1.
Computer architecture
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In computer engineering, computer architecture is a set of rules and methods that describe the functionality, organization, and implementation of computer systems. Some definitions of architecture define it as describing the capabilities and programming model of a computer, in other definitions computer architecture involves instruction set architecture design, microarchitecture design, logic design, and implementation. The first documented computer architecture was in the correspondence between Charles Babbage and Ada Lovelace, describing the analytical engine, johnson had the opportunity to write a proprietary research communication about the Stretch, an IBM-developed supercomputer for Los Alamos National Laboratory. Brooks went on to develop the IBM System/360 line of computers. Later, computer users came to use the term in many less-explicit ways, the earliest computer architectures were designed on paper and then directly built into the final hardware form. The discipline of architecture has three main subcategories, Instruction Set Architecture, or ISA. The ISA defines the code that a processor reads and acts upon as well as the word size, memory address modes, processor registers. Microarchitecture, or computer organization describes how a processor will implement the ISA. The size of a computers CPU cache for instance, is an issue that generally has nothing to do with the ISA, system Design includes all of the other hardware components within a computing system. These include, Data processing other than the CPU, such as memory access Other issues such as virtualization, multiprocessing. There are other types of computer architecture, E. g. the C, C++, or Java standards define different Programmer Visible Macroarchitecture. UISA —a group of machines with different hardware level microarchitectures may share a common microcode architecture, pin Architecture, The hardware functions that a microprocessor should provide to a hardware platform, e. g. the x86 pins A20M, FERR/IGNNE or FLUSH. Also, messages that the processor should emit so that external caches can be invalidated, pin architecture functions are more flexible than ISA functions because external hardware can adapt to new encodings, or change from a pin to a message. The term architecture fits, because the functions must be provided for compatible systems, the purpose is to design a computer that maximizes performance while keeping power consumption in check, costs low relative to the amount of expected performance, and is also very reliable. For this, many aspects are to be considered which includes Instruction Set Design, Functional Organization, Logic Design, the implementation involves Integrated Circuit Design, Packaging, Power, and Cooling. Optimization of the design requires familiarity with Compilers, Operating Systems to Logic Design, an instruction set architecture is the interface between the computers software and hardware and also can be viewed as the programmers view of the machine. Computers do not understand high level languages such as Java, C++, a processor only understands instructions encoded in some numerical fashion, usually as binary numbers. Software tools, such as compilers, translate those high level languages into instructions that the processor can understand, besides instructions, the ISA defines items in the computer that are available to a program—e. g
2.
Instruction set architecture
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An ISA includes a specification of the set of opcodes, and the native commands implemented by a particular processor. An instruction set architecture is distinguished from a microarchitecture, which is the set of design techniques used, in a particular processor. Processors with different microarchitectures can share a common instruction set, for example, the Intel Pentium and the AMD Athlon implement nearly identical versions of the x86 instruction set, but have radically different internal designs. The concept of an architecture, distinct from the design of a machine, was developed by Fred Brooks at IBM during the design phase of System/360. Prior to NPL, the companys computer designers had been free to honor cost objectives not only by selecting technologies, the SPREAD compatibility objective, in contrast, postulated a single architecture for a series of five processors spanning a wide range of cost and performance. In addition, these virtual machines execute less frequently used code paths by interpretation, transmeta implemented the x86 instruction set atop VLIW processors in this fashion. A complex instruction set computer has many specialized instructions, some of which may only be used in practical programs. Theoretically important types are the instruction set computer and the one instruction set computer. Another variation is the very long instruction word where the processor receives many instructions encoded and retrieved in one instruction word, machine language is built up from discrete statements or instructions. Examples of operations common to many instruction sets include, Set a register to a constant value. Copy data from a location to a register, or vice versa. Used to store the contents of a register, result of a computation, often called load and store operations. Read and write data from hardware devices, add, subtract, multiply, or divide the values of two registers, placing the result in a register, possibly setting one or more condition codes in a status register. Increment, decrement in some ISAs, saving operand fetch in trivial cases, perform bitwise operations, e. g. taking the conjunction and disjunction of corresponding bits in a pair of registers, taking the negation of each bit in a register. Floating-point instructions for arithmetic on floating-point numbers, branch to another location in the program and execute instructions there. Conditionally branch to another if a certain condition holds. Call another block of code, while saving the location of the instruction as a point to return to. Load/store data to and from a coprocessor, or exchanging with CPU registers, processors may include complex instructions in their instruction set
3.
Endianness
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Endianness refers to the sequential order used to numerically interpret a range of bytes in computer memory as a larger, composed word value. It also describes the order of transmission over a digital link. Little-endian format reverses the order of the sequence and stores the least significant byte at the first location with the most significant byte being stored last. The order of bits within a byte can also have endianness, however, both big and little forms of endianness are widely used in digital electronics. As examples, the IBM z/Architecture mainframes use big-endian while the Intel x86 processors use little-endian, the designers chose endianness in the 1960s and 1970s respectively. Big-endian is the most common format in data networking, fields in the protocols of the Internet protocol suite, such as IPv4, IPv6, TCP, for this reason, big-endian byte order is also referred to as network byte order. Little-endian storage is popular for microprocessors, in due to significant influence on microprocessor designs by Intel Corporation. Mixed forms also exist, for instance the ordering of bytes in a 16-bit word may differ from the ordering of 16-bit words within a 32-bit word, such cases are sometimes referred to as mixed-endian or middle-endian. There are also some bi-endian processors that operate in either little-endian or big-endian mode, big-endianness may be demonstrated by writing a decimal number, say one hundred twenty-three, on paper in the usual positional notation understood by a numerate reader,123. The digits are written starting from the left and to the right, with the most significant digit,1 and this is analogous to the lowest address of memory being used first. This is an example of a big-endian convention taken from daily life, the little-endian way of writing the same number, one hundred twenty-three, would place the hundreds-digit 1 in the right-most position,321. A person following conventional big-endian place-value order, who is not aware of this ordering, would read a different number. Endianness in computing is similar, but it applies to the ordering of bytes. The illustrations to the right, where a is a memory address, danny Cohen introduced the terms Little-Endian and Big-Endian for byte ordering in an article from 1980. Computer memory consists of a sequence of storage cells, each cell is identified in hardware and software by its memory address. If the total number of cells in memory is n. Computer programs often use data structures of fields that may consist of data than is stored in one memory cell. For the purpose of this article where its use as an operand of an instruction is relevant, in addition to that, it has to be of numeric type in some positional number system
4.
Decimal computer
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Some also had a variable wordlength, which enabled operations on numbers with a large number of digits. Early computers that were exclusively decimal include the ENIAC, IBM NORC, IBM650, IBM1620, IBM7070. In these machines the basic unit of data was the decimal digit, encoded in one of several schemes, including binary-coded decimal or BCD, bi-quinary, excess-3, except for the 1620, these machines used word addressing. When non-numeric characters were used in machines, they were encoded as two decimal digits. Other early computers were character oriented, providing instructions for performing arithmetic on character strings of decimal numerals, on these machines the basic data element was an alphanumeric character, typically encoded in six bits. UNIVAC I and UNIVAC II used word addressing, with 12-character words, IBM examples include IBM702, IBM705, the IBM1400 series, IBM7010, and the IBM7080. It used 8-bit characters and introduced EBCDIC encoding, though ASCII was also supported, several microprocessor families offer limited decimal support. For example, the 80x86 family of microprocessors provide instructions to convert one-byte BCD numbers to binary format before or after arithmetic operations and these operations were not extended to wider formats and hence are now slower than using 32-bit or wider BCD tricks to compute in BCD. The x87 FPU has instructions to convert 10-byte packed decimal data, Decimal arithmetic is now becoming more common, for instance, three decimal types with two binary encodings were added to the 2008 IEEE 754r standard, with 7-, 16-, and 34-digit decimal significands. The IBM Power6 processor and the IBM System z9 have implemented these types using the Densely Packed Decimal binary encoding, the first in hardware, binghamton, New York, USA, John Wiley & Sons, Inc. Malabar, Florida, USA, Robert E. Krieger Publishing Company, Iowa City, Iowa, USA, The University of Iowa, Department of Computer Science
5.
IBM
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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
6.
