1.
D-subminiature
–
The D-subminiature or D-sub is a common type of electrical connector. They are named for their characteristic D-shaped metal shield, when they were introduced, D-subs were among the smallest connectors used on computer systems. The part containing pin contacts is called the male connector or plug, the sockets shield fits tightly inside the plugs shield. Panel mounted connectors usually have threaded nuts that accept screws on the cable end connector cover that are used for locking the connectors together, occasionally the nuts may be found on a cable end connector if it is expected to connect to another cable end. When screened cables are used, the shields are connected to the screens of the cables. This creates a continuous screen covering the whole cable and connector system. The D-sub series of connectors was introduced by Cannon in 1952, each shell size usually corresponds to a certain number of pins or sockets, A with 15, B with 25, C with 37, D with 50, and E with 9. For example, DB-25 denotes a D-sub with a 25-position shell size and this spacing is called normal density. The suffixes M and F are sometimes used instead of the original P and S for plug, later D-sub connectors added extra pins to the original shell sizes, and their names follow the same pattern. For example, the DE-15, usually found in VGA cables, has 15 pins in three rows, all surrounded by an E size shell, the pins are spaced at 0.090 inches horizontally and 0.078 inches vertically, in what is called high density. The other connectors with the pin spacing are the DA-26, DB-44, DC-62, DD-78. They all have three rows of pins, except the DD-78 which has four, and the DF-104 which has five rows in a new, the double density series of D-sub connectors features even denser arrangements and consists of the DE-19, DA-31, DB-52, DC-79, and DD-100. These each have three rows of pins, except the DD-100, which has four, however, this naming pattern is not always followed. It is now common to see DE-9 connectors sold as DB-9 connectors, DB-9 nearly always refers to a 9-pin connector with an E size shell. Cannon also produced combo D-subs with larger contacts in place of some of the contacts, for use for high-current, high-voltage. The DB-13W3 variant was used for high-performance video connections, this variant provided 10 regular pins plus three coaxial contacts for the red, green, and blue video signals. Some variants have current ratings up to 40 A or operating voltages as high as 13,500 V, others are waterproof, a smaller type of connector derived from the D-sub is called the microminiature D, or micro-D, which is a trademark of ITT Cannon. It is about half the length of a D-sub, a further family of connectors of similar appearance to the D-sub family uses names such as HD-50 and HD-68, and has a D-shaped shell about half the width of a DB25
2.
IBM PC compatible
–
IBM PC compatible computers are those similar to the original IBM PC, XT, and AT, able to run the same software and support the same expansion cards as those. Such computers used to be referred to as PC clones, or IBM clones, Columbia Data Products built the first clone of the IBM personal computer by a clean room implementation of its BIOS. Early IBM PC compatibles used the computer bus as the original PC. The IBM AT compatible bus was named the Industry Standard Architecture bus by manufacturers of compatible computers. The term IBM PC compatible is now a historical description only, only the Apple Macintosh classic Mac OS and macOS kept significant market share without compatibility with the IBM personal computer, so consumers are typically identified as being a PC or Mac user. IBM decided in 1980 to market a low-cost single-user computer as quickly as possible in response to Apple Computers success in the microcomputer market. On 12 August 1981, the first IBM PC went on sale, there were three operating systems available for it. The least expensive and most popular was PC DOS made by Microsoft, in a crucial concession, IBMs agreement allowed Microsoft to sell its own version, MS-DOS, for non-IBM computers. The only component of the original PC architecture exclusive to IBM was the BIOS and this software would run on any machine using MS-DOS or PC-DOS. Software that directly addressed the hardware instead of making standard calls was faster, however, software addressing IBM PC hardware in this way would not run on MS-DOS machines with different hardware. The 808x computer marketplace rapidly excluded all machines which were not hardware-, the 640 KB barrier on conventional system memory available to MS-DOS is a legacy of that period, other non-clone machines, while subject to a limit, could exceed 640 kB. Rumors of lookalike, compatible computers, created without IBMs approval, by June 1983 PC Magazine defined PC clone as a computer accommodate the user who takes a disk home from an IBM PC, walks across the room, and plugs it into the foreign machine. Because of a shortage of IBM PCs that year, many customers purchased clones instead, Columbia Data Products produced the first computer more or less compatible to the IBM PC standard during June 1982, soon followed by Eagle Computer. Compaq announced its first IBM PC compatible in November 1982, the Compaq Portable, the Compaq was the first sewing machine-sized portable computer that was essentially 100% PC-compatible. The company could not copy the BIOS directly as a result of the decision in Apple v. Franklin. Each computer would have its own Original Equipment Manufacturer version of MS-DOS, any software written for MS-DOS would operate on any MS-DOS computer, despite variations in hardware design. This expectation seemed reasonable in the marketplace of the time. Until then Microsoft was based primarily on computer languages such as BASIC, the established small system operating software was CP/M from Digital Research which was in use both at the hobbyist level and by the more professional of those using microcomputers
3.
Parallel port
–
A parallel port is a type of interface found on computers for connecting peripherals. The name refers to the way the data is sent, parallel ports send multiple bits of data at once, in parallel communication, as opposed to serial interfaces that send bits one at a time. To do this, parallel ports require multiple data lines in their cables and port connectors, there are many types of parallel ports, but the term has become most closely associated with the printer port or Centronics port found on most personal computers from the 1970s through the 2000s. Today, the port interface is virtually non-existent because of the rise of Universal Serial Bus devices, along with network printing using Ethernet. The parallel port interface was originally known as the Parallel Printer Adapter on IBM PC-compatible computers and it was primarily designed to operate printers that used IBMs 8-bit extended ASCII character set to print text, but could also be used to adapt other peripherals. Graphical printers, along with a host of other devices, have designed to communicate with the system. An Wang, Robert Howard and Prentice Robinson began development of a low-cost printer at Centronics, the printer used the dot matrix printing principle, with a print head consisting of a vertical row of seven metal pins connected to solenoids. When power was applied to the solenoids, the pin was pulled forward to strike the paper and leave a dot. On their original design, a typical glyph was printed as a matrix seven high and five wide, while the A models used a print head with 9 pins and this left the problem of sending the ASCII data to the printer. While a serial port does so with the minimum of pins and wires, it requires the device to buffer up the data as it arrives bit by bit, a parallel port makes this simpler, the entire ASCII value is presented on the pins in complete form. In addition to the seven pins, the system also needed various control pins as well as electrical grounds. Wang happened to have a stock of 20,000 Amphenol 36-pin micro ribbon connectors that were originally used for one of their early calculators. The interface only required 21 of these pins, the rest were grounded or not connected, the connector has become so closely associated with Centronics that it is now popularly known as the Centronics connector. The Centronics Model 101 printer, featuring this connector, was released in 1970, the host sent ASCII characters to the printer using 7 of 8 data pins, pulling them high to +5V to represent a 1. When the data was ready, the host pulled the STROBE pin low, the printer responded by pulling the BUSY line high, printing the character, and then returning BUSY to low again. The host could send another character. Control characters in the data caused other actions, like the CR or EOF, the host could also have the printer automatically start a new line by pulling the AUTOFEED line high, and keeping it there. The host had to watch the BUSY line to ensure it did not feed data to the printer too rapidly, especially given variable-time operations like a paper feed
4.
IBM
–
International Business Machines Corporation is an American multinational technology company headquartered in Armonk, New York, United States, with operations in over 170 countries. The company originated in 1911 as the Computing-Tabulating-Recording Company and was renamed International Business Machines in 1924, IBM manufactures and markets computer hardware, middleware and software, and offers hosting and consulting services in areas ranging from mainframe computers to nanotechnology. IBM is also a research organization, holding the record for most patents generated by a business for 24 consecutive years. IBM has continually shifted its business mix by exiting commoditizing markets and focusing on higher-value, also 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 worlds largest employers, with nearly 380,000 employees. Known as IBMers, IBM employees have been awarded five Nobel Prizes, six Turing Awards, ten National Medals of Technology, in the 1880s, technologies emerged that would ultimately form the core of what would become International Business Machines. 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 1,300 employees and offices and plants in Endicott and Binghamton, New York, Dayton, Ohio, Detroit, Michigan, Washington, D. C. and Toronto. They manufactured machinery for sale and lease, ranging from commercial scales and industrial time recorders, meat 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, Watson joined CTR as General Manager then,11 months later, was made President when court cases relating to his time at NCR were resolved. Having learned Pattersons pioneering business practices, Watson proceeded to put the stamp of NCR onto CTRs companies and his favorite slogan, THINK, became a mantra for each companys employees. During Watsons first four years, revenues more than doubled to $9 million, Watson had never liked the clumsy hyphenated title of the CTR and in 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, in 1937, IBMs tabulating equipment enabled organizations to process unprecedented amounts of data, its clients including the U. S. During the Second World War the company produced small arms for the American war effort, in 1949, Thomas Watson, Sr. created IBM World Trade Corporation, a subsidiary of IBM focused on foreign operations. In 1952, he stepped down after almost 40 years at the company helm, in 1957, the FORTRAN scientific programming language was developed. In 1961, IBM developed the SABRE reservation system for American Airlines, in 1963, IBM employees and computers helped NASA track the orbital flight of the Mercury astronauts. A year later it moved its headquarters from New York City to Armonk. The latter half of the 1960s saw IBM continue its support of space exploration, on April 7,1964, IBM announced the first computer system family, the IBM System/360
5.
USB
–
It is currently developed by the USB Implementers Forum. USB was designed to standardize the connection of peripherals to personal computers. It has become commonplace on other devices, such as smartphones, PDAs, USB has effectively replaced a variety of earlier interfaces, such as serial ports and parallel ports, as well as separate power chargers for portable devices. Also, there are 5 modes of USB data transfer, in order of increasing bandwidth, Low Speed, Full Speed, High Speed, SuperSpeed, USB devices have some choice of implemented modes, and USB version is not a reliable statement of implemented modes. Modes are identified by their names and icons, and the specifications suggests that plugs, unlike other data buses, USB connections are directed, with both upstream and downstream ports emanating from a single host. This applies to power, with only downstream facing ports providing power. Thus, USB cables have different ends, A and B, therefore, in general, each different format requires four different connectors, a plug and receptacle for each of the A and B ends. USB cables have the plugs, and the corresponding receptacles are on the computers or electronic devices, in common practice, the A end is usually the standard format, and the B side varies over standard, mini, and micro. The mini and micro formats also provide for USB On-The-Go with a hermaphroditic AB receptacle, the micro format is the most durable from the point of view of designed insertion lifetime. The standard and mini connectors have a lifetime of 1,500 insertion-removal cycles. Likewise, the component of the retention mechanism, parts that provide required gripping force, were also moved into plugs on the cable side. A group of seven companies began the development of USB in 1994, Compaq, DEC, IBM, Intel, Microsoft, NEC, a team including Ajay Bhatt worked on the standard at Intel, the first integrated circuits supporting USB were produced by Intel in 1995. The original USB1.0 specification, which was introduced in January 1996, Microsoft Windows 95, OSR2.1 provided OEM support for the devices. The first widely used version of USB was 1.1, the 12 Mbit/s data rate was intended for higher-speed devices such as disk drives, and the lower 1.5 Mbit/s rate for low data rate devices such as joysticks. Apple Inc. s iMac was the first mainstream product with USB, following Apples design decision to remove all legacy ports from the iMac, many PC manufacturers began building legacy-free PCs, which led to the broader PC market using USB as a standard. The USB2.0 specification was released in April 2000 and was ratified by the USB Implementers Forum at the end of 2001.1 specification, the USB3.0 specification was published on 12 November 2008. Its main goals were to increase the transfer rate, decrease power consumption, increase power output. USB3.0 includes a new, higher speed bus called SuperSpeed in parallel with the USB2.0 bus, for this reason, the new version is also called SuperSpeed
6.
