Logo
Unionpedia
Communication
Get it on Google Play
New! Download Unionpedia on your Android™ device!
Free
Faster access than browser!
 

Virtual memory

Index Virtual memory

In computing, virtual memory (also virtual storage) is a memory management technique that provides an "idealized abstraction of the storage resources that are actually available on a given machine" which "creates the illusion to users of a very large (main) memory." The computer's operating system, using a combination of hardware and software, maps memory addresses used by a program, called virtual addresses, into physical addresses in computer memory. [1]

100 relations: Address space, Apple Lisa, Atlas (computer), Atlas Supervisor, Burroughs Corporation, Burroughs large systems, Burroughs MCP, Bus (computing), Cache replacement policies, Central processing unit, Channel I/O, Computer architecture, Computer memory, Computer multitasking, Computing, CP-67, CP/CMS, Data buffer, David Sayre, Deterministic algorithm, Direct memory access, DOS, DOS/360 and successors, Double fault, Drum memory, Electrologica X8, Embedded system, Emulator, Fernando J. Corbató, Fragmentation (computing), GE-600 series, IA-32, IBM, IBM i, IBM System/360 Model 67, IBM System/370, IBM System/38, IEEE Annals of the History of Computing, Input/output, Input–output memory management unit, Intel 80286, Intel 80386, Interrupt, Kilobyte, Linker (computing), Magnetic-core memory, Mainframe computer, Memory address, Memory management, Memory management (operating systems), ..., Memory management unit, Memory segmentation, Memory virtualization, Michigan Terminal System, Microsoft Windows, Minicomputer, Mmap, Multics, MVS, Nord-1, OpenVMS, Operating system, OS/VS1, OS/VS2 (SVS), Overlay (programming), Page (computer memory), Page address register, Page fault, Page replacement algorithm, Page table, Paging, PDP-10, Physical address, Physicist, Process (computing), Processor design, Processor register, Protected mode, RCA Spectra 70, Relocation (computing), SDS 940, Single address space operating system, Supervisor Call instruction, Technical University of Berlin, THE multiprogramming system, Thrashing (computer science), Time Sharing Operating System, Trap (computing), TSS (operating system), University of Manchester, VAX, Victor A. Vyssotsky, Virtual address space, Virtual machine, Windows API, Working set, X86, X86 virtualization, Z/OS, 32-bit. Expand index (50 more) »

Address space

In computing, an address space defines a range of discrete addresses, each of which may correspond to a network host, peripheral device, disk sector, a memory cell or other logical or physical entity.

New!!: Virtual memory and Address space · See more »

Apple Lisa

The Apple Lisa is a desktop computer developed by Apple, released on January 19, 1983.

New!!: Virtual memory and Apple Lisa · See more »

Atlas (computer)

The Atlas Computer was a joint development between the University of Manchester, Ferranti, and Plessey.

New!!: Virtual memory and Atlas (computer) · See more »

Atlas Supervisor

The Atlas Supervisor was the program which managed the allocation of processing resources of Manchester University's Atlas Computer so that the machine was able to act on many tasks and user programs concurrently.

New!!: Virtual memory and Atlas Supervisor · See more »

Burroughs Corporation

The Burroughs Corporation was a major American manufacturer of business equipment.

New!!: Virtual memory and Burroughs Corporation · See more »

Burroughs large systems

In the 1970s, Burroughs Corporation was organized into three divisions with very different product line architectures for high-end, mid-range, and entry-level business computer systems.

New!!: Virtual memory and Burroughs large systems · See more »

Burroughs MCP

The MCP (Master Control Program) is the proprietary operating system of the Burroughs small, medium and large systems, including the Unisys Clearpath/MCP systems.

New!!: Virtual memory and Burroughs MCP · See more »

Bus (computing)

In computer architecture, a bus (a contraction of the Latin omnibus) is a communication system that transfers data between components inside a computer, or between computers.

New!!: Virtual memory and Bus (computing) · See more »

Cache replacement policies

In computing, cache algorithms (also frequently called cache replacement algorithms or cache replacement policies) are optimizing instructionsor algorithmsthat a computer program or a hardware-maintained structure can follow in order to manage a cache of information stored on the computer.

New!!: Virtual memory and Cache replacement policies · See more »

Central processing unit

A central processing unit (CPU) is the electronic circuitry within a computer that carries out the instructions of a computer program by performing the basic arithmetic, logical, control and input/output (I/O) operations specified by the instructions.

New!!: Virtual memory and Central processing unit · See more »

Channel I/O

In computing, channel I/O is a high-performance input/output (I/O) architecture that is implemented in various forms on a number of computer architectures, especially on mainframe computers.

