Dysan was a storage media manufacturing corporation, formed in 1973 in San Jose, California, by CEO and former president C. Norman Dion of San Jose, California, it was instrumental in the development of the 5.25" floppy disk, which appeared in 1976. In 1983, Jerry Pournelle reported in BYTE that a software-publisher friend of his "distributes all his software on Dysan disks, it costs more to begin with, but saves in the long run, or so he says". By that year Dysan was a Fortune 500 company, had over 1200 employees, was ranked as among the top ten private sector employers within the Silicon Valley by the San Jose Mercury News, in terms of number of employees. In addition, some of Dysan's administrative and disk production facilities, located within the company's Santa Clara, manufacturing campus, were regarded as architecturally remarkable. For example, some of Dysan's Santa Clara campus magnetic media manufacturing facilities included architectural features such as large indoor employee lounge atriums, incorporating glass encased ceilings and walls, live indoor lush landscaping, running water creeks, ponds with live fish.
In addition to manufacturing floppies, tape drives and hard disks, Dysan produced hardware and storage containers for the disks. Dysan merged with Xidex Magnetics in the spring of 1984. In 1997, under the direction of Jerry Ticerelli, Xidex declared bankruptcy. Xidex was absorbed by Anacomp and spun off as a wholly owned subsidiary as Dysan. After a brief re-opening in 2003, the company closed six months under the direction of Dylan Campbell, it is possible that Dysan was one of the first tech-based companies to offer a service for recycling used products. Some Dysan packaging included the following label: Flexible media should be disposed of in an environmentally sound manner. Consumers may send used diskettes to: Dysan Enviro-Center P. O. Box 361510 Milpitas, CA 95036-1510
A touchscreen, or touch screen, is an input device and layered on the top of an electronic visual display of an information processing system. A user can give input or control the information processing system through simple or multi-touch gestures by touching the screen with a special stylus or one or more fingers; some touchscreens use ordinary or specially coated gloves to work while others may only work using a special stylus or pen. The user can use the touchscreen to react to what is displayed and, if the software allows, to control how it is displayed; the touchscreen enables the user to interact directly with what is displayed, rather than using a mouse, touchpad, or other such devices. Touchscreens are common in devices such as Nintendo game consoles, personal computers, electronic voting machines, point-of-sale systems, they can be attached to computers or, as terminals, to networks. They play a prominent role in the design of digital appliances such as personal digital assistants and some e-readers.
The popularity of smartphones and many types of information appliances is driving the demand and acceptance of common touchscreens for portable and functional electronics. Touchscreens are found in the medical field, heavy industry, automated teller machines, kiosks such as museum displays or room automation, where keyboard and mouse systems do not allow a suitably intuitive, rapid, or accurate interaction by the user with the display's content; the touchscreen sensor and its accompanying controller-based firmware have been made available by a wide array of after-market system integrators, not by display, chip, or motherboard manufacturers. Display manufacturers and chip manufacturers have acknowledged the trend toward acceptance of touchscreens as a user interface component and have begun to integrate touchscreens into the fundamental design of their products. Eric Johnson, of the Royal Radar Establishment, located in Malvern, described his work on capacitive touchscreens in a short article published in 1965 and more fully—with photographs and diagrams—in an article published in 1967.
The application of touch technology for air traffic control was described in an article published in 1968. Frank Beck and Bent Stumpe, engineers from CERN, developed a transparent touchscreen in the early 1970s, based on Stumpe's work at a television factory in the early 1960s. Manufactured by CERN, it was put to use in 1973. A resistive touchscreen was developed by American inventor George Samuel Hurst, who received US patent No. 3,911,215 on October 7, 1975. The first version was produced in 1982. In 1972, a group at the University of Illinois filed for a patent on an optical touchscreen that became a standard part of the Magnavox Plato IV Student Terminal and thousands were built for this purpose; these touchscreens had a crossed array of 16×16 infrared position sensors, each composed of an LED on one edge of the screen and a matched phototransistor on the other edge, all mounted in front of a monochrome plasma display panel. This arrangement could sense any fingertip-sized opaque object in close proximity to the screen.
