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 tasks or users. It enables multi-tasking by a single user or enables multiple user sessions.
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.
Computer operating systems (OSes) provide a set of functions needed and used by most application programs on a computer, and the links needed to control and synchronize computer hardware. On the first computers, with no operating system, every program needed the full hardware specification to run correctly and perform standard tasks, and its own drivers for peripheral devices like printers and punched paper card readers. The growing complexity of hardware and application programs eventually made operating systems a necessity for everyday use.
The GE-600 series was a family of 36-bit mainframe computers originating in the 1960s, built by General Electric (GE). When GE left the mainframe business the line was sold to Honeywell, which built similar systems into the 1990s as the division moved to Groupe Bull and then NEC.
General Comprehensive Operating System is a family of operating systems oriented toward the 36-bit GE-600 series and Honeywell 6000 series mainframe computers.
Scientific Data Systems (SDS), was an American computer company founded in September 1961 by Max Palevsky, Arthur Rock and Robert Beck, veterans of Packard Bell Corporation and Bendix, along with eleven other computer scientists. SDS was the first to employ silicon transistors, and was an early adopter of integrated circuits in computer design. The company concentrated on larger scientific workload focused machines and sold many machines to NASA during the Space Race. Most machines were both fast and relatively low priced. The company was sold to Xerox in 1969, but dwindling sales due to the oil crisis of 1973–74 caused Xerox to close the division in 1975 at a loss of hundreds of millions of dollars. During the Xerox years the company was officially Xerox Data Systems (XDS), whose machines were the Xerox 500 series.
The SDS Sigma series is a series of third generation computers that were introduced by Scientific Data Systems of the United States in 1966. The first machines in the series are the 16-bit Sigma 2 and the 32-bit Sigma 7; the Sigma 7 was the first 32-bit computer released by SDS. At the time, the only competition for the Sigma 7 was the IBM 360.
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.
In computing, job control refers to the control of multiple tasks or jobs on a computer system, ensuring that they each have access to adequate resources to perform correctly, that competition for limited resources does not cause a deadlock where two or more jobs are unable to complete, resolving such situations where they do occur, and terminating jobs that, for any reason, are not performing as expected.
Plan Calcul was a French governmental program to promote a national or European computer industry and associated research and education activities.
The Universal Time-Sharing System (UTS) is a discontinued operating system for the XDS Sigma series of computers, succeeding Batch Processing Monitor (BPM)/Batch Time-Sharing Monitor (BTM). UTS was announced in 1966, but because of delays did not actually ship until 1971. It was designed to provide multi-programming services for online (interactive) user programs in addition to batch-mode production jobs, symbiont (spooled) I/O, and critical real-time processes. System daemons, called "ghost jobs" were used to run monitor code in user space. The final release, D00, shipped in January, 1973. It was succeeded by the CP-V operating system, which combined UTS with features of the heavily batch-oriented Xerox Operating System (XOS).
The Honeywell Level 6 was a line of 16-bit minicomputers, later upgraded to 32-bit, manufactured by Honeywell, Inc. from the mid 1970s. Honeywell literature for Models 6/06, 6/34 and 6/36 say "Series 60 ". In 1979 the Level 6 was renamed the DPS 6, subsequently DPS 6 Plus and finally DPS 6000.
CP-6 is a discontinued computer operating system, developed by Honeywell, Inc. in 1976, which was a backward-compatible work-alike of the Xerox CP-V, fully rewritten for Honeywell Level/66 hardware. CP-6 was a command line oriented system. A terminal emulator allowed use of PCs as CP-6 terminals.
Interactive Application System (IAS) was a DEC operating system for the PDP-11. It was a fork from RSX-11D.
The CII 10070 is a discontinued computer system from the French company CII. It was part of the first series of computers manufactured in the late 1960s under Plan Calcul.
The CII Iris 80 computer is the most powerful computer made by the French company CII as part of Plan Calcul. It was released in 1970 and had roughly the same capabilities and performance than its main rivals in Europe: the IBM 360/75 and 360/85.
The Iris 50 computer is one of the computers marketed by the French company CII as part of plan Calcul at the end of the 1960s. Designed for the civilian market, it was produced from 1968 to 1975 and was the successor to the CII 10070. Its main competitor in Europe was the IBM 360/50, which, like the Iris 50, was a universal 32 bits mainframe suitable for both business and scientific applications.
The Mitra 15 is a minicomputer made by the French company CII under Plan Calcul, along with the Iris 50 and Iris 80 mainframe computers. It was marketed from 1971 to 1985 and could function in conjunction with large systems. CII manufactured a thousand Mitra 15 machines until 1975 in its Toulouse factory, then in Crolles in the suburbs of Grenoble. A total of 7,929 units were built, most of them for the French market, with a small number sold in Australia, Indonesia, and in other European countries.
