1.
Computer programming
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Computer programming is a process that leads from an original formulation of a computing problem to executable computer programs. Source code is written in one or more programming languages, the purpose of programming is to find a sequence of instructions that will automate performing a specific task or solving a given problem. The process of programming thus often requires expertise in many different subjects, including knowledge of the domain, specialized algorithms. Related tasks include testing, debugging, and maintaining the code, implementation of the build system. Software engineering combines engineering techniques with software development practices, within software engineering, programming is regarded as one phase in a software development process. There is a debate on the extent to which the writing of programs is an art form. In general, good programming is considered to be the application of all three, with the goal of producing an efficient and evolvable software solution. Because the discipline covers many areas, which may or may not include critical applications, in most cases, the discipline is self-governed by the entities which require the programming, and sometimes very strict environments are defined. Another ongoing debate is the extent to which the language used in writing computer programs affects the form that the final program takes. Different language patterns yield different patterns of thought and this idea challenges the possibility of representing the world perfectly with language because it acknowledges that the mechanisms of any language condition the thoughts of its speaker community. In the 1880s Herman Hollerith invented the concept of storing data in machine-readable form, however, with the concept of the stored-program computers introduced in 1949, both programs and data were stored and manipulated in the same way in computer memory. Machine code was the language of early programs, written in the set of the particular machine. Assembly languages were developed that let the programmer specify instruction in a text format, with abbreviations for each operation code. However, because a language is little more than a different notation for a machine language. High-level languages allow the programmer to write programs in terms that are more abstract and they harness the power of computers to make programming easier by allowing programmers to specify calculations by entering a formula directly. Programs were mostly still entered using punched cards or paper tape, see computer programming in the punch card era. By the late 1960s, data storage devices and computer terminals became inexpensive enough that programs could be created by typing directly into the computers, text editors were developed that allowed changes and corrections to be made much more easily than with punched cards. Whatever the approach to development may be, the program must satisfy some fundamental properties
2.
Pi
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The number π is a mathematical constant, the ratio of a circles circumference to its diameter, commonly approximated as 3.14159. It has been represented by the Greek letter π since the mid-18th century, being an irrational number, π cannot be expressed exactly as a fraction. Still, fractions such as 22/7 and other numbers are commonly used to approximate π. The digits appear to be randomly distributed, in particular, the digit sequence of π is conjectured to satisfy a specific kind of statistical randomness, but to date no proof of this has been discovered. Also, π is a number, i. e. a number that is not the root of any non-zero polynomial having rational coefficients. This transcendence of π implies that it is impossible to solve the ancient challenge of squaring the circle with a compass, ancient civilizations required fairly accurate computed values for π for practical reasons. It was calculated to seven digits, using techniques, in Chinese mathematics. The extensive calculations involved have also used to test supercomputers. Because its definition relates to the circle, π is found in many formulae in trigonometry and geometry, especially those concerning circles, ellipses, and spheres. Because of its role as an eigenvalue, π appears in areas of mathematics. It is also found in cosmology, thermodynamics, mechanics, attempts to memorize the value of π with increasing precision have led to records of over 70,000 digits. In English, π is pronounced as pie, in mathematical use, the lowercase letter π is distinguished from its capitalized and enlarged counterpart ∏, which denotes a product of a sequence, analogous to how ∑ denotes summation. The choice of the symbol π is discussed in the section Adoption of the symbol π, π is commonly defined as the ratio of a circles circumference C to its diameter d, π = C d The ratio C/d is constant, regardless of the circles size. For example, if a circle has twice the diameter of another circle it will also have twice the circumference, preserving the ratio C/d. This definition of π implicitly makes use of geometry, although the notion of a circle can be extended to any curved geometry. Here, the circumference of a circle is the arc length around the perimeter of the circle, a quantity which can be defined independently of geometry using limits. An integral such as this was adopted as the definition of π by Karl Weierstrass, definitions of π such as these that rely on a notion of circumference, and hence implicitly on concepts of the integral calculus, are no longer common in the literature. One such definition, due to Richard Baltzer, and popularized by Edmund Landau, is the following, the cosine can be defined independently of geometry as a power series, or as the solution of a differential equation
3.
