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Op Code
In computing, an opcode (abbreviated from operation code) is an enumerated value that specifies the operation to be performed. Opcodes are employed in hardware devices such as arithmetic logic units (ALUs), central processing units (CPUs), and software instruction sets. In ALUs, the opcode is directly applied to circuitry via an input signal bus. In contrast, in CPUs, the opcode is the portion of a machine language instruction that specifies the operation to be performed. CPUs Opcodes are found in the machine language instructions of CPUs as well as in some abstract computing machines. In CPUs, an opcode may be referred to as an instruction machine code, instruction code, instruction syllable, instruction parcel, or opstring. For any particular processor (which may be a general CPU or a more specialized processing unit), the opcodes are defined by the processor's instruction set architecture (ISA). They can be described using an opcode table. The types of operations may include ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Computing
Computing is any goal-oriented activity requiring, benefiting from, or creating computer, computing machinery. It includes the study and experimentation of algorithmic processes, and the development of both computer hardware, hardware and software. Computing has scientific, engineering, mathematical, technological, and social aspects. Major computing disciplines include computer engineering, computer science, cybersecurity, data science, information systems, information technology, and software engineering. The term ''computing'' is also synonymous with counting and calculation, calculating. In earlier times, it was used in reference to the action performed by Mechanical computer, mechanical computing machines, and before that, to Computer (occupation), human computers. History The history of computing is longer than the history of computing hardware and includes the history of methods intended for pen and paper (or for chalk and slate) with or without the aid of tables. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Assembly Language
In computing, assembly language (alternatively assembler language or symbolic machine code), often referred to simply as assembly and commonly abbreviated as ASM or asm, is any low-level programming language with a very strong correspondence between the instructions in the language and the architecture's machine code instructions. Assembly language usually has one statement per machine instruction (1:1), but constants, comments, assembler directives, symbolic labels of, e.g., memory locations, registers, and macros are generally also supported. The first assembly code in which a language is used to represent machine code instructions is found in Kathleen and Andrew Donald Booth's 1947 work, ''Coding for A.R.C.''. Assembly code is converted into executable machine code by a utility program referred to as an '' assembler''. The term "assembler" is generally attributed to Wilkes, Wheeler and Gill in their 1951 book '' The Preparation of Programs for an Electronic Dig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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The University Of Iowa
The University of Iowa (U of I, UIowa, or Iowa) is a public research university in Iowa City, Iowa, United States. Founded in 1847, it is the oldest and largest university in the state. The University of Iowa is organized into 12 colleges offering more than 200 areas of study and 7 professional degrees. On an urban 1,880-acre campus on the banks of the Iowa River, the University of Iowa is classified among "R1: Doctoral Universities – Very high research activity". In fiscal year 2021, research expenditures at Iowa totaled $818 million. The university was the original developer of the Master of Fine Arts degree, and it operates the Iowa Writers' Workshop, whose alumni include 17 of the university's 46 Pulitzer Prize winners. Iowa is a member of the Association of American Universities and the Universities Research Association. Among public universities in the United States, UI was the first to become coeducational and host a department of religious studies; it also opened the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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University Of Southampton
The University of Southampton (abbreviated as ''Soton'' in post-nominal letters) is a public university, public research university in Southampton, England. Southampton is a founding member of the Russell Group of research-intensive universities in the United Kingdom. The university has seven campuses. The Highfield Campus, main campus is located in the Highfield, Hampshire, Highfield area of Southampton and is supplemented by four other campuses within the city: Avenue Campus housing the School of Humanities, the National Oceanography Centre, Southampton, National Oceanography Centre housing courses in Ocean and Earth Sciences, Southampton General Hospital offering courses in Medicine and Health Sciences, and Boldrewood Campus housing an engineering and maritime technology campus and Lloyd's Register. In addition, the university operates a Winchester School of Art, School of Art based in nearby Winchester and an international branch in Malaysia offering courses in Engineering ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Elsevier North-Holland Inc
Elsevier ( ) is a Dutch academic publishing company specializing in scientific, technical, and medical content. Its products include journals such as ''The Lancet'', '' Cell'', the ScienceDirect collection of electronic journals, '' Trends'', the '' Current Opinion'' series, the online citation database Scopus, the SciVal tool for measuring research performance, the ClinicalKey search engine for clinicians, and the ClinicalPath evidence-based cancer care service. Elsevier's products and services include digital tools for data management, instruction, research analytics, and assessment. Elsevier is part of the RELX Group, known until 2015 as Reed Elsevier, a publicly traded company. According to RELX reports, in 2022 Elsevier published more than 600,000 articles annually in over 2,800 journals. As of 2018, its archives contained over 17 million documents and 40,000 e-books, with over one billion annual downloads. Researchers have criticized Elsevier for its high profit margins an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Fused Operation
