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Computer Multitasking
In computing, multitasking is the concurrent computing, concurrent execution of multiple tasks (also known as Process (computing), processes) over a certain period of time. New tasks can interrupt already started ones before they finish, instead of waiting for them to end. As a result, a computer executes segments of multiple tasks in an interleaved manner, while the tasks share common processing resources such as central processing units (CPUs) and main memory. Multitasking automatically interrupts the running program, saving its state (partial results, memory contents and computer register contents) and loading the saved state of another program and transferring control to it. This "context switch" may be initiated at fixed time intervals (pre-emptive multitasking), or the running program may be coded to signal to the supervisory software when it can be interrupted (cooperative multitasking). Multitasking does not require Parallel computing, parallel execution of multiple task ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thread (computing)
In computer science, a thread of execution is the smallest sequence of programmed instructions that can be managed independently by a scheduler, which is typically a part of the operating system. In many cases, a thread is a component of a process. The multiple threads of a given process may be executed concurrently (via multithreading capabilities), sharing resources such as memory, while different processes do not share these resources. In particular, the threads of a process share its executable code and the values of its dynamically allocated variables and non- thread-local global variables at any given time. The implementation of threads and processes differs between operating systems. History Threads made an early appearance under the name of "tasks" in IBM's batch processing operating system, OS/360, in 1967. It provided users with three available configurations of the OS/360 control system, of which Multiprogramming with a Variable Number of Tasks (MVT) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RISC OS
RISC OS () is an operating system designed to run on ARM architecture, ARM computers. Originally designed in 1987 by Acorn Computers of England, it was made for use in its new line of ARM-based Acorn Archimedes, Archimedes personal computers and was then shipped with other computers produced by the company. Despite the demise of Acorn, RISC OS continues to be developed today by the RISC OS Open community on version 5.0 of the system that was open sourced in 2018. RISC OS is a Modular programming, modular operating system and takes its name from the reduced instruction set computer (RISC) architecture it supports. It incorporates a graphical user interface and a windowing system. Between 1987 and 1998, RISC OS shipped with every ARM-based Acorn computer including the Archimedes line, Acorn's R line (with RISC iX as a dual-boot option), RiscPC, Acorn A7000, A7000, and prototype models such as the Acorn Acorn Computers#NewsPad, NewsPad and Phoebe (computer), Phoebe computer. A vers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Classic Mac OS
Mac OS (originally System Software; retronym: Classic Mac OS) is the series of operating systems developed for the Mac (computer), Macintosh family of personal computers by Apple Computer, Inc. from 1984 to 2001, starting with System 1 and ending with Mac OS 9. The Macintosh operating system is credited with having popularized the graphical user interface concept. It was included with every Macintosh that was sold during the era in which it was developed, and many updates to the system software were done in conjunction with the introduction of new Macintosh systems. Apple released the Macintosh 128K, original Macintosh on January 24, 1984. The System 1, first version of the system software, which had no official name, was partially based on the Lisa OS, which Apple previously released for the Apple Lisa, Lisa computer in 1983. As part of an agreement allowing Xerox to buy Share (finance), shares in Apple at a favorable price, it also used concepts from the PARC (company), Xerox ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microsoft Windows
Windows is a Product lining, product line of Proprietary software, proprietary graphical user interface, graphical operating systems developed and marketed by Microsoft. It is grouped into families and subfamilies that cater to particular sectors of the computing industry – Windows (unqualified) for a consumer or corporate workstation, Windows Server for a Server (computing), server and Windows IoT for an embedded system. Windows is sold as either a consumer retail product or licensed to Original equipment manufacturer, third-party hardware manufacturers who sell products Software bundles, bundled with Windows. The first version of Windows, Windows 1.0, was released on November 20, 1985, as a graphical operating system shell for MS-DOS in response to the growing interest in graphical user interfaces (GUIs). The name "Windows" is a reference to the windowing system in GUIs. The 1990 release of Windows 3.0 catapulted its market success and led to various other product families ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
JES2
The Job Entry Subsystem (JES) is a component of IBM's MVS ( MVS/370 through z/OS) mainframe operating systems that is responsible for managing batch workloads. In modern times, there are two distinct implementations of the Job Entry System called JES2 and JES3. They are designed to provide efficient execution of batch jobs. Starting with z/OS 3.1, released in September 2023, IBM z/OS no longer includes JES3, and comes with JES2 only – JES3 sites must either migrate to JES2, or license JES3plus from Phoenix Software International, who has taken over future support and development of JES3 from IBM. Job processing is divided into several phases to provide parallelism through pipelining. These phases include input processing where jobs are read and interpreted, the execution phase where jobs run, and output processing where job output is printed or stored on DASD. Jobs that are in the same phase of execution are usually said to reside on a particular queue; for example, jobs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CICS
