79-649: SCL may refer to: Computing [ edit ] System Control Language, of the ICL VME operating system SC++L , the C++ standard library Software Collections in the CentOS Linux distribution System Command Language of the NOS/VE CDC Cyber operating system Structured Control Language , for programming PLCs Language [ edit ] Shina language , spoken by
158-466: A UNIX System V Release 3 based subsystem, called VME/X, adapted to run under VME and using the ASCII character encoding. ICL had originally announced a hosted Unix facility for VME in 1985, with availability and support for strategic applications to arrive within eighteen months. This facility, supporting SVR1 , was reportedly in "field trials" and was to be upgraded to SVR2 prior to a general release in
237-558: 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
316-412: A File Description. The Catalogue was probably the first example of what would later be called an entity-relationship database. Interrupts are handled by creating a new stack frame on the stack for the relevant process, handling the interrupt using this new environment, and then popping the stack to return to the interrupted process. Run-time exceptions, referred to as contingencies , are captured by
395-402: A VME process (or application-created sub-process) is more like a thread in other systems. However, processes running within a VM cannot run concurrently and thus resemble user threads found in other systems. A dedicated instruction is involved in the transfer of control between processes sharing the same VM. The allocation of resources to a virtual machine uses a stack model: when the stack
474-449: A fraction of the acquisition price and offer local users much greater control over their own systems given the IT policies and practices at that time. Terminals used for interacting with mainframe systems were gradually replaced by personal computers . Consequently, demand plummeted and new mainframe installations were restricted mainly to financial services and government. In the early 1990s, there
553-539: A level of sophistication not usually available with most server solutions. Modern mainframes, notably the IBM Z servers, offer two levels of virtualization : logical partitions ( LPARs , via the PR/SM facility) and virtual machines (via the z/VM operating system). Many mainframe customers run two machines: one in their primary data center and one in their backup data center —fully active, partially active, or on standby—in case there
632-403: A number of nodes , and each node contains its own order-code processor (CPU) and main memory. Virtual machines are typically located (at any one time) on one node, but have the capability to run on any node and to be relocated from one node to another. Discs and other peripherals are shared between nodes. Nodes are connected using a high-speed optical bus, which is used to provide applications with
711-434: A reference to the anticipated Year 2000 problem (Y2K). That trend started to turn around in the late 1990s as corporations found new uses for their existing mainframes and as the price of data networking collapsed in most parts of the world, encouraging trends toward more centralized computing. The growth of e-business also dramatically increased the number of back-end transactions processed by mainframe software as well as
790-561: A repository called the Catalogue. The file naming hierarchy is independent of the location of a file on a particular tape or disk volume. In days where there was more need for offline storage, this made it easy to keep track of files regardless of their location, and to move files between locations without renaming them. As well as files, the Catalogue keeps track of users and user groups, volumes, devices, network connections, and many other resources. Metadata for files can be held in an object called
869-540: A security Sha Tin to Central Link of the Hong Kong MTR transit system Studies in Canadian Literature , a literary journal See also [ edit ] Symptom Checklist 90 (SCL-90-R), psychometric instrument Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title SCL . If an internal link led you here, you may wish to change
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#1732848213154948-407: A single mainframe can replace higher-functioning hardware services available to conventional servers . While mainframes pioneered this capability, virtualization is now available on most families of computer systems, though not always to the same degree or level of sophistication. Mainframes can add or hot swap system capacity without disrupting system function, with specificity and granularity to
1027-558: A single module, for more efficient loading at run-time, and the Module Amender, which allows patching of the instructions in an OMF module to fix bugs, using assembly language syntax. The command language for VME is known as SCL (System Control Language). This is much more recognizably a typed high-level programming language than the job control or shell languages found in most other operating systems: it can be likened to scripting languages such as JavaScript , though its surface syntax
