1.
United States
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Forty-eight of the fifty states and the federal district are contiguous and located in North America between Canada and Mexico. The state of Alaska is in the northwest corner of North America, bordered by Canada to the east, the state of Hawaii is an archipelago in the mid-Pacific Ocean. The U. S. territories are scattered about the Pacific Ocean, the geography, climate and wildlife of the country are extremely diverse. At 3.8 million square miles and with over 324 million people, the United States is the worlds third- or fourth-largest country by area, third-largest by land area. It is one of the worlds most ethnically diverse and multicultural nations, paleo-Indians migrated from Asia to the North American mainland at least 15,000 years ago. European colonization began in the 16th century, the United States emerged from 13 British colonies along the East Coast. Numerous disputes between Great Britain and the following the Seven Years War led to the American Revolution. On July 4,1776, during the course of the American Revolutionary War, the war ended in 1783 with recognition of the independence of the United States by Great Britain, representing the first successful war of independence against a European power. The current constitution was adopted in 1788, after the Articles of Confederation, the first ten amendments, collectively named the Bill of Rights, were ratified in 1791 and designed to guarantee many fundamental civil liberties. During the second half of the 19th century, the American Civil War led to the end of slavery in the country. By the end of century, the United States extended into the Pacific Ocean. The Spanish–American War and World War I confirmed the status as a global military power. The end of the Cold War and the dissolution of the Soviet Union in 1991 left the United States as the sole superpower. The U. S. is a member of the United Nations, World Bank, International Monetary Fund, Organization of American States. The United States is a developed country, with the worlds largest economy by nominal GDP. It ranks highly in several measures of performance, including average wage, human development, per capita GDP. While the U. S. economy is considered post-industrial, characterized by the dominance of services and knowledge economy, the United States is a prominent political and cultural force internationally, and a leader in scientific research and technological innovations. In 1507, the German cartographer Martin Waldseemüller produced a map on which he named the lands of the Western Hemisphere America after the Italian explorer and cartographer Amerigo Vespucci
2.
Typewriter
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A typewriter is a mechanical or electromechanical machine for writing characters similar to those produced by printers movable type. A typewriter operates by means of keys that strike a ribbon to transmit ink or carbon impressions onto paper, typically, a single character is printed on each key press. The machine prints characters by making ink impressions of type elements similar to the used in movable type letterpress printing. At the end of the century, the term typewriter was also applied to a person who used a typing machine. After its invention in the 1860s, the quickly became an indispensable tool for practically all writing other than personal handwritten correspondence. It was widely used by writers, in offices. As with the automobile, telephone, and telegraph, a number of people contributed insights, historians have estimated that some form of typewriter was invented 52 times as thinkers tried to come up with a workable design. Some of the early typing instruments, In 1575 an Italian printmaker, Francesco Rampazzetto, invented the scrittura tattile, in 1714, Henry Mill obtained a patent in Britain for a machine that, from the patent, appears to have been similar to a typewriter. In 1802 Italian Agostino Fantoni developed a particular typewriter to enable his blind sister to write, in 1808 Italian Pellegrino Turri invented a typewriter. He also invented carbon paper to provide the ink for his machine, in 1823 Italian Pietro Conti di Cilavegna invented a new model of typewriter, the tachigrafo, also known as tachitipo. In 1829, William Austin Burt patented a machine called the Typographer which, the Science Museum describes it merely as the first writing mechanism whose invention was documented, but even that claim may be excessive, since Turris invention pre-dates it. Even in the hands of its inventor, this machine was slower than handwriting, Burt and his promoter John D. Sheldon never found a buyer for the patent, so the invention was never commercially produced, because the typographer used a dial, rather than keys, to select each character, it was called an index typewriter rather than a keyboard typewriter. Index typewriters of that era resemble the squeeze-style embosser from the 1960s more than they resemble the modern keyboard typewriter, by the mid-19th century, the increasing pace of business communication had created a need for mechanization of the writing process. Stenographers and telegraphers could take down information at rates up to 130 words per minute, from 1829 to 1870, many printing or typing machines were patented by inventors in Europe and America, but none went into commercial production. Charles Thurber developed multiple patents, of which his first in 1843 was developed as an aid to the blind, in 1855, the Italian Giuseppe Ravizza created a prototype typewriter called Cembalo scrivano o macchina da scrivere a tasti. It was a machine that let the user see the writing as it was typed. In 1861, Father Francisco João de Azevedo, a Brazilian priest, made his own typewriter with basic materials and tools, such as wood, in that same year the Brazilian emperor D
3.
