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106-597: While Multiflow's commercial success was small and short-lived, its technical success and the dissemination of its technology and people had a great effect on the future of computer science and the computer industry. Multiflow's computers were arguably the most novel ever to be broadly sold, programmed, and used like conventional computers. (Other novel computers either required novel programming, or represented more incremental steps beyond existing computers.) Along with Cydrome , an attached-VLIW minisupercomputer company that had less commercial success, Multiflow demonstrated that

212-615: A nibble ), usually with additional bits for a sign. Many modern CPUs provide limited support for decimal integers as an extended datatype, providing instructions for converting such values to and from binary values. Depending on the architecture, decimal integers may have fixed sizes (e.g., 7 decimal digits plus a sign fit into a 32-bit word), or may be variable-length (up to some maximum digit size), typically occupying two digits per byte (octet). IPv6 addresses, GUIDs Different CPUs support different integral data types. Typically, hardware will support both signed and unsigned types, but only

318-549: A computer as a group of binary digits (bits). The size of the grouping varies so the set of integer sizes available varies between different types of computers. Computer hardware nearly always provides a way to represent a processor register or memory address as an integer. The value of an item with an integral type is the mathematical integer that it corresponds to. Integral types may be unsigned (capable of representing only non-negative integers) or signed (capable of representing negative integers as well). An integer value

424-570: A discipline, computer science spans a range of topics from theoretical studies of algorithms and the limits of computation to the practical issues of implementing computing systems in hardware and software. CSAB , formerly called Computing Sciences Accreditation Board—which is made up of representatives of the Association for Computing Machinery (ACM), and the IEEE Computer Society (IEEE CS) —identifies four areas that it considers crucial to

530-724: A distinct academic discipline in the 1950s and early 1960s. The world's first computer science degree program, the Cambridge Diploma in Computer Science , began at the University of Cambridge Computer Laboratory in 1953. The first computer science department 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. Although first proposed in 1956,

636-404: A few customer programs contained enough ILP to keep a 28/ busy, when they did the performance was remarkable, since the processor would then initiate close to all 28 operations on average. Each 7/ processor datapath comprised a control unit board, an integer ALU board, and a floating point board. The 14/ added a second integer ALU board and a second floating point board. Before many systems were in

742-646: A former head of the NCR computer division, joined the company in 1985 as its CEO . Multiflow delivered its first working VLIW minisupercomputers in early 1987 to three beta-sites: Grumman Aircraft , Sikorsky Helicopter , and the Supercomputer Research Center. A Trace 14/200 was demonstrated to the public at a supercomputing conference in May, 1987, in Santa Clara, California . Multiflow's first computers were called

848-478: A large deal contemplated with Digital Equipment Corporation came apart. At that point, the board determined that the prospects for successful additional financing, in the amounts necessary to bring Multiflow to maturity, were too unlikely to justify the company's continuation. Multiflow's failure is often blamed anecdotally on “good technology, but bad marketing,” on “good software, but slow, conservative hardware,” on some property of its innovative technology, or even on

954-663: A machine-independent way; others have varying definitions depending on the underlying processor word size. Not all language implementations define variables of all integer sizes, and defined sizes may not even be distinct in a particular implementation. An integer in one programming language may be a different size in a different language, on a different processor, or in an execution context of different bitness; see § Words . Some older computer architectures used decimal representations of integers, stored in binary-coded decimal (BCD) or other format. These values generally require data sizes of 4 bits per decimal digit (sometimes called

1060-650: A major metropolitan air-quality board to a major consumer detergent, food and sundries company, along with the expected heavy industry companies, research laboratories and universities. In 1987, GEI Rechnersysteme GmbH, a division of Daimler-Benz , began distributing Traces in Germany with great success, despite fierce competition from other minisupercomputer companies. In the following three years, Multiflow opened offices or had distributors in most of Western Europe and Japan, and opened offices in many US metropolitan areas. Multiflow ended operations on March 27, 1990, two days after

1166-586: A major research lab. As Multiflow grew, it continued the tradition of hiring highly talented people: as one example, the documentation writer became one of the most influential editors in computer publishing. Multiflow's effect on the computer industry was very much its people in addition to its technology. Computer science Computer science is the study of computation , information , and automation . Computer science spans theoretical disciplines (such as algorithms , theory of computation , and information theory ) to applied disciplines (including

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1272-464: A mathematical discipline argue that computer programs are physical realizations of mathematical entities and programs that can be deductively reasoned through mathematical formal methods . Computer scientists Edsger W. Dijkstra and Tony Hoare regard instructions for computer programs as mathematical sentences and interpret formal semantics for programming languages as mathematical axiomatic systems . A number of computer scientists have argued for

