(Application System/400) The earlier generation and original name of IBM's iSeries and i5 families of midrange business computers. Introduced in 1988, the AS/400 evolved into the iSeries in 2000 and the i5 in 2004. When first introduced, the AS/400 was considered a "minicomputer."

Designed to Consolidate
An enhanced version of System/38, which included an integrated relational DBMS, the AS/400 was designed to consolidate System/38 and System/36 into one line. System/38 programs ran intact, but System/36 programs had to be recompiled.

The AS/400 served in a variety of networking configurations: as a host or intermediate node to other AS/400s, as a remote system to mainframe-controlled networks and as a network server to PCs.

POWER Based
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. IBM's POWER CPUs were used in subsequent AS/400 models. See iSeries and i5.