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.
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.
Transaction Processing Facility (TPF) is an IBM real-time operating system for mainframe computers descended from the IBM System/360 family, including zSeries and System z9.
z/OS is a 64-bit operating system for IBM z/Architecture mainframes, introduced by IBM in October 2000. It derives from and is the successor to OS/390, which in turn followed a string of MVS versions. Like OS/390, z/OS combines a number of formerly separate, related products, some of which are still optional. z/OS has the attributes of modern operating systems, but also retains much of the older functionality originated in the 1960s and still in regular use—z/OS is designed for backward compatibility.
OS/390 is an IBM operating system for the System/390 IBM mainframe computers.
Hercules is a computer emulator allowing software written for IBM mainframe computers and for plug compatible mainframes to run on other types of computer hardware, notably on low-cost personal computers. Development started in 1999 by Roger Bowler, a mainframe systems programmer.
Db2 is a family of data management products, including database servers, developed by IBM. They initially supported the relational model, but were extended to support object–relational features and non-relational structures like JSON and XML. The brand name was originally styled as DB/2, then DB2 until 2017 and finally changed to its present form.
Amdahl Corporation was an information technology company which specialized in IBM mainframe-compatible computer products, some of which were regarded as supercomputers competing with those from Cray Research. Founded in 1970 by Gene Amdahl, a former IBM computer engineer best known as chief architect of System/360, it has been a wholly owned subsidiary of Fujitsu since 1997. The company is located in Sunnyvale, California.
The Integrated Facility for Linux (IFL) is an IBM mainframe and Power Systems processor dedicated to running the Linux operating system. On IBM Z and IBM LinuxONE machines, IFLs can be used with or without hypervisors such as z/VM and KVM. IFLs are one of three most common types of "specialty" IBM mainframe processors that give software vendors more granular control over software licensing and maintenance costs.. Microcode restricts IFLs to Linux workload by omitting some processor instructions not used by the Linux kernel, but the underlying processors are physically identical to general purpose processors (CPs). When IBM adds features and performance improvements to its mainframes' general purpose main processors, those features and improvements nearly always apply equally to IFLs. In fact, in recent IBM Z machines IFLs support simultaneous multithreading, a feature not available for general purpose processors.
A hypervisor is similar to an emulator; it is computer software, firmware or hardware that creates and runs virtual machines. A computer on which a hypervisor runs one or more virtual machines is called a host machine, and each virtual machine is called a guest machine. The hypervisor presents the guest operating systems with a virtual operating platform and manages the execution of the guest operating systems. Multiple instances of a variety of operating systems may share the virtualized hardware resources: for example, Linux, Windows, and macOS instances can all run on a single physical x86 machine. This contrasts with operating-system–level virtualization, where all instances must share a single kernel, though the guest operating systems can differ in user space, such as different Linux distributions with the same kernel.
IBM System z9 is a line of IBM mainframe computers. The first models were available on September 16, 2005. The System z9 also marks the end of the previously used eServer zSeries naming convention. It was also the last mainframe computer that NASA ever used.
SUSE Linux Enterprise is a Linux-based operating system developed by SUSE. It is available in two editions, suffixed with Server (SLES) for servers and mainframes, and Desktop (SLED) for workstations and desktop computers. Its major versions are released at an interval of 3–4 years, while minor versions are released about every 12 months. SUSE Linux Enterprise products receive more intense testing than the upstream openSUSE community product, with the intention that only mature, stable versions of the included components will make it through to the released enterprise product.
SUSE is a German-based multinational open-source software company that develops and sells Linux products to business customers. Founded in 1992, it was the first company to market Linux for enterprise. It is the developer of SUSE Linux Enterprise and the primary sponsor of the community-supported openSUSE Project, which develops the openSUSE Linux distribution. While the openSUSE "Tumbleweed" variation is an upstream distribution for both the "Leap" variation and SUSE Linux Enterprise distribution, its branded "Leap" variation is part of a direct upgrade path to the enterprise version, which effectively makes openSUSE Leap a non-commercial version of its enterprise product.
IBM S/390 Multiprise was a short-living series of small, compact entry-level mainframes.
Since the rise of the personal computer in the 1980s, IBM and other vendors have created PC-based IBM-compatible mainframes which are compatible with the larger IBM mainframe computers. For a period of time PC-based mainframe-compatible systems had a lower price and did not require as much electricity or floor space. However, they sacrificed performance and were not as dependable as mainframe-class hardware. These products have been popular with mainframe developers, in education and training settings, for very small companies with non-critical processing, and in certain disaster relief roles.
IBM Z is a family name used by IBM for all of its z/Architecture mainframe computers from the z900 on.
Basic Assembly Language (BAL) is the commonly used term for a low-level programming language used on IBM System/360 and successor mainframes. Originally, "Basic Assembly Language" applied only to an extremely restricted dialect designed to run under control of IBM Basic Programming Support (BPS/360) on systems with only 8 KB of main memory, and only a card reader, a card punch, and a printer for input/output — thus the word "Basic". However, the full name and the initialism "BAL" almost immediately attached themselves in popular use to all assembly-language dialects on the System/360 and its descendants. BAL for BPS/360 was introduced with the System/360 in 1964.
Linux on IBM Z is the collective term for the Linux operating system compiled to run on IBM mainframes, especially IBM Z and IBM LinuxONE servers. Similar terms which imply the same meaning are Linux on zEnterprise, Linux on zSeries, Linux/390, Linux/390x, etc. The three Linux distributions certified for usage on the IBM Z hardware platform are Red Hat Enterprise Linux, SUSE Linux Enterprise, and Ubuntu.
The IBM System/390 is the discontinued fifth generation of the System/360 instruction set architecture. The first ESA/390 computer was the Enterprise System/9000 (ES/9000) family, which were introduced in 1990. These were followed by the 9672 CMOS System/390 mainframe family in the mid-1990s. These systems followed the IBM 3090, with over a decade of follow-ons. The ESA/390 was succeeded by the 64-bit z/Architecture in 2000.