New!!: Virtual memory and Channel I/O · See more »

Computer architecture

In computer engineering, computer architecture is a set of rules and methods that describe the functionality, organization, and implementation of computer systems.

New!!: Virtual memory and Computer architecture · See more »

Computer memory

In computing, memory refers to the computer hardware integrated circuits that store information for immediate use in a computer; it is synonymous with the term "primary storage".

New!!: Virtual memory and Computer memory · See more »

Computer multitasking

In computing, multitasking is the concurrent execution of multiple tasks (also known as processes) over a certain period of time.

New!!: Virtual memory and Computer multitasking · See more »

Computing

Computing is any goal-oriented activity requiring, benefiting from, or creating computers.

New!!: Virtual memory and Computing · See more »

CP-67

CP-67 was the control program portion of CP/CMS, a virtual machine operating system developed for the IBM System/360-67 by IBM's Cambridge Scientific Center.

New!!: Virtual memory and CP-67 · See more »

CP/CMS

CP/CMS (Control Program/Cambridge Monitor System) is a discontinued time-sharing operating system of the late 60s and early 70s, known for its excellent performance and advanced features.

New!!: Virtual memory and CP/CMS · See more »

Data buffer

In computer science, a data buffer (or just buffer) is a region of a physical memory storage used to temporarily store data while it is being moved from one place to another.

New!!: Virtual memory and Data buffer · See more »

David Sayre

David Sayre (March 2, 1924 – February 23, 2012) was an American scientist, credited with the early development of direct methods for protein crystallography and of diffraction microscopy (also called coherent diffraction imaging).

New!!: Virtual memory and David Sayre · See more »

Deterministic algorithm

In computer science, a deterministic algorithm is an algorithm which, given a particular input, will always produce the same output, with the underlying machine always passing through the same sequence of states.

New!!: Virtual memory and Deterministic algorithm · See more »

Direct memory access

Direct memory access (DMA) is a feature of computer systems that allows certain hardware subsystems to access main system memory (Random-access memory), independent of the central processing unit (CPU).

New!!: Virtual memory and Direct memory access · See more »

DOS

DOS is a family of disk operating systems.

New!!: Virtual memory and DOS · See more »

DOS/360 and successors

Disk Operating System/360, also DOS/360, or simply DOS, is a discontinued operating system for IBM mainframes.

New!!: Virtual memory and DOS/360 and successors · See more »

Double fault

On the x86 architecture, a double fault exception occurs if the processor encounters a problem while trying to service a pending interrupt or exception.

New!!: Virtual memory and Double fault · See more »

Drum memory

Drum memory was a magnetic data storage device invented by Gustav Tauschek in 1932 in Austria.

New!!: Virtual memory and Drum memory · See more »

Electrologica X8

The Electrologica X8 (or EL X8) was a digital computer designed as a successor to the Electrologica X1 and manufactured in the Netherlands by Electrologica NV between 1964 and 1968.

New!!: Virtual memory and Electrologica X8 · See more »

Embedded system

An embedded system is a computer system with a dedicated function within a larger mechanical or electrical system, often with real-time computing constraints.

New!!: Virtual memory and Embedded system · See more »

Emulator

In computing, an emulator is hardware or software that enables one computer system (called the host) to behave like another computer system (called the guest).

New!!: Virtual memory and Emulator · See more »

Fernando J. Corbató

Fernando José "Corby" Corbató (born July 1, 1926) is a prominent American computer scientist, notable as a pioneer in the development of time-sharing operating systems.

New!!: Virtual memory and Fernando J. Corbató · See more »

Fragmentation (computing)

In computer storage, fragmentation is a phenomenon in which storage space is used inefficiently, reducing capacity or performance and often both.

New!!: Virtual memory and Fragmentation (computing) · See more »

GE-600 series

The GE-600 series was a family of 36-bit mainframe computers originating in the 1960s, built by General Electric (GE).

New!!: Virtual memory and GE-600 series · See more »

IA-32

IA-32 (short for "Intel Architecture, 32-bit", sometimes also called i386) is the 32-bit version of the x86 instruction set architecture, first implemented in the Intel 80386 microprocessors in 1985.

New!!: Virtual memory and IA-32 · See more »

IBM

The International Business Machines Corporation (IBM) is an American multinational technology company headquartered in Armonk, New York, United States, with operations in over 170 countries.

New!!: Virtual memory and IBM · See more »

IBM i

IBM i is an operating system that runs on IBM Power Systems and on IBM PureSystems.