IBM 1400 series
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The IBM1400 series were second-generation mid-range business decimal computers that IBM marketed in the early 1960s. The 1400-series machines stored information in magnetic cores as variable length character strings separated at the left and right by a special flag, input and output support included punched card, magnetic tape, and high speed line printers. Many members of the series could be used as independent systems, as extensions to IBM punched card equipment, some, however, were intended for specific applications or were economical only as independent systems. The 1401 was the first member of the IBM1400 series and it was the first computer to deploy over 10,000 units. The IBM1410 was a design, but with a larger address space. The IBM1460 was logically but not physically identical to a fully optioned 1401 with 16,000 characters of memory, the 1240 was a banking system, equivalent to the 1440 system with MICR support. The IBM7010 was logically but not physically identical to a 1410, members of the 1400 series included, IBM1240 -1963 banking system. IBM1401 -1959 IBM1410 -1960 IBM1420 -1962 high-speed bank transit system, IBM1440 -1962 IBM1450 -1968 Bank Data Processing System for small banks. 1460 was twice as fast, and many features of 1401 were standard. 1440 was a popular lower-cost alternative, although not fully compatible with the 1401,1240,1420,1450 were systems specially designed for banking. 1410 was a faster system in the same spirit as 1401, but with significant differences, such as larger memory, more index registers. A remarkable feature in the era was a compatibility mode switch that allowed it to run 1401 programs without change. 7010 was a faster and exactly compatible version of 1410, the IBM System/360 Model 30 could be ordered with a 1401 compatibility microprogram feature. Several 1400 series peripherals were adapted for use with System/360, honeywells Honeywell 200 provided approximate 1401 compatibility through a combination of architectural similarity and software support. With the 1410 series, the smallest addressable unit in core-storage is called character, the 1410 stores alphameric characters internally in binary-coded decimal form, spanning 6 bits called BA8421. When the character is a code or is the first character in a field, another bit. An odd parity bit, called C, is also included, arithmetic is 10-based with the ones position at the high- and the most significant decimal digit at the low-address end of a multi-digit field, thus of ″big-endian″ style. This pertains for both, the calculation for the access of operands and for the various operands of the arithmetic instructions
7.
Unit record equipment
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Unit record machines came to be as ubiquitous in industry and government in the first two-thirds of the twentieth century as computers became in the last third. They allowed large volume, sophisticated data-processing tasks to be accomplished before electronic computers were invented and this data processing was accomplished by processing punched cards through various unit record machines in a carefully choreographed progression. This progression, or flow, from machine to machine was often planned and documented with detailed flowcharts that used standardized symbols for documents, the operation of many machines was directed by the use of a removable plugboard or control panel. Initially all machines were manual or electromechanical, the first use of an electronic component was in 1940 when a gas triode vacuum tube replaced a relay in an IBM card sorter. Electronic components were used on other machines beginning in the late 1940s, IBM was the largest supplier of unit record equipment and this article largely reflects IBM practice and terminology. In the 1880s Herman Hollerith invented the recording of data on a medium that could then be read by a machine, prior uses of machine readable media had been for lists of instructions to drive programmed machines such as Jacquard looms and mechanized musical instruments. After some initial trials with paper tape, he settled on punched cards, to process these punched cards, sometimes referred to as Hollerith cards, he invented the keypunch, sorter, and tabulator unit record machines. These inventions were the foundation of the processing industry. The tabulator used electromechanical relays to increment mechanical counters, Holleriths method was used in the 1890 census. The bureaus contract disputes with Hollerith led to the formation of the Census Machine Shop where James Powers and others developed new machines for part of the 1910 census processing. Powers left the Census Bureau in 1911, with rights to patents for the machines he developed, in 1927 Powers company was acquired by Remington Rand. In 1919 Fredrik Rosing Bull, after examining Holleriths machines, began developing unit record machines for his employer, bulls patents were sold in 1931, constituting the basis for Groupe Bull. Punched card technology had developed into a powerful tool for business data-processing. 1884, Herman Hollerith files a patent application titled Art of Compiling Statistics, patent 395,782 on January 8,1889. 1909, The Tabulator Limited renamed as British Tabulating Machine Company,1910, Tabulators built by the Census Machine Shop print results. 1910, Willy Heidinger, an acquaintance of Hollerith, licenses Hollerith’s The Tabulating Machine Company patents,1911, Computing-Tabulating-Recording Company, a holding company, formed by the amalgamation of The Tabulating Machine Company and three other companies. 1911, James Powers forms Powers Tabulating Machine Company, later renamed Powers Accounting Machine Company, Powers had been employed by the Census Bureau to work on tabulating machine development and was given the right to patent his inventions there. The machines he developed sensed card punches mechanically, as opposed to Holleriths electric sensing,1912, The first Powers horizontal sorting machine
8.
Punched card
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A punched card or punch card is a piece of stiff paper that can be used to contain digital information represented by the presence or absence of holes in predefined positions. The information might be data for data processing applications or, in earlier examples, the terms IBM card, or Hollerith card specifically refer to punched cards used in semiautomatic data processing. Many early digital computers used punched cards, often prepared using keypunch machines, while punched cards are now obsolete as a recording medium, as of 2012, some voting machines still use punched cards to record votes. Basile Bouchon developed the control of a loom by punched holes in paper tape in 1725, in 1801 Joseph Marie Jacquard demonstrated a mechanism to automate loom operation. A number of punched cards were linked into a chain of any length, each card held the instructions for shedding and selecting the shuttle for a single pass. It is considered an important step in the history of computing hardware, semen Korsakov was reputedly the first to use the punched cards in informatics for information store and search. Korsakov announced his new method and machines in September 1832, rather than seeking patents, charles Babbage proposed the use of Number Cards, pierced with certain holes and stand opposite levers connected with a set of figure wheels. Advanced they push in those levers opposite to which there are no holes on the card, Herman Hollerith invented the recording of data on a medium that could then be read by a machine. Prior uses of machine readable media, such as those above, had been for control, after some initial trials with paper tape, he settled on punched cards. Developing punched card data processing technology for the 1890 US census, other companies entering the punched card business included the Powers Accounting Machine Company, Remington Rand, and Groupe Bull. Both IBM and Remington Rand tied punched card purchases to machine leases, in 1932, the US government took both to court on this issue. IBM viewed its business as providing a service and that the cards were part of the machine, IBM fought all the way to the Supreme Court and lost in 1936, the court ruling that IBM could only set card specifications. According to the IBM Archives, By 1937, IBM had 32 presses at work in Endicott, N. Y. printing, cutting and stacking five to 10 million punched cards every day. Punched cards were used as legal documents, such as U. S. Government checks. Punched card technology developed into a tool for business data-processing. By 1950 punched cards had become ubiquitous in industry and government, do not fold, spindle or mutilate, a generalized version of the warning that appeared on some punched cards, became a motto for the post-World War II era. In 1955 IBM signed a consent decree requiring, amongst other things, tom Watson Jr. s decision to sign this decree, where IBM saw the punched card provisions as the most significant point, completed the transfer of power to him from Thomas Watson, Sr. The UNITYPER introduced magnetic tape for data entry in the 1950s, during the 1960s, the punched card was gradually replaced as the primary means for data storage by magnetic tape, as better, more capable computers became available
9.
Ford Model T
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The Ford Model T is an automobile that was produced by Ford Motor Company from October 1,1908, to May 26,1927. The Ford Model T was named the most influential car of the 20th century in the 1999 Car of the Century competition, ahead of the BMC Mini, Citroën DS, and Volkswagen Type 1. With 16.5 million sold it stands eighth on the top ten list of most sold cars of all time as of 2012, although automobiles had already existed for decades, they were still mostly scarce and expensive at the Model Ts introduction in 1908. Positioned as reliable, easily maintained mass market transportation, it was a runaway success, in a matter of days after the release,15,000 orders were placed. The first production Model T was produced on August 12,1908 and left the factory on September 27,1908, at the Ford Piquette Avenue Plant in Detroit, Michigan. On May 26,1927, Henry Ford watched the 15 millionth Model T Ford roll off the line at his factory in Highland Park. There were several cars produced or prototyped by Henry Ford from the founding of the company in 1903 until the Model T was introduced, although he started with the Model A, there were not 19 production models, some were only prototypes. The production model immediately before the Model T was the Model S, a version of the companys largest success to that point. The follow-up was the Ford Model A, the company publicity said this was because the new car was such a departure from the old that Henry wanted to start all over again with the letter A. The Model T was Fords first automobile mass-produced on moving assembly lines with completely interchangeable parts, Henry Ford said of the vehicle, I will build a car for the great multitude. It will be enough for the family, but small enough for the individual to run. It will be constructed of the best materials, by the best men to be hired, after the simplest designs that modern engineering can devise. But it will be so low in price that no man making a good salary will be unable to own one –, although credit for the development of the assembly line belongs to Ransom E. The Model T was designed by Childe Harold Wills, and Hungarian immigrants Joseph A. Galamb, Henry Love, C. J. Smith, Gus Degner and Peter E. Martin were also part of the team. Production of the Model T began in the quarter of 1908. Collectors today sometimes classify Model Ts by build years and refer to these as model years and this is a retroactive classification scheme, the concept of model years as we conceive it today did not exist at the time. The nominal model designation was Model T, although design revisions did occur during the two decades of production. The Model T had a front-mounted 177-cubic-inch inline four-cylinder engine, producing 20 hp, according to Ford Motor Company, the Model T had fuel economy on the order of 13–21 mpg‑US
10.
