AS400 Learning Center

AS400 History Timeline

The AS400 timeline starts with IBM's June 21, 1988 launch, runs through the 1995 RISC transition and the iSeries and System i rebrands, and continues today as IBM i on IBM Power hardware.

The AS400 story is not a short-lived hardware product history. It is a four-decade platform timeline that starts with the AS/400 launch in 1988 and continues through multiple IBM renames to the current IBM i and IBM Power era. The names changed. The platform lineage remained intact.

Vertical Platform Timeline

  1. 1988 June 21 launch

    AS/400 debuts as one platform replacing two IBM mid-range families

    IBM launches the AS/400 as the successor to both System/36 and System/38, combining hardware, OS/400, and an integrated relational database into one managed business platform.

    Often missed Most timeline pages mention the launch date but skip the fact that IBM was collapsing two different customer bases and operating models into one system.

  2. 1988 Architecture decision

    Machine independence is built in from day one

    The platform starts with object-based design and a technology-independent machine interface, which becomes the foundation for keeping old applications alive across later processor changes.

    Often missed This architectural choice is why the platform could survive future hardware shifts without forcing a mass application rewrite.

  3. 1995 RISC transition

    IBM moves AS/400 from CISC to RISC hardware

    IBM shifts the platform to PowerPC-AS RISC hardware while preserving continuity for customer workloads, modernizing the box without resetting the software base.

    Often missed The overlooked part is not just the processor change ... it is the compatibility model that let old code survive the move.

  4. 2000 October rename

    AS/400 becomes eServer iSeries

    IBM rebrands the platform for the e-business era, but the change is largely commercial language and positioning rather than a disruptive migration event for existing shops.

    Often missed For many organizations this was a naming change layered on top of the same workload lineage, not a fresh platform decision.

  5. 2004 Power 5 refresh

    iSeries i5 and i5/OS point toward deeper convergence

    IBM refreshes the line onto POWER5 processors and renames the operating system i5/OS, pushing the platform closer to the hardware convergence that later defines the Power era.

    Often missed This step is often skipped, even though it is one of the clearest bridges between the older AS/400 world and the later IBM Power model.

  6. 2006 System family unification

    iSeries becomes System i

    IBM folds the platform into its broader System-family branding, aligning the product more visibly with shared server-family strategy while keeping compatibility intact.

    Often missed The interesting milestone is the broader IBM server-family consolidation, not just the shorter product name.

  7. 2008 Identity split

    IBM i becomes the OS and Power Systems becomes the hardware

    This is the modern naming model: IBM i is the operating system, IBM Power Systems is the hardware family, and AS400 remains the market shorthand many people still search with.

    Often missed Many sites say AS400 became IBM i and stop there, but the more accurate story is that IBM separated the OS identity from the server-hardware brand.

  8. 2022 Current OS era

    IBM i 7.5 confirms continued platform investment

    A major IBM i release in 2022 shows the platform is still under active operating-system development, not merely being kept alive for maintenance-only customers.

    Often missed There is a real difference between workloads still running and a platform still receiving major OS engineering investment.

  9. 2025 Current hardware era

    Power 11 becomes the next planning milestone

    IBM announces Power11 on July 8, 2025, extending the hardware line that now carries modern IBM i workloads descended directly from original AS/400 environments.

    Often missed The useful ending point for an AS400 timeline is not the last rename ... it is the current Power-generation upgrade decision in front of real IBM i shops.

Why This Timeline Is More Useful Than a Rename List

Most AS400 histories stop at brand changes. That is not what made this platform durable. The real story is the chain of architectural and product decisions that preserved application continuity while IBM kept changing processor families, hardware names, and commercial positioning.

If you need the hardware side of the story next, continue to AS400 Model History, iSeries Model History, and IBM Power Systems Overview.

Frequently Asked Questions

When did AS400 become iSeries?
IBM replaced the AS/400 brand with iSeries in 2000.
Did AS400 become IBM i or IBM Power?
Both terms matter. IBM i is the current operating system name, while IBM Power Systems is the current hardware family that runs IBM i.
Is AS400 still being made?
The AS400 brand itself is not used for new hardware, but the platform lineage continues today as IBM i on IBM Power Systems.