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135-555: The PDP-1 ( Programmed Data Processor-1 ) is the first computer in Digital Equipment Corporation 's PDP series and was first produced in 1959. It is famous for being the most important computer in the creation of hacker culture at the Massachusetts Institute of Technology , Bolt, Beranek and Newman and elsewhere. The PDP-1 is the original hardware for playing history's first game on
270-521: A binary system meant that Zuse's machines were easier to build and potentially more reliable, given the technologies available at that time. The Z3 was not itself a universal computer but could be extended to be Turing complete . Zuse's next computer, the Z4 , became the world's first commercial computer; after initial delay due to the Second World War, it was completed in 1950 and delivered to
405-632: A central processing unit (CPU) in the form of a microprocessor , together with some type of computer memory , typically semiconductor memory chips. The processing element carries out arithmetic and logical operations, and a sequencing and control unit can change the order of operations in response to stored information . Peripheral devices include input devices ( keyboards , mice , joysticks , etc.), output devices ( monitors , printers , etc.), and input/output devices that perform both functions (e.g. touchscreens ). Peripheral devices allow information to be retrieved from an external source, and they enable
540-462: A clock speed of 187 kilohertz ); consequently most arithmetic instructions take 10.7 microseconds (93,458 operations per second) because they use two memory cycles: the first to fetch the instruction, the second to fetch or store the data word. Signed numbers are represented in ones' complement . The PDP-1 has computing power roughly equivalent to a 1996 pocket organizer and a little less memory. The PDP-1 uses 2,700 transistors and 3,000 diodes. It
675-419: A keyboard , and computed and printed the results, demonstrating the feasibility of an electromechanical analytical engine. During the first half of the 20th century, many scientific computing needs were met by increasingly sophisticated analog computers, which used a direct mechanical or electrical model of the problem as a basis for computation . However, these were not programmable and generally lacked
810-524: A mass-production basis, which limited them to a number of specialized applications. At the University of Manchester , a team under the leadership of Tom Kilburn designed and built a machine using the newly developed transistors instead of valves. Their first transistorized computer and the first in the world, was operational by 1953 , and a second version was completed there in April 1955. However,
945-423: A minicomputer , Steve Russell 's Spacewar! The PDP-1 uses an 18-bit word size and has 4096 words as standard main memory (equivalent in bit size to 9,216 eight-bit bytes , but in character size to 12,388 bytes since the system actually divides an 18-bit word into three six-bit characters), upgradable to 65,536 words. The magnetic-core memory 's cycle time is 5.35 microseconds (corresponding roughly to
1080-429: A monolithic integrated circuit (IC) chip. Kilby's IC had external wire connections, which made it difficult to mass-produce. Noyce also came up with his own idea of an integrated circuit half a year later than Kilby. Noyce's invention was the first true monolithic IC chip. His chip solved many practical problems that Kilby's had not. Produced at Fairchild Semiconductor, it was made of silicon , whereas Kilby's chip
1215-652: A 1998 retrospective, it was the first working machine to contain all of the elements essential to a modern electronic computer. As soon as the Baby had demonstrated the feasibility of its design, a project began at the university to develop it into a practically useful computer, the Manchester Mark 1 . The Mark 1 in turn quickly became the prototype for the Ferranti Mark 1 , the world's first commercially available general-purpose computer. Built by Ferranti , it
1350-512: A Chip (SoCs) are complete computers on a microchip (or chip) the size of a coin. They may or may not have integrated RAM and flash memory . If not integrated, the RAM is usually placed directly above (known as Package on package ) or below (on the opposite side of the circuit board ) the SoC, and the flash memory is usually placed right next to the SoC. This is done to improve data transfer speeds, as
1485-487: A dollar are emitted as Federal Reserve Notes , disregarding these special cases: In the 16th century, Count Hieronymus Schlick of Bohemia began minting coins known as joachimstalers , named for Joachimstal , the valley in which the silver was mined. In turn, the valley's name is titled after Saint Joachim , whereby thal or tal , a cognate of the English word dale , is German for 'valley.' The joachimstaler
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#17327719449091620-757: A dollar, and dimes at 0.100 of a dollar. After the adoption of the United States Constitution , the U.S. dollar was defined by the Coinage Act of 1792 . It specified a "dollar" based on the Spanish milled dollar to contain 371 + 4 ⁄ 16 grains of fine silver, or 416.0 grains (26.96 g) of "standard silver" of fineness 371.25/416 = 89.24%; as well as an "eagle" to contain 247 + 4 ⁄ 8 grains of fine gold, or 270.0 grains (17.50 g) of 22 karat or 91.67% fine gold. Alexander Hamilton arrived at these numbers based on
1755-648: A few cases, U.S. coins) used in circulation. The monetary policy of the United States is conducted by the Federal Reserve System , which acts as the nation's central bank . As of February 10, 2021, currency in circulation amounted to US$ 2.10 trillion , $ 2.05 trillion of which is in Federal Reserve Notes (the remaining $ 50 billion is in the form of coins and older-style United States Notes ). As of September 20, 2023,
1890-545: A grain of pure, or four hundred and sixteen grains of standard silver. Section 20 of the Act designates the United States dollar as the unit of currency of the United States: [T]he money of account of the United States shall be expressed in dollars, or units...and that all accounts in the public offices and all proceedings in the courts of the United States shall be kept and had in conformity to this regulation. Unlike
2025-575: A limited extent" as money. Treasury Notes were again printed to help resolve the reduction in public revenues resulting from the Panic of 1837 and the Panic of 1857 , as well as to help finance the Mexican–American War and the Civil War . Paper money was issued again in 1862 without the backing of precious metals due to the Civil War . In addition to Treasury Notes, Congress in 1861 authorized
2160-403: A medieval European counting house , a checkered cloth would be placed on a table, and markers moved around on it according to certain rules, as an aid to calculating sums of money. The Antikythera mechanism is believed to be the earliest known mechanical analog computer , according to Derek J. de Solla Price . It was designed to calculate astronomical positions. It was discovered in 1901 in
2295-525: A much more general design, an analytical engine , was possible. The input of programs and data was to be provided to the machine via punched cards , a method being used at the time to direct mechanical looms such as the Jacquard loom . For output, the machine would have a printer, a curve plotter and a bell. The machine would also be able to punch numbers onto cards to be read in later. The engine would incorporate an arithmetic logic unit , control flow in