IBM 1402
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The IBM1402 was a high speed card reader/punch introduced on October 5,1959 as a peripheral input/output device for the IBM1401 computer. It was later used with other computers of the IBM1400 series and it was adapted as the IBM1622 Card Read-Punch for the IBM1620 and provided the basic design for the models 2501,2520 and 2540 equipment used with the IBM System/360 product line. Card read speed up to 800 punched cards per minute or 450 cards per minute, Card input file for 3000 cards or feed hopper for 1200 cards. Three stackers with approximately 1000-card capacity hold cards after they are read, Card punch speed up to 250 cards per minute. Three stackers of approximately 1000-card after cards are punched, the 2/8 stacker is shared by the card reader and punch, but timing considerations make it difficult to use for merging operations. Option to read from the punch feed, the 1402 uses IBM 80-column punched card format, although an option was available to process 51-column cards. A column Binary option allowed cards with any combination of holes to be read, both the reader and punch mechanisms count the number of holes in each column at a separate station. An error is indicated and the mechanism stops if the number of holes counted at the read station differs from the number of holes counted at the first, check station or punched at the first station. In addition, when not operating in column-binary mode, the reader indicates an error and stops if the punch combination in any column does not indicate a valid character
11.
IBM 1403
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The IBM1403 line printer was introduced as part of the IBM1401 computer in 1959 and had an especially long life in the IBM product line. The original model could print 600 lines of text per minute and could skip blank lines at up to 75 inches per second, the standard model had 120 print positions. An additional 12 positions were available as an option, a print chain with up to 15 copies of the character set spun horizontally in front of the ribbon and paper. Hammers struck the paper from behind at exactly the moment to print a character as it went by. In later models, the print chain was replaced by a print train, the 1403 chain or train contained 240 characters, however numerous duplications allowed a line to be printed in less than the 0.4 s required for one full rotation. The original standard A chain contained 48 different characters, repeated five times each, - * % $ / & # @ ⌑ ⧧ appeared eight, four or two times each. Special chains or trains could be ordered for other character sets, scientific users, for example, would use a chain that had the left parenthesis, the right parenthesis, and the plus sign in place of the per cent sign, the lozenge, and the ampersand. The numerics chain had 15 copies each of only 16 characters, the T chain for general text had two copies of 120 characters, including upper-and lower-case letters and numerous special symbols. The ink ribbon was a roll the width of the print area that was positioned between the print chain and the paper. The roll came in two parts, the roll and take-up roll. The roll was wound and rewound during printing. Like most IBM printers of the era, the 1403 used fan-folded paper with perforated edges for tractor feeding. A carriage control tape or, later, a buffer, under control, specified form length. An IBM1403 printer played a role in Stanley Kubricks 1964 movie Dr. Strangelove. The overstrike capability of the printer was used to generate a range of grey-scale equivalents. Many images were scanned, pixelated and could be reproduced on the 1403 and these were noisy machines, especially when the cover was raised. Some people were able to text that used the timing of the print hammers to generate desired frequencies. Prior to the introduction of the model 1403, IBM printers utilized technology originally developed for their line of accounting machines, models 402 and 405 used type bars
12.
Groupe Bull
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Bull SAS is a French-owned computer company headquartered in Les Clayes-sous-Bois, in the western suburbs of Paris. The company has also known at various times as Bull General Electric, Honeywell Bull, CII Honeywell Bull. Bull was founded in 1931, as H. W. Egli - Bull, after a reorganization in 1933, with new owners coming in, the name was changed to Compagnie des Machines Bull. The company has undergone many takeovers and mergers since its formation, in particular, it has had various ownership relations with General Electric, Honeywell, and NEC from the 1960s to the 1980s, and with Motorola, Debeka, and France Télécom more recently. It acquired Honeywell Information Systems in the late 1980s, and later also had a share of Zenith Data Systems, Bull was nationalised in 1982 and was merged with most of the rest of the French computer industry. In 1994, the company was re-privatised, Bull has a worldwide presence in more than 100 countries, and is particularly active in the defense, finance, health care, manufacturing, public and telecommunication sectors. In August,2014 the French IT company Atos announced that it had acquired a stake in Bull SA through a tender offer launched in May. Atos announced plans in October,2014 to buy out or squeeze out the remaining share, the Hoox range of secure mobiles and smartphones ensures confidentiality of voice, SMS, e-mail and data communication. Storebrand integrated his device into its operations in 1921, the following year Bull sold his second machine to the Danish insurer Hafnia who had learned of the technology through an article in an insurance trade magazine. At the time of Bulls death of cancer in 1925 at the age of 43, the commercial and technical development of the machines continued under the direction of Bulls childhood friend and long-time collaborator Reidar Knutsen along with his brother Kurt Andréas Knutsen. As the business grew several outside investors were brought in, leading to the incorporation of the company H. W. Egli Bull in 1931, in 1933 more investors joined and the company changed its name to Compagnie des Machines Bull, a name it would keep until 1964. The Eagle System was used by the Gaddafi regime to spy on citizens, a judicial inquiry was opened by the French government in May 2012 following allegations of complicity in torture by the International Federation for Human Rights. In March 2012 Groupe Bull divested itself of the Eagle System, selling it for the sum of 4 million euros to Nexa Technologies, Bull, A World-Wide Company Born in Europe. IEEE Annals of the History of Computing, History of Bull Extracted and translated from Science et Vie Micro magazine, No. 74, July–August,1990, The very international history of a French giant Official website
13.
Peripheral
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A peripheral is an ancillary device used to put information into and get information out of the computer. Touchscreens are an example that combines different devices into a hardware component that can be used both as an input and output device. A peripheral device is defined as any auxiliary device such as a computer mouse or keyboard that connects to. Other examples of peripherals are image scanners, tape drives, microphones, loudspeakers, webcams, common input peripherals include keyboards, computer mice, graphic tablets, touchscreens, barcode readers, image scanners, microphones, webcams, game controllers, light pens, and digital cameras. Common output peripherals include computer displays, printers, projectors, computer hardware Controller Display device Expansion card Punched card input/output Punched tape Video game accessory
14.
Mainframe computer
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The term originally referred to the large cabinets called main frames that housed the central processing unit and main memory of early computers. Later, the term was used to distinguish high-end commercial machines from less powerful units, most large-scale computer system architectures were established in the 1960s, but continue to evolve. Their high stability and reliability enable these machines to run uninterrupted for decades, Mainframes are defined by high availability, one of the main reasons for their longevity, since they are typically used in applications where downtime would be costly or catastrophic. The term reliability, availability and serviceability is a characteristic of mainframe computers. Proper planning and implementation is required to exploit these features, and if improperly implemented, in the late 1950s, most mainframes had no explicitly interactive interface, but only accepted sets of punched cards, paper tape, or magnetic tape to transfer data and programs. In cases where interactive terminals were supported, these were used almost exclusively for applications rather than program development, typewriter and Teletype devices were also common control consoles for system operators through the 1970s, although ultimately supplanted by keyboard/display devices. By the early 1970s, many mainframes acquired interactive user interfaces and operated as timesharing computers, users gained access through specialized terminals or, later, from personal computers equipped with terminal emulation software. By the 1980s, many mainframes supported graphical terminals, and terminal emulation and this format of end-user computing reached mainstream obsolescence in the 1990s due to the advent of personal computers provided with GUIs. After 2000, most modern mainframes have partially or entirely phased out classic green screen terminal access for end-users in favour of Web-style user interfaces, the infrastructure requirements were drastically reduced during the mid-1990s, when CMOS mainframe designs replaced the older bipolar technology. IBM claimed that its newer mainframes could reduce data center energy costs for power and cooling, modern mainframes can run multiple different instances of operating systems at the same time. This technique of virtual machines allows applications to run as if they were on physically distinct computers, in this role, a single mainframe can replace higher-functioning hardware services available to conventional servers. While mainframes pioneered this capability, virtualization is now available on most families of computer systems, Mainframes can add or hot swap system capacity without disrupting system function, with specificity and granularity to a level of sophistication not usually available with most server solutions. Modern mainframes, notably the IBM zSeries, System z9 and System z10 servers, such a two-mainframe installation can support continuous business service, avoiding both planned and unplanned outages. In practice many customers use multiple mainframes linked either by Parallel Sysplex and shared DASD, or with shared, Mainframes are designed to handle very high volume input and output and emphasize throughput computing. Since the late-1950s, mainframe designs have included subsidiary hardware which manage the I/O devices and it is common in mainframe shops to deal with massive databases and files. Gigabyte to terabyte-size record files are not unusual, compared to a typical PC, mainframes commonly have hundreds to thousands of times as much data storage online, and can access it reasonably quickly. Other server families also offload I/O processing and emphasize throughput computing, Mainframes also have execution integrity characteristics for fault tolerant computing. This hardware-level feature, also found in HPs NonStop systems, is known as lock-stepping, not all applications absolutely need the assured integrity that these systems provide, but many do, such as financial transaction processing
15.
