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Group Control System(VM)
Group Control System (GCS) is an operating system made by IBM, meant to run as a guest of VM. GCS is an integral component of the discontinued VM/SP (since VM/SP 4), VM/XA SP, VM/ESA and current z/VM IBM System product offerings. Overview GCS's purpose is to provide an environment to run some specific OS/MVS-based applications and networking middleware under VM. To this end, GCS provides a limited simulation of the OS/MVS APIs. While CMS, the usual VM guest, already has OS simulation, it is not extensive enough to run some applications such as VTAM. Specifically, GCS provides OS multitasking support. In order to be able to spread the load over several virtual machines, GCS also implements a notion of group where each group member virtual machine can interact with one another. To implement this, GCS uses several techniques: * A writable shared segment * IUCV communications between virtual machines * A recovery virtual machine, designed to clean up locks in the shared segment ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM Mainframes
IBM mainframes are large computer systems produced by IBM since 1952. During the 1960s and 1970s, IBM dominated the large computer market. Current mainframe computers in IBM's line of business computers are developments of the basic design of the IBM System/360. First and second generation From 1952 into the late 1960s, IBM manufactured and marketed several large computer models, known as the IBM 700/7000 series. The first-generation 700s were based on vacuum tubes, while the later, second-generation 7000s used transistors. These machines established IBM's dominance in electronic data processing ("EDP"). IBM had two model categories: one (701, 704, 709, 7030, 7090, 7094, 7040, 7044) for engineering and scientific use, and one (702, 705, 705-II, 705-III, 7080, 7070, 7072, 7074, 7010) for commercial or data processing use. The two categories, scientific and commercial, generally used common peripherals but had completely different instruction sets, and there were incompatibiliti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proprietary Software
Proprietary software is software that is deemed within the free and open-source software to be non-free because its creator, publisher, or other rightsholder or rightsholder partner exercises a legal monopoly afforded by modern copyright and intellectual property law to exclude the recipient from freely sharing the software or modifying it, and—in some cases, as is the case with some patent-encumbered and EULA-bound software—from making use of the software on their own, thereby restricting his or her freedoms. It is often contrasted with open-source or free software. For this reason, it is also known as non-free software or closed-source software. Types Origin Until the late 1960s computers—large and expensive mainframe computers, machines in specially air-conditioned computer rooms—were usually leased to customers rather than sold. Service and all software available were usually supplied by manufacturers without separate charge until 1969. Computer vendors ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operating System
An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also include accounting software for cost allocation of processor time, mass storage, printing, 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 computer from cellular phones and video game consoles to web servers and supercomputers. The dominant general-purpose personal computer operating system is Microsoft Windows with a market share of around 74.99%. macOS by Apple Inc. is in second place (14.84%), and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VM (operating System)
VM (often: VM/CMS) is a family of IBM virtual machine operating systems used on IBM mainframes System/370, System/390, zSeries, System z and compatible systems, including the Hercules emulator for personal computers. The following versions are known: ;Virtual Machine Facility/370 :VM/370, released in 1972, is a System/370 reimplementation of earlier CP/CMS operating system. ;VM/370 Basic System Extensions Program Product :VM/BSE (BSEPP) is an enhancement to VM/370 that adds support for more devices (such as 3370-type fixed-block-architecture DASD drives), improvements to the CMS environment (such as an improved editor), and some stability enhancements to CP. ;VM/370 System Extensions Program Product :VM/SE (SEPP) is an enhancement to VM/370 that includes the facilities of VM/BSE, as well as a few additional fixes and features. ;Virtual Machine/System Product :VM/SP, a milestone version, replaces VM/370, VM/BSE and VM/SE. Release 1 added EXEC2 and XEDIT System Product Edit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VM/SP
VM (often: VM/CMS) is a family of IBM virtual machine operating systems used on IBM mainframes System/370, System/390, zSeries, System z and compatible systems, including the Hercules emulator for personal computers. The following versions are known: ;Virtual Machine Facility/370 :VM/370, released in 1972, is a System/370 reimplementation of earlier CP/CMS operating system. ;VM/370 Basic System Extensions Program Product :VM/BSE (BSEPP) is an enhancement to VM/370 that adds support for more devices (such as 3370-type fixed-block-architecture DASD drives), improvements to the CMS environment (such as an improved editor), and some stability enhancements to CP. ;VM/370 System Extensions Program Product :VM/SE (SEPP) is an enhancement to VM/370 that includes the facilities of VM/BSE, as well as a few additional fixes and features. ;Virtual Machine/System Product :VM/SP, a milestone version, replaces VM/370, VM/BSE and VM/SE. Release 1 added EXEC2 and XEDIT System Product Edit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VM/ESA
