International Business Machines Corporation is an American multinational information technology company headquartered in Armonk, New York, with operations in over 170 countries. The company began in 1911, founded in Endicott, New York, as the Computing-Tabulating-Recording Company and was renamed "International Business Machines" in 1924. IBM produces and sells computer hardware and software, provides hosting and consulting services in areas ranging from mainframe computers to nanotechnology. IBM is a major research organization, holding the record for most U. S. patents generated by a business for 26 consecutive years. Inventions by IBM include the automated teller machine, the floppy disk, the hard disk drive, the magnetic stripe card, the relational database, the SQL programming language, the UPC barcode, dynamic random-access memory; the IBM mainframe, exemplified by the System/360, was the dominant computing platform during the 1960s and 1970s. IBM has continually shifted business operations by focusing on higher-value, more profitable markets.
This includes spinning off printer manufacturer Lexmark in 1991 and the sale of personal computer and x86-based server businesses to Lenovo, acquiring companies such as PwC Consulting, SPSS, The Weather Company, Red Hat. In 2014, IBM announced that it would go "fabless", continuing to design semiconductors, but offloading manufacturing to GlobalFoundries. Nicknamed Big Blue, IBM is one of 30 companies included in the Dow Jones Industrial Average and one of the world's largest employers, with over 380,000 employees, known as "IBMers". At least 70% of IBMers are based outside the United States, the country with the largest number of IBMers is India. IBM employees have been awarded five Nobel Prizes, six Turing Awards, ten National Medals of Technology and five National Medals of Science. In the 1880s, technologies emerged that would form the core of International Business Machines. Julius E. Pitrap patented the computing scale in 1885. On June 16, 1911, their four companies were amalgamated in New York State by Charles Ranlett Flint forming a fifth company, the Computing-Tabulating-Recording Company based in Endicott, New York.
The five companies had offices and plants in Endicott and Binghamton, New York. C.. They manufactured machinery for sale and lease, ranging from commercial scales and industrial time recorders and cheese slicers, to tabulators and punched cards. Thomas J. Watson, Sr. fired from the National Cash Register Company by John Henry Patterson, called on Flint and, in 1914, was offered a position at CTR. Watson joined CTR as General Manager 11 months was made President when court cases relating to his time at NCR were resolved. Having learned Patterson's pioneering business practices, Watson proceeded to put the stamp of NCR onto CTR's companies, he implemented sales conventions, "generous sales incentives, a focus on customer service, an insistence on well-groomed, dark-suited salesmen and had an evangelical fervor for instilling company pride and loyalty in every worker". His favorite slogan, "THINK", became a mantra for each company's employees. During Watson's first four years, revenues reached $9 million and the company's operations expanded to Europe, South America and Australia.
Watson never liked the clumsy hyphenated name "Computing-Tabulating-Recording Company" and on February 14, 1924 chose to replace it with the more expansive title "International Business Machines". By 1933 most of the subsidiaries had been merged into one company, IBM. In 1937, IBM's tabulating equipment enabled organizations to process unprecedented amounts of data, its clients including the U. S. Government, during its first effort to maintain the employment records for 26 million people pursuant to the Social Security Act, the tracking of persecuted groups by Hitler's Third Reich through the German subsidiary Dehomag. In 1949, Thomas Watson, Sr. created IBM World Trade Corporation, a subsidiary of IBM focused on foreign operations. In 1952, he stepped down after 40 years at the company helm, his son Thomas Watson, Jr. was named president. In 1956, the company demonstrated the first practical example of artificial intelligence when Arthur L. Samuel of IBM's Poughkeepsie, New York, laboratory programmed an IBM 704 not to play checkers but "learn" from its own experience.
