Mouse (computer)

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A three-button mouse (the mouse wheel is usually also a button).

A computer mouse ( colloquially also called a mouse ) is an input device ( command transmitter ) in computers . The very first prototype was built in 1963 based on drawings by Douglas C. Engelbart ; Since the mid-1980s, the mouse, together with the monitor and keyboard, has been one of the most important human-machine interfaces for almost all computer activities . The development of graphical user interfaces has the computer mouse to today virtually any desktop - PC made available standard input device.

The movement of the mouse, carried out by hand on the workstation - if necessary with a suitable surface such as the mouse pad - is recorded by a sensor in the mouse, digitized and transmitted to the connected computer via an interface. The operating system converts this two-dimensional movement information into a similar movement of the mouse pointer on the screen . By actuating the buttons or additional elements of the mouse, the user can perform various actions in the operating system or application program. The introduction of the computer mouse can be seen as a major breakthrough in improving the usability of computers. In 2005, it is estimated that more than a billion mice were sold worldwide.

The alternatives are to operate the computer via a trackball , trackpoint , touchscreen , touchpad or graphics tablet .


The very first prototype of a computer mouse was built in 1963 by William English based on drawings by Douglas Engelbart.
The Xerox Alto's mouse, 1973.
Trackball control Telefunken in the Computer History Museum
In 1984 the Apple Macintosh appeared, which came with a mouse as the primary input device. This was the first time that it became more widespread. On the left the Macintosh mouse from 1984 in the original beige, which was later replaced by the "platinum gray".
First Microsoft mouse (1983)

In 1963/1964 a team around Douglas C. Engelbart and William English worked at the Augmentation Research Center (ARC) of the Stanford Research Institute (SRI) on various experimental pointing devices, including a computer mouse. In December 1968 it was presented to the public at the fall meeting of the American Federation of Information Processing Societies (AFIPS). It received little attention because graphical user interfaces were not yet in place and the people who worked with computers were familiar with entering keyboard shortcuts. Engelbart applied for a patent on June 21, 1967 for the principle based on two wheels at right angles to one another, which was assigned on November 17, 1970 as patent US3541541.

On October 2nd, 1968, shortly before Engelbart's presentation of his mouse, the German Telefunken released a new input device for their TR-440 computers , called the "Trackball control for the SIG-100 on the TR-86" (RKS 100-86 for short) was designated. The inventor of this control was Rainer Mallebrein , it was developed around 1966. As early as May 1966, Telefunken advertised the trackball control in a brochure for the TR-440. Even if it is unclear who first came up with the idea for a mouse, Telefunken is in any case the first company to produce such a mouse commercially and which, unlike Engelbart's mouse, allowed it to be freely positioned using the ball. The principle remained identical in all subsequent ball mice.

The Engelbart mouse was further developed in the 1970s at the Palo Alto Research Center ( PARC ) of the Xerox company . In 1971 William English left SRI and moved to Xerox PARC. There he developed a ball mouse that is identical in principle to the Mallebrein's mouse (ball, position coding by two rotary encoders ). It was first used in 1973 on the Xerox Alto , which also had a graphical user interface for the first time . Through his work at PARC, Niklaus Wirth was also encouraged to develop a graphically oriented workstation with mouse operation in the course of his further work at ETH Zurich . The Lilith was introduced in 1980. The mouse was used commercially in the Xerox Star computer in 1981 , but the system was not commercially successful because the mouse cost $ 400 and the corresponding interface in the computer was $ 300.

Computer manufacturer Apple licensed this technology when Steve Jobs bought the rights from Xerox for $ 1,000 and commissioned the Californian design and engineering firm Hovey-Kelley Design (now IDEO ) to develop an improved, industrial-grade mouse for $ 25. The ball mouse developed by Apple and IDEO became the predominant principle of operation for mice during the 1980s and 1990s. Apple brought this mouse onto the market in 1983 together with the Lisa computer . Due to its high price, this was not a market success. The successor model, the Macintosh (SE series) introduced in 1984 , was successful. For the first time in PC history, Lisa's human-machine interface was based on this mouse, so exclusively that the computer was practically impossible to operate without a mouse. The fact that the Apple Lisa represented a milestone with its mouse operation is also clear from an enthusiastically written experience report by a computer editor from 1983:

“The real hallmark of Lisa is the 'mouse'. This small hand-held device, connected to the computer by a thin cord, is Lisa's 'man / machine interface'. With the trackball and the button, the mouse enables 'intuitive' operation. By rolling on the tabletop, the cursor is guided on the screen, a command word or a symbol is 'clicked' and you have given Lisa an order without touching the keyboard or having to master complicated command languages. "

Even before the Macintosh appeared, the London Sunday Times saw "the mouse come out of its hole" in January 1983:

“The mouse plague is about to infect the world of microcomputers. Fortunately, they are friendly creatures who are supposed to help guide the user through the software jungle. The latest and most spectacular creation of the mouse can be found in Lisa, the long-awaited office computer that Apple introduced last week. When it […] comes on the market in the summer, the manager should only need 20 minutes to learn to use the Lisa, compared to 20 hours with a normal microcomputer. "

- The Sunday Times : Clive Cookson, "New aid: A mouse to get out of a hole," January 25, 1983, translated from English

In 1985, a spin-off from the École polytechnique fédérale de Lausanne (EPFL; Eidgenössische Technische Hochschule Lausanne), the Logitech company , launched the first popular three-button ball mouse LogiMouse C7 with an RS-232 connection. With the introduction of the PS / 2 systems by IBM in 1987, mice with a PS / 2 connection were introduced. In Germany, too, IBM often referred to the mouse as a "pointing device".

In 1980 the development of optical mice began . Steve Kirsch at Mouse Systems and Richard Francis Lyon at Xerox developed different approaches. Their breakthrough came with cheap and high-performance chips for image processing . At the end of the 1990s, optical mice began to replace mice based on ball mechanics. From the end of 1998 the first mice appeared that could be connected to the computer via the USB port specified by Intel in 1996 and operated in Windows 95 (OSR2.1), Windows 98 on PCs or MacOS on Apple iMac: Primax Navigator, Logitech pilot.