UNIVAC
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UNIVAC is the name of a line of electronic digital stored-program computers starting with the products of the Eckert-Mauchly Computer Corporation. Later the name was applied to a division of the Remington Rand company, UNIVAC is an acronym for UNIVersal Automatic Computer. The BINAC, built by the Eckert-Mauchly Computer Corporation, was the first general-purpose computer for commercial use, the descendants of the later UNIVAC1107 continue today as products of the Unisys company. J. Presper Eckert and John Mauchly built the ENIAC at the University of Pennsylvanias Moore School of Electrical Engineering between 1943 and 1946 and that company first built a computer called BINAC for Northrop Aviation. Afterwards began the development of UNIVAC, UNIVAC was first intended for the Bureau of the Census, which paid for much of the development, and then was put in production. With the death of EMCCs chairman and chief financial backer Harry L. Straus in a crash on October 25,1949. Eckert and Mauchly now reported to Leslie Groves, the army general who had managed the Manhattan Project. The most famous UNIVAC product was the UNIVAC I mainframe computer of 1951 and this incident is particularly noteworthy because the computer predicted an Eisenhower landslide when traditional pollsters all called it for Adlai Stevenson. The numbers were so skewed that CBSs news boss in New York, Mickelson, decided the computer was in error, instead they showed some staged theatrics that suggested the computer was not responsive, and announced it was predicting 8-7 odds for an Eisenhower win. Remington Rand had its own calculating machine lab in Norwalk, Connecticut and this severely annoyed those who had been with ERA and with the Norwalk laboratory. In 1955 Remington Rand merged with Sperry Corporation to become Sperry Rand, the UNIVAC division of Remington Rand was renamed the Univac division of Sperry Rand. General Douglas MacArthur was chosen to head the company, in the 1970s, after GE sold its computer business to Honeywell and RCA sold its to Univac, the analogy to the seven dwarfs became less apt and the remaining small firms became known as the BUNCH. To assist corporate identity the name was changed to Sperry Univac, along with Sperry Remington, Sperry New Holland, in 1978 Sperry Rand, an old fashioned conglomerate of disharmonious divisions, decided to concentrate on its computing interests and unrelated divisions were sold. The company dropped the Rand from its title and reverted to Sperry Corporation, in 1986, Sperry Corporation merged with Burroughs Corporation to become Unisys. Unisys continues to design and manufacture enterprise class computers with the ClearPath, in the course of its history, UNIVAC produced a number of separate model ranges. Early UNIVAC1100 series models were vacuum tube computers, the original model range was the UNIVAC I, the second commercial computer made in the United States. The main memory consisted of tanks of liquid mercury implementing delay line memory, the first machine was delivered on 31 March 1951. The UNIVAC II was an improvement to the UNIVAC I that UNIVAC first delivered in 1958 and it was fully compatible with existing UNIVAC I programs for both code and data
4.
Park Avenue
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Park Avenue is a wide New York City boulevard which carries north and southbound traffic in the borough of Manhattan, and is also a wide one-way pair in the Bronx. For most of the length in Manhattan, it runs parallel to Madison Avenue to the west. Park Avenues entire length was formerly called Fourth Avenue, the title applies to the section between the Bowery and 14th Street. Meanwhile, the section between 14th and 17th Street is called Union Square East, and between 17th and 32nd Streets, the name Park Avenue South is used, in the Bronx, Park Avenue runs in several segments between the Major Deegan Expressway and Fordham Road. Park Avenue was originally known as Fourth Avenue and carried the tracks of the New York, the railroad originally ran through an open cut through Murray Hill, which was covered with grates and grass between 34th and 40th Street in the early 1850s. A section of park was later renamed Park Avenue in 1860. When Grand Central Depot was opened in the 1870s, the tracks between 56th and 93rd Streets were sunk out of sight and, in 1888, Park Avenue was extended to north of Grand Central. In 1936 the elevated Park Avenue Viaduct was built around the station to allow traffic to pass unimpeded. In October 1937, a part of the Murray Hill Tunnel was reopened for road traffic, efforts to promote a Grand Park Avenue Expressway to Grand Concourse in the Bronx were unavailing. A tradition was