New!!: Virtual memory and IBM i · See more »

IBM System/360 Model 67

The IBM System/360 Model 67 (S/360-67) was an important IBM mainframe model in the late 1960s.

New!!: Virtual memory and IBM System/360 Model 67 · See more »

IBM System/370

The IBM System/370 (S/370) was a model range of IBM mainframe computers announced on June 30, 1970 as the successors to the System/360 family.

New!!: Virtual memory and IBM System/370 · See more »

IBM System/38

The System/38 was a midrange computer server platform manufactured and sold by the IBM Corporation.

New!!: Virtual memory and IBM System/38 · See more »

IEEE Annals of the History of Computing

The IEEE Annals of the History of Computing is a quarterly peer-reviewed academic journal published by the IEEE Computer Society.

New!!: Virtual memory and IEEE Annals of the History of Computing · See more »

Input/output

In computing, input/output or I/O (or, informally, io or IO) is the communication between an information processing system, such as a computer, and the outside world, possibly a human or another information processing system.

New!!: Virtual memory and Input/output · See more »

Input–output memory management unit

In computing, an input–output memory management unit (IOMMU) is a memory management unit (MMU) that connects a direct-memory-access–capable (DMA-capable) I/O bus to the main memory.

New!!: Virtual memory and Input–output memory management unit · See more »

Intel 80286

The Intel 80286 (also marketed as the iAPX 286 and often called Intel 286) is a 16-bit microprocessor that was introduced on 1 February 1982.

New!!: Virtual memory and Intel 80286 · See more »

Intel 80386

The Intel 80386, also known as i386 or just 386, is a 32-bit microprocessor introduced in 1985.

New!!: Virtual memory and Intel 80386 · See more »

Interrupt

In system programming, an interrupt is a signal to the processor emitted by hardware or software indicating an event that needs immediate attention.

New!!: Virtual memory and Interrupt · See more »

Kilobyte

The kilobyte is a multiple of the unit byte for digital information.

New!!: Virtual memory and Kilobyte · See more »

Linker (computing)

In computing, a linker or link editor is a computer utility program that takes one or more object files generated by a compiler and combines them into a single executable file, library file, or another 'object' file.

New!!: Virtual memory and Linker (computing) · See more »

Magnetic-core memory

Magnetic-core memory was the predominant form of random-access computer memory for 20 years between about 1955 and 1975.

New!!: Virtual memory and Magnetic-core memory · See more »

Mainframe computer

Mainframe computers (colloquially referred to as "big iron") are computers used primarily by large organizations for critical applications; bulk data processing, such as census, industry and consumer statistics, enterprise resource planning; and transaction processing.

New!!: Virtual memory and Mainframe computer · See more »

Memory address

In computing, a memory address is a reference to a specific memory location used at various levels by software and hardware.

New!!: Virtual memory and Memory address · See more »

Memory management

Memory management is a form of resource management applied to computer memory.

New!!: Virtual memory and Memory management · See more »

Memory management (operating systems)

In operating systems, memory management is the function responsible for managing the computer's primary memory.

New!!: Virtual memory and Memory management (operating systems) · See more »

Memory management unit

A memory management unit (MMU), sometimes called paged memory management unit (PMMU), is a computer hardware unit having all memory references passed through itself, primarily performing the translation of virtual memory addresses to physical addresses.

New!!: Virtual memory and Memory management unit · See more »

Memory segmentation

Memory segmentation is the division of a computer's primary memory into segments or sections.

New!!: Virtual memory and Memory segmentation · See more »

Memory virtualization

In computer science, memory virtualization decouples volatile random access memory (RAM) resources from individual systems in the data center, and then aggregates those resources into a virtualized memory pool available to any computer in the cluster.

New!!: Virtual memory and Memory virtualization · See more »

Michigan Terminal System

The Michigan Terminal System (MTS) is one of the first time-sharing computer operating systems.

New!!: Virtual memory and Michigan Terminal System · See more »

Microsoft Windows

Microsoft Windows is a group of several graphical operating system families, all of which are developed, marketed, and sold by Microsoft.

New!!: Virtual memory and Microsoft Windows · See more »

Minicomputer

A minicomputer, or colloquially mini, is a class of smaller computers that was developed in the mid-1960s and sold for much less than mainframe and mid-size computers from IBM and its direct competitors.

New!!: Virtual memory and Minicomputer · See more »

Mmap

In computing, mmap(2) is a POSIX-compliant Unix system call that maps files or devices into memory.

