The AS400 and IBM i Knowledge Base for the IBM Power Era
Clear answers about AS400, IBM i, iSeries, System i, and modern IBM Power systems ... from legacy terminology to Power11 upgrade planning.
AS/400 Is Still How the World Searches for IBM i
AS/400 is the original IBM brand name, but AS400 is still how many IT professionals, executives, and administrators search for IBM i and IBM Power systems. The name changed over time. The business workloads did not disappear.
This site explains the full path from AS/400 to IBM i, from iSeries to IBM Power, and from legacy environments to modern Power11 infrastructure ... without jargon or sales pressure.
Knowledge Hubs
AS400 Learning Center
Foundational answers about the AS400 platform ... what it is, why it persists, and how it connects to modern IBM i and IBM Power systems.
IBM i Knowledge Base
IBM i is the operating system that runs on IBM Power Systems. This section covers how it works, how it's licensed, its roadmap, and what IBM i support looks like today.
IBM Power Hardware Center
IBM Power Systems are the hardware platform that runs IBM i workloads today. This section covers Power9, Power10, and Power11 hardware, model history, and how to evaluate your current environment.
Power 11 Upgrade Hub
IBM Power11 is the current generation of IBM Power Systems, announced July 8, 2025. This section covers Power11 specs, pricing, and upgrade paths from Power9 and Power10 environments.
AS400 Modernization Center
AS400 modernization does not always mean migration. This section covers green screen modernization, API enablement, cloud integration, and when it makes sense to stay on IBM i.
Tools and Resources
Quick-reference tools for IBM i and AS400 administrators and evaluators: terminology glossary, IBM i version timelines, CPW charts, end-of-support dates, and upgrade checklists.
Start Here
The most common AS400 and IBM i questions, answered.
Definitions for AS400, IBM i, RPG, CPW, DB2 for i, and all related terminology.
Browse the AS400 Glossary →Planning an AS/400 upgrade or Power11 migration? Explore BigTech Reseller's IBM section for IBM Power and IBM i reseller options.
Explore IBM Section →Still Running IBM i Workloads?
Learn how AS/400-era environments map to modern IBM Power systems and when a Power11 upgrade makes sense for your organization.
Recent Articles
AS400 History Timeline
This AS400 timeline tracks the platform from IBM's June 21, 1988 announcement through the 1995 RISC shift, the iSeries and System i rebrands, IBM i 7.5 and 7.6, and Power 5 through Power 11 milestone dates.
Read →AS400 Login Explained
AS400 login usually means signing in to an IBM i user profile, most often through a 5250 green-screen session, IBM i Access Client Solutions, or a modern web interface tied to the same IBM i system.
Read →AS400 Power Requirements
AS400 power requirements can mean either electrical requirements for the hardware or processing capacity requirements for the workload. The exact answer depends on whether you are discussing a legacy AS400 cabinet or a modern IBM Power replacement.
Read →AS400 vs iSeries vs System i
AS400, iSeries, and System i are not separate product families. They are successive IBM brand names for the same platform lineage that now continues as IBM i on IBM Power Systems hardware.
Read →Why Is It Still Called AS400?
AS400 remains the default name because it dominated the market for years, survived every IBM rebrand, and became the shorthand people still use for IBM i environments on IBM Power hardware.
Read →AS400 API Integration
Exposing existing RPG and COBOL program logic through APIs lets an AS400 or IBM i system connect to mobile apps, e-commerce platforms, and partner systems without rewriting decades of business logic. This is usually the highest-leverage modernization step an IBM i shop can take.
Read →Need IBM Power Reseller Options?
BigTech Reseller's IBM section helps buyers research IBM Power systems, AS400 upgrades, and IBM i solution providers.