IBM 7090
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The IBM7090 was a second-generation transistorized version of the earlier IBM709 vacuum tube mainframe computers and was designed for large-scale scientific and technological applications. The 7090 was the member of the IBM 700/7000 series scientific computers. The first 7090 installation was in November 1959, in 1960, a typical system sold for $2.9 million or could be rented for $63,500 a month. The 7090 used a 36-bit word length, with a space of 32,768 words. It operated with a memory cycle of 2.18 μs. With a processing speed of around 100 Kflop/s, the 7090 was six times faster than the 709, although the 709 was a superior machine to its predecessor, the 704, it was being built and sold at the time that transistor circuitry was supplanting vacuum tube circuits. Hence, IBM redeployed its 709 engineering group to the design of a transistorized successor and that project became called the 709-T, which because of the sound when spoken, quickly shifted to the nomenclature 7090. Similarly, the related machines such as the 7070 and other 7000 series equipment were called by names of digit - digit - decade, an upgraded version, the IBM7094, was first installed in September 1962. It had seven index registers, instead of three on the earlier machines, the 7094 console had a distinctive box on top that displayed lights for the four new index registers. Photos The 7094 introduced double-precision floating point and additional instructions, but was backward compatible with the 7090. Minor changes in instruction formats, particularly the way the additional index registers were addressed, sometimes caused problems. On the earlier models, when more than one bit was set in the tag field, on the 7094, if the three-bit tag field was not zero, it selected just one of seven index registers, however the or behavior remained available in a multiple tag compatibility mode. In 1963, IBM introduced two new, lower cost machines called the IBM7040 and 7044, a 7094/7044 Direct Coupled System was introduced later, with the 7094 performing computation while the 7044 handled Input/Output. The 7090 used germanium transistors and germanium diffused junction drift transistors. The 7090 used the Standard Modular System cards using current-mode logic some using diffused junction drift transistors, the basic instruction format was the same as the IBM709, a three-bit prefix, 15-bit decrement, three-bit tag, and 15-bit address. The prefix field specified the class of instruction, the decrement field often contained an immediate operand to modify the results of the operation, or was used to further define the instruction type. The three bits of the tag specified three index registers, the contents of which were subtracted from the address to produce an effective address, the address field contained either an address or an immediate operand. Fixed-point numbers were stored in binary sign/magnitude format, the double-precision number was stored in memory in an even-odd pair of consecutive words, the sign and exponent in the second word were ignored when the number was used as an operand
16.
Magnetic tape
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Magnetic tape is a medium for magnetic recording, made of a thin, magnetizable coating on a long, narrow strip of plastic film. It was developed in Germany, based on magnetic wire recording, devices that record and play back audio and video using magnetic tape are tape recorders and video tape recorders. A device that stores data on magnetic tape is a tape drive. Magnetic tape revolutionized broadcast and recording, when all radio was live, it allowed programming to be recorded. At a time when gramophone records were recorded in one take, it allowed recordings to be made in multiple parts, which were then mixed and edited with tolerable loss in quality. It was a key technology in computer development, allowing unparalleled amounts of data to be mechanically created, stored for long periods. Nowadays, other technologies can perform the functions of magnetic tape, in many cases, these technologies are replacing tape. Despite this, innovation in the technology continues, and Sony, over years, magnetic tape made in the 1970s and 1980s can suffer from a type of deterioration called sticky-shed syndrome. Caused by hydrolysis of the binder of the tape, it can render the tape unusable, the oxide side of a tape is the surface that can be magnetically manipulated by a tape head. This is the side that stores the information, the side is simply a substrate to hold the tape together. The name originates from the fact that the side of most tapes is made of an oxide of iron. Magnetic tape was invented for recording sound by Fritz Pfleumer in 1928 in Germany, based on the invention of magnetic wire recording by Oberlin Smith in 1888, pfleumers invention used a ferric oxide powder coating on a long strip of paper. This invention was developed by the German electronics company AEG, which manufactured the recording machines and BASF. In 1933, working for AEG, Eduard Schuller developed the ring-shaped tape head, previous head designs were needle-shaped and tended to shred the tape. An important discovery made in this period was the technique of AC biasing, due to the escalating political tensions, and the outbreak of World War II, these developments were largely kept secret. A wide variety of recorders and formats have developed since, most significantly reel-to-reel, the practice of recording and editing audio using magnetic tape rapidly established itself as an obvious improvement over previous methods. Many saw the potential of making the same improvements in recording television, television signals are similar to audio signals. A major difference is that video signals use more bandwidth than audio signals, existing audio tape recorders could not practically capture a video signal
17.
Spooling
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In computing, spooling is a specialized form of multi-programming for the purpose of copying data between different devices. In contemporary systems it is used for mediating between a computer application and a slow peripheral, such as a printer. Spooling allows programs to hand off work to be done by the peripheral and then proceed to other tasks, a dedicated program, the spooler, maintains an orderly sequence of jobs for the peripheral and feeds it data at its own rate. The spool itself refers to the sequence of jobs, or the area where they are held. In many cases the spooler is able to drive devices at their full rated speed with minimal impact on other processing, spooling is a combination of buffering and queueing. Nowadays, the most common use of spooling is printing, documents formatted for printing are stored in a queue at the speed of the computer, then retrieved and printed at the speed of the printer. Multiple processes can write documents to the spool without waiting, and can perform other tasks. For example, when a large organization prepares payroll checks, the computation takes only a few minutes or even seconds, if the payroll program printed checks directly, it would be unable to proceed to other computations until all the checks were printed. Similarly, before spooling was added to PC operating systems, word processors were unable to do anything else, including interact with the user, a print server applies spooling techniques to allow many computers to share the same printer or group of printers. Print spoolers can often be configured to add a banner page to the front of each document and these separate documents from each other, identify each document and often also state who printed it. Banner pages are valuable in office environments where people share a small number of printers. Depending on the configuration, banner pages might be generated on each client computer, or on a print server. On printers using fanfold continuous forms a leading banner page would often be printed twice, the page might include lines printed over the fold, which would be visible along the edge of a stack of printed output, allowing the operator to easily separate the jobs. Some systems would also print a page at the end of each job. Spooling is also used to access to punched card readers and punches, magnetic tape drives. A batch processing system uses spooling to maintain a queue of ready-to-run tasks, peripherals device have always been much slower than core processing units. This was a severe problem for early mainframes. For example, a job which read punched cards or generated printed output directly was forced to run at the speed of the mechanical devices
18.
IBM System/360
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The IBM System/360 is a mainframe computer system family that was announced by IBM on April 7,1964, and delivered between 1965 and 1978. It was the first family of computers designed to cover the range of applications, from small to large. The design made a distinction between architecture and implementation, allowing IBM to release a suite of compatible designs at different prices. The launch of the System/360 family introduced IBMs Solid Logic Technology, the slowest System/360 model announced in 1964, the Model 30, could perform up to 34,500 instructions per second, with memory from 8 to 64 KB. The 1967 IBM System/360 Model 91 could do up to 16.6 million instructions per second, up to 8 megabytes of slower Large Capacity Storage was also available. Many consider the one of the most successful computers in history. The chief architect of System/360 was Gene Amdahl, and the project was managed by Fred Brooks, the commercial release was piloted by another of Watsons lieutenants, John R. Opel, who managed the launch of IBM’s System 360 mainframe family in 1964. Application level compatibility for System/360 software is maintained to present day with the System z servers, contrasting with at-the-time normal industry practice, IBM created an entire series of computers, from small to large, low to high performance, all using the same instruction set. This feat allowed customers to use a model and then upgrade to larger systems as their needs increased without the time. This flexibility greatly lowered barriers to entry, with other vendors, customers had to choose between machines they could outgrow and machines that were potentially overpowered. This meant that many simply did not buy computers. IBM initially announced a series of six computers and forty common peripherals, IBM eventually delivered fourteen models, including rare one-off models for NASA. The initial announcement in 1964 included Models 30,40,50,60,62, the first three were low- to middle-range systems aimed at the IBM1400 series market. All three first shipped in mid-1965, the last three, intended to replace the 7000 series machines, never shipped and were replaced by the 65 and 75, which were first delivered in November 1965, and January 1966, respectively. Later additions to the low-end included models 20,22, and 25, the Model 20 had several sub-models, sub-model 5 was at the higher end of the model. A succession of high-end machines included the Model 67,85,91,95, the 85 design was intermediate between the System/360 line and the follow-on System/370 and was the basis for the 370/165. There was a System/370 version of the 195, but it did not include Dynamic Address Translation, the implementations differed substantially, using different native data path widths, presence or absence of microcode, yet were extremely compatible. Except where specifically documented, the models were architecturally compatible, the 91, for example, was designed for scientific computing and provided out-of-order instruction execution, but lacked the decimal instruction set used in commercial applications
19.