A similar touchscreen was used on the HP-150 starting in 1983. The HP 150 was one of the world's earliest commercial touchscreen computers. HP mounted their infrared transmitters and receivers around the bezel of a 9-inch Sony cathode ray tube. In 1984, Fujitsu released a touch pad for the Micro 16 to accommodate the complexity of kanji characters, which were stored as tiled graphics. In 1985, Sega released the Terebi Oekaki known as the Sega Graphic Board, for the SG-1000 video game console and SC-3000 home computer, it consisted of a plastic pen and a plastic board with a transparent window where pen presses are detected. It was used with a drawing software application. A graphic touch tablet was released for the Sega AI computer in 1986. Touch-sensitive control-display units were evaluated for commercial aircraft flight decks in the early 1980s. Initial research showed that a touch interface would reduce pilot workload as the crew could select waypoints and actions, rather than be "head down" typing latitudes and waypoint codes on a keyboard.
An effective integration of this technology was aimed at helping flight crews maintain a high-level of situational awareness of all major aspects of the vehicle operations including the flight path, the functioning of various aircraft systems, moment-to-moment human interactions. In the early 1980s, General Motors tasked its Delco Electronics division with a project aimed at replacing an automobile's non-essential functions from mechanical or electro-mechanical systems with solid state alternatives wherever possible; the finished device was dubbed the ECC for "Electronic Control Center", a digital computer and software control system hardwired to various peripheral sensors, solenoids, antenna and a monochrome CRT touchscreen that functioned both as display and sole method of input. The ECC replaced the traditional mechanical stereo, fan and air conditioner controls and displays, was capable of providing detailed and specific information about the vehicle's cumulative and current operating status in real time.
The ECC was standard equipment on the 1985–1989 Buick Riviera and the 1988–1989 Buick Reatta, but was unpopular with consumers—partly due to the technophobia of some traditional Buick customers, but because of costly technical problems suffered by the ECC's touchscreen which would render climate control or stereo operation impo
An optical mouse is a computer mouse which uses a light source a light-emitting diode, a light detector, such as an array of photodiodes, to detect movement relative to a surface. Variations of the optical mouse have replaced the older mechanical mouse design, which uses moving parts to sense motion; the earliest optical mice detected movement on pre-printed mousepad surfaces. Modern optical mice work on most opaque diffusely reflective surfaces like paper, but most of them do not work properly on specularly reflective surfaces like polished stone or transparent surfaces like glass. Optical mice that use dark field illumination can function reliably on such surfaces. Though not referred to as optical mice, nearly all mechanical mice tracked movement using LEDs and photodiodes to detect when beams of infrared light did and didn't pass through holes in an incremental rotary encoder wheel. Thus, the primary distinction of “optical mice” is not their use of optics, but their complete lack of moving parts to track mouse movement, instead employing an solid-state system.
The first two optical mice, first demonstrated by two independent inventors in December 1980, had different basic designs: One of these, invented by Steve Kirsch of MIT and Mouse Systems Corporation, used an infrared LED and a four-quadrant infrared sensor to detect grid lines printed with infrared absorbing ink on a special metallic surface. Predictive algorithms in the CPU of the mouse calculated the direction over the grid; the other type, invented by Richard F. Lyon of Xerox, used a 16-pixel visible-light image sensor with integrated motion detection on the same chip and tracked the motion of light dots in a dark field of a printed paper or similar mouse pad; the Kirsch and Lyon mouse types had different behaviors, as the Kirsch mouse used an x-y coordinate system embedded in the pad, would not work when the pad was rotated, while the Lyon mouse used the x-y coordinate system of the mouse body, as mechanical mice do. The optical mouse sold with the Xerox STAR office computer used an inverted sensor chip packaging approach patented by Lisa M. Williams and Robert S. Cherry of the Xerox Microelectronics Center.