introduced in 1945 as a memorial to American soldiers killed in action, on May 5,1959, the New York City Council voted 20–1 to change the name of Fourth Avenue between 17th and 32nd Streets to Park Avenue South. In 1963, the Pan Am Building, straddling Park Avenue atop Grand Central Terminal, was built between the automotive viaducts, on March 12,2014, two apartment buildings near 116th Street,1644 and 1646 Park Avenue, were destroyed in a gas explosion. Eight people were killed and many others were injured, the road that becomes Park Avenue originates as the Bowery. From Cooper Square at 8th Street to Union Square at 14th Street, it is known as Fourth Avenue, at 14th Street, it turns slightly northeast to align with other avenues drawn up in the Commissioners Plan of 1811. From 17th Street to 32nd Street, it is known as Park Avenue South, above 32nd Street, for the remainder of its distance, it is known as Park Avenue, a 140-foot-wide boulevard. Between 33rd Street and 40th Street, the northbound lane descends into the Murray Hill Tunnel. The bridge, one of two structures in Manhattan known as the Park Avenue Viaduct, returns to level at 46th Street after going through the Helmsley Building. The IRT Lexington Avenue Line runs under this portion of the street, once the line reaches Grand Central – 42nd Street, it shifts east to Lexington Avenue. From 47th to 97th Streets, Metro-North Railroad tracks run in a tunnel underneath Park Avenue, in the 1920s the portion of Park Avenue from Grand Central Terminal to 96th Street saw extensive apartment building construction
5.
New York City
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The City of New York, often called New York City or simply New York, is the most populous city in the United States. With an estimated 2015 population of 8,550,405 distributed over an area of about 302.6 square miles. Located at the tip of the state of New York. Home to the headquarters of the United Nations, New York is an important center for international diplomacy and has described as the cultural and financial capital of the world. Situated on one of the worlds largest natural harbors, New York City consists of five boroughs, the five boroughs – Brooklyn, Queens, Manhattan, The Bronx, and Staten Island – were consolidated into a single city in 1898. In 2013, the MSA produced a gross metropolitan product of nearly US$1.39 trillion, in 2012, the CSA generated a GMP of over US$1.55 trillion. NYCs MSA and CSA GDP are higher than all but 11 and 12 countries, New York City traces its origin to its 1624 founding in Lower Manhattan as a trading post by colonists of the Dutch Republic and was named New Amsterdam in 1626. The city and its surroundings came under English control in 1664 and were renamed New York after King Charles II of England granted the lands to his brother, New York served as the capital of the United States from 1785 until 1790. It has been the countrys largest city since 1790, the Statue of Liberty greeted millions of immigrants as they came to the Americas by ship in the late 19th and early 20th centuries and is a symbol of the United States and its democracy. In the 21st century, New York has emerged as a node of creativity and entrepreneurship, social tolerance. Several sources have ranked New York the most photographed city in the world, the names of many of the citys bridges, tapered skyscrapers, and parks are known around the world. Manhattans real estate market is among the most expensive in the world, Manhattans Chinatown incorporates the highest concentration of Chinese people in the Western Hemisphere, with multiple signature Chinatowns developing across the city. Providing continuous 24/7 service, the New York City Subway is one of the most extensive metro systems worldwide, with 472 stations in operation. Over 120 colleges and universities are located in New York City, including Columbia University, New York University, and Rockefeller University, during the Wisconsinan glaciation, the New York City region was situated at the edge of a large ice sheet over 1,000 feet in depth. The ice sheet scraped away large amounts of soil, leaving the bedrock that serves as the foundation for much of New York City today. Later on, movement of the ice sheet would contribute to the separation of what are now Long Island and Staten Island. The first documented visit by a European was in 1524 by Giovanni da Verrazzano, a Florentine explorer in the service of the French crown and he claimed the area for France and named it Nouvelle Angoulême. Heavy ice kept him from further exploration, and he returned to Spain in August and he proceeded to sail up what the Dutch would name the North River, named first by Hudson as the Mauritius after Maurice, Prince of Orange
6.
