OS 400 – Complete History of the IBM OS/400

OS 400

Frank SoltisOn June 21, 1988, IBM introduced its new minicomputer and enterprise server platform AS/400 (later renamed to iSeries, System i and Power Systems), bundled with the operating system OS/400 (later renamed to i5/OS and IBM i). IBM’s Chief Scientist for AS/400 computers was Frank Gerald Soltis (see the nearby image), an US computer scientist, with pioneering contribution in the architecture of technology-independent machine interfaces (TIMI) and single-level storages.

Which are the key differences between OS/400 and other common operating systems?

1. The OS/400 is an object-based system with an integrated Database Management System DB2.

2. Single-level storage—a computer storage concept where the entire storage of a computer is thought of as a single two-dimensional plane of addresses. Pages may be in primary storage (RAM) or in secondary storage (disk); however, the current location of an address is unimportant to a process.

3. Technology Independent Machine Interface (TIMI)—a virtual instruction set, which allows the operating system and application programs to take advantage of advances in hardware and software without recompilation. All user-mode programs are stored as TIMI instructions, which means that it is not possible for them to use the instruction set of the underlying CPU, thus ensuring hardware independence.

  • Key features of IBM i:
  • Embedded into the OS DB2, 64-bit Relational Database Management System (RDBMS)
  • HTTP Server (powered by Apache)
  • IBM i NetServer (formerly AS/400 NetServer) is IBM i support for Windows Network Neighborhood
  • A rich set of security features and services that pertain to the goals of authentication, authorization, integrity, confidentiality, and auditing; Simple-to-deploy, Virus resistance object-based security model
  • Integration with SQL, .NET, DRDA/CLI, ODBC and JDBC; Support for MySQL database
  • Multiple file systems (Windows, UNIX, NFS)
  • Integrated Web application server, Java and J2EE Web services environment
  • Zend Server Community Edition providing PHP runtime environment
  • PowerVM technology providing Micro-Partitioning and shared processor pools
  • Automatic balancing of processor and memory resources
  • Transaction-based journaling leveraged by IBM iCluster and complementary high availability solutions
  • Highly resilient with built-in cluster architecture
  • Encryption of data on disk and backups
  • IBM Rational development tools, C, RPG, COBOL, C++, Java, EGL, PHP, CL; Supports open source applications built to Apache, MySQL, and PHP stack
  • Web-based systems management, IBM Systems Navigator, IBM Systems Director
  • logical partitioning (LPARs) with IBM i to support multiple virtual systems on a single hardware footprint
  • Integrated storage management, Hierarchal storage management for Solid State Drives
  • Support for IBM POWER processor-based systems and blades
  • Capacity on Demand (processor & memory)

The latest release of IBM i is 7.3, launched in April, 2016 (see below a table with OS/400 release history).

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OS/400 release history

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