In 1957, the FORTRAN scientific programming language was developed. In 1961, IBM developed the SABRE reservation system for American Airlines and introduced the successful Selectric typewriter. In 1963, IBM employees and computers helped. A year it moved its corporate headquarters from New York City to Armonk, New York; the latter half of the 1960s saw IBM continue its support of space exploration, participating in the 1965 Gemini flights, 1966 Saturn flights and 1969 lunar mission. On April 7, 1964, IBM announced the first computer system family, the IBM System/360, it spanned the complete range of commercial and scientific applications from large to small, allowing companies for the first time to upgrade to models with greater computing capability without having to rewrite their applications. It was followed by the IBM System/370 in 1970. Together the
Coaxial cable, or coax is a type of electrical cable that has an inner conductor surrounded by a tubular insulating layer, surrounded by a tubular conducting shield. Many coaxial cables have an insulating outer sheath or jacket; the term coaxial comes from the outer shield sharing a geometric axis. Coaxial cable was invented by English engineer and mathematician Oliver Heaviside, who patented the design in 1880. Coaxial cable is a type of transmission line, used to carry high frequency electrical signals with low losses, it is used in such applications as telephone trunklines, broadband internet networking cables, high speed computer data busses, carrying cable television signals, connecting radio transmitters and receivers to their antennas. It differs from other shielded cables because the dimensions of the cable and connectors are controlled to give a precise, constant conductor spacing, needed for it to function efficiently as a transmission line. Coaxial cable is used as a transmission line for radio frequency signals.
Its applications include feedlines connecting radio transmitters and receivers to their antennas, computer network connections, digital audio, distribution of cable television signals. One advantage of coaxial over other types of radio transmission line is that in an ideal coaxial cable the electromagnetic field carrying the signal exists only in the space between the inner and outer conductors; this allows coaxial cable runs to be installed next to metal objects such as gutters without the power losses that occur in other types of transmission lines. Coaxial cable provides protection of the signal from external electromagnetic interference. Coaxial cable conducts electrical signal using an inner conductor surrounded by an insulating layer and all enclosed by a shield one to four layers of woven metallic braid and metallic tape; the cable is protected by an outer insulating jacket. The shield is kept at ground potential and a signal carrying voltage is applied to the center conductor; the advantage of coaxial design is that electric and magnetic fields are restricted to the dielectric with little leakage outside the shield.
Conversely and magnetic fields outside the cable are kept from interfering with signals inside the cable. Larger diameter cables and cables with multiple shields have less leakage; this property makes coaxial cable a good choice for carrying weak signals that cannot tolerate interference from the environment or for stronger electrical signals that must not be allowed to radiate or couple into adjacent structures or circuits. Common applications of coaxial cable include video and CATV distribution, RF and microwave transmission, computer and instrumentation data connections; the characteristic impedance of the cable is determined by the dielectric constant of the inner insulator and the radii of the inner and outer conductors. In radio frequency systems, where the cable length is comparable to the wavelength of the signals transmitted, a uniform cable characteristic impedance is important to minimize loss; the source and load impedances are chosen to match the impedance of the cable to ensure maximum power transfer and minimum standing wave ratio.
Other important properties of coaxial cable include attenuation as a function of frequency, voltage handling capability, shield quality. Coaxial cable design choices affect physical size, frequency performance, power handling capabilities, flexibility and cost; the inner conductor might be stranded. To get better high-frequency performance, the inner conductor may be silver-plated. Copper-plated steel wire is used as an inner conductor for cable used in the cable TV industry; the insulator surrounding the inner conductor may be solid plastic, a foam plastic, or air with spacers supporting the inner wire. The properties of the dielectric insulator determine some of the electrical properties of the cable. A common choice is a solid polyethylene insulator, used in lower-loss cables. Solid Teflon is used as an insulator; some coaxial lines have spacers to keep the inner conductor from touching the shield. Many conventional coaxial cables use braided copper wire forming the shield; this allows the cable to be flexible, but it means there are gaps in the shield layer, the inner dimension of the shield varies because the braid cannot be flat.