Modern surface-independent optical mice work by using an optoelectronic sensor to take successive images of the surface on which the mouse operates. As computing power grew cheaper, it became possible to embed more powerful special-purpose image-processing chips in the mouse itself; this advance enabled the mouse to detect relative motion on a wide variety of surfaces, translating the movement of the mouse into the movement of the cursor and eliminating the need for a special mouse-pad. A surface-independent coherent light optical mouse design was patented by Stephen B. Jackson at Xerox in 1988; the first commercially available, modern optical computer mice were the Microsoft IntelliMouse with IntelliEye and IntelliMouse Explorer, introduced in 1999 using technology developed by Hewlett-Packard. It worked on any surface, represented a welcome improvement over mechanical mice, which would pick up dirt, track capriciously, invite rough handling, need to be taken apart and cleaned frequently. Other manufacturers soon followed Microsoft’s lead using components manufactured by the HP spin-off Agilent Technologies, over the next several years mechanical mice became obsolete.
The technology underlying the modern optical computer mouse is known as digital image correlation, a technology pioneered by the defense industry for tracking military targets. A simple binary-image version of digital image correlation was used in the 1980 Lyon optical mouse. Optical mice use image sensors to image occurring texture in materials such as wood, mouse pads and Formica; these surfaces, when lit at a grazing angle by a light emitting diode, cast distinct shadows that resemble a hilly terrain lit at sunset. Images of these surfaces are captured in continuous succession and compared with each other to determine how far the mouse has moved. To understand how optical flow is used in optical mice, imagine two photographs of the same object except offset from each other. Place both photographs on a light table to make them transparent, slide one across the other until their images line up; the amount that the edges of one photograph overhang the other represents the offset between the images, in the case of an optical computer mouse the distance it has moved.
Optical mice capture more per second. Depending on how fast the mouse is moving, each image will be offset from the previous one by a fraction of a pixel or as many as several pixels. Optical mice mathematically process these images using cross correlation to calculate how much each successive image is offset from the previous one. An optical mouse might use an image sensor having an 18 × 18 pixel array of monochromatic pixels, its sensor would share the same ASIC as that used for storing and processing the images. One refinement would be accelerating the correlation process by using information from previous motions, another refinement would be preventing deadbands when moving by adding interpolation or frame-skipping; the development of the modern optical mouse at Hewlett-Packard Co. was supported by a succession of related projects during the 1990s at HP Laboratories. In 1992 William Holland was awarded US Patent 5,089,712 and John Ertel, William Holland, Kent Vincent, Rueiming Jamp, Richard Baldwin were awarded US Patent 5,149,980 for measuring linear paper advance in a printer by correlating images of paper fibers.
Ross R. Allen, David Beard, Mark T. Smith, Barclay J. Tullis were awarded US Patents 5,578,813 and 5,6
A game controller is a device used with games or entertainment systems to provide input to a video game to control an object or character in the game. Before the seventh generation of video game consoles, plugging in a controller into one of a console's controller ports were the primary means of using a game controller, although since they have been replaced by wireless controllers, which do not require controller ports on the console but are battery-powered. USB game controllers could be connected to a computer with a USB port. Input devices that have been classified as game controllers include keyboards, gamepads, etc. Special purpose devices, such as steering wheels for driving games and light guns for shooting games, are game controllers. Game controllers have been improved over the years to be as user friendly as possible; the Microsoft Xbox controller, with its shoulder triggers that mimic actual triggers such as those found on guns, has become popular for shooting games. Some controllers are designed to be best for one type of game, such as steering wheels for driving games, or dance pads for dancing games.