1378-443: A mathematics emphasis and with a numerical orientation consider alignment with computational science . Both types of departments tend to make efforts to bridge the field educationally if not across all research. Despite the word science in its name, there is debate over whether or not computer science is a discipline of science, mathematics, or engineering. Allen Newell and Herbert A. Simon argued in 1975, Computer science

1484-463: A network while using concurrency, this is known as a distributed system. Computers within that distributed system have their own private memory, and information can be exchanged to achieve common goals. This branch of computer science aims to manage networks between computers worldwide. Computer security is a branch of computer technology with the objective of protecting information from unauthorized access, disruption, or modification while maintaining

1590-540: A number of terms for the practitioners of the field of computing were suggested in the Communications of the ACM — turingineer , turologist , flow-charts-man , applied meta-mathematician , and applied epistemologist . Three months later in the same journal, comptologist was suggested, followed next year by hypologist . The term computics has also been suggested. In Europe, terms derived from contracted translations of

1696-495: A particular kind of mathematically based technique for the specification , development and verification of software and hardware systems. The use of formal methods for software and hardware design is motivated by the expectation that, as in other engineering disciplines, performing appropriate mathematical analysis can contribute to the reliability and robustness of a design. They form an important theoretical underpinning for software engineering, especially where safety or security

1802-523: A programmer using the C language incorrectly declares as int a variable that will be used to store values greater than 2 −1, the program will fail on computers with 16-bit integers. That variable should have been declared as long , which has at least 32 bits on any computer. Programmers may also incorrectly assume that a pointer can be converted to an integer without loss of information, which may work on (some) 32-bit computers, but fail on 64-bit computers with 64-bit pointers and 32-bit integers. This issue

1908-512: A significant amount of computer science does not involve the study of computers themselves. Because of this, several alternative names have been proposed. Certain departments of major universities prefer the term computing science , to emphasize precisely that difference. Danish scientist Peter Naur suggested the term datalogy , to reflect the fact that the scientific discipline revolves around data and data treatment, while not necessarily involving computers. The first scientific institution to use

2014-436: A single bit, but is often given a full byte for convenience of addressing and speed of access. A four-bit quantity is known as a nibble (when eating, being smaller than a bite ) or nybble (being a pun on the form of the word byte ). One nibble corresponds to one digit in hexadecimal and holds one digit or a sign code in binary-coded decimal. The term byte initially meant 'the smallest addressable unit of memory'. In

2120-416: A small, fixed set of widths. The table above lists integral type widths that are supported in hardware by common processors. High-level programming languages provide more possibilities. It is common to have a 'double width' integral type that has twice as many bits as the biggest hardware-supported type. Many languages also have bit-field types (a specified number of bits, usually constrained to be less than

2226-410: A specific application. Codes are used for data compression , cryptography , error detection and correction , and more recently also for network coding . Codes are studied for the purpose of designing efficient and reliable data transmission methods. Data structures and algorithms are the studies of commonly used computational methods and their computational efficiency. Programming language theory

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2332-471: A typical datum in a computer has some minimal and maximum possible value. The most common representation of a positive integer is a string of bits , using the binary numeral system . The order of the memory bytes storing the bits varies; see endianness . The width , precision , or bitness of an integral type is the number of bits in its representation. An integral type with n bits can encode 2 numbers; for example an unsigned type typically represents

2438-452: A whole integer whose range is greater than or equal to that of a standard integer on the same machine. In C , it is denoted by long . It is required to be at least 32 bits, and may or may not be larger than a standard integer. A conforming program can assume that it can safely store values between −(2 −1) and 2 −1, but it may not assume that the range is not larger. In the C99 version of

2544-422: A word is thus CPU-specific. Many different word sizes have been used, including 6-, 8-, 12-, 16-, 18-, 24-, 32-, 36-, 39-, 40-, 48-, 60-, and 64-bit. Since it is architectural, the size of a word is usually set by the first CPU in a family, rather than the characteristics of a later compatible CPU. The meanings of terms derived from word , such as longword , doubleword , quadword , and halfword , also vary with

2650-415: Is a branch of computer science that deals with the design, implementation, analysis, characterization, and classification of programming languages and their individual features . It falls within the discipline of computer science, both depending on and affecting mathematics, software engineering, and linguistics . It is an active research area, with numerous dedicated academic journals. Formal methods are

2756-422: Is an empirical discipline. We would have called it an experimental science, but like astronomy, economics, and geology, some of its unique forms of observation and experience do not fit a narrow stereotype of the experimental method. Nonetheless, they are experiments. Each new machine that is built is an experiment. Actually constructing the machine poses a question to nature; and we listen for the answer by observing

2862-484: Is an open problem in the theory of computation. Information theory, closely related to probability and statistics , is related to the quantification of information. This was developed by Claude Shannon to find fundamental limits on signal processing operations such as compressing data and on reliably storing and communicating data. Coding theory is the study of the properties of codes (systems for converting information from one form to another) and their fitness for

2968-475: Is associated in the popular mind with robotic development , but the main field of practical application has been as an embedded component in areas of software development , which require computational understanding. The starting point in the late 1940s was Alan Turing's question " Can computers think? ", and the question remains effectively unanswered, although the Turing test is still used to assess computer output on

3074-543: Is connected to many other fields in computer science, including computer vision , image processing , and computational geometry , and is heavily applied in the fields of special effects and video games . Information can take the form of images, sound, video or other multimedia. Bits of information can be streamed via signals . Its processing is the central notion of informatics, the European view on computing, which studies information processing algorithms independently of

3180-409: Is considered by some to have a much closer relationship with mathematics than many scientific disciplines, with some observers saying that computing is a mathematical science. Early computer science was strongly influenced by the work of mathematicians such as Kurt Gödel , Alan Turing , John von Neumann , Rózsa Péter and Alonzo Church and there continues to be a useful interchange of ideas between

3286-403: Is convenient because there is a perfect one-to-one correspondence between representations and values (in particular, no separate +0 and −0 ), and because addition , subtraction and multiplication do not need to distinguish between signed and unsigned types. Other possibilities include offset binary , sign-magnitude , and ones' complement . Some computer languages define integer sizes in

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3392-508: Is determining what can and cannot be automated. The Turing Award is generally recognized as the highest distinction in computer science. 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, aiding in computations such as multiplication and division. Algorithms for performing computations have existed since antiquity, even before

3498-630: Is generally considered the province of disciplines other than computer science. For example, the study of computer hardware is usually considered part of computer engineering , while the study of commercial computer systems and their deployment is often called information technology or information systems . However, there has been exchange of ideas between the various computer-related disciplines. Computer science research also often intersects other disciplines, such as cognitive science , linguistics , mathematics , physics , biology , Earth science , statistics , philosophy , and logic . Computer science

3604-530: Is in storage at the Computer History Museum . Multiflow also produced the software tools for the systems it built. The systems ran Berkeley Unix . Probably, at the time the Multiflow systems were delivered, no computer that issued instructions longer than a single operation at a time had ever run a compiled mainstream operating system. Yet the entire Unix operating system and the usual tools all ran, with

3710-584: Is intended to organize, store, and retrieve large amounts of data easily. Digital databases are managed using database management systems to store, create, maintain, and search data, through database models and query languages . Data mining is a process of discovering patterns in large data sets. The philosopher of computing Bill Rapaport noted three Great Insights of Computer Science : Programming languages can be used to accomplish different tasks in different ways. Common programming paradigms include: Many languages offer support for multiple paradigms, making

3816-426: Is involved. Formal methods are a useful adjunct to software testing since they help avoid errors and can also give a framework for testing. For industrial use, tool support is required. However, the high cost of using formal methods means that they are usually only used in the development of high-integrity and life-critical systems , where safety or security is of utmost importance. Formal methods are best described as

3922-545: Is mathematical and abstract in spirit, but it derives its motivation from practical and everyday computation. It aims to understand the nature of computation and, as a consequence of this understanding, provide more efficient methodologies. According to Peter Denning, the fundamental question underlying computer science is, "What can be automated?" Theory of computation is focused on answering fundamental questions about what can be computed and what amount of resources are required to perform those computations. In an effort to answer

4028-519: Is of high quality, affordable, maintainable, and fast to build. It is a systematic approach to software design, involving the application of engineering practices to software. Software engineering deals with the organizing and analyzing of software—it does not just deal with the creation or manufacture of new software, but its internal arrangement and maintenance. For example software testing , systems engineering , technical debt and software development processes . Artificial intelligence (AI) aims to or

4134-453: Is often smaller than a standard integer, but this is not required. A conforming program can assume that it can safely store values between −(2 −1) and 2 −1, but it may not assume that the range is not larger. In Java , a short is always a 16-bit integer. In the Windows API , the datatype SHORT is defined as a 16-bit signed integer on all machines. A long integer can represent

4240-472: Is permitted. This can be an issue when exchanging code and data between platforms, or doing direct hardware access. Thus, there are several sets of headers providing platform independent exact width types. The C standard library provides stdint.h ; this was introduced in C99 and C++11. Integer literals can be written as regular Arabic numerals , consisting of a sequence of digits and with negation indicated by