New!!: Virtual memory and Mmap · See more »

Multics

Multics (Multiplexed Information and Computing Service) is an influential early time-sharing operating system, based around the concept of a single-level memory.

New!!: Virtual memory and Multics · See more »

MVS

Multiple Virtual Storage, more commonly called MVS, was the most commonly used operating system on the System/370 and System/390 IBM mainframe computers.

New!!: Virtual memory and MVS · See more »

Nord-1

Nord-1 was Norsk Data's first minicomputer and the first commercially available computer made in Norway.

New!!: Virtual memory and Nord-1 · See more »

OpenVMS

OpenVMS is a closed-source, proprietary computer operating system for use in general-purpose computing.

New!!: Virtual memory and OpenVMS · See more »

Operating system

An operating system (OS) is system software that manages computer hardware and software resources and provides common services for computer programs.

New!!: Virtual memory and Operating system · See more »

OS/VS1

Operating System/Virtual Storage 1, or OS/VS1, is a discontinued IBM mainframe computer operating system designed to be run on IBM System/370 hardware.

New!!: Virtual memory and OS/VS1 · See more »

OS/VS2 (SVS)

Single Virtual Storage (SVS) refers to Release 1 of Operating System/Virtual Storage 2 (OS/VS2); it is the successor system to the MVTBut not 65MP option of Operating System/360.

New!!: Virtual memory and OS/VS2 (SVS) · See more »

Overlay (programming)

In a general computing sense, overlaying means "the process of transferring a block of program code or other data into internal memory, replacing what is already stored".

New!!: Virtual memory and Overlay (programming) · See more »

Page (computer memory)

A page, memory page, or virtual page is a fixed-length contiguous block of virtual memory, described by a single entry in the page table.

New!!: Virtual memory and Page (computer memory) · See more »

Page address register

A page address register (PAR) contains the physical addresses of pages currently held in the main memory of a computer system.

New!!: Virtual memory and Page address register · See more »

Page fault

A page fault (sometimes called #PF, PF or hard fault) is a type of exception raised by computer hardware when a running program accesses a memory page that is not currently mapped by the memory management unit (MMU) into the virtual address space of a process.

New!!: Virtual memory and Page fault · See more »

Page replacement algorithm

In a computer operating system that uses paging for virtual memory management, page replacement algorithms decide which memory pages to page out, sometimes called swap out, or write to disk, when a page of memory needs to be allocated.

New!!: Virtual memory and Page replacement algorithm · See more »

Page table

A page table is the data structure used by a virtual memory system in a computer operating system to store the mapping between virtual addresses and physical addresses.

New!!: Virtual memory and Page table · See more »

Paging

In computer operating systems, paging is a memory management scheme by which a computer stores and retrieves data from secondary storage for use in main memory.

New!!: Virtual memory and Paging · See more »

PDP-10

The PDP-10 is a mainframe computer family manufactured by Digital Equipment Corporation (DEC) from 1966 into the 1980s.

New!!: Virtual memory and PDP-10 · See more »

Physical address

In computing, a physical address (also real address, or binary address), is a memory address that is represented in the form of a binary number on the address bus circuitry in order to enable the data bus to access a particular storage cell of main memory, or a register of memory mapped I/O device.

New!!: Virtual memory and Physical address · See more »

Physicist

A physicist is a scientist who has specialized knowledge in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe.

New!!: Virtual memory and Physicist · See more »

Process (computing)

In computing, a process is an instance of a computer program that is being executed.

New!!: Virtual memory and Process (computing) · See more »

Processor design

Processor design is the design engineering task of creating a processor, a component of computer hardware.

New!!: Virtual memory and Processor design · See more »

Processor register

In computer architecture, a processor register is a quickly accessible location available to a computer's central processing unit (CPU).

New!!: Virtual memory and Processor register · See more »

Protected mode

In computing, protected mode, also called protected virtual address mode, is an operational mode of x86-compatible central processing units (CPUs).

New!!: Virtual memory and Protected mode · See more »

RCA Spectra 70

The RCA Spectra 70 was a line of electronic data processing (EDP) equipment manufactured by the Radio Corporation of America’s computer division beginning in April 1965.

New!!: Virtual memory and RCA Spectra 70 · See more »

Relocation (computing)

Relocation is the process of assigning load addresses to position-dependent, but locatable code of a program and adjusting the code and data in the program to reflect the assigned addresses.

New!!: Virtual memory and Relocation (computing) · See more »

SDS 940

The SDS 940 was Scientific Data Systems' (SDS) first machine designed to directly support time-sharing.

