1.
Infix notation
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Infix notation is the notation commonly used in arithmetical and logical formulae and statements. It is characterized by the placement of operators between operands – infixed operators – such as the sign in 2 +2. Infix notation is more difficult to parse by computers than prefix notation or postfix notation, however many programming languages use it due to its familiarity. It is more used in arithmetic, e. g. 2+2, in the absence of parentheses, certain precedence rules determine the order of operations. Infix notation may also be distinguished from function notation, where the name of a function suggests a particular operation, an example of such a function notation would be S in which the function S denotes addition, S = 1+3 =4. Tree traversal, Infix is also a tree traversal order and it is described in a more detailed manner on this page. A brief analysis of Reverse Polish Notation against Direct Algebraic Logic Infix to postfix convertor
2.
Polish notation
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Its distinguishing feature is that it places operators to the left of their operands. If the arity of the operators is fixed, the result is a syntax lacking parentheses or other brackets that can still be parsed without ambiguity, the Polish logician Jan Łukasiewicz invented this notation in 1924 in order to simplify sentential logic. The term Polish notation is taken to also include Polish postfix notation, or reverse Polish notation. Because of this, Lisp and related programming languages define their entire syntax in terms of prefix notation, I used that notation for the first time in my article Łukasiewicz, p.610, footnote. The reference cited by Łukasiewicz is apparently a lithographed report in Polish, the referring paper by Łukasiewicz Remarks on Nicods Axiom and on Generalizing Deduction was reviewed by H. A. Pogorzelski in the Journal of Symbolic Logic in 1965. He then goes on to cite, as an example, a 1930 paper he wrote with Alfred Tarski on the sentential calculus, while no longer used much in logic, Polish notation has since found a place in computer science. The expression for adding the numbers 1 and 2 is, in prefix notation, in more complex expressions, the operators still precede their operands, but the operands may themselves be nontrivial expressions including operators of their own. As such, the expression can be further simplified to × −567 The processing of the product is deferred until its two operands are available. As with any notation, the innermost expressions are evaluated first, Lisp functions may also have variable arity. The Tcl programming language, much like Lisp also uses Polish notation through the mathop library, the Ambi programming language uses Polish Notation for arithmetic operations and program construction. The postfix reverse Polish notation is used in many stack-based programming languages like PostScript, coffeeScript syntax also allows functions to be called using prefix notation, while still supporting the unary postfix syntax common in other languages. Polish notation, usually in form, is the chosen notation of certain calculators. At a lower level, postfix operators are used by some machines such as the Burroughs Large Systems. Order of operations is defined within the structure of prefix notation, one thing to keep in mind is that when executing an operation, the operation is applied to the first operand by the second operand. This is not an issue with operations that commute, but for non-commutative operations like division or subtraction, for example, the following statement, ÷105 =2 is read as divide 10 by 5. Thus the solution is 2, not 1/2 as would be the result of an incorrect analysis, prefix notation is especially popular with stack-based operations due to its innate ability to easily distinguish order of operations without the need for parentheses. To evaluate order of operations under prefix notation, one not even need to memorize an operational hierarchy. Instead, one directly to the notation to discover which operator to evaluate first
3.
Operation (mathematics)
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In mathematics, an operation is a calculation from zero or more input values to an output value. The number of operands is the arity of the operation, the most commonly studied operations are binary operations of arity 2, such as addition and multiplication, and unary operations of arity 1, such as additive inverse and multiplicative inverse. An operation of arity zero, or 0-ary operation is a constant, the mixed product is an example of an operation of arity 3, or ternary operation. Generally, the arity is supposed to be finite, but infinitary operations are sometimes considered, in this context, the usual operations, of finite arity are also called finitary operations. There are two types of operations, unary and binary. Unary operations involve only one value, such as negation and trigonometric functions, binary operations, on the other hand, take two values, and include addition, subtraction, multiplication, division, and exponentiation. Operations can involve mathematical objects other than numbers, the logical values true and false can be combined using logic operations, such as and, or, and not. Vectors can be added and subtracted, rotations can be combined using the function composition operation, performing the first rotation and then the second. Operations on sets include the binary operations union and intersection and the operation of complementation. Operations on functions include composition and convolution, operations may not be defined for every possible value. For example, in the numbers one cannot divide by zero or take square roots of negative numbers. The values for which an operation is defined form a set called its domain, the set which contains the values produced is called the codomain, but the set of actual values attained by the operation is its range. For example, in the numbers, the squaring operation only produces non-negative numbers. A vector can be multiplied by a scalar to form another vector, and the inner product operation on two vectors produces a scalar. An operation may or may not have certain properties, for example it may be associative, commutative, anticommutative, idempotent, the values combined are called operands, arguments, or inputs, and the value produced is called the value, result, or output. Operations can have fewer or more than two inputs, an operation is like an operator, but the point of view is different. An operation ω is a function of the form ω, V → Y, where V ⊂ X1 × … × Xk. The sets Xk are called the domains of the operation, the set Y is called the codomain of the operation, thus a unary operation has arity one, and a binary operation has arity two
4.
Nationality
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Nationality is the legal relationship between a person and a state. Nationality affords the state jurisdiction over the person and affords the person the protection of the state, what these rights and duties are vary from state to state. By custom and international conventions, it is the right of state to determine who its nationals are. Such determinations are part of nationality law, in some cases, determinations of nationality are also governed by public international law—for example, by treaties on statelessness and the European Convention on Nationality. Nationality differs technically and legally from citizenship, which is a different legal relationship between a person and a country, the noun national can include both citizens and non-citizens. The most common distinguishing feature of citizenship is that citizens have the right to participate in the life of the state. However, in most modern countries all nationals are citizens of the state, in English and some other languages, the word nationality is sometimes used to refer to an ethnic group. This meaning of nationality is not defined by political borders or passport ownership, individuals may also be considered nationals of groups with autonomous status which have ceded some power to a larger government. In international law, nationality is the status or relationship that gives a nation the right to protect a person from other nations, diplomatic and consular protection are dependent upon this relationship between the person and the state. A persons status as being the national of a country is used to resolve the conflict of laws, Nationality is also the status that allows a nation to grant rights to the subject and to impose obligations upon the subject. In most cases, no rights or obligations are automatically attached to this status, although the status is a precondition for any rights. Within the broad limits imposed by few treaties and international law, however, since the Nottebohm case, other states are only required to respect their claim to protect an alleged national if the nationality is based on a true social bond. In the case of dual nationality, states may determine the most effective nationality for a person, there are also limits on removing a persons status as a national. Nationals normally have the right to enter or return to the country belong to. Passports are issued to nationals of a state, rather only to citizens. However, nationals may not have the right of abode in the countries that grant them passports, Nationality is legally a distinct concept from citizenship. Conceptually, citizenship is focused on the political life of the state. In the modern era, the concept of full citizenship encompasses not only political rights
5.
Logic
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Logic, originally meaning the word or what is spoken, is generally held to consist of the systematic study of the form of arguments. A valid argument is one where there is a relation of logical support between the assumptions of the argument and its conclusion. Historically, logic has been studied in philosophy and mathematics, and recently logic has been studied in science, linguistics, psychology. The concept of form is central to logic. The validity of an argument is determined by its logical form, traditional Aristotelian syllogistic logic and modern symbolic logic are examples of formal logic. Informal logic is the study of natural language arguments, the study of fallacies is an important branch of informal logic. Since much informal argument is not strictly speaking deductive, on some conceptions of logic, formal logic is the study of inference with purely formal content. An inference possesses a purely formal content if it can be expressed as an application of a wholly abstract rule, that is. The works of Aristotle contain the earliest known study of logic. Modern formal logic follows and expands on Aristotle, in many definitions of logic, logical inference and inference with purely formal content are the same. This does not render the notion of informal logic vacuous, because no formal logic captures all of the nuances of natural language, Symbolic logic is the study of symbolic abstractions that capture the formal features of logical inference. Symbolic logic is divided into two main branches, propositional logic and predicate logic. Mathematical logic is an extension of logic into other areas, in particular to the study of model theory, proof theory, set theory. Logic is generally considered formal when it analyzes and represents the form of any valid argument type, the form of an argument is displayed by representing its sentences in the formal grammar and symbolism of a logical language to make its content usable in formal inference. Simply put, formalising simply means translating English sentences into the language of logic and this is called showing the logical form of the argument. It is necessary because indicative sentences of ordinary language show a variety of form. Second, certain parts of the sentence must be replaced with schematic letters, thus, for example, the expression all Ps are Qs shows the logical form common to the sentences all men are mortals, all cats are carnivores, all Greeks are philosophers, and so on. The schema can further be condensed into the formula A, where the letter A indicates the judgement all - are -, the importance of form was recognised from ancient times
6.