4346-423: Is platform-dependent. In C , it is denoted by int and required to be at least 16 bits. Windows and Unix systems have 32-bit int s on both 32-bit and 64-bit architectures. A short integer can represent a whole number that may take less storage, while having a smaller range, compared with a standard integer on the same machine. In C , it is denoted by short . It is required to be at least 16 bits, and

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4452-575: Is required to synthesize goal-orientated processes such as problem-solving, decision-making, environmental adaptation, learning, and communication found in humans and animals. From its origins in cybernetics and in the Dartmouth Conference (1956), artificial intelligence research has been necessarily cross-disciplinary, drawing on areas of expertise such as applied mathematics , symbolic logic, semiotics , electrical engineering , philosophy of mind , neurophysiology , and social intelligence . AI

4558-491: Is resolved by C99 in stdint.h in the form of intptr_t . The bitness of a program may refer to the word size (or bitness) of the processor on which it runs, or it may refer to the width of a memory address or pointer, which can differ between execution modes or contexts. For example, 64-bit versions of Microsoft Windows support existing 32-bit binaries, and programs compiled for Linux's x32 ABI run in 64-bit mode yet use 32-bit memory addresses. The standard integer size

4664-432: Is the field of study and research concerned with the design and use of computer systems , mainly based on the analysis of the interaction between humans and computer interfaces . HCI has several subfields that focus on the relationship between emotions , social behavior and brain activity with computers . Software engineering is the study of designing, implementing, and modifying the software in order to ensure it

4770-783: Is the field of study concerned with constructing mathematical models and quantitative analysis techniques and using computers to analyze and solve scientific problems. A major usage of scientific computing is simulation of various processes, including computational fluid dynamics , physical, electrical, and electronic systems and circuits, as well as societies and social situations (notably war games) along with their habitats, among many others. Modern computers enable optimization of such designs as complete aircraft. Notable in electrical and electronic circuit design are SPICE, as well as software for physical realization of new (or modified) designs. The latter includes essential design software for integrated circuits . Human–computer interaction (HCI)

4876-482: Is the quick development of this relatively new field requires rapid review and distribution of results, a task better handled by conferences than by journals. Integer (computer science) In computer science, an integer is a datum of integral data type , a data type that represents some range of mathematical integers . Integral data types may be of different sizes and may or may not be allowed to contain negative values. Integers are commonly represented in

4982-411: Is typically specified in the source code of a program as a sequence of digits optionally prefixed with + or −. Some programming languages allow other notations, such as hexadecimal (base 16) or octal (base 8). Some programming languages also permit digit group separators . The internal representation of this datum is the way the value is stored in the computer's memory. Unlike mathematical integers,

5088-632: The C programming language and the C++11 version of C++ , a long long type is supported that has double the minimum capacity of the standard long . This type is not supported by compilers that require C code to be compliant with the previous C++ standard, C++03, because the long long type did not exist in C++03. For an ANSI/ISO compliant compiler, the minimum requirements for the specified ranges, that is, −(2 −1) to 2 −1 for signed and 0 to 2 −1 for unsigned, must be fulfilled; however, extending this range

5194-475: The "technocratic paradigm" (which might be found in engineering approaches, most prominently in software engineering), and the "scientific paradigm" (which approaches computer-related artifacts from the empirical perspective of natural sciences , identifiable in some branches of artificial intelligence ). Computer science focuses on methods involved in design, specification, programming, verification, implementation and testing of human-made computing systems. As

5300-554: The 100th anniversary of the invention of the arithmometer, Torres presented in Paris the Electromechanical Arithmometer , a prototype that demonstrated the feasibility of an electromechanical analytical engine, on which commands could be typed and the results printed automatically. In 1937, one hundred years after Babbage's impossible dream, Howard Aiken convinced IBM, which was making all kinds of punched card equipment and

5406-450: The 1980s eventually succeeded. Multiflow was staffed by engineers, computer scientists, and other computer professionals who were attracted to the combination of a novel and challenging technology, an uphill battle, and the remarkable social experience of working in the most uniformly talented group they were ever likely to be a part of. The system was so novel that its engineering was widely expected to fail. Despite that, even though none of

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5512-451: The 2nd of the only two designs for mechanical analytical engines in history. In 1914, the Spanish engineer Leonardo Torres Quevedo published his Essays on Automatics , and designed, inspired by Babbage, a theoretical electromechanical calculating machine which was to be controlled by a read-only program. The paper also introduced the idea of floating-point arithmetic . In 1920, to celebrate

