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.
Multiple Virtual Storage, more commonly called MVS, was the most commonly used operating system on the System/370 and System/390 IBM mainframe computers. IBM developed MVS, along with OS/VS1 and SVS, as a successor to OS/360. It is unrelated to IBM's other mainframe operating system lines, e.g., VSE, VM, TPF.
A mainframe computer, informally called a mainframe or big iron, is a computer used primarily by large organizations for critical applications like bulk data processing for tasks such as censuses, industry and consumer statistics, enterprise resource planning, and large-scale transaction processing. A mainframe computer is large but not as large as a supercomputer and has more processing power than some other classes of computers, such as minicomputers, servers, workstations, and personal computers. Most large-scale computer-system architectures were established in the 1960s, but they continue to evolve. Mainframe computers are often used as servers.
In computing, time-sharing is the sharing of a computing resource among many users at the same time by means of multiprogramming and multi-tasking.
BS2000 is an operating system for IBM 390-compatible mainframe computers developed in the 1970s by Siemens and from early 2000s onward by Fujitsu Technology Solutions.
UNIVAC was a line of electronic digital stored-program computers starting with the products of the Eckert–Mauchly Computer Corporation. Later the name was applied to a division of the Remington Rand company and successor organizations.
Time Sharing Option (TSO) is an interactive time-sharing environment for IBM mainframe operating systems, including OS/360 MVT, OS/VS2 (SVS), MVS, OS/390, and z/OS.
This article presents a timeline of events in the history of computer operating systems from 1951 to the current day. For a narrative explaining the overall developments, see the History of operating systems.
The BUNCH was the nickname for the group of mainframe computer competitors of IBM in the 1970s. The name is derived from the names of the five companies: Burroughs, UNIVAC, NCR, Control Data Corporation (CDC), and Honeywell. These companies were grouped together because the market share of IBM was much higher than all of its competitors put together.
The Univac Series 90 is an obsolete family of mainframe class computer systems from UNIVAC first introduced in 1973. The low end family members included the 90/25, 90/30 and 90/40 that ran the OS/3 operating system. The intermediate members of the family were the 90/60 and 90/70, while the 90/80, announced in 1976, was the high end system. The 90/60 through 90/80 systems all ran the Univac’s virtual memory operating system, VS/9.
VP/CSS was a time-sharing operating system developed by National 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. Through extensive in-house development, in what today would be termed a software fork, National CSS took VP/CSS in a different direction from CP/CMS. Although the two systems would eventually share many capabilities, their technical implementations diverged in substantive ways.
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. It was the successor to the Multiprogramming with a Fixed number of Tasks (MFT) option of System/360's operating system OS/360. OS/VS1, in comparison to its predecessor, supported virtual memory. OS/VS1 was generally available during the 1970s and 1980s, and it is no longer supported by IBM.
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. The Spectra 70 line included several CPU models, various configurations of core memory, mass-storage devices, terminal equipment, and a variety of specialized interface equipment.
A Supervisor Call instruction (SVC) is a hardware instruction used by the System/360 family of IBM mainframe computers up to contemporary zSeries, the Amdahl 470V/5, 470V/6, 470V/7, 470V/8, 580, 5880, 5990M, and 5990A, and others; Univac 90/60, 90/70 and 90/80, and possibly others; the Fujitsu M180 (UP) and M200 (MP), and others; and is also used in the Hercules open source mainframe emulation software. It causes an interrupt to request a service from the operating system. The system routine providing the service is called an SVC routine. SVC is a system call.
The history of IBM mainframe operating systems is significant within the history of mainframe operating systems, because of IBM's long-standing position as the world's largest hardware supplier of mainframe computers. IBM mainframes run operating systems supplied by IBM and by third parties.
OS/360, officially known as IBM System/360 Operating System, is a discontinued batch processing operating system developed by IBM for their then-new System/360 mainframe computer, announced in 1964; it was influenced by the earlier IBSYS/IBJOB and Input/Output Control System (IOCS) packages for the IBM 7090/7094 and even more so by the PR155 Operating System for the IBM 1410/7010 processors. It was one of the earliest operating systems to require the computer hardware to include at least one direct access storage device.
VS/9 is a computer operating system for the UNIVAC Series 90 mainframes, used during the late 1960s through 1980s. The 90/60 and 90/70 were repackaged Univac 9700 computers. After the RCA acquisition by Sperry, it was determined that the RCA TSOS operating system was far more advanced than the Univac counterpart, so the company opted to merge the Univac hardware with the RCA software and introduced the 90/70. The 90/60 was introduced shortly thereafter as a slower, less expensive 90/70. It was not until the introduction of the 90/80 that VS/9 finally had a hardware platform optimized to take full advantage of its capability to allow both interactive and batch operations on the same computer.
EDT is a text editor running on the Unisys VS/9 operating system using the UNIVAC Series 90 mainframe computers, and as of 2013 runs on the Fujitsu BS2000 mainframe computer and operating system. It was developed by RCA for the TSOS operating system for Spectra series mainframes. The RCA version was later sold to Sperry Univac, and was released for the VS/9 operating system.
OS/7 is a discontinued operating system from Sperry Univac for its 90/60 and 90/70 computer systems. The system was first announced in November 1971 for Univac's 9700 system and was originally scheduled for delivery in March 1973. However, the delivery slipped by nearly a year, which impacted the 9700 marketing effort. It was first demonstrated by Univac on the new 90/60 system in October 1973. The official release was then planned for January 1974. OS/7 was abruptly discontinued in 1975 in favor of VS/9, Univac's name for RCA's VMOS operating system.
