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Harvard Mark II
The Harvard Mark II, also known as the Aiken Relay Calculator, was an electromechanical computer built under the direction of Howard Aiken at Harvard University, completed in 1947. It was financed by the United States Navy and used for ballistic calculations at Naval Proving Ground Dahlgren. Computer pioneers Edmund Berkeley and Grace Hopper worked together under Aiken to build and program the Mark II Overview The contract to build the Mark II was signed with Harvard in February 1945, after the successful demonstration of the Mark I in 1944. It was completed and debugged in September 1947, and delivered to the US Navy Proving Ground at Dahlgren, Virginia in March 1948, becoming fully operational by the end of that year. The Mark II was constructed with high-speed electromagnetic relays instead of the electro-mechanical counters used in the Mark I, making it much faster than its predecessor. It weighed and occupied over of floor space. Its addition time was 0.125 seconds (8& ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Howard Aiken
Howard Hathaway Aiken (March 8, 1900 – March 14, 1973) was an American physicist and a list of pioneers in computer science, pioneer in computing. He was the original conceptual designer behind IBM's Harvard Mark I, the United States' first Computer program, programmable computer. Biography Aiken was born on 8 March 1900, in Hoboken, New Jersey, to Daniel Aiken, who came from a wealthy and established Indiana family, and Margaret Emily Mierisch, whose parents were Germans, German immigrants. He grew up in Indianapolis where he graduated from Arsenal Technical High School in 1919. Aiken studied at the University of Wisconsin–Madison where he received his B.S. in electrical engineering in 1923. He later obtained his M.A. and Ph.D. degrees in physics from Harvard University in 1937 and 1939, respectively. During this time, he encountered differential equations that he could only solve numerically. Inspired by Charles Babbage's difference engine, he envisioned an electro-mecha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Floating-point
In computing, floating-point arithmetic (FP) is arithmetic on subsets of real numbers formed by a ''significand'' (a Sign (mathematics), signed sequence of a fixed number of digits in some Radix, base) multiplied by an integer power of that base. Numbers of this form are called floating-point numbers. For example, the number 2469/200 is a floating-point number in base ten with five digits: 2469/200 = 12.345 = \! \underbrace_\text \! \times \! \underbrace_\text\!\!\!\!\!\!\!\overbrace^ However, 7716/625 = 12.3456 is not a floating-point number in base ten with five digits—it needs six digits. The nearest floating-point number with only five digits is 12.346. And 1/3 = 0.3333… is not a floating-point number in base ten with any finite number of digits. In practice, most floating-point systems use Binary number, base two, though base ten (decimal floating point) is also common. Floating-point arithmetic operations, such as addition and division, approximate the correspond ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electro-mechanical Computers
Electromechanics combine processes and procedures drawn from electrical engineering and mechanical engineering. Electromechanics focus on the interaction of electrical and mechanical systems as a whole and how the two systems interact with each other. This process is especially prominent in systems such as those of DC or AC rotating electrical machines which can be designed and operated to generate power from a mechanical process (Electric generator, generator) or used to power a mechanical effect (Electric motor, motor). Electrical engineering in this context also encompasses electronic engineering, electronics engineering. Electromechanical devices are ones which have both electrical and mechanical processes. Strictly speaking, a manually operated switch is an electromechanical component due to the mechanical movement causing an electrical output. Though this is true, the term is usually understood to refer to devices which involve an electrical signal to create mechanical mov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1940s Computers
Year 194 ( CXCIV) was a common year starting on Tuesday of the Julian calendar. At the time, it was known as the Year of the Consulship of Septimius and Septimius (or, less frequently, year 947 ''Ab urbe condita''). The denomination 194 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years. Events By place Roman Empire * Decimus Clodius Septimius Albinus Caesar became a Roman Consul. * Battle of Issus: Septimius Severus marches with his army (12 legions) to Cilicia, and defeats Pescennius Niger, Roman governor of Syria. Pescennius retreats to Antioch, and is executed by Severus' troops. * Septimius Severus besieges Byzantium (194–196); the city walls suffer extensive damage. Asia * Battle of Yan Province: Warlords Cao Cao and Lü Bu fight for control over Yan Province; the battle lasts for over 100 days. * First year of the ''Xingping'' era during the Han Dynasty ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bug (engineering)
In engineering, a bug is a design defect in an engineered system that causes an undesired result. Although used exclusively to describe a technical issue, ''bug'' is a non-technical term; applicable without technical understanding of the system. The term ''bug'' applies exclusively to a system that is (human) designed; not to a natural system; and that the issue is within the influence of human control. For example, humans have faults but not bugs, and a server crash due to natural disaster is not a bug. In addition to or instead of ''defect'', some use: error, flaw or fault. Engineered systems is a broad classification encompassing but not limited to: software, computer hardware, electronics, circuitry and machinery. The undesirable result can be classified and described ''many'' ways including: intermittent, transient, glitch, crash or hang. Since desirability is subjective, what is considered undesirable to one may be considered desirable to another; even a useful feat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harvard Mark IV