ASCII art
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The term is also loosely used to refer to text based visual art in general. ASCII art can be created with any text editor, and is used with free-form languages. Most examples of ASCII art require a fixed-width font such as Courier for presentation, among the oldest known examples of ASCII art are the creations by computer-art pioneer Kenneth Knowlton from around 1966, who was working for Bell Labs at the time. Studies in Perception I by Ken Knowlton and Leon Harmon from 1966 shows some examples of their early ASCII art, one of the main reasons ASCII art was born was because early printers often lacked graphics ability and thus characters were used in place of graphic marks. ASCII art was used in early e-mail when images could not be embedded. ASCII art can also be used for typesetting initials, since 1867 typewriters have been used for creating visual art. The oldest known preserved example of art is a picture of a butterfly made in 1898 by Flora Stacey. TTY stands for TeleTYpe or TeleTYpewriter and is known as Teleprinter or Teletype. RTTY stands for Radioteletype, character sets such as Baudot code, according to a chapter in the RTTY Handbook, text images have been sent via teletypewriter as early as 1923. However, none of the old RTTY art has been discovered yet, what is known is that text images appeared frequently on radioteletype in the 1960s and the 1970s. In the 1960s, Andries van Dam published a representation of an electronic circuit produced on an IBM1403 line printer, at the same time, Kenneth Knowlton was producing realistic images, also on line printers, by overprinting several characters on top of one another. The widespread usage of ASCII art can be traced to the bulletin board systems of the late 1970s. The limitations of computers of that time necessitated the use of text characters to represent images. Along with ASCIIs use in communication, however, it began to appear in the underground online art groups of the period. An ASCII comic is a form of webcomic which uses ASCII text to create images, in place of images in a regular comic, ASCII art is used, with the text or dialog usually placed underneath. During the 1990s, graphical browsing and variable-width fonts became increasingly popular, ASCII and more importantly, ANSI were staples of the early technological era, terminal systems relied on coherent presentation using color and control signals standard in the terminal protocols. Over the years, warez groups began to enter the ASCII art scene, warez groups usually release. nfo files with their software, cracks or other general software reverse-engineering releases. The ASCII art will usually include the groups name and maybe some ASCII borders on the outsides of the release notes
4.
Pirates of Silicon Valley
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Pirates of Silicon Valley is an original 1999 TNT American drama film, directed by Martyn Burke and starring Noah Wyle as Steve Jobs and Anthony Michael Hall as Bill Gates. Steve Jobs is speaking with director Ridley Scott, about the creation of the 1984 commercial for Apple Computer, Jobs is trying to convey his idea that Were creating a completely new consciousness. Scott is more concerned with the aspects of the commercial. Next in 1997 with Jobs, returning to Apple, and announcing a new deal with Microsoft at the 1997 Macworld Expo and his partner, Steve Wozniak or WOZ, is introduced as one of the two central narrators of the story. Wozniak notes to the audience the resemblance between Big Brother and the image of Bill Gates on the screen behind Jobs during this announcement, asking how they got from there to here, the film turns to flashbacks of his youth with Jobs, prior to the forming of Apple. The earliest flashback is in 1971 and takes place on the U. C, Berkeley campus during the period of the student anti-war movements. Teenagers Steve Jobs and Steve Wozniak are shown caught on the campus during a riot between students and police and they flee and after finding safety, Jobs states to Wozniak, Those guys think theyre revolutionaries. Wozniak then comments that Steve was never like you or me, even when I was in Berkeley, I would see something and just see kilobytes or circuit boards while hed see karma or the meaning of the universe. Using a similar structure, the film turns to a young Bill Gates at Harvard University, in the early 1970s, with classmate Steve Ballmer. As with Wozniak in the segment, Ballmer narrates Gates story. Gates and Allens early work with MITS is juxtaposed against the involvement of Jobs, Jobs and Woz develop Apple Computer in the garage of Jobs family home, with the help of Daniel and Elizabeth. Eventually Mike Markkula invests in the company which allows it to expand, in 1977, Jobs, Woz, and Markkula demo the Apple II at the West Coast Computer Faire. This event is followed by the development of the IBM-PC with the help of Gates, the film also follows Jobs relationship with his high school girlfriend and early Apple employee, Arlene, and the difficulties he had acknowledging the birth and existence of their daughter, Lisa. Around the time his daughter was born, Jobs unveiled his next computer, the Lisa was then followed in 1984 by the, a computer inspired by the Xerox Alto. The main body of the film concludes with a 30th birthday toast in 1985 to Steve Jobs shortly before he was fired by CEO John Sculley. The film ends in 1997, with 42 year old Jobs return to Apple and it also indicates that Jobs is now married, has children, and has reconciled with Lisa. The more I read about Steve in particular, the more I saw him in those Shakespearean terms and he was brilliant, volcanic, obsessive, suspicious, even vicious in a business sense. He was about conquest, always conquest, I said, ‘That’s the sort of movie I want to make
5.