The cable, which sometimes restricts freedom of movement, led to the development of wireless mice. In 1984 Logitech introduced a mouse based on infrared technology . Wireless mice that communicate with computers via radio have been available since 1991 . At the end of 2002, Microsoft and Logitech presented a mouse that communicates with the PC via Bluetooth using an HID profile, and since 2003 the connection can also be encrypted using a Belkin product .

In 1995, Genius presented the Mouse Systems ProAgio and the Genius EasyScroll, which had an additional scroll wheel between the two mouse buttons , for example to allow faster scrolling up and down within a window. Since the Intellimouse introduced by Microsoft in 1996 and the support within the Microsoft software, such mice have had a higher market share.

Sun Microsystems has had laser mice for Sun Sparc workstations since 1998 . In autumn 2004, Logitech and Agilent Technologies introduced the first laser mouse, the Logitech MX 1000 Laser, to the personal computer market. The MX1000 achieved an image processing rate of 5.8 megapixels / second at a resolution of 800 dpi. Laser mice from other manufacturers with more than 5600 dpi are now also available, for example the Razer Mamba, a mouse for computer games (English: gaming mouse).

The first mouse from Fujitsu - the M440 ECO - has been available since 2011 , in which environmental aspects play a role (housing made from 100% ecological plastic and PVC-free cable). The M440 ECO is similar to a conventional standard mouse in terms of durability and ergonomics. Since 2012 the association Nager IT e. V. even has a Fairtrade mouse. This is not only produced in a particularly ecological way, but social and ethical aspects are also taken into account wherever possible in the entire supply chain. The mouse from Nager IT is considered by experts to be the most ecological and “fairest” mouse in the world. It is conceived as a project with the aim of stimulating imitation and showing how socially and ecologically a mouse that is suitable for everyday use can be produced. There are also from various niche manufacturers such. B. wooden or bamboo mice, but where criteria such as socio-ethical production and environmental protection are irrelevant or ergonomics and durability leave much to be desired.


Application principle

The user moves the mouse on a smooth surface and the movement information is transferred to the computer. Operating system routines are used to move a marker ( mouse pointer ) on the screen according to the mouse movement. This graphic marking is usually shown as a small arrow.

The mouse is equipped with buttons that transmit an activity that can be registered for the corresponding software at the touch of a button (mouse click). In the event of such an event , the current screen coordinates are usually calculated and a corresponding reaction triggered. For example, a user can point to a file icon and select and activate it with the push of a button. The program registers this and highlights this file symbol graphically. In a word processing program , a user can move the mouse pointer in the text and place a cursor in it by pressing a key . When the user starts typing, the text is inserted at that point.


Inside view:
1. Mouse ball
2. Perforated disks
3. LED (light source of the light barrier )
4. Button
5. Optical sensor (receiver of the light barrier)
Functional representation of an optomechanical mouse:
1. Moving the mouse causes the ball to rotate.
2. The X and Y axes take over the respective part of the movement.
3. Perforated disks are rotated.
4. Infrared LEDs shine through the perforated disks.
5. Sensors receive light pulses that are converted into X and Y speeds.
Underside of an optical wireless mouse

A distinction can be made between different methods of recording mouse movement:


The first mice worked with mechanical contacts. In the very first generation, sliding contacts were still used to determine coordinates, which were subject to heavy wear, but can be evaluated in a very energy-saving manner.


A little later, optomechanical mice were common, in which the mouse movements are converted into electrical signals via a trackball, two perforated disks and associated light barriers . The rolling movement of the ball is transmitted via two rollers to two perforated segment discs, whose direction of rotation and speed are used to generate electrical impulses ("Mickies") via incremental encoders with small light barriers. The relative coordinates for displaying the mouse pointer are calculated in the computer with appropriate software (mouse driver). Ball mice, however, are prone to soiling because the ball, a steel ball usually covered with rubber, repeatedly pulls particles into the inside of the mouse and these mainly stick to the mechanism, which can reduce the precision and repeatability of the mouse. Strong sunlight can also affect some mice with slightly translucent housings by interfering with the light barriers. The advantage over optical mice with an image processing processor is the lower power requirement (25 mA to 100 mA for an optical mouse) and the fact that it can also be used on a transparent surface such as a glass plate due to the design.

Optical with light emitting diodes

Newer generations of mice illuminate the surface on which the mouse is moved with a built-in light source, for example a light-emitting diode, and record the reflections with an optical sensor. A built-in microprocessor calculates the direction and speed of movement of the mouse from the differences between successively recorded images. This type of mouse is called an “ optical mouse ”. Failure phenomena due to dirty balls and above all roll axes can no longer occur due to the design. On the other hand, the optical signal is sometimes misinterpreted in the case of fine movements even on well-structured documents and the pointer is moved incorrectly.

The first mice of this type required special mouse pads on which a grid or points were drawn that the optical sensor could use for orientation (system by Steve Kirsch, Mouse Systems). With the higher performance of the microprocessors built into the mice, more computationally intensive algorithms can now be used for image processing. This is how modern optical mice work on almost all documents. Only areas that have very little or no structure, e.g. B. mirrors, glass and many painted surfaces are unsuitable in principle. The high precision of modern optical mice is particularly noticeable in graphic applications and computer games .

Optical with laser diodes

The laser mouse is an improved variant of the optical mouse. Instead of the normal light-emitting diodes, a laser diode based on infrared technology is used as the light source. Due to the speckle effect, this results in a better contrast even on very smooth surfaces, but transparent surfaces remain problematic.

BlueTrack technology

The BlueTrack technology, developed and presented by Microsoft in 2011 , is intended to replace the previously common methods of motion detection. A large blue light source below the mouse should be able to create an image with better contrast of the surface in combination with the optical sensor and the pixel geometry from Microsoft, so that more precise tracking is possible. This technology should work on other, so far unsuitable surfaces. Transparent glass or reflective surfaces continue to be the sore point of all non-mechanical techniques.

Darkfield technology

The Darkfield technology developed by Logitech uses laser diodes for motion detection, but the principle of dark field microscopy is also used to detect even dirt on the surface and minimal irregularities and to use them to detect motion. The advantage of this technology is that it can be used on previously unsuitable surfaces such as glass or other reflective surfaces with a comparatively high level of reliability.