Skyscraper
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A skyscraper is a tall, continuously habitable building having multiple floors. When the term was used in the 1880s it described a building of 10 to 20 floors. Mostly designed for office, commercial and residential uses, a skyscraper can also be called a high-rise, for buildings above a height of 300 m, the term supertall can be used, while skyscrapers reaching beyond 600 m are classified as megatall. One common feature of skyscrapers is having a steel framework that supports curtain walls and these curtain walls either bear on the framework below or are suspended from the framework above, rather than resting on load-bearing walls of conventional construction. Some early skyscrapers have a frame that enables the construction of load-bearing walls taller than of those made of reinforced concrete. Modern skyscrapers walls are not load-bearing, and most skyscrapers are characterized by surface areas of windows made possible by steel frames. However, skyscrapers can have curtain walls that mimic conventional walls with a surface area of windows. Modern skyscrapers often have a structure, and are designed to act like a hollow cylinder to resist wind, seismic. To appear more slender, allow less wind exposure, and transmit more daylight to the ground, many skyscrapers have a design with setbacks, a relatively big building may be considered a skyscraper if it protrudes well above its built environment and changes the overall skyline. The maximum height of structures has progressed historically with building methods and technologies, the Burj Khalifa is currently the tallest building in the world. High-rise buildings are considered shorter than skyscrapers, the first steel-frame skyscraper was the Home Insurance Building in Chicago, Illinois in 1885. Even the scholars making the argument find it to be purely academic and this definition was based on the steel skeleton—as opposed to constructions of load-bearing masonry, which passed their practical limit in 1891 with Chicagos Monadnock Building. What is the characteristic of the tall office building. The force and power of altitude must be in it, the glory and it must be every inch a proud and soaring thing, rising in sheer exaltation that from bottom to top it is a unit without a single dissenting line. Some structural engineers define a highrise as any vertical construction for which wind is a significant load factor than earthquake or weight. Note that this criterion fits not only high-rises but some other tall structures, the word skyscraper often carries a connotation of pride and achievement. A loose convention of some in the United States and Europe draws the limit of a skyscraper at 150 m or 490 ft. The tallest building in ancient times was the 146 m Great Pyramid of Giza in ancient Egypt and it was not surpassed in height for thousands of years, the 14th century AD Lincoln Cathedral being conjectured by many to have exceeded it
7.
Rowayton
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Rowayton is an affluent coastal village within Norwalk, Connecticut, roughly 40 miles from New York City. According to Forbes magazine, the 2010 median home price was $1,674,964. In 2013, the Hartford Business Journal ranked Rowayton as the third wealthiest ZIP code in the state of Connecticut, the Rowayton station on the New Haven line of the Metro-North Railroad is located within the community, as is an elementary school. The Rowayton coastline has been a source of inspiration for centuries, john Frederick Kensett, a famous nineteenth-century landscape painter of the Hudson School, frequently painted this seascape in his later life. This tradition has carried on in an active local arts scene. Rowayton is home to a host of beaches, three of which—Roton Point, Bayley Beach, and an enclave of Wee Burn Country Club—share a common history. In the early 20th century, the properties of all three made up the Roton Point Amusement Park, a boat landing attached to Sunset Rock, just to the West of Belle Island, allowed steam boats to bring day-trippers from New York City to the park. A trolley ran from both Darien and Norwalk, arriving at the Park via Highland Avenue and over present-day Langdon Preserve, located across from Farm Creek. At the Amusement Park, amenities included a house, a picnic grove. The former Rock Ledge estate at 33 and 40-42 Highland Avenue was added to the National Register of Historic Places in 1977. In 1910, James A. Farrell, later president of the United States Steel Corporation, built a Tudor revival mansion, the estate was later bought by the Remington Rand Corporation, developers of the UNIVAC computer, which merged with Sperry Corporation to form Sperry Rand. Since 1966, the Farrell family stables have been converted to the Rowayton Community Center, in 1964, part of the estate was purchased by the Thomas School for girls, a day and boarding school founded by Mabel Thomas in 1922. The school later merged with private schools in the area. The school is now co-educational and located in Stamford, Connecticut, the mansion and attached office building were previously owned by Hewitt Associates. Currently, the house of the estate is home to Graham Capital. k. a
8.