Honeywell 200
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Introduced to compete with IBMs 1401, the H200 was two or three times faster and, with software support, could execute IBM1401 programs without need for their recompilation or reassembly. The Liberator marketing campaign exploited this compatibility, and was credited in later Honeywell publicity statements with stalling the sales of IBM1401 machines. As designed by Director of Engineering William L. Gordon, the H200 memory consisted of individually addressed characters, each composed of six data bits, the two punctuation bits recorded a word mark and an item mark, while both being set constituted a record mark. The item bit permitted item moves and record moves in addition to word moves, an instruction consisted of a one-character op-code, up to two operand addresses and an optional single character variant. Usually the op-code character would be word-marked, confirming the end of the previous instruction, an item-marked op-code would be handled differently from normal, and this was used in the emulation of IBM1401 instructions that were not directly compatible. The first three bits of an operand address could designate one of six index registers that occupied the first 32 addressable memory locations, the other two possible bit patterns indicated no indexing, or indirect addressing. A Change Address Mode instruction switched between 2-, 3- and 4-character address modes, the address mode specified the number of characters needed for each operand address in instructions. A Change Sequence Mode instruction stored the next instruction address in a memory location and this provided a simple switch between threads within a program, similar to the sequence/cosequence behaviour of the Honeywell 800 series. While the H200 supported operation with just a console, card reader and punch like the IBM1401, IO instructions left punctuation bits unchanged, reading or writing only data bits into memory, and terminating on any record mark encountered. A record mark could be placed at the end of a buffer to prevent any buffer overflow. The 200-series IO instructions were a Peripheral Data Transfer and a Peripheral Control and Branch that explicitly implemented asynchronous IO. The PDT specified a device address, an address and the transfer operation to be started, while the PCB specified a device address. Both used the format Op-code Address I/O unit address Variant, the native assembly language was named Easycoder. The Easycoder assembler generated an object file as a card deck that could be punched to cards or written to magnetic tape instead. The object file began with a bootstrapping routine so that each program could be loaded into memory, from card reader or magnetic tape, the H200 was commonly used as a spooling computer associated with a larger Honeywell 800 series machine. The LINK program running on the H200 handled the OLA, copied punched cards or punched tape to magnetic tape. These promotions, plus an Emett calendar, originated in the UK and were the inspiration of Don Hatton, archived from the original on May 25,2006
20.
Microcode
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Microcode is a technique that imposes an interpreter between the hardware and the architectural level of a computer. As such, the microcode is a layer of hardware-level instructions that implement higher-level machine code instructions or internal state machine sequencing in many digital processing elements. Microcode typically resides in special high-speed memory and translates machine instructions and it separates the machine instructions from the underlying electronics so that instructions can be designed and altered more freely. It also facilitates the building of complex multi-step instructions, while reducing the complexity of computer circuits, writing microcode is often called microprogramming and the microcode in a particular processor implementation is sometimes called a microprogram. Some hardware vendors, especially IBM, use the term microcode as a synonym for firmware, when compared to normal application programs, the elements composing a microprogram exist on a lower conceptual level. To avoid confusion, each microprogram-related element is differentiated by the prefix, microinstruction, microassembler, microprogrammer, microarchitecture. Engineers normally write the microcode during the phase of a processor, storing it in a read-only memory or programmable logic array structure. However, machines also exist that have some or all microcode stored in SRAM or flash memory and this is traditionally denoted as writeable control store in the context of computers, which can be either read-only or read-write memory. Complex digital processors may also more than one control unit in order to delegate sub-tasks that must be performed essentially asynchronously in parallel. A high-level programmer, or even an assembly programmer, does not normally see or change microcode, microprograms consist of series of microinstructions, which control the CPU at a very fundamental level of hardware circuitry. g. 128 bits on a 360/85 with an emulator feature, microcode was originally developed as a simpler method of developing the control logic for a computer. Initially, CPU instruction sets were hardwired, each step needed to fetch, decode, and execute the machine instructions was controlled directly by combinational logic and rather minimal sequential state machine circuitry. Microcode simplified the job by allowing much of the processors behaviour, even late in the design process, microcode could easily be changed, whereas hard-wired CPU designs were very cumbersome to change. Thus, this greatly facilitated CPU design, the IBM Future Systems project and Data General Fountainhead Processor are examples of this. During the 1970s, CPU speeds grew more quickly than memory speeds and numerous techniques such as memory block transfer, memory pre-fetch, high-level machine instructions, made possible by microcode, helped further, as fewer more complex machine instructions require less memory bandwidth. For example, an operation on a string can be done as a single machine instruction. Architectures with instruction sets implemented by complex microprograms included the IBM System/360, the approach of increasingly complex microcode-implemented instruction sets was later called CISC. An alternate approach, used in microprocessors, is to use PLAs or ROMs mainly for instruction decoding
21.
Emulator
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In computing, an emulator is hardware or software that enables one computer system to behave like another computer system. An emulator typically enables the host system to run software or use peripheral devices designed for the guest system, emulation refers to the ability of a computer program in an electronic device to emulate another program or device. Many printers, for example, are designed to emulate Hewlett-Packard LaserJet printers because so much software is written for HP printers. If a non-HP printer emulates an HP printer, any software written for a real HP printer will also run in the non-HP printer emulation and produce equivalent printing. Since at least the 1990s until today, some video game enthusiasts use emulators to play 1980s arcade games using the original 1980s programming code, a hardware emulator is an emulator which takes the form of a hardware device. In a theoretical sense, the Church-Turing thesis implies that any operating environment can be emulated within any other environment. However, in practice, it can be difficult, particularly when the exact behavior of the system to be emulated is not documented and has to be deduced through reverse engineering. Emulation is a strategy in digital preservation to combat obsolescence, emulation addresses the original hardware and software environment of the digital object, and recreates it on a current machine. The emulator allows the user to have access to any kind of application or operating system on a current platform and he further states that this should not only apply to out of date systems, but also be upwardly mobile to future unknown systems. Potentially better graphics quality than original hardware, potentially additional features original hardware didnt have. Emulators maintain the look, feel, and behavior of the digital object. Despite the original cost of developing an emulator, it may prove to be the more cost efficient solution over time, many emulators have already been developed and released under GNU General Public License through the open source environment, allowing for wide scale collaboration. Emulators allow software exclusive to one system to be used on another, for example, a PlayStation 2 exclusive video game could be played on a PC using an emulator. This is especially useful when the system is difficult to obtain. Copyright laws are not yet in effect to address saving the documentation and these protections make it more difficult to design emulators, since they must be accurate enough to avoid triggering the protections, whose effects may not be obvious. Emulators require better hardware than the system has. Because of its use of digital formats, new media art relies heavily on emulation as a preservation strategy. The paradox is that the emulation and the emulator have to be made to work on future computers, emulation techniques are commonly used during the design and development of new systems
22.
Read-only memory
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Read-only memory is a type of non-volatile memory used in computers and other electronic devices. Data stored in ROM can only be modified slowly, with difficulty, or not at all, strictly, read-only memory refers to memory that is hard-wired, such as diode matrix and the later mask ROM, which cannot be changed after manufacture. Although discrete circuits can be altered in principle, integrated circuits cannot and that such memory can never be changed is a disadvantage in many applications, as bugs and security issues cannot be fixed, and new features cannot be added. More recently, ROM has come to include memory that is read-only in normal operation, the simplest type of solid-state ROM is as old as the semiconductor technology itself. Combinational logic gates can be joined manually to map n-bit address input onto arbitrary values of m-bit data output, with the invention of the integrated circuit came mask ROM. In mask ROM, the data is encoded in the circuit. This leads to a number of disadvantages, It is only economical to buy mask ROM in large quantities. The turnaround time between completing the design for a mask ROM and receiving the finished product is long, for the same reason, mask ROM is impractical for R&D work since designers frequently need to modify the contents of memory as they refine a design. If a product is shipped with faulty mask ROM, the way to fix it is to recall the product. Subsequent developments have addressed these shortcomings, PROM, invented in 1956, allowed users to program its contents exactly once by physically altering its structure with the application of high-voltage pulses. This addressed problems 1 and 2 above, since a company can order a large batch of fresh PROM chips. The 1971 invention of EPROM essentially solved problem 3, since EPROM can be reset to its unprogrammed state by exposure to strong ultraviolet light. All of these technologies improved the flexibility of ROM, but at a significant cost-per-chip, rewriteable technologies were envisioned as replacements for mask ROM. The most recent development is NAND flash, also invented at Toshiba, as of 2007, NAND has partially achieved this goal by offering throughput comparable to hard disks, higher tolerance of physical shock, extreme miniaturization, and much lower power consumption. Every stored-program computer may use a form of storage to store the initial program that runs when the computer is powered on or otherwise begins execution. Likewise, every non-trivial computer needs some form of memory to record changes in its state as it executes. Forms of read-only memory were employed as non-volatile storage for programs in most early stored-program computers, consequently, ROM could be implemented at a lower cost-per-bit than RAM for many years. Most home computers of the 1980s stored a BASIC interpreter or operating system in ROM as other forms of storage such as magnetic disk drives were too costly
23.