Micro ribbon connector
–
The micro ribbon or miniature ribbon connector is a common type of electrical connector used particularly in computer and telecommunications applications. They have a characteristic D-shaped metal shield similar to that used in D-subminiature connectors and this connector type is also known as Telco, 25-pair, Miniature Delta Ribbon, Mini D Ribbon, Delta ribbon, MDR, Amphenol, or CHAMP miniature ribbon connector. Although it was invented by Amphenol, many companies now produce it, such as 3M, Cinch Connectors, TE Connectivity and these names may or may not be ambiguous as to physical size. There are at least two sizes, as well as different numbers of contacts, and various means of holding the mated connectors together, the larger size has 0.085 inch contact pitch. This size, with 36 pins and bail locks, is known as a Centronics connector. Other connectors of this size are also called Centronics connectors, the smaller size has 0.050 inch pitch. This size, with 36 pins, is known as a mini-Centronics connector. Other connectors of this size are also called mini-Centronics connectors, a micro ribbon connector contains two parallel rows of pins within a shielded case. There are 14-, 24-, 36-, 50-, 64-, contact is achieved by means of solder, crimping or insulation displacement. Female connectors have bail locks for a connection to the male connector. In the telecommunications sector screws are used instead, since a loose connector would have a greater impact, 24-pin connector, IEEE488 interface 36-pin connector, IEEE1284 parallel interface 50-pin connector, SCSI-1 interface 50-pin connector, RJ21X telco connector Ribbon cable 25-pair color code
7.
Direct current
–
Direct current is a flow of electrical charge carriers that always takes place in the same direction. The current need not always have the magnitude, but if it is to be defined as dc. This contrasts with alternating current which varies the direction of flow, sources of direct current include power supplies, electrochemical cells and batteries, and photovoltaic cells and panels. The intensity, or amplitude, of a direct current might fluctuate with time, in some such cases the dc has an ac component superimposed on it. An example of this is the output of a cell that receives a modulated light communications signal. A source of dc is sometimes called a dc generator, batteries and various other sources of dc produce a constant voltage. This is called pure dc and can be represented by a straight, the peak and effective values are the same. The peak to peak value is zero because the instantaneous amplitude never changes, in some instances the value of a dc voltage pulsates or oscillates rapidly with time, in a manner similar to the changes in an ac wave. The unfiltered output of a wave or a full wave rectifier. In 1820, Hans Christian Orsted discovered that electrical current creates a magnetic field and this discovery made scientists relate magnetism to the electric phenomena. In 1879, Thomas Edison invented the light bulb. He improved a 50-year-old idea using lower current electricity, a vacuum inside the globe and a small carbonized filament. At that time, the idea of lightning was not new. Edison not only invented an incandescent electric light, but an electric lighting system contained all the necessary elements to make the incandescent light safe, economical. Prior to 1879, direct current electricity had been used in lighting for the outdoors and it was in the 1880s when the modern electric utility industry began. It was an evolution from street lighting systems and from gas and it was located in Lower Manhattan, on Pearl Street. This station provided light and electricity to customers in a one square mile range, the station was called Thomas Edisons Pearl Street Electricity Generating Station. This station introduced four elements of an electric utility system, Efficient distribution, competitive price, reliable central generation
8.
Megabyte
–
The megabyte is a multiple of the unit byte for digital information. Its recommended unit symbol is MB, but sometimes MByte is used, the unit prefix mega is a multiplier of 1000000 in the International System of Units. Therefore, one megabyte is one million bytes of information and this definition has been incorporated into the International System of Quantities. However, in the computer and information fields, several other definitions are used that arose for historical reasons of convenience. A common usage has been to one megabyte as 1048576bytes. However, most standards bodies have deprecated this usage in favor of a set of binary prefixes, less common is a convention that used the megabyte to mean 1000×1024 bytes. The megabyte is commonly used to measure either 10002 bytes or 10242 bytes, the interpretation of using base 1024 originated as a compromise technical jargon for the byte multiples that needed to be expressed by the powers of 2 but lacked a convenient name. As 1024 approximates 1000, roughly corresponding to the SI prefix kilo-, in 1998 the International Electrotechnical Commission proposed standards for binary prefixes requiring the use of megabyte to strictly denote 10002 bytes and mebibyte to denote 10242 bytes. By the end of 2009, the IEC Standard had been adopted by the IEEE, EU, ISO, the Mac OS X10.6 file manager is a notable example of this usage in software. Since Snow Leopard, file sizes are reported in decimal units, base 21 MB =1048576 bytes is the definition used by Microsoft Windows in reference to computer memory, such as RAM. This definition is synonymous with the binary prefix mebibyte. Mixed 1 MB =1024000 bytes is the used to describe the formatted capacity of the 1.44 MB3. 5inch HD floppy disk. Semiconductor memory doubles in size for each address lane added to an integrated circuit package, the capacity of a disk drive is the product of the sector size, number of sectors per track, number of tracks per side, and the number of disk platters in the drive. Changes in any of these factors would not usually double the size, sector sizes were set as powers of two for convenience in processing. It was an extension to give the capacity of a disk drive in multiples of the sector size, giving a mix of decimal. Depending on compression methods and file format, a megabyte of data can roughly be, a 4 megapixel JPEG image with normal compression. Approximately 1 minute of 128 kbit/s MP3 compressed music,6 seconds of uncompressed CD audio. A typical English book volume in plain text format, the human genome consists of DNA representing 800 MB of data
9.
Electrical connector
–
An electrical connector, is an electro-mechanical device used to join electrical terminations and create an electrical circuit. Electrical connectors consist of plugs and jacks, the connection may be temporary, as for portable equipment, require a tool for assembly and removal, or serve as a permanent electrical joint between two wires or devices. An adapter can be used to bring together dissimilar connectors. There are hundreds of types of electrical connectors, connectors may join two lengths of flexible copper wire or cable, or connect a wire or cable to an electrical terminal. In computing, a connector can also be known as a physical interface. Cable glands, known as cable connectors in the US, connect wires to devices rather than electrically and are distinct from quick-disconnects performing the latter. It is usually desirable for a connector to be easy to visually, rapid to assemble, require only simple tooling. In some cases an equipment manufacturer might choose a connector specifically because it is not compatible with those other sources. No single connector has all the properties, the proliferation of types is a reflection of differing requirements. Fretting is a failure mode in electrical connectors that have not been specifically designed to prevent it. Many connectors are keyed, with some mechanical component which prevents mating except with a correctly oriented matching connector, some connector housings are designed with locking mechanisms to prevent inadvertent disconnection or poor environmental sealing. Locking mechanism designs include locking levers of various sorts, screw locking, a terminal is a simple type of electrical connector that connects two or more wires to a single connection point. Wire nuts are another type of single point connector, terminal blocks provide a convenient means of connecting individual electrical wires without a splice or physically joining the ends. They are usually used to connect wiring among various items of equipment within an enclosure or to make connections among individually enclosed items. Since terminal blocks are available for a wide range of wire sizes and terminal quantity. One type of terminal block accepts wires that are prepared only by removing a short length of insulation from the end, another type accepts wires that have ring or spade terminal lugs crimped onto the wires. Printed circuit board mounted terminal blocks allow individual wires to be connected to the circuit board, a general type of connector that simply screws or clamps bare wire to a post, such connectors are frequently used in electronic test equipment and audio. Many, but not all binding posts will also accept a banana connector plug, since stripping the insulation from wires is time-consuming, many connectors intended for rapid assembly use insulation-displacement connectors so that insulation need not be removed from the wire
10.
Computer
–
A computer is a device that can be instructed to carry out an arbitrary set of arithmetic or logical operations automatically. The ability of computers to follow a sequence of operations, called a program, such computers are used as control systems for a very wide variety of industrial and consumer devices. The Internet is run on computers and it millions of other computers. Since ancient times, simple manual devices like the abacus aided people in doing calculations, early in the Industrial Revolution, some mechanical devices were built to automate long tedious tasks, such as guiding patterns for looms. More sophisticated electrical machines did specialized analog calculations in the early 20th century, the first digital electronic calculating machines were developed during World War II. The speed, power, and versatility of computers has increased continuously and dramatically since then, conventionally, a modern computer consists of at least one processing element, typically a central processing unit, and some form of memory. The processing element carries out arithmetic and logical operations, and a sequencing, peripheral devices include input devices, output devices, and input/output devices that perform both functions. Peripheral devices allow information to be retrieved from an external source and this usage of the term referred to a person who carried out calculations or computations. The word continued with the same meaning until the middle of the 20th century, from the end of the 19th century the word began to take on its more familiar meaning, a machine that carries out computations. The Online Etymology Dictionary gives the first attested use of computer in the 1640s, one who calculates, the Online Etymology Dictionary states that the use of the term to mean calculating machine is from 1897. The Online Etymology Dictionary indicates that the use of the term. 1945 under this name, theoretical from 1937, as Turing machine, devices have been used to aid computation for thousands of years, mostly using one-to-one correspondence with fingers. The earliest counting device was probably a form of tally stick, later record keeping aids throughout the Fertile Crescent included calculi which represented counts of items, probably livestock or grains, sealed in hollow unbaked clay containers. The use of counting rods is one example, the abacus was initially used for arithmetic tasks. The Roman abacus was developed from used in Babylonia as early as 2400 BC. Since then, many forms of reckoning boards or tables have been invented. In a medieval European counting house, a checkered cloth would be placed on a table, the Antikythera mechanism is believed to be the earliest mechanical analog computer, according to Derek J. de Solla Price. It was designed to calculate astronomical positions and it was discovered in 1901 in the Antikythera wreck off the Greek island of Antikythera, between Kythera and Crete, and has been dated to circa 100 BC
11.
