The (Application System/400), introduced in 1988, is a renowned family of midrange computers designed for business applications. While the original hardware is no longer in production, its core architecture lives on in today’s IBM Power Systems running the IBM i operating system. Evolution and Rebranding
: Hardware consolidated into IBM Power Systems , with the operating system becoming IBM i . Core Architectural Features The (Application System/400), introduced in 1988, is a
: Everything on the system—files, programs, and devices—is treated as an object , which significantly enhances security and stability. Why It’s Still Relevant in 2026 The platform
: This layer separates applications from the underlying hardware, allowing companies to upgrade to new processors (like Power10) without modifying their software. and devices—is treated as an object
: This architecture treats all RAM and disk storage as one massive virtual address space, simplifying data management. Why It’s Still Relevant in 2026
The platform has undergone several name changes, often causing confusion for those outside the industry:
Over worldwide—including 16,000 banks—still rely on this platform for mission-critical workloads.