Arthur Burks
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Decades later, Burks and his wife Alice Burks outlined their case for the subject matter of the ENIAC having been derived from John Vincent Atanasoff. Burks was also for several decades a faculty member at the University of Michigan in Ann Arbor, Burks was born in Duluth, Minnesota. Both Burks and Mauchly sought and obtained teaching positions at the Moore School the following fall, when Mauchly and Eckerts proposed concept for an electronic digital computer was funded by the U. S. Armys Ballistics Research Laboratory in June 1943, Burks was added to the design team. Among his principal contributions to the project was the design of the multiplier unit. In April 1945, with John Grist Brainerd, Burks was charged with writing the reports on the ENIAC for publication. Also during 1945 Burks assisted with the logical design of the EDVAC in meetings attended by Mauchly, Eckert, John von Neumann. Burks also took a position as a philosophy instructor at Swarthmore College during 1945-1946. On March 8,1946 Burks accepted an offer by von Neumann to join the project at the Institute for Advanced Study in Princeton, New Jersey. During his time at the IAS, Burks worked to expand von Neumanns theory of automata and he declined a position heading up a different universitys computing center, citing his primary interest as the purely theoretical aspects of computing machines. He was awarded the Louis E. Levi Medal in 1956, Burks doctoral students include John Holland, who in 1959 was the first student to receive a Ph. D. in computer science from Michigan, and possibly the first in the world. Burks served as president of the Charles S. Peirce Society in 1954-1955 and he edited the final two volumes, published 1958, of the Collected Papers of Charles Sanders Peirce and, over the years, wrote published articles on Peirce. In the 1960s he was presented with the opportunity to acquire four units of the original ENIAC and he ran the units through a car wash before restoring them and donating them to the University of Michigan. They are currently on display in the entryway of the Computer Science Building, in 1964 Burks was approached by attorney Sy Yuter and asked to join T. Kite Sharpless and Robert F. In the 1970s Burks began meeting with Bob Axelrod, Michael Cohen, the BACH group continues to meet irregularly as part of the University of Michigans Center for the Study of Complex Systems. In the 1970s and 1980s Burks, working with his wife Alice, authored a number of articles on the ENIAC, in 1990, Burks donated a portion of his papers to the universitys Bentley Historical Library, where they are accessible to researchers. Burks died May 14,2008 in an Ann Arbor, Michigan nursing home from Alzheimers disease, Burks, Arthur W. and Wright, Jesse Bowdle, Theory of Logical Nets. Amazon says, published by Burroughs Adding Machine Co, google Books says, published by University of Michigan Engineering Research Institute,52 pages. Burks, Arthur W. and Copi, Irving M, the logic of fixed and growing automata, Engineering Research Institute, University of Michigan,34 pages
7.
Friedrich L. Bauer
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Friedrich Ludwig Fritz Bauer was a German computer scientist and professor at the Technical University of Munich. Bauer earned his Abitur in 1942 and served in the Wehrmacht during World War II, from 1946 to 1950, he studied mathematics and theoretical physics at Ludwig-Maximilians-Universität in Munich. Bauer received his doctorate under the supervision of Fritz Bopp for his thesis Gruppentheoretische Untersuchungen zur Theorie der Spinwellengleichungen in 1952 and he completed his habilitation Über quadratisch konvergente Iterationsverfahren zur Lösung von algebraischen Gleichungen und Eigenwertproblemen in 1954 at the Technical University of Munich. After teaching as privatdozent at Ludwig-Maximilians-Universität from 1954 to 1958, he became professor for applied mathematics at the University of Mainz. Since 1963, he worked as a professor of mathematics and computer science at Technical University of Munich, bauers early work involved the construction of computing machinery. In this context, he was the first to propose the widely used method of expression evaluation. In 1968, Bauer coined the term Software Engineering which has been in use since. Bauer was a figure in establishing computer science as an independent subject in German universities. He also wrote a book on cryptology, Decrypted secrets. He was the advisor of 39 students, including Manfred Broy, David Gries, Manfred Paul, Gerhard Seegmüller, Josef Stoer, Peter Wynn. Friedrich Bauer was married to Hildegard Bauer-Vogg and he was the father of three sons and two daughters. Bauer was a colleague of the German Representative the NATO Science Committee, in 1967, NATO had been discussing The Software Crisis and Bauer had suggested the term Software Engineering as a way to conceive of both the problem and the solution. ACM3, 76-83, an influential paper on compilers 1964 Introduction to Algol. Bauer, Charles Babbage Institute, University of Minnesota, Bauer discusses his education and early research, including the European side of the development of ALGOL, as well as his later work in numerical analysis and programming languages. Photograph of F. L. Bauer Bauer about Rutishauser at a symposium at the ETH Zürich in 2002 Friedrich L. Bauer at the Mathematics Genealogy Project Author profile in the database zbMATH
8.
Edsger W. Dijkstra
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Edsger Wybe Dijkstra was a Dutch computer scientist and an early pioneer in many research areas of computing science. A theoretical physicist by training, he worked as a programmer at the Mathematisch Centrum from 1952 to 1962 and he was a professor of mathematics at the Eindhoven University of Technology and a research fellow at the Burroughs Corporation. He held the Schlumberger Centennial Chair in Computer Sciences at the University of Texas at Austin from 1984 until 1999, one of the most influential members of computing sciences founding generation, Dijkstra helped shape the new discipline from both an engineering and a theoretical perspective. Many of his papers are the source of new research areas, several concepts and problems that are now standard in computer science were first identified by Dijkstra or bear names coined by him. Dijkstra coined the phrase structured programming and during the 1970s this became the new programming orthodoxy, the academic study of concurrent computing started in the 1960s, with Dijkstra credited with being the first paper in this field, identifying and solving the mutual exclusion problem. He was also one of the pioneers of the research on principles of distributed computing. Shortly before his death in 2002, he received the ACM PODC Influential-Paper Award in distributed computing for his work on self-stabilization of program computation and this annual award was renamed the Dijkstra Prize the following year, in his honor. Edsger W. Dijkstra was born in Rotterdam and his father was a chemist who was president of the Dutch Chemical Society, he taught chemistry at a secondary school and was later its superintendent. His mother was a mathematician, but never had a formal job, Dijkstra had considered a career in law and had hoped to represent the Netherlands in the United Nations. However, after graduating school in 1948, at his parents suggestion he studied mathematics and physics. In the early 1950s, electronic computers were a novelty, Dijkstra stumbled on his career quite by accident, and through his supervisor, Professor A. For some time Dijkstra remained committed to physics, working on it in Leiden three days out of each week, with increasing exposure to computing, however, his focus began to shift. But was that a respectable profession, for after all, what was programming. Where was the body of knowledge that could support it as an intellectually respectable discipline. Full of misgivings I knocked on van Wijngaardens office door, asking him whether I could speak to him for a moment and this was a turning point in my life and I completed my study of physics formally as quickly as I could. Debets in 1957, he was required as a part of the rites to state his profession. He stated that he was a programmer, which was unacceptable to the authorities and his thesis supervisor was van Wijngaarden. From 1952 until 1962 Dijkstra worked at the Mathematisch Centrum in Amsterdam, where he worked closely with Bram Jan Loopstra and Carel S. Scholten, who had been hired to build a computer
9.
Computer memory
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In computing, memory refers to the computer hardware devices involved to store information for immediate use in a computer, it is synonymous with the term primary storage. Computer memory operates at a speed, for example random-access memory, as a distinction from storage that provides slow-to-access program and data storage. If needed, contents of the memory can be transferred to secondary storage. An archaic synonym for memory is store, there are two main kinds of semiconductor memory, volatile and non-volatile. Examples of non-volatile memory are flash memory and ROM, PROM, EPROM and EEPROM memory, most semiconductor memory is organized into memory cells or bistable flip-flops, each storing one bit. Flash memory organization includes both one bit per cell and multiple bits per cell. The memory cells are grouped into words of fixed word length, each word can be accessed by a binary address of N bit, making it possible to store 2 raised by N words in the memory. This implies that processor registers normally are not considered as memory, since they only store one word, typical secondary storage devices are hard disk drives and solid-state drives. In the early 1940s, memory technology oftenly permit a capacity of a few bytes, the next significant advance in computer memory came with acoustic delay line memory, developed by J. Presper Eckert in the early 1940s. Delay line memory would be limited to a capacity of up to a few hundred thousand bits to remain efficient, two alternatives to the delay line, the Williams tube and Selectron tube, originated in 1946, both using electron beams in glass tubes as means of storage. Using cathode ray tubes, Fred Williams would invent the Williams tube, the Williams tube would prove more capacious than the Selectron tube and less expensive. The Williams tube would prove to be frustratingly sensitive to environmental disturbances. Efforts began in the late 1940s to find non-volatile memory, jay Forrester, Jan A. Rajchman and An Wang developed magnetic core memory, which allowed for recall of memory after power loss. Magnetic core memory would become the dominant form of memory until the development of transistor-based memory in the late 1960s, developments in technology and economies of scale have made possible so-called Very Large Memory computers. The term memory when used with reference to computers generally refers to Random Access Memory or RAM, volatile memory is computer memory that requires power to maintain the stored information. Most modern semiconductor volatile memory is either static RAM or dynamic RAM, SRAM retains its contents as long as the power is connected and is easy for interfacing, but uses six transistors per bit. SRAM is not worthwhile for desktop system memory, where DRAM dominates, SRAM is commonplace in small embedded systems, which might only need tens of kilobytes or less. Forthcoming volatile memory technologies that aim at replacing or competing with SRAM and DRAM include Z-RAM and A-RAM, non-volatile memory is computer memory that can retain the stored information even when not powered
10.