Personal computer
–
A personal computer is a multi-purpose electronic computer whose size, capabilities, and price make it feasible for individual use. PCs are intended to be operated directly by a end-user, rather than by an expert or technician. In the 2010s, PCs are typically connected to the Internet, allowing access to the World Wide Web, personal computers may be connected to a local area network, either by a cable or a wireless connection. In the 2010s, a PC may be, a multi-component desktop computer, designed for use in a location a laptop computer, designed for easy portability or a tablet computer. In the 2010s, PCs run using a system, such as Microsoft Windows, Linux. The very earliest microcomputers, equipped with a front panel, required hand-loading of a program to load programs from external storage. Before long, automatic booting from permanent read-only memory became universal, in the 2010s, users have access to a wide range of commercial software, free software and free and open-source software, which are provided in ready-to-run or ready-to-compile form. Since the early 1990s, Microsoft operating systems and Intel hardware have dominated much of the computer market, first with MS-DOS. Alternatives to Microsofts Windows operating systems occupy a minority share of the industry and these include Apples OS X and free open-source Unix-like operating systems such as Linux and Berkeley Software Distribution. Advanced Micro Devices provides the alternative to Intels processors. PC is an initialism for personal computer, some PCs, including the OLPC XOs, are equipped with x86 or x64 processors but not designed to run Microsoft Windows. PC is used in contrast with Mac, an Apple Macintosh computer and this sense of the word is used in the Get a Mac advertisement campaign that ran between 2006 and 2009, as well as its rival, Im a PC campaign, that appeared in 2008. Since Apples transition to Intel processors starting 2005, all Macintosh computers are now PCs, the “brain” may one day come down to our level and help with our income-tax and book-keeping calculations. But this is speculation and there is no sign of it so far, in the history of computing there were many examples of computers designed to be used by one person, as opposed to terminals connected to mainframe computers. Using the narrow definition of operated by one person, the first personal computer was the ENIAC which became operational in 1946 and it did not meet further definitions of affordable or easy to use. An example of an early single-user computer was the LGP-30, created in 1956 by Stan Frankel and used for science and it came with a retail price of $47, 000—equivalent to about $414,000 today. Introduced at the 1965 New York Worlds Fair, the Programma 101 was a programmable calculator described in advertisements as a desktop computer. It was manufactured by the Italian company Olivetti and invented by the Italian engineer Pier Giorgio Perotto, the Soviet MIR series of computers was developed from 1965 to 1969 in a group headed by Victor Glushkov
12.
Serial interface
–
In telecommunication and data transmission, serial communication is the process of sending data one bit at a time, sequentially, over a communication channel or computer bus. This is in contrast to parallel communication, where bits are sent as a whole. Serial communication is used for all communication and most computer networks. The migration from PCI to PCI Express is an example, many serial communication systems were originally designed to transfer data over relatively large distances through some sort of data cable. Practically all long-distance communication transmits data one bit at a time, rather than in parallel, the cables that carry this data and the computer ports they plug into are usually referred to with a more specific name, to reduce confusion. Keyboard and mouse cables and ports are almost invariably serial—such as PS/2 port and Apple Desktop Bus, many communication systems were generally originally designed to connect two integrated circuits on the same printed circuit board, connected by signal traces on that board. Integrated circuits are more expensive when they have more pins, to reduce the number of pins in a package, many ICs use a serial bus to transfer data when speed is not important. Some examples of such low-cost serial buses include SPI, I²C, dc-bus, UNI/O, the communication links across which computers—or parts of computers—talk to one another may be either serial or parallel. A parallel link transmits several streams of data simultaneously along multiple channels, whereas, several factors allow serial to be clocked at a higher rate, Clock skew between different channels is not an issue. A serial connection requires fewer interconnecting cables and hence occupies less space, the extra space allows for better isolation of the channel from its surroundings. Crosstalk is less of an issue, because there are fewer conductors in proximity, in many cases, serial is cheaper to implement than parallel. Many ICs have serial interfaces, as opposed to parallel ones, so that they have fewer pins and are therefore less expensive
13.
IEEE 1284
–
IEEE1284 is a standard that defines bi-directional parallel communications between computers and other devices. It was originally developed in the 1970s by Centronics, and was known as the Centronics port. In the 1970s, Centronics developed the now-familiar printer parallel port that became a de facto standard. Centronics had introduced the first successful low-cost seven-wire print head, which used a series of solenoids to pull the metal pins to strike a ribbon. A dot matrix print head consists of a series of pins arranged in a vertical row. Each pin is attached to some sort of actuator, a solenoid in the case of Centronics, which can pull the pin forward to strike a ribbon and the paper. The entire print head is moved horizontally in order to print a line of text, character sets on early printers normally used 7 by 5 pixels to produce 80-column text. As printers grew in sophistication, and the cost of memory dropped, printers began adding increasing amounts of buffer memory, the original port design was send-only, allowing data to be sent from the host computer to the printer. Separate pins in the port allow status information to be sent back to the computer and this was a serious limitation as printers became smarter and a richer set of status codes were desired. This led to an expansion of the system introduced by HP. This used the status pins of the port to form a 4-bit parallel port for sending arbitrary data back to the host.5 MByte/s. In 1991 the Network Printing Alliance was formed to develop a new standard, in March 1994, the IEEE1284 specification was released. 1284 included all of these modes, and allowed operation in any of them, in the printer venue, this allows for faster printing and back-channel status and management. Since the new standard allowed the peripheral to send large amounts of data back to the host and this included scanners, tape drives, hard disks, computer networks connected directly via parallel interface, network adapters and other devices. No longer was the required to purchase an expensive SCSI card—they could simply use their built-in parallel interface. The parallel interface has since been displaced by local area network interfaces. IEEE1284 can operate in five modes, Compatibility Mode, also known as Centronics standard or SPP, is an implementation with only a few differences from the original Centronics design. This mode is almost exclusively used for printers, the only signals that the printer can send back to the host are some fixed-meaning status lines that signal common error conditions, such as the printer running out of paper
14.
Ethernet
–
Ethernet /ˈiːθərnɛt/ is a family of computer networking technologies commonly used in local area networks, metropolitan area networks and wide area networks. It was commercially introduced in 1980 and first standardized in 1983 as IEEE802.3, over time, Ethernet has largely replaced competing wired LAN technologies such as token ring, FDDI and ARCNET. The original 10BASE5 Ethernet uses coaxial cable as a medium, while the newer Ethernet variants use twisted pair. Over the course of its history, Ethernet data transfer rates have increased from the original 2.94 megabits per second to the latest 100 gigabits per second. The Ethernet standards comprise several wiring and signaling variants of the OSI physical layer in use with Ethernet, systems communicating over Ethernet divide a stream of data into shorter pieces called frames. As per the OSI model, Ethernet provides services up to, since its commercial release, Ethernet has retained a good degree of backward compatibility. Features such as the 48-bit MAC address and Ethernet frame format have influenced other networking protocols, the primary alternative for some uses of contemporary LANs is Wi-Fi, a wireless protocol standardized as IEEE802.11. Ethernet was developed at Xerox PARC between 1973 and 1974 and it was inspired by ALOHAnet, which Robert Metcalfe had studied as part of his PhD dissertation. In 1975, Xerox filed a patent application listing Metcalfe, David Boggs, Chuck Thacker, in 1976, after the system was deployed at PARC, Metcalfe and Boggs published a seminal paper. Metcalfe left Xerox in June 1979 to form 3Com and he convinced Digital Equipment Corporation, Intel, and Xerox to work together to promote Ethernet as a standard. The so-called DIX standard, for Digital/Intel/Xerox, specified 10 Mbit/s Ethernet, with 48-bit destination and source addresses and it was published on September 30,1980 as The Ethernet, A Local Area Network. Data Link Layer and Physical Layer Specifications, version 2 was published in November,1982 and defines what has become known as Ethernet II. Formal standardization efforts proceeded at the time and resulted in the publication of IEEE802.3 on June 23,1983. Ethernet initially competed with two largely proprietary systems, Token Ring and Token Bus, in the process, 3Com became a major company. 3Com shipped its first 10 Mbit/s Ethernet 3C100 NIC in March 1981, an Ethernet adapter card for the IBM PC was released in 1982, and, by 1985, 3Com had sold 100,000. Parallel port based Ethernet adapters were produced for a time, with drivers for DOS, by the early 1990s, Ethernet became so prevalent that it was a must-have feature for modern computers, and Ethernet ports began to appear on some PCs and most workstations. This process was sped up with the introduction of 10BASE-T and its relatively small modular connector. Since then, Ethernet technology has evolved to meet new bandwidth, in addition to computers, Ethernet is now used to interconnect appliances and other personal devices
15.
Wi-Fi
–
Wi-Fi or WiFi is a technology for wireless local area networking with devices based on the IEEE802.11 standards. Wi-Fi is a trademark of the Wi-Fi Alliance, which restricts the use of the term Wi-Fi Certified to products that successfully complete interoperability certification testing. Devices that can use Wi-Fi technology include personal computers, video-game consoles, smartphones, digital cameras, tablet computers, digital audio players, Wi-Fi compatible devices can connect to the Internet via a WLAN network and a wireless access point. Such an access point has a range of about 20 meters indoors, hotspot coverage can be as small as a single room with walls that block radio waves, or as large as many square kilometres achieved by using multiple overlapping access points. Wi-Fi most commonly uses the 2.4 gigahertz UHF and 5 gigahertz SHF ISM radio bands, having no physical connections, it is more vulnerable to attack than wired connections, such as Ethernet. In 1971, ALOHAnet connected the Hawaiian Islands with a UHF wireless packet network, ALOHAnet and the ALOHA protocol were early forerunners to Ethernet, and later the IEEE802.11 protocols, respectively. A1985 ruling by the U. S. Federal Communications Commission released the ISM band for unlicensed use and these frequency bands are the same ones used by equipment such as microwave ovens and are subject to interference. In 1991, NCR Corporation with AT&T Corporation invented the precursor to 802.11, the first wireless products were under the name WaveLAN. They are the credited with inventing Wi-Fi. In 1992 and 1996, CSIRO obtained patents for a method used in Wi-Fi to unsmear the signal. The first version of the 802.11 protocol was released in 1997 and this was updated in 1999 with 802. 11b to permit 11 Mbit/s link speeds, and this proved to be popular. In 1999, the Wi-Fi Alliance formed as an association to hold the Wi-Fi trademark under which most products are sold. Wi-Fi uses a number of patents held by many different organizations. In April 2009,14 technology companies agreed to pay CSIRO $1 billion for infringements on CSIRO patents and this led to Australia labeling Wi-Fi as an Australian invention, though this has been the subject of some controversy. In 2016, the local area network Test Bed was chosen as Australias contribution to the exhibition A History of the World in 100 Objects held in the National Museum of Australia. The name Wi-Fi, commercially used at least as early as August 1999, was coined by the brand-consulting firm Interbrand, the Wi-Fi Alliance had hired Interbrand to create a name that was a little catchier than IEEE802. 11b Direct Sequence. Phil Belanger, a member of the Wi-Fi Alliance who presided over the selection of the name Wi-Fi, has stated that Interbrand invented Wi-Fi as a pun upon the word hi-fi. Interbrand also created the Wi-Fi logo, the yin-yang Wi-Fi logo indicates the certification of a product for interoperability
16.
PC compatible
–
IBM PC compatible computers are those similar to the original IBM PC, XT, and AT, able to run the same software and support the same expansion cards as those. Such computers used to be referred to as PC clones, or IBM clones, Columbia Data Products built the first clone of the IBM personal computer by a clean room implementation of its BIOS. Early IBM PC compatibles used the computer bus as the original PC. The IBM AT compatible bus was named the Industry Standard Architecture bus by manufacturers of compatible computers. The term IBM PC compatible is now a historical description only, only the Apple Macintosh classic Mac OS and macOS kept significant market share without compatibility with the IBM personal computer, so consumers are typically identified as being a PC or Mac user. IBM decided in 1980 to market a low-cost single-user computer as quickly as possible in response to Apple Computers success in the microcomputer market. On 12 August 1981, the first IBM PC went on sale, there were three operating systems available for it. The least expensive and most popular was PC DOS made by Microsoft, in a crucial concession, IBMs agreement allowed Microsoft to sell its own version, MS-DOS, for non-IBM computers. The only component of the original PC architecture exclusive to IBM was the BIOS and this software would run on any machine using MS-DOS or PC-DOS. Software that directly addressed the hardware instead of making standard calls was faster, however, software addressing IBM PC hardware in this way would not run on MS-DOS machines with different hardware. The 808x computer marketplace rapidly excluded all machines which were not hardware-, the 640 KB barrier on conventional system memory available to MS-DOS is a legacy of that period, other non-clone machines, while subject to a limit, could exceed 640 kB. Rumors of lookalike, compatible computers, created without IBMs approval, by June 1983 PC Magazine defined PC clone as a computer accommodate the user who takes a disk home from an IBM PC, walks across the room, and plugs it into the foreign machine. Because of a shortage of IBM PCs that year, many customers purchased clones instead, Columbia Data Products produced the first computer more or less compatible to the IBM PC standard during June 1982, soon followed by Eagle Computer. Compaq announced its first IBM PC compatible in November 1982, the Compaq Portable, the Compaq was the first sewing machine-sized portable computer that was essentially 100% PC-compatible. The company could not copy the BIOS directly as a result of the decision in Apple v. Franklin. Each computer would have its own Original Equipment Manufacturer version of MS-DOS, any software written for MS-DOS would operate on any MS-DOS computer, despite variations in hardware design. This expectation seemed reasonable in the marketplace of the time. Until then Microsoft was based primarily on computer languages such as BASIC, the established small system operating software was CP/M from Digital Research which was in use both at the hobbyist level and by the more professional of those using microcomputers
17.
Dot matrix printing
–
However, unlike a typewriter or daisy wheel printer, letters are drawn out of a dot matrix, and thus, varied fonts and arbitrary graphics can be produced. Each dot is produced by a metal rod, also called a wire or pin. Facing the ribbon and the paper is a guide plate named ribbon mask holder or protector. It is pierced with holes to serve as guides for the pins and this plate may be made of hard plastic or an artificial jewel such as sapphire or ruby. The portion of the containing the pins is called the print head. When running the printer, it generally prints one line of text at a time, there are two approaches to achieve this, The common serial dot matrix printers use a horizontally moving print head. The print head can be thought of featuring a vertical column of seven or more pins approximately the height of a character box. Thereby, up to 48 pins can be used to form the characters of a line while the print head moves horizontally. In a considerably different configuration, so called line dot matrix printers use a print head almost as wide as the paper path utilizing a horizontal line of thousands of pins for printing. Sometimes two horizontally slightly displaced rows are used to improve the effective dot density through interleaving, while still line-oriented, these printers for the professional heavy-duty market effectively print a whole line at once while the paper moves forward below the print head. The printing speed of serial dot matrix printers with moving heads varies from 30 to 1550 cps, in contrast to this, line matrix printers are capable of printing much more than 1000 cps, resulting in a throughput of up to 800 pages/hour. Because the printing involves mechanical pressure, both of these types of printers can create carbon copies and carbonless copies and these machines can be highly durable. A variation on the dot matrix printer was the cross hammer dot printer, the smooth cylindrical roller of a conventional printer was replaced by a spinning, fluted cylinder. The print head was a hammer, with a vertical projecting edge. Where the vertical edge of the hammer intersected the horizontal flute of the cylinder, compressing the paper, characters were built up of multiple dots. Although nearly all inkjet, thermal, and laser printers also print closely spaced dots rather than lines or characters. In 1925, Rudolf Hell invented the Hellschreiber, an early facsimile-like dot matrix-based teletypewriter device, like the earlier Hellschreiber, it still used electromechanical means of coding and decoding, but it used a start-stop method rather than synchronous transmission for communication. In 1956, while he was employed at Telefonbau und Normalzeit GmbH, the device was introduced to the Deutsche Bundespost, when Preikschat emigrated into the USA in 1957 he sold the rights to utilize the applications in any countries to TuN
18.
Extended ASCII
–
The term extended ASCII refers to eight-bit or larger character encodings that include the standard seven-bit ASCII characters, plus additional characters. There are many extended ASCII encodings, EBCDIC likewise developed many extended variants over the decades. ASCII was designed in the 1960s for teleprinters and telegraphy, early teleprinters were electromechanical, having no microprocessor and just enough electromechanical memory to function. They fully processed one character at a time, returning to a state immediately afterward. They were typewriter-derived impact printers, and could print a fixed set of glyphs. The number of characters was deliberately kept small, to keep teleprinters. Some popular peripherals only implemented a 64-printing-character subset, Teletype Model 33 could not transmit a through z or five less-common symbols, and when they received such characters they instead printed A through Z and five other mostly-similar symbols. The ASCII character set is large enough for general use. The biggest problem for users around the world was other alphabets. ASCIIs English alphabet almost accommodates European languages, if accented letters are replaced by non-accented letters or two-character approximations, languages with dissimilar basic alphabets could use transliteration. Users were not comfortable with such compromises, at least 29 variant sets resulted. 12 code points were modified by at least one modified set, there was always temptation to make a larger character set, but there was no easy path forward. There was no way to define a universal extension, there was no hardware to print or display an extended set. For years, applications were designed around the 64-character set and/or the 95-character set, seven-bit ASCII encodes only 128 characters. An eight-bit character set encodes 256 characters, so it can include ASCII plus 128 more characters, conversion requires a custom map from one character set to the other, or a description of both character sets from which the map can be generated. If any characters in the text are not defined in the character set. Even one unconvertible character can mean failure of conversion, or the converter can substitute a similar character or a warning character, when characters are substituted, a human should inspect and possibly modify the output text, possibly examining the input text. Various proprietary modifications and extensions of ASCII appeared on non-EBCDIC mainframe computers and minicomputers, hewlett-Packard started to add European characters to their extended 7-bit / 8-bit ASCII character set HP Roman Extension around 1978/1979 for use with their workstations, terminals and printers
19.
Centronics
–
Centronics Data Computer Corporation was an American manufacturer of computer printers, now remembered primarily for the parallel interface that bears its name. Centronics began as a division of Wang Laboratories, founded and initially operated by Robert Howard and Samuel Lang, the group produced remote terminals and systems for the casino industry. Printers were developed to print receipts and transaction reports, Wang spun off the business in 1971 and Centronics was formed as a corporation in Hudson, New Hampshire with Howard as president and chairman. The Centronics Model 101 was introduced at the 1970 National Computer Conference, the print head used an innovative seven-wire solenoid impact system. Based on this design, Centronics later made the claim to have developed the first dot matrix impact printer, a business relationship developed when Centronics needed reliable manufacturing of the printer mechanisms—a relationship that would help propel Brother into the printer industry. Hugel would later become vice president of Centronics. Print heads and electronics were built in Centronics plants in New Hampshire and Ireland, mechanisms were built in Japan by Brother, in the 1970s, Centronics formed a relationship with Canon to develop non-impact printers. No products were produced, but Canon continued to work on laser printers. In 1977, Centronics sued competitor Mannesmann AG in a patent dispute regarding the spring used in the print actuator. In 1975, Centronics formed an OEM agreement with Tandy and produced DMP, the 6000 series band printers were introduced in 1978. By 1979 company revenues were over $100 million, in 1980, the Mini-Printer Model 770 was introduced—a small, low-cost desktop serial matrix printer. This was the first printer built completely in-house, and there were problems, flaws in the microprocessor led to a recall and a stoppage of manufacturing for a year. During this period, Epson, Brother and others began to market share. 1980 also saw the introduction of the E Series 900 and 1200 LPM band printers, in 1982, Control Data Corporation merged their current printer business unit, CPI, into Centronics and at the same time invested $25 million in the company, effectively taking control from Howard. Control Data controlled the company until 1986 when CDCs interest was acquired by a group of investors affiliated with Drexel Burnham Lambert, the Drexel interest was acquired by Centronics in 1987. The LineWriter 400 band printer was introduced in 1983, closely followed by the faster LineWriter 800 band printer in 1984, the LineWriter series would continue through 1995. The GLP was a series of low-end serial matrix printers introduced in 1984, the relationship with Brother continued with several of the PrintStation models being produced from rebadged Brother products. Exclusive rights to market Trilog color matrix printers was acquired in 1984, advanced Terminals and BDS Computer Australia Pty Ltd were purchased in 1986
20.
Wang Laboratories
–
Wang Laboratories was a computer company founded in 1951, by Dr. The company was headquartered in Cambridge, Massachusetts, Tewksbury, Massachusetts. At its peak in the 1980s, Wang Laboratories had annual revenues of $3 billion and it was one of the leading companies during the time of the Massachusetts Miracle. The company was directed by Dr. Wang, who was described as a leader and played a personal role in setting business. Under his direction, the company went through several transitions between different product lines. Wang Laboratories filed for protection in August 1992. After emerging from bankruptcy, the company changed its name to Wang Global. An Wang took steps to ensure that the Wang family would retain control of the company even after going public and he created a second class of stock, class B, with higher dividends, but only one-tenth the voting power of class C. The public mostly bought class B shares, the Wang family retained most of the class C shares, the companys first major project was the Linasec in 1964. It was a special purpose computer, designed to justify papertape for use on automated Linotype machines. It was developed under contract to Compugraphic, who manufactured phototypesetters, Compugraphic retained the rights to manufacture the Linasec without royalty. They exercised these rights, effectively forcing Wang out of the market, the Wang LOCI-2 Logarithmic Computing Instrument desktop calculator was introduced in January 1965. Using factor combining it was probably the first desktop calculator capable of computing logarithms, the electronics included 1,275 discrete transistors. It actually performed multiplication by adding logarithms, and roundoff in the conversion was noticeable,2 times 2 yielded 3.999999999. From 1965 to about 1971, Wang was a well-regarded calculator company, Wang calculators cost in the mid-four-figures, used Nixie tube readouts, performed transcendental functions, had varying degrees of programmability, and exploited magnetic core memory. The 200 and 300 calculator models were available as timeshared simultaneous packages that had a processing unit connected by cables leading to four individual desktop display/keyboard units. Competition included HP, which introduced the HP 9100A in 1968, one perhaps apocryphal story tells of a banker who spot-checked a Wang calculator against a mortgage table and found a discrepancy. The calculator was right, the tables were wrong
21.
Computer terminal
–
A computer terminal is an electronic or electromechanical hardware device that is used for entering data into, and displaying data from, a computer or a computing system. The function of a terminal is confined to display and input of data, a terminal that depends on the host computer for its processing power is called a dumb terminal or thin client. A personal computer can run terminal emulator software that replicates the function of a terminal, sometimes allowing concurrent use of local programs and access to a distant terminal host system. The terminal of the first working programmable, fully automatic digital Turing-complete computer, the Z3, had a keyboard, early user terminals connected to computers were electromechanical teleprinters/teletypewriters, such as the Teletype Model 33 ASR, originally used for telegraphy or the Friden Flexowriter. Later printing terminals such as the DECwriter LA30 were developed, however printing terminals were limited by the speed at which paper could be printed, and for interactive use the paper record was unnecessary. The problem was that the amount of memory needed to store the information on a page of text was comparable to the memory in low end minicomputers then in use. Displaying the information at video speeds was also a challenge and the control logic took up a rack worth of pre-integrated circuit electronics. Another approach involved the use of the tube, a specialized CRT developed by Tektronix that retained information written on it without the need to refresh. The Datapoint 3300 from Computer Terminal Corporation was announced in 1967 and shipped in 1969 and it solved the memory space issue mentioned above by using a digital shift-register design, and using only 72 columns rather than the later more common choice of 80. Some type of blinking cursor that can be positioned, the term intelligent in this context dates from 1969. Notable examples include the IBM2250 and IBM2260, predecessors to the IBM3270, providing even more processing possibilities, workstations like the Televideo TS-800 could run CP/M-86, blurring the distinction between terminal and Personal Computer. Most terminals were connected to minicomputers or mainframe computers and often had a green or amber screen, typically terminals communicate with the computer via a serial port via a null modem cable, often using an EIA RS-232 or RS-422 or RS-423 or a current loop serial interface. In fact, the design for the Intel 8008 was originally conceived at Computer Terminal Corporation as the processor for the Datapoint 2200. While early IBM PCs had single color green screens, these screens were not terminals. The screen of a PC did not contain any character generation hardware, all signals and video formatting were generated by the video display card in the PC, or by the CPU. An IBM PC monitor, whether it was the monochrome display or the 16-color display, was technically much more similar to an analog TV set than to a terminal. With suitable software a PC could, however, emulate a terminal, the Data General One could be booted into terminal emulator mode from its ROM. Since the advent and subsequent popularization of the computer, few genuine hardware terminals are used to interface with computers today
22.
Solenoid
–
A solenoid is a coil wound into a tightly packed helix. The term was invented by French physicist André-Marie Ampère to designate a helical coil, a solenoid is a type of electromagnet when the purpose is to generate a controlled magnetic field. If the purpose of the solenoid is instead to changes in the electric current. Not all electromagnets and inductors are solenoids, for example, the first electromagnet, in engineering, the term may also refer to a variety of transducer devices that convert energy into linear motion. Solenoid bolts, a type of locking mechanism, also exist. An infinite solenoid is a solenoid with infinite length but finite diameter, in short, the magnetic field inside an infinitely long solenoid is homogeneous and its strength neither depends on the distance from the axis, nor on the solenoids cross-sectional area. This is a derivation of the flux density around a solenoid that is long enough so that fringe effects can be ignored. In Figure 1, we know that the flux density vector points in the positive z direction inside the solenoid. We confirm this by applying the right hand rule for the field around a wire. If we wrap our right hand around a wire with the thumb pointing in the direction of the current, since we are dealing with a long solenoid, all of the components of the magnetic field not pointing upwards cancel out by symmetry. Outside, a similar cancellation occurs, and the field is pointing downwards. Now consider the imaginary loop c that is located inside the solenoid, by Ampères law, we know that the line integral of B around this loop is zero, since it encloses no electrical currents. We have shown above that the field is pointing upwards inside the solenoid, thus the integral of the up side 1 is equal to the integral of the down side 2. Note, though, that prohibits it from varying longitudinally. A similar argument can be applied to the loop a to conclude that the field outside the solenoid is radially uniform or constant, an intuitive argument can also be used to show that the flux density outside the solenoid is actually zero. Magnetic field lines only exist as loops, they diverge from or converge to a point like electric field lines can. The magnetic field lines follow the path of the solenoid inside. However, the volume outside the solenoid is much greater than the volume inside, now recall that the field outside is constant
23.
Glyph
–
In typography, a glyph /ˈɡlɪf/ is an elemental symbol within an agreed set of symbols, intended to represent a readable character for the purposes of writing. In Turkish, however, it is not a glyph because that language has two versions of the letter i, with and without a dot. In Japanese syllabaries, a number of the characters are made up of more than one separate mark, however, in some cases, additional marks fulfill the role of diacritics, to differentiate distinct characters. In general, a diacritic is a glyph, even if it is contiguous with the rest of the character, two or more glyphs which have the same significance, whether used interchangeably or chosen depending on context, are called allographs of each other. The term has been used in English since 1727, borrowed from glyphe, from the Greek γλυφή, glyphē, carving, and the verb γλύφειν, glýphein, to hollow out, engrave, carve. The word glyph first came to widespread European attention with the engravings, in archaeology, a glyph is a carved or inscribed symbol. It may be a pictogram or ideogram, or part of a system such as a syllable. In 1897 Dana Evans discovered glyphs written on rocks in the Colorado Desert and these ancient characters have been called the most enlightening discovery in Native American History in the 19th Century. In typography, a glyph has a different definition, it is the specific shape, design. The same is true in computing, in computing as well as typography, the term character refers to a grapheme or grapheme-like unit of text, as found in natural language writing systems. The range of glyphs required increases correspondingly, in summary, in typography and computing, a glyph is a graphical unit. In graphonomics, the glyph is used for a noncharacter. Most typographic glyphs originate from the characters of a typeface, in the mobile text input technologies, Glyph is a family of text input methods based on the decomposition of letters into basic shapes. In role-playing games, the glyph is sometimes used alongside the word rune in describing magical drawings or etchings. Runes often refer to placing the image on an object or person to empower it, whereas the magic in a glyph lies dormant and is only triggered when the glyph is read or approached
24.
ASCII
–
ASCII, abbreviated from American Standard Code for Information Interchange, is a character encoding standard. ASCII codes represent text in computers, telecommunications equipment, and other devices, most modern character-encoding schemes are based on ASCII, although they support many additional characters. ASCII was developed from telegraph code and its first commercial use was as a seven-bit teleprinter code promoted by Bell data services. Work on the ASCII standard began on October 6,1960, the first edition of the standard was published in 1963, underwent a major revision during 1967, and experienced its most recent update during 1986. Compared to earlier telegraph codes, the proposed Bell code and ASCII were both ordered for more convenient sorting of lists, and added features for other than teleprinters. Originally based on the English alphabet, ASCII encodes 128 specified characters into seven-bit integers as shown by the ASCII chart above. The characters encoded are numbers 0 to 9, lowercase letters a to z, uppercase letters A to Z, basic punctuation symbols, control codes that originated with Teletype machines, for example, lowercase j would become binary 1101010 and decimal 106. ASCII includes definitions for 128 characters,33 are non-printing control characters that affect how text and space are processed and 95 printable characters, of these, the IANA encourages use of the name US-ASCII for Internet uses of ASCII. The ASA became the United States of America Standards Institute and ultimately the American National Standards Institute, there was some debate at the time whether there should be more control characters rather than the lowercase alphabet. The X3.2.4 task group voted its approval for the change to ASCII at its May 1963 meeting, the X3 committee made other changes, including other new characters, renaming some control characters and moving or removing others. ASCII was subsequently updated as USAS X3. 4-1967, then USAS X3. 4-1968, ANSI X3. 4-1977 and they proposed a 9-track standard for magnetic tape, and attempted to deal with some punched card formats. The X3.2 subcommittee designed ASCII based on the earlier teleprinter encoding systems, like other character encodings, ASCII specifies a correspondence between digital bit patterns and character symbols. This allows digital devices to communicate each other and to process, store. Before ASCII was developed, the encodings in use included 26 alphabetic characters,10 numerical digits, ITA2 were in turn based on the 5-bit telegraph code Émile Baudot invented in 1870 and patented in 1874. The committee debated the possibility of a function, which would allow more than 64 codes to be represented by a six-bit code. In a shifted code, some character codes determine choices between options for the character codes. It allows compact encoding, but is reliable for data transmission. The standards committee decided against shifting, and so ASCII required at least a seven-bit code, the committee considered an eight-bit code, since eight bits would allow two four-bit patterns to efficiently encode two digits with binary-coded decimal
25.
Serial port
–
In computing, a serial port is a serial communication interface through which information transfers in or out one bit at a time. Throughout most of the history of computers, data was transferred through serial ports to devices such as modems, terminals. Modern computers without serial ports may require serial-to-USB converters to allow compatibility with RS-232 serial devices, serial ports are still used in applications such as industrial automation systems, scientific instruments, point of sale systems and some industrial and consumer products. Server computers may use a port as a control console for diagnostics. Network equipment often use serial console for configuration, serial ports are still used in these areas as they are simple, cheap and their console functions are highly standardized and widespread. A serial port requires very little supporting software from the host system, some computers, such as the IBM PC, use an integrated circuit called a UART. This IC converts characters to and from asynchronous serial form, implementing the timing and framing of data in hardware, very low-cost systems, such as some early home computers, would instead use the CPU to send the data through an output pin, using the bit-banging technique. Early home computers often had proprietary serial ports with pinouts and voltage levels incompatible with RS-232, low-cost processors now allow higher-speed, but more complex, serial communication standards such as USB and FireWire to replace RS-232. These make it possible to connect devices that would not have operated feasibly over slower serial connections, such as storage, sound. Many personal computer motherboards still have at least one serial port, small-form-factor systems and laptops may omit RS-232 connector ports to conserve space, but the electronics are still there. RS-232 has been standard for so long that the circuits needed to control a serial port became very cheap and often exist on a single chip, sometimes also with circuitry for a parallel port. The individual signals on a serial port are unidirectional and when connecting two devices the outputs of one device must be connected to the inputs of the other, devices are divided into two categories data terminal equipment and data circuit-terminating equipment. A line that is an output on a DTE device is an input on a DCE device and vice versa so a DCE device can be connected to a DTE device with a straight wired cable, conventionally, computers and terminals are DTE while modems and peripherals are DCE. If it is necessary to connect two DTE devices a cross-over null modem, in the form of either an adapter or a cable, generally, serial port connectors are gendered, only allowing connectors to mate with a connector of the opposite gender. With D-subminiature connectors, the male connectors have protruding pins, either type of connector can be mounted on equipment or a panel, or terminate a cable. Connectors mounted on DTE are likely to be male, and those mounted on DCE are likely to be female, however, this is far from universal, for instance, most serial printers have a female DB25 connector, but they are DTEs. The desire to supply serial interface cards with two ports required that IBM reduce the size of the connector to fit onto a single card back panel, a DE-9 connector also fits onto a card with a second DB-25 connector. Starting around the time of the introduction of the IBM PC-AT, serial ports were built with a 9-pin connector to save cost
26.
