An abstract machine, also called an abstract computer, is a theoretical model of a computer hardware or software system. Abstraction of computing processes is used in both the computer science and computer engineering disciplines and usually assumes discrete time paradigm. Jump to: navigation, search A computer is a device or machine for processing information from data according to a program — a compiled list of instructions. ... Wikibooks Wikiversity has more about this subject: School of Computer Science Open Directory Project: Computer Science Downloadable Science and Computer Science books Collection of Computer Science Bibliographies Belief that title science in computer science is inappropriate Categories: Computer science ... Jump to: navigation, search Computer engineering (also sometimes called computer systems engineering) is a specialized discipline that combines electronic engineering and computer science. ... Discrete time is non-continuous time. ... Since the late 1800s, the word paradigm (IPA: ) has referred to a thought pattern in any scientific discipline or other epistemological context. ...

Abstract machines are often used in thought experiments regarding computability or to analyze the complexity of algorithms (see computational complexity theory). A typical abstract machine consists of a definition in terms of input, output, and the set of allowable operations used to turn the former into the latter. The best-known example is the Turing machine. In philosophy, physics, and other fields, a thought experiment (from the German Gedankenexperiment) is an attempt to solve a problem using the power of human imagination. ... Jump to: navigation, search Complexity theory is part of the theory of computation dealing with the resources required during computation to solve a given problem. ... Jump to: navigation, search An artistic representation of a Turing Machine . ...

More complex definitions create abstract machines with full instruction sets, registers and models of memory. One popular model more similar to real modern machines is the RAM model, which allows random access to indexed memory locations. As the performance difference between different levels of cache memory grows, cache-sensitive models such as the external-memory model and cache-oblivious model are growing in importance. An instruction set, or instruction set architecture (ISA), describes the aspects of a computer architecture visible to a programmer, including the native datatypes, instructions, registers, addressing modes, memory architecture, interrupt and exception handling, and external I/O (if any). ... In computer architecture, a processor register is a small amount of very fast computer memory used to speed the execution of computer programs by providing quick access to commonly used values—typically, the values being in the midst of a calculation at a given point in time. ... Jump to: navigation, search This article needs to be cleaned up to conform to a higher standard of quality. ... In computing, the cache-oblivious model is an abstract machine similar to many modern machines, featuring random access and a two-level cache. ...

An abstract machine can also refer to a microprocessor design which has yet to be (or is not intended to be) implemented as hardware. An abstract machine implemented as a software simulation, or for which an interpreter exists, is called a virtual machine. Jump to: navigation, search Microprocessors, including an Intel 80486DX2 and an Intel 80386 A microprocessor (abbreviated as µP or uP) is a computer electronic component made from miniaturized transistors on a single semiconductor integrated circuit (IC) (aka microchip or just chip). ... Interpreter can mean one of the following: In communication, an interpreter is a person whose role is to facilitate dialogue between two parties that do not use the same language. ... In general terms, a virtual machine in computer science is software that creates an environment between the computer platform and the end user in which the end user can operate software. ...

Through the use of abstract machines it is possible to compute the amount of resources (time, memory, etc.) necessary to perform a particular operation without having to construct an actual system to do it.

List of abstract machines

• ABC programming language
• Abstract Machine Notation
• ALF programming language
• Categorical Abstract Machine Language
• Context-free grammar
• Finite automata
• Lambda calculus
• Specification and Design Language
• Warren Abstract Machine
• MMIX

ABC is an imperative general-purpose programming language and programming environment from CWI, Netherlands. ... Abstract Machine Notation (AMN) is a programming language for specifying abstract machines in the B-Method, based on the mathematical theory of Generalised Substitutions. ... ALF is a programming language which combines functional and logic programming techniques. ... CAML may mean: Categorical_Abstract_Machine_Language, a version of ML Collaborative Application Markup Language, an XML-Based markup language used with the Microsoft SharePoint collaborative portal application. ... In linguistics and computer science, a context-free grammar (CFG) is a formal grammar in which every production rule is of the form V → w where V is a non-terminal symbol and w is a string consisting of terminals and/or non-terminals. ... In the theory of computation, a finite state machine (FSM) or finite state automaton (FSA) is an abstract machine that has only a finite, constant amount of memory. ... The lambda calculus is a formal system designed to investigate function definition, function application, and recursion. ... SDL (short for Specification and Description Language) is a specification language targeted at the unambiguous specification and description of the behaviour of reactive and distributed systems. ... In 1983, David H. D. Warren designed an abstract machine for the execution of Prolog consisting of a memory architecture and an instruction set [War83]. This design became known as the Warren Abstract Machine (WAM) and has become the de facto standard target for Prolog compilers. ... MMIX is a 64-bit RISC virtual machine designed by Donald Knuth, with significant contributions by John Hennessy (who designed the MIPS chip) and Dick Sites (who was the architect of the Alpha chip). ...

See also

• Abstraction (computer science)
• Discrete time
• State space