1106-487: A virtual shared memory. Memory segments that are marked as shared (public or global segments) are replicated to each node, with updates being broadcast over the inter-node network. Processes which use unshared memory segments (nodal or local) run in complete isolation from other nodes and processes. VME was originally written almost entirely in S3 , a specially-designed system programming language based on Algol 68R (however, VME/K
1185-421: Is S3 . This is a high level language based in many ways on Algol 68 , but with data types and low-level functions and operators aligned closely with the architecture of the 2900 series. An assembly language SFL ( S ystem F unction L anguage) is also available. This was used for the development of VME/K, whose designers were not confident that a high-level language could give adequate performance, and also for
1264-732: Is a catastrophe affecting the first building. Test, development, training, and production workload for applications and databases can run on a single machine, except for extremely large demands where the capacity of one machine might be limiting. Such a two-mainframe installation can support continuous business service, avoiding both planned and unplanned outages. In practice, many customers use multiple mainframes linked either by Parallel Sysplex and shared DASD (in IBM's case), or with shared, geographically dispersed storage provided by EMC or Hitachi. Mainframes are designed to handle very high volume input and output (I/O) and emphasize throughput computing. Since
1343-450: Is also spurring major mainframe investments to solve exceptionally difficult computing problems, e.g. providing unified, extremely high volume online transaction processing databases for 1 billion consumers across multiple industries (banking, insurance, credit reporting, government services, etc.) In late 2000, IBM introduced 64-bit z/Architecture , acquired numerous software companies such as Cognos and introduced those software products to
1422-634: Is being refreshed. In the late 1950s, mainframes had only a rudimentary interactive interface (the console) and used sets of punched cards , paper tape , or magnetic tape to transfer data and programs. They operated in batch mode to support back office functions such as payroll and customer billing, most of which were based on repeated tape-based sorting and merging operations followed by line printing to preprinted continuous stationery . When interactive user terminals were introduced, they were used almost exclusively for applications (e.g. airline booking ) rather than program development. However, in 1961
1501-757: Is dependent on its ability to scale, support mixed workloads, reduce labor costs, deliver uninterrupted service for critical business applications, and several other risk-adjusted cost factors. Mainframes also have execution integrity characteristics for fault tolerant computing. For example, z900, z990, System z9, and System z10 servers effectively execute result-oriented instructions twice, compare results, arbitrate between any differences (through instruction retry and failure isolation), then shift workloads "in flight" to functioning processors, including spares, without any impact to operating systems, applications, or users. This hardware-level feature, also found in HP's NonStop systems,
1580-445: Is derived from Algol 68 . SCL is designed to allow both line-at-a-time interactive use from a console or from a command file , and creation of executable scripts or programs (when the language is compiled into object module format in the same way as any other VME programming language). The declaration of a procedure within SCL also acts as the definition of a simple form or template allowing
1659-412: Is driven by its own local command file which is incorporated inline in the SCL between the delimiters "----" and "++++". The sub-commands INPUT and NEWMODULE identify the names of the input and output modules; SUPPRESS and RETAIN determine the external visibility of named procedures within the collected module; and LISTMODULE requests a report describing the output module. Note that "." is used to separate
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#17328482131541738-421: Is known as lock-stepping, because both processors take their "steps" (i.e. instructions) together. Not all applications absolutely need the assured integrity that these systems provide, but many do, such as financial transaction processing. IBM , with the IBM Z series, continues to be a major manufacturer in the mainframe market. In 2000, Hitachi co-developed the zSeries z900 with IBM to share expenses, and
1817-631: Is popped, all resources allocated at that stack level are released. Calls from an application to the operating system are therefore made by a call that retains the same process stack, but with a change in protection level; the resulting efficiency of system calls is one of the features that makes the architecture competitive. Communication between Virtual Machines is achieved by means of Events (named communication channels) and shared memory areas. The hardware architecture also provides semaphore instructions INCT (increment-and-test) and TDEC (test-and-decrement). Files and other persistent objects are recorded in
1896-514: Is similar to the "rings of protection" in Multics . The architecture allows 16 access levels, of which the outer 6 are reserved for user-level code. Orthogonally to the access levels, the operating system makes resources available to applications in the form of a Virtual Machine (VM). A VM can run multiple processes. In practice, a VM in VME is closer to the concept of a process in other operating systems, while
