IBM iSeries/AS400 Systems Timeline

For over 50 years, IBM i has undergone continuous evolution, adapting to new technologies and business demands. From its origins in the 1960s as System/3 to the modern IBM Power Systems running IBM i 7.5, this platform has rebranded and enhanced its midrange computing systems, introducing groundbreaking features that have helped organizations optimize their operations. In this article, we will provide a comprehensive overview of the milestones that have shaped the IBM i journey, including its history, key technological advancements, and what the future holds for this enduring platform.

IBM i System Milestones at a Glance

IBM i has evolved over the last 30+ years, changing the name of its operating systems (OS) and servers along the way. Here’s a visual overview of the various terms that IBM i has been referred to since the 1960s.

Now let’s take a look at each of these versions comprehensively.

AS400/IBM i Roadmap: From the System/3 of the Past to The IBM i of the Present

System/3 (1969)

System/3 was the first mid-range computer that IBM introduced as a part of its “midrange systems” line in 1969. Originally targeting small companies relying on IBM 1400 series computers or unit record equipment, they were used for business operations like billing, inventory control, and payroll.

It used the System/3 (also called OS/3) operating system. This platform introduced RPG II programming language, laying the foundation for IBM’s midrange line, AS/400, iSeries, System i, and IBM Power Systems. Apart from RPG II, it supported Assembler, COBOL, and Fortran IV.

However, due to limitations like process pausing inability, complex error code display, and computing and keypunching restrictions, IBM stopped leasing these systems from 1985 onwards.

IBM System/3 Model 10 (Source: Wikipedia)

System/32 (1975)

IBM System/32 (or IBM 5320) was the successor of the System/3 line of computers introduced in January 1975. This 16-bit, single-user, midrange computer platform was the first system to have hardware and application software, comprising built-in database report software, disk drives, display screens, and printers.

With an appearance like a large office desk and a small 6-line by 40-character display, the system mainly operated using a System Control Program (SCP) OS, 16-bit Control Storage Processor (CSP), and RPG II. It also came with 16/24/32 kilobyte memory storage, 8/16 kilobyte control storage, 5/9/13 megabyte hard drive, and an eight-inch floppy drive. Built for small to medium-sized businesses, these systems were mainly used for accounting operations.

These systems were withdrawn from the market on October 17, 1984, paving the way for a new line of systems.

IBM System/32 (Source: Wikipedia)

System/34 (1977)

Introduced in April 1977, IBM System/34 was a multi-user, multi-tasking version of its predecessor built for large organizations to simplify complex operations. Announced to lower costs related to distributive data processing, these systems used eight workstations simultaneously to deliver real-time access to current data.

These systems had hardware comprising two processors (CSP and MSP or Main Storage Processor), 48 to 256 kilobyte RAM, 48 to 256 megabyte hard drive storage, and 2560 byte disk space. The unique features of these systems included memory paging, which could swap segments of/entire programs to make space for other programs to run, and an offline storage mechanism that helped load and eject 8-inch floppies non-sequentially.

These systems relied on the System Support Program (SSP) operating system and Operational Control Language (OCL). The initial versions supported Basic Assembler and RPG II but the later versions ensured compatibility with BASIC, COBOL, and FORTRAN.

Taken off from sale in February 1985, IBM devised to enhance this version into a more robust and sustainable one.

IBM System/34 (Source: Wikipedia)

System/38 (1979)

Announced on October 24, 1978, and commercially made available in August 1979, the System/38 was a 48-bit, multi-user minicomputer with an integrated relational database known as Db2. It was intended for large organizations’ general business operations.

These systems had hardware consisting of a CPU, 512/ 768/1024/1280/1536 kilobyte main storage, a system console, a keyboard, a 5250 display screen, and a diskette magazine drive. In terms of software, System/38 relied on a Control Program Facility (CPF) OS, a machine interface architecture, and micro-codes. The fascinating detail about these systems is their built-in security to control access to objects and files on a user-to-user basis.