2430-529: A number of successes at breaking encrypted German military communications. The German encryption machine, Enigma , was first attacked with the help of the electro-mechanical bombes which were often run by women. To crack the more sophisticated German Lorenz SZ 40/42 machine, used for high-level Army communications, Max Newman and his colleagues commissioned Flowers to build the Colossus . He spent eleven months from early February 1943 designing and building
2565-442: A secondary storage medium for swapping programs and data in and out of core memory, without requiring manual intervention. For this purpose, DECtapes are far superior to paper tapes, in terms of reliability, durability, and speed. Early hard disks were expensive and notoriously unreliable; if available and working, they are used primarily for speed of swapping, and not for permanent file storage. The Type 30 Precision CRT display
2700-562: A sequence of sets of values. The whole machine was to be controlled by a read-only program, which was complete with provisions for conditional branching . He also introduced the idea of floating-point arithmetic . In 1920, to celebrate the 100th anniversary of the invention of the arithmometer , Torres presented in Paris the Electromechanical Arithmometer, which allowed a user to input arithmetic problems through
2835-678: A series of revisions to the gold peg was implemented, culminating in the Nixon Shock of August 15, 1971, which suddenly ended the convertibility of dollars to gold. The U.S. dollar has since floated freely on the foreign exchange markets . Congress continued to issue paper money after the Civil War, the latest of which is the Federal Reserve Note that was authorized by the Federal Reserve Act of 1913 . Since
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#17327719449092970-477: A sophisticated text-based program with some features specifically oriented toward the efficient coding of baroque music . Several hours of music were prepared for it, including Bach fugues , all of Mozart's Eine kleine Nachtmusik , the Ode to Joy movement concluding Beethoven's Symphony No. 9 , Christmas carols, and numerous popular songs. Only three PDP-1 computers are still known to exist, and all three are in
3105-460: A successful demonstration of its use in computing tables in 1906. In his work Essays on Automatics published in 1914, Leonardo Torres Quevedo wrote a brief history of Babbage's efforts at constructing a mechanical Difference Engine and Analytical Engine. The paper contains a design of a machine capable to calculate formulas like a x ( y − z ) 2 {\displaystyle a^{x}(y-z)^{2}} , for
3240-487: A treasury assay of the average fine silver content of a selection of worn Spanish dollars , which came out to be 371 grains. Combined with the prevailing gold-silver ratio of 15, the standard for gold was calculated at 371/15 = 24.73 grains fine gold or 26.98 grains 22K gold. Rounding the latter to 27.0 grains finalized the dollar's standard to 24.75 grains of fine gold or 24.75*15 = 371.25 grains = 24.0566 grams = 0.7735 troy ounces of fine silver. The same coinage act also set
3375-402: A universal Turing machine. Early computing machines had fixed programs. Changing its function required the re-wiring and re-structuring of the machine. With the proposal of the stored-program computer this changed. A stored-program computer includes by design an instruction set and can store in memory a set of instructions (a program ) that details the computation . The theoretical basis for
3510-577: A wide range of tasks. The term computer system may refer to a nominally complete computer that includes the hardware , operating system , software , and peripheral equipment needed and used for full operation; or to a group of computers that are linked and function together, such as a computer network or computer cluster . A broad range of industrial and consumer products use computers as control systems , including simple special-purpose devices like microwave ovens and remote controls , and factory devices like industrial robots . Computers are at
3645-427: Is a point plotting display device capable of addressing 1024 by 1024 addressable locations at a rate of 20,000 points per second. A special "Display One Point On CRT" instruction is used to build up images, which have to be refreshed many times per second. The CRT, which was originally developed for use in radar, is 16 inches (41 cm) in diameter and uses a long-persistence P7 phosphor . A light pen can be used with
3780-418: Is built mostly of DEC 1000-series System Building Blocks , using micro-alloy and micro-alloy diffused transistors with a rated switching speed of 5 MHz. The System Building Blocks are packaged into several 19-inch racks . The racks are themselves packaged into a single large mainframe case, with a hexagonal control panel containing switches and lights mounted to lie at table-top height at one end of
3915-488: Is equipped with online and offline printers that were based on IBM electric typewriter mechanisms, it is capable of what, in 1980s terminology, would be called " letter-quality printing " and therefore inspired TJ-2 , arguably the first word processor . The console typewriter, known as the Computeriter , was provided by Soroban Engineering . It is an adapted IBM Model B Electric typewriter mechanism, modified by
4050-454: Is one of the first words of Section 9, in which the term refers to the Spanish milled dollar , or the coin worth eight Spanish reales . In 1792, the U.S. Congress passed the Coinage Act , of which Section 9 authorized the production of various coins, including: Dollars or Units —each to be of the value of a Spanish milled dollar as the same is now current, and to contain three hundred and seventy-one grains and four sixteenth parts of
4185-460: Is that it is derived from the Pillars of Hercules on the Spanish coat of arms of the Spanish dollar . These Pillars of Hercules on the silver Spanish dollar coins take the form of two vertical bars ( || ) and a swinging cloth band in the shape of an S . Yet another explanation suggests that the dollar sign was formed from the capital letters U and S written or printed one on top of
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4320-463: Is the stored program , where all the instructions for computing are stored in memory. Von Neumann acknowledged that the central concept of the modern computer was due to this paper. Turing machines are to this day a central object of study in theory of computation . Except for the limitations imposed by their finite memory stores, modern computers are said to be Turing-complete , which is to say, they have algorithm execution capability equivalent to
4455-684: Is unreliable and prone to jamming, particularly when shifting case or changing ribbon color. Offline devices are typically Friden Flexowriters that have been specially built to operate with the FIO-DEC character coding used by the PDP-1. Like the console typewriter, these are built around a typing mechanism that is mechanically the same as an IBM Electric typewriter . However, Flexowriters are highly reliable and were often used for long unattended printing sessions. Flexowriters have electromechanical paper tape punches and readers which operate synchronously with
4590-619: The Antikythera wreck off the Greek island of Antikythera , between Kythera and Crete , and has been dated to approximately c. 100 BCE . Devices of comparable complexity to the Antikythera mechanism would not reappear until the fourteenth century. Many mechanical aids to calculation and measurement were constructed for astronomical and navigation use. The planisphere was a star chart invented by Abū Rayhān al-Bīrūnī in