One of the first video game controllers was a simple dial and single button, used to control the game Tennis for Two. Controllers have since evolved to include directional pads, multiple buttons, analog sticks, motion detection, touch screens and a plethora of other features. A gamepad known as a joypad, is held in both hands with thumbs and fingers used to provide input. Gamepads can have a number of action buttons combined with one or more omnidirectional control sticks or buttons. Action buttons are handled with the digits on the right hand, the directional input handled with the left. Gamepads are the primary means of input on most modern video game consoles. Due to the ease of use and user-friendly nature of gamepads, they have spread from their origin on traditional consoles to computers, where a variety of games and emulators support their input as a replacement for keyboard and mouse input. Most modern game controllers are a variation of a standard gamepad. Common additions include shoulder buttons placed along the edges of the pad, centrally placed buttons labeled start and mode, an internal motor to provide haptic feedback.
As modern game controllers advance, so too do their user ability qualities. The controllers become smaller and more compact to more and comfortably, fit within the user's hand. Modern examples can be drawn from systems such as Xbox, whose controller has transformed subtly, yet from the original Xbox 360 controller to the Xbox One controller introduced in 2013. A paddle is a controller that features one or more fire buttons; the wheel is used to control movement of the player or of an object along one axis of the video screen. Paddle controllers were the first analog controllers and they lost popularity when "paddle and ball" type games fell out of favor. A variation, the Atari driving controller, appeared on the Atari 2600. Designed for the game Indy 500, it functioned identically in operation and design to the regular paddle controller; the exceptions were that its wheel could be continuously rotated in either direction, that it was missing the extra paddle included on the previous model. Unlike a spinner, friction prevented the wheel from gaining momentum.
A joystick is a peripheral that consists of a handheld stick that can be tilted around either of two axes and twisted around a third. The joystick is used for flight simulators. HOTAS controllers, composed of a joystick and throttle quadrant are a popular combination for flight simulation among its most fanatic devotees. Most joysticks are designed to be operated with the user's primary hand, with the base either held in the opposite hand or mounted on a desk. Arcade controllers are joysticks featuring a shaft that has a ball or drop-shaped handle, one or more buttons for in game actions; the layout has the joystick on the left, the buttons on the right, although there are instances when this is reversed. A trackball is an upside-down mouse, manipulated with the palm of one's hand, it has the advantage of not requiring a lot of desktop space, that it is as fast as one can roll the ball on it. This is faster, it was a precursor to the mouse. Notable uses of a Trackball as a gaming controller would be games such as Centipede, Marble Madness, Golden Tee Golf and SegaSonic the Hedgehog.
A throttle quadrant is a set of one or more levers that are most used to simulate throttles or other similar controls in a real vehicle an aircraft. Throttle quadrants are most popular in conjunction with joysticks or yokes used in flight simulation. A Racing wheel a larger version of a paddle, is used in most racing arcade games as well as more recent racing simulators such as Live for Speed, Grand Prix Legends, GTR2, Richard Burns Rally. While most arcade racing games have been using steering wheels since Gran Trak 10 in 1974, the first steering wheels for home systems appeared on fifth-generation consoles such as the PlayStation and Nintendo 64. Many are force feedback, designed to give the same feedback as would be experienced when driving a real car, but the realism of this depends on the game, they come with pedals to control the gas and brake. Shifting is taken care of in various ways including paddle shifting systems, simple stick shifters which are moved forward or back to change gears or more complex shifters which mimic those of real ve
A microphone, colloquially nicknamed mic or mike, is a transducer that converts sound into an electrical signal. Microphones are used in many applications such as telephones, hearing aids, public address systems for concert halls and public events, motion picture production and recorded audio engineering, sound recording, two-way radios, megaphones and television broadcasting, in computers for recording voice, speech recognition, VoIP, for non-acoustic purposes such as ultrasonic sensors or knock sensors. Several different types of microphone are in use, which employ different methods to convert the air pressure variations of a sound wave to an electrical signal; the most common are the dynamic microphone. Microphones need to be connected to a preamplifier before the signal can be recorded or reproduced. In order to speak to larger groups of people, a need arose to increase the volume of the human voice; the earliest devices used to achieve this were acoustic megaphones. Some of the first examples, from fifth century BC Greece, were theater masks with horn-shaped mouth openings that acoustically amplified the voice of actors in amphitheatres.