1975-443: Is structured as a set of layers, each layer having access to resources at different levels of abstraction. Virtual resources provided by one layer are constructed from the virtual resources offered by the layer below. Access to the resources of each layer is controlled through a set of Access Levels: in order for a process to use a resource at a particular access level, it must have an access key offering access to that level. The concept
2054-492: Is then deleted at the END of the block), S3_COMPILE (compiles a program written in S3: this command breaks the usual verb-noun convention), NEW_MESSAGE_TEXT_MODULE (creates a module containing parameterized error messages suitable for localization) and COMPILE_SCL, which compiles an SCL program into object code. The COLLECT command combines different object code modules into a single module, and
2133-657: Is unusually homogeneous, with most customers using the same core set of languages and tools. As a result, the tools are also very well integrated. Third-party tools have made relatively little impression. For many years the large majority of VME users wrote applications in COBOL , usually making use of the IDMS database and the TPMS transaction processing monitor. Other programming languages included Fortran , Pascal , ALGOL 68RS , Coral 66 and RPG2 , but these served minority interests. Later, in
2212-500: The 99 bottles of beer website. A more realistic example, where SCL is used to compile a program written in S3 , is shown below. This example is taken from the Columbia University Archive of implementations of Kermit . Commands illustrated in this fragment include WHENEVER (declares error handling policy), ASSIGN_LIBRARY (binds a local name for a file directory), DELETE_FILE (Makes a permanent file temporary, and it
2291-453: The CESG UK (Security) Evaluation Scheme, one of the predecessors to ITSEC and Common Criteria , and in doing so became the first mainstream operating system to be formally Certified. The Series 39 range introduced Nodal Architecture, a novel implementation of distributed shared memory that can be seen as a hybrid of a multiprocessor system and a cluster design. Each machine consists of
2370-649: The IDMS database system on account of its origins as a third-party product. SFL was originally called M acro A ssembler P rogramming L anguag E (MAPLE), but as the 2900 architecture was being positioned as consisting of high level language machines the name was changed at the request of ICL Marketing. It had been developed as a part of the toolkit for System D, which was subsequently cancelled. Related families of assemblers for other architectures (CALM-xx running under VME, PALM-xx developed in Pascal and running on various hosts) were developed for internal use. Neither S3 nor SFL
2449-541: The New Range system started on the merger of International Computers and Tabulators (ICT) and English Electric Computers in 1968. One of the fundamental decisions was that it would feature a new operating system. A number of different feasibility and design studies were carried out within ICL, the three most notable being: The chief architect of VME/B was Brian Warboys , who subsequently became professor of software engineering at
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2528-493: The Telum . Unisys produces code compatible mainframe systems that range from laptops to cabinet-sized mainframes that use homegrown CPUs as well as Xeon processors. Furthermore, there exists a market for software applications to manage the performance of mainframe implementations. In addition to IBM, significant market competitors include BMC and Precisely ; former competitors include Compuware and CA Technologies . Starting in
2607-517: The UK company International Computers Limited (ICL, now part of the Fujitsu group). Originally developed in the 1970s (as VME/B , later VME 2900 ) to drive ICL's then new 2900 Series mainframes, the operating system is now known as OpenVME incorporating a Unix subsystem, and runs on ICL Series 39 and Trimetra mainframe computers, as well as industry-standard x64 servers. The development program for
2686-643: The University of Manchester . A number of influences can be seen in its design, for example Multics and ICL's earlier George 3 operating system; however it was essentially designed from scratch. VME/B was viewed as primarily competing with the System/370 IBM mainframe as a commercial operating system, and adopted the EBCDIC character encoding . When New Range was first launched in October 1974, its operating system
2765-684: The 1960s, but they continue to evolve. Mainframe computers are often used as servers. The term mainframe was derived from the large cabinet, called a main frame , that housed the central processing unit and main memory of early computers. Later, the term mainframe was used to distinguish high-end commercial computers from less powerful machines. Modern mainframe design is characterized less by raw computational speed and more by: The high stability and reliability of mainframes enable these machines to run uninterrupted for very long periods of time, with mean time between failures (MTBF) measured in decades. Mainframes have high availability , one of