4725-468: The Coinage Act of 1834 the dollar's fine gold equivalent was revised to 23.2 grains; it was slightly adjusted to 23.22 grains (1.505 g) in 1837 (gold-silver ratio ~16). The same act also resolved the difficulty in minting the "standard silver" of 89.24% fineness by revising the dollar's alloy to 412.5 grains, 90% silver, still containing 371.25 grains fine silver. Gold was also revised to 90% fineness: 25.8 grains gross, 23.22 grains fine gold. Following
4860-551: The Comstock Lode in the 1870s. This was the so-called "Crime of '73". The Gold Standard Act of 1900 repealed the U.S. dollar's historic link to silver and defined it solely as 23.22 grains (1.505 g) of fine gold (or $ 20.67 per troy ounce of 480 grains). In 1933, gold coins were confiscated by Executive Order 6102 under Franklin D. Roosevelt , and in 1934 the standard was changed to $ 35 per troy ounce fine gold, or 13.71 grains (0.888 g) per dollar. After 1968
4995-545: The Continental Congress resolved that the money unit of the United States, the dollar, would contain 375.64 grains of fine silver; on August 8, 1786, the Continental Congress continued that definition and further resolved that the money of account, corresponding with the division of coins, would proceed in a decimal ratio , with the sub-units being mills at 0.001 of a dollar, cents at 0.010 of
5130-526: The Dutch pioneered in modern-day New York in the 17th century the use and the counting of money in silver dollars in the form of German-Dutch reichsthalers and native Dutch leeuwendaalders ('lion dollars'), it was the ubiquitous Spanish American eight-real coin which became exclusively known as the dollar since the 18th century. The colloquialism buck(s) (much like the British quid for
5265-507: The E6B circular slide rule used for time and distance calculations on light aircraft. In the 1770s, Pierre Jaquet-Droz , a Swiss watchmaker , built a mechanical doll ( automaton ) that could write holding a quill pen. By switching the number and order of its internal wheels different letters, and hence different messages, could be produced. In effect, it could be mechanically "programmed" to read instructions. Along with two other complex machines,
5400-641: The ETH Zurich . The computer was manufactured by Zuse's own company, Zuse KG , which was founded in 1941 as the first company with the sole purpose of developing computers in Berlin. The Z4 served as the inspiration for the construction of the ERMETH , the first Swiss computer and one of the first in Europe. Purely electronic circuit elements soon replaced their mechanical and electromechanical equivalents, at
5535-630: The First World War , and displaced the pound sterling as the world's primary reserve currency by the Bretton Woods Agreement towards the end of the Second World War . The dollar is the most widely used currency in international transactions , and a free-floating currency . It is also the official currency in several countries and the de facto currency in many others, with Federal Reserve Notes (and, in
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5670-477: The MiSTer project as well, and binary image of paper tapes of the software exist in the bitsavers.org archives. Computer A computer is a machine that can be programmed to automatically carry out sequences of arithmetic or logical operations ( computation ). Modern digital electronic computers can perform generic sets of operations known as programs . These programs enable computers to perform
5805-740: The TX-2 , the successor to the TX-0 which had been developed at what Bell thought was a bargain price at the time, about US$ 3 million . At the same meeting, Jack Dennis said Ben Gurley's design for the PDP-1 was influenced by his work on the TX-0 display. The PDP-1 sold in basic form for US$ 120,000 (equivalent to US$ 1,223,519 in 2023). BBN's system was quickly followed by orders from Lawrence Livermore and Atomic Energy of Canada (AECL), and eventually 53 PDP-1s were delivered until production ended in 1969. All of these machines were still being actively used in 1970, and several were eventually saved. MIT's example
5940-561: The dollar , U.S. dollar , American dollar , or colloquially buck ) is the official currency of the United States and several other countries . The Coinage Act of 1792 introduced the U.S. dollar at par with the Spanish silver dollar , divided it into 100 cents , and authorized the minting of coins denominated in dollars and cents. U.S. banknotes are issued in the form of Federal Reserve Notes , popularly called greenbacks due to their predominantly green color. The U.S. dollar
6075-497: The microcomputer revolution in the 1970s. The speed, power, and versatility of computers have been increasing dramatically ever since then, with transistor counts increasing at a rapid pace ( Moore's law noted that counts doubled every two years), leading to the Digital Revolution during the late 20th and early 21st centuries. Conventionally, a modern computer consists of at least one processing element , typically
6210-401: The pound sterling ) is often used to refer to dollars of various nations, including the U.S. dollar. This term, dating to the 18th century, may have originated with the colonial leather trade, or it may also have originated from a poker term. Greenback is another nickname, originally applied specifically to the 19th-century Demand Note dollars, which were printed black and green on
6345-504: The "second generation" of computers. Compared to vacuum tubes, transistors have many advantages: they are smaller, and require less power than vacuum tubes, so give off less heat. Junction transistors were much more reliable than vacuum tubes and had longer, indefinite, service life. Transistorized computers could contain tens of thousands of binary logic circuits in a relatively compact space. However, early junction transistors were relatively bulky devices that were difficult to manufacture on
6480-525: The 1920s, Vannevar Bush and others developed mechanical differential analyzers. In the 1890s, the Spanish engineer Leonardo Torres Quevedo began to develop a series of advanced analog machines that could solve real and complex roots of polynomials , which were published in 1901 by the Paris Academy of Sciences . Charles Babbage , an English mechanical engineer and polymath , originated
6615-533: The CHM. AECL's computer was sent to Science North , but was later scrapped. The launch of the PDP-1 marked a radical shift in the philosophy of computer design: it is the first commercial computer that focuses on interaction with the user rather than just the efficient use of computer cycles. The first ever reference to malicious hacking is ' telephone hackers ' in MIT 's student newspaper, The Tech , of hackers tying up
6750-619: The Cambridge EDSAC of 1949, became operational in April 1951 and ran the world's first routine office computer job . The concept of a field-effect transistor was proposed by Julius Edgar Lilienfeld in 1925. John Bardeen and Walter Brattain , while working under William Shockley at Bell Labs , built the first working transistor , the point-contact transistor , in 1947, which was followed by Shockley's bipolar junction transistor in 1948. From 1955 onwards, transistors replaced vacuum tubes in computer designs, giving rise to
6885-529: The Constitution provides that "a regular Statement and Account of the Receipts and Expenditures of all public Money shall be published from time to time", which is further specified by Section 331 of Title 31 of the U.S. Code. The sums of money reported in the "Statements" are currently expressed in U.S. dollars, thus the U.S. dollar may be described as the unit of account of the United States. "Dollar"