5618-618: The Analytical Engine, Ada Lovelace wrote, in one of the many notes she included, an algorithm to compute the Bernoulli numbers , which is considered to be the first published algorithm ever specifically tailored for implementation on a computer. Around 1885, Herman Hollerith invented the tabulator , which used punched cards to process statistical information; eventually his company became part of IBM . Following Babbage, although unaware of his earlier work, Percy Ludgate in 1909 published

5724-462: The CPU and OS. Practically all new desktop processors are capable of using 64-bit words, though embedded processors with 8- and 16-bit word size are still common. The 36-bit word length was common in the early days of computers. One important cause of non-portability of software is the incorrect assumption that all computers have the same word size as the computer used by the programmer. For example, if

5830-514: The ELI hardware project, started Multiflow in 1984 after failing to interest any mainstream computer companies in partnering in the ELI project. Originally, Multiflow was to have become a division of the workstation company Apollo Computer , but eventually it sought venture capital funding, closing its first round of financing in January, 1985, when the company already had about 20 employees. Donald E. Eckdahl,

5936-547: The Machine Organization department in IBM's main research center in 1959. Concurrency is a property of systems in which several computations are executing simultaneously, and potentially interacting with each other. A number of mathematical models have been developed for general concurrent computation including Petri nets , process calculi and the parallel random access machine model. When multiple computers are connected in

6042-514: The Trace 7/200 and Trace 14/200. The 7/ in the computer model number signified that the processor could initiate seven operations each cycle, using a 256-bit long instruction composed of 7 32-bit operations and a 32-bit utility field. The seven operations were four integer / memory , two floating , and a branch . The 14/ models had twice as many of each instruction, and thus 512-bit long instruction words. Like many scientific-oriented processors of its day,

6148-473: The Trace had no traditional cache memory . Multiflow also announced a 28/ model at the outset, and eventually these were built and sold to a few customers. The 28/ had 1024-bit instruction words. Having ordinary programs compiled for computers like these was unquestionably revolutionary, as no earlier computer had offered compiled ILP even like that of the 7/ models. The 28/ systems pushed these limits far beyond either academic or industrial conception. While only

6254-546: The UK (as in the School of Informatics, University of Edinburgh ). "In the U.S., however, informatics is linked with applied computing, or computing in the context of another domain." A folkloric quotation, often attributed to—but almost certainly not first formulated by— Edsger Dijkstra , states that "computer science is no more about computers than astronomy is about telescopes." The design and deployment of computers and computer systems

6360-468: The VLIW design style was practical, a conclusion surprising to many. While still controversial, VLIW has since been a force in high-performance embedded systems , and has been finding slow acceptance in general-purpose computing. The VLIW (for Very Long Instruction Word) design style was first proposed by Joseph A. (Josh) Fisher , a Yale University computer science professor, during the period 1979-1981. VLIW

6466-516: The accessibility and usability of the system for its intended users. Historical cryptography is the art of writing and deciphering secret messages. Modern cryptography is the scientific study of problems relating to distributed computations that can be attacked. Technologies studied in modern cryptography include symmetric and asymmetric encryption , digital signatures , cryptographic hash functions , key-agreement protocols , blockchain , zero-knowledge proofs , and garbled circuits . A database

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6572-433: The application of a fairly broad variety of theoretical computer science fundamentals, in particular logic calculi, formal languages , automata theory , and program semantics , but also type systems and algebraic data types to problems in software and hardware specification and verification. Computer graphics is the study of digital visual contents and involves the synthesis and manipulation of image data. The study

6678-410: The binary number system. In 1820, Thomas de Colmar launched the mechanical calculator industry when he invented his simplified arithmometer , the first calculating machine strong enough and reliable enough to be used daily in an office environment. Charles Babbage started the design of the first automatic mechanical calculator , his Difference Engine , in 1822, which eventually gave him the idea of

6784-406: The compiler for advanced research purposes. The Multiflow compiler was written in C . It pre-dated the popular use of C++ (Multiflow was a beta-site for the language). The compiler designers were strong believers in the object-oriented paradigm, however, and the compiler had a rather idiosyncratic style that encapsulated the structures and operations in it. This caused a steep learning curve for

6890-476: The compiler won the ACM Doctoral Dissertation Award in 1985. Encouraged by their compiling progress, Fisher's group started an architecture and hardware design effort called the ELI (Enormously Long Instructions) Project. ELI, which was to have 512-bit instruction words and initiate 10-30 RISC operations per cycle, was never built. Instead, Fisher, Ruttenberg, and John O'Donnell, who had led

