Computer mouse
A computer mouse (plural mice, also mouses)[nb 1] is a hand-held pointing device that detects two-dimensional motion relative to a surface. This motion is typically translated into the motion of the pointer (called a cursor) on a display, which allows a smooth control of the graphical user interface of a computer.
This article is about the item of computer hardware. For the pointer or cursor it controls, see Cursor (user interface) § Pointer.
The first public demonstration of a mouse controlling a computer system was done by Doug Engelbart in 1968 as part of the Mother of All Demos.[1] Mice originally used two separate wheels to directly track movement across a surface: one in the x-dimension and one in the Y. Later, the standard design shifted to use a ball rolling on a surface to detect motion, in turn connected to internal rollers. Most modern mice use optical movement detection with no moving parts. Though originally all mice were connected to a computer by a cable, many modern mice are cordless, relying on short-range radio communication with the connected system.
In addition to moving a cursor, computer mice have one or more buttons to allow operations such as the selection of a menu item on a display. Mice often also feature other elements, such as touch surfaces and scroll wheels, which enable additional control and dimensional input.
History[edit]
Stationary trackballs[edit]
The trackball, a related pointing device, was invented in 1946 by Ralph Benjamin as part of a post-World War II-era fire-control radar plotting system called the Comprehensive Display System (CDS). Benjamin was then working for the British Royal Navy Scientific Service. Benjamin's project used analog computers 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 what they called a "roller ball" for this purpose.[9][10]
The device was patented in 1947,[10] 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.[9]
Another early trackball was built by Kenyon Taylor, a British electrical engineer working in collaboration with Tom Cranston and Fred Longstaff. Taylor was part of the original Ferranti Canada, working on the Royal Canadian Navy's DATAR (Digital Automated Tracking and Resolving) system in 1952.[11]
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. A digital computer calculated the tracks and sent the resulting data to other ships in a task force using pulse-code modulation radio signals. This trackball used a standard Canadian five-pin bowling ball. It was not patented, since it was a secret military project.[12][13]
An older Microsoft wireless mouse made for notebook computers
Microsoft Bluetooth Mobile Mouse 3600
Operating system support[edit]
MS-DOS and Windows 1.0 support connecting a mouse such as a Microsoft Mouse via multiple interfaces: BallPoint, Bus (InPort), Serial port or PS/2.[104]
Windows 98 added built-in support for USB Human Interface Device class (USB HID),[105] with native vertical scrolling support.[106] Windows 2000 and Windows Me expanded this built-in support to 5-button mice.[107]
Windows XP Service Pack 2 introduced a Bluetooth stack, allowing Bluetooth mice to be used without any USB receivers.[108] Windows Vista added native support for horizontal scrolling and standardized wheel movement granularity for finer scrolling.[106]
Windows 8 introduced BLE (Bluetooth Low Energy) mouse/HID support.[109]
Multiple-mouse systems[edit]
Some systems allow two or more mice to be used at once as input devices. Late-1980s era home computers such as the Amiga used this to allow computer games with two players interacting on the same computer (Lemmings and The Settlers for example). 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 requires cooperation of users or applications designed for multiple input devices.
Multiple mice are often used in multi-user gaming in addition to specially designed devices that provide several input interfaces.
Windows also has full support for multiple input/mouse configurations for multi-user environments.
Starting with Windows XP, Microsoft introduced an SDK for developing applications that allow multiple input devices to be used at the same time with independent cursors and independent input points. However, it no longer appears to be available.[110]
The introduction of Windows Vista and Microsoft Surface (now known as Microsoft PixelSense) introduced a new set of input APIs that were adopted into Windows 7, allowing for 50 points/cursors, all controlled by independent users. The new input points provide traditional mouse input; however, they were designed with other input technologies like touch and image in mind. They inherently offer 3D coordinates along with pressure, size, tilt, angle, mask, and even an image bitmap to see and recognize the input point/object on the screen.
As of 2009, Linux distributions and other operating systems that use X.Org, such as OpenSolaris and FreeBSD, support 255 cursors/input points through Multi-Pointer X. However, currently no window managers support Multi-Pointer X leaving it relegated to custom software usage.
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.[111]
Speed[edit]
Mickeys per second is a unit of measurement for the speed and movement direction of a computer mouse,[96] where direction is often expressed as "horizontal" versus "vertical" mickey count. However, speed can also refer to the ratio between how many pixels the cursor moves on the screen and how far the mouse moves on the mouse pad, which may be expressed as pixels per mickey, pixels per inch, or pixels per centimeter.
The computer industry often measures mouse sensitivity in terms of counts per inch (CPI), commonly expressed 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).[61] The mickey originally referred to one of these counts, or one resolvable step of motion. 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. As of 2007, 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, an example being the Windows platforms, this setting is named "speed", referring to "cursor precision". However, some operating systems name this setting "acceleration", the typical Apple OS designation. This term is incorrect. Mouse acceleration in most mouse software refers to 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, with good precision. When the movement of the mouse passes the value set for some threshold, the software will start to move the cursor faster, 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.[113]