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#17327719449097020-591: The EDVAC in 1945. The Manchester Baby was the world's first stored-program computer . It was built at the University of Manchester in England by Frederic C. Williams , Tom Kilburn and Geoff Tootill , and ran its first program on 21 June 1948. It was designed as a testbed for the Williams tube , the first random-access digital storage device. Although the computer was described as "small and primitive" by
7155-455: The ENIAC were six women, often known collectively as the "ENIAC girls". It combined the high speed of electronics with the ability to be programmed for many complex problems. It could add or subtract 5000 times a second, a thousand times faster than any other machine. It also had modules to multiply, divide, and square root. High speed memory was limited to 20 words (about 80 bytes). Built under
7290-582: The Federal Reserve estimated that the total amount of currency in circulation was approximately US$ 2.33 trillion . Article I , Section 8 of the U.S. Constitution provides that Congress has the power "[t]o coin money ." Laws implementing this power are currently codified in Title 31 of the U.S. Code , under Section 5112, which prescribes the forms in which the United States dollars should be issued. These coins are both designated in
7425-531: The MOS transistor, was invented at Bell Labs between 1955 and 1960 and was the first truly compact transistor that could be miniaturized and mass-produced for a wide range of uses. With its high scalability , and much lower power consumption and higher density than bipolar junction transistors, the MOSFET made it possible to build high-density integrated circuits . In addition to data processing, it also enabled
7560-455: The Scottish scientist Sir William Thomson in 1872 was of great utility to navigation in shallow waters. It used a system of pulleys and wires to automatically calculate predicted tide levels for a set period at a particular location. The differential analyser , a mechanical analog computer designed to solve differential equations by integration , used wheel-and-disc mechanisms to perform
7695-893: The Spanish milled dollar, the Continental Congress and the Coinage Act prescribed a decimal system of units to go with the unit dollar, as follows: the mill , or one-thousandth of a dollar; the cent , or one-hundredth of a dollar; the dime , or one-tenth of a dollar; and the eagle , or ten dollars. The current relevance of these units: The Spanish peso or dollar was historically divided into eight reales (colloquially, bits ) – hence pieces of eight . Americans also learned counting in non-decimal bits of 12 + 1 ⁄ 2 cents before 1857 when Mexican bits were more frequently encountered than American cents; in fact this practice survived in New York Stock Exchange quotations until 2001. In 1854, Secretary of
7830-540: The Treasury James Guthrie proposed creating $ 100, $ 50, and $ 25 gold coins, to be referred to as a union , half union , and quarter union , respectively, thus implying a denomination of 1 Union = $ 100. However, no such coins were ever struck, and only patterns for the $ 50 half union exist. When currently issued in circulating form, denominations less than or equal to a dollar are emitted as U.S. coins , while denominations greater than or equal to
7965-854: The Treasury to borrow $ 50 million in the form of Demand Notes , which did not bear interest but could be redeemed on demand for precious metals. However, by December 1861, the Union government's supply of specie was outstripped by demand for redemption and they were forced to suspend redemption temporarily. In February 1862 Congress passed the Legal Tender Act of 1862 , issuing United States Notes , which were not redeemable on demand and bore no interest, but were legal tender , meaning that creditors had to accept them at face value for any payment except for public debts and import tariffs. However, silver and gold coins continued to be issued, resulting in
8100-461: The Type 30 to pick points on the display. An optional character generator and hardware for line and curve generation are available. MIT hackers also used the PDP-1 for playing music in four-part harmony, using some special hardware – four flip-flops directly controlled by the processor (the audio signal is filtered with simple RC filters ). Music was prepared via Peter Samson 's Harmony Compiler ,
8235-493: The U.S. Although the ENIAC was similar to the Colossus, it was much faster, more flexible, and it was Turing-complete. Like the Colossus, a "program" on the ENIAC was defined by the states of its patch cables and switches, a far cry from the stored program electronic machines that came later. Once a program was written, it had to be mechanically set into the machine with manual resetting of plugs and switches. The programmers of
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#17327719449098370-531: The US, John Vincent Atanasoff and Clifford E. Berry of Iowa State University developed and tested the Atanasoff–Berry Computer (ABC) in 1942, the first "automatic electronic digital computer". This design was also all-electronic and used about 300 vacuum tubes, with capacitors fixed in a mechanically rotating drum for memory. During World War II, the British code-breakers at Bletchley Park achieved
8505-450: The United States and to supervise its banking system, particularly in the aftermath of the Panic of 1907 . For most of the post-war period, the U.S. government has financed its own spending by borrowing heavily from the dollar-lubricated global capital markets, in debts denominated in its own currency and at minimal interest rates. This ability to borrow heavily without facing a significant balance of payments crisis has been described as
8640-625: The United States until the Coinage Act of 1857 . In particular, colonists' familiarity with the Spanish two- real quarter peso was the reason for issuing a quasi-decimal 25-cent quarter dollar coin rather than a 20-cent coin. For the relationship between the Spanish dollar and the individual state colonial currencies, see Connecticut pound , Delaware pound , Georgia pound , Maryland pound , Massachusetts pound , New Hampshire pound , New Jersey pound , New York pound , North Carolina pound , Pennsylvania pound , Rhode Island pound , South Carolina pound , and Virginia pound . On July 6, 1785,
8775-402: The United States was a significant recipient of wartime gold inflows. After the United States emerged as an even stronger global superpower during the Second World War , the Bretton Woods Agreement of 1944 established the U.S. dollar as the world's primary reserve currency and the only post-war currency linked to gold. Despite all links to gold being severed in 1971, the dollar continues to be
8910-527: The addition of switches to detect key presses, and solenoids to activate the typebars . It uses a traditional typebar mechanism, not the "golfball" IBM Selectric typewriter mechanism, which was not introduced until the next year. Lettercase is selected by raising and lowering the massive type basket. The Soroban is equipped with a two-color inked ribbon (red and black), and the interface allows color selection. Programs commonly use color-coding to distinguish user input from machine responses. The Soroban mechanism
9045-898: The advent of the integrated circuit (IC). The idea of the integrated circuit was first conceived by a radar scientist working for the Royal Radar Establishment of the Ministry of Defence , Geoffrey W.A. Dummer . Dummer presented the first public description of an integrated circuit at the Symposium on Progress in Quality Electronic Components in Washington, D.C. , on 7 May 1952. The first working ICs were invented by Jack Kilby at Texas Instruments and Robert Noyce at Fairchild Semiconductor . Kilby recorded his initial ideas concerning