However, System/38 turned too expensive for many business operations, which led IBM to release a low-end business computer version called System/36. In addition, failing to replace systems in the market that managed numerous terminals, these systems were discontinued in 1988.

IBM System/38 (Source: Wikipedia)

System/36 (1983)

The low-cost version of IBM System/38 intended for small businesses and general operations was System/36. Introduced on 16 May 1983 and shipped in 1984, the SSP OS-based platform had a similar configuration as System/38.

However, its hardware configurations included 16-bit CSP and MSP, a four hexadecimal LED-based front panel display, 128 kilobytes to 7 megabytes RAM, 30 megabytes to 1478 megabytes disk space storage with an “extra cylinder” feature. 

It was discontinued in 1988 when IBM consolidated System/36 and System/38 into AS/400.

IBM System/36 (Source: Wikipedia)

AS/400 (1988)

Succeeding System/36 and System/38, IBM Application System/400 (commonly known as the AS/400) was announced in June 1988 and launched a month later. As one of the most successful models, IBM shipped almost  500,000 AS/400 systems by the end of 1997. The goal was to provide small and medium-sized businesses as well as government organizations with an accessible, powerful platform that facilitated networked computing and paved the way for paperless operations.

The earlier versions of AS/400 comprised a 48-bit CISC originally designed for the System/38. The later versions relied on a 64-bit PowerPC-derived CPU.

Software-wise, these systems had an OS/400 operating system, object-based design, single-level storage, relational database, menu-driven interface, 5250 terminal, and multi-user support.

The AS/400 went through re-branding several times over the years becoming System i, iSeries, and Power Systems that we know today.

IBM AS/400 (Source: Wikipedia)

iSeries (2000)

IBM introduced a range of computer servers called eServer in 2000. As a part of this drive, IBM combined its diverse server brands into one. This rebranding aimed to provide a cohesive server solution for businesses, integrating various functionalities to support diverse workloads.

IBM AS/400 was transitioned to IBM eServer iSeries, where the ‘i’ denoted integrated. The iSeries used the OS/400 operating system to support existing AS/400 applications. The AS400 to iSeries transition mainly comprised system capability enhancement to run emerging e-business applications.

In 2004, IBM introduced the eServer i5 that featured the POWER5 processors and rebranded OS/400 as i5/OS. The eServer iSeries line was discontinued in 2006, transitioning to the IBM System i brand as part of IBM’s broader rebranding strategy.

System i/IBM i V5R4 (2006)

In January 2006, IBM released the System i (also known as the IBM i V5R4) for small and medium-sized businesses. The goal was to provide organizations with an integrated IT system with a simple infrastructure, enhanced business resiliency, and robust security.

The System i used IBM PowerPC-AS architecture processors, DDR2 memory, 193 terabyte disk space storage, and new I/O capabilities like RAID6 and iSCSI adapters. On the software side, it used the upgraded i5/OS operating system, integrated middleware, and virtual tape. In addition, it supported programming languages like RPG, COBOL, and Java.

IBM transitioned the System i version to IBM Power Systems and ceased marketing it in February 2008.

IBM Power System/IBM i 6.1 (2008)

In January 2008, IBM merged the System i and System p platforms into a single platform called IBM Power Systems (to be called IBM Power since 2021). IBM also introduced a new version of the i5/OS operating system called IBM i 6.1 in the same year. Later in the same year, i5/OS was renamed to IBM i, accompanied by notations like 6.1 to denote OS release levels.

These systems comprised IBM POWER5, POWER5+, and POWER6 hardware and supported IBM i, AIX (UNIX), and Linux operating systems.