Stack (abstract data type)
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The order in which elements come off a stack gives rise to its alternative name, LIFO. Additionally, an operation may give access to the top without modifying the stack. Considered as a data structure, or more abstractly a sequential collection. This makes it possible to implement a stack as a linked list. A stack may be implemented to have a bounded capacity, if the stack is full and does not contain enough space to accept an entity to be pushed, the stack is then considered to be in an overflow state. The pop operation removes an item from the top of the stack, Stacks entered the computer science literature in 1946, in the computer design of Alan M. Turing as a means of calling and returning from subroutines. Subroutines had already implemented in Konrad Zuses Z4 in 1945. Klaus Samelson and Friedrich L. Bauer of Technical University Munich proposed the idea in 1955, the same concept was developed, independently, by the Australian Charles Leonard Hamblin in the first half of 1957. Stacks are often described by analogy to a stack of plates in a cafeteria. Clean plates are placed on top of the stack, pushing down any already there, when a plate is removed from the stack, the one below it pops up to become the new top. In many implementations, a stack has more operations than push, an example is top of stack, or peek, which observes the top-most element without removing it from the stack. Since this can be done with a pop and a push with the same data, an underflow condition can occur in the stack top operation if the stack is empty, the same as pop. Also, implementations often have a function which just returns whether the stack is empty, a stack can be easily implemented either through an array or a linked list. The following will demonstrate both implementations, using pseudocode, an array can be used to implement a stack, as follows. The first element is the bottom, resulting in array being the first element pushed onto the stack, some languages, notably those in the Forth family, are designed around language-defined stacks that are directly visible to and manipulated by the programmer. Javas library contains a Stack class that is a specialization of Vector, following is an example program in Java language, using that class. A common use of stacks at the level is as a means of allocating and accessing memory. A typical stack is an area of memory with a fixed origin
11.
Algorithm
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In mathematics and computer science, an algorithm is a self-contained sequence of actions to be performed. Algorithms can perform calculation, data processing and automated reasoning tasks, an algorithm is an effective method that can be expressed within a finite amount of space and time and in a well-defined formal language for calculating a function. The transition from one state to the next is not necessarily deterministic, some algorithms, known as randomized algorithms, giving a formal definition of algorithms, corresponding to the intuitive notion, remains a challenging problem. In English, it was first used in about 1230 and then by Chaucer in 1391, English adopted the French term, but it wasnt until the late 19th century that algorithm took on the meaning that it has in modern English. Another early use of the word is from 1240, in a manual titled Carmen de Algorismo composed by Alexandre de Villedieu and it begins thus, Haec algorismus ars praesens dicitur, in qua / Talibus Indorum fruimur bis quinque figuris. Which translates as, Algorism is the art by which at present we use those Indian figures, the poem is a few hundred lines long and summarizes the art of calculating with the new style of Indian dice, or Talibus Indorum, or Hindu numerals. An informal definition could be a set of rules that precisely defines a sequence of operations, which would include all computer programs, including programs that do not perform numeric calculations. Generally, a program is only an algorithm if it stops eventually, but humans can do something equally useful, in the case of certain enumerably infinite sets, They can give explicit instructions for determining the nth member of the set, for arbitrary finite n. An enumerably infinite set is one whose elements can be put into one-to-one correspondence with the integers, the concept of algorithm is also used to define the notion of decidability. That notion is central for explaining how formal systems come into being starting from a set of axioms. In logic, the time that an algorithm requires to complete cannot be measured, from such uncertainties, that characterize ongoing work, stems the unavailability of a definition of algorithm that suits both concrete and abstract usage of the term. Algorithms are essential to the way computers process data, thus, an algorithm can be considered to be any sequence of operations that can be simulated by a Turing-complete system. Although this may seem extreme, the arguments, in its favor are hard to refute. Gurevich. Turings informal argument in favor of his thesis justifies a stronger thesis, according to Savage, an algorithm is a computational process defined by a Turing machine. Typically, when an algorithm is associated with processing information, data can be read from a source, written to an output device. Stored data are regarded as part of the state of the entity performing the algorithm. In practice, the state is stored in one or more data structures, for some such computational process, the algorithm must be rigorously defined, specified in the way it applies in all possible circumstances that could arise. That is, any conditional steps must be dealt with, case-by-case
12.
Australia
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Australia, officially the Commonwealth of Australia, is a country comprising the mainland of the Australian continent, the island of Tasmania and numerous smaller islands. It is the worlds sixth-largest country by total area, the neighbouring countries are Papua New Guinea, Indonesia and East Timor to the north, the Solomon Islands and Vanuatu to the north-east, and New Zealand to the south-east. Australias capital is Canberra, and its largest urban area is Sydney, for about 50,000 years before the first British settlement in the late 18th century, Australia was inhabited by indigenous Australians, who spoke languages classifiable into roughly 250 groups. The population grew steadily in subsequent decades, and by the 1850s most of the continent had been explored, on 1 January 1901, the six colonies federated, forming the Commonwealth of Australia. Australia has since maintained a liberal democratic political system that functions as a federal parliamentary constitutional monarchy comprising six states. The population of 24 million is highly urbanised and heavily concentrated on the eastern seaboard, Australia has the worlds 13th-largest economy and ninth-highest per capita income. With the second-highest human development index globally, the country highly in quality of life, health, education, economic freedom. The name Australia is derived from the Latin Terra Australis a name used for putative lands in the southern hemisphere since ancient times, the Dutch adjectival form Australische was used in a Dutch book in Batavia in 1638, to refer to the newly discovered lands to the south. On 12 December 1817, Macquarie recommended to the Colonial Office that it be formally adopted, in 1824, the Admiralty agreed that the continent should be known officially as Australia. The first official published use of the term Australia came with the 1830 publication of The Australia Directory and these first inhabitants may have been ancestors of modern Indigenous Australians. The Torres Strait Islanders, ethnically Melanesian, were originally horticulturists, the northern coasts and waters of Australia were visited sporadically by fishermen from Maritime Southeast Asia. The first recorded European sighting of the Australian mainland, and the first recorded European landfall on the Australian continent, are attributed to the Dutch. The first ship and crew to chart the Australian coast and meet with Aboriginal people was the Duyfken captained by Dutch navigator, Willem Janszoon. He sighted the coast of Cape York Peninsula in early 1606, the Dutch charted the whole of the western and northern coastlines and named the island continent New Holland during the 17th century, but made no attempt at settlement. William Dampier, an English explorer and privateer, landed on the north-west coast of New Holland in 1688, in 1770, James Cook sailed along and mapped the east coast, which he named New South Wales and claimed for Great Britain. The first settlement led to the foundation of Sydney, and the exploration, a British settlement was established in Van Diemens Land, now known as Tasmania, in 1803, and it became a separate colony in 1825. The United Kingdom formally claimed the part of Western Australia in 1828. Separate colonies were carved from parts of New South Wales, South Australia in 1836, Victoria in 1851, the Northern Territory was founded in 1911 when it was excised from South Australia
13.