9180-521: The average Spanish dollar in circulation. The new U.S. silver dollar of 371.25 grains (24.057 g) therefore compared favorably and was received at par with the Spanish dollar for foreign payments, and after 1803 the United States Mint had to suspend making this coin out of its limited resources since it failed to stay in domestic circulation. It was only after Mexican independence in 1821 when their peso's fine silver content of 377.1 grains
9315-500: The backside, created by Abraham Lincoln to finance the North for the Civil War . It is still used to refer to the U.S. dollar (but not to the dollars of other countries). The term greenback is also used by the financial press in other countries, such as Australia , New Zealand , South Africa , and India . Other well-known names of the dollar as a whole in denominations include greenmail , green , and dead presidents ,
9450-647: The basic concept which underlies all electronic digital computers. By 1938, the United States Navy had developed an electromechanical analog computer small enough to use aboard a submarine . This was the Torpedo Data Computer , which used trigonometry to solve the problem of firing a torpedo at a moving target. During World War II similar devices were developed in other countries as well. Early digital computers were electromechanical ; electric switches drove mechanical relays to perform
9585-530: The best Arithmetician that euer [ sic ] breathed, and he reduceth thy dayes into a short number." This usage of the term referred to a human computer , a person who carried out calculations or computations . The word continued to have the same meaning until the middle of the 20th century. During the latter part of this period, women were often hired as computers because they could be paid less than their male counterparts. By 1943, most human computers were women. The Online Etymology Dictionary gives
9720-440: The buying and selling of goods. This allowed the value of things to remain fairly constant over time, except for the influx and outflux of gold and silver in the nation's economy. Though a Spanish dollar freshly minted after 1772 theoretically contained 417.7 grains of silver of fineness 130/144 (or 377.1 grains fine silver), reliable assays of the period in fact confirmed a fine silver content of 370.95 grains (24.037 g) for
9855-570: The calculation. These devices had a low operating speed and were eventually superseded by much faster all-electric computers, originally using vacuum tubes . The Z2 , created by German engineer Konrad Zuse in 1939 in Berlin , was one of the earliest examples of an electromechanical relay computer. In 1941, Zuse followed his earlier machine up with the Z3 , the world's first working electromechanical programmable , fully automatic digital computer. The Z3
9990-571: The collection of the Computer History Museum (CHM). One is the prototype formerly used at MIT, and the other two are production PDP-1C machines. One of the latter, serial number 55 (the last PDP-1 made) has been restored to working order, is on exhibit, and is demonstrated on two Saturdays every month. The demonstrations include: Software simulations of the PDP-1 exist in SIMH and MESS , hardware recreation through FPGA exists for
10125-565: The concept of a programmable computer. Considered the " father of the computer ", he conceptualized and invented the first mechanical computer in the early 19th century. After working on his difference engine he announced his invention in 1822, in a paper to the Royal Astronomical Society , titled "Note on the application of machinery to the computation of astronomical and mathematical tables". He also designed to aid in navigational calculations, in 1833 he realized that
10260-704: The core of general-purpose devices such as personal computers and mobile devices such as smartphones . Computers power the Internet , which links billions of computers and users. Early computers were meant to be used only for calculations. Simple manual instruments like the abacus have aided people in doing calculations since ancient times. 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
10395-414: The currency, a practice compared to the policies of European monarchs. The currency as we know it today did not get the faces they currently have until after the early 20th century; before that "heads" side of coinage used profile faces and striding, seated, and standing figures from Greek and Roman mythology and composite Native Americans. The last coins to be converted to profiles of historic Americans were
10530-499: The data signals do not have to travel long distances. Since ENIAC in 1945, computers have advanced enormously, with modern SoCs (such as the Snapdragon 865) being the size of a coin while also being hundreds of thousands of times more powerful than ENIAC, integrating billions of transistors, and consuming only a few watts of power. The first mobile computers were heavy and ran from mains power. The 50 lb (23 kg) IBM 5100
10665-515: The decision of the British Government to cease funding. Babbage's failure to complete the analytical engine can be chiefly attributed to political and financial difficulties as well as his desire to develop an increasingly sophisticated computer and to move ahead faster than anyone else could follow. Nevertheless, his son, Henry Babbage , completed a simplified version of the analytical engine's computing unit (the mill ) in 1888. He gave
10800-632: The depreciation of the newly printed notes through Gresham's law . In 1869, Supreme Court ruled in Hepburn v. Griswold that Congress could not require creditors to accept United States Notes, but overturned that ruling the next year in the Legal Tender Cases . In 1875, Congress passed the Specie Payment Resumption Act , requiring the Treasury to allow U.S. Notes to be redeemed for gold after January 1, 1879. Though
10935-668: The dime (1946), the half Dollar (1948), and the Dollar (1971). After the American Revolution , the Thirteen Colonies became independent . Freed from British monetary regulations, they each issued £sd paper money to pay for military expenses. The Continental Congress also began issuing "Continental Currency" denominated in Spanish dollars. For its value relative to states' currencies, see Early American currency . Continental currency depreciated badly during
11070-460: The direction of John Mauchly and J. Presper Eckert at the University of Pennsylvania, ENIAC's development and construction lasted from 1943 to full operation at the end of 1945. The machine was huge, weighing 30 tons, using 200 kilowatts of electric power and contained over 18,000 vacuum tubes, 1,500 relays, and hundreds of thousands of resistors, capacitors, and inductors. The principle of
11205-426: The discontinuation of all other types of notes (Gold Certificates in 1933, Silver Certificates in 1963, and United States Notes in 1971), U.S. dollar notes have since been issued exclusively as Federal Reserve Notes . The U.S. dollar first emerged as an important international reserve currency in the 1920s, displacing the British pound sterling as it emerged from the First World War relatively unscathed and since
11340-483: The doll is at the Musée d'Art et d'Histoire of Neuchâtel , Switzerland , and still operates. In 1831–1835, mathematician and engineer Giovanni Plana devised a Perpetual Calendar machine , which through a system of pulleys and cylinders could predict the perpetual calendar for every year from 0 CE (that is, 1 BCE) to 4000 CE, keeping track of leap years and varying day length. The tide-predicting machine invented by