2844-504: The 1980s, many mainframes supported general purpose graphic display terminals, and terminal emulation, but not graphical user interfaces. This form of end-user computing became obsolete in the 1990s due to the advent of personal computers provided with GUIs . After 2000, modern mainframes partially or entirely phased out classic " green screen " and color display terminal access for end-users in favour of Web-style user interfaces. The infrastructure requirements were drastically reduced during
2923-595: The 2010s, cloud computing is now a less expensive, more scalable alternative. Several manufacturers and their successors produced mainframe computers from the 1950s until the early 21st century, with gradually decreasing numbers and a gradual transition to simulation on Intel chips rather than proprietary hardware. The US group of manufacturers was first known as " IBM and the Seven Dwarfs ": usually Burroughs , UNIVAC , NCR , Control Data , Honeywell , General Electric and RCA , although some lists varied. Later, with
3002-890: The 64-bit IBM Z CMOS servers have nothing physically in common with the older systems. Notable manufacturers outside the US were Siemens and Telefunken in Germany , ICL in the United Kingdom , Olivetti in Italy, and Fujitsu , Hitachi , Oki , and NEC in Japan . The Soviet Union and Warsaw Pact countries manufactured close copies of IBM mainframes during the Cold War ; the BESM series and Strela are examples of independently designed Soviet computers. Elwro in Poland
3081-663: The Department of Space of India Serial clock, a signal in I²C electronic messaging bus Short circuit level Skin conductance level, in medicine Sleep Convention Logic , a typo of asynchronous logic Structural composite lumber, an engineered wood Substation Configuration Language , for electrical substations Other [ edit ] Arturo Merino Benítez International Airport , Santiago, Chile by IATA airport code Seaboard Coast Line Railroad , by reporting mark Security characteristic line , plotting performance of
3160-542: The Japanese market. The amount of vendor investment in mainframe development varies with market share. Fujitsu and Hitachi both continue to use custom S/390-compatible processors, as well as other CPUs (including POWER and Xeon) for lower-end systems. Bull uses a mixture of Itanium and Xeon processors. NEC uses Xeon processors for its low-end ACOS-2 line, but develops the custom NOAH-6 processor for its high-end ACOS-4 series. IBM also develops custom processors in-house, such as
3239-550: The Object Program Error Handler (OPEH), which can produce a report (equivalent to a stack trace ), either interactively or written to a journal. Compiled object code is maintained in a format called OMF (Object Module Format), which is both the compiler output and the format used by the loader. Various compilers are available, as well as utilities, notably the Collector, which links the code in several OMF modules into
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3318-612: The Secure Systems arena. It had the advantage that as the last large-scale operating system ever designed, and one built from scratch, its underlying architecture encompassed many of the primitives needed to develop a Secure System, in particular the hardware assisted Access Control Registers (ACR) to limit to privileges that could be taken by any process (including Users). This led to the UK Government's Central Computing and Telecommunications Agency ( CCTA ) funding Project Spaceman in
3397-945: The Shina people in Gilgit-Baltistan, Pakistan Organizations [ edit ] SCL Group , a British data analysis and communication company Seattle City Light , public utility in Seattle, Washington, United States Southeastern Composers League Stanford Center on Longevity (SCL) Stanford University; see Stanford University centers and institutes National Senior Classical League Society of Chief Librarians , former name of Libraries Connected, British public library organisation Society of Construction Law IATA airport code for Arturo Merino Benítez International Airport (Santiago International Airport) Science and technology [ edit ] Sculptor (constellation) , astronomical abbreviation Semi-Conductor Laboratory of
3476-540: The VME/B base with a few selected features from VME/K grafted on. This provided the opportunity to drop some obsolescent features, which remained available to customers who needed them in the form of the "BONVME" option. The "2900" suffix was dropped at System Version 213 (SV213) when ICL launched Series 39 in 1985 as the successor to the original 2900 series, and the "Open" prefix was added after SV294. VME became capable of hosting applications written originally for Unix through
3555-524: The back-office engines behind the world's financial markets and much of global commerce". As of 2010 , while mainframe technology represented less than 3% of IBM's revenues, it "continue[d] to play an outsized role in Big Blue's results". IBM has continued to launch new generations of mainframes: the IBM z13 in 2015, the z14 in 2017, the z15 in 2019, and the z16 in 2022, the latter featuring among other things an "integrated on-chip AI accelerator" and
