OS 400 By Yuuta12408 1979 System/38 1988 AS/400 (Advanced System/400) 1988 OS/400 V1R1 1990 OS/400 V2R1 1992 OS/400 V3R1 1996 OS/400 V4R1 2004 i5/OS V5R1 2008 IBM i 6.1 2010 IBM i 7.1 2014 IBM i 7.2 2016 IBM i 7.3 2019 IBM i 7.4