The platform was first introduced as the AS/400 (Application System/400) on June 21, 1988 and later renamed to the eServer iSeries in 2000. The IBM System i is IBM's previous generation of midrange computer systems for IBM i users, and was subsequently replaced by the IBM Power Systems in April 2008.
One feature that has contributed to the longevity of the IBM System i platform is its high-level instruction set (called TIMI for "Technology Independent Machine Interface" by IBM), which allows application programs to take advantage of advances in hardware and software without recompilation.
The AS/400 has been a very robust platform in the past decades, offering the compatibility mentioned above, which has allowed customers to keep building up their legacy applications with no or minimum migration