11475-421: The dollar came under the gold standard de jure only after 1900, the bimetallic era was ended de facto when the Coinage Act of 1873 suspended the minting of the standard silver dollar of 412.5 Troy grains = 26.73 g; 0.859 ozt, the only fully legal tender coin that individuals could convert bullion into in unlimited (or Free silver ) quantities, and right at the onset of the silver rush from
11610-481: The early 11th century. The astrolabe was invented in the Hellenistic world in either the 1st or 2nd centuries BCE and is often attributed to Hipparchus . A combination of the planisphere and dioptra , the astrolabe was effectively an analog computer capable of working out several different kinds of problems in spherical astronomy . An astrolabe incorporating a mechanical calendar computer and gear -wheels
11745-545: The early 2000s. These smartphones and tablets run on a variety of operating systems and recently became the dominant computing device on the market. These are powered by System on a Chip (SoCs), which are complete computers on a microchip the size of a coin. Computers can be classified in a number of different ways, including: United States dollar The United States dollar ( symbol : $ ; currency code : USD ; also abbreviated US$ to distinguish it from other dollar-denominated currencies ; referred to as
11880-399: The early 20th century. The first digital electronic calculating machines were developed during World War II , both electromechanical and using thermionic valves . The first semiconductor transistors in the late 1940s were followed by the silicon -based MOSFET (MOS transistor) and monolithic integrated circuit chip technologies in the late 1950s, leading to the microprocessor and
12015-477: The exact definition of the term "microprocessor", it is largely undisputed that the first single-chip microprocessor was the Intel 4004 , designed and realized by Federico Faggin with his silicon-gate MOS IC technology, along with Ted Hoff , Masatoshi Shima and Stanley Mazor at Intel . In the early 1970s, MOS IC technology enabled the integration of more than 10,000 transistors on a single chip. System on
12150-508: The first Colossus. After a functional test in December 1943, Colossus was shipped to Bletchley Park, where it was delivered on 18 January 1944 and attacked its first message on 5 February. Colossus was the world's first electronic digital programmable computer. It used a large number of valves (vacuum tubes). It had paper-tape input and was capable of being configured to perform a variety of boolean logical operations on its data, but it
12285-482: The first PDP-1 to Bolt, Beranek and Newman (BBN) in November 1960, and it was formally accepted in early 1961. In September 1961, DEC donated the PDP-1 to MIT, where it was placed in the room next to its ancestor, the TX-0 computer, which was by then on indefinite loan from Lincoln Laboratory. In this setting, the PDP-1 quickly replaced the TX-0 as the favorite machine among the budding hacker culture , and served as
12420-725: The first attested use of computer in the 1640s, meaning 'one who calculates'; this is an "agent noun from compute (v.)". The Online Etymology Dictionary states that the use of the term to mean " 'calculating machine' (of any type) is from 1897." The Online Etymology Dictionary indicates that the "modern use" of the term, to mean 'programmable digital electronic computer' dates from "1945 under this name; [in a] theoretical [sense] from 1937, as Turing machine ". The name has remained, although modern computers are capable of many higher-level functions. Devices have been used to aid computation for thousands of years, mostly using one-to-one correspondence with fingers . The earliest counting device
12555-409: The form of conditional branching and loops , and integrated memory , making it the first design for a general-purpose computer that could be described in modern terms as Turing-complete . The machine was about a century ahead of its time. All the parts for his machine had to be made by hand – this was a major problem for a device with thousands of parts. Eventually, the project was dissolved with
12690-466: The integrated circuit in July 1958, successfully demonstrating the first working integrated example on 12 September 1958. In his patent application of 6 February 1959, Kilby described his new device as "a body of semiconductor material ... wherein all the components of the electronic circuit are completely integrated". However, Kilby's invention was a hybrid integrated circuit (hybrid IC), rather than
12825-411: The integration. In 1876, Sir William Thomson had already discussed the possible construction of such calculators, but he had been stymied by the limited output torque of the ball-and-disk integrators . In a differential analyzer, the output of one integrator drove the input of the next integrator, or a graphing output. The torque amplifier was the advance that allowed these machines to work. Starting in
12960-397: The latter of which referring to the deceased presidents pictured on most bills. Dollars in general have also been known as bones (e.g. "twenty bones" = $ 20). The newer designs, with portraits displayed in the main body of the obverse (rather than in cameo insets), upon paper color-coded by denomination, are sometimes referred to as bigface notes or Monopoly money . Piastre
13095-411: The lines with Harvard , configuring the PDP-1 to make free calls, war dialing and accumulating large phone bills. The PDP-1 uses fanfold punched paper tape as its primary storage medium. Unlike punched card decks, which could be sorted and re-ordered, paper tape is tedious to physically edit. This inspired the creation of text-editing programs such as Expensive Typewriter and TECO . Because it
13230-590: The machine did make use of valves to generate its 125 kHz clock waveforms and in the circuitry to read and write on its magnetic drum memory , so it was not the first completely transistorized computer. That distinction goes to the Harwell CADET of 1955, built by the electronics division of the Atomic Energy Research Establishment at Harwell . The metal–oxide–silicon field-effect transistor (MOSFET), also known as
13365-606: The mainframe. Above the control panel is the system's standard input/output solution, a punched tape reader and writer. The PDP-1 weighs about 730 kg (1,600 lb). The design of the PDP-1 is based on the pioneering TX-0 and TX-2 computers, designed and built at MIT Lincoln Laboratory . Benjamin Gurley was the lead engineer on the project. After showing a prototype at the Eastern Joint Computer Conference in December 1959, DEC delivered
13500-452: The modern computer was proposed by Alan Turing in his seminal 1936 paper, On Computable Numbers . Turing proposed a simple device that he called "Universal Computing machine" and that is now known as a universal Turing machine . He proved that such a machine is capable of computing anything that is computable by executing instructions (program) stored on tape, allowing the machine to be programmable. The fundamental concept of Turing's design
13635-401: The modern-day World Bank Group , establishing the infrastructure for conducting international payments and accessing the global capital markets using the U.S. dollar. The monetary policy of the United States is conducted by the Federal Reserve System , which acts as the nation's central bank . It was founded in 1913 under the Federal Reserve Act in order to furnish an elastic currency for