Depending on the motion sensor used (mechanical-electrical, optomechanical, optical with LED or laser diode), the sensitivity of the mouse differs, i.e. the distance that the mouse must travel on the surface in order to cover a certain distance with the mouse pointer on the screen . A high level of sensitivity results in a short travel path on the surface. This is influenced by the resolution in dpi that is sometimes given for mice : the more points that can be resolved on a certain distance, the more sensitive the mouse is.

Some operating systems and some programs offer the possibility of individually influencing the sensitivity. In addition, the acceleration can be set in the newer operating system (so-called "mouse acceleration") if the movement speed is evaluated in addition to the distance covered. When moving over large areas, it is helpful if the long distance can be covered with a quick movement and the exact approach to the desired point can then be carried out at normal speed.


In addition to the ability to transmit a two-dimensional position, actions can be triggered with mice using buttons. The mouse buttons used to trigger a mouse click usually conceal micro buttons that close a contact when a certain force is exceeded. This change is transmitted to the computer as a bit in a part of the mouse protocol and triggers an associated action via the mouse driver, operating system and application program. The buttons often have a kind of cracking frog effect : If the required force is exceeded, the user receives both tactile and acoustic feedback of the actuation (hence the term mouse click).

Engelbart's first mouse only had one button. Xerox designed a variant with three buttons early on. Apple only used one key again. Many mice at Unix workstations had three buttons. For a long time, mice with two buttons were dominant in the PC sector. Younger models often have additional buttons that have permanently programmed functions or whose functionality can even be freely programmed.

Another development was the roll wheel (wheel mouse). This wheel usually has the function of facilitating easy scrolling , but it can also be assigned differently. On most models these days, the scroll wheel is clickable and thus functions as the middle mouse button. Some models have two wheels to allow horizontal and vertical scrolling at the same time.

Optical wheel mouse circuit board

Standard assignment of the key functions

The buttons are queried by the system via event numbers (button). A typical standard assignment under Linux and Windows is:

Button (event-no) button Meaning / function
1 left button normal click (selection / positioning)
2 middle button (often on the wheel) Middle click
3 right button Right click (mostly context menu)
4th Wheel - up mostly scroll-up
5 Wheel - down mostly scroll-down
6th Wheel - left pressure mostly scroll left
7th Wheel - right pressure mostly scroll-right
8th left side / or lower left button Special function: e.g. B. Back in the browser
9 right side / or left upper button Special function: e.g. B. Forward in the browser

Additional mouse buttons are usually useless until a corresponding device driver is installed.

Wireless mice

Wireless mice, like wireless keyboards, no longer transmit their information through the sometimes annoying cable. Instead, the data is transmitted from the mouse to a base station via infrared (rarely) or radio (e.g. Bluetooth or another ISM band [2.4 GHz is the most widely used today]). If the base station is not already permanently installed in the computer, the signal is then forwarded to the computer by cable via the serial , PS / 2 or USB interface.

Wireless mice need their own power supply, usually from batteries or accumulators. This results in the mouse being slightly heavier and the occasional battery change or recharging necessary. According to the manufacturer, newer, higher-quality models can last for months to years without changing batteries or recharging. While some are placed in a charging station for charging and thus cannot be used while charging, there are also models that are charged via a cable and can also be used while charging. Wireless mice without an internal power supply are also available, which are powered by induction from a specially supplied mouse pad connected to a USB port.

If the data is not encrypted, wireless mice can usually be bugged relatively easily and sometimes have a slightly longer response time than wired models.

Gaming mice

Gaming mouse with side buttons

This type of mouse is specially designed for computer games . A basic feature of gaming mice is the installation of a high-performance optical sensor such as B. PixArts model PMW3360. This high-resolution sensor has a point density of 12,000 DPI, which can usually be set using software or hardware. The shape of the mouse is either ergonomic or ambidextrous, with the ambidextrous shape being symmetrical and suitable for right and left-handed users. The ergonomic shape, on the other hand, is intended to provide a natural holding position for the user's hand and is intended for either right-handed or left-handed users. Some gaming mice, which were primarily designed for MMORPGs , have a higher number of side buttons to simplify the operation of numerous capabilities. In the shooter genre, a lot of emphasis is placed on the weight of the mouse, with a low weight relieving the wrist during prolonged use and fast movements being made with less effort. There is a diverse selection of products among the gaming mice, which differ in quality and price. Gaming mice are often used for their extravagant functions such as B. classified RGB LEDs . However, these are not critical to the actual performance of the mouse.

Interfaces for the electrical connection

Since the mouse only found its way to IBM PC-compatible computers in the late 1980s, a suitable interface had to be found there, in contrast to computers that had a mouse in their basic concept, e.g. Macintosh, Amiga, Atari ST being found.

Bus mouse connection to PC plug-in cards

Initially, mice for IBM-compatible computers were operated using their own interface cards ("bus mouse"). The pin assignment of the mouse cable was not standardized, so the mouse and card had to match.

Serial interface according to RS-232

A common method was the connection to the serial port ( RS232 ) via a nine- or 25-pin D-Sub connector. This serial interface was originally developed for remote data transmission with teleprinters, modems and acoustic couplers . Since the mouse is a simple device with slow data transmission, which only transmits data for coordinate information and the status of the keys and could also receive its power via the interface using a handshake pin that was not used for this purpose, this interface was a very long-lasting solution in which the mouse can also be connected without any problems during operation. This serial solution kept in PCs since the mid-1980s, more than a decade and disappeared until 1996 gradually with the advent of ATX - motherboards and PS / 2 mouse (see below). A disadvantage from the manufacturer's point of view is the high voltages of +/- 12 V used for RS-232 instead of the 0 V / 5 V that is more common inside the PC, which increases the circuit complexity. Early models even required their own power supply.

Manufacturer's own interfaces

Early Apple computers in the Apple II series were designed without a mouse. For this only a bus mouse concept with a special plug-in card for the mouse connection was used. The Apple Macintosh computers provided their own ( proprietary ) connection for the mouse when they were first introduced . Initially (original Macintosh, Macintosh 512 and Macintosh Plus) the unprocessed signals of the axes and the key were transmitted via a nine-pin D-Sub connector, which was replaced in 1987 on the Macintosh II and Macintosh SE by the more universal Apple Desktop Bus (ADB) . The ADB was used to connect the mouse to the keyboard and the keyboard to the computer with a second ADB. Other small devices were also connected via ADB. The ADB was used until the Power Macintosh G3 of 1998, when Apple replaced the ADB with the USB interface.