6996-517: The computer's memory as is necessary to store the numbers; however, a computer has only a finite amount of storage, so they, too, can only represent a finite subset of the mathematical integers. These schemes support very large numbers; for example one kilobyte of memory could be used to store numbers up to 2466 decimal digits long. A Boolean or Flag type is a type that can represent only two values: 0 and 1, usually identified with false and true respectively. This type can be stored in memory using

7102-455: The densities of the time. (The first VLIW microprocessor was the Philips Life, the ancestor of today's TriMedia , delivered several years later.) Since the founding of Sun and SGI in the early 1980s, no new general-purpose computer company has succeeded without building computers for which there was an existing large software base, and none of the many minisupercomputer startup companies of

7208-471: The design and implementation of hardware and software ). Algorithms and data structures are central to computer science. The theory of computation concerns abstract models of computation and general classes of problems that can be solved using them. The fields of cryptography and computer security involve studying the means for secure communication and preventing security vulnerabilities . Computer graphics and computational geometry address

7314-467: 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 . Leibniz may be considered the first computer scientist and information theorist, because of various reasons, including the fact that he documented

7420-604: The different object-code incompatible models of the Multiflow Traces. (While code from a 7/X00 could run correctly on a 14/X00, the nature of the architecture mandated that it would have to be recompiled to run faster than it did on the 7/.) The compiler was generating correct code by 1985, and by 1987 it was producing code that found significant amounts of ILP. After 1987, with the press of customers and prospects, its development emphasized features and functionality, though performance-oriented improvement continued. The compiler

7526-583: The discipline of computer science: theory of computation , algorithms and data structures , programming methodology and languages , and computer elements and architecture . In addition to these four areas, CSAB also identifies fields such as software engineering, artificial intelligence, computer networking and communication, database systems, parallel computation, distributed computation, human–computer interaction, computer graphics, operating systems, and numerical and symbolic computation as being important areas of computer science. Theoretical computer science

7632-424: The distinction more a matter of style than of technical capabilities. Conferences are important events for computer science research. During these conferences, researchers from the public and private sectors present their recent work and meet. Unlike in most other academic fields, in computer science, the prestige of conference papers is greater than that of journal publications. One proposed explanation for this

7738-459: The distinction of three separate paradigms in computer science. Peter Wegner argued that those paradigms are science, technology, and mathematics. Peter Denning 's working group argued that they are theory, abstraction (modeling), and design. Amnon H. Eden described them as the "rationalist paradigm" (which treats computer science as a branch of mathematics, which is prevalent in theoretical computer science, and mainly employs deductive reasoning),

7844-421: The employees (besides Eckdahl) had ever held senior engineering positions, Trace systems and their software were delivered on time, were robust, and exceeded their promised performance. In great part this was due to the talent level of those attracted to the company, and to the tremendous learning environment it was from the outset. Following Multiflow's closing, its employees went on to have a widespread effect on

7950-511: The expression "automatic information" (e.g. "informazione automatica" in Italian) or "information and mathematics" are often used, e.g. informatique (French), Informatik (German), informatica (Italian, Dutch), informática (Spanish, Portuguese), informatika ( Slavic languages and Hungarian ) or pliroforiki ( πληροφορική , which means informatics) in Greek . Similar words have also been adopted in

8056-407: The field of computer networking , where computers with different byte widths might have to communicate. In modern usage byte almost invariably means eight bits, since all other sizes have fallen into disuse; thus byte has come to be synonymous with octet . The term 'word' is used for a small group of bits that are handled simultaneously by processors of a particular architecture . The size of

8162-399: The field, faster 3rd party floating-point chips became available, and the /200 family was replaced by the object-code incompatible 7/300 and 14/300, and the 14/300 became by far the company's most popular model. In about 1988, a /100 entry level series was introduced as well, but these were essentially /300 systems with a slower clock. All the processors were built using CMOS gate arrays for

8268-457: The first programmable mechanical calculator , his Analytical Engine . 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 punched card system derived from the Jacquard loom " making it infinitely programmable. In 1843, during the translation of a French article on

8374-477: The first question, computability theory examines which computational problems are solvable on various theoretical models of computation . The second question is addressed by computational complexity theory , which studies the time and space costs associated with different approaches to solving a multitude of computational problems. The famous P = NP? problem, one of the Millennium Prize Problems ,

8480-461: The generation of images. Programming language theory considers different ways to describe computational processes, and database theory concerns the management of repositories of data. Human–computer interaction investigates the interfaces through which humans and computers interact, and software engineering focuses on the design and principles behind developing software. Areas such as operating systems , networks and embedded systems investigate