The advancements of these systems were brought in by its operating system 6.1. The key innovations in IBM i 6.1 included:

• Security Enhancements: IBM i 6.1 expanded its base security options with robust network intrusion detection capabilities. It is also integrated with Backup Recovery and Media Services (BRMS) to support data encryption during disk and tape backups.
• Backup, Recovery, and High Availability: IBM i 6.1 introduced enhanced save-while-active options that improved journaling and clustering for flexible save and restore operations. Additionally, it launched the IBM High Availability Solutions Manager (HASM), later rebranded as PowerHA for i, for advanced high availability configurations.
• Virtualization and Hardware Integration: IBM i 6.1 supported virtualization of storage using virtual I/O, allowing hosting by another IBM i or Virtual I/O Server partition. It also enabled operation on POWER6 BladeCenter servers and strengthened integration with System x and BladeCenter hardware.
• Database Enhancements: IBM Db2 for i received functional and performance improvements, along with cost-effective options for Db2 Web Query for i to simplify reporting and analytics.
• Java and Application Development: IBM i 6.1 improved Java performance with the introduction of 64-bit JVMs and updated JDK levels. It expanded development tools with Rational Development for i (RDi) and Rational Developer for i for SOA Construction. Further, it enhanced CL, C++, RPG, and COBOL support for web services enablement and multithreading.
• Web Enablement: This version simplified web application deployment with the Integrated Web Application Server for i, catering to basic Java requirements. It also introduced the Integrated Web Services for i server for foundational web services capabilities.
• System Management and Performance: It introduced the IBM Systems Director Navigator for i, a web-based management interface featuring graphical performance analysis. It also integrated IBM Systems Director 6.1 for multiplatform management across Linux, AIX, Windows, and more.

IBM eventually withdrew this version from the market in 2013 and stopped supporting it in September 2015.

IBM Power System/IBM i 7.1 (2010)

Released in early 2010, IBM i 7.1 was designed to cater to enterprise clients and developers. IBM aimed to deliver enhanced database functionality, graphical application development, and virtualization.

It supported POWER5, POWER6, and POWER7 processors. Later, it ensured compatibility with POWER7+ processors as well as advanced systems like Flex System p260 and p460 compute nodes.

This version provided better resource utilization for logical partitions, expanded hardware support, and improved virtualization features. In addition, it introduced new capabilities, including enriched storage mirroring algorithms, simplified deployment of updates through Technology Refresh mechanisms, and thin provisioning of shared storage pools.

IBM i 7.1 remained on the market until April 30, 2015, and received support till April 2018.

IBM Power System/IBM i 7.2 (2014)

IBM i 7.2 was released on May 2, 2014, to address the growing needs of enterprises for robust, secure, and scalable computing environments. It supported processors from POWER6 to POWER8 models. However, it ceased to support POWER5 and earlier processors.

Software-wise, it upgraded DB2 for i and Backup Recovery Media Services (BRMS). It also introduced enhanced security with Row and Column Access Control (RCAC), updated support for Java, and enhanced IBM HTTP Server for i with Apache 2.4.12. The key innovations in IBM i 7.2 included:

• Virtualization: Improved iVirtualization capabilities with support for up to 32 virtual disks via VSCSI and better resource management.
• Database Enhancements: Advanced features in Db2, such as RCAC, and better indexing for query optimization.
• Application Development: Free-form RPG support and compatibility with modern programming frameworks.
• System Management: Enhanced IBM Navigator for i, including Advanced Job Scheduler integrations.
• Backup and Recovery: More advanced BRMS features for seamless system restoration.

IBM withdrew its support for this version in April 2021.