In SUN Unix workstations, too, the mouse was connected to the keyboard until around 2003, and both devices were connected to the workstation with a common cable (SUN Ultra).

Similar to early Apple models, the Commodore company used an interface for their Amiga computers that transmits unprocessed signals via a nine-pin D-Sub connector. The pin assignment was based on the Atari 2600 “de facto standard” for joystick sockets, so that the same sockets could support mice and joysticks . A mouse was developed for the Commodore 64 and Commodore 128 , which initially had no mouse and therefore no dedicated receiver hardware in the device, which transmitted its signals analog via the paddle interface ( Commodore 1351 ) and a mouse , which transmitted its signals digitally via the joystick interface ( Commodore 1350 ).

PS / 2 interface

Microsoft mouse with PS / 2 interface

With IBM-compatible computers, with the widespread appearance of mouse-controlled operating systems with the PS / 2 connection, a separate interface only for the mouse prevailed. This was already defined by IBM in 1987 in the technical reference manuals for the PS / 2 system. The transfer protocols and the pin assignments of the keyboard and mouse are identical: It is a synchronous, serial protocol that was originally developed specifically for computer keyboards and works with a 5-volt supply voltage.

Unlike the serial and USB interfaces, the PS / 2 interface is not hot-pluggable : a mouse must be connected to it when the computer is switched on in order to be able to use it. Unplugging during operation regularly leads to system halt and can even destroy the interface. Especially portable computers with a PS / 2 interface often support hotplugs.

Even if the pin assignment for basic communication between keyboard and mouse is identical, the connections are clearly assigned. A mouse will not work on the keyboard port even if the connector fits. Some of the other pins have a special assignment, for example on the keyboard to turn off the computer. To make this clearer, a color coding of the connections has become established over time: the connector and socket are turquoise for the mouse and purple for the keyboard.

USB interface

Today, the universal USB connection for mice and other peripherals for IBM-compatible computers, Unix workstations (SUN, IBM) and for Apple Macintosh computers has largely prevailed over the PS / 2 connection. Modern PCs rarely, notebooks almost never, have a PS / 2 connection. In addition to the ground and 5 V supply voltage line, two data lines are used for the transfer with the USB connection, via which data is transmitted differentially. In addition, devices to the USB port by the order, are prepared in which the compounds during the mating process (first mass and voltage), are designed to remove or re-connected during operation to ( hot plug ).

Communication with the connected computer

Regardless of the physical interface used , serial data transmission takes place between the computer and the mouse connected to it. Various methods of transmission are used, which are referred to as protocols. Depending on the protocol used and the mouse, the corresponding mouse driver must be installed in the operating system on the computer, which can also be used to make adjustments for the sensitivity and acceleration of the mouse if necessary.

Bus mouse

InPort ISA expansion card from Microsoft
A computer mouse from 1986 with a mini-DIN 7 connector

In the case of a bus mouse or bus mouse, the complete electronics for decoding mouse movement and key actuation are located on a PC plug-in card for the ISA bus. Nine signals are transmitted via a nine-pin mini-DIN adapter (also called a Hosiden adapter). In addition to the ground potential, these are the contact signals of the three mouse switches and two each for the offset light barriers of the rotary sensors for the X and Y directions. These mice were as Logitech, Microsoft and ATI together with the appropriate ISA bus - plug-in cards available today and are hardly in operation.

Mouse with serial interface according to RS-232

For mice with a serial interface according to RS-232 , connections with nine or 25-pin D-Sub sockets on the mouse cable can be used. The signals mass, RxD, TxD, RTS, DTR are used, CTS and DSR are not used, but must not be bridged either. The positive supply voltage for the light-emitting diodes of the motion sensors and for operating the interface is obtained in the mouse from DTR and RTS; a reset is also carried out via DTR. TxD supplies the negative voltage. The signal voltages used are between −12 V and +12 V according to RS232. The data is transferred from the mouse to the computer asynchronously at 1200 bit / s via the RxD connection with every change of status, e.g. by mouse click or movement.

  • With the Microsoft mouse protocol, the data is transmitted in three consecutive bytes, containing start and stop bits, two bits for the two mouse buttons and the values ​​for X and Y movement, each nested in a seven-bit value. The data is transmitted with seven data bits and two stop bits or eight data bits and one stop bit. The X and Y values ​​each represent the change compared to the previous version and are not absolute values ​​or positions. These counters are reset after they have been transferred to the computer.
  • Logitech uses a previously unused bit in the Microsoft mouse protocol to transmit the status of the third mouse button.
  • In contrast to the Microsoft mouse protocol, the Mouse Systems mouse protocol also uses a further previously unused bit for the third mouse button and transmits the movement in five instead of three bytes without interleaving; the two additional bytes four and five already contain change values ​​compared to those in bytes two and three transmitted X and Y values. The data are transmitted with eight data bits and one stop bit.
  • There are mice that can be toggled between the Microsoft and the Mouse-Systems mouse protocol using a switch on the underside of the mouse. Under X11 , a missing switch to switch to mouse systems mode can possibly be replaced by pressing the left mouse button during booting.
Four-core cable of the PS / 2 interface

Mouse with PS / 2 interface

A PS / 2 mouse is connected to an often green six-pin mini-DIN connector that is comparable to the PS / 2 keyboard connector and is controlled via a serial, bidirectional, synchronous protocol. This task is carried out by the keyboard controller or the input device controller.

An IBM-compatible PCs connected mice typically use no more than four physically connected wires: 5 volt supply voltage (maximum 275 mA load), mass , a data and a clock line. The clock and data lines are controlled by the computer and mouse side via open collector drivers, the quiescent level is 5 volts. The mouse and computer can pull each of the two lines to the level of 0 V. The side that pulls the clock line to 0 volt level can transmit valid data over the data line. The clock signal between 10 kHz and 16.7 kHz is generated by the mouse. It is only allowed to send data if the clock signal was not set to 0 V by the computer to interrupt communication.