8586-559: The hardware, commanded by long instructions or a similar mechanism. While there had previously been processors that achieved significant amounts of ILP, they had all relied upon code laboriously hand-parallelized by the user, or upon library routines , and thus were not general-purpose computers and did not fit the VLIW paradigm . The practicality of trace scheduling was demonstrated by a compiler built at Yale by Fisher and three of his graduate students, John Ruttenberg, Alexandru Nicolau, and especially John Ellis, whose doctoral dissertation on

8692-414: The industry. The small core group of engineers and scientists, numbering about 20, produced four fellows in major American computer companies (two of whom were Eckert-Mauchly Award winners), several founders of successful startups, and leaders of major development efforts at large companies. The only nontechnical person in the core group, hired out of business school, went on to lead corporate development at

8798-400: The integer ALUs and registers , 3rd-party floating point chips, and medium-scale integrated circuits for the control and other portions. In 1988, the company started development of an ECL /500 family, which was to feature a 14/ that could also be used as a multiprocessor of two 7/ models, but that system was not completed before the company ceased operations. One example Trace system

8904-549: The isolated location of its headquarters. The more likely cause was that its business plan was incompatible with seismic shifts in the computer industry. Building a full-scale, general-purpose computer company seemed to require many hundreds of millions of dollars (US) by 1990. But the killer micro revolution meant there would be a steady march of ever faster and cheaper competition. The economies inherent in microprocessors were inaccessible to startups in general, and incompatible with VLIWs, which would have required too much silicon for

9010-502: The machine in operation and analyzing it by all analytical and measurement means available. It has since been argued that computer science can be classified as an empirical science since it makes use of empirical testing to evaluate the correctness of programs , but a problem remains in defining the laws and theorems of computer science (if any exist) and defining the nature of experiments in computer science. Proponents of classifying computer science as an engineering discipline argue that

9116-507: The many developers who used it after Multiflow's demise, but one that was usually considered a good investment because of the unique combination of ambitious compiling and rock-solid engineering the compiler offered. While a few of Multiflow's sales went to organizations wishing to learn more about the new VLIW design style, most systems were used for simulation in product development environments: mechanical, aerodynamic, defense, crash dynamics, chemical, and some electronic. Customers ranged from

9222-567: The maximum hardware-supported width) and range types (that can represent only the integers in a specified range). Some languages, such as Lisp , Smalltalk , REXX , Haskell , Python , and Raku , support arbitrary precision integers (also known as infinite precision integers or bignums ). Other languages that do not support this concept as a top-level construct may have libraries available to represent very large numbers using arrays of smaller variables, such as Java's BigInteger class or Perl 's " bigint " package. These use as much of

9328-464: The most important superscalar processors of the 1990s. Descendants of the compiler were still in wide use 20 years after it first started generating correct code (notably, Intel's icc "Proton" compiler and the NEC Earth Simulator compiler), and are often used as benchmark targets for new compiler development. MIT and the University of Washington are among the universities that received and used

9434-471: The non-negative values 0 through 2 − 1 . Other encodings of integer values to bit patterns are sometimes used, for example binary-coded decimal or Gray code , or as printed character codes such as ASCII . There are four well-known ways to represent signed numbers in a binary computing system. The most common is two's complement , which allows a signed integral type with n bits to represent numbers from −2 through 2 − 1 . Two's complement arithmetic

9540-407: The past, 5-, 6-, 7-, 8-, and 9-bit bytes have all been used. There have also been computers that could address individual bits ('bit-addressed machine'), or that could only address 16- or 32-bit quantities ('word-addressed machine'). The term byte was usually not used at all in connection with bit- and word-addressed machines. The term octet always refers to an 8-bit quantity. It is mostly used in

9646-473: The practicality of processors for which the compiler could be relied upon to find and specify ILP. VLIW was put forward by Fisher as a way to build general-purpose instruction-level parallel processors exploiting ILP to a degree that would have been impractical using what would later be called superscalar control hardware. Instead, the compiler could, in advance, arrange the ILP to be carried out nearly in lock-step by

9752-478: The principal focus of computer science is studying the properties of computation in general, while the principal focus of software engineering is the design of specific computations to achieve practical goals, making the two separate but complementary disciplines. The academic, political, and funding aspects of computer science tend to depend on whether a department is formed with a mathematical emphasis or with an engineering emphasis. Computer science departments with

9858-615: The principles and design behind complex systems . Computer architecture describes the construction of computer components and computer-operated equipment. Artificial intelligence and machine learning aim to synthesize goal-orientated processes such as problem-solving, decision-making, environmental adaptation, planning and learning found in humans and animals. Within artificial intelligence, computer vision aims to understand and process image and video data, while natural language processing aims to understand and process textual and linguistic data. The fundamental concern of computer science

