History of OS/400

The operating system, like the hardware of the midrange family, has changed significantly since its release on August 26, 1988 as OS/400 Release 1. The latest version is known as i5/OS V5R4 and was released to general availability on February 11, 2006.

Predecessors

• Wikipedia:System/3
• Wikipedia:System/32
• Wikipedia:System/34
• Wikipedia:System/36

Release life cycle

• Release life cycle

Current releases

• IBM i5/OS & OS/400 release support

Previous release support

Values for TGTRLS parameter

Installed release	*CURRENT	*PRV	Other valid values
V5R3	V5R3M0	V5R2M0	V5R1M0 V5R2M0 V5R3M0
V5R2	V5R2M0	V5R1M0	V5R1M0 V5R2M0
V5R1	V5R1	V4R5	V4R4
V4R5	V4R5M0	V4R4M0	V3R2M0 V4R2M0 V4R3M0 V4R4M0 V4R5M0
V4R4	V4R4	V4R3	V4R2 V3R2
V4R3	V4R3	V4R2	V4R1 V3R7 V3R2
V4R2	V4R2M0	V4R1M0	V3R2M0 V3R7M0 V4R1M0 V4R1M4 V4R2M0

• from PDF

iSeries - AS/400 RISC Model to OS Level Mapping

• http://www-304.ibm.com/jct01004c/systems/support/i/planning/upgrade/osmapping.html