VM (often: VM/CMS) is a family of IBM virtual machine operating systems used on IBM mainframes System/370, System/390, zSeries, System z and compatible systems, including the Hercules emulator for personal computers. The following versions are known: ;Virtual Machine Facility/370 :VM/370, released in 1972, is a System/370 reimplementation of earlier CP/CMS operating system. ;VM/370 Basic System Extensions Program Product :VM/BSE (BSEPP) is an enhancement to VM/370 that adds support for more devices (such as 3370-type fixed-block-architecture DASD drives), improvements to the CMS environment (such as an improved editor), and some stability enhancements to CP. ;VM/370 System Extensions Program Product :VM/SE (SEPP) is an enhancement to VM/370 that includes the facilities of VM/BSE, as well as a few additional fixes and features. ;Virtual Machine/System Product :VM/SP, a milestone version, replaces VM/370, VM/BSE and VM/SE. Release 1 added EXEC2 and XEDIT System Product Edit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Z/VM
z/VM is the current version in IBM's VM family of virtual machine operating systems. z/VM was first released in October 2000 and remains in active use and development . It is directly based on technology and concepts dating back to the 1960s, with IBM's CP/CMS on the IBM System/360-67 (see article History of CP/CMS for historical details). z/VM runs on IBM's IBM Z family of computers. It can be used to support large numbers (thousands) of Linux virtual machines. (See Linux on IBM Z.) On September 16, 2022, IBM released z/VM Version 7.3 which requires z/Architecture, implemented in IBM's EC12, BC12 and later models. See also * z/OS * OpenSolaris for System z * z/TPF * z/VSE * PR/SM * Time-sharing system evolution This article covers the evolution of time-sharing systems, providing links to major early time-sharing operating systems, showing their subsequent evolution. Time-sharing Time-sharing was first proposed in the mid- to late-1950s and first impleme ... References ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middleware
Middleware is a type of computer software that provides services to software applications beyond those available from the operating system. It can be described as "software glue". Middleware makes it easier for software developers to implement communication and input/output, so they can focus on the specific purpose of their application. It gained popularity in the 1980s as a solution to the problem of how to link newer applications to older legacy systems, although the term had been in use since 1968. In distributed applications The term is most commonly used for software that enables communication and management of data in distributed applications. An IETF workshop in 2000 defined middleware as "those services found above the transport (i.e. over TCP/IP) layer set of services but below the application environment" (i.e. below application-level APIs). In this more specific sense ''middleware'' can be described as the dash ("-") in '' client-server'', or the ''-to-'' in ''peer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conversational Monitor System
The Conversational Monitor System (CMS – originally: "Cambridge Monitor System") is a simple interactive single-user operating system. CMS was originally developed as part of IBM's CP/CMS operating system, which went into production use in 1967. CMS is part of IBM's VM family, which runs on IBM mainframe computers. VM was first announced in 1972, and is still in use today as z/VM. CMS runs as a "guest" operating system in a private virtual machine created by the VM ''control program''. The control program plus CMS together create a multi-user time-sharing operating system. History CMS was originally developed as part of IBM's CP/CMS operating system. At the time, the acronym meant "Cambridge Monitor System" (but also: "Console Monitor System"). * CMS first ran under CP-40, a one-off research system using custom hardware at IBM's Cambridge Scientific Center. Production use at CSC began in January 1967. The CMS user interface drew heavily on experience with the influent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VTAM
Virtual Telecommunications Access Method (VTAM) is the IBM subsystem that implements Systems Network Architecture (SNA) for mainframe environments. VTAM provides an application programming interface (API) for communication applications, and controls communication equipment such as adapters and controllers. In modern terminology, VTAM provides a communication stack and device drivers. History VTAM was introduced in 1974 after a series of delays as a major component of SNA along with the 370x Network Control Program (NCP) and Synchronous Data Link Control (SDLC). In IBM terminology, VTAM is an access method software allowing application programs to read and write data to and from external devices. It is called 'virtual' because it was introduced at the time when IBM was introducing virtual storage by upgrading the operating systems of the System/360 series to virtual storage versions. VTAM was supposed to be the successor to the older telecommunications access methods, such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Multitasking
In computing, multitasking is the concurrent execution of multiple tasks (also known as 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 execution of multiple tasks at exactly the same time; instead, it allows more than o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IUCV
Inter User Communication Vehicle (IUCV) is a data transfer mechanism in IBM VM line of operating systems. It was introduced with VM/SP Release 1 in 1980. It allows establishment of point to point communication channels, either between two virtual machines or between a virtual machine and hypervisor services. In effect, IUCV provides a form of message-based interaction between virtual machines that anticipated the client/server interaction between network connected physical machines that emerged later on distributed systems. IUCV is implemented by CP (the VM hypervisor) and controls all aspects of session establishments, message passing and flow control. IUCV basics Initializing IUCV Before a virtual machine can use the IUCV service, it must first indicate the address of an area within its address space where CP will be able to store information regarding pending information or status. Therefore, the DECLARE BUFFER method must be invoked first. The IUCV Path In IUCV terminology, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