3634-409: The compilers used a module named ALICE [Assembly Language Internal Common Environment] and produced an early form of precompiled code (P-Code) termed ROSE, making compiled Object Module Format (OMF) libraries loadable on any machine in the range. . The primary language used for developing both the VME operating system itself and other system software such as compilers and transaction processing monitors
3713-592: The departure of General Electric and RCA, it was referred to as IBM and the BUNCH . IBM's dominance grew out of their 700/7000 series and, later, the development of the 360 series mainframes. The latter architecture has continued to evolve into their current zSeries mainframes which, along with the then Burroughs and Sperry (now Unisys ) MCP -based and OS1100 mainframes, are among the few mainframe architectures still extant that can trace their roots to this early period. While IBM's zSeries can still run 24-bit System/360 code,
3792-558: The early 1990s, many supercomputers were based on a mainframe architecture with supercomputing extensions. An example of such a system is the HITAC S-3800 , which was instruction-set compatible with IBM System/370 mainframes, and could run the Hitachi VOS3 operating system (a fork of IBM MVS ). The S-3800 therefore can be seen as being both simultaneously a supercomputer and also an IBM-compatible mainframe. In 2007, an amalgamation of
3871-748: The first academic, general-purpose timesharing system that supported software development, CTSS , was released at MIT on an IBM 709 , later 7090 and 7094. Typewriter and Teletype devices were common control consoles for system operators through the early 1970s, although ultimately supplanted by keyboard / display devices. By the early 1970s, many mainframes acquired interactive user terminals operating as timesharing computers, supporting hundreds of users simultaneously along with batch processing. Users gained access through keyboard/typewriter terminals and later character-mode text terminal CRT displays with integral keyboards, or finally from personal computers equipped with terminal emulation software. By
3950-559: The first time. IBM received the vast majority of mainframe revenue. During the 1980s, minicomputer -based systems grew more sophisticated and were able to displace the lower end of the mainframes. These computers, sometimes called departmental computers , were typified by the Digital Equipment Corporation VAX series. In 1991, AT&T Corporation briefly owned NCR. During the same period, companies found that servers based on microcomputer designs could be deployed at
4029-589: The form of environment variables ) can have a number of simple types such as strings, superstrings (sequences of strings), booleans, and integers, and are also used to contain references to system resources such as files and network connections. It is possible to "disassemble" an SCL program from OMF back into SCL source code using the READ_SCL (or RSCL) command. However the output is not always perfect, and will often include errors that would stop re-compilation without user intervention. A simple code example can be seen on
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#17328482131544108-752: The late 1950s, mainframe designs have included subsidiary hardware (called channels or peripheral processors ) which manage the I/O devices, leaving the CPU free to deal only with high-speed memory. It is common in mainframe shops to deal with massive databases and files. Gigabyte to terabyte -size record files are not unusual. Compared to a typical PC, mainframes commonly have hundreds to thousands of times as much data storage online, and can access it reasonably quickly. Other server families also offload I/O processing and emphasize throughput computing. Mainframe return on investment (ROI), like any other computing platform,
4187-726: The latest Hitachi AP10000 models are made by IBM. Unisys manufactures ClearPath Libra mainframes, based on earlier Burroughs MCP products and ClearPath Dorado mainframes based on Sperry Univac OS 1100 product lines. Hewlett Packard Enterprise sells its unique NonStop systems, which it acquired with Tandem Computers and which some analysts classify as mainframes. Groupe Bull 's GCOS , Stratus OpenVOS , Fujitsu (formerly Siemens) BS2000 , and Fujitsu- ICL VME mainframes are still available in Europe, and Fujitsu (formerly Amdahl) GS21 mainframes globally. NEC with ACOS and Hitachi with AP10000- VOS3 still maintain mainframe businesses in
4266-443: The link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=SCL&oldid=1165677015 " Category : Disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages ICL VME#SCL VME ( Virtual Machine Environment ) is a mainframe operating system developed by
4345-477: The mainframe. IBM's quarterly and annual reports in the 2000s usually reported increasing mainframe revenues and capacity shipments. However, IBM's mainframe hardware business has not been immune to the recent overall downturn in the server hardware market or to model cycle effects. For example, in the 4th quarter of 2009, IBM's System z hardware revenues decreased by 27% year over year. But MIPS (millions of instructions per second) shipments increased 4% per year over
4424-407: The mid 1980s for ICL Defence Technology Centre (DTC) to develop an enhanced security variant of VME. ICL launched this as a pair of complementary products, with the commercial release being called High Security Option (HSO), and the public sector release, including Government Furnished Encryption (GFE) technologies, being called Government Security Option (GSO). HSO and GSO were formally tested under
