IBM AS/400 Superseded
IBM AS/400
KindMachine
Introduced1988
Discontinued1997
StatusSuperseded
ManufacturerIBM
ClassMidrange
PlatformIMPI → PowerPC
Sourcebitsavers.org ↗
The midrange box businesses ran on and never thought about — integrated database, single-level store, object security. Renamed iSeries, then IBM i; the line still ships.
1960198020002020
The AS/400 (June 1988) replaced the System/36/38 midrange — integrated DB2 database, single-level store (memory+disk as one address space), object-level security, and legendary backward compatibility.
Businesses ran it without thinking about it — 'the box in the closet' — through renames (iSeries 2000, System i 2006, IBM i 2008) and architecture migrations (CISC → PowerPC, 1995). The platform still ships today as IBM i on Power.