In 1665, the English physicist Robert Hooke was the first to experiment with a medium other than air with the invention of the "lovers' telephone" made of stretched wire with a cup attached at each end. In 1861, German inventor Johann Philipp Reis built an early sound transmitter that used a metallic strip attached to a vibrating membrane that would produce intermittent current. Better results were achieved in 1876 with the "liquid transmitter" design in early telephones from Alexander Graham Bell and Elisha Gray – the diaphragm was attached to a conductive rod in an acid solution; these systems, gave a poor sound quality. The first microphone that enabled proper voice telephony was the carbon microphone; this was independently developed by David Edward Hughes in England and Emile Berliner and Thomas Edison in the US. Although Edison was awarded the first patent in mid-1877, Hughes had demonstrated his working device in front of many witnesses some years earlier, most historians credit him with its invention.
The carbon microphone is the direct prototype of today's microphones and was critical in the development of telephony and the recording industries. Thomas Edison refined the carbon microphone into his carbon-button transmitter of 1886; this microphone was employed at the first radio broadcast, a performance at the New York Metropolitan Opera House in 1910. In 1916, E. C. Wente of Western Electric developed the next breakthrough with the first condenser microphone. In 1923, the first practical moving coil microphone was built; the Marconi-Sykes magnetophone, developed by Captain H. J. Round, became the standard for BBC studios in London; this was improved in 1930 by Alan Blumlein and Herbert Holman who released the HB1A and was the best standard of the day. In 1923, the ribbon microphone was introduced, another electromagnetic type, believed to have been developed by Harry F. Olson, who reverse-engineered a ribbon speaker. Over the years these microphones were developed by several companies, most notably RCA that made large advancements in pattern control, to give the microphone directionality.
With television and film technology booming there was demand for high fidelity microphones and greater directionality. Electro-Voice responded with their Academy Award-winning shotgun microphone in 1963. During the second half of 20th century development advanced with the Shure Brothers bringing out the SM58 and SM57; the latest research developments include the use of fibre optics and interferometers. The sensitive transducer element of a microphone is called its capsule. Sound is first converted to mechanical motion by means of a diaphragm, the motion of, converted to an electrical signal. A complete microphone includes a housing, some means of bringing the signal from the element to other equipment, an electronic circuit to adapt the output of the capsule to the equipment being driven. A wireless microphone contains a radio transmitter. Microphones are categorized by their transducer principle, such as condenser, etc. and by their directional characteristics. Sometimes other characteristics such as diaphragm size, intended use or orientation of the principal sound input to the principal axis of the microphone are used to describe the microphone.
The condenser microphone, invented at Western Electric in 1916 by E. C. Wente, is called a capacitor microphone or electrostatic microphone—capacitors were called condensers. Here, the diaphragm acts as one plate of a capacitor, the vibrations produce changes in the distance between the plates. There are two types, depending on the method of extracting the audio signal from the transducer: DC-biased microphones, radio frequency or high frequency condenser microphones. With a DC-biased microphone, the plates are biased with a fixed charge; the voltage maintained across the capacitor plates changes with the vibrations in the air, according to the capacitance equation, where Q = charge in coulombs, C = capacitance in farads and V = potential difference in volts. The capacitance of the plates is inversely proportional to the distance between them for a parallel-plate capacitor; the assembly of fixed and movable plates is called an "element" or "capsule". A nearly constant charge is maintained on the capa
Disk read-and-write head
Disk read/write heads are the small parts of a disk drive which move above the disk platter and transform the platter's magnetic field into electrical current or, vice versa, transform electrical current into magnetic field. The heads have gone through a number of changes over the years. In a hard drive, the heads'fly' above the disk surface with clearance of as little as 3 nanometres; the "flying height" is decreasing to enable higher areal density. The flying height of the head is controlled by the design of an air-bearing etched onto the disk-facing surface of the slider; the role of the air bearing is to maintain the flying height constant as the head moves over the surface of the disk. If the head hits the disk's surface, a catastrophic head crash can result; the heads themselves started out similar to the heads in tape recorders—simple devices made out of a tiny C-shaped piece of magnetizable material called ferrite wrapped in a fine wire coil. When writing, the coil is energized, a strong magnetic field forms in the gap of the C, the recording surface adjacent to the gap is magnetized.