Leslie Groves
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Lieutenant General Leslie Richard Groves Jr. As the son of a United States Army chaplain, Groves lived at a number of Army posts during his childhood and he graduated fourth in his class at the United States Military Academy at West Point in 1918 and was commissioned into the US Army Corps of Engineers. In 1929, he went to Nicaragua as part of an expedition whose purpose was to conduct a survey for the Inter-Oceanic Nicaragua Canal. Following the 1931 Nicaragua earthquake, Groves took over responsibility for Managuas water supply system, in August 1941, he was given responsibility for the gigantic office complex to house the War Departments 40,000 staff which would ultimately become the Pentagon. In September 1942, Groves took charge of the Manhattan Project and he was involved in most aspects of the atomic bombs development. He participated in the selection of sites for research and production at Oak Ridge, Tennessee, Los Alamos, New Mexico, and Hanford, Washington. After the war, Groves remained in charge of the Manhattan Project until responsibility for nuclear weapons production was handed over to the United States Atomic Energy Commission in 1947. He then headed the Armed Forces Special Weapons Project, which had created to control the military aspects of nuclear weapons. He was given a dressing down by the Chief of Staff of the United States Army, General of the Army Dwight D. Eisenhower, three days later, Groves announced his intention to leave the Army. He was promoted to lieutenant general just before his retirement on 29 February 1948 in recognition of his leadership of the bomb program, by a special Act of Congress, his date of rank was backdated to 16 July 1945, the date of the Trinity nuclear test. He went on to become a vice-president at Sperry Rand, Leslie Richard Groves Jr. was born in Albany, New York, on 17 August 1896, the third son of four children of a pastor, Leslie Richard Groves Sr. and his wife Gwen née Griffith. He was posted to the 14th Infantry at Vancouver Barracks in Washington in 1897, following the outbreak of the Spanish–American War in 1898, Chaplain Groves was sent to Cuba with the 8th Infantry. On returning to Vancouver Barracks, he was ordered to rejoin the 14th Infantry in the Philippines, service in the Philippine–American War, the 14th Infantry returned to the United States in 1901 and moved to Fort Snelling, Minnesota. The family relocated to there from Vancouver, then moved to Fort Hancock, New Jersey, the next year, Chaplain Groves was hospitalized with tuberculosis at Fort Bayard in 1905. He decided to settle in southern California and bought a house in Altadena and his next posting was to Fort Apache, Arizona. The family spent their summers there and returned to Altadena where the children attended school, in 1911, Chaplain Groves was ordered to return to the 14th Infantry, which was now stationed at Fort William Henry Harrison, Montana. Here young Dick Groves met Grace Wilson, the daughter of Colonel Richard Hulbert Wilson, in 1913, the 14th Infantry moved once more, this time to Fort Lawton, Washington. Dick Groves entered Queen Anne High School in nearby Seattle in 1913, in September of that year, he commenced his final year of high school, and also enrolled at the University of Washington
9.
Manhattan Project
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The Manhattan Project was a research and development undertaking during World War II that produced the first nuclear weapons. It was led by the United States with the support of the United Kingdom, from 1942 to 1946, the project was under the direction of Major General Leslie Groves of the U. S. Army Corps of Engineers. Nuclear physicist J. Robert Oppenheimer was the director of the Los Alamos Laboratory that designed the actual bombs, the Army component of the project was designated the Manhattan District, Manhattan gradually superseded the official codename, Development of Substitute Materials, for the entire project. Along the way, the project absorbed its earlier British counterpart, the Manhattan Project began modestly in 1939, but grew to employ more than 130,000 people and cost nearly US $2 billion. Over 90% of the cost was for building factories and to produce material, with less than 10% for development. Research and production took place at more than 30 sites across the United States, the United Kingdom, two types of atomic bombs were developed concurrently during the war, a relatively simple gun-type fission weapon and a more complex implosion-type nuclear weapon. Chemically identical to the most common isotope, uranium-238, and with almost the same mass, three methods were employed for uranium enrichment, electromagnetic, gaseous and thermal. Most of this work was performed at the Clinton Engineer Works at Oak Ridge, in parallel with the work on uranium was an effort to produce plutonium. The plutonium was then separated from the uranium. The Fat Man implosion-type weapon was developed in a concerted design, the project was also charged with gathering intelligence on the German nuclear weapon project. Through Operation Alsos, Manhattan Project personnel served in Europe, sometimes behind enemy lines, where they gathered nuclear materials and documents, despite the Manhattan Projects tight security, Soviet atomic spies still penetrated the program. The first nuclear device ever detonated was a bomb at the Trinity test, conducted at New Mexicos Alamogordo Bombing. Little Boy and Fat Man bombs were used a later in the atomic bombings of Hiroshima and Nagasaki. It maintained control over American atomic weapons research and production until the formation of the United States Atomic Energy Commission in January 1947, there were fears that a German atomic bomb project would develop one first, especially among scientists who were refugees from Nazi Germany and other fascist countries. In August 1939, Hungarian-born physicists Leó Szilárd and Eugene Wigner drafted the Einstein–Szilárd letter and it urged the United States to take steps to acquire stockpiles of uranium ore and accelerate the research of Enrico Fermi and others into nuclear chain reactions. They had it signed by Albert Einstein and delivered to President Franklin D. Roosevelt, Roosevelt called on Lyman Briggs of the National Bureau of Standards to head the Advisory Committee on Uranium to investigate the issues raised by the letter. Briggs held a meeting on 21 October 1939, which was attended by Szilárd, Wigner, the committee reported back to Roosevelt in November that uranium would provide a possible source of bombs with a destructiveness vastly greater than anything now known. The Advisory Committee on Uranium became the National Defense Research Committee Committee on Uranium when that organization was formed on 27 June 1940, Briggs proposed that the spend $167,000 on research into uranium, particularly the uranium-235 isotope, and the recently discovered plutonium
10.