Computer History Museum
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The Computer History Museum is a museum established in 1996 in Mountain View, California, US. The Museum is dedicated to preserving and presenting the stories and artifacts of the information age, the museums origins date to 1968 when Gordon Bell began a quest for a historical collection and, at that same time, others were looking to preserve the Whirlwind computer. The resulting Museum Project had its first exhibit in 1975, located in a coat closet in a DEC lobby. In 1978, the museum, now The Digital Computer Museum, moved to a larger DEC lobby in Marlborough, maurice Wilkes presented the first lecture at TDCM in 1979 – the presentation of such lectures has continued to the present time. TDCM incorporated as The Computer Museum in 1982, in 1984, TCM moved to Boston, locating on Museum Wharf. In 1996/1997, The TCM History Center in Silicon Valley was established, a site at Moffett Field was provided by NASA, in 1999, TCMHC incorporated and TCM ceased operation, shipping its remaining artifacts to TCMHC in 2000. The name TCM had been retained by the Boston Museum of Science so, in 2000, in 2003, CHM opened its new building, at 1401 N. Shoreline Blvd in Mountain View, California, to the public. The facility was heavily renovated and underwent a two-year $19 million makeover before reopening on January 2011. The Computer History Museum claims to house the largest and most significant collection of computing artifacts in the world, the collection comprises nearly 90,000 objects, photographs and films, as well as 4,000 feet of cataloged documentation and several hundred gigabytes of software. The CHM oral history program conducts video interviews around the history of computing and networking, the museums 25, 000-square-foot exhibit Revolution, The First 2000 Years of Computing, opened to the public on January 13,2011. It covers the history of computing in 20 galleries, from the abacus to the Internet, the entire exhibition is also available online. The museum features a Liquid Galaxy in the “Going Places, A History of Silicon Valley” exhibit, the exhibit features 20 preselected locations that visitors can fly to on the Liquid Galaxy. An operating Difference Engine designed by Charles Babbage in the 1840s and it had been on loan since 2008 from its owner, Nathan Myhrvold, a former Microsoft executive. Former media executive John Hollar was appointed CEO of The Computer History Museum in July 2008, in 2012 the APL programming language followed. In February 2013 Adobe Systems, Inc. donated the Photoshop 1.0.1 source code to the collection, on October 21,2014, Xerox Altos source code and other resources followed. The CHM Fellows are exceptional men and women whose ideas have changed the world, the first fellow was Rear Admiral Grace Hopper in 1987. The fellows program has grown to 70 members as of 2015, vintage Computer Festival held annually at The Computer History Museum Computer museums History of computing History of computer science Bell, Gordon. Out of a Closet, The Early Years of the Computer * Museum, official website Computer History Museums channel on YouTube The Computer Museum Archive
24.
India
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India, officially the Republic of India, is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and it is bounded by the Indian Ocean on the south, the Arabian Sea on the southwest, and the Bay of Bengal on the southeast. It shares land borders with Pakistan to the west, China, Nepal, and Bhutan to the northeast, in the Indian Ocean, India is in the vicinity of Sri Lanka and the Maldives. Indias Andaman and Nicobar Islands share a border with Thailand. The Indian subcontinent was home to the urban Indus Valley Civilisation of the 3rd millennium BCE, in the following millennium, the oldest scriptures associated with Hinduism began to be composed. Social stratification, based on caste, emerged in the first millennium BCE, early political consolidations took place under the Maurya and Gupta empires, the later peninsular Middle Kingdoms influenced cultures as far as southeast Asia. In the medieval era, Judaism, Zoroastrianism, Christianity, and Islam arrived, much of the north fell to the Delhi sultanate, the south was united under the Vijayanagara Empire. The economy expanded in the 17th century in the Mughal empire, in the mid-18th century, the subcontinent came under British East India Company rule, and in the mid-19th under British crown rule. A nationalist movement emerged in the late 19th century, which later, under Mahatma Gandhi, was noted for nonviolent resistance, in 2015, the Indian economy was the worlds seventh largest by nominal GDP and third largest by purchasing power parity. Following market-based economic reforms in 1991, India became one of the major economies and is considered a newly industrialised country. However, it continues to face the challenges of poverty, corruption, malnutrition, a nuclear weapons state and regional power, it has the third largest standing army in the world and ranks sixth in military expenditure among nations. India is a constitutional republic governed under a parliamentary system. It is a pluralistic, multilingual and multi-ethnic society and is home to a diversity of wildlife in a variety of protected habitats. The name India is derived from Indus, which originates from the Old Persian word Hindu, the latter term stems from the Sanskrit word Sindhu, which was the historical local appellation for the Indus River. The ancient Greeks referred to the Indians as Indoi, which translates as The people of the Indus, the geographical term Bharat, which is recognised by the Constitution of India as an official name for the country, is used by many Indian languages in its variations. Scholars believe it to be named after the Vedic tribe of Bharatas in the second millennium B. C. E and it is also traditionally associated with the rule of the legendary emperor Bharata. Gaṇarājya is the Sanskrit/Hindi term for republic dating back to the ancient times, hindustan is a Persian name for India dating back to the 3rd century B. C. E. It was introduced into India by the Mughals and widely used since then and its meaning varied, referring to a region that encompassed northern India and Pakistan or India in its entirety
25.
Pakistan
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Pakistan, officially the Islamic Republic of Pakistan, is a federal parliamentary republic in South Asia on the crossroads of Central Asia and Western Asia. It is the sixth-most populous country with a population exceeding 200 million people, in terms of area, it is the 33rd-largest country in the world with an area covering 881,913 square kilometres. It is separated from Tajikistan by Afghanistans narrow Wakhan Corridor in the north, Pakistan is unique among Muslim countries in that it is the only country to have been created in the name of Islam. As a result of the Pakistan Movement led by Muhammad Ali Jinnah and it is an ethnically and linguistically diverse country, with a similarly diverse geography and wildlife. Initially a dominion, Pakistan adopted a constitution in 1956, becoming an Islamic republic, an ethnic civil war in 1971 resulted in the secession of East Pakistan as the new country of Bangladesh. The new constitution stipulated that all laws were to conform to the injunctions of Islam as laid down in the Quran. Pakistan has an economy with a well-integrated agriculture sector. The Pakistani economy is the 24th-largest in the world in terms of purchasing power and it is ranked among the emerging and growth-leading economies of the world, and is backed by one of the worlds largest and fastest-growing middle classes. The post-independence history of Pakistan has been characterised by periods of military rule, the country continues to face challenging problems such as illiteracy, healthcare, and corruption, but has substantially reduced poverty and terrorism and expanded per capita income. It is also a member of CERN. Pakistan is a signatory to the Kyoto Protocol, the Paris Agreement, the name Pakistan literally means land of the pure in Urdu and Persian. It is a play on the word pāk meaning pure in Persian and Pashto, the letter i was incorporated to ease pronunciation and form the linguistically correct and meaningful name. Some of the earliest ancient human civilisations in South Asia originated from areas encompassing present-day Pakistan, the earliest known inhabitants in the region were Soanian during the Lower Paleolithic, of whom stone tools have been found in the Soan Valley of Punjab. The Vedic Civilization, characterised by Indo-Aryan culture, laid the foundations of Hinduism, Multan was an important Hindu pilgrimage centre. The Vedic civilisation flourished in the ancient Gandhāran city of Takṣaśilā, the Indo-Greek Kingdom founded by Demetrius of Bactria included Gandhara and Punjab and reached its greatest extent under Menander, prospering the Greco-Buddhist culture in the region. Taxila had one of the earliest universities and centres of education in the world. At its zenith, the Rai Dynasty of Sindh ruled this region, the Pala Dynasty was the last Buddhist empire, which, under Dharampala and Devapala, stretched across South Asia from what is now Bangladesh through Northern India to Pakistan. The Arab conqueror Muhammad bin Qasim conquered the Indus valley from Sindh to Multan in southern Punjab in 711 AD, the Pakistan governments official chronology identifies this as the time when the foundation of Pakistan was laid
26.
Pakistan International Airlines
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Pakistan International Airlines commonly known as PIA is the national flag carrier of Pakistan. Its main hub is Karachi while Lahore and Islamabad are its secondary hubs, the airline was founded on 23 October 1946 as Orient Airways, initially based in Calcutta prior to the Partition of British India. It later acquired four Douglas DC-3s, the airline was nationalized on 10 January 1955 and was renamed Pakistan International Airlines. Its first international flight was in 1955, operating to London, via Cairo, PIA has a history of milestones in aviation, it was the first Asian carrier to fly the Lockheed Super Constellation and also was the first non-communist airline to fly to China. It was the second Asian airline to acquire a jet aircraft, more recently, it was the launch customer of the Boeing 777-200LR. The airline also owns The Roosevelt Hotel and Sofitel Paris Scribe Hotel and it is Pakistans largest airline with a fleet of more than 30 aircraft of its own, as well as several aircraft wet-leased from other airlines. As of 2016, PIA is going through a procedure of privatization to shift management from government to the private sector and it employed nearly 14,000 people as of annual report 2015 and the airline has overall punctuality of 88%. PIA operates scheduled services to 22 domestic destinations and 28 international destinations across Asia, Europe, Middle East and it operates nearly 100 flights daily. Pakistan International Airlines can trace its origins to the days when Pakistan had not yet gained independence from the British Raj, around that time, a new airline Orient Airways, was registered in Calcutta on 23 October 1946. In February 1947, the airline bought three Douglas DC-3 aircraft and obtained a license to fly in May of the same year, the airline started its operations in June, offering services from Kolkata to Sittwe and Yangon. On 14 August 1947, Pakistan gained independence and Orient Airways started relief operations for the new country and it was the first and only Muslim owned airline in the British Raj and flew from 1947 to 1955. On 6 June 1954, Orient Airways started its operations by offering services between East- and West Pakistan, with service from Karachi to Dhaka. In addition, the airline introduced two new domestic routes, Karachi–Lahore–Peshawar and Karachi–Quetta–Lahore. However, due to sustained losses being suffered by the airline, on 11 March 1955, Orient Airways merged with the governments proposed airline, becoming Pakistan International Airlines Corporation. The newly formed airline also inaugurated its first international route, Karachi-London Heathrow Airport via Cairo and Rome, the airline continued using DC-3s on domestic routes in Pakistan. In May 1956, PIA ordered five Vickers Viscount 815s, the appointment of Air Marshal Nur Khan as the Managing Director of PIA in 1959 heralded an era of success for PIA. In March 1960, PIA wet-leased a Boeing 707 from Pan American airlines, with the newly acquired aircraft, the airline introduced its first trans-Atlantic route Karachi-New York via London in 1961. In 1962, it expanded its fleet by placing orders for Boeing 720s, Fokker F27 Friendships, from 1962 to 1966, PIA operated its Sikorsky S-61 helicopters for services within East Pakistan
27.