Philosopher
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A philosopher is someone who practices philosophy, which involves rational inquiry into areas that are outside of either theology or science. The term philosopher comes from the Ancient Greek φιλόσοφος meaning lover of wisdom, the coining of the term has been attributed to the Greek thinker Pythagoras. Typically, these brands of philosophy are Hellenistic ones and those who most arduously commit themselves to this lifestyle may be considered philosophers. The separation of philosophy and science from theology began in Greece during the 6th century BC, thales, an astronomer and mathematician, was considered by Aristotle to be the first philosopher of the Greek tradition. While Pythagoras coined the word, the first known elaboration on the topic was conducted by Plato, in his Symposium, he concludes that Love is that which lacks the object it seeks. Therefore, the philosopher is one who seeks wisdom, if he attains wisdom, therefore, the philosopher in antiquity was one who lives in the constant pursuit of wisdom, and living in accordance to that wisdom. Disagreements arose as to what living philosophically entailed and these disagreements gave rise to different Hellenistic schools of philosophy. In consequence, the ancient philosopher thought in a tradition, as the ancient world became schism by philosophical debate, the competition lay in living in manner that would transform his whole way of living in the world. Philosophy is a discipline which can easily carry away the individual in analyzing the universe. The second is the change through the Medieval era. With the rise of Christianity, the way of life was adopted by its theology. Thus, philosophy was divided between a way of life and the conceptual, logical, physical and metaphysical materials to justify that way of life, philosophy was then the servant to theology. The third is the sociological need with the development of the university, the modern university requires professionals to teach. Maintaining itself requires teaching future professionals to replace the current faculty, therefore, the discipline degrades into a technical language reserved for specialists, completely eschewing its original conception as a way of life. In the fourth century, the word began to designate a man or woman who led a monastic life. Gregory of Nyssa, for example, describes how his sister Macrina persuaded their mother to forsake the distractions of life for a life of philosophy. Later during the Middle Ages, persons who engaged with alchemy was called a philosopher - thus, many philosophers still emerged from the Classical tradition, as saw their philosophy as a way of life. Among the most notable are René Descartes, Baruch Spinoza, Nicolas Malebranche, with the rise of the university, the modern conception of philosophy became more prominent
14.
Hewlett-Packard
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The Hewlett-Packard Company or shortened to Hewlett-Packard was an American multinational information technology company headquartered in Palo Alto, California. The company was founded in a garage in Palo Alto by William Bill Redington Hewlett and David Dave Packard. HP was the worlds leading PC manufacturer from 2007 to Q22013 and it specialized in developing and manufacturing computing, data storage, and networking hardware, designing software and delivering services. HP also had services and consulting business around its products and partner products.4 billion in 2008, in November 2009, HP announced the acquisition of 3Com, with the deal closing on April 12,2010. On April 28,2010, HP announced the buyout of Palm, on September 2,2010, HP won its bidding war for 3PAR with a $33 a share offer, which Dell declined to match. On October 6,2014, Hewlett-Packard announced plans to split the PC and printers business from its enterprise products, the split closed on November 1,2015, and resulted in two publicly traded companies, HP Inc. and Hewlett Packard Enterprise. William Redington Hewlett and David Packard graduated with degrees in engineering from Stanford University in 1935. The company originated in a garage in nearby Palo Alto during a fellowship they had with a past professor, Terman was considered a mentor to them in forming Hewlett-Packard. In 1939, Packard and Hewlett established Hewlett-Packard in Packards garage with a capital investment of US$538. Hewlett and Packard tossed a coin to decide whether the company they founded would be called Hewlett-Packard or Packard-Hewlett, HP incorporated on August 18,1947, and went public on November 6,1957. Of the many projects they worked on, their very first financially successful product was an audio oscillator. This allowed them to sell the Model 200A for $54.40 when competitors were selling less stable oscillators for over $200, the Model 200 series of generators continued until at least 1972 as the 200AB, still tube-based but improved in design through the years. They worked on technology and artillery shell fuses during World War II. Hewlett-Packards HP Associates division, established around 1960, developed semiconductor devices primarily for internal use, instruments and calculators were some of the products using these devices. HP partnered in the 1960s with Sony and the Yokogawa Electric companies in Japan to develop several high-quality products, the products were not a huge success, as there were high costs in building HP-looking products in Japan. HP and Yokogawa formed a joint venture in 1963 to market HP products in Japan, HP bought Yokogawa Electrics share of Hewlett-Packard Japan in 1999. HP spun off a company, Dynac, to specialize in digital equipment. The name was picked so that the HP logo hp could be turned upside down to be a reverse image of the logo dy of the new company
15.
Computer science
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Computer science is the study of the theory, experimentation, and engineering that form the basis for the design and use of computers. An alternate, more succinct definition of science is the study of automating algorithmic processes that scale. A computer scientist specializes in the theory of computation and the design of computational systems and its fields can be divided into a variety of theoretical and practical disciplines. Some fields, such as computational complexity theory, are highly abstract, other fields still focus on challenges in implementing computation. Human–computer interaction considers the challenges in making computers and computations useful, usable, the earliest foundations of what would become computer science predate the invention of the modern digital computer. Machines for calculating fixed numerical tasks such as the abacus have existed since antiquity, further, algorithms for performing computations have existed since antiquity, even before the development of sophisticated computing equipment. Wilhelm Schickard designed and constructed the first working mechanical calculator in 1623, in 1673, Gottfried Leibniz demonstrated a digital mechanical calculator, called the Stepped Reckoner. He may be considered the first computer scientist and information theorist, for, among other reasons and he started developing this machine in 1834, and in less than two years, he had sketched out many of the salient features of the modern computer. A crucial step was the adoption of a card system derived from the Jacquard loom making it infinitely programmable. Around 1885, Herman Hollerith invented the tabulator, which used punched cards to process statistical information, when the machine was finished, some hailed it as Babbages dream come true. During the 1940s, as new and more powerful computing machines were developed, as it became clear that computers could be used for more than just mathematical calculations, the field of computer science broadened to study computation in general. Computer science began to be established as an academic discipline in the 1950s. The worlds first computer science program, the Cambridge Diploma in Computer Science. The first computer science program in the United States was formed at Purdue University in 1962. Since practical computers became available, many applications of computing have become distinct areas of study in their own rights and it is the now well-known IBM brand that formed part of the computer science revolution during this time. IBM released the IBM704 and later the IBM709 computers, still, working with the IBM was frustrating if you had misplaced as much as one letter in one instruction, the program would crash, and you would have to start the whole process over again. During the late 1950s, the science discipline was very much in its developmental stages. Time has seen significant improvements in the usability and effectiveness of computing technology, modern society has seen a significant shift in the users of computer technology, from usage only by experts and professionals, to a near-ubiquitous user base
16.
Stack-oriented programming language
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A stack-oriented programming language is one that relies on a stack machine model for passing parameters. Several programming languages fit this description, notably Forth, RPL, PostScript, BibTeX style design language, stack-oriented languages operate on one or more stacks, each of which may serve a different purpose. Thus, programming constructs in other programming languages may need to be modified for use in a stack-oriented system, further, some stack-oriented languages operate in postfix or Reverse Polish notation, that is, any arguments or parameters for a command are stated before that command. For example, postfix notation would be written 2,3, multiply instead of multiply,2,3, assume a postfix stack-based language, like PostScript. To understand how stack-orientation works, in calculating an expression such as 23 mul, imagine standing at the end of a conveyor belt, onto which have been placed plates marked 2,3, and mul. One can take the plate at the end of the conveyor, the only way plates can be stored is in a stack, and plates can only be added or removed from atop the stack, not from the middle or bottom. One also has a supply of blank plates, and can discard plates, take plate 2 and put it on the stack, then take plate 3 and put it on the stack. This is an instruction to perform, then, take the top two plates off the stack, multiply their labels, and write the result on a new plate. Discard the two old plates and the plate mul, and put the new plate on the stack, with no more plates remaining on the conveyor, the result of the calculation is shown on the plate atop the stack. This is a simple calculation. What if a complex calculation is needed, such as ×11 +1. If it is first written in form, that is,23 add 11 mul 1 add. The steps of the calculation are shown in the table below, each column shows an input element, and the contents of the stack after processing that input. After processing all the input, the stack contains 56, which is the answer, any expression that can be written conventionally, or in another programming language, can be written in postfix form and thus be amenable to being interpreted by a stack-oriented language. Since the stack is the key means to manipulate data in a stack-oriented language and these become key in studying procedures. As an aid to understanding the effect of statement, a comment is used showing the top of the stack before. The top of the stack is rightmost if there are multiple items and this notation is commonly used in the Forth language, where comments are enclosed in parentheses. For example, the basic Forth stack operators are described, dup drop swap over rot And the fib function below is described, both comments may also be referenced as assertions, thought not necessarily in context of Stack-based languages
17.