National Register of Historic Places
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The National Register of Historic Places is the United States federal governments official list of districts, sites, buildings, structures, and objects deemed worthy of preservation. The passage of the National Historic Preservation Act in 1966 established the National Register, of the more than one million properties on the National Register,80,000 are listed individually. The remainder are contributing resources within historic districts, each year approximately 30,000 properties are added to the National Register as part of districts or by individual listings. For most of its history the National Register has been administered by the National Park Service and its goals are to help property owners and interest groups, such as the National Trust for Historic Preservation, coordinate, identify, and protect historic sites in the United States. While National Register listings are mostly symbolic, their recognition of significance provides some financial incentive to owners of listed properties, protection of the property is not guaranteed. During the nomination process, the property is evaluated in terms of the four criteria for inclusion on the National Register of Historic Places, the application of those criteria has been the subject of criticism by academics of history and preservation, as well as the public and politicians. Occasionally, historic sites outside the proper, but associated with the United States are also listed. Properties can be nominated in a variety of forms, including individual properties, historic districts, the Register categorizes general listings into one of five types of properties, district, site, structure, building, or object. National Register Historic Districts are defined geographical areas consisting of contributing and non-contributing properties, some properties are added automatically to the National Register when they become administered by the National Park Service. These include National Historic Landmarks, National Historic Sites, National Historical Parks, National Military Parks/Battlefields, National Memorials, on October 15,1966, the Historic Preservation Act created the National Register of Historic Places and the corresponding State Historic Preservation Offices. Initially, the National Register consisted of the National Historic Landmarks designated before the Registers creation, approval of the act, which was amended in 1980 and 1992, represented the first time the United States had a broad-based historic preservation policy. To administer the newly created National Register of Historic Places, the National Park Service of the U. S. Department of the Interior, hartzog, Jr. established an administrative division named the Office of Archeology and Historic Preservation. Hartzog charged OAHP with creating the National Register program mandated by the 1966 law, ernest Connally was the Offices first director. Within OAHP new divisions were created to deal with the National Register, the first official Keeper of the Register was William J. Murtagh, an architectural historian. During the Registers earliest years in the late 1960s and early 1970s, organization was lax and SHPOs were small, understaffed, and underfunded. A few years later in 1979, the NPS history programs affiliated with both the U. S. National Parks system and the National Register were categorized formally into two Assistant Directorates. Established were the Assistant Directorate for Archeology and Historic Preservation and the Assistant Directorate for Park Historic Preservation, from 1978 until 1981, the main agency for the National Register was the Heritage Conservation and Recreation Service of the United States Department of the Interior. In February 1983, the two assistant directorates were merged to promote efficiency and recognize the interdependency of their programs, jerry L. Rogers was selected to direct this newly merged associate directorate
11.