When reading, the magnetized material rotates past the heads, the ferrite core concentrates the field, a current is generated in the coil. In the gap the field is strong and quite narrow; that gap is equal to the thickness of the magnetic media on the recording surface. The gap determines the minimum size of a recorded area on the disk. Ferrite heads are large, write large features, they must be flown far from the surface thus requiring stronger fields and larger heads. Metal in Gap heads are ferrite heads with a small piece of metal in the head gap that concentrates the field; this allows smaller features to be written. MIG heads were replaced with thin film heads. Thin film heads were electronically similar to ferrite heads and used the same physics, but they were manufactured using photolithographic processes and thin films of material that allowed fine features to be created. Thin film heads were much smaller than MIG heads and therefore allowed smaller recorded features to be used. Thin film heads allowed 3.5 inch drives to reach 4GB storage capacities in 1995.
The geometry of the head gap was a compromise between what worked best for reading and what worked best for writing. The next head improvement was to optimize the thin film head for writing and to create a separate head for reading; the separate read head uses the magnetoresistive effect which changes the resistance of a material in the presence of magnetic field. These MR heads are able to read small magnetic features reliably, but can not be used to create the strong field used for writing; the term AMR is used to distinguish it from the introduced improvement in MR technology called GMR and "TMR". The introduction of the AMR head in 1990 by IBM led to a period of rapid areal density increases of about 100% per year. In 1997 GMR, giant magnetoresistive heads started to replace AMR heads. Since 1990s, a number of studies have been done on the effects of colossal magnetoresistance, which may allow for greater increases in density, but so far it has not led to practical applications because it requires low temperatures and large equipment size.
In 2004, the first drives to use tunneling MR heads were introduced by Seagate allowing 400 GB drives with 3 disk platters. Seagate introduced TMR heads featuring integrated microscopic heater coils to control the shape of the transducer region of the head during operation; the heater can be activated prior to the start of a write operation to ensure proximity of the write pole to the disk/medium. This improves the written magnetic transitions by ensuring that the head's write field saturates the magnetic disk medium; the same thermal actuation approach can be used to temporarily decrease the separation between the disk medium and the read sensor during the readback process, thus improving signal strength and resolution. By mid-2006 other manufacturers have begun to use similar approaches in their products. During the same time frame a transition to perpendicular magnetic recording is occurring, in which for reasons of improved stability and higher areal density potential, the traditional in-plane orientation of magnetization in the disk is being changed to a perpendicular orientation.
This has major implications for the write process and the write head structure, as well as for the design of the magnetic disk media or hard disk platter, less directly so for the read sensor of the magnetic head. Head crash The PC Guide: Function of the Read/Write Heads IBM Research: GMR introduction, animations Hitachi Global Storage Technologies: Recording Head Materials
A webcam is a video camera that feeds or streams its image in real time to or through a computer to a computer network. When "captured" by the computer, the video stream may be saved, viewed or sent on to other networks travelling through systems such as the internet, e-mailed as an attachment; when sent to a remote location, the video stream may be viewed or on sent there. Unlike an IP camera, a webcam is connected by a USB cable, or similar cable, or built into computer hardware, such as laptops; the term "webcam" may be used in its original sense of a video camera connected to the Web continuously for an indefinite time, rather than for a particular session supplying a view for anyone who visits its web page over the Internet. Some of them, for example, those used as online traffic cameras, are expensive, rugged professional video cameras. Webcams are known for their low manufacturing cost and their high flexibility, making them the lowest-cost form of videotelephony. Despite the low cost, the resolution offered at present is rather impressive, with low-end webcams offering resolutions of 320×240, medium webcams offering 640×480 resolution, high-end webcams offering 1280×720 or 1920×1080 resolution.