Amphenol
–
Amphenol Corporation is a major producer of electronic and fiber optic connectors, cable and interconnect systems such as coaxial cables. Amphenol is a portmanteau from the original name, American Phenolic Corp. Amphenol was founded in Chicago in 1932 by entrepreneur Arthur J. Schmitt, Amphenol expanded significantly during World War II, when the company became the primary manufacturer of connectors used in military hardware, including airplanes and radios. From 1967 to 1982 it was part of Bunker Ramo Corporation, Amphenols revenues in 2010 were $3.55 billion. Operations are located in more than 60 locations around the world, the company is included in the S&P Midcap 400 index. Amphenols Chairman is Dr. Martin H. Loeffler, Amphenols world headquarters is located in Wallingford, Connecticut. The largest division of Amphenol is Amphenol Aerospace in Sidney, New York and this is the birthplace of the MIL-DTL-38999 cylindrical connector. Amphenol engineers also invented the commonly used BNC connector, Amphenol Fiber Systems International is a fiber optic company started in 1993 that specializes in the fabrication and manufacturing of fiber optic connectivity products and systems. AFSI provides solutions for systems based on fiber optic interconnect technology. AFSI employs over 100 people at its 50,000 square foot facility in the heart of the corridor in Allen. Amphenol Cables on Demand, another division of Amphenol launched in December 2006 and they sell more than 2500 audio, video, computer, and networking cables. Offices are located in New York, California, Florida, Toronto, in May 2005, Amphenol acquired SV Microwave, a manufacturer of RF connectors, components and cable assemblies. On October 10,2005, Teradyne and Amphenol announced that Amphenol would acquire Teradyne Connection Systems, TCS, based in Nashua, New Hampshire, manufactures high-density electronic connectors, complete backplanes, and systems packaging, a product line that complements Amphenols existing lines of business. In February 2008, Amphenol acquired SEFEE, a French electronic manufacturer, Jaybeam Wireless became Amphenol Jaybeam and is now Amphenol Antenna Solutions. On November 15,2013, Amphenol announced it had entered an agreement to acquire Advanced Sensors Business of GE for approx. On January 8,2016, Amphenol finalized its deal to acquire FCI Asia Pte Ltd an interconnect company specializing in the telecom, datacom, in July 2016, Amphenol acquired AUXELFTG, a French manufacturer of power busbars and power interconnect solutions. Notes Official website Amphenol SEC Filings Amphenol LTW - Innovation in Waterproof Solution Amphenol Aerospace Amphenol Cables on Demand Amphenol RF
27.
NCR Corporation
–
They also provide IT maintenance support services. NCR had been based in Dayton, Ohio, starting in 1884, NCR was founded in 1884 and acquired by AT&T in 1991. A restructuring of AT&T in 1996 led to NCRs re-establishment January 1,1997 as a separate company, NCR is the only AT&T spin-off company that has retained its original name—all the others have either been purchased or renamed following subsequent mergers. The company began as the National Manufacturing Company of Dayton, Ohio, was established to manufacture, in 1884, the company and patents were bought by John Henry Patterson and his brother Frank Jefferson Patterson, and the firm was renamed the National Cash Register Company. Patterson formed NCR into one of the first modern American companies by introducing new, aggressive sales methods and he established the first sales training school in 1893 and introduced a comprehensive social welfare program for his factory workers. Other significant figures in the history of the company were Charles F. Kettering, Thomas J. Watson, Sr. Deeds and Kettering went on to found Dayton Engineering Laboratories Company which later became Delco Products Division of General Motors, Watson eventually worked his way up to general sales manager. At an uninspiring sales meeting, Watson interrupted, saying The trouble with one of us is that we dont think enough. We dont get paid for working with our feet — we get paid for working with our heads, Watson then wrote THINK on the easel. Signs with this motto were erected in factory buildings, sales offices, THINK later became a widely known symbol of IBM. Kettering designed the first cash register powered by a motor in 1906. Within a few years he developed the Class 1000 register which was in production for 40 years, telephone Credit Authorization system for verifying credit in department stores. When John H. Patterson and his brother took over the company, cash registers were expensive, there was little demand for the expensive device, but Patterson believed the product would sell once shopkeepers understood it would drastically decrease theft by salesclerks. He created a team known as the American Selling Force which worked on commissions and followed a standard sales script. The philosophy was to sell a business rather than just a piece of machinery. Sales demonstrations were set up in hotels depicting a store interior complete with real merchandise, the sale prospect was described as the P. P. or Probable Purchaser. Once initial objections were swept aside and the P. P. admitted to internal theft losses, the deal was sealed with a 25 cent cigar. NCR expanded quickly and became multi-national in 1888, between 1893 and 1906 it acquired a number of smaller cash register companies
28.
VAX
–
VAX is a discontinued instruction set architecture developed by Digital Equipment Corporation in the mid-1970s. The VAX-11/780, introduced on October 25,1977, was the first of a range of popular, a 32-bit system with a CISC architecture based on DECs earlier PDP-11, VAX was designed to extend or replace DECs various PDP ISAs. The VAX architectures primary features were virtual addressing and its instruction set. Later versions offloaded the compatibility mode and some of the less used CISC instructions to emulation in the system software. The VAX instruction set was designed to be powerful and orthogonal, when it was introduced, many programs were written in assembly language, so having a programmer-friendly instruction set was important. In time, as programs were written in higher-level language, the instruction set became less visible. One unusual aspect of the VAX instruction set is the presence of register masks at the start of each subprogram and these are arbitrary bit patterns that specify, when control is passed to the subprogram, which registers are to be preserved. Since register masks are a form of data embedded within the executable code and this can complicate optimization techniques that are applied on machine code. The native VAX operating system is Digitals VAX/VMS, the VAX architecture and OpenVMS operating system were engineered concurrently to take maximum advantage of each other, as was the initial implementation of the VAXcluster facility. Other VAX operating systems have included various releases of BSD UNIX up to 4. 3BSD, Ultrix-32, VAXELN, more recently, NetBSD and OpenBSD support various VAX models and some work has been done on porting Linux to the VAX architecture. The first VAX model sold was the VAX-11/780, which was introduced on October 25,1977 at the Digital Equipment Corporations Annual Meeting of Shareholders, bill Strecker, C. Gordon Bells doctoral student at Carnegie Mellon University, was responsible for the architecture. Many different models with different prices, performance levels, and capacities were subsequently created, VAX superminicomputers were very popular in the early 1980s. For a while the VAX-11/780 was used as a standard in CPU benchmarks, the actual number of instructions executed in 1 second was about 500,000, which led to complaints of marketing exaggeration. The result was the definition of a VAX MIPS, the speed of a VAX-11/780, within the Digital community the term VUP was the more common term, because MIPS do not compare well across different architectures. The related term cluster VUPs was informally used to describe the performance of a VAXcluster. The VAX-11/780 included a subordinate stand-alone LSI-11 computer that performed microcode load, booting and this was dropped from subsequent VAX models. Enterprising VAX-11/780 users could therefore run three different Digital Equipment Corporation operating systems, VMS on the VAX processor, and either RSX-11M or RT-11 on the LSI-11, the VAX went through many different implementations. The original VAX 11/780 was implemented in TTL and filled a cabinet with a single CPU
29.
DC-37
–
The D-subminiature or D-sub is a common type of electrical connector. They are named for their characteristic D-shaped metal shield, when they were introduced, D-subs were among the smallest connectors used on computer systems. The part containing pin contacts is called the male connector or plug, the sockets shield fits tightly inside the plugs shield. Panel mounted connectors usually have threaded nuts that accept screws on the cable end connector cover that are used for locking the connectors together, occasionally the nuts may be found on a cable end connector if it is expected to connect to another cable end. When screened cables are used, the shields are connected to the screens of the cables. This creates a continuous screen covering the whole cable and connector system. The D-sub series of connectors was introduced by Cannon in 1952, each shell size usually corresponds to a certain number of pins or sockets, A with 15, B with 25, C with 37, D with 50, and E with 9. For example, DB-25 denotes a D-sub with a 25-position shell size and this spacing is called normal density. The suffixes M and F are sometimes used instead of the original P and S for plug, later D-sub connectors added extra pins to the original shell sizes, and their names follow the same pattern. For example, the DE-15, usually found in VGA cables, has 15 pins in three rows, all surrounded by an E size shell, the pins are spaced at 0.090 inches horizontally and 0.078 inches vertically, in what is called high density. The other connectors with the pin spacing are the DA-26, DB-44, DC-62, DD-78. They all have three rows of pins, except the DD-78 which has four, and the DF-104 which has five rows in a new, the double density series of D-sub connectors features even denser arrangements and consists of the DE-19, DA-31, DB-52, DC-79, and DD-100. These each have three rows of pins, except the DD-100, which has four, however, this naming pattern is not always followed. It is now common to see DE-9 connectors sold as DB-9 connectors, DB-9 nearly always refers to a 9-pin connector with an E size shell. Cannon also produced combo D-subs with larger contacts in place of some of the contacts, for use for high-current, high-voltage. The DB-13W3 variant was used for high-performance video connections, this variant provided 10 regular pins plus three coaxial contacts for the red, green, and blue video signals. Some variants have current ratings up to 40 A or operating voltages as high as 13,500 V, others are waterproof, a smaller type of connector derived from the D-sub is called the microminiature D, or micro-D, which is a trademark of ITT Cannon. It is about half the length of a D-sub, a further family of connectors of similar appearance to the D-sub family uses names such as HD-50 and HD-68, and has a D-shaped shell about half the width of a DB25
30.
Texas Instruments
–
Texas Instruments Inc. is an American technology company that designs and manufactures semiconductors, which it sells to electronics designers and manufacturers globally. Headquartered in Dallas, Texas, United States, TI is one of the top ten semiconductor companies worldwide, Texas Instrumentss focus is on developing analog chips and embedded processors, which accounts for more than 85% of their revenue. TI also produces TI digital light processing technology and education technology products including calculators, microcontrollers, to date, TI has more than 43,000 patents worldwide. TI produced the worlds first commercial silicon transistor in 1950, Jack Kilby invented the integrated circuit in 1958 while working at TIs Central Research Labs. TI also invented the hand-held calculator in 1967, and introduced the first single-chip microcontroller in 1970, in 1987, TI invented the digital light processing device, which serves as the foundation for the companys award-winning DLP technology and DLP Cinema. In 1990, TI came out with the popular TI-81 calculator which made them a leader in the calculator industry. In 1997, its business was sold to Raytheon, which allowed TI to strengthen its focus on digital solutions. Texas Instruments was founded by Cecil H. Green, J. Erik Jonsson, Eugene McDermott, McDermott was one of the original founders of Geophysical Service Inc. in 1930. McDermott, Green, and Jonsson were GSI employees who purchased the company in 1941, in November,1945, Patrick Haggerty was hired as general manager of the Laboratory and Manufacturing division, which focused on electronic equipment. By 1951, the L&M division, with its contracts, was growing faster than GSIs Geophysical division. The company was reorganized and initially renamed General Instruments Inc, because there already existed a firm named General Instrument, the company was renamed Texas Instruments that same year. From 1956 to 1961, Fred Agnich of Dallas, later a Republican member of the Texas House of Representatives, was the Texas Instruments president, Geophysical Service, Inc. became a subsidiary of Texas Instruments. Early in 1988 most of GSI was sold to the Halliburton Company, in 1930, J. Clarence Karcher and Eugene McDermott founded Geophysical Service, an early provider of seismic exploration services to the petroleum industry. In 1939, the company reorganized as Coronado Corp. an oil company with Geophysical Service Inc, on December 6,1941, McDermott along with three other GSI employees, J. Erik Jonsson, Cecil H. Green, and H. B. During World War II, GSI expanded their services to include electronics for the U. S. Army, Signal Corps, in 1951, the company changed its name to Texas Instruments, GSI becoming a wholly owned subsidiary of the new company. Texas Instruments also continued to manufacture equipment for use in the seismic industry, after selling GSI, TI finally sold the company to Halliburton in 1988, at which point GSI ceased to exist as a separate entity. Texas Instruments entered the electronics market in 1942 with submarine detection equipment. During the early 1980s, Texas Instruments instituted a quality program which included Juran training, as well as promoting statistical process control, Taguchi methods and Design for Six Sigma
31.
