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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.

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Apple Lisa

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

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Atlas (computer)

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

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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.

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Burroughs Corporation

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

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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.

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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.

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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.

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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.

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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.

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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.

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Computer architecture

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

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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".

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Computer multitasking

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

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

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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.

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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.

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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.

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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).

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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.

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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).

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DOS is a family of disk operating systems.

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DOS/360 and successors

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

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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.

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Drum memory

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

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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.

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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.

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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).

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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.

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Fragmentation (computing)

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

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GE-600 series

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

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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.

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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.

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

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IBM System/360 Model 67

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

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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.

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IBM System/38

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

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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.

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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.

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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.

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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.

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Intel 80386

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

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

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

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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.

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Magnetic-core memory

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

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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.

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Memory address

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

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Memory management

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

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Memory management (operating systems)

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

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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.

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Memory segmentation

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

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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.

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Michigan Terminal System

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

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Microsoft Windows

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

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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.

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

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

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

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

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

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Operating system

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

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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.

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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.

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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".

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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.

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Page address register

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

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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.

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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.

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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.

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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.

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

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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.

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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.

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Process (computing)

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

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Processor design

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

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Processor register

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

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Protected mode

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

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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.

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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.

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SDS 940

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

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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.

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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.

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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.

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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.

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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.

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Time Sharing Operating System

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

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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.

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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.

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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.

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

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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.

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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.

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Virtual machine

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

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Windows API

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

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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.

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

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X86 virtualization

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

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

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

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

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