New!!: Virtual memory and SDS 940 · See more »

Single address space operating system

In computer science, a single address space operating system (or SASOS) is an operating system that provides only one globally shared virtual address space for all processes.

New!!: Virtual memory and Single address space operating system · See more »

Supervisor Call instruction

A Supervisor Call instruction (SVC) is a hardware instruction in the System/360 family of IBM mainframe computers up to contemporary zSeries (as well as non-IBM mainframe computers such as the Amdahl 470/V5, 470/V6, 470/V7, 470/V8, 580, 5880, 5990M, and 5990A, and others; Univac 90/60, 90/70 and 90/80, and possibly others; and the Fujitsu M180 (UP), and M200 (MP), and others) used to cause an interrupt to request a service from the operating system.

New!!: Virtual memory and Supervisor Call instruction · See more »

Technical University of Berlin

The Technical University of Berlin (official name Technische Universität Berlin, known as TU Berlin) is a research university located in Berlin, Germany.

New!!: Virtual memory and Technical University of Berlin · See more »

THE multiprogramming system

The THE multiprogramming system or THE OS was a computer operating system designed by a team led by Edsger W. Dijkstra, described in monographs in 1965-66 (Jun 14, 1965) and published in 1968.

New!!: Virtual memory and THE multiprogramming system · See more »

Thrashing (computer science)

In computer science, thrashing occurs when a computer's virtual memory resources become saturated, leading to a constant state of paging (rapidly exchanging data in memory for data on disk), to the exclusion of most application-level processing.

New!!: Virtual memory and Thrashing (computer science) · See more »

Time Sharing Operating System

Time Sharing Operating System, or TSOS, is a discontinued operating system for RCA mainframe computers of the Spectra 70 series.

New!!: Virtual memory and Time Sharing Operating System · See more »

Trap (computing)

In computing and operating systems, a trap, also known as an exception or a fault, is typicallyThere is a wide variation in the nomenclature.

New!!: Virtual memory and Trap (computing) · See more »

TSS (operating system)

The IBM Time Sharing System TSS/360 is a discontinued early time-sharing operating system designed exclusively for a special model of the System/360 line of mainframes, the Model 67.

New!!: Virtual memory and TSS (operating system) · See more »

University of Manchester

The University of Manchester is a public research university in Manchester, England, formed in 2004 by the merger of the University of Manchester Institute of Science and Technology and the Victoria University of Manchester.

New!!: Virtual memory and University of Manchester · See more »

VAX

VAX is a discontinued instruction set architecture (ISA) developed by Digital Equipment Corporation (DEC) in the mid-1970s.

New!!: Virtual memory and VAX · See more »

Victor A. Vyssotsky

Victor Alexander Vyssotsky (Виктор Александрович Высотский; February 26, 1931 - December 24, 2012 in Orleans, Massachusetts) son of the astronomers Alexander N. Vyssotsky (Russian) and Emma Vyssotsky (American) was a mathematician and computer scientist.

New!!: Virtual memory and Victor A. Vyssotsky · See more »

Virtual address space

In computing, a virtual address space (VAS) or address space is the set of ranges of virtual addresses that an operating system makes available to a process.

New!!: Virtual memory and Virtual address space · See more »

Virtual machine

In computing, a virtual machine (VM) is an emulation of a computer system.

New!!: Virtual memory and Virtual machine · See more »

Windows API

The Windows API, informally WinAPI, is Microsoft's core set of application programming interfaces (APIs) available in the Microsoft Windows operating systems.

New!!: Virtual memory and Windows API · See more »

Working set

Working set is a concept in computer science which defines the amount of memory that a process requires in a given time interval.

New!!: Virtual memory and Working set · See more »

X86

x86 is a family of backward-compatible instruction set architectures based on the Intel 8086 CPU and its Intel 8088 variant.

New!!: Virtual memory and X86 · See more »

X86 virtualization

In computing, x86 virtualization refers to hardware virtualization for the x86 architecture.

New!!: Virtual memory and X86 virtualization · See more »

Z/OS

z/OS is a 64-bit operating system for IBM mainframes, produced by IBM.

New!!: Virtual memory and Z/OS · See more »

32-bit

32-bit microcomputers are computers in which 32-bit microprocessors are the norm.

New!!: Virtual memory and 32-bit · See more »

Redirects here:

/dev/drum, Memoria virtual, Memory maps, Paged virtual memory, VSIZE, Virtual Memory, Virtual address translation, Virtual memoy.

References

[1] https://en.wikipedia.org/wiki/Virtual_memory

OutgoingIncoming
Hey! We are on Facebook now! »