The transmission takes place with a start bit (always 0), eight data bits ( least significant bit first), odd parity and a stop bit (always 1), data is written to the data line when the clock line is high and read by the computer when the clock level drops. Similar to the Microsoft protocol, data is transmitted in three eight-bit characters, but without interleaving. In addition to the data contained in the Microsoft protocol for serially connected mice, a sign and an overflow bit are also transmitted for the X and Y values. The computer can transmit various commands to the mouse and set it to various transmission modes: "Streammode" (standard: every change is transmitted), "Remote Mode" (changes are only transmitted on request), "Reset Mode" and "Wrap Mode" (Echo mode)).

The resolution (steps / mm), sampling rate (samples / s) and scaling (enlargement factor of the transmitted counter readings) of the mouse can also be influenced by commands from the computer, more precisely: from the keyboard / mouse controller. A connected PS / 2 mouse is recognized while the IBM-compatible PC is booting and normally cannot be removed, reconnected and used during operation, so it cannot be hot-plugged.


For the use of the Intellimouse, Microsoft has extended the PS / 2 protocol to a four-byte packet format for the IMPS / 2 protocol. In the fourth data package, the movement information of the scroll wheel and the states of the two additional buttons are transmitted. The Intellimouse behaves like a PS / 2 mouse when it is switched on, but transmits a different device ID after a reset. This causes the mouse driver to process the four-byte packets then transmitted.

PS / 2 serial mouse

Some PS / 2 mice can also be operated on a serial port using an appropriate adapter: the PS / 2 serial mouse. However, since these adapters cannot switch between the different levels and protocols, the electronics in the mouse must recognize which connection is being used and adapt to it. That would be possible via the supply voltage, which is higher at the serial RS-232 connection.

Mouse on the USB port

In contrast to PS / 2 mice, mice connected to the USB bus no longer use a proprietary protocol, but a bus protocol standardized by the USB Interface Forum. The data is transmitted serially, differentially on the two data lines with sync signal, NRZI coding and bit stuffing , so a separate clock line is not required, as is the case with PS / 2 mice.

The USB device driver must ensure that the status of the USB slave client, in this case: the mouse , is often enough (see USB software architecture ) via a USB driver, the driver of the USB host controller and the USB host controller itself , is queried. The mouse is addressed as a "Human Interface Device" (HID) device via a seven-bit long identifier assigned by the USB host controller after identification (see USB configuration ) and operated as such in accordance with the USB 1.0 standard. During initialization, it informs the host controller or the underlying USB driver from its buffer memory 0 about its capabilities and properties (number: maximum four, direction: in or out, query frequency, the "sample rate", and size of the buffer memory of the so-called endpoints: maximum 64 bytes, device type, manufacturer, "class code", device ID, protocol, required bandwidth and others). This saves the information and reserves the corresponding time slots on the bus. Then the host controller queries the data to be transmitted from the endpoints every 10 ms on behalf of the device driver, who queues the USB host controller driver, in interrupt transfer mode; the transfer takes place with a maximum of eight bytes per transfer Checksum secured (CRC16) from the mouse to the computer. The end point therefore actually forms a memory area in the host device (the mouse) that can be viewed jointly by the host controller (the computer) and the host device (the mouse) and that is regularly read by the computer within a guaranteed time interval. If the BIOS of IBM-compatible PCs offers legacy support, USB mice can be used like PS / 2 mice by emulating the 8042 keyboard controller via the USB hub controller. Since the introduction of the Apple iMac , USB has been the standard input device connector for Apple Macintosh computers.

Mouse for USB or PS / 2 connection

USB – PS / 2 mouse adapter

Comparable to the PS / 2 serial mice, there are also those that can be operated either via a USB or a PS / 2 connection. There are adapter plugs that are supplied with the mouse and convert from the USB port to the PS / 2 port or vice versa. The inclusion of an adapter allows conclusions to be drawn about the capabilities of the mouse, because here too, based on the given circumstances, it must decide whether it behaves like a PS / 2 mouse or like a mouse connected to the USB port. Criterion can be, for. B. the behavior of the data lines after switching on: With a PS / 2 computer one can assume that at a certain point in time after switching on to transmit the reset command, the clock and data line will be switched over according to a certain procedure, on USB is assumed to be differential data transmission, which does not correspond to the PS / 2 procedures. A mouse or keyboard that is delivered without a USB-to-PS / 2 adapter can usually not be operated on a PS / 2 connection even with a retrofitted adapter, because the device must support this function from the outset.

Mouse on the Apple Desktop Bus

With the Apple Desktop Bus (ADB), Apple had already followed a similar concept to the USB in 1986, albeit on a smaller scale. A four-pin mini-DIN connector is used, similar to an S-video connector. Usually three connections are occupied: 5 V supply voltage, ground and the data line. A fourth, additional connection to the power supply unit of the computer was not used for mice. The connection is not intended for the hotplug function because the ADB must be initialized after a mouse has been plugged in to function properly. This initialization is only carried out automatically by the operating system during the start-up process, but can also be carried out using an additional program without restarting the computer. In the standard version, the plug connection is only designed for a maximum of 400 plugging processes. This is very little compared to today's USB connections. Up to 16 devices could be addressed, the data transfer rate is limited to 10 kBit / s. It is controlled exclusively by the computer and the devices (in this case the mouse) only return data when queried via a defined memory area (register, comparable to the end point). The definition also allowed the same addresses on the bus, which occasionally led to problems.


Hardware dependent

With the first IBM-compatible PCs, the mouse had to be assigned hardware-dependent resources. The plug-in card of the bus mouse usually requires the assignment of one of the few available interrupts as well as a suitable I / O address range ( port ). The setting is made via jumpers or something more modern in the BIOS of the computer.

Serial mice are usually assigned their own serial, physically available interface including an interface speed and protocol (e.g. 8N0, 7N1). This is done in the same way as the specification of the necessary, suitable mouse driver with its options via configuration files.

In the case of PS / 2 mice and USB mice, this type of information is not required, since these interfaces already provide working specifications in the computer hardware or based on the protocol used. With hardware and operating systems delivered since the late 1990s at the latest, the user rarely has to deal with such hardware-related details.