13770-403: The more famous Sir William Thomson. The art of mechanical analog computing reached its zenith with the differential analyzer , built by H. L. Hazen and Vannevar Bush at MIT starting in 1927. This built on the mechanical integrators of James Thomson and the torque amplifiers invented by H. W. Nieman. A dozen of these devices were built before their obsolescence became obvious. By the 1950s,
13905-517: The numerical amount, is used for the U.S. dollar (as well as for many other currencies). The sign was perhaps the result of a late 18th-century evolution of the scribal abbreviation p for the peso , the common name for the Spanish dollars that were in wide circulation in the New World from the 16th to the 19th centuries. The p and the s eventually came to be written over each other giving rise to $ . Another popular explanation
14040-561: The other. This theory, popularized by novelist Ayn Rand in Atlas Shrugged , does not consider the fact that the symbol was already in use before the formation of the United States. The U.S. dollar was introduced at par with the Spanish-American silver dollar (or Spanish peso , Spanish milled dollar , eight-real coin , piece-of-eight ). The latter was produced from the rich silver mine output of Spanish America ,
14175-584: The platform for a long list of computing innovations. This list includes one of the earliest digital video games, Spacewar! , the first text editor , the first word processor , the first interactive debugger , the first credible computer chess program, one of the very earliest time-sharing systems ( BBN Time-Sharing System ), and some of the earliest computerized music. At the Computer History Museum TX-0 alumni reunion in 1984, Gordon Bell said DEC's products developed directly from
14310-486: The practical use of MOS transistors as memory cell storage elements, leading to the development of MOS semiconductor memory , which replaced earlier magnetic-core memory in computers. The MOSFET led to the microcomputer revolution , and became the driving force behind the computer revolution . The MOSFET is the most widely used transistor in computers, and is the fundamental building block of digital electronics . The next great advance in computing power came with
14445-493: The results of operations to be saved and retrieved. It was not until the mid-20th century that the word acquired its modern definition; according to the Oxford English Dictionary , the first known use of the word computer was in a different sense, in a 1613 book called The Yong Mans Gleanings by the English writer Richard Brathwait : "I haue [ sic ] read the truest computer of Times, and
14580-487: The rise in the price of silver during the California Gold Rush and the disappearance of circulating silver coins, the Coinage Act of 1853 reduced the standard for silver coins less than $ 1 from 412.5 grains to 384 grains (24.9 g), 90% silver per 100 cents (slightly revised to 25.0 g, 90% silver in 1873). The Act also limited the free silver right of individuals to convert bullion into only one coin,
14715-591: The same time that digital calculation replaced analog. The engineer Tommy Flowers , working at the Post Office Research Station in London in the 1930s, began to explore the possible use of electronics for the telephone exchange . Experimental equipment that he built in 1934 went into operation five years later, converting a portion of the telephone exchange network into an electronic data processing system, using thousands of vacuum tubes . In
14850-572: The section as " legal tender " in payment of debts. The Sacagawea dollar is one example of the copper alloy dollar, in contrast to the American Silver Eagle which is pure silver . Section 5112 also provides for the minting and issuance of other coins, which have values ranging from one cent ( U.S. Penny ) to 100 dollars. These other coins are more fully described in Coins of the United States dollar . Article I, Section 9 of
14985-552: The silver dollar at the rate of 1 silver dollar to 1000 continental dollars. This resulted in the clause "No state shall... make anything but gold and silver coin a tender in payment of debts" being written into the United States Constitution article 1, section 10 . From implementation of the 1792 Mint Act to the 1900 implementation of the gold standard , the dollar was on a bimetallic silver-and-gold standard, defined as either 371.25 grains (24.056 g) of fine silver or 24.75 grains of fine gold (gold-silver ratio 15). Subsequent to
15120-477: The silver dollar of 412.5 grains; smaller coins of lower standard can only be produced by the United States Mint using its own bullion. Summary and links to coins issued in the 19th century: In order to finance the War of 1812 , Congress authorized the issuance of Treasury Notes , interest-bearing short-term debt that could be used to pay public dues. While they were intended to serve as debt, they did function "to
15255-490: The stored-program computer was laid out by Alan Turing in his 1936 paper. In 1945, Turing joined the National Physical Laboratory and began work on developing an electronic stored-program digital computer. His 1945 report "Proposed Electronic Calculator" was the first specification for such a device. John von Neumann at the University of Pennsylvania also circulated his First Draft of a Report on
15390-443: The success of digital electronic computers had spelled the end for most analog computing machines, but analog computers remained in use during the 1950s in some specialized applications such as education ( slide rule ) and aircraft ( control systems ). Claude Shannon 's 1937 master's thesis laid the foundations of digital computing, with his insight of applying Boolean algebra to the analysis and synthesis of switching circuits being
15525-510: The typewriter mechanism. Typing rates are about ten characters per second. A typical PDP-1 operating procedure is to output text to punched paper tape using the PDP-1's "high speed" (60-character-per-second) Teletype model BRPE punch, then to hand carry the tape to a Flexowriter for offline printing. In later years, DECtape drives were added to some PDP-1 systems, as a more convenient method of backing up programs and data, and to enable early time-sharing . This latter application usually requires
15660-414: The value of an eagle at 10 dollars, and the dollar at 1 ⁄ 10 eagle. It called for silver coins in denominations of 1, 1 ⁄ 2 , 1 ⁄ 4 , 1 ⁄ 10 , and 1 ⁄ 20 dollar, as well as gold coins in denominations of 1, 1 ⁄ 2 and 1 ⁄ 4 eagle. The value of gold or silver contained in the dollar was then converted into relative value in the economy for
15795-412: The versatility and accuracy of modern digital computers. The first modern analog computer was a tide-predicting machine , invented by Sir William Thomson (later to become Lord Kelvin) in 1872. The differential analyser , a mechanical analog computer designed to solve differential equations by integration using wheel-and-disc mechanisms, was conceptualized in 1876 by James Thomson , the elder brother of
15930-423: The war, giving rise to the famous phrase "not worth a continental". A primary problem was that monetary policy was not coordinated between Congress and the states, which continued to issue bills of credit. Additionally, neither Congress nor the governments of the several states had the will or the means to retire the bills from circulation through taxation or the sale of bonds. The currency was ultimately replaced by
16065-488: The world's foremost reserve currency for international trade to this day. The Bretton Woods Agreement of 1944 also defined the post-World War II monetary order and relations among modern-day independent states , by setting up a system of rules, institutions, and procedures to regulate the international monetary system . The agreement founded the International Monetary Fund and other institutions of