Mountain View, California
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Mountain View is a city located in Santa Clara County, California, United States, named for its views of the Santa Cruz Mountains. From its origins as a stop, it grew to a large suburb with a pedestrian-friendly downtown, free wi-fi. The city borders Palo Alto and the San Francisco Bay to the north, Los Altos to the south, situated in the southern end of the San Francisco Peninsula in the San Francisco Bay Area, Mountain View is home to many high technology companies. In 1956, Shockley Semiconductor Laboratory, the first company to develop silicon semiconductor devices in what came to be known as Silicon Valley, was established in the city by William Shockley. Today, many of the largest technology companies in the world are headquartered in the city, including Google, Mozilla Foundation, Symantec, and Intuit. The original Byte Shop computer store was opened at 1063 El Camino Real, Mountain View by Paul Terrell, the Santa Clara Valley Transportation Authority integrates the city with the neighboring cities of Palo Alto, Los Altos, and Sunnyvale. The Mexican land grant of Rancho Pastoria de las Borregas was given in 1842 by Alta California Governor Juan Alvarado to Francisco Estrada. This grant was passed on to Mariano Castro, who sold half of the land to Martin Murphy, Jr. Eventually. First known as the center of Fremont Twp. before the first California 1852 census. Which meant that it was a predecessor to Mayfield and Palo Alto, Mountain View Station, officially named in 1864, had its beginnings earlier as a stagecoach stop on the route between San Francisco and San Jose, including the Butterfield Overland Mail. & El Camino Real of today, was closer to what was once the town center. The early pioneers were buried at the old cemetery between Mercy & Church, off Castro Street, now the present city Library and park. Reverend Henry Merrill Henderson, born in Maryland, age 35, arrived in Spring of 1852, with his family to meet with relatives Ricketts and he was the first Baptist minister in town and soon was going by horse to Half-Moon Bay, and McCartersville for services. His next-door neighbor arrived later that year, Seligman Weilheimer and brother Samuel from Dossenheim, Baden, Germany, who built at that property, the Fremont twp. population was about 560 by 1860, less Mayfield Post office section, which began north of present San Antonio Road. The towns early growth was due to agriculture, William Bubb later being a figure, buying 80 acres to farm in October 1851. His heirs expanded and intermarried in the area, agriculture remained the primary industry into the middle of the 20th century. The U. S. Navys adjacent 1000 acre Moffet Field Complex began after 1931, after World War II, the population grew significantly with the development of the aerospace and electronics industries. Between 1950 and 1960, the population grew from 6,563 to 30,889, today, high technology is the foundation of the local economy, and there exist few remnants of the citys agricultural past
28.
Raised floor
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A raised floor provides an elevated structural floor above a solid substrate to create a hidden void for the passage of mechanical and electrical services. Such flooring can be installed at varying heights from 2 inches to heights above 4 feet to suit services that may be accommodated beneath, additional structural support and lighting are often provided when a floor is raised enough for a person to crawl or even walk beneath. In data centers, isolated air-conditioning zones are associated with raised floors. Perforated tiles are placed beneath computer systems to direct conditioned air directly to them. In turn, the equipment is often designed to draw cooling air from below. An air conditioning unit then draws air from the room, cools it and this type of floor consists of a gridded metal framework or substructure of adjustable-height supports that provide support for removable floor panels, which are usually 2×2 feet or 60×60 cm. The panels are made of steel-clad particleboard or a steel panel with a cementitious internal core. When using a panel with a cement top surface the panels are left bare and sealed or stained and sealed to create a tile appearance. This bare application is used most often in office area, hallways, lobbies, museums, casinos, many modern computer and equipment rooms employ an underfloor air distribution to ensure even cooling of the room with minimal wasted energy. Conditioned air is provided under the floor and dispersed upward into the room through regularly spaced diffuser tiles, automatic fire protection shutoffs may be required for underfloor ventilation, and additional suppression systems may be installed in case of underfloor fires. Many office buildings now use access flooring to create flexible and sustainable spaces. When underfloor air is designed into a building from the start of the project, Underfloor air requires less space per floor, thereby reducing the overall height of the building, which in turn reduces the cost of the building facade. As more companies construct or renovate buildings to meet LEED underfloor air, the USGBC states that 40-48% of new nonresidential construction is green. Smoke detectors under the floor can be triggered by workers disturbing the dust. To remove panels, a tool with a cup on the end is used. A hook-and-loop lifter may be used on carpeted panels, structural problems, such as rocking panels and gaps between panels, can cause significant damage to equipment and injury to personnel. Regular inspections for the integrity of a raised floor system can help to identify. Equipment and floor damage can happen when using flooring that does not meet load demands, load ratings range from 1,000 pounds to 25,000 pounds
29.
Data center
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A data center is a facility used to house computer systems and associated components, such as telecommunications and storage systems. It generally includes redundant or backup power supplies, redundant data communications connections, environmental controls, large data centers are industrial scale operations using as much electricity as a small town. Data centers have their roots in the computer rooms of the early ages of the computing industry. Early computer systems, complex to operate and maintain, required an environment in which to operate. Many cables were necessary to all the components, and methods to accommodate and organize these were devised such as standard racks to mount equipment, raised floors. A single mainframe required a deal of power, and had to be cooled to avoid overheating. Security became important – computers were expensive, and were used for military purposes. Basic design-guidelines for controlling access to the room were therefore devised. During the boom of the industry, and especially during the 1980s, users started to deploy computers everywhere. However, as information technology operations started to grow in complexity, the advent of Unix from the early 1970s led to the subsequent proliferation of freely available Linux-compatible PC operating-systems during the 1990s. These were called servers, as timesharing operating systems like Unix rely heavily on the model to facilitate sharing unique resources between multiple users. The use of the data center, as applied to specially designed computer rooms. The boom of data centers came during the bubble of 1997–2000. Companies needed fast Internet connectivity and non-stop operation to deploy systems, installing such equipment was not viable for many smaller companies. Many companies started building very large facilities, called Internet data centers, New technologies and practices were designed to handle the scale and the operational requirements of such large-scale operations. These practices eventually migrated toward the data centers, and were adopted largely because of their practical results. Data centers for cloud computing are called cloud data centers, but nowadays, the division of these terms has almost disappeared and they are being integrated into a term data center. Standards documents from accredited professional groups, such as the Telecommunications Industry Association, well-known operational metrics for data-center availability can serve to evaluate the commercial impact of a disruption
30.