Edge connector
–
An edge connector is the portion of a printed circuit board consisting of traces leading to the edge of the board that are intended to plug into a matching socket. The edge connector is a device because it only requires a single discrete female connector. They are commonly used in computers for expansion slots for cards, such as PCI, PCI Express. Edge connector sockets consist of a plastic box open on one side, connectors are often keyed to ensure the correct polarity, and may contain bumps or notches both for polarity and to ensure that the wrong type of device is not inserted. The sockets width is chosen to fit to the thickness of the connecting PCB, the opposite side of the socket is often an insulation-piercing connector which is clamped onto a ribbon cable. Alternatively, the side may be soldered to a motherboard or daughtercard. Edge connectors are used in personal computers for connecting expansion cards. Example expansion peripheral technologies which use edge connectors include PCI, PCI Express, Slot 1 and Slot A also used edge connectors, the processor being mounted on a card with an edge connector, instead of directly to the motherboard as before and since. IBM PCs used edge connector sockets attached to cables to connect 5.25 floppy disk drives. 3.5 drives use a pin connector instead, video game cartridges typically take the form of a PCB with an edge connector, the socket is located within the console itself
32.
Data General
–
Data General was one of the first minicomputer firms from the late 1960s. Three of the four founders were former employees of Digital Equipment Corporation and their first product, the Data General Nova, was a 16-bit minicomputer. The Nova was followed by the Supernova and Eclipse product lines, the company employed an original equipment manufacturer sales strategy to sell to third parties who incorporated Data General computers into the OEMs specific product lines. The company did continue into the 1990s, however, and was acquired by EMC Corporation in 2002. Data General was founded by engineers from Digital Equipment Corporation who were frustrated with DECs management. The chief founders were Edson de Castro, Henry Burkhardt III, and Richard Sogge of Digital Equipment, the company was founded in Hudson, Massachusetts in 1968. Edson de Castro was the engineer in charge of the PDP-8. It was designed specifically to be used in laboratory equipment settings, as the technology improved, many PDP-8s still operated decades later. De Castro, convinced he could do one better, began work on his new 16-bit design, the result was released in 1969 as the Nova. Designed to be rack-mounted similarly to the later PDP-8 machines, it was smaller in height, with the initial success of the Nova, Data General went public in the fall of 1969. The Nova, like the PDP-8, used a simple accumulator-based architecture, the original Nova was soon followed by the faster SuperNova, then later by several minor versions based on the SuperNova core. The last major version, the Nova 4, was released in 1978, during this period the Nova generated 20% annual growth rates for the company, becoming a star in the business community and generating US$100 million in sales in 1975. In 1977, DG launched a 16-bit microcomputer called the microNOVA to poor commercial success, the Nova series plays a very important role as instruction-set inspiration to Charles P. Thacker and others at Xerox PARC during their construction of the Xerox Alto. In 1974, the Nova was supplanted by their upscale 16-bit machine, based on many of the same concepts as the Nova, it included support for virtual memory and multitasking more suitable to the small office environment. For this reason, the Eclipse was packaged differently, in a case resembling a small refrigerator. Production problems with the Eclipse led to a rash of lawsuits in the late 1970s, newer versions of the machine were pre-ordered by many of DGs customers, which were never delivered. Many customers sued Data General after more than a year of waiting, charging the company with breach of contract, while others simply canceled their orders and went elsewhere. Strong demand continued for the Nova series, resulting in the Nova 4, in 1976, Digital announced the VAX series, their first 32-bit minicomputer line, described as super-minis
33.
IBM Personal Computer
–
The IBM Personal Computer, commonly known as the IBM PC, is the original version and progenitor of the IBM PC compatible hardware platform. It is IBM model number 5150, and was introduced on August 12,1981 and it was created by a team of engineers and designers under the direction of Don Estridge of the IBM Entry Systems Division in Boca Raton, Florida. IBM compatible became an important criterion for sales growth, only the Apple Macintosh family kept significant market share without compatibility with the IBM personal computer, International Business Machines, one of the worlds largest companies, had a 62% share of the mainframe computer market in 1981. Its share of the computer market, however, had declined from 60% in 1970 to 32% in 1980. In 1979 BusinessWeek asked, Is IBM just another stodgy, mature company, by 1981 its stock price had declined by 22%. IBMs earnings for the first half the year grew by 5. 3%—one third of the inflation rate—while those of minicomputer maker Digital Equipment Corporation grew by more than 35%. B. M, No longer dominates the computer business. IBM wished to avoid the outcome with the new personal computer industry, dominated by the Commodore PET, Atari 8-bit family, Apple II, Tandy Corporations TRS-80. With $150 million in sales by 1979 and projected growth of more than 40% in the early 1980s. The Japanese project, codenamed Go, ended before the 1981 release of the American-designed IBM PC codenamed Chess, whether IBM had waited too long to enter an industry in which Apple and others were already successful was unclear. An observer stated that IBM bringing out a computer would be like teaching an elephant to tap dance. Successful microcomputer company Vector Graphics fiscal 1980 revenue was $12 million, the company only sold through its internal sales force, had no experience with resellers or retail stores, and did not introduce the first product designed to work with non-IBM equipment until 1980. Another observer claimed that IBM made decisions so slowly that, when tested, as with other large computer companies, its new products typically required about four to five years for development. IBM had to learn how to develop, mass-produce. The potential importance to microcomputers of a company so prestigious, that a saying in American companies stated No one ever got fired for buying IBM, was nonetheless clear. InfoWorld, which described itself as The Newsweekly for Microcomputer Users, stated that for my grandmother, is far and away the media star, not because of its features, but because it exists at all. When the number eight company in the Fortune 500 enters the field, the influence of a personal computer made by a company whose name has literally come to mean computer to most of the world is hard to contemplate. The editorial acknowledged that some factions in our industry have looked upon IBM as the enemy, desktop sized programmable calculators by Hewlett Packard had evolved into the HP9830 BASIC language computer by 1972. In 1972–1973 a team led by Dr. SCAMP emulated an IBM1130 minicomputer to run APL\1130, in 1973 APL was generally available only on mainframe computers, and most desktop sized microcomputers such as the Wang 2200 or HP9800 offered only BASIC
34.
DB-25F
–
The D-subminiature or D-sub is a common type of electrical connector. They are named for their characteristic D-shaped metal shield, when they were introduced, D-subs were among the smallest connectors used on computer systems. The part containing pin contacts is called the male connector or plug, the sockets shield fits tightly inside the plugs shield. Panel mounted connectors usually have threaded nuts that accept screws on the cable end connector cover that are used for locking the connectors together, occasionally the nuts may be found on a cable end connector if it is expected to connect to another cable end. When screened cables are used, the shields are connected to the screens of the cables. This creates a continuous screen covering the whole cable and connector system. The D-sub series of connectors was introduced by Cannon in 1952, each shell size usually corresponds to a certain number of pins or sockets, A with 15, B with 25, C with 37, D with 50, and E with 9. For example, DB-25 denotes a D-sub with a 25-position shell size and this spacing is called normal density. The suffixes M and F are sometimes used instead of the original P and S for plug, later D-sub connectors added extra pins to the original shell sizes, and their names follow the same pattern. For example, the DE-15, usually found in VGA cables, has 15 pins in three rows, all surrounded by an E size shell, the pins are spaced at 0.090 inches horizontally and 0.078 inches vertically, in what is called high density. The other connectors with the pin spacing are the DA-26, DB-44, DC-62, DD-78. They all have three rows of pins, except the DD-78 which has four, and the DF-104 which has five rows in a new, the double density series of D-sub connectors features even denser arrangements and consists of the DE-19, DA-31, DB-52, DC-79, and DD-100. These each have three rows of pins, except the DD-100, which has four, however, this naming pattern is not always followed. It is now common to see DE-9 connectors sold as DB-9 connectors, DB-9 nearly always refers to a 9-pin connector with an E size shell. Cannon also produced combo D-subs with larger contacts in place of some of the contacts, for use for high-current, high-voltage. The DB-13W3 variant was used for high-performance video connections, this variant provided 10 regular pins plus three coaxial contacts for the red, green, and blue video signals. Some variants have current ratings up to 40 A or operating voltages as high as 13,500 V, others are waterproof, a smaller type of connector derived from the D-sub is called the microminiature D, or micro-D, which is a trademark of ITT Cannon. It is about half the length of a D-sub, a further family of connectors of similar appearance to the D-sub family uses names such as HD-50 and HD-68, and has a D-shaped shell about half the width of a DB25
35.
Seiko Epson
–
Seiko Epson Corporation, or simply Epson, is a Japanese electronics company and one of the worlds largest manufacturers of computer printers, and information and imaging related equipment. It is one of three companies of the Seiko Group, a name traditionally known for manufacturing Seiko timepieces since its founding. In 1968 the company moved its UK headquarters to Audenshaw, Manchester, after acquiring the Jones Sewing Machine Company, Daiwa Kogyo was supported by an investment from the Hattori family and began as a manufacturer of watch parts for Daini Seikosha. The company started operation in a 2, 500-square-foot renovated miso storehouse with 22 employees, in 1943, Daini Seikosha established a factory in Suwa for manufacturing Seiko watches with Daiwa Kogyo. In 1959, the Suwa Factory of Daini Seikosha was split up, Ltd, the forerunner of the Seiko Epson Corporation. The company has developed many timepiece technologies, the watches made by the company are sold through the Seiko Watch Corporation, a subsidiary of Seiko Holdings Corporation. In 1961, Suwa Seikosha established a company called Shinshu Seiki Co. as a subsidiary to supply parts for Seiko watches. In September 1968, Shinshu Seiki launched the worlds first mini-printer, in June 1975, the name Epson was coined for the next generation of printers based on the EP-101 which was released to the public. In April of the same year Epson America Inc. was established to sell printers for Shinshu Seiki Co, in June 1978, the TX-80, eighty-column dot-matrix printer was released to the market, and was mainly used as a system printer for the Commodore PET Computer. After two years of development, an improved model, the MX-80, was launched in October 1980. It was soon described in the companys advertising as the best selling printer in the United States, in November 1985, Suwa Seikosha Co. Ltd. and the Epson Corporation merged to form Seiko Epson Corporation. Shortly after in 1994, Epson released the first high resolution color inkjet printer, newer models of the Stylus series employed Epson’s special DURABrite ink. They also had two hard drives, the HD850 and the HD860 MFM interface. The specifications are reference The WINN L. ROSCH Hardware bible 3rd addition SAMS publishing, in 1994 Epson started outsourcing sales reps to help sell their products in retail stores in the United States. In 1994 Epson started the Epson Weekend Warrior sales program, the purpose of the program was to help improve sales, improve retail sales reps knowledge of Epson products and to address Epson customer service in a retail environment. Reps were assigned on weekend shift, typically around 12–20 hours a week, Epson started the Weekend Warrior program with TMG Marketing, later with Keystone Marketing Inc, then to Mosaic, and now with Campaigners INC. The Mosaic contract expired with Epson on June 24,2007 and Epson is now represented by Campaigners, the sales reps of Campaigners, Inc. are not outsourced as Epson hired rack jobbers to ensure their retail customers displayed products properly. This frees up their regular sales force to concentrate on profitable sales solutions to VARs and system integrators, in June 2003, the company became public following their listing on the 1st section of the Tokyo Stock Exchange
36.