Area
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Area is the quantity that expresses the extent of a two-dimensional figure or shape, or planar lamina, in the plane. Surface area is its analog on the surface of a three-dimensional object. It is the analog of the length of a curve or the volume of a solid. The area of a shape can be measured by comparing the shape to squares of a fixed size, in the International System of Units, the standard unit of area is the square metre, which is the area of a square whose sides are one metre long. A shape with an area of three square metres would have the area as three such squares. In mathematics, the square is defined to have area one. There are several formulas for the areas of simple shapes such as triangles, rectangles. Using these formulas, the area of any polygon can be found by dividing the polygon into triangles, for shapes with curved boundary, calculus is usually required to compute the area. Indeed, the problem of determining the area of plane figures was a motivation for the historical development of calculus. For a solid such as a sphere, cone, or cylinder. Formulas for the areas of simple shapes were computed by the ancient Greeks. Area plays an important role in modern mathematics, in addition to its obvious importance in geometry and calculus, area is related to the definition of determinants in linear algebra, and is a basic property of surfaces in differential geometry. In analysis, the area of a subset of the plane is defined using Lebesgue measure, in general, area in higher mathematics is seen as a special case of volume for two-dimensional regions. Area can be defined through the use of axioms, defining it as a function of a collection of certain plane figures to the set of real numbers and it can be proved that such a function exists. An approach to defining what is meant by area is through axioms, area can be defined as a function from a collection M of special kind of plane figures to the set of real numbers which satisfies the following properties, For all S in M, a ≥0. If S and T are in M then so are S ∪ T and S ∩ T, if S and T are in M with S ⊆ T then T − S is in M and a = a − a. If a set S is in M and S is congruent to T then T is also in M, every rectangle R is in M. If the rectangle has length h and breadth k then a = hk, let Q be a set enclosed between two step regions S and T
6.
Dr. Dobb's Journal
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Dr. Dobbs Journal was a monthly journal published in the United States by United Business Media. It covered topics aimed at computer programmers, when launched in 1975, DDJ was the first regular periodical focused on microcomputer software, rather than hardware. In its last years of publication, it was distributed as a PDF monthly, publication ceased at the end of 2014, with the archived website continuing to be available online. Dennis Allison was a computer consultant on the San Francisco Peninsula. Allison said, Let us stand on each others shoulders, not each others toes, the journal was originally intended to be a three-issue xerographed publication. Titled dr. dobbs journal of Tiny BASIC Calisthenics & Orthodontia it was created to distribute the implementations of Tiny BASIC, the original title was created by Eric Bakalinsky, who did occasional paste-up work for PCC. Dobbs was a contraction of Dennis and Bob and it was at a time when memory was very expensive, so compact coding was important. Microcomputer hobbyists needed to avoid using too many bytes of memory—avoiding overbyte, PCC agreed, and hired Jim Warren as its first editor. He immediately changed the title to Dr. Dobbs Journal of Computer Calisthenics & Orthodontia prior to publishing the first issue in January 1976, Jim Warren was DDJs editor for only about a year and a half. Eventually PCC, the corporation, sold DDJ to a commercial publisher. The newsletters content was originally pure enthusiast material, all of the content came from volunteer contributors, with Steve Wozniak as one of the better known of them. In later years, the magazine received contributions from all over the world working in application development and embedded systems across most programming languages. The magazines focus became more professional, columnists included Michael Swaine, Allen Holub and Verity Stob, the pseudonymous British programmer. The title was shortened to Dr. Dobbs Journal, then changed to Dr. Dobbs Journal of Software Tools as it became more popular. The magazine later reverted to Dr. Dobbs Journal with the line, The World of Software Development. In January 2009 Jonathan Erickson, the editor-in-chief, announced the magazine would cease print publication. A website and monthly digital PDF edition, the primary Dr. Dobbs content streams at the end were the Dr. Dobbs website, Dr. Dobbs Journal, and a weekly newsletter, Dr. Dobbs Update. In addition, Dr. Dobbs continued to run the Jolt Awards and, since 1995, regular bloggers include Scott Ambler, Walter Bright, Andrew Koenig, and Al Williams
7.