Sometimes the braid is silver-plated. For better shield performance, some cables have a double-layer shield; the shield might be just two braids, but it is more common now to have a thin foil shield covered by a wire braid. Some cables may invest in more than two shield layers, such as "quad-shield", which uses four alternating layers of foil and braid. Other shield designs sacrifice flexibility for better performance; those cables cannot be bent as the shield will kink, causing losses in the cable. When a foil shield is used a small wire conductor incorporated into the foil makes soldering the shield termination easier. For high-power radio-frequency transmission up to about 1 GHz, coaxial cable with a solid copper outer conductor is available in sizes of 0.25 inch upward. The outer conductor is corrugated like a bellows to permit flexibility and the inner conductor is held in position by a plastic spiral to approximate an air dielectric. One brand name for such cable is Heliax. Coaxial cables require an internal structure of an insulating material to maintain the spacing between the center conductor and shield.
A video card is an expansion card which generates a feed of output images to a display device. These are advertised as discrete or dedicated graphics cards, emphasizing the distinction between these and integrated graphics. At the core of both is the graphics processing unit, the main part that does the actual computations, but should not be confused as the video card as a whole, although "GPU" is used to refer to video cards. Most video cards are not limited to simple display output, their integrated graphics processor can perform additional processing, removing this task from the central processor of the computer. For example, Nvidia and AMD produced cards render the graphics pipeline OpenGL and DirectX on the hardware level. In the 2010s, there has been a tendency to use the computing capabilities of the graphics processor to solve non-graphic tasks; the graphics card is made in the form of a printed circuit board and inserted into an expansion slot, universal or specialized. Some have been made using dedicated enclosures, which are connected to the computer via a docking station or a cable.
Standards such as MDA, CGA, HGC, Tandy, PGC, EGA, VGA, MCGA, 8514 or XGA were introduced from 1982 to 1990 and supported by a variety of hardware manufacturers. 3dfx Interactive was one of the first companies to develop a GPU with 3D acceleration and the first to develop a graphical chipset dedicated to 3D, but without 2D support. Now the majority of modern video cards are built with either AMD-sourced or Nvidia-sourced graphics chips; until 2000, 3dfx Interactive was an important, groundbreaking, manufacturer. Most video cards offer various functions such as accelerated rendering of 3D scenes and 2D graphics, MPEG-2/MPEG-4 decoding, TV output, or the ability to connect multiple monitors. Video cards have sound card capabilities to output sound – along with the video for connected TVs or monitors with integrated speakers. Within the industry, video cards are sometimes called graphics add-in-boards, abbreviated as AIBs, with the word "graphics" omitted; as an alternative to the use of a video card, video hardware can be integrated into the motherboard, CPU, or a system-on-chip.
Both approaches can be called integrated graphics. Motherboard-based implementations are sometimes called "on-board video". All desktop computer motherboards with integrated graphics allow the disabling of the integrated graphics chip in BIOS, have a PCI, or PCI Express slot for adding a higher-performance graphics card in place of the integrated graphics; the ability to disable the integrated graphics sometimes allows the continued use of a motherboard on which the on-board video has failed. Sometimes both the integrated graphics and a dedicated graphics card can be used to feed separate displays; the main advantages of integrated graphics include cost, compactness and low energy consumption. The performance disadvantage of integrated graphics arises because the graphics processor shares system resources with the CPU. A dedicated graphics card has its own random access memory, its own cooling system, dedicated power regulators, with all components designed for processing video images. Upgrading to a dedicated graphics card offloads work from the CPU and system RAM, so not only will graphics processing be faster, but the computer's overall performance may improve.
Both AMD and Intel have introduced CPUs and motherboard chipsets which support the integration of a GPU into the same die as the CPU. AMD markets CPUs with integrated graphics under the trademark Accelerated Processing Unit, while Intel markets similar technology under the "Intel HD Graphics and Iris" brands. With the 8th Generation Processors, Intel announced the Intel UHD series of Integrated Graphics for better support of 4K Displays. Although they are still not equivalent to the performance of discrete solutions, Intel's HD Graphics platform provides performance approaching discrete mid-range graphics, AMD APU technology has been adopted by both the PlayStation 4 and Xbox One video game consoles; as the processing power of video cards has increased, so has their demand for electrical power. Current high-performance video cards tend to consume a great deal of power. For example, the thermal design power for the GeForce GTX TITAN is 250 watts; when tested while gaming, the GeForce GTX 1080 Ti Founder's Edition averaged 227 watts of power consumption.