IBM Power System/IBM i 7.3 (2016)

IBM i 7.3, released in April 2016, aimed to enhance enterprise computing with enhancements focused on data-centric applications, analytics, and improved system security. This new version brought in new features and capabilities, including:

• Enhanced Database Capabilities: IBM i 7.3 introduced new SQL-based services, advanced query optimization techniques, and temporal tables. Additionally, it also ensured JSON integration support.
• Advanced Security: This version improved system security with Authority Collection and enhanced encryption capabilities.
• Analytics and Reporting: It expanded in-database analytics support through SQL enhancements, enabled IBM i Navigator integration, and introduced built-in analytics and reporting tools.
• Development and Modernization: It introduced new REST APIs, started supporting open-source tools and programming languages (like Python, PHP, and Ruby), and enabled modern DevOps workflows through Git and other tools.
• Improved Systems Management: It brought in refined system management interfaces and enhanced cloud integration.
• Performance Enhancements: This version optimized workload management. It also improved POWER8 and POWER9 hardware support.

IBM officially stopped marketing this version on April 28, 2023, and ceased its support on September 30, 2023.

IBM Power System/IBM i 7.4 (2019)

IBM i 7.4, released in June 2019, introduced groundbreaking features aimed at enhancing availability, modernization, and security. This version preserved most of the capabilities and features of its predecessor, however, some of the news additions include:

• Db2 Mirror for i enabling two systems to access the same database concurrently
• Authority Collection enhancements for monitoring object-level authorities
• Support for Transport Layer Security (TLS) 1.3 for improved encryption
• Digital Certificate Manager (DCM) enhancements with new APIs for automating certificate tasks
• Extended SQL capabilities for JSON support
• INCLUDE statement for reusing common code in SQL procedures, functions, and triggers
• Improved external procedures and functions for better ILE service program interoperability
• Secured QFileSvr.400 connections with TLS support
• Enhanced configuration options for data protection during file transfers
• Support for Non-Volatile Memory Express (NVMe) for faster and more efficient storage
• Added flexibility to the SAVE menu options (21, 22, 23) by enabling users to control the start of the controlling subsystem after backups

IBM still supports the 7.4 version and will likely do so in the future.

IBM Power System/IBM i 7.5 (2022)

IBM i 7.5, released on May 10, 2022, is the latest operating system version that supports POWER9 and the latest POWER10 hardware. This version introduced diverse new features and capabilities for improving security and system administration. It is predicted that IBM will support this version till 2030 and beyond, keeping business platforms optimized and secure with additional advancements in the near future.

IBM i continues to be widely used in mission-critical applications across various industries. Many businesses, especially in banking, finance, insurance, healthcare, manufacturing, and retail, rely on IBM i for its stability, security, and seamless integration with enterprise systems. Banks and financial institutions use IBM i to handle high-volume transactions securely, while many enterprises leverage it for ERP (Enterprise Resource Planning) systems, supply chain management, and data analytics. The platform’s ability to support modern programming languages, cloud integration, and AI-driven applications ensures its continued relevance in today’s technology landscape.

Conclusion: The Future of IBM i Technology Systems

As per the 2024 IBM i Marketplace Survey, the IBM i community demonstrates a strong commitment to future investments. The survey reveals that a significant portion of respondents plan to upgrade their systems: 38% intend to enhance their Power Systems hardware, 23% aim to update their IBM i software, and an additional 23% plan to upgrade both. These figures suggest that the IBM i user base is proactive in maintaining and advancing its technological infrastructure.

Additionally, IBM, in November 2024, did provide insights about the release of the POWER11 processor sometime in the third quarter of 2025. POWER11 will be built upon POWER10’s foundation but will also include DDR5 memory support via the Open Memory Interface (OMI) and integrate IBM’s “Spyre” AI accelerators. These advancements aim to optimize performance for enterprise applications, particularly in AI and data-intensive tasks. These pieces of news indicate a positive outlook for the platform’s growth and sustainability in the coming years.

With these advancements, businesses relying on IBM i will increasingly seek AS400 development services and solutions to modernize applications, enhance efficiency, and ensure seamless integration with emerging technologies.

With IBM’s continued innovation, do you think the IBM i platform will support the evolving technologies of the future to align with the rising demands of this competitive landscape? Share your thoughts and experiences in the comments below!