cursor currently sits. By default, the primary mouse button sits located on the left-hand side of the mouse, for the benefit of right-handed users; left-handed users can usually reverse this configuration via software.

Mouse speed

The computer industry often measures mouse sensitivity in terms of counts per inch (CPI), commonly expressed incorrectly as dots per inch (DPI) – the number of steps the mouse will report when it moves one inch. In early mice, this specification was called pulses per inch (ppi). If the default mouse-tracking condition involves moving the cursor by one screen-pixel or dot on-screen per reported step, then the CPI does equate to DPI: dots of cursor motion per inch of mouse motion. The CPI or DPI as reported by manufacturers depends on how they make the mouse; the higher the CPI, the faster the cursor moves with mouse movement. However, software can adjust the mouse sensitivity, making the cursor move faster or slower than its CPI. Current software can change the speed of the cursor dynamically, taking into account the mouse's absolute speed and the movement from the last stop-point. In most software this setting is named "speed", referring to "cursor precision". However, some software names this setting "acceleration", but this term is in fact incorrect. The mouse acceleration, in the majority of mouse software, refers to the setting allowing the user to modify the cursor acceleration: the change in speed of the cursor over time while the mouse movement is constant.

For simple software, when the mouse starts to move, the software will count the number of "counts" or "mickeys" received from the mouse and will move the cursor across the screen by that number of pixels (or multiplied by a rate factor, typically less than 1). The cursor will move slowly on the screen, having a good precision. When the movement of the mouse passes the value set for "threshold", the software will start to move the cursor more quickly, with a greater rate factor. Usually, the user can set the value of the second rate factor by changing the "acceleration" setting.

Operating systems sometimes apply acceleration, referred to as "ballistics", to the motion reported by the mouse. For example, versions of Windows prior to Windows XP doubled reported values above a configurable threshold, and then optionally doubled them again above a second configurable threshold. These doublings applied separately in the X and Y directions, resulting in very nonlinear response.

Mousepads

Main article: Mousepad

Engelbart's original mouse did not require a mousepad; the mouse had two large wheels which could roll on virtually any surface. However, most subsequent mechanical mice starting with the steel roller ball mouse have required a mousepad for optimal performance.

The mousepad, the most common mouse accessory, appears most commonly in conjunction with mechanical mice, because to roll smoothly the ball requires more friction than common desk surfaces usually provide. So-called "hard mousepads" for gamers or optical/laser mice also exist.

Most optical and laser mice do not require a pad. Whether to use a hard or soft mousepad with an optical mouse is largely a matter of personal preference. One exception occurs when the desk surface creates problems for the optical or laser tracking, for example, a transparent or reflective surface.

In the marketplace

Computer mice built between 1986 and 2007

Around 1981 Xerox included mice with its Xerox Star, based on the mouse used in the 1970s on the Alto computer at Xerox PARC. Sun Microsystems, Symbolics, Lisp Machines Inc., and Tektronix also shipped workstations with mice, starting in about 1981. Later, inspired by the Star, Apple Computer released the Apple Lisa, which also used a mouse. However, none of these products achieved large-scale success. Only with the release of the Apple Macintosh in 1984 did the mouse see widespread use.

The Macintosh design, commercially successful and technically influential, led many other vendors to begin producing mice or including them with their other computer products (by 1986, Atari ST, Commodore Amiga, Windows 1.0, GEOS for the Commodore 64, and the Apple IIGS). The widespread adoption of graphical user interfaces in the software of the 1980s and 1990s made mice all but indispensable for controlling computers.

In November 2008, Logitech built their billionth mouse.

Use in gaming

Logitech G5 laser mouse designed for gaming

Mice often function as an interface for PC-based computer games and sometimes for video game consoles.