Software dependent

On the other hand, the number of setting options for the mouse driver and operating system has increased significantly. Mention should only be made of the sensitivity setting of the mouse already described, the time interval for double-clicks and the assignment of program-dependent functions to additional mouse buttons. However, these are largely only adjustments to make the use more pleasant for the user. The basic function of the mouse (i.e. pointing and clicking) is usually given even without such adjustments.


IBM PS / 2 two button mouse (1987)

Every common graphical user interface for computers that currently exists for end users can be operated with the mouse. The usual number of mouse buttons and other elements for interaction (scroll wheel) has changed over time:

  • One button: The original Macintosh user interface was designed for simple operation, in which the user could operate the entire device with one mouse button. Even today, Apple mice are delivered with a button, with the entire surface of the mouse working as a button. Additional context-related program functions are triggered with the help of special keys on the keyboard ("modifiers") parallel to the mouse click. However, the Mac OS X operating system also supports multi-button mice. In most Apple programs, the second key is used for the context menu . In the case of one-button mice, this is called up via a Ctrl mouse click.
  • two buttons: All devices that were used in connection with the Microsoft Windows , IBM OS / 2 , Atari TOS and AmigaOS operating systems were initially equipped with two buttons. The left button was mostly used for the selection, while the second, right button triggers a special function. In particular, the context menu, which was introduced on a large scale for the first time with Windows 95 and offers a selection of modifications for the activated object, is activated via this second key. With Atari-TOS, the second button initially had no other standard function and different meanings depending on the program. With the AmigaOS the right mouse button was used for the menu bar. The two mouse buttons can be swapped in most operating systems, e.g. for left-handers. The simultaneous click with both buttons could also be evaluated with the mentioned operating systems, but this was only used by a small part of the available software.
  • Older model of a three-button Sun Microsystems mouse and mouse pad
    three buttons: With the operating systems from the workstation world such as X Window System and RISC OS as well as with the Xerox Alto three mouse buttons were used. The purpose of the third button is inconsistent in different programs. In RISC OS, the context menu is called with the middle mouse button; in the X Window System, it is used to insert the text previously marked with the left mouse button.
  • modern gaming mouse with several additional buttons
    four or more keys: The additional keys can usually be assigned functions such as double-click, key combinations or the start of a program by the user. Sometimes some of the keys have a fixed function, e.g. B. changing the resolution of the mouse (see section Sensitivity ). They are usually on the side and / or behind the scroll wheel. In contrast to the functions often provided by the operating system in mice with one to three buttons, no standard has yet been established here.

At the end of the 1990s, the so-called " scroll wheel " became established in computer mice . It is usually located between the two mouse buttons and is used to scroll up and down the window content. It is also sometimes used to set graphically simulated sliders. Many mice combine the scroll wheel with the function of a third button, so that pressing the wheel sends the corresponding signal to the computer. In some models, the scroll wheel can also be moved to the left or right to enable horizontal scrolling of the window content using the mouse. In July 2005, after almost three decades of consistent one-button mouse philosophy, Apple presented the Mighty Mouse USB multi-button mouse for the first time, which is compatible with the Windows XP and Mac OS X operating systems and, in addition to three additional, programmable buttons, has a new 360- Degree scroll ball that allows free vertical and horizontal scrolling (the latter only in Mac OS X).

The average computer user has contact with the mouse for about half of his working time. A Dutch study published in 2010 found the following average time shares:

  • 53% of the time the computer is used the mouse is used,
  • The keyboard is used 25% of the computer's time.

Mouse actions

By moving the mouse, the mouse pointer can be moved to the desired location, and the user can trigger actions by pressing a mouse button. The function of the mouse buttons and the mouse movement in a program or operating system can often be modified depending on the operating system by pressing additional keys on the computer keyboard, for example using the Apple key, the Shift, Ctrl or Alt key. There are essentially three different mouse actions:

Mark icons with the mouse. The tip of the white, arrow-shaped mouse pointer shows the "virtual" position of the mouse.
  • the click: A mouse click refers to pressing and immediately releasing the mouse button without moving the mouse in the meantime.
  • the double-click: pressing the mouse button twice in quick succession without moving the mouse. Some programs also support three to five clicks. However, due to the difficult execution, the latter did not prevail. With most operating systems, the time interval can be set in which the second key actuation must take place in order to be accepted as a double click. Sometimes a threshold value can also be set for how far the mouse can move between the two clicks, since a complete standstill can hardly be achieved with highly sensitive mice.
  • dragging: the mouse button is pressed down and held there while the mouse is moved. The key is only released at the end of this dragging process for actions such as drag & drop or the marking of text.

Other mouse actions are:

  • Right click: Clicking the right mouse button is used synonymously for functions of the second mouse button and usually opens a context menu . In the left-handed setting (see below) this is the "left click".
  • In an X11 interface under Unix, you can toggle a marking in the text between a word, a sentence (up to the next comma or point) or paragraph (up to the next blank line) and load it into a buffer by multiple clicks.
  • Then, with a click of the middle mouse button under X11, the marked text segment can be inserted from the buffer in another X window. With two-button mice, this middle mouse click can be emulated depending on the operating system or driver by simultaneously pressing the right and left mouse button.
  • Pointing: moving the mouse pointer to a specific position without pressing a key.
  • Driving over is also an action that can be evaluated in modern operating systems. When pausing at a screen position, the program often outputs so-called " context-sensitive help ": A short help text is displayed for the element below. Then there is often a small yellow window with further explanations, a so-called “ tooltip ”, attached to the mouse pointer .
  • Mouse gesture visualization in the web browser Opera 12.02 under Windows 8
    Mouse gestures: Some programs, such as the Opera web browser, implement so-called " mouse gestures " to trigger certain actions. This is basically an extension of dragging, with the mouse while holding the mouse button down, a certain, predefined figure is drawn on the screen, which is visually linked to the desired action. For example, a line is drawn to the left to tell the web browser to go back one page. However, there are currently only a few programs that support mouse gestures.

Depending on the program and the status in the program, a mouse action can have different effects: a click can move the insertion point in a text, open a menu or trigger a program function when a button is clicked. A double click can start a program or mark a word in a text.