9964-484: The reliability of computational systems is investigated in the same way as bridges in civil engineering and airplanes in aerospace engineering . They also argue that while empirical sciences observe what presently exists, computer science observes what is possible to exist and while scientists discover laws from observation, no proper laws have been found in computer science and it is instead concerned with creating phenomena. Proponents of classifying computer science as

10070-409: The scale of human intelligence. But the automation of evaluative and predictive tasks has been increasingly successful as a substitute for human monitoring and intervention in domains of computer application involving complex real-world data. Computer architecture, or digital computer organization, is the conceptual design and fundamental operational structure of a computer system. It focuses largely on

10176-559: The term computer came to refer to the machines rather than their human predecessors. 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. In 1945, IBM founded the Watson Scientific Computing Laboratory at Columbia University in New York City . The renovated fraternity house on Manhattan's West Side

10282-743: The term "computer science" appears in a 1959 article in Communications of the ACM , in which Louis Fein argues for the creation of a Graduate School in Computer Sciences analogous to the creation of Harvard Business School in 1921. Louis justifies the name by arguing that, like management science , the subject is applied and interdisciplinary in nature, while having the characteristics typical of an academic discipline. His efforts, and those of others such as numerical analyst George Forsythe , were rewarded: universities went on to create such departments, starting with Purdue in 1962. Despite its name,

10388-561: The term was the Department of Datalogy at the University of Copenhagen, founded in 1969, with Peter Naur being the first professor in datalogy. The term is used mainly in the Scandinavian countries. An alternative term, also proposed by Naur, is data science ; this is now used for a multi-disciplinary field of data analysis, including statistics and databases. In the early days of computing,

10494-443: The two fields in areas such as mathematical logic , category theory , domain theory , and algebra . The relationship between computer science and software engineering is a contentious issue, which is further muddied by disputes over what the term "software engineering" means, and how computer science is defined. David Parnas , taking a cue from the relationship between other engineering and science disciplines, has claimed that

10600-481: The type of information carrier – whether it is electrical, mechanical or biological. This field plays important role in information theory , telecommunications , information engineering and has applications in medical image computing and speech synthesis , among others. What is the lower bound on the complexity of fast Fourier transform algorithms? is one of the unsolved problems in theoretical computer science . Scientific computing (or computational science)

10706-564: The usual portions compiled, on all the company's models. The compiler was particularly noteworthy, as could be expected given Multiflow's technology. The company built a new compiler, in a similar style to that developed at Yale, but industrial-strength and with the incorporation of much commercially-necessary capability. In addition to implementing aggressive trace scheduling, it was known for its reliability, for its incorporation of state-of-the-art optimization , and for its ability to handle simultaneously many different language variants and all of

10812-438: The way by which the central processing unit performs internally and accesses addresses in memory. Computer engineers study computational logic and design of computer hardware, from individual processor components, microcontrollers , personal computers to supercomputers and embedded systems . The term "architecture" in computer literature can be traced to the work of Lyle R. Johnson and Frederick P. Brooks Jr. , members of

10918-440: Was IBM's first laboratory devoted to pure science. The lab is the forerunner of IBM's Research Division, which today operates research facilities around the world. Ultimately, the close relationship between IBM and Columbia University was instrumental in the emergence of a new scientific discipline, with Columbia offering one of the first academic-credit courses in computer science in 1946. Computer science began to be established as

11024-536: Was also in the calculator business to develop his giant programmable calculator, the ASCC/Harvard Mark I , based on Babbage's Analytical Engine, which itself used cards and a central computing unit. When the machine was finished, some hailed it as "Babbage's dream come true". During the 1940s, with the development of new and more powerful computing machines such as the Atanasoff–Berry computer and ENIAC ,

11130-475: Was motivated by a compiler scheduling technique, called trace scheduling , that Fisher had developed as a graduate student at the Courant Institute of Mathematical Sciences of New York University in 1978. Trace scheduling, unlike any prior compiler technique, exposed significant quantities of instruction-level parallelism (ILP) in ordinary computer programs, without laborious hand coding. This implied

11236-574: Was so robust, and so good at exposing ILP independent of the system it was targeted for, that after Multiflow closed, the compiler was licensed by many of the largest computer companies. It has been reported that this included Intel , Hewlett-Packard , Digital Equipment Corporation , Fujitsu , Hughes , HAL Computer Systems , and Silicon Graphics . Other companies known to have licensed the technology include Equator Technologies, Hitachi and NEC . Compilers built starting from that code base were used for advanced development and benchmark reporting for

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