The Harvard Mark IV was an electronic stored-program computer built by Harvard University under the supervision of Howard Aiken for the United States Air Force. The computer was completed in 1952. It stayed at Harvard, where the Air Force used it extensively. The Mark IV was all electronic. The Mark IV used a magnetic drum and had 200 registers of ferrite magnetic-core memory (one of the first computers to do so). It separated the storage of data and instructions in what is now sometimes referred to as the Harvard architecture although that term was not coined until the 1970s (in the context of microcontrollers). See also * Harvard Mark I The Harvard Mark I, or IBM Automatic Sequence Controlled Calculator (ASCC), was one of the earliest general-purpose electromechanical computers used in the war effort during the last part of World War II. One of the first programs to run on th ... * Harvard Mark II * Harvard Mark III * List of vacuum-tube computers References Furth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Instruction Set
In computer science, an instruction set architecture (ISA) is an abstract model that generally defines how software controls the CPU in a computer or a family of computers. A device or program that executes instructions described by that ISA, such as a central processing unit (CPU), is called an ''implementation'' of that ISA. In general, an ISA defines the supported Machine code, instructions, data types, Register (computer), registers, the hardware support for managing Computer memory, main memory, fundamental features (such as the memory consistency, addressing modes, virtual memory), and the input/output model of implementations of the ISA. An ISA specifies the behavior of machine code running on implementations of that ISA in a fashion that does not depend on the characteristics of that implementation, providing binary compatibility between implementations. This enables multiple implementations of an ISA that differ in characteristics such as Computer performance, performa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stored-program Computer
A stored-program computer is a computer that stores program instructions in electronically, electromagnetically, or optically accessible memory. This contrasts with systems that stored the program instructions with plugboards or similar mechanisms. The definition is often extended with the requirement that the treatment of programs and data in memory be interchangeable or uniform. Description In principle, stored-program computers have been designed with various architectural characteristics. A computer with a von Neumann architecture stores program data and instruction data in the same memory, while a computer with a Harvard architecture has separate memories for storing program and data. However, the term ''stored-program computer'' is sometimes used as a synonym for the von Neumann architecture. Jack Copeland considers that it is "historically inappropriate, to refer to electronic stored-program digital computers as 'von Neumann machines. Hennessy and Patterson wrote th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bell Labs
Nokia Bell Labs, commonly referred to as ''Bell Labs'', is an American industrial research and development company owned by Finnish technology company Nokia. With headquarters located in Murray Hill, New Jersey, Murray Hill, New Jersey, the company operates several laboratories in the United States and around the world. As a former subsidiary of the American Telephone and Telegraph Company (AT&T), Bell Labs and its researchers have been credited with the development of radio astronomy, the transistor, the laser, the photovoltaic cell, the charge-coupled device (CCD), information theory, the Unix operating system, and the programming languages B (programming language), B, C (programming language), C, C++, S (programming language), S, SNOBOL, AWK, AMPL, and others, throughout the 20th century. Eleven Nobel Prizes and five Turing Awards have been awarded for work completed at Bell Laboratories. Bell Labs had its origin in the complex corporate organization of the Bell System telepho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edmund Berkeley
Edmund Callis Berkeley (March 21, 1909 – March 7, 1988) was an American computer scientist who co-founded the Association for Computing Machinery (ACM) in 1947. His 1949 book ''Giant Brains, or Machines That Think'' popularized cognitive images of early computers. He was also a social activist who worked to achieve conditions that might minimize the threat of nuclear war. Biography Berkeley attended St. Bernard's School and Phillips Exeter Academy. He received a BA in Mathematics and Logic from Harvard in 1930. He pursued a career as an insurance actuary at Prudential Insurance from 1934–1948, except for service in the United States Navy during World War II. Berkeley saw George Stibitz's calculator at Bell Laboratories in 1939, and the Harvard Mark I in 1942. In November 1946 he drafted a specification for "Sequence Controlled Calculators for the Prudential", which led to signing a contract with the Eckert-Mauchly Computer Corporation in 1947 for one of the first UNI ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
First Computer Bug, 1945
First most commonly refers to: * First, the ordinal form of the number 1 First or 1st may also refer to: Acronyms * Faint Images of the Radio Sky at Twenty-Centimeters, an astronomical survey carried out by the Very Large Array * Far Infrared and Sub-millimetre Telescope, of the Herschel Space Observatory * For Inspiration and Recognition of Science and Technology, an international youth organization * Forum of Incident Response and Security Teams, a global forum Arts and entertainment Albums * ''1st'' (album), by Streets, 1983 * ''1ST'' (SixTones album), 2021 * ''First'' (David Gates album), 1973 * ''First'', by Denise Ho, 2001 * ''First'' (O'Bryan album), 2007 * ''First'' (Raymond Lam album), 2011 Extended plays * ''1st'', by The Rasmus, 1995 * ''First'' (Baroness EP), 2004 * ''First'' (Ferlyn G EP), 2015 Songs * "First" (Lindsay Lohan song), 2005 * "First" (Cold War Kids song), 2014 * "First", by Lauren Daigle from the album '' How Can It Be'', 2015 * "First" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