ENIAC
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ENIAC was amongst the earliest electronic general-purpose computers made. It was Turing-complete, digital, and could solve a large class of problems through reprogramming. ENIAC was formally dedicated at the University of Pennsylvania on February 15,1946 and was heralded as a Giant Brain by the press. This combination of speed and programmability allowed for thousands more calculations for problems, ENIACs design and construction was financed by the United States Army, Ordnance Corps, Research and Development Command, led by Major General Gladeon M. Barnes. The total cost was about $487,000, equivalent to $6,740,000 in 2016, ENIAC was designed by John Mauchly and J. Presper Eckert of the University of Pennsylvania, U. S. The team of design engineers assisting the development included Robert F. Shaw, Jeffrey Chuan Chu, Thomas Kite Sharpless, Frank Mural, Arthur Burks, Harry Huskey, in 1946, the researchers resigned from the University of Pennsylvania and formed the Eckert-Mauchly Computer Corporation. ENIAC was a computer, composed of individual panels to perform different functions. Twenty of these modules were accumulators which could not only add and subtract, numbers were passed between these units across several general-purpose buses. In order to achieve its high speed, the panels had to send and receive numbers, compute, save the answer and trigger the next operation, all without any moving parts. Key to its versatility was the ability to branch, it could trigger different operations, depending on the sign of a computed result. By the end of its operation in 1955, ENIAC contained 17,468 vacuum tubes,7200 crystal diodes,1500 relays,70,000 resistors,10,000 capacitors and approximately 5,000,000 hand-soldered joints. It weighed more than 30 short tons, was roughly 2.4 m ×0.9 m ×30 m in size, occupied 167 m2 and this power requirement led to the rumor that whenever the computer was switched on, lights in Philadelphia dimmed. Input was possible from an IBM card reader and an IBM card punch was used for output and these cards could be used to produce printed output offline using an IBM accounting machine, such as the IBM405. While ENIAC had no system to store memory in its inception, in 1953, a 100-word magnetic-core memory built by the Burroughs Corporation was added to ENIAC. ENIAC used ten-position ring counters to store digits, each digit required 36 vacuum tubes,10 of which were the dual triodes making up the flip-flops of the ring counter. ENIAC had 20 ten-digit signed accumulators, which used tens complement representation and it was possible to connect several accumulators to run simultaneously, so the peak speed of operation was potentially much higher, due to parallel operation. The other 9 units in ENIAC were the Initiating Unit, the Cycling Unit, the Master Programmer, the Reader, the Printer, the references by Rojas and Hashagen give more details about the times for operations, which differ somewhat from those stated above. The basic machine cycle was 200 microseconds, or 5,000 cycles per second for operations on the 10-digit numbers, in one of these cycles, ENIAC could write a number to a register, read a number from a register, or add/subtract two numbers
12.
Computer
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A computer is a device that can be instructed to carry out an arbitrary set of arithmetic or logical operations automatically. The ability of computers to follow a sequence of operations, called a program, such computers are used as control systems for a very wide variety of industrial and consumer devices. The Internet is run on computers and it millions of other computers. Since ancient times, simple manual devices like the abacus aided people in doing calculations, early in the Industrial Revolution, some mechanical devices were built to automate long tedious tasks, such as guiding patterns for looms. More sophisticated electrical machines did specialized analog calculations in the early 20th century, the first digital electronic calculating machines were developed during World War II. The speed, power, and versatility of computers has increased continuously and dramatically since then, conventionally, a modern computer consists of at least one processing element, typically a central processing unit, and some form of memory. The processing element carries out arithmetic and logical operations, and a sequencing, peripheral devices include input devices, output devices, and input/output devices that perform both functions. Peripheral devices allow information to be retrieved from an external source and this usage of the term referred to a person who carried out calculations or computations. The word continued with the same meaning until the middle of the 20th century, from the end of the 19th century the word began to take on its more familiar meaning, a machine that carries out computations. The Online Etymology Dictionary gives the first attested use of computer in the 1640s, one who calculates, the Online Etymology Dictionary states that the use of the term to mean calculating machine is from 1897. The Online Etymology Dictionary indicates that the use of the term. 1945 under this name, theoretical from 1937, as Turing machine, devices have been used to aid computation for thousands of years, mostly using one-to-one correspondence with fingers. The earliest counting device was probably a form of tally stick, later record keeping aids throughout the Fertile Crescent included calculi which represented counts of items, probably livestock or grains, sealed in hollow unbaked clay containers. The use of counting rods is one example, the abacus was initially used for arithmetic tasks. The Roman abacus was developed from used in Babylonia as early as 2400 BC. Since then, many forms of reckoning boards or tables have been invented. In a medieval European counting house, a checkered cloth would be placed on a table, the Antikythera mechanism is believed to be the earliest mechanical analog computer, according to Derek J. de Solla Price. It was designed to calculate astronomical positions and it was discovered in 1901 in the Antikythera wreck off the Greek island of Antikythera, between Kythera and Crete, and has been dated to circa 100 BC
