Editing CP/CMS (section)

==History==
{{Main|History of CP/CMS}}
{{See also|IBM CP-40#Historical notes|History of [[IBM]] mainframe operating systems|System/360|History of [[IBM]]|}}
Fundamental CP/CMS architectural and strategic parameters were established in CP-40, which began production use at IBM's Cambridge Scientific Center in early 1967. 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]].

In a nutshell:

* In the early 1960s, IBM sought to maintain dominance over scientific computing, where time-sharing efforts such as [[Compatible Time-Sharing System|CTSS]] and  MIT's [[Project MAC]] gained focus. But IBM had committed to a huge project, the [[System/360]], which took the company in a different direction.
* The time-sharing community was disappointed with the S/360's lack of time-sharing capabilities. This led to key IBM sales losses at [[Project MAC]] and [[Bell Laboratories]]. IBM's Cambridge Scientific Center (CSC), originally established to support Project MAC, began an effort to regain IBM's credibility in time-sharing, by building a time-sharing operating system for the S/360. This system would eventually become CP/CMS. In the same spirit, IBM designed and released a S/360 model with time-sharing features, the IBM System/360-67, and a time-sharing operating system, [[TSS/360]]. TSS failed; but the 360-67 and CP/CMS succeeded, despite internal political battles over time-sharing, and concerted efforts at IBM to scrap the CP/CMS effort{{Citation needed|date=May 2010}}.
* In 1967, CP/CMS production use began, first on CSC's CP-40, then later on CP-67 at [[Lincoln Laboratories]] and other sites. It was made available via the IBM Type-III Library in 1968. By 1972, CP/CMS had gone through several releases; it was a robust, stable system running on 44 systems; it could support 60 timesharing users on a S/360-67; and at least two commercial timesharing vendors ([[National CSS]] and [[Interactive Data Corporation|IDC]]) were reselling S/360-67 time using CP/CMS technology.
* In 1972, IBM announced the addition of virtual memory to the S/370 series, along with the VM/370 operating system, a reimplementation of CP/CMS for the S/370. This marked the end of CP/CMS releases, although the system continued its independent existence for some time. VM releases continued to include source code for some time and members of the VM community long remained active contributors.