Evolution of the AS400 and ISeries

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In 1988, IBM introduced the AS400® as a server solution for midsize businesses and departments within larger enterprises. Over time, IBM realized that in order to fulfill their vision of replacing PC and Unix servers throughout organizations worldwide, the AS400 would need to be easily integrated with distributed networks and web applications. To accomplish this, IBM redesigned the AS400 to use eServer i5 servers with POWER5® processors, and rebranded the AS400 as the IBM iSeries®.

The strategic features of the iSeries include:

– Integration
– Virtualization
– Optimization
– Security
– Support for a wide range of application development media
– Simplified administration
– Scalability


The iSeries includes an integrated standards-based DB2 database for managing enterprise data. The iSeries includes an integrated Apache HTTP server and web application server for web-based application deployment, and a Java/J2EE web-services environment for web application development. Many popular development technologies are also integrated with the iSeries, including SQL, mySQL, .NET, DRDA/CLI, ODBC and JDBC. Windows, UNIX, and NFS file systems are supported.


iSeries virtualization allows organizations to manage multiple applications and processes using the integrated workload manager, shared processor pools and automatic performance balancing.


The clustered architecture, transaction logging and mirroring capabilities of the iSeries provide flexibility and reliability. IBM also integrates tools for managing clusters.


The security model for the IBM iSeries is object-based, which simplifies deployment and enhances the system’s ability to resist viruses. The iSeries can not only detect intrusion, but has built-in methods to prevent it and provides an audit log to track potential security risks. Both production and backup data are encrypted, and SSL VPN is used to ensure the network is secure.

Application Development

With support for services oriented architecture (SOA), IBM Rational development tools, and UNIX application runtime, the iSeries provides a myriad of options for application development. Languages supported by the iSeries include C, RPG, COBOL, C++, Java, EGL, PHP and CL.


Storage management is integrated into the system and the system hosts managed storage for I, AIX, Linux, Windows and VMware. The administration module is web-based for easy access. IBM Systems Director provides a single, consistent user interface for managing both physical and virtual systems.


With many systems, the system’s technology is integrated with the machine’s interface, meaning that upgrades are disruptive to daily business activities. With the iSeries however, upgrades are automatic, and the separation of technology from interface makes the process virtually seamless. With IBM’s Capacity on Demand feature, you can activate only the processors and memory that you need, making the iSeries scalable, flexible and cost efficient.


To communicate with the IBM AS400 or iSeries from your Windows PC, you will need to use a terminal emulator. Terminal emulators intercept and translate the 5250 data stream so that your PC can understand, display, and manipulate it. One such terminal emulator is Zephyr’s PASSPORT, which provides TN5250 and TN5250E emulation.


The key to the success of the AS400 iSeries has been the integration of relational database, security, web services, networking and storage management. According to IBM, over 5,000 ISV solutions are supported on the iSeries. Virtualization support allows organizations to run various applications simultaneously, allowing the organization to make the most of its resources.

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