While CPU and power supply makers have moved toward higher efficiency, power demands of GPUs have continued to rise, so video cards may have the largest power consumption in a computer. Although power supplies are increasing their power too, the bottleneck is due to the PCI-Express connection, limited to supplying 75 watts. Modern video cards with a power consumption of over 75 watts include a combination of six-pin or eight-pin sockets that connect directly to the power supply. Providing adequate cooling becomes a challenge in such computers. Computers with multiple video cards may need power supplies in the 1000–1500 W range. Heat extraction becomes a major design consideration for computers with two or more high-end video cards. Video cards for desktop computers come in one of two size profiles, which can allow a graphics card to be added to small-sized PCs; some video cards are not of usual size, are thus categorized as being low profile. Video card profiles are based on height only, with low-profile cards taking up less than the height of a
Generation loss is the loss of quality between subsequent copies or transcodes of data. Anything that reduces the quality of the representation when copying, would cause further reduction in quality on making a copy of the copy, can be considered a form of generation loss. File size increases are a common result of generation loss, as the introduction of artifacts may increase the entropy of the data through each generation. In analog systems, generation loss is due to noise and bandwidth issues in cables, mixers, recording equipment and anything else between the source and the destination. Poorly adjusted distribution amplifiers and mismatched impedances can make these problems worse. Repeated conversion between analog and digital can cause loss. Generation loss was a major consideration in complex analog audio and video editing, where multi-layered edits were created by making intermediate mixes which were "bounced down" back onto tape. Careful planning was required to minimize generation loss, the resulting noise and poor frequency response.
One way of minimizing the number of generations needed was to use an audio mixing or video editing suite capable of mixing a large number of channels at once. The introduction of professional analog noise reduction systems such as Dolby A helped reduce the amount of audible generation loss, but were superseded by digital systems which vastly reduced generation loss. According to ATIS, "Generation loss is limited to analog recording because digital recording and reproduction may be performed in a manner, free from generation loss." Used digital technology can eliminate generation loss. Copying a digital file gives an exact copy; this trait of digital technology has given rise to awareness of the risk of unauthorized copying. Before digital technology was widespread, a record label, for example, could be confident knowing that unauthorized copies of their music tracks were never as good as the originals. Processing a lossily compressed file rather than an original results in more loss of quality than generating the same output from an uncompressed original.
For example, a low-resolution digital image for a web page is better if generated from an uncompressed raw image than from an already-compressed JPEG file of higher quality. In digital systems, several techniques, used because of other advantages, may introduce generation loss and must be used with caution. However, copying a digital file itself incurs no generation loss--the copied file is identical to the original, provided a perfect copying channel is used; some digital transforms are reversible. Lossless compression is, by definition reversible, while lossy compression throws away some data which cannot be restored. Many DSP processes are not reversible, thus careful planning of an audio or video signal chain from beginning to end and rearranging to minimize multiple conversions is important to avoid generation loss. Arbitrary choices of numbers of pixels and sampling rates for source and intermediates can degrade digital signals in spite of the potential of digital technology for eliminating generation loss completely.
When using lossy compression, it will ideally only be done once, at the end of the workflow involving the file, after all required changes have been made. Converting between lossy formats – be it decoding and re-encoding to the same format, between different formats, or between different bitrates or parameters of the same format – causes generation loss. Repeated applications of lossy compression and decompression can cause generation loss if the parameters used are not consistent across generations. Ideally an algorithm will be both idempotent, meaning that if the signal is decoded and re-encoded with identical settings, there is no loss, scalable, meaning that if it is re-encoded with lower quality settings, the result will be the same as if it had been encoded from the original signal – see Scalable Video Coding. More transcoding between different parameters of a particular encoding will ideally yield the greatest common shared quality – for instance, converting from an image with 4 bits of red and 8 bits of green to one with 8 bits of red and 4 bits of green would ideally yield an image with 4 bits of red color depth and 4 bits of green color depth without further degradation.
