Endgame tablebase
A typical interface for querying a tablebase An endgame tablebase is a computerized database that contains precalculated exhaustive analysis of a chess endgame position. It is typically used by a computer chess engine during play, or by a human or computer that is retrospectively analysing a game that has already been played. The solutions have profoundly advanced the chess community's understanding of endgame theory. Some positions which humans had analyzed as draws were proven to be winnable; the tablebase analysis could find a mate in more than five hundred moves, far beyond the horizon of humans, and beyond the capability of a computer during play. While endgame tablebases for other board games like checkers,[3] chess variants[4] or Nine Men's Morris[5] exist, when a game is not specified, it is assumed to be chess. Background[edit] More recent contributors have included the following people: Generating tablebases[edit] Metrics: Depth to conversion and depth to mate[edit] 1. 2. 3.
Unix
Unix (all-caps UNIX for the trademark) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, developed in the 1970s at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and others.[3] Many clones of Unix have arisen over the years, of which Linux is the most popular, having overtaken the popularity of "true" Unix on server platforms since its inception in the early 1990s. Overview Originally, Unix was meant to be a programmer's workbench to be used for developing software to be run on multiple platforms[8] more than to be used to run application software. The system grew larger as the operating system started spreading in the academic circle, as users added their own tools to the system and shared them with colleagues.[9] History Standards In 1999, in an effort towards compatibility, several Unix system vendors agreed on SVR4's Executable and Linkable Format (ELF) as the standard for binary and object code files. Components
Ken Thompson
American computer scientist, creator of the Unix operating system Early life and education[edit] Thompson was born in New Orleans. Thompson received a Bachelor of Science in 1965 and a Master's degree in 1966, both in Electrical Engineering and Computer Science, from the University of California, Berkeley, where his master's thesis advisor was Elwyn Berlekamp.[4] Career and research[edit] 1970s[edit] Thompson (sitting) and Ritchie working together at a PDP-11 Throughout the 1970s, Thompson and Ritchie collaborated on the Unix operating system; they were so influential on Research Unix that Doug McIlroy later wrote, "The names of Ritchie and Thompson may safely be assumed to be attached to almost everything not otherwise attributed I did the first of two or three versions of UNIX all alone. Feedback from Thompson's Unix development was also instrumental in the development of the C programming language. In 1975, Thompson took a sabbatical from Bell Labs and went to his alma mater, UC Berkeley.
Douglas McIlroy
His seminal work on software componentization,[1] makes him a pioneer of component-based software engineering and software product line engineering. McIlroy (left) with former colleague Dennis Ritchie at the Japan Prize Foundation in May 2011. Dr. McIlroy earned his Bachelor's degree in engineering physics from Cornell University in 1954, and a Ph.D. in applied mathematics from MIT in 1959 for his thesis On the Solution of the Differential Equations of Conical Shells. He taught at MIT from 1954 to 1958. McIlroy joined Bell Laboratories in 1958, from 1965-1986 was head of its Computing Techniques Research Department (the birthplace of the Unix operating system), and thereafter was Distinguished Member of Technical Staff. He was a visiting lecturer at Oxford University from 1967 to 1968. McIlroy retired from Bell Labs in 1997, and serves as an Adjunct Professor in the Dartmouth College Computer Science Department. Quotes[edit] See also[edit] References[edit] External links[edit]
Dennis Ritchie
Personal life[edit] Career[edit] In 1967, Ritchie began working at the Bell Labs Computing Sciences Research Center, and in 1968, he received a PhD from Harvard under the supervision of Patrick C. Fischer, his doctoral dissertation being "Program Structure and Computational Complexity".[6] The C language is widely used today in application, operating system, and embedded system development, and its influence is seen in most modern programming languages. Views on computing[edit] In an interview from 1999, Dennis Ritchie clarifies that he sees Linux and BSD operating systems as a continuation of the basis of the Unix operating system, and as derivatives of Unix:[8] I think the Linux phenomenon is quite delightful, because it draws so strongly on the basis that Unix provided. In the same interview, he states that he views both Unix and Linux as "the continuation of ideas that were started by Ken and me and many others, many years ago Awards[edit] Death and legacy[edit] Notable books[edit]
C (programming language)
C is one of the most widely used programming languages of all time,[8][9] and C compilers are available for the majority of available computer architectures and operating systems. C is an imperative (procedural) language. It was designed to be compiled using a relatively straightforward compiler, to provide low-level access to memory, to provide language constructs that map efficiently to machine instructions, and to require minimal run-time support. C was therefore useful for many applications that had formerly been coded in assembly language, such as in system programming. Despite its low-level capabilities, the language was designed to encourage cross-platform programming. The C language also exhibits the following characteristics: The origin of C is closely tied to the development of the Unix operating system, originally implemented in assembly language on a PDP-7 by Ritchie and Thompson, incorporating several ideas from colleagues. The cover of the book, The C Programming Language
terminology - What is negative code