IBM Personal System/2
–
The Personal System/2 or PS/2 was IBMs third generation of personal computers. Released in 1987, it replaced the IBM PC, XT, AT. The PS/2 line was created by IBM in an attempt to control of the PC market by introducing an advanced yet proprietary architecture. IBMs considerable market presence plus the reliability of the PS/2 ensured that the systems would sell in large numbers. Also the evolving Wintel architecture was seeing a period of dramatic reductions in price, the OS/2 operating system was announced at the same time as the PS/2 line and was intended to be the primary operating system for models with Intel 286 or later processors. However, at the time of the first shipments, only PC DOS was available, OS/21.0 and Microsofts Windows 2.0 became available several months later. IBM also released AIX PS/2, a UNIX operating system for PS/2 models with Intel 386 or later processors, for years before IBM released the PS/2, rumors spread about IBMs plans for successors to its IBM PC, XT, and AT personal computers. Among the rumors that did not come true, The company would use proprietary, the company would release a version of its VM mainframe operating system for them. The company would design the new computers to make third-party communications products more difficult to design, IBMs PS/2 was designed to remain software compatible with their PC/AT/XT line of computers upon which the large PC clone market was built, but the hardware was quite different. CBIOS was so compatible that it even included Cassette BASIC, while IBM did not publish the BIOS source code, it did promise to publish BIOS entry points. With the IBM PS/2 line, Micro Channel Architecture was also introduced, MCA was conceptually similar to the channel architecture of the IBM System/360 mainframes. MCA was technically superior to ISA and allowed for higher speed communications within the system, MCA featured many advances not seen in other standards until several years later. Transfer speeds were on par with the much later PCI standard, MCA allowed one-to-one, card to card, and multi-card to processor simultaneous transaction management which is a feature of the PCI-X bus format. Bus mastering capability, bus arbitration, and a form of plug-and-play BIOS management of hardware were all benefits of MCA. (One book from the year 2000 writes, MCA used a version of what we know now as “Plug-N′-Play”, requiring a special setup disk for each machine. MCA never gained wide acceptance outside of the PS/2 line due to IBMs anti-clone practices and incompatibilities with ISA, IBM offered to sell an MCA license to anyone who could afford the royalty. However, royalties were required for every MCA-compatible machine sold and a payment for every IBM-compatible machine the particular maker had made in the past, there was nothing unique in IBM insisting on payment of royalties on the use of its patents applied to Micro Channel based machines. However, up until that time, some companies had failed to pay IBM for the use of its patents on the generation of Personal Computer
37.
Hewlett-Packard
–
The Hewlett-Packard Company or shortened to Hewlett-Packard was an American multinational information technology company headquartered in Palo Alto, California. The company was founded in a garage in Palo Alto by William Bill Redington Hewlett and David Dave Packard. HP was the worlds leading PC manufacturer from 2007 to Q22013 and it specialized in developing and manufacturing computing, data storage, and networking hardware, designing software and delivering services. HP also had services and consulting business around its products and partner products.4 billion in 2008, in November 2009, HP announced the acquisition of 3Com, with the deal closing on April 12,2010. On April 28,2010, HP announced the buyout of Palm, on September 2,2010, HP won its bidding war for 3PAR with a $33 a share offer, which Dell declined to match. On October 6,2014, Hewlett-Packard announced plans to split the PC and printers business from its enterprise products, the split closed on November 1,2015, and resulted in two publicly traded companies, HP Inc. and Hewlett Packard Enterprise. William Redington Hewlett and David Packard graduated with degrees in engineering from Stanford University in 1935. The company originated in a garage in nearby Palo Alto during a fellowship they had with a past professor, Terman was considered a mentor to them in forming Hewlett-Packard. In 1939, Packard and Hewlett established Hewlett-Packard in Packards garage with a capital investment of US$538. Hewlett and Packard tossed a coin to decide whether the company they founded would be called Hewlett-Packard or Packard-Hewlett, HP incorporated on August 18,1947, and went public on November 6,1957. Of the many projects they worked on, their very first financially successful product was an audio oscillator. This allowed them to sell the Model 200A for $54.40 when competitors were selling less stable oscillators for over $200, the Model 200 series of generators continued until at least 1972 as the 200AB, still tube-based but improved in design through the years. They worked on technology and artillery shell fuses during World War II. Hewlett-Packards HP Associates division, established around 1960, developed semiconductor devices primarily for internal use, instruments and calculators were some of the products using these devices. HP partnered in the 1960s with Sony and the Yokogawa Electric companies in Japan to develop several high-quality products, the products were not a huge success, as there were high costs in building HP-looking products in Japan. HP and Yokogawa formed a joint venture in 1963 to market HP products in Japan, HP bought Yokogawa Electrics share of Hewlett-Packard Japan in 1999. HP spun off a company, Dynac, to specialize in digital equipment. The name was picked so that the HP logo hp could be turned upside down to be a reverse image of the logo dy of the new company
38.
HP LaserJet 4
–
The HP LaserJet 4 is a group of monochrome laser printers produced in the early to mid-1990s as part of the LaserJet series by Hewlett Packard. The 4 series has various models, including the standard LaserJet 4 for business use, the 4L for personal use, additional models included the 4Si model, created as a heavy-duty business printer, and the 4V model, a B-size printer for desktop publishing and graphic artists. There are also PostScript variants of these machines with the 4M designation, where M stands for, Hewlett Packard also released an upgraded version of the LaserJet 4/4M known as the 4 Plus /4M Plus. The LaserJet 4 series was discontinued in the 1990s, and Hewlett Packard recommended the HP LaserJet 5 series as a replacement for the 4 series. However the driver for the HP LaserJet 4 exists in most, even older, a feature of the 4+, and 4Si particularly dear to graphic designers was the straight paper feed. Unusually thick paper could be run through the printers without jamming by setting the output tray to Lower, similar models of earlier HP laser printers had this feature, but it became less common with the later models. The EX print engine is known for its reliability and longevity, and in comparison to earlier generations of laser printers, the engine has a high monthly duty cycle and it is not uncommon to find units still functioning well after a million or more page impressions. However, any printer mechanism is subject to wear and degeneration, printers that exhibit the accordion or washboard paper jam problem with the paper tightly concertinad or folded in the exit paper path generally have problems with the paper exit mechanism. In many cases, the rollers in the upper or final stage of the paper exit are worn or unserviceable. Replacement kits for these rollers are easily obtainable and can solve the problem, an alternative is to enlarge the roller slightly by using heat shrink over the output rollers. The heat shrink extra diameter pulls the paper quicker and resolves the wear/slip issues, another alternative is to use coarse quality abrasive paper such as those used by belt sanders to roughen the surfaces of the rollers. A quality abrasive is needed to ensure no particles are shed into the mechanism, introduced in 1992, this is the original LaserJet 4 with the Canon EX laser print engine. It prints eight pages per minute, and the user cannot extend the feeders, the LaserJet 4 Plus, released in 1994, was the LaserJet 4 with the improved Canon EX+ engine which increased printing speed to 12 PPM. This also provided the option for duplex printing with the purchase of an accessory, the original 20 MHz processor was also upgraded to 25 MHz, with the addition of Hewlett Packards Memory Enhancement Technology. The printing mechanism was improved to allow increased tones of grayscale. These models also feature a 20-30W power saving mode, which was not included in the original Laserjet 4, the 4Si were heavy-duty business printers, produced using the Canon NX engine. The 4Si worked at 17 PPM, could print on paper up to 8. 5x14, and could be upgraded with a duplexing unit and an envelope feeder. Besides the usual malfunctions common to laser printers with worn rollers or accumulated paper dust, on longer documents, the printer will stop and report a paper jam, but with no visible reason why the paper wasnt feeding correctly
39.
Nibble
–
In computing, a nibble is a four-bit aggregation, or half an octet. It is also known as half-byte or tetrade, in a networking or telecommunication context, the nibble is often called a semi-octet, quadbit, or quartet. A nibble has sixteen possible values, a nibble can be represented by a single hexadecimal digit and called a hex digit. A full byte is represented by two digits, therefore, it is common to display a byte of information as two nibbles. Sometimes the set of all 256 byte values is represented as a 16×16 table, four-bit computer architectures use groups of four bits as their fundamental unit. Such architectures were used in microprocessors, pocket calculators and pocket computers. They continue to be used in some microcontrollers, the term nibble originates from its representing half a byte, with byte a homophone of the English word bite. The alternative spelling nybble reflects the spelling of byte, as noted in editorials of Kilobaud, another early recorded use of the term nybble was in 1977 within the consumer-banking technology group at Citibank. It created a pre-ISO8583 standard for transactional messages between cash machines and Citibanks data centers that used the basic informational unit NABBLE, the nibble is used to describe the amount of memory used to store a digit of a number stored in packed decimal format within an IBM mainframe. This technique is used to make faster and debugging easier. An 8-bit byte is split in half and each nibble is used to one decimal digit. The last nibble of the variable is reserved for the sign, thus a variable which can store up to nine digits would be packed into 5 bytes. Ease of debugging resulted from the numbers being readable in a hex dump where two hex numbers are used to represent the value of a byte, as 16×16 =28, for example, a five-byte BCD value of 31415926 5C represents a decimal value of +314159265. Historically, there are cases where nybble was used for a group of bits greater than 4, in the Apple II microcomputer line, much of the disk drive control and group-coded recording was implemented in software. Writing data to a disk was done by converting 256-byte pages into sets of 5-bit nibbles, moreover,1982 documentation for the Integrated Woz Machine refers consistently to an 8 bit nibble. The term byte once had the same ambiguity and meant a set of bits but not necessarily 8, hence the distinction of bytes and octets or of nibbles and quartets. Today, the terms byte and nibble almost always refer to 8-bit and 4-bit collections respectively and are rarely used to express any other sizes. The terms semi-nibble or nibblet have occasionally used to refer to half a nibble