They have become a source of security and privacy issues, as some built-in webcams can be remotely activated by spyware. The most popular use of webcams is the establishment of video links, permitting computers to act as videophones or videoconference stations. Other popular uses include security surveillance, computer vision, video broadcasting, for recording social videos; the video streams provided by webcams can be used for a number of purposes, each using appropriate software: Most modern webcams are capable of capturing arterial pulse rate by the use of a simple algorithmic trick. Researchers claim. Webcams may be installed at places such as childcare centres, offices and private areas to monitor security and general activity. Webcams have been used for augmented reality experiences online. One such function has the webcam act as a "magic mirror" to allow an online shopper to view a virtual item on themselves; the Webcam Social Shopper is one example of software. Webcam can be added to instant messaging, text chat services such as AOL Instant Messenger, VoIP services such as Skype, one-to-one live video communication over the Internet has now reached millions of mainstream PC users worldwide.
Improved video quality has helped webcams encroach on traditional video conferencing systems. New features such as automatic lighting controls, real-time enhancements, automatic face tracking and autofocus, assist users by providing substantial ease-of-use, further increasing the popularity of webcams. Webcam features and performance can vary by program, computer operating system, by the computer's processor capabilities. Video calling support has been added to several popular instant messaging programs. Webcams can be used as security cameras. Software is available to allow PC-connected cameras to watch for movement and sound, recording both when they are detected; these recordings can be saved to the computer, e-mailed, or uploaded to the Internet. In one well-publicised case, a computer e-mailed images of the burglar during the theft of the computer, enabling the owner to give police a clear picture of the burglar's face after the computer had been stolen. Unauthorized access of webcams can present significant privacy issues.
In December 2011, Russia announced that 290,000 Webcams would be installed in 90,000 polling stations to monitor the Russian presidential election, 2012. Webcams can be used to take video clips and still pictures. Various software tools in wide use can be employed for this, such as PicMaster, Photo Booth, or Cheese. For a more complete list see Comparison of webcam software. Special software can use the video stream from a webcam to assist or enhance a user's control of applications and games. Video features, including faces, shapes and colors can be observed and tracked to produce a corresponding form of control. For example, the position of a single light source can be tracked and used to emulate a mouse pointer, a head-mounted light would enable hands-free computing and would improve computer accessibility; this can be applied to games, providing additional control, improved interactivity and immersiveness. FreeTrack is a free webcam motion-tracking application for Microsoft Windows that can track a special head-mounted model in up to six degrees of freedom and output data to mouse, keyboard and FreeTrack-supported games.
By removing the IR filter of the webcam, IR LEDs can be used, which has the advantage of being invisible to the naked eye, removing a distraction from the user. TrackIR is a commercial version of this technology; the EyeToy for the PlayStation 2, PlayStation Eye for the PlayStation 3, the Xbox Live Vision camera and Kinect motion sensor for the Xbox 360 and are color digital cameras that have been used as control input devices by some games. Small webcam-based PC games are available as either standalone executables or inside web browser windows using Adobe Flash. With very-low-light capability, a few specific models of webcams are popular to photograph the night sky by astronomers and astro photographers; these are manual-focus cameras and contain an old CCD array instead of comparatively newer CMOS array. The lenses of the cameras are removed and these are attached to telescopes to record images