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Related to AS/400: I Series


An IBM minicomputer for small business and departmental users, released in 1988 and still in production in October 1998.

Features include a menu-driven interface, multi-user support, terminals that are (in the grand IBM tradition) incompatible with anything else including the IBM 3270 series, and an extensive library-based operating system.

The machine survives because its API layer allows the operating system and application programs to take advantage of advances in hardware without recompilation and which means that a complete system that costs $9000 runs the exact same operating system and software as a $2 million system. There is a 64-bit RISC processor operating system implementation.

Programming languages include RPG, assembly language, C, COBOL, SQL, BASIC, and REXX. Several CASE tools are available: Synon, AS/SET, Lansa.


(Application System/400) The first generation of IBM's midrange business computers, which evolved into the Power Systems family. Introduced in 1988, the AS/400 served as a host or intermediate node to other AS/400s, as a remote system to mainframes and as a network server to PCs. Today, the Power Systems successors to the AS/400 are IBM's non-mainframe computer family. See Power Systems.

Designed to Consolidate
The AS/400's unique feature was its OS/400 environment, which included an integrated relational database, a feature of the earlier System/38. The AS/400 ran System/38 applications intact, but System/36 programs had to be recompiled. See OS/400, System/36 and System/38.

In 1994, IBM introduced the AS/400 Advanced System/36, a PowerPC-based version of the AS/400 that natively ran the System/36 SSP operating system and its applications. Starting that year, IBM's POWER CPUs were used in AS/400 models. See POWER CPU.

An Early AS/400
The AS/400 has been used in businesses of all sizes, and thousands of applications were written for it. (Image courtesy of IBM.)