Variations and alternatives to the mouse

Mouse with trackball (scrollball)
Two Apple mice: Magic Mouse (left) and Mighty Mouse (right)
Washable and moist disinfectable computer mouse for use in the medical field

For special applications and locations, variations of the standard mouse or alternative pointing devices have become established. Mice for applications in which a lot of cross-scrolling has to be done have an additional, horizontal scroll wheel, or even a small scroll ball. The mouse-related trackball can be used to avoid health problems that are typical of mice. The mouse ball used in the past is attached to the top instead of the underside and is moved with the fingers while the device itself remains in place. This makes it suitable for use in confined workplaces. Another alternative is the roller bar mouse (English: Barmouse ) lying in front of the keyboard .

On portable computers such as notebooks , touch-sensitive touchpads are usually built in, and higher-quality devices (mostly business computers) have additional trackpoints . Of course, the pointing comfort of a real mouse is greater, so that many users often connect an additional small notebook mouse.

Touchscreens are screens that, thanks to their sensitivity to touch, also serve as input devices and thus make a separate pointing device superfluous, including the keyboard if necessary. For computers in public areas such as information terminals and ATMs, touchscreens have been an alternative to built-in keyboards for years. In smartphones , small touch screens have been established recently (2010) and begin since the first mass-market use in the iPad in larger, PC-typical resolutions to enforce.

Graphic tablets are often used in professional graphic design .

A 3D mouse can be used for construction and robotics , which, in addition to movement in the plane, records another dimension of movement and rotations around the spatial axes.

In the games area, electronic steering wheels, joysticks and gamepads can be viewed as alternatives to a mouse.

In the case of physical limitations, multiple sensors can simulate the function of the mouse (pointing and clicking). In difficult cases, complex solutions are also possible through camera recordings of head and eye movements for computer operation, which then not only replace the mouse function.

A large number of alternatives to the conventional mouse are used in the industrial environment, since the requirements are determined by the application and the environment. Often dustproof or waterproof devices or sterilizable surfaces are required here.

The function of the mouse can largely be replaced by the use of the keyboard, although this is not always intuitive, but more productive when capturing large amounts of data than constantly switching between mouse and keyboard. Sometimes it is necessary to press several keys at the same time, for example Alt-Esc to call up a menu, or to press certain keys repeatedly to move on the screen, for example with tab from one screen symbol to the next jump. The so-called keyboard mouse should also be mentioned in this context, which moves the mouse pointer over the second assignment of the numeric keypad.

Before the mouse became popular, the user interfaces of programs (apart from pure command line control commands) were controlled with a variety of keyboard commands. Some programs had menus and drop-down menus that were opened and operated using the keyboard. For example, with the spreadsheet program Lotus 1-2-3, a bold line border was created at the top of an area with the following key sequence:

:turned on the drop-down menu, f keyboard shortcuts for format , lfor line , ffor bold . ofor the top , .around a corner of the area to be formatted to ver anchor , Pfeiltastein order to expand the area Enteraround the formatting complete

while using the mouse the following clicks were required:

First, the mark of being formatted area, click on the menu above range , then the field: Properties , click on the icon - button line , click on the icon line style , click on the icon line color , click on the Cancel icon, click the worksheet , to switch off the inverse highlighting and view the result.

With the keyboard, 8 keys were usually pressed with ten-finger blind typing without looking, with the mouse the same thing was done with 8 clicks, whereby the mouse pointer had to be moved over the screen. The advantage of the mouse lies in its extremely intuitive use as a pointing device : the buttons based on it made it possible to expand the character formatting options in text-based and graphic user programs without having to set up and memorize increasingly confusing and extensive drop-down menus.

Problems using a mouse

Health problems

As long as in the early days the mouse was often only used to activate windows and select checkboxes, its shape was largely irrelevant. However, this changed significantly with the advent of graphical user interfaces. Continuous use of a computer mouse, especially with poor posture, can trigger pain in the wrist ( tendonitis ) or carpal tunnel syndrome . Pain in fingers that have been stretched unnaturally for a long time can also occur, known as so-called "mouse fingers ". If the symptoms extend beyond the hand area to the elbow and into the shoulder, one speaks colloquially of a "mouse arm". These two forms of stress are collectively referred to as RSI ( Repetitive Strain Injury Syndrome - injury due to repeated stress). Illnesses developed at computer workstations can constitute an occupational disease .

The alternating use of different input devices such as mouse, trackball and roller bar mouse as well as the use of ergonomically designed keyboards and voice control can help prevent such complaints . As a remedy, more ergonomic shapes have also been developed for the mouse itself, in order to adapt it to the natural positions of the hand and movements of fingers, joints and arm that are as stress-free as possible. For example, the index finger or ball of the mouse is often made longer. Alternative shapes have also been developed, such as the vertical mouse, in which the buttons are arranged in a vertical plane, which requires a more relaxed arm position, as the arm does not have to be twisted to the side of the body. With such ergonomically designed mice it is of course necessary to use reversed versions for right and left-handers. The use of palm rests also promises relief by relieving the wrist, which does not have to be angled upward so much.

If optical radio mice are used appropriately in terms of time , radiation that is dangerous for humans cannot be detected.

Left handedness

Current, ergonomically shaped mice often have the problem that they were only designed for use by right-handers. Left-handed people usually cannot use such mice at all or only with extremely poor posture. Since there is no left-handed version of most ergonomically designed mice, many left-handed people learn to use their mouse with their right hand. This problem does not exist with the symmetrical yet ergonomically shaped mice. Depending on the operating system, it is often possible to swap the function of the right and left mouse button so that left-handed people can work left-handed with a normal mouse. Depending on the type of mouse query, e.g. B. in computer games, it is possible that the key swap stored in the operating system is bypassed and the left-handed user has to swap fingers again.

Noise development

With the typical design of the keys and the acoustic feedback of the actuation with the help of the cracking frog effect when the mouse is clicked, there may be disruptive noises for the environment (e.g. in the recording studio , living room). Some manufacturers therefore offer other key technologies.

Mouse accessories

Mouse pad

The mouse pad is arguably the most popular mouse accessory used by most computer users. It's often made of cloth or plastic and provides a flat surface over which the mouse can be moved. Ball mice, in particular, can often only be used in conjunction with mouse pads, since the mouse ball relies on the high friction of a mouse pad in order to turn without any problems.