Some lossy compression algorithms are much worse than others in this regard, being neither idempotent nor scalable, introducing further degradation if parameters are changed. For example, with JPEG, changing the quality setting will cause different quantization constants to be used, causing additional loss. Further, as JPEG is divided into 16×16 blocks, cropping that does not fall on an 8×8 boundary shifts the encoding blocks, causing substantial degradation – similar problems happen on rotation; this can be avoided by the use of similar tools for cropping. Similar degradation occurs. Digital resampling such as image scaling, other DSP techniques can introduce artifacts or degrade signal-to-noise ratio each time they are used if the underlying storage is lossless. Resampling causes aliasing, both blurring low-frequency components and adding high-frequency noise, causing jaggies, while rou
Mini-VGA connectors are a non-standard, proprietary alternative used on some laptops and other systems in place of the standard VGA connector, although most laptops use a standard VGA connector. Apple, HP and Asus have separate implementations using the same name. Apart from its compact form, mini-VGA ports have the added ability to output both composite and S-Video in addition to VGA signals through the use of EDID; the mini-DVI and now Mini DisplayPort connectors have replaced mini-VGA. Mini-VGA connectors are most seen on Apple's iBooks, eMacs, early PowerBooks, some iMacs, but has been included on several laptops manufactured by Sony. HP's versions are found in HP TouchSmarts; the mini-VGA connector can be used for video output. In this mode, S-Video chrominance and luminance signals replace the red and green channels, while an equivalent composite video signal is output on the blue channel; the horizontal and vertical sync pins are unused. Samsung Chromebooks, available since June 2011, feature their own implementation of Mini-VGA ports.
Various other Samsung laptops, such as the Series 7 and Series 9 versions feature this new connector. IBook Developer Note: External Display Port
In television, a ghost is a replica of the transmitted image, offset in position, super-imposed on top of the main image. It is caused when a TV signal travels by two different paths to a receiving antenna, with a slight difference in timing. Common causes of ghosts are: Mismatched impedance along the communication channel, which causes unwanted reflections; the technical term for this phenomenon is ringing. Multipath distortion, because radio frequency waves may take paths of different length to reach the receiver. In addition, RF leaks may allow a signal to enter the set by a different path. By getting a better antenna or cable system it can be mitigated. Note that ghosts are a problem specific to the video portion of television because it uses AM for transmission. SECAM TV uses FM for the chrominance signal, hence ghosting only affects the luma portion of its signal. TV is broadcast on VHF and UHF, which have line-of-sight propagation, reflect off of buildings and other objects; the audio portion uses FM, which has the desirable property that a stronger signal tends to overpower interference from weaker signals due to the capture effect.
When ghosts are bad in the picture, there may be little audio interference. If the ghost is seen on the left of the main picture it is that the problem is pre-echo, seen in buildings with long TV downleads where an RF leakage has allowed the TV signal to enter the tuner by a second route. For instance, plugging in an additional aerial to a TV which has a communal TV aerial connection can cause this condition. Ghosting is not specific to analog transmission, it may appear in digital television when interlaced video is incorrectly deinterlaced for display on progressive-scan output devices. The mechanisms that cause ghosting in analog television may corrupt the signal beyond use for digital television. 8VSB, COFDM, other modulation schemes seek to correct this. Ghost-canceling reference Onion skinning www1.electusdistribution.com.au/images_uploaded/tvrecepe.pdf www.ofcom.org.uk/static/archive/ra/publication/ra_info/ra323/ra323.htm#15
Digital Visual Interface
Digital Visual Interface is a video display interface developed by the Digital Display Working Group. The digital interface is used to connect a video source, such as a video display controller, to a display device, such as a computer monitor, it was developed with the intention of creating an industry standard for the transfer of digital video content. This interface is designed to transmit uncompressed digital video and can be configured to support multiple modes such as DVI-A, DVI-D or DVI-I. Featuring support for analog connections, the DVI specification is compatible with the VGA interface; this compatibility, along with other advantages, led to its widespread acceptance over competing digital display standards Plug and Display and Digital Flat Panel. Although DVI is predominantly associated with computers, it is sometimes used in other consumer electronics such as television sets and DVD players. DVI's digital video transmission format is based on panelLink, a serial format developed by Silicon Image that utilizes a high-speed serial link called transition minimized differential signaling.