4503-524: The mid 1980s, compilers for C became available, both within and outside the Unix subsystem, largely to enable porting of software such as relational database systems. It is interesting that a PL/I subset compiler was written by the EEC, to assist in porting programs from IBM to ICL hardware. The compilers developed within ICL share a common architecture, and in some cases share components such as code-generators. Many of
4582-472: The mid-1990s, when CMOS mainframe designs replaced the older bipolar technology. IBM claimed that its newer mainframes reduced data center energy costs for power and cooling, and reduced physical space requirements compared to server farms . Modern mainframes can run multiple different instances of operating systems at the same time. This technique of virtual machines allows applications to run as if they were on physically distinct computers. In this role,
4661-433: The most secure, with vulnerabilities in the low single digits, as compared to thousands for Windows , UNIX , and Linux . Software upgrades usually require setting up the operating system or portions thereof, and are non disruptive only when using virtualizing facilities such as IBM z/OS and Parallel Sysplex , or Unisys XPCL, which support workload sharing so that one system can take over another's application while it
4740-431: The new Telum microprocessor . A supercomputer is a computer at the leading edge of data processing capability, with respect to calculation speed. Supercomputers are used for scientific and engineering problems ( high-performance computing ) which crunch numbers and data, while mainframes focus on transaction processing. The differences are: Mainframes and supercomputers cannot always be clearly distinguished; up until
4819-476: The parts of a hierarchic file name. A leading asterisk denotes a local name for a library, bound using the ASSIGN_LIBRARY command. The number in parentheses after a file name is a generation number. The operating system associates a generation number with every file, and requests for a file get the latest generation unless specified otherwise. Creating a new file will by default create the next generation and leave
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#17328482131544898-433: The past two years. Alsop had himself photographed in 2000, symbolically eating his own words ("death to the mainframe"). In 2012, NASA powered down its last mainframe, an IBM System z9. However, IBM's successor to the z9, the z10 , led a New York Times reporter to state four years earlier that "mainframe technology—hardware, software and services—remains a large and lucrative business for I.B.M., and mainframes are still
4977-477: The previous generation intact; this program however is deliberately choosing to create generation 101, to identify a public release. As a result of ICL's heavy involvement with delivery of computer services to the UK Public Sector, in particular those with special security requirements such as OPCON CCIS , it was an early entrant into the market for Secure Systems . VME formed a core of ICL's activities in
5056-628: The primary reasons for their longevity, since they are typically used in applications where downtime would be costly or catastrophic. The term reliability, availability and serviceability (RAS) is a defining characteristic of mainframe computers. Proper planning and implementation are required to realize these features. In addition, mainframes are more secure than other computer types: the NIST vulnerabilities database, US-CERT , rates traditional mainframes such as IBM Z (previously called z Systems, System z, and zSeries), Unisys Dorado, and Unisys Libra as among
5135-464: The procedure to be invoked from an interactive terminal, with fields validated according to the data types of the underlying procedure parameters or using the default procedure parameter values. The built-in command vocabulary uses a consistent naming convention with an imperative verb followed by a noun: for example DELETE_FILE or DISPLAY_LIBRARY_DETAILS. The command can be written in full, or in an abbreviated form that combines standard abbreviations for
5214-469: The reduced user base. Fujitsu intended to support VME on customer computers until 2020. In 2020 Fujitsu transferred 13 HM Revenue and Customs applications from their computers onto Fujitsu's virtual managed VME hosting platform. As of 2021, the Department for Work and Pensions completely replaced its VME based systems, following the completion of its award winning VME-R replacement programme. VME
5293-613: The size and throughput of databases. Batch processing, such as billing, became even more important (and larger) with the growth of e-business, and mainframes are particularly adept at large-scale batch computing. Another factor currently increasing mainframe use is the development of the Linux operating system, which arrived on IBM mainframe systems in 1999. Linux allows users to take advantage of open source software combined with mainframe hardware RAS . Rapid expansion and development in emerging markets , particularly People's Republic of China ,