Mouse pads are available with different surfaces, for example fabric, paper or plastic. These have different properties in terms of pollution. Some fabric surfaces have a cleaning effect on the mouse balls.

Meanwhile, the industry also offers special mouse pads for computer gamers, which are supposed to generate very little friction in order to enable precise movement. These then often consist of hard plastic, special plastic fibers or glass and are often only designed for the use of optical or laser mice. Optical and laser mice sometimes work poorly on reflective surfaces.

Ergonomic mouse pads have a special raised contact surface for the wrist and relieve the hand.


Skatez are thin strips of plastic film with a very low coefficient of friction, such as Teflon , that are stuck to the underside of the mouse. They are already standard on many models and are offered in stores for retrofitting as glidetape or speedtape . Skatez ensure that sliding and static friction are reduced and the mouse slides more easily over the surface.

Computer mice on workstations for visually scanning the surface for structured, glass or metal mouse pads are covered with replaceable, non-scratching felt strips on the underside to improve the gliding ability.

Cable holder

Cable holders should ensure that mouse cables do not get in the way when moving. If the (USB) mouse is not connected to the (USB) keyboard but directly to the computer, it should also be prevented that the weight of the cable down to the computer under the table creates additional tension on the cable.

Some cable holders are already integrated into the mouse pad, others have to be attached to the table, for example. A glued-on eyelet for the edge of the table is common, at which the mouse cable length that remains freely available on the table is determined by firmly clamping it. A solid textile adhesive tape has proven to be the simplest form of cable holder. The Mouse Bungee is a further development . With it, the cable length of the mouse can be optimally adapted to the swept area of ​​the mouse pad.

Palm rest

A palm rest is a small, padded pillow or pad . The filling can be made of gel ( silicone , neoprene ) or natural materials. It ensures that the wrist is not at work bends and mouse operation more from above what the strain on the hand and then the fatigue will decrease while working.

Manufacturer (selection)

Since mice are a very highly standardized product in terms of their structure, various computer manufacturers no longer make them themselves, but rather buy them in from specialized manufacturers. Well-known manufacturers of computer mice are:


  • Thierry Bardini: Bootstrapping: Douglas Engelbart , Coevolution, and the Origins of Personal Computing. Stanford University Press, Stanford, CA 2000, ISBN 0-8047-3871-8 (English).
  • Michael Friedewald : The computer as a tool and medium: the intellectual and technical roots of the personal computer (= Aachen contributions to the history of science and technology in the 20th century, volume 3). GNT Verlag for the History of Science and Technology, Berlin / Diepholz 1999, ISBN 3-928186-47-7 (Dissertation Technical University Aachen 1999, 497 pages with illustrations, 21 cm).
  • EN ISO 9241-9: 2000. Requirements for input devices - with the exception of keyboards.
  • Ernst Ahlers, Sven Schulz: USB peripherals for Windows computers. In: c't 15/1998. Heise Verlag, Hanover, p. 168 ff.
  • Klaus Dembowski : PC hardware reference: Information on all hardware in quick access. 10th edition. Markt & Technik Verlag, Munich 2000, ISBN 3-8272-5606-2 , pp. 472-480, 640-647.

Web links

Commons : Mice (computers)  - Collection of pictures, videos and audio files
Wiktionary: Computer mouse  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. With the 3D mouse , the movement information is three-dimensional.
  2. ^ I. Scott MacKenzie: Human-Computer Interaction: An Empirical Research Perspective . Newnes, December 31, 2012, ISBN 978-0-12-407165-0 , pp. 6-.
  3. Drawing from Engelbart's patent specification on , accessed on July 20, 2008 (English)
  4. On the trail of the German computer mouse . Retrieved November 8, 2011.
  5. Telefunken's "Trackball" . Retrieved November 8, 2011.
  6. Interview with Rainer Mallebrein. February 13, 2018, accessed January 10, 2019 .
  7. Brochure for the TR-440. May 2, 1966. Retrieved January 10, 2019 .
  8. ^ Gerhard Fischer: First experiences with LISA . 65xx MICRO MAG, No. 33, October 1983, archived with Computer History Online
  9. ZDNET introduces the first laser mouse
  10. Graphic: Working principle of the laser mouse in contrast to the normal optical mouse
  13. Germanwatch about the fair mouse ( Memento of the original from September 28, 2014 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot /
  14. Microsoft: BlueTrack technology (German)
  17. Klaus Dembowski: PC Hardware Reference: Information on all hardware in quick access . 10th edition. Markt & Technik, Munich 2000, ISBN 3-8272-5606-2 , p. 472–480 (chapter "Mouse") .
  18. Reference to the PS / 2 mouse protocol (English; PDF; 484 kB)
  19. Klaus Dembowski: PC Hardware Reference: Information on all hardware in quick access . 10th edition. Markt & Technik, Munich 2000, ISBN 3-8272-5606-2 , p. 640–646 (chapter "Universal Serial Bus") .
  20. LDP project: three-button mice under Linux (English)
  21. Documents on the USB bus (English)
  22. Stefan IJmker, Maaika A. Huysmans, Allard J van der Beek, Dirk L. Knol, Willem van Mechelen, Paulien M. Bongers, Birgitte M. Blatter: Software-recorded and self-reported duration of computer use in relation to the onset of severe arm-wrist-hand pain and neck-shoulder pain . In: Occupational and Environmental Medicine . tape 68 , no. 7 , 2011, p. 502–509 , doi : 10.1136 / oem.2010.056267 ( online [accessed July 13, 2014]). It was first published online in 2010. “On average, participants had a recorded computer duration of 12.5 (SD = 4.5) h per week, a mouse duration of 6.6 (SD = 3.1) h per week and a recorded keyboard duration of 3.1 (SD = 1.5 ) h per week. "
  23. Alina Brack: Rollermouse Red - computer mouse for a healthy posture. In: Swiss IT Magazine from January 2014. February 9, 2014, accessed on May 17, 2016 .
  24. Mouse without clicking-sound ( Memento from September 2, 2011 in the Internet Archive ) (English)
  25. ^ Rudolf Kellermann Prize for the History of Technology 1999
This version was added to the list of articles worth reading on August 9, 2006 .