Landon Curt Noll
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He was also a member of the Amdahl Six team which discovered another record prime in 1989, this prime remains unusual as a record large prime as it was not a Mersenne prime. Noll was born in Walnut Creek, California, United States, at age 18, he became the youngest person to break the record for the largest known prime. He has held or co-held the record three times and he is also the co-inventor of a system for naming arbitrarily large powers of 10. He also helped start the International Obfuscated C Code Contest, and is a co-inventor of the Fowler Noll Vo hash function and his work includes measuring the Solar parallax during the 2004 Transit of Venus as well as the search for Vulcanoid asteroids. He was also involved in politics as a Sunnyvale, California city council member, landon Curt Nolls home page Noll Primer Prover Bio Amdahl Six How High can you count. International Obfuscated C Code Contest Fowler Noll Vo hash
8.
Bourne shell
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The Bourne shell is a shell, or command-line interpreter, for computer operating systems. The Bourne shell was the shell for Version 7 Unix. Most Unix-like systems continue to have /bin/sh—which will be the Bourne shell, developed by Stephen Bourne at Bell Labs, it was a replacement for the Thompson shell, whose executable file had the same name—sh. It was released in 1977 in the Version 7 Unix release distributed to colleges and universities, although it is used as an interactive command interpreter, it was also intended as a scripting language and contains most of the features that are commonly considered to produce structured programs. Work on the Bourne shell initially started in 1976, first appearing in Version 7 Unix, the Bourne shell superseded the Mashey shell. Some of the goals of the shell were, To allow shell scripts to be used as filters. To provide programmability including control flow and variables, control over all input/output file descriptors. Control over signal handling within scripts, no limits on string lengths when interpreting shell scripts. Rationalize and generalize string quoting mechanism and this allowed context to be established at startup and provided a way for shell scripts to pass context to sub scripts without having to use explicit positional parameters. Here documents using << to embed a block of text within a script. For ~ do ~ done loops, in particular the use of $* to loop over arguments, case ~ in ~ esac selection mechanism, primarily intended to assist argument parsing. Sh provided support for environment variables using keyword parameters and exportable variables and it contains strong provisions for controlling input and output and in its expression matching facilities. Stephen Bournes coding style was influenced by his experience with the ALGOL 68C compiler that he had working on at Cambridge University. Moreover, – although the v7 shell is written in C – Bourne took advantage of some macros to give the C source code an ALGOL68 flavor and these macros inspired the IOCCC – International Obfuscated C Code Contest. Over the years, the Bourne shell was enhanced at AT&T, the various variants are thus called like the respective AT&T Unix version it was released with. As the shell was never versioned, the way to identify it was testing its features. The DMERT shell runs on 3B21D computers still in use in the telecommunications industry, the Korn shell written by David Korn based on the original Bourne Shell source code, was a middle road between the Bourne shell and the C shell. Its syntax was chiefly drawn from the Bourne shell, while its job control features resembled those of the C shell, the functionality of the original Korn Shell was used as a basis for the POSIX shell standard
9.