5372-477: The summer of 1987. Limited availability was then announced to existing VME customers, with others being guided towards ICL's Clan range of Unix departmental systems. In October 1987, ICL made the SV221 release of VME available with support for running SVR2 as a VME Unix System guest. This implementation, described as an "unmarketed" product also known as VNS, informed the design of VME/X, a largely new implementation that
5451-429: The verb and noun: for example XF (X for DELETE, F for FILE) or DLBD (D for DISPLAY, LB for LIBRARY, D for DETAILS). SCL is block-structured, with begin/end blocks serving the dual and complementary roles of defining the lexical scope of variable declarations, and defining the points at which resources acquired from the operating system should be released. Variables in the language (which are accessible from applications in
5530-410: Was a rough consensus among industry analysts that the mainframe was a dying market as mainframe platforms were increasingly replaced by personal computer networks. InfoWorld ' s Stewart Alsop infamously predicted that the last mainframe would be unplugged in 1996; in 1993, he cited Cheryl Currid, a computer industry analyst as saying that the last mainframe "will stop working on December 31, 1999",
5609-594: Was also a project known as System D, which was an advanced, highly modular operating system designed for configuring and building customized near real-time applications. Although it was used to bid on a system for British Rail it was subsequently cancelled because of engineering resource constraints. ICL had sold a large system to the European Space Agency to process data from Meteosat at its operation centre in Darmstadt . A bespoke variant of VME/K, known as VME/ESA
5688-569: Was another Eastern Bloc manufacturer, producing the ODRA , R-32 and R-34 mainframes. Shrinking demand and tough competition started a shakeout in the market in the early 1970s—RCA sold out to UNIVAC and GE sold its business to Honeywell; between 1986 and 1990 Honeywell was bought out by Bull ; UNIVAC became a division of Sperry , which later merged with Burroughs to form Unisys Corporation in 1986. In 1984 estimated sales of desktop computers ($ 11.6 billion) exceeded mainframe computers ($ 11.4 billion) for
5767-453: Was developed on-site to meet the customer's requirements. Following a financial crisis in 1980, new management was brought into ICL: Christophor Laidlaw as Chairman, and Robb Wilmot as Managing Director. An early decision of the new management was to drop VME/K. Thus in July 1981, VME 2900 was launched. Although presented to the customer base as a merger of VME/B and VME/K, it was in reality
5846-443: Was developed with the aid of a software engineering repository system known as CADES , originally designed and managed by David Pearson (computer scientist) and built for the purpose using an underlying IDMS database. CADES is not merely a version control system for code modules: it manages all aspects of the software lifecycle from requirements capture, design methodology and specification through to field maintenance. CADES
5925-419: Was ever promoted as a commercial development tool for end-user applications, as neither were normally delivered as a standard part of the operating system, nor were they explicitly marketed as products in their own right. Both SFL and S3 were however available as options to user organisations and third parties who had a specific need for them. Mainframe computer A mainframe computer , informally called
6004-458: Was itself released in 1991 and recognised as XPG3 compliant, with XPG4 base 1 compliance following in 1992. In 2007 Fujitsu announced a VME version run as a hosted subsystem, called superNova , within Microsoft Windows , or SUSE or Red Hat Enterprise Linux on x86-64 hardware. In 2012 the VME user group, AXiS, announced that after almost 40 years it would be disbanding because of
6083-457: Was referred to as "System B". By the time it was first delivered it had become "VME/B". VME/K (originally known internally as "System T" for "Tiny") was developed independently (according to Campbell-Kelly, "on a whim of Ed Mack"), and was delivered later with the smaller mainframes such as the 2960. At the time VME/B was still plagued with performance and reliability problems, and the mainly American management team had misgivings about it. There
6162-584: Was used in VME module development to hold separate definitions of data structures (Modes), constants (Literals), procedural interfaces and the core algorithms. Multiple versions ('Lives') of each of these components could exist. The algorithms were written in System Development Language (SDL), which was then converted to S3 source by a pre-processor. Multiple versions of the same modules could be generated. The application development tools offered with VME fall into two categories: The toolset on VME
6241-474: Was written primarily in the SFL assembly language). Although a high-level language is used, the operating system is not designed to be independent of the underlying hardware architecture: on the contrary, the software and hardware architecture are closely integrated. From the early 1990s onwards, some entirely new VME subsystems were written partly or wholly in the C programming language . From its earliest days, VME
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