Like modern analog VGA connectors, the DVI connector includes pins for the display data channel. A newer version of DDC called DDC2 allows the graphics adapter to read the monitor's extended display identification data. If a display supports both analog and digital signals in one DVI-I input, each input method can host a distinct EDID. Since the DDC can only support one EDID, this can be a problem if both the digital and analog inputs in the DVI-I port detect activity, it is up to the display to choose. When a source and display are connected, the source first queries the display's capabilities by reading the monitor EDID block over an I²C link; the EDID block contains the display's identification, color characteristics, table of supported video modes. The table can designate a preferred native resolution; each mode is a set of CRT timing values that define the duration and frequency of the horizontal/vertical sync, the positioning of the active display area, the horizontal resolution, vertical resolution, refresh rate.
For backward compatibility with displays using analog VGA signals, some of the contacts in the DVI connector carry the analog VGA signals. To ensure a basic level of interoperability, DVI compliant devices are required to support one baseline video mode, "low pixel format". Digitally encoded video pixel data is transported using multiple TMDS links. At the electrical level, these links are resistant to electrical noise and other forms of analog distortion. Green text A single link DVI connection consists of four TMDS links. Three of the links represent the RGB components of the video signal for a total of 24 bits per pixel; the fourth link carries the pixel clock. The binary data is encoded using 8b10b encoding. DVI does not use packetization, but rather transmits the pixel data as if it were a rasterized analog video signal; as such, the complete frame is drawn during each vertical refresh period. The full active area of each frame is always transmitted without compression. Video modes use horizontal and vertical refresh timings that are compatible with CRT displays, though this is not a requirement.
In single-link mode, the maximum pixel clock frequency is 165 MHz that supports a maximum resolution of 2.75 megapixels at 60 Hz refresh. For practical purposes, this allows a maximum 16:10 screen resolution of 1920 × 1200 at 60 Hz. To support higher-resolution display devices, the DVI specification contains a provision for dual link. Dual-link DVI doubles the number of TMDS pairs doubling the video bandwidth; as a result, higher resolutions up to 2560 × 1600 are supported at 60 Hz. The maximum length recommended for DVI cables is not included in the specification, since it is dependent on the pixel clock frequency. In general, cable lengths up to 4.5 metres will work for display resolutions up to 1920 × 1200. Longer cables up to 15 metres in length can be used with display resolutions lower. For greater distances, the use of a DVI booster—a signal repeater which may use an external power supply—is recommended to help mitigate signal degradation; the DVI connector on a device is given one of three names, depending on which signals it implements: DVI-I DVI-D DVI-A Most DVI connector types—the exception is DVI-A—have pins that pass digital video signals.
These come in two varieties: single link and dual link. Single link DVI employs a single 165 MHz transmitter that supports resolutions up to 1920 × 1200 at 60 Hz. Dual link DVI adds six pins, at the center of the connector, for a second transmitter increasing the bandwidth and supporting resolutions up to 2560 × 1600 at 60 Hz. A connector with these additional pins is sometimes referred to as DVI-DL. Dual link should not be confused with dual display, a configuration consisting of a single computer connected to two monitors, sometimes using a DMS-59 connector for two single link DVI connections. In addition to digital, some DVI connectors have pins that pass an analog signal, which can be used to connect an analog monitor; the analog pins are the four that surround the flat blade on a DVI-A connector. A VGA monitor, for example, can be connected to a video source with DVI-I through the use of a passive adapter. Since the analog pins are directly compatible