Arithmetic logic unit
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An arithmetic logic unit is a combinational digital electronic circuit that performs arithmetic and bitwise operations on integer binary numbers. This is in contrast to a floating-point unit, which operates on floating point numbers, an ALU is a fundamental building block of many types of computing circuits, including the central processing unit of computers, FPUs, and graphics processing units. A single CPU, FPU or GPU may contain multiple ALUs, in many designs, the ALU also exchanges additional information with a status register, which relates to the result of the current or previous operations. An ALU has a variety of input and output nets, which are the electrical conductors used to digital signals between the ALU and external circuitry. When an ALU is operating, external circuits apply signals to the ALU inputs and, in response, a basic ALU has three parallel data buses consisting of two input operands and a result output. Each data bus is a group of signals that conveys one binary integer number, typically, the A, B and Y bus widths are identical and match the native word size of the external circuitry. The opcode size is related to the number of different operations the ALU can perform, for example, a four-bit opcode can specify up to sixteen different ALU operations. Generally, an ALU opcode is not the same as a machine language opcode, the status outputs are various individual signals that convey supplemental information about the result of an ALU operation. These outputs are usually stored in registers so they can be used in future ALU operations or for controlling conditional branching. The collection of bit registers that store the status outputs are often treated as a single, multi-bit register, zero, which indicates all bits of output are logic zero. Negative, which indicates the result of an operation is negative. Overflow, which indicates the result of an operation has exceeded the numeric range of output. Parity, which indicates whether an even or odd number of bits in the output are logic one, the status input allows additional information to be made available to the ALU when performing an operation. Typically, this is a bit that is the stored carry-out from a previous ALU operation. An ALU is a logic circuit, meaning that its outputs will change asynchronously in response to input changes. In general, external circuitry controls an ALU by applying signals to its inputs, at the same time, the CPU also routes the ALU result output to a destination register that will receive the sum. The ALUs input signals, which are stable until the next clock, are allowed to propagate through the ALU. When the next clock arrives, the destination register stores the ALU result and, since the ALU operation has completed, a number of basic arithmetic and bitwise logic functions are commonly supported by ALUs
10.
Quine (computing)
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A quine is a non-empty computer program which takes no input and produces a copy of its own source code as its only output. The standard terms for these programs in the computability theory and computer science literature are self-replicating programs, self-reproducing programs, a quine is a fixed point of an execution environment, when the execution environment is viewed as a function. Quines are possible in any Turing complete programming language, as a consequence of Kleenes recursion theorem. For amusement, programmers sometimes attempt to develop the shortest possible quine in any programming language. In some languages, particularly scripting languages, an empty file is a fixed point of the language. Such an empty program, submitted as the worlds smallest self reproducing program, the idea of self-reproducing automata came from the dawn of computing, if not before. John von Neumann himself theorized about them, later, Paul Bratley and Jean Millos article Computer Recreations, Self-Reproducing Automata discussed them in 1972. This program appears below, %BEGIN. THIS IS A SELF-REPRODUCING PROGRAM %ROUTINESPEC R R PRINT SYMBOL R PRINT SYMBOL NEWLINE %CAPTION %END~ %CAPTION %ENDOFPROGRAM~ %ROUTINE R %PRINTTEXT %BEGIN, the following Java code demonstrates the basic structure of a quine. The source code contains an array of itself, which is output twice, once inside quotation marks. The following example is in Javascool, for example, this Ruby quine, Quines, per definition, cannot receive any form of input, including reading a file, which means a quine is considered to be cheating if it looks at its own source code. Ignoring the restriction that quines be non-empty, there are examples of programming languages where an empty program is valid. Such programs generally do nothing, in effect, reproducing the program, the quine concept can be extended to multiple levels or recursion, originating what has been called ouroboros programs, or quine-relays. This should not be confused with Multiquines and this Java program outputs the source for a C++ program that outputs the original Java code. A multiquine consisting of 2 languages would be a program which, when supplied with a user-defined command line argument, would print a second program in language Y. Given the second program in language Y, when run normally, given the second program in language Y, and supplied with a user-defined command line argument, would produce the original program in language X. A biquine could then be seen as a set of two programs, both of which are able to print either of the two, depending on the command line argument supplied. Theoretically, there is no limit on the number of languages in a multiquine, a 5-part multiquine has been produced with Python, Perl, C, NewLISP, and F# and there is also a 25-language multiquine. A radiation-hardened quine is a quine that can have any single character removed and still produce the original program with no missing character