Binary-coded decimal
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In computing and electronic systems, binary-coded decimal is a class of binary encodings of decimal numbers where each decimal digit is represented by a fixed number of bits, usually four or eight. Special bit patterns are used for a sign or for other indications. The precise 4-bit encoding may vary however, for technical reasons, the ten states representing a BCD decimal digit are sometimes called tetrades with those dont care-states unused named pseudo-tetrads or pseudo-decimal digit). BCDs principal drawbacks are an increase in the complexity of the circuits needed to implement basic arithmetics. BCD was used in many early computers, and is implemented in the instruction set of machines such as the IBM System/360 series and its descendants. BCD takes advantage of the fact that any one decimal numeral can be represented by a four bit pattern, the most obvious way of encoding digits is natural BCD, where each decimal digit is represented by its corresponding four-bit binary value, as shown in the following table. This is also called 8421 encoding, other encodings are also used, including so-called 4221 and 7421 — named after the weighting used for the bits — and excess-3. For example, the BCD digit 6, 0110b in 8421 notation, is 1100b in 4221, 0110b in 7421, Packed, Two numerals are encoded into a single byte, with one numeral in the least significant nibble and the other numeral in the most significant nibble. To represent numbers larger than the range of a single byte any number of contiguous bytes may be used, also note how packed BCD is more efficient in storage usage as compared to unpacked BCD, encoding the same number in unpacked format would consume twice the storage. Shifting and masking operations are used to pack or unpack a packed BCD digit, other logical operations are used to convert a numeral to its equivalent bit pattern or reverse the process. BCD is very common in systems where a numeric value is to be displayed, especially in systems consisting solely of digital logic. By employing BCD, the manipulation of data for display can be greatly simplified by treating each digit as a separate single sub-circuit. This matches much more closely the reality of display hardware—a designer might choose to use a series of separate identical seven-segment displays to build a metering circuit. If the numeric quantity were stored and manipulated as pure binary, therefore, in cases where the calculations are relatively simple, working throughout with BCD can lead to a simpler overall system than converting to and from binary. Most pocket calculators do all their calculations in BCD, the same argument applies when hardware of this type uses an embedded microcontroller or other small processor. Often, smaller code results when representing numbers internally in BCD format, for these applications, some small processors feature BCD arithmetic modes, which assist when writing routines that manipulate BCD quantities. In Packed BCD, each of the two nibbles of each byte represent a decimal digit, Packed BCD has been in use since at least the 1960s and is implemented in all IBM mainframe hardware since then. Most implementations are big endian, i. e. with the more significant digit in the half of each byte
31.
IBM 1401
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The IBM1401 is a variable wordlength decimal computer that was announced by IBM on October 5,1959. Over 12,000 units were produced and many were leased or resold after they were replaced with newer technology, the 1401 was withdrawn on February 8,1971. These features include, high speed card punching and reading, magnetic tape input and output, high speed printing, stored program, and arithmetic and logical ability. The 1401 may be operated as an independent system, in conjunction with IBM punched card equipment, monthly rental for 1401 configurations started at US$2,500. IBM was pleasantly surprised to receive 5,200 orders in just the first five weeks – more than predicted for the life of the machine. By late 1961, the 2000 installed in the USA were about one quarter of all electronic stored-program computers by all manufacturers, the number of installed 1401s peaked above 10,000 in the mid-1960s. In all, by the nearly half of all computer systems in the world were 1401-type systems. The system was marketed until February 1971, commonly used by small businesses as their primary data processing machines, the 1401 was also frequently used as an off-line peripheral controller for mainframe computers. In such installations, with an IBM7090 for example, the computers used only magnetic tape for input-output. It was the 1401 that transferred input data from slow peripherals to tape, and transferred output data from tape to the card punch and this allowed the mainframes throughput to not be limited by the speed of a card reader or printer. During the 1970s, IBM installed many 1401s in India and Pakistan where they were in use well into the 1980s, some of todays Indian and Pakistani software entrepreneurs started on these 1401s. The first computer in Pakistan, for example, was a 1401 installed at Pakistan International Airlines, each alphanumeric character in the 1401 was encoded by six bits, called B, A,8,4,2,1. The B, A bits were called zone bits and the 8,4,2,1 bits were called numeric bits, for digits 1 through 9, the bits B, A were zero, the digit BCD encoded in bits 8,4,2,1. Thus the letter A,12,1 in the punched card character code, was encoded B, A,1, encodings of punched card characters with two or more digit punches can be found in the Character and op codes table. IBM called the 1401s character code BCD, even though that term describes only the digit encoding. The 1401s alphanumeric collating sequence was compatible with the punched card collating sequence, associated with each memory location were two other bits, called C for odd parity check and M for word mark. Each memory location then, had the following bits, C B A8421 M The 1401 was available in six memory configurations,1400,2000,4000,8000,12000, each character was addressable, addresses ranging from 0 through 15999. A very small number of 1401s were expanded to 32,000 characters by special request, some operations used specific memory locations
32.
Magnetic-core memory
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Magnetic-core memory was the predominant form of random-access computer memory for 20 years between about 1955 and 1975. Such memory is often just called core memory, or, informally, Core uses tiny magnetic toroids, the cores, through which wires are threaded to write and read information. Each core represents one bit of information, the cores can be magnetized in two different ways and the bit stored in a core is zero or one depending on that cores magnetization direction. The process of reading the core causes the core to be reset to a zero, when not being read or written, the cores maintain the last value they had, even when power is turned off. Using smaller cores and wires, the density of core slowly increased. However, reaching this density required extremely careful manufacture, almost always carried out by hand in spite of repeated efforts to automate the process. The cost declined over this period from about $1 per bit to about 1 cent per bit, the introduction of the first semiconductor memory SRAM chips in the late 1960s began to erode the core market. The first successful DRAM, the Intel 1103 which arrived in quantity in 1972 at 1 cent per bit, improvements in semiconductor manufacturing led to rapid increases in storage and decreases in price that drove core from the market by around 1974. Although core memory is obsolete, any computer memory is still occasionally called core, in particular, the basic concept of using the square hysteresis loop of certain magnetic materials as a storage or switching device was known from the earliest days of computer development. Much of this knowledge had developed due to an understanding of transformers, the stable switching behavior was well known in the electrical engineering field, and its application in computer systems was immediate. For example, J. Presper Eckert and Jeffrey Chuan Chu had done some development work on the concept in 1945 at the Moore School during the ENIAC efforts. Frederick Viehe applied for patents on the use of transformers for building digital logic circuits in place of relay logic beginning in 1947. A patent on a fully developed core system was granted in 1947 and this development was little-known, however, and the mainstream development of core is normally associated with three independent teams. Substantial work in the field was carried out by the Shanghai-born American physicists An Wang and Way-Dong Woo, the name referred to the way that the magnetic field of the cores could be used to control the switching of current in electromechanical systems. Wang and Woo were working at Harvard Universitys Computation Laboratory at the time, Wang was able to patent the system on his own. The MIT Whirlwind computer required a fast memory system for real-time aircraft tracking use, at first, Williams tubes—a storage system based on cathode ray tubes—were used, but these devices were always temperamental and unreliable. William Papian of Project Whirlwind cited one of these efforts, Harvards Static Magnetic Delay Line, the first core memory of 32 x 32 x 16 bits was installed on Whirlwind in the summer of 1953. In April 2011, Forrester recalled, the Wang use of cores did not have any influence on my development of random-access memory, the Wang memory was expensive and complicated
33.
Index register
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An index register in a computers CPU is a processor register used for modifying operand addresses during the run of a program, typically for doing vector/array operations. The contents of a register is added to an immediate address to form the effective address of the actual data. Special instructions are provided to test the index register and, if the test fails, increments the index register by an immediate constant and branches. Some instruction sets allow more than one register to be used. While normally processors that allow an instruction to specify multiple index registers add the contents together, index registers, commonly known as a B-line in early British computers, were first used in the British Manchester Mark 1 computer, in 1949. In general, index registers became a part of computers during the technologys second generation. Most machines in the IBM 700/7000 mainframe series had them, starting with the IBM704 in 1954, though they were optional on some machines such as the IBM650. Early small machines with index registers include the AN/USQ-17, around 1960, the first microprocessor with a true index register appears to have been the Motorola 6800, and the similar MOS Technology 6502 made good use of two such registers. Early computers designed this way include the PDP-6 and the IBM System/360
34.
IBM Standard Modular System
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The Standard Modular System was a system of standard transistorized circuit boards and mounting racks developed by IBM in the late 1950s, originally for the IBM7030 Stretch. They were used throughout IBMs second generation computers, peripherals, the 7000 series, the 1400 series, SMS was superseded by Solid Logic Technology introduced with System/360 in 1964, however they remained in use with legacy systems through the 1970s. Many IBM peripheral devices that were part of System/360, but were adapted from second-generation designs and these included the 240x-series tape drives and controllers, the 2540 card reader/punch and 1403N1 printer, and the 2821 Integrated Control Unit for the 1403 and 2540. A few SMS cards used in System/360 peripheral devices even had SLT-type hybrid ICs mounted on them, SMS cards were constructed of individual discrete components mounted on single-sided paper-epoxy printed circuit boards. Single-width cards were 2.5 inches wide by 4.5 inches tall by 0.056 inches thick, double width cards were 5.375 inches wide by 4.5 inches tall, with two 16-pin gold plated edge connectors. Contacts were labeled A–R on the first edge connector, and S–Z, the cards were plugged into a card-cage back-plane and edge connector contacts connected to wire wrap pins. All interconnections were made with wire-wrapped connections, except for bus lines. Some card types could be customized via a cap that could be cut to change the circuit configuration. Card types with a program cap came with it precut for the standard configuration and this feature was intended to reduce the number of different card types a customer engineer had to carry with him to the customers site. The card type was a two to four letter code embossed on the card, if the card had a program cap the code was split into a two letter card type code and a two letter cap connection code. When SMS was originally developed, IBM anticipated a set of a couple hundred standard card types would be all that would be needed, making design, manufacture, unfortunately that proved far too optimistic as the number of different SMS card types soon grew to well over 2500. Part of the reason for the growth was that multiple digital logic families were implemented as well as analog circuits, to meet the requirements of the many different systems the cards were used in