16200-406: Was a 16-transistor chip built by Fred Heiman and Steven Hofstein at RCA in 1962. General Microelectronics later introduced the first commercial MOS IC in 1964, developed by Robert Norman. Following the development of the self-aligned gate (silicon-gate) MOS transistor by Robert Kerwin, Donald Klein and John Sarace at Bell Labs in 1967, the first silicon-gate MOS IC with self-aligned gates
16335-625: Was an early example. Later portables such as the Osborne 1 and Compaq Portable were considerably lighter but still needed to be plugged in. The first laptops, such as the Grid Compass , removed this requirement by incorporating batteries – and with the continued miniaturization of computing resources and advancements in portable battery life, portable computers grew in popularity in the 2000s. The same developments allowed manufacturers to integrate computing resources into cellular mobile phones by
16470-537: Was built with 2000 relays , implementing a 22 bit word length that operated at a clock frequency of about 5–10 Hz . Program code was supplied on punched film while data could be stored in 64 words of memory or supplied from the keyboard. It was quite similar to modern machines in some respects, pioneering numerous advances such as floating-point numbers . Rather than the harder-to-implement decimal system (used in Charles Babbage 's earlier design), using
16605-511: Was delivered to the University of Manchester in February 1951. At least seven of these later machines were delivered between 1953 and 1957, one of them to Shell labs in Amsterdam . In October 1947 the directors of British catering company J. Lyons & Company decided to take an active role in promoting the commercial development of computers. Lyons's LEO I computer, modelled closely on
16740-443: Was developed by Federico Faggin at Fairchild Semiconductor in 1968. The MOSFET has since become the most critical device component in modern ICs. The development of the MOS integrated circuit led to the invention of the microprocessor , and heralded an explosion in the commercial and personal use of computers. While the subject of exactly which device was the first microprocessor is contentious, partly due to lack of agreement on
16875-825: Was developed in the late 16th century and found application in gunnery, surveying and navigation. The planimeter was a manual instrument to calculate the area of a closed figure by tracing over it with a mechanical linkage. The slide rule was invented around 1620–1630, by the English clergyman William Oughtred , shortly after the publication of the concept of the logarithm . It is a hand-operated analog computer for doing multiplication and division. As slide rule development progressed, added scales provided reciprocals, squares and square roots, cubes and cube roots, as well as transcendental functions such as logarithms and exponentials, circular and hyperbolic trigonometry and other functions . Slide rules with special scales are still used for quick performance of routine calculations, such as
17010-540: Was donated to The Computer Museum, Boston , and from there ended up at the Computer History Museum (CHM). A late version of Spacewar! on paper tape was still tucked into the case. PDP-1 #44 was found in a barn in Wichita, Kansas in 1988, apparently formerly owned by one of the many aviation companies in the area, and rescued for the Digital Historical Collection, also eventually ending up at
17145-412: Was firmly upheld, which the U.S. later had to compete with using a heavier 378.0 grains (24.49 g) Trade dollar coin . The early currency of the United States did not exhibit faces of presidents, as is the custom now; although today, by law, only the portrait of a deceased individual may appear on United States currency. In fact, the newly formed government was against having portraits of leaders on
17280-449: Was invented by Abi Bakr of Isfahan , Persia in 1235. Abū Rayhān al-Bīrūnī invented the first mechanical geared lunisolar calendar astrolabe, an early fixed- wired knowledge processing machine with a gear train and gear-wheels, c. 1000 AD . The sector , a calculating instrument used for solving problems in proportion, trigonometry , multiplication and division, and for various functions, such as squares and cube roots,
17415-465: Was later shortened to the German taler , a word that eventually found its way into many languages, including: tolar ( Czech , Slovak and Slovenian ); daler ( Danish and Swedish ); talar ( Polish ); dalar and daler ( Norwegian ); daler or daalder ( Dutch ); talari ( Ethiopian ); tallér ( Hungarian ); tallero ( Italian ); دولار ( Arabic ); and dollar ( English ). Though
17550-477: Was made of germanium . Noyce's monolithic IC was fabricated using the planar process , developed by his colleague Jean Hoerni in early 1959. In turn, the planar process was based on Carl Frosch and Lincoln Derick work on semiconductor surface passivation by silicon dioxide. Modern monolithic ICs are predominantly MOS ( metal–oxide–semiconductor ) integrated circuits, built from MOSFETs (MOS transistors). The earliest experimental MOS IC to be fabricated
17685-748: Was minted in Mexico City , Potosí (Bolivia), Lima (Peru), and elsewhere, and was in wide circulation throughout the Americas, Asia, and Europe from the 16th to the 19th centuries. The minting of machine-milled Spanish dollars since 1732 boosted its worldwide reputation as a trade coin and positioned it to be the model for the new currency of the United States . Even after the United States Mint commenced issuing coins in 1792, locally minted dollars and cents were less abundant in circulation than Spanish American pesos and reales ; hence Spanish, Mexican, and American dollars all remained legal tender in
17820-643: Was most likely a form of tally stick . Later record keeping aids throughout the Fertile Crescent included calculi (clay spheres, cones, etc.) which represented counts of items, likely 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 devices used in Babylonia as early as 2400 BCE. Since then, many other forms of reckoning boards or tables have been invented. In
17955-434: Was not Turing-complete. Nine Mk II Colossi were built (The Mk I was converted to a Mk II making ten machines in total). Colossus Mark I contained 1,500 thermionic valves (tubes), but Mark II with 2,400 valves, was both five times faster and simpler to operate than Mark I, greatly speeding the decoding process. The ENIAC (Electronic Numerical Integrator and Computer) was the first electronic programmable computer built in
18090-461: Was originally defined under a bimetallic standard of 371.25 grains (24.057 g) (0.7734375 troy ounces) fine silver or, from 1834 , 23.22 grains (1.505 g) fine gold, or $ 20.67 per troy ounce . The Gold Standard Act of 1900 linked the dollar solely to gold. From 1934, its equivalence to gold was revised to $ 35 per troy ounce . In 1971 all links to gold were repealed. The U.S. dollar became an important international reserve currency after
18225-662: Was the original French word for the U.S. dollar, used for example in the French text of the Louisiana Purchase . Though the U.S. dollar is called dollar in Modern French, the term piastre is still used among the speakers of Cajun French and New England French , as well as speakers in Haiti and other French-speaking Caribbean islands. Nicknames specific to denomination: The symbol $ , usually written before
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