IBM CICS (Customer Information Control System) is a family of mixed-language application servers that provide online business transaction management, transaction management and connectivity for applications on IBM mainframe systems under z/OS and z/VSE. CICS family products are designed as middleware and support rapid, high-volume online transaction processing. A CICS ''transaction'' is a unit of processing initiated by a single request that may affect one or more objects. This processing is usually interactive (screen-oriented), but background transactions are possible. CICS Transaction Server (CICS TS) sits at the head of the CICS family and provides services that extend or replace the functions of the operating system. These services can be more efficient than the generalized operating system services and also simpler for programmers to use, particularly with respect to communication with diverse terminal devices. Applications developed for CICS may be written in a variet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operating System
An operating system (OS) is system software that manages computer hardware and software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for efficient use of the system and may also include accounting software for cost allocation of Scheduling (computing), processor time, mass storage, peripherals, and other resources. For hardware functions such as input and output and memory allocation, the operating system acts as an intermediary between programs and the computer hardware, although the application code is usually executed directly by the hardware and frequently makes system calls to an OS function or is interrupted by it. Operating systems are found on many devices that contain a computerfrom cellular phones and video game consoles to web servers and supercomputers. , Android (operating system), Android is the most popular operating system with a 46% market share, followed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Batch Processing
Computerized batch processing is a method of running software programs called jobs in batches automatically. While users are required to submit the jobs, no other interaction by the user is required to process the batch. Batches may automatically be run at scheduled times as well as being run contingent on the availability of computer resources. History The term "batch processing" originates in the traditional classification of methods of production as job production (one-off production), batch production (production of a "batch" of multiple items at once, one stage at a time), and flow production (mass production, all stages in process at once). Early history Early computers were capable of running only one program at a time. Each user had sole control of the machine for a scheduled period of time. They would arrive at the computer with program and data, often on punched paper cards and magnetic or paper tape, and would load their program, run and debug it, and carry off thei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LEO (computer)
The LEO (Lyons Electronic Office) was a series of early computer systems created by J. Lyons and Co. The first in the series, the LEO I, was the first computer used for commercial business applications. The prototype LEO I was modelled closely on the University of Cambridge, Cambridge EDSAC. Its construction was overseen by Oliver Standingford, Raymond Thompson and David Caminer of J. Lyons and Co. LEO I ran its first business application in 1951. In 1954 Lyons formed LEO Computers Ltd to market LEO I and its successors LEO II and LEO III to other companies. LEO Computers eventually became part of English Electric Company (EEL), (EELM), then English Electric Computers (EEC), where the same team developed the faster LEO 360 and even faster LEO 326 models. It then passed to International Computers Limited (ICL) and ultimately Fujitsu. LEO series computers were still in use until 1981. Origins and initial design J. Lyons and Co. was one of the UK's lead ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bull Gamma 60
The Bull Gamma 60 was a large transistorized mainframe computer designed by Compagnie des Machines Bull. Initially announced in 1957, the first unit shipped in 1960. It holds the distinction of being the world's first Multithreading (computer architecture), multi-threaded computer, and the first to feature an architecture specially designed for Parallel computing, parallelism. The Gamma 60 spearheaded numerous groundbreaking technologies during the early 1960s, notably in multi-programming, utilizing tools that were still in their nascent stages. Upon its release, its architecture garnered significant attention among machine designers, becoming a subject of study alongside contemporary supercomputers and being cited as an example for progress in computer design. Despite its innovations, the Gamma 60's large footprint (close to 4000 sq.ft), high cost, energy consumption, and complexity ultimately resulted in limited commercial success, with about only twenty units sold worldwide. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peripheral
A peripheral device, or simply peripheral, is an auxiliary hardware device that a computer uses to transfer information externally. A peripheral is a hardware component that is accessible to and controlled by a computer but is not a core component of the computer. A peripheral can be categorized based on the direction in which information flows relative to the computer: * The computer receives data from an '' input device''; examples: mouse, keyboard, scanner, game controller, microphone and webcam * The computer sends data to an '' output device''; examples: monitor, printer, headphones, and speakers * The computer sends and receives data via an ''input/output device''; examples: storage device (such as disk drive, solid-state drive, USB flash drive, memory card and tape drive), modem, router, gateway and network adapter Many modern electronic devices, such as Internet-enabled digital watches, video game consoles, smartphones, and tablet computers, have in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