First-person shooters

Due to the cursor-like nature of the crosshairs in first-person shooters (FPS), a combination of mouse and keyboard provides a popular way to play FPS games. Players use the X-axis of the mouse for looking (or turning) left and right, leaving the Y-axis for looking up and down. Many gamers prefer this primarily in FPS games over a gamepad or joypad because it provides a higher resolution for input, so they are able to make small, precise motions in the game more easily. The left button usually controls primary fire. If the game supports multiple fire modes, the right button often provides secondary fire from the selected weapon. Games with only a single fire mode will generally map secondary fire to ironsights. In older games, the right button may also provide bonus options for a particular weapon, such as allowing access to the scope of a sniper rifle or allowing the mounting of a bayonet or silencer.

Gamers can use a scroll wheel for changing weapons (or for controlling scope-zoom magnification, in older games). On most FPS games, programming may also assign more functions to additional buttons on mice with more than three controls. A keyboard usually controls movement (for example, WASD, for moving forward, left, backward and right, respectively) and other functions such as changing posture. Since the mouse serves for aiming, a mouse that tracks movement accurately and with less lag (latency) will give a player an advantage over players with less accurate or slower mice.

An early technique of players, circle strafing, saw a player continuously strafing while aiming and shooting at an opponent by walking in circle around the opponent with the opponent at the center of the circle. Players could achieve this by holding down a key for strafing while continuously aiming the mouse towards the opponent.

Games using mice for input are so popular that many manufacturers make mice specifically for gaming. Such mice may feature adjustable weights, high-resolution optical or laser components, additional buttons, ergonomic shape, and other features such as adjustable CPI.

Many games, such as first- or third-person shooters, have a setting named "invert mouse" or similar (not to be confused with "button inversion", sometimes performed by left-handed users) which allows the user to look downward by moving the mouse forward and upward by moving the mouse backward (the opposite of non-inverted movement). This control system resembles that of aircraft control sticks, where pulling back causes pitch up and pushing forward causes pitch down; computer joysticks also typically emulate this control-configuration.

After id Software's Doom, the game that popularized FPS games but which did not support vertical aiming with a mouse (the y-axis served for forward/backward movement), competitor 3D Realms' Duke Nukem 3D became one of the first games that supported using the mouse to aim up and down. This and other games using the Build engine had an option to invert the Y-axis. The "invert" feature actually made the mouse behave in a manner that users now regard as non-inverted (by default, moving mouse forward resulted in looking down). Soon after, id Software released Quake, which introduced the invert feature as users now know it. Other games using the Quake engine have come on the market following this standard, likely due to the overall popularity of Quake.

Home consoles

In 1988 the educational video game system, the VTech Socrates, featured a wireless mouse with an attached mouse pad as an optional controller used for some games. In the early 1990s the Super Nintendo Entertainment System video game system featured a mouse in addition to its controllers. The Mario Paint game in particular used the mouse's capabilities, as did its successor on the Nintendo 64. Sega released official mice for their Genesis/Mega Drive, Saturn and Dreamcast consoles. NEC sold official mice for its PC Engine and PC-FX consoles. Sony Computer Entertainment released an official mouse product for the PlayStation console, and included one along with the Linux for PlayStation 2 kit. However, users can attach virtually any USB mouse to the PlayStation 2 console. In addition the PlayStation 3 also fully supports USB mice. Recently the Wii also has this latest development added on in a recent software update.

See also

• Computer accessibility
• Footmouse
• Graphics tablet
• Gesture recognition
• Human–computer interaction (HCI)
• List of wireless mice with nano receivers
• Mouse button
• Mouse keys
• Mouse Practice
• Pointer trails
• Pointing stick
• Repetitive strain injury (RSI)
• Rotational mouse
• Trackball

References

• Agilent Technologies (2004). ADNS-2610 Optical Mouse Sensor. (pdf format) Retrieved 2004-11-16.
• Squeak Wiki (16 March 2004). FAQ: Mouse Buttons. Revision 24. Retrieved 2004-11-17.
• Inertial mouse system, United States Patent 4787051