In computer programming, an operator is a programming language construct that provides functionality that may not be possible to define as a user-defined function (i.e. sizeof in C) or has syntax different than a function (i.e. infix addition as in a+b). Like other programming language concepts, ''operator'' has a generally accepted, although debatable meaning among practitioners while at the same time each language gives it specific meaning in that context, and therefore the meaning varies by language. Some operators are represented with symbols characters typically not allowed for a function identifier to allow for presentation that is more familiar looking than typical function syntax. For example, a function that tests for greater-than could be named gt, but many languages provide an infix symbolic operator so that code looks more familiar. For example, this: if gt(x, y) then return Can be: if x > y then return Some languages allow a language-defined operator to be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Syllable (computing)
In computing, a syllable is a unit of information that describes the size of data for some digital hardware from the 1960s and 1970s. The size of the unit varies by hardware design in much the same way that word does. The term is not used for modern hardware; standardized terms, such as byte, are used instead. Examples: * 3-bit: some experimental CISC designs * 8-bit: English Electric KDF9 (represented as syllabic octals and also called slob-octals or slobs in this context) and Burroughs large systems (see also: Burroughs B6x00-7x00 instruction set) * 12-bit Before the widespread adoption of ASCII in the late 1960s, six-bit character codes were common and a 12-bit word, which could hold two characters, was a convenient size. This also made it useful for storing a single decimal digit along with a si ...: NCR computers such as the NCR 315 (also called slabs in this context) and Burroughs large systems * 13-bit: Saturn Launch Vehicle Digital Computer (LVDC) and G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Illegal Opcode
An illegal opcode, also called an unimplemented operation, unintended opcode or undocumented instruction, is an instruction to a CPU that is not mentioned in any official documentation released by the CPU's designer or manufacturer, which nevertheless has an effect. Illegal opcodes were common on older CPUs designed during the 1970s, such as the MOS Technology 6502, Intel 8086, and the Zilog Z80. Unlike modern processors, those older processors have a very limited transistor budget, and thus to save space their designers often omitted circuitry to detect invalid opcodes and generate a trap to an error handler. The operation of many of these opcodes happens as a side effect of the wiring of transistors in the CPU, and usually combines functions of the CPU that were not intended to be combined. On old and modern processors, there are also instructions intentionally included in the processor by the manufacturer, but that are not documented in any official specification. Overvi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Gadget (machine Instruction Sequence)
Return-oriented programming (ROP) is a computer security exploit technique that allows an attacker to execute code in the presence of security defenses such as executable-space protection and code signing. In this technique, an attacker gains control of the call stack to hijack program control flow and then executes carefully chosen machine instruction sequences that are already present in the machine's memory, called "gadgets". Each gadget typically ends in a return instruction and is located in a subroutine within the existing program and/or shared library code. Chained together, these gadgets allow an attacker to perform arbitrary operations on a machine employing defenses that thwart simpler attacks. Background Return-oriented programming is an advanced version of a stack smashing attack. Generally, these types of attacks arise when an adversary manipulates the call stack by taking advantage of a bug in the program, often a buffer overrun. In a buffer overrun, a funct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Common Intermediate Language
Common Intermediate Language (CIL), formerly called Microsoft Intermediate Language (MSIL) or Intermediate Language (IL), is the intermediate language binary instruction set defined within the Common Language Infrastructure (CLI) specification. CIL instructions are executed by a CIL-compatible runtime environment such as the Common Language Runtime. Languages which target the CLI compile to CIL. CIL is object-oriented, stack-based bytecode. Runtimes typically just-in-time compile CIL instructions into native code. CIL was originally known as Microsoft Intermediate Language (MSIL) during the beta releases of the .NET languages. Due to standardization of C# and the CLI, the bytecode is now officially known as CIL. Windows Defender virus definitions continue to refer to binaries compiled with it as MSIL. General information During compilation of CLI programming languages, the source code is translated into CIL code rather than into platform- or processor-specific object code. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Lisp (programming Language)
Lisp (historically LISP, an abbreviation of "list processing") is a family of programming languages with a long history and a distinctive, fully parenthesized prefix notation. Originally specified in the late 1950s, it is the second-oldest high-level programming language still in common use, after Fortran. Lisp has changed since its early days, and many dialects have existed over its history. Today, the best-known general-purpose Lisp dialects are Common Lisp, Scheme, Racket, and Clojure. Lisp was originally created as a practical mathematical notation for computer programs, influenced by (though not originally derived from) the notation of Alonzo Church's lambda calculus. It quickly became a favored programming language for artificial intelligence (AI) research. As one of the earliest programming languages, Lisp pioneered many ideas in computer science, including tree data structures, automatic storage management, dynamic typing, conditionals, higher-order function ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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GNU Emacs
GNU Emacs is a text editor and suite of free software tools. Its development began in 1984 by GNU Project founder Richard Stallman, based on the Emacs editor developed for Unix operating systems. GNU Emacs has been a central component of the GNU project and a flagship project of the free software movement. The program's tagline is "the extensible self-documenting text editor." Most functionality in GNU Emacs is implemented in user-accessible Emacs Lisp, allowing deep extensibility directly by users and through community-contributed packages. Its built-in features include a file browser and editor (Dired), an advanced calculator (Calc), an email client and news reader (Gnus), a Language Server Protocol integration, and the productivity system Org-mode. A large community of users have contributed extensions such as the Git interface Magit, the Vim (text editor), Vim emulation layer Evil, several search frameworks, the window manager EXWM, and tools for working with a wide range of p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |