Midrange computers, or midrange systems, were a class of

computer A computer is a machine that can be programmed to Execution (computing), carry out sequences of arithmetic or logical operations (computation) automatically. Modern digital electronic computers can perform generic sets of operations known as C ...

systems that fell in between

mainframe computer 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, enterpris ...

s and

microcomputer A microcomputer is a small, relatively inexpensive computer having a central processing unit (CPU) made out of a microprocessor. The computer also includes memory and input/output (I/O) circuitry together mounted on a printed circuit board (PC ...

s. This class of machine emerged in the 1960s, with models from

Digital Equipment Corporation Digital Equipment Corporation (DEC ), using the trademark Digital, was a major American company in the computer industry from the 1960s to the 1990s. The company was co-founded by Ken Olsen and Harlan Anderson in 1957. Olsen was president unt ...

( PDP line),

Data General Data General Corporation was one of the first minicomputer firms of the late 1960s. Three of the four founders were former employees of Digital Equipment Corporation (DEC). Their first product, 1969's Data General Nova, was a 16-bit minicomputer ...

(

NOVA A nova (plural novae or novas) is a transient astronomical event that causes the sudden appearance of a bright, apparently "new" star (hence the name "nova", which is Latin for "new") that slowly fades over weeks or months. Causes of the dramati ...

Hewlett-Packard The Hewlett-Packard Company, commonly shortened to Hewlett-Packard ( ) or HP, was an American multinational information technology company headquartered in Palo Alto, California. HP developed and provided a wide variety of hardware components ...

(

HP3000 The HP 3000 series is a family of 16-bit computing, 16-bit and 32-bit computing, 32-bit minicomputers from Hewlett-Packard. It was designed to be the first minicomputer with full support for time-sharing in the hardware and the operating system, ...

) widely used in science and research as well as for business - and referred to as

minicomputer A minicomputer, or colloquially mini, is a class of smaller general purpose computers that developed in the mid-1960s and sold at a much lower price than mainframe and mid-size computers from IBM and its direct competitors. In a 1970 survey, ...

s. IBM favored the term "midrange computer" for their comparable, but more business-oriented systems. IBM midrange computers (1)

IBM Midrange Systems

System/3 The IBM System/3 was an IBM midrange computer introduced in 1969, and marketed until 1985. It was produced by IBM Rochester in Minnesota as a low-end business computer aimed at smaller organizations that still used IBM 1400 series computers or u ...

was the first IBM midrange system (1969) *

System/32 The IBM System/32 (IBM 5320) introduced in January 1975 was a midrange computer with built-in display screen, disk drives, printer, and database report software. It was used primarily by small to midsize businesses for accounting applications. R ...

(introduced in 1975) was a 16-bit single-user system also known as the IBM 5320. *

System/34 The IBM System/34 was an IBM midrange computer introduced in 1977. It was withdrawn from marketing in February 1985. It was a multi-user, multi-tasking successor to the single-user System/32. It included two processors, one based on the System/ ...

(1977) was intended to be a successor to both the 3 and the 32. *

System/38 The System/38 is a discontinued minicomputer and midrange computer manufactured and sold by IBM. The system was announced in 1978. The System/38 has 48-bit addressing, which was unique for the time, and a novel integrated database system. It w ...

(1979) was the first midrange system to have an integrated

relational database management system A relational database is a (most commonly digital) database based on the relational model of data, as proposed by E. F. Codd in 1970. A system used to maintain relational databases is a relational database management system (RDBMS). Many relatio ...

(DBMS). The S/38 had

48-bit In computer architecture, 48-bit integers can represent 281,474,976,710,656 (248 or 2.814749767×1014) discrete values. This allows an unsigned binary integer range of 0 through 281,474,976,710,655 (248 − 1) or a signed two's complement ra ...

addressing, and ran the CPF

operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also in ...

. *

System/36 The IBM System/36 (often abbreviated as S/36) was a midrange computer marketed by IBM from 1983 to 2000 - a multi-user, multi-tasking successor to the System/34. Like the System/34 and the older System/32, the System/36 was primarily progr ...

(1983) had two 16-bit processors with an operating system that supported multiprogramming. *

AS/400 The IBM AS/400 (Application System/400) is a family of midrange computers from IBM announced in June 1988 and released in August 1988. It was the successor to the System/36 and System/38 platforms, and ran the OS/400 operating system. Lower-cost ...

was introduced under that name in 1988, renamed eServer iSeries in 2000, and subsequently became the IBM System i in 2006. It runs the

OS/400 IBM i (the ''i'' standing for ''integrated'') is an operating system developed by IBM for IBM Power Systems. It was originally released in 1988 as OS/400, as the sole operating system of the IBM AS/400 line of systems. It was renamed to i5/OS ...

operating system. *

IBM Power Systems Power Systems is a family of server computers from IBM that are based on its Power processors. It was created in 2008 as a merger of the System p and System i product lines. History IBM had two distinct POWER- and PowerPC-based hardware li ...

were introduced in April 2008, a convergence of

IBM System i The IBM AS/400 (Application System/400) is a family of midrange computers from IBM announced in June 1988 and released in August 1988. It was the successor to the System/36 and System/38 platforms, and ran the OS/400 operating system. Lower-cost ...

and

IBM System p The IBM System p is a high-end line of RISC (Power)/UNIX-based servers. It was the successor of the RS/6000 line, and predecessor of the IBM Power Systems server series. History The previous RS/6000 line was originally a line of workstations and ...

Positioning

The main similarity of midrange computers and mainframes - they are both oriented for decimal-precision computing and high volume input and output (I/O), but most midrange computers have an (reduced and specially designed) internal architecture with limited compatibility to mainframes. The low-end mainframe can be more affordable and less powerful that a hi-end midrange system, but midrange system still was a "replacement solution" with another service process, different OS and internal architecture. The difference between similar-size Midrange and

Supermini The B-segment is the second smallest of the European segments for passenger cars between the A-segment and C-segment, and commonly described as "small cars". The B-segment is the largest segment in Europe by volume, accounting for 20 percent of ...

Minicomputer A minicomputer, or colloquially mini, is a class of smaller general purpose computers that developed in the mid-1960s and sold at a much lower price than mainframe and mid-size computers from IBM and its direct competitors. In a 1970 survey, ...

- is a computing purposes: Super/mini oriented for float-point scientific computing, midrange - for decimal business-oriented computing, but without clear distinction border between classes. Earliest midrange computers was a single-user business calculation machines; the virtualization, typical feature of mainframes since 1972 (partially from 1965), was ported to midrange systems only in 1977; the multi-user support was added to midranges in 1976 instead of 1972 for mainframes (but that's still a significantly earlier that a limited release of x86 virtualization (1985/87) or multi-user support (1983)). Latest midrange systems are primarily mid-class multi-user local network servers that can handle the large-scale processing of many

business applications Business software (or a business application) is any software or set of computer programs used by business users to perform various business functions. These business applications are used to increase productivity, measure productivity, and perf ...

. Although not as powerful and reliably as full-size

mainframe computers 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, enterpris ...

, they are less costly to buy, operate, and maintain than mainframe systems and thus meet the computing needs of many organizations. Midrange systems was relatively popular as powerful network servers to help manage large Internet Web sites, but more oriented for corporate intranets and extranets, and other networks. Today, midrange systems include servers used in industrial process-control and manufacturing plants and play major roles in computer-aided manufacturing (CAM). They can also take the form of powerful technical workstations for computer-aided design (CAD) and other computation and graphics-intensive applications. Midrange system are also used as front-end servers to assist mainframe computers in telecommunications processing and network management. Since the end of 1980s, when the

client–server model The client–server model is a distributed application structure that partitions tasks or workloads between the providers of a resource or service, called servers, and service requesters, called clients. Often clients and servers communicate over ...

of computing became predominant, computers of the comparable class are instead usually known as '' workgroup servers''"now referred to as small or midsize servers." and ''online transaction processing servers'' to recognize that they usually "serve" end users at their "client" computers. For the 1990-2000's, in some non-critical cases both lines also was replaced by ''web servers'', oriented for working with global network, but with less security background, and mainly based using General purpose architecture (currently x86 or ARM).

References

{{DEFAULTSORT:Midrange Computer *Midrange

IBM Midrange Systems

Positioning

See also

References