Forth (programming language)
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Forth is an imperative stack-based computer programming language and environment originally designed by Charles Chuck Moore. Language features include structured programming, reflection, concatenative programming and extensibility, although not an acronym, the languages name is sometimes spelled with all capital letters as FORTH, following the customary usage during its earlier years. A procedural programming language without type checking, Forth features both interactive execution of commands and the ability to compile sequences of commands for later execution, some Forth implementations compile threaded code, but many implementations today generate optimized machine code like other language compilers. Forth is used in the Open Firmware boot loader, in applications, such as the Philae spacecraft. The bestselling 1986 DOS game Starflight, from Electronic Arts, was written with a custom Forth, the free software Gforth implementation is actively maintained, as are several commercially supported systems. A Forth environment combines the compiler with a shell, where the user defines. Words can be tested, redefined, and debugged as the source is entered without recompiling or restarting the whole program, all syntactic elements, including variables and basic operators, are defined as words. Forth environments vary in how the program is stored. Most programming environments with recursive subroutines use a stack for control flow and this structure typically also stores local variables, including subroutine parameters. Forth often does not have local variables, however, nor is it call-by-value, instead, intermediate values are kept in another stack, different from the one it uses for return addresses, loop counters, etc. Words operate directly on the topmost values in the first of these two stacks and it may therefore be called the parameter or data stack, but most often simply the stack. The second, function-call stack is then called the linkage or return stack, most words are specified in terms of their effect on the stack. Typically, parameters are placed on the top of the stack before the word executes, after execution, the parameters have been erased and replaced with any return values. For arithmetic operators, this follows the rule of reverse Polish notation, see below for examples illustrating stack usage. Forth is a simple yet extensible language, its modularity and extensibility permit the writing of programs such as CAD systems. Forth has a niche both in astronomical and space applications, Forth is still used today in many embedded systems because of its portability, efficient memory use, short development time, and fast execution speed. It has been implemented efficiently on modern RISC processors, and processors that use Forth as machine language have been produced. Other uses of Forth include the Open Firmware boot ROMs used by Apple, IBM, Sun, and OLPC XO-1, Forth evolved from Charles H. Moores personal programming system, which had been in continuous development since 1968
18.
PostScript
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PostScript is a page description language in the electronic publishing and desktop publishing business. It is a typed, concatenative programming language and was created at Adobe Systems by John Warnock, Charles Geschke, Doug Brotz, Ed Taft. The concepts of the PostScript language were seeded in 1976 when John Warnock was working at Evans & Sutherland, at that time John Warnock was developing an interpreter for a large three-dimensional graphics database of New York harbor. Warnock conceived the Design System language to process the graphics, concurrently, researchers at Xerox PARC had developed the first laser printer and had recognized the need for a standard means of defining page images. In 1975-76 Bob Sproull and William Newman developed the Press format, but Press, a data format rather than a language, lacked flexibility, and PARC mounted the Interpress effort to create a successor. In 1978 Evans & Sutherland asked Warnock to move from the San Francisco Bay Area to their headquarters in Utah. He then joined Xerox PARC to work with Martin Newell and they rewrote Design System to create J & M which was used for VLSI design and the investigation of type and graphics printing. This work later evolved and expanded into the Interpress language, Warnock left with Chuck Geschke and founded Adobe Systems in December 1982. They, together with Doug Brotz, Ed Taft and Bill Paxton created a language, similar to Interpress, called PostScript. At about this time they were visited by Steve Jobs, who urged them to adapt PostScript to be used as the language for driving laser printers. In March 1985, the Apple LaserWriter was the first printer to ship with PostScript, the combination of technical merits and widespread availability made PostScript a language of choice for graphical output for printing applications. For a time an interpreter for the PostScript language was a component of laser printers. However, the cost of implementation was high, computers output raw PS code that would be interpreted by the printer into an image at the printers natural resolution. This required high performance microprocessors and ample memory, the LaserWriter used a 12 MHz Motorola 68000, making it faster than any of the Macintosh computers to which it attached. When the laser printer engines themselves cost over a thousand dollars the added cost of PS was marginal, the first version of the PostScript language was released to the market in 1984. The term Level 1 was added when Level 2 was introduced, PostScript 3 came at the end of 1997, and along with many new dictionary-based versions of older operators, introduced better color handling, and new filters. Prior to the introduction of PostScript, printers were designed to print character output given the text—typically in ASCII—as input and this changed to some degree with the increasing popularity of dot matrix printers. The characters on these systems were drawn as a series of dots, dot matrix printers also introduced the ability to print raster graphics
19.
Factorial
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In mathematics, the factorial of a non-negative integer n, denoted by n. is the product of all positive integers less than or equal to n. =5 ×4 ×3 ×2 ×1 =120, the value of 0. is 1, according to the convention for an empty product. The factorial operation is encountered in areas of mathematics, notably in combinatorics, algebra. Its most basic occurrence is the fact there are n. ways to arrange n distinct objects into a sequence. This fact was known at least as early as the 12th century, fabian Stedman, in 1677, described factorials as applied to change ringing. After describing a recursive approach, Stedman gives a statement of a factorial, Now the nature of these methods is such, the factorial function is formally defined by the product n. = ∏ k =1 n k, or by the relation n. = {1 if n =0. The factorial function can also be defined by using the rule as n. All of the above definitions incorporate the instance 0, =1, in the first case by the convention that the product of no numbers at all is 1. This is convenient because, There is exactly one permutation of zero objects, = n. ×, valid for n >0, extends to n =0. It allows for the expression of many formulae, such as the function, as a power series. It makes many identities in combinatorics valid for all applicable sizes, the number of ways to choose 0 elements from the empty set is =0. More generally, the number of ways to choose n elements among a set of n is = n. n, the factorial function can also be defined for non-integer values using more advanced mathematics, detailed in the section below. This more generalized definition is used by advanced calculators and mathematical software such as Maple or Mathematica, although the factorial function has its roots in combinatorics, formulas involving factorials occur in many areas of mathematics. There are n. different ways of arranging n distinct objects into a sequence, often factorials appear in the denominator of a formula to account for the fact that ordering is to be ignored. A classical example is counting k-combinations from a set with n elements, one can obtain such a combination by choosing a k-permutation, successively selecting and removing an element of the set, k times, for a total of n k _ = n ⋯ possibilities. This however produces the k-combinations in an order that one wishes to ignore, since each k-combination is obtained in k. different ways. This number is known as the coefficient, because it is also the coefficient of Xk in n
20.
Shunting-yard algorithm
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In computer science, the shunting-yard algorithm is a method for parsing mathematical expressions specified in infix notation. It can be used to either a postfix notation string, also known as Reverse Polish notation. The algorithm was invented by Edsger Dijkstra and named the shunting yard algorithm because its operation resembles that of a shunting yard. Dijkstra first described the Shunting Yard Algorithm in the Mathematisch Centrum report MR 34/61, like the evaluation of RPN, the shunting yard algorithm is stack-based. Infix expressions are the form of mathematical notation most people are used to, for the conversion there are two text variables, the input and the output. There is also a stack that holds operators not yet added to the output queue, to convert, the program reads each symbol in order and does something based on that symbol. The result for the examples would be 34 + or 3421 - * +. The shunting-yard algorithm has been generalized into operator-precedence parsing. Input, 3+4 Push 3 to the output queue Push + onto the operator stack Push 4 to the output queue After reading the expression, pop the operators off the stack, in this case there is only one, +. Output 34 + This already shows a couple of rules, at the end of reading the expression, pop all operators off the stack and onto the output. While there are tokens to be read, Read a token, If the token is a number, then push it to the output queue. If the token is a token, then push it onto the stack. If the token is a function argument separator, Until the token at the top of the stack is a left parenthesis, If no left parentheses are encountered, either the separator was misplaced or parentheses were mismatched. If the token is a parenthesis, Until the token at the top of the stack is a left parenthesis. Pop the left parenthesis from the stack, but not onto the output queue, If the token at the top of the stack is a function token, pop it onto the output queue. If the stack runs out without finding a left parenthesis, then there are mismatched parentheses. When there are no more tokens to read, While there are still operator tokens in the stack, If the operator token on the top of the stack is a parenthesis, pop the operator onto the output queue. The shunting yard algorithm can also be applied to produce prefix notation, to do this one would simply start from the end of a string of tokens to be parsed and work backwards, reverse the output queue, and flip the left and right parenthesis behavior
21.
Classification yard
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A classification yard or marshalling yard is a railway yard found at some freight train stations, used to separate railway cars on to one of several tracks. First the cars are taken to a track, sometimes called a lead or a drill, from there the cars are sent through a series of switches called a ladder onto the classification tracks. Larger yards tend to put the lead on an artificially built hill called a hump to use the force of gravity to propel the cars through the ladder, freight trains that consist of isolated cars must be made into trains and divided according to their destinations. Thus the cars must be shunted several times along their route in contrast to a unit train and this shunting is done partly at the starting and final destinations and partly in classification yards. Flat yards are constructed on ground, or on a gentle slope. Freight cars are pushed by a locomotive and coast to their required location, hump yards are the largest and most effective classification yards, with the largest shunting capacity, often several thousand cars a day. The heart of these yards is the lead track on a small hill over which an engine pushes the cars. As concerns speed regulation, there are two types of hump yards—without or with mechanisation by retarders, in the old non-retarder yards braking was usually done in Europe by railroaders who laid skates onto the tracks. The skate or chock was manually placed on one or both of the rails so that the treadles or rims of the wheel or wheels caused frictional retardation, in the United States this braking was done by riders on the cars. In the modern retarder yards this work is done by mechanized rail brakes called retarders and they are operated either pneumatically or hydraulically. Pneumatic systems are prevalent in the United States, France, Belgium, Russia and China, while hydraulic systems are used in Germany, Italy and the Netherlands. In the United States, many classification bowls have more than 40 tracks—up to 72—which are often divided into six to ten tracks in each balloon loop. Bailey Yard in North Platte, Nebraska, United States, the worlds largest classification yard, is a hump yard, notably, in Europe, Russia and China, all major classification yards are hump yards. Europes largest hump yard is that of Maschen near Hamburg, Germany, the second largest is in the port of Antwerp, Belgium. According to the PRRT&HS PRR Chronology, the first hump yard in the United States was opened May 11,1903 as part of the Altoona Yards at Bells Mills. Other sources report the PRR yard at Youngwood, PA which opened in the 1880s to serve the Connellsville coke fields as the first U. S. hump yard. Gravity yards are operated similarly to hump yards but, in contrast to the latter, thus, only few gravity yards were ever built, sometimes requiring massive earthwork. Most gravity yards were built in Germany and Great Britain, a few also in some other European countries, in the USA, there were only very few old gravity yards, one of the few gravity yards in operation today is CSXs Readville Yard south of Boston, Massachusetts
22.
Abstract syntax tree
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In computer science, an abstract syntax tree, or just syntax tree, is a tree representation of the abstract syntactic structure of source code written in a programming language. Each node of the tree denotes a construct occurring in the source code, the syntax is abstract in not representing every detail appearing in the real syntax. For instance, grouping parentheses are implicit in the structure. This distinguishes abstract syntax trees from concrete syntax trees, traditionally designated parse trees, once built, additional information is added to the AST by means of subsequent processing, e. g. contextual analysis. Abstract syntax trees are used in program analysis and program transformation systems. Abstract syntax trees are data structures used in compilers, due to their property of representing the structure of program code. An AST is usually the result of the analysis phase of a compiler. It often serves as a representation of the program through several stages that the compiler requires. Being the product of the analysis phase of a compiler. Compared to the code, an AST does not include certain elements, such as inessential punctuation. A more important difference is that the AST can be edited and enhanced with information such as properties, such editing and annotation is impossible with the source code of a program, since it would imply changing it. This information may be used to notify the user of the location of an error in the code, aSTs are needed because of the inherent nature of programming languages and their documentation. Languages are often ambiguous by nature, in order to avoid this ambiguity, programming languages are often specified as a context-free grammar. However, there are aspects of programming languages that a CFG cant express. These are details that require a context to determine their validity, for example, if a language allows new types to be declared, a CFG cannot predict the names of such types nor the way in which they should be used. Even if a language has a set of types, enforcing proper usage usually requires some context. Another example is duck typing, where the type of an element can change depending on context, operator overloading is yet another case where correct usage and final function are determined based on the context. Java provides an excellent example, where the + operator is both numerical addition and concatenation of strings, although there are other data structures involved in the inner workings of a compiler, the AST performs a unique function
23.
Tree traversal
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In computer science, tree traversal is a form of graph traversal and refers to the process of visiting each node in a tree data structure, exactly once. Such traversals are classified by the order in which the nodes are visited, the following algorithms are described for a binary tree, but they may be generalized to other trees as well. Unlike linked lists, one-dimensional arrays and other data structures. They may be traversed in depth-first or breadth-first order, there are three common ways to traverse them in depth-first order, in-order, pre-order and post-order. Beyond these basic traversals, various more complex or hybrid schemes are possible, traversing a tree involves iterating over all nodes in some manner. Because from a given node there is more than one possible next node, then, assuming sequential computation and this is often done via a stack or queue. Depth-first search is easily implemented via a stack, including recursively, while breadth-first search is easily implemented via a queue and these searches are referred to as depth-first search, as the search tree is deepened as much as possible on each child before going to the next sibling. When this step is finished you are back at N again, when this step is finished you are back at N again. We may do things in any order. If we do before, we call it left-to-right traversal, otherwise we call it right-to-left traversal, the following methods show left-to-right traversal Check if the current node is empty / null. Display the data part of the root, traverse the left subtree by recursively calling the pre-order function. Traverse the right subtree by recursively calling the pre-order function, Check if the current node is empty / null. Traverse the left subtree by recursively calling the in-order function, display the data part of the root. Traverse the right subtree by recursively calling the in-order function, in a search tree, in-order traversal retrieves data in sorted order. Check if the current node is empty / null, traverse the left subtree by recursively calling the post-order function. Traverse the right subtree by recursively calling the post-order function, display the data part of the root. The trace of a traversal is called a sequentialisation of the tree, the traversal trace is a list of each visited root. No one sequentialisation according to pre-, in- or post-order describes the tree uniquely
24.
Burroughs large systems
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In the 1970s, Burroughs Corporation was organized into three divisions with very different product line architectures for high-end, mid-range, and entry-level business computer systems. Each divisions product line grew from a different concept for how to optimize a computers instruction set for particular programming languages, the Burroughs Large Systems Group designed large mainframes using stack machine instruction sets with dense syllables and 48-bit data words. The first such design was the B5000 in 1961 and it was optimized for running ALGOL60 extremely well, using simple compilers. Subsequent major redesigns include the B6500/B6700 line and its successors, Burroughs Large Systems referred to all of these product lines together, in contrast to the COBOL-optimized Medium Systems or the flexible-architecture Small Systems. While the B5000 architecture is dead, it inspired the B6500, the third and largest line, the B8500, had no commercial success. In addition to a proprietary CMOS processor design Unisys also uses Intel Xeon processors and runs MCP, Microsoft Windows, the first member of the first series, the B5000, was designed beginning in 1961 by a team under the leadership of Robert Barton. It was a machine, well ahead of its time. It has been listed by the influential computing scientist John Mashey as one of the architectures that he admires the most, I always thought it was one of the most innovative examples of combined hardware/software design Ive seen, and far ahead of its time. The B5000 was succeeded by the B5500 and the B5700, while there was no successor to the B5700, the B5000 line heavily influenced the design of the B6500, and Burroughs ported the Master Control Program to that machine. All code automatically reentrant, programmers dont have to do anything more to have any code in any language spread across processors than to use just the two shown simple primitives, however, ESPOL had statements for each of the syllables in the architecture. This was a departure from the computer system design of the time, where a processor and its instruction set would be designed and then handed over to the software people. The B5000, B5500 and B5700 in Word Mode has two different addressing modes, depending on whether it is executing a program or a subroutine. For a main program, the T field of an Operand Call or Descriptor Call syllable is relative to the Program Reference Table. For subroutines, the type of addressing is dependent on the three bits of T and on the Mark Stack FlipFlop, as shown in B5x00 Relative Addressing. The B5000 was designed to exclusively support high-level languages and this was at a time when such languages were just coming to prominence with FORTRAN and then COBOL. FORTRAN and COBOL were considered weaker languages by some, when it comes to modern techniques, so a newer, mostly untried language was adopted. The ALGOL dialect chosen for the B5000 was Elliott ALGOL, first designed and implemented by C. A. R and this was a practical extension of ALGOL with IO instructions and powerful string processing instructions. Hoares famous Turing Award lecture was on this subject, thus the B5000 was based on a very powerful language
25.
Robert S. Barton
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Robert Stanley Bob Barton was recognized as the chief architect of the Burroughs B5000 and other computers such as the B1700, and a co-inventor of dataflow. Bartons thinking has been broadly influential, Barton designed machines at a more abstract level, not tied to the technology constraints of the time. He employed high-level languages and a machine in his design of the Burroughs Corporation B5000 computer. Bartons B5000 design survives in the modern Unisys Burroughs MCP and his work with stack architectures was the first implementation in a mainframe computer. Hewlett-Packard would later use the stack architecture in its HP3000 computers, Barton died on January 28,2009, in Portland, Oregon, at the age of 83. Barton was born in New Britain, Connecticut in 1925 and received his BA in 1948 and his early experience with computers was when he worked in the IBM Applied Science Department in 1951. In 1954, he joined the Shell Oil Company Technical Services, while at Shell, in preparing for a conference in Michigan in 1958, Barton was reading Irving Copis 1954 textbook on Symbolic Logic and saw a reference in it to Polish notation. This made him curious about it and its application to arithmetic expressions and he also then read the works of Jan Łukasiewicz, who had invented Polish Notation back in the early 20th century for use in logic. He managed a system programming group in 1959 which developed an ALGOL-like compiler for Burroughs, the early programming language was known as BALGOL and was implemented for the Burroughs 220 machine. The language and compiler were an early implementation of the International Algebraic Language also known as ALGOL58. After an assignment in Australia in 1963 for Control Data Corporation, from 1968 to 1973 he taught as a professor of Electrical Engineering at the University of Utah with David C. Evans, Ivan Sutherland, and Thomas Stockham, after 1973, he devoted his full-time to Burroughs Systems Research in La Jolla, San Diego, California, working on new computer architectures and systems programming. IEEE1977 W. Wallace McDowell Award Recipient, charter Computer Pioneer by the IEEE Computer Society for his work in Language Directed Architecture. Barton, Robert S. Functional Design of Computers, Communications of the ACM4,405 Barton, a New Approach to the Functional Design of a Digital Computer, Proceedings of the Western Joint Computer Conference, May 1961, pp. 393–396. A Critical Review of the State of Programming Art, AFIPS Joint Computer Conferences, May 1963, “Ideas for Computer Systems Organization, A Personal Survey”, Software Engineering, vol. 1, Academic Press, New York,1970, pp. 7–16, Systems programmers are the high priests of a low cult. Robert S. Barton, IEEE1977 W. Wallace McDowell Award Recipient Waychoff, Richard, Stories about the B5000 and people who were there, April 9,1979 The Early History of Smalltalk by Alan C. Kay History of the School of Computing – University of Utah History of the College of Engineering – University of Utah A Critical Review of the State of the Programming Art
26.
Friden, Inc.
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Friden Calculating Machine Company was an American manufacturer of typewriters and mechanical, later electronic calculators. It was founded by Carl Friden in San Leandro, California, Friden electromechanical calculators were robust and popular. In 1957, Friden purchased the Commercial Controls Corporation of Rochester, the Flexowriter could be attached to Friden calculators and driven by paper tape to produce bills and other form letters which had names of customers and amounts of bills filled in automatically. Friden eventually expanded into production of a few models of early transistorized computers, Friden introduced the first fully transistorized desktop electronic calculator, the model EC-130 in June 1963, designed by Bob Ragen. This machine had a 13-digit capacity and a 5-inch CRT display and it used a magnetostrictive delay line for memory IEEE First-Hand, to save money on expensive transistors. The EC-130 sold for $2,200, about three times the price of comparable electromechanical calculators of the time and it was the first calculator to use reverse Polish notation, which eliminated the need for parentheses to specify the order of operations in complex calculations. The successor model EC-132, introduced in April 1965, added a square root function, in 1965 the company was purchased by the Singer Corporation, but continued operation under the Friden brand name until 1974. In particular, engineer James M. Comstock, working on a pocket calculator project, did not get the necessary priority, Comstock, George E. Hendrie, Gardner, ed. Oral History of George Comstock. Mountain View, California, USA, Computer History Museum, archived from the original on 2017-03-23
27.
HP calculators
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HP calculators are various calculators manufactured by the Hewlett-Packard company over the years. Their desktop models included the HP9800 series, while their handheld models started with the HP-35 and their focus has been on high-end scientific, engineering and complex financial uses. With this in mind, HP built the HP9100 desktop scientific calculator and this new calculator was well received by the customer base, but William Hewlett saw additional opportunities if the desktop calculator could be made small enough to fit into his shirt pocket. He charged his engineers with this goal using the size of his shirt pocket as a guide. The result was the HP-35 calculator and this calculator provided functionality that was revolutionary for a pocket calculator at that time. Through the years, HP released several calculators that varied in their capabilities, programmability. Some of them could be used to control the instruments other Hewlett Packard divisions produced, HP calculators are well known for their use of Reverse Polish Notation. Programmable HP calculators allow users to create their own programs
28.
Hewlett-Packard 9100A
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The Hewlett-Packard 9100A is an early computer, first appearing in 1968. HP called it a desktop calculator because, as Bill Hewlett said, If we had called it a computer and we therefore decided to call it a calculator, and all such nonsense disappeared. The unit was descended from a prototype produced by engineer Tom Osborne, an engineering triumph at the time, the logic circuit was produced without any integrated circuits, the assembly of the CPU having been entirely executed in discrete components. With CRT readout, magnetic storage, and printer, the price was around $5,000. The 9100A was the first scientific calculator by the modern definition, hosted at the Computer History Museum. Chapter 20, The HP Model 9100A computing calculator, steven Leibson interview of Tom Osborne
29.
HP-35
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The HP-35 was Hewlett-Packards first pocket calculator and the worlds first scientific pocket calculator – a calculator with trigonometric and exponential functions. In about 1970 HP co-founder Bill Hewlett challenged his co-workers to create a shirt-pocket sized HP-9100, introduced at US$395, like the HP-9100 it used RPN. The 35 in the name came from the number of keys. The original HP-35 was available from 1972 to 1975 but in 2007 HP announced the release of the retro-look HP 35s in commemoration of the original HP-35, the HP-35 was named an IEEE Milestone in 2009. The calculator used a floating decimal display for numbers that could be displayed in that format. The fifteen-digit LED display was capable of displaying a ten-digit mantissa plus its sign and a decimal point, light emitting diodes were relatively new at the time and were much dimmer than high efficiency diodes developed in subsequent decades. The calculator used three AA-sized NiCd batteries assembled into a removable proprietary battery pack, replacement battery packs are no longer available, leaving existing HP-35 calculators to rely on AC power, or their users to rebuild the battery packs themselves using available cells. An external battery charger was available and the calculator could also run from the charger, internally, the calculator was organized around a serial processor chipset made under contract by Mostek, processing 56-bit floating-point numbers, representing 14-digit BCD numbers. The HP-35 was the start of a family of related calculators with similar packaging, The HP-45 added many more features. It also contained an undocumented timer feature, the timer worked, but was not accurate enough to use as a stopwatch due to lack of a crystal oscillator. The HP-65 added programmability, with storage on magnetic cards. The HP-55, a less expensive follow-on to the HP-65, provided storage for smaller programs, the timer that was already present on the HP-45 was now crystal-controlled to achieve the needed accuracy and explicitly documented. Follow-on calculators used varying mechanical packaging but most were operationally similar, the HP-25 was a smaller, cheaper model of a programmable scientific calculator without magnetic card reader, with features much like the HP-65. The HP-41C was an advance in programmability and capacity. It was the first calculator to offer alphanumeric capabilities for both the display and the keyboard, the later HP-28C and HP-28S added much more memory and a substantially different, more powerful programming metaphor. The HP-35 was 5.8 inches long and 3.2 inches wide, to extend operating time and avoid wearing out the on/off slide switch, users would press the decimal point key to force the display to illuminate just a single LED junction. The HP-35 calculated arithmetic, logarithmic, and trigonomic functions but the complete implementation used only 767 carefully chosen instructions, introduction of the HP-35 and similar scientific calculators by Texas Instruments soon thereafter signaled the demise of the slide rule as a status symbol among science and engineering students. Slide rule holsters rapidly gave way to electronic slide rule holsters,100,000 HP-35 calculators were sold in the first year, and over 300,000 by the time it was discontinued in 1975—3½ years after its introduction
30.
Calculator
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An electronic calculator is a small, portable electronic device used to perform operations ranging from basic arithmetic to complex mathematics. The first solid state electronic calculator was created in the 1960s, building on the history of tools such as the abacus. It was developed in parallel with the computers of the day. The pocket sized devices became available in the 1970s, especially after the first microprocessor and they later became used commonly within the petroleum industry. Modern electronic calculators vary, from cheap, give-away, credit-card-sized models to sturdy desktop models with built-in printers and they became popular in the mid-1970s. By the end of decade, calculator prices had reduced to a point where a basic calculator was affordable to most. In addition to general purpose calculators, there are designed for specific markets. For example, there are scientific calculators which include trigonometric and statistical calculations, some calculators even have the ability to do computer algebra. Graphing calculators can be used to graph functions defined on the real line, as of 2016, basic calculators cost little, but the scientific and graphing models tend to cost more. In 1986, calculators still represented an estimated 41% of the worlds general-purpose hardware capacity to compute information, by 2007, this diminished to less than 0. 05%. Modern 2016 electronic calculators contain a keyboard with buttons for digits and arithmetical operations, most basic calculators assign only one digit or operation on each button, however, in more specific calculators, a button can perform multi-function working with key combinations. Large-sized figures and comma separators are used to improve readability. Various symbols for function commands may also be shown on the display, fractions such as 1⁄3 are displayed as decimal approximations, for example rounded to 0.33333333. Also, some fractions can be difficult to recognize in decimal form, as a result, Calculators also have the ability to store numbers into computer memory. Basic types of these only one number at a time. The variables can also be used for constructing formulas, some models have the ability to extend memory capacity to store more numbers, the extended memory address is termed an array index. Power sources of calculators are, batteries, solar cells or mains electricity, some models even have no turn-off button but they provide some way to put off. Crank-powered calculators were also common in the computer era
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Hewlett-Packard Voyager series
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The Hewlett-Packard Voyager series of calculators were introduced by Hewlett-Packard in 1981. All members of series are programmable, use Reverse Polish Notation. Nearly identical in appearance, each model provided different capabilities and was aimed at different user markets, the HP calculators Voyager series consisted of five models, some of which were manufactured in several variants, HP-10C – basic scientific calculator. The HP-10C is the last and lowest-featured calculator in this line, the 10C was a basic scientific programmable. While a useful general purpose RPN calculator, the HP-11C offered twice as much for only an increase in price. Designed to be an introductory calculator, it was still costly compared to the competition, poor sales led to a very short market life, making it one of the most difficult of the series to find today. The HP-11C is a scientific programmable calculator. The HP-12C is a financial calculator. It was such a model that Hewlett-Packard redesigned it from scratch, added several new functions. Over the course of years, several editions of the calculator were produced as well. The HP-12C is HPs longest and best-selling product, in production since its introduction in 1981. The HP-15C is a scientific programmable with a root-solver and numerical integration. It is also able to handle complex numbers and matrix operations, although long being discontinued its continued popularity among users triggered Hewlett-Packard to offer a HP 15c Limited Edition remake of the calculator in 2011. The HP-16C is a programmers calculator, designed to assist in debugging. It can display numbers in hexadecimal, decimal, octal and binary, a number of specialized functions are provided to assist the programmer, including left- and right-shifting, masking, and bitwise logical operations. HP has never made another programmers calculator, but has incorporated the 16Cs functions in later calculator models and he also wrote parts of the manuals. The HP Voyager series calculator are keystroke programmable, meaning that it can remember and later execute sequences of keystrokes to solve problems of interest to the user. The available programming features differentiate between the various HP Voyager series calculator systems, the HP-12C and its derivatives remains in widespread use today and is still available from Hewlett-Packard
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HP-15C
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The HP-15C is a high-end scientific programmable calculator of Hewlett-Packards Voyager series produced between 1982 and 1989. The HP-15C is a scientific pocket calculator with a root-solver. A member of Hewlett-Packard Voyager series of calculators, it was produced between 1982 and 1989. The calculator is able to handle complex numbers and matrix operations, although out of production, its popularity has led to high prices of $200–400 on the used market and a petition asking HP to restart production. The HP-15C was a replacement for the HP-34C, after showing a prototype labelled HP 15c+ at the HHC2010, HP announced the HP 15c Limited Edition on 1 September 2011. The calculator was released alongside the HP 12c 30th Anniversary Edition, HP-15C, CHS stack lift bug HP-15c Limited Edition, An official emulator for the 15C is commercially available from Hewlett-Packard for Android and iOS devices. In 2012, SwissMicros introduced a miniature clone named DM-15CC approximating the size of a ID-1 credit card and it closely emulates the functionality of the original HP-15C by running the original ROM image in an emulator on an ARM Cortex-M0-based NXP LPC1114 processor. Newer DM-15 models feature a keyboard and more RAM. With a modified firmware, the memory allows for up to 232 registers or 1603 programs steps. A DM-15 Silver Edition in a case is available as well in three color variants. In 2015, SwissMicros introduced the DM-15L, a version of the calculator about the size as the original HP-15C. List of Hewlett-Packard products, Pocket calculators HP calculators Hewlett-Packard HP-15C Owners Handbook, HP 10C Series Technology and Packaging. ELECTRONIC PACKAGING and PRODUCTION Magazine, MARCH,1982
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HP-16C
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The HP-16C Computer Scientist is a programmable pocket calculator that was produced by Hewlett-Packard between 1982 and 1989. It was specifically designed for use by programmers, to assist in debugging. It is a member of the HP Voyager series of programmable calculators and it was the only programmers calculator ever produced by HP, though many later HP calculators have incorporated most of the 16Cs functions. The 16C can display integers in hexadecimal, decimal, octal and binary and it also deals with floating-point decimal numbers. To accommodate long integers, the display can be windowed by shifting it left, for consistency with the computer the programmer is working with, the word size can be set to different values from 1 to 64 bits. Binary-arithmetic operations can be performed as unsigned, ones complement, or twos complement operations and this allows the calculator to emulate the programmers computer. A number of specialized functions are provided to assist the programmer, including left- and right-shifting, masking, apart from programmer functions, the calculators abilities are limited to basic arithmetic, which meant that typical users would also make use of a general scientific calculator. Floating-point numbers are supported for base 10. However, it is far more powerful than contemporary competitors such as the non-programmable computer math calculator Casio CM-100 or the TI Programmer. The base of the 16C features a printed reference chart for many of its functions, though commonplace now, this was still notable in the early 1980s, and is the origin of the C in the model name. Appropriately for a calculator, the 16C, like all other members of the Voyager series, is itself programmable. Up to 203 program steps are available, and up to 16 program/step labels, each step and label uses one byte, which consumes register space in 7 byte increments. Here is a program that computes the factorial of an integer number from 2 to 69. The program takes up 9 bytes, the codes displayed while entering the program generally correspond to the keypad row/column coordinates of the keys pressed. To run the program, enter the argument onto the stack, the result is displayed when the program terminates. There is also an HP-16C emulator application for Android, in 2012, SwissMicros introduced a miniature clone named DM-16CC approximating the size of an ID-1 credit card. It closely emulates the functionality of the original HP-16C by running the original ROM image in an emulator on an ARM Cortex-M0-based NXP LPC1114 processor, newer DM-16 models feature a better keyboard and more RAM. A DM-16 Silver Edition in a case is available as well in three color variants
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HP-12C
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The HP-12C is a financial calculator made by Hewlett-Packard as part of the HP Voyager series. The HP-12C is HPs longest and best-selling product, in production since its introduction in 1981. Due to its operation for key financial calculations, the calculator long ago became the de facto standard among financial professionals. Later HP financial calculators are many times as fast with more functions, the HP-12Cs programing mode is very intuitive and works like a macro operation on a computer. Basically, the one would press in the calculating mode to arrive at a solution are entered in the programing mode along with logical operators if applicable to the solution. After the programing is complete, the macro will run in the mode to save the user steps. There are 99 lines of memory on the HP-12C. There were at least eight hardware revisions of the HP-12C since 1981, over its lifespan, the proprietary silicon on sapphire HP Nut processors technology has been redesigned to integrate all the circuitry into a single chip and to refresh the manufacturing process. In the late 1990s, the CPU was changed to a 3 V process and this has brought advanced possibilities such as flashing new firmware, not previously possible. HP also released a development kit, making it possible to make new. The calculator ran 60-90 times faster on most benchmark operations and this version was colloquially known as the HP-12C+, although HP did not market it as a different product. In contrast to the revision, it supported two parallel CR2032 cells, of which only one was necessary to run the calculator. Based on the processor, a limited HP 12c 30th Anniversary Edition was introduced in 2011. Only 40,000 of this model were made, the internal hardware of the HP-12C changed again in 2015, when the design switched to use an Atmel ATSAM4LC2CA-AU processor with ARM Cortex-M4 core. The calculators part number and physical appearance didnt change except for a Rev 2 plate on the bottom side and it continues to use two parallel CR2032 cells. The firmware reports a 2015 build date, serial numbers starting with PHA, 9CJ, 7CD, or 3CD rule out the older model variant. The 2×3-pin flash port now uses the USB protocol instead of a TTL serial protocol, in addition to this, often referred to as a tool for Old-ie Time-ies, critics of the HP-12C claim its early 1980s technology and style are antiquated. Proponents, however, are quick to note that the HP-12C continues to be both the de jure and de facto standard of high finance
on 16 March 2015. Retrieved 6 December 2015.
