CP/CMS

CP-40 CP[-67]/CMSCMSControl Program-67/Cambridge Monitor SystemCP and CMSCP-67/CMSCP/67CP[-67]/CMSHistoryminidisk
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.wikipedia
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IBM CP-40

CP-40CP-40/CMS
IBM pioneered this idea with its research systems M44/44X (which used partial virtualization) and CP-40 (which used full virtualization).
CP-40 was a research precursor to CP-67, which in turn was part of IBM's then-revolutionary [[CP/CMS|CP[-67]/CMS]] – a virtual machine/virtual memory time-sharing operating system for the IBM System/360 Model 67, and the parent of IBM's VM family.

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.

Virtual machine

virtual machinesVMvirtual server
IBM's CP/CMS, the first systems to allow full virtualization, implemented time sharing by providing each user with a single-user operating system, the Conversational Monitor System (CMS).

Full virtualization

virtualization
IBM pioneered this idea with its research systems M44/44X (which used partial virtualization) and CP-40 (which used full virtualization).
An important example of Virtual Machines, not to be confused with Virtualization implemented by emulation was that provided by the control program of IBM's CP/CMS operating system.

History of CP/CMS

time-sharing operating systems
This effort occurred in a complex political and technical milieu, discussed at some length and supported by first-hand quotes in the Wikipedia article History of CP/CMS.
CP/CMS development occurred in a complex political and technical milieu.

VM (operating system)

VM/CMSVMVM/370
This was a System/370 reimplementation of earlier CP/CMS operating system.

Time-sharing

timesharingtime sharingtime-sharing system
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. In addition to its role as the predecessor of the VM family, CP/CMS played an important role in the development of operating system (OS) theory, the design of IBM's System/370, the time-sharing industry, and the creation of a self-supporting user community that anticipated today's free software movement.

IBM M44/44X

M44/44X
IBM pioneered this idea with its research systems M44/44X (which used partial virtualization) and CP-40 (which used full virtualization).
Unlike CP-40 and later CP/CMS control programs, M44/44X did not implement a complete simulation of the underlying hardware (i.e. full virtualization).

National CSS

Other users, such as National CSS and some academic sites, continued independent development of CP/CMS, rather than switching to VM/370 when it became available.
In 1967, joined by Dick Orenstein (one of the authors of CTSS), the company began exploring the idea of offering time-sharing services based on CP/CMS.

Conversational Monitor System

CMSVM/CMSCambridge Monitor System
CMS was originally developed as part of IBM's CP/CMS operating system, which went into production use in 1967.

IBM System/360 Model 67

IBM System/360-67System/360 Model 67Model 67
After the failure of TSS/360, IBM was surprised by the blossoming of a time-sharing community on the S/360-67 platform (CP/CMS, MTS, MUSIC).

Cambridge Scientific Center

IBM's Cambridge Scientific CenterIBM Cambridge Scientific Center
CP/CMS was built by IBM's Cambridge Scientific Center (CSC), a research and development lab with ties to MIT, under the leadership of Robert Creasy.
It is most notable for creating the CP-40 and the control program portions of CP/CMS, a virtual machine operating system developed for the IBM System/360-67.

Z/VM

Virtual MachineVMzVM
VM/370's successors (such as z/VM) remain in wide use today.
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).

IBM Type-III Library

IBM-LibraType-III software
It was an open-source system, made available in source code form to all IBM customers at no charge – as part of the unsupported IBM Type-III Library.
Source distribution of the VM family of operating systems continued for several decades after it supplanted CP/CMS from the Type-III Library, and TPF was always distributed in source form, apparently continued today with z/TPF.

IBM System/370

System/370S/370IBM/370
IBM reimplemented CP/CMS as its VM/370 product line, released in 1972 when virtual memory was added to the S/370 series.

IBM System/360

System/360IBM 360IBM/360
CP-67, the original virtual machine system, was also known as CP/CMS.

Interactive Data Corporation

IDCInteractive Data
Like competitor National CSS (NCSS), their time-sharing service was based on IBM's CP/CMS Time-sharing software for the IBM System 360 Model 67.

Virtual memory

virtual storagememoryswap
IBM reimplemented CP/CMS as its VM/370 product line, released in 1972 when virtual memory was added to the S/370 series.

Hypervisor

hypervisorsvirtual machine monitorhost machine
Ultimately, in later development at IBM and elsewhere, DIAG instructions were used to create a non-virtualized interface, to what became called a hypervisor.
The term dates to circa 1970; in the earlier CP/CMS (1967) system the term Control Program was used instead.

VP/CSS

It began life in 1968 as a copy of IBM's CP/CMS, which at the time was distributed to IBM customers at no charge, in source code form, without support, as part of the IBM Type-III Library.

Robert Creasy

Bob CreasyR. J. Creasy
CP/CMS was built by IBM's Cambridge Scientific Center (CSC), a research and development lab with ties to MIT, under the leadership of Robert Creasy.
He decided to proceed with his own plan to build a timesharing system, with Bob Creasy leading what became known as the CP-40 Project.

History of IBM

IBMIBM Federal Systems Divisionunbundling of software and services
Before IBM unbundled software from hardware in 1969, the OS (and most other software) was included in the cost of the hardware.

Operating system

operating systemsOScomputer operating system
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. In addition to its role as the predecessor of the VM family, CP/CMS played an important role in the development of operating system (OS) theory, the design of IBM's System/370, the time-sharing industry, and the creation of a self-supporting user community that anticipated today's free software movement.

Free software movement

free software communitysoftware freedomopen source community
In addition to its role as the predecessor of the VM family, CP/CMS played an important role in the development of operating system (OS) theory, the design of IBM's System/370, the time-sharing industry, and the creation of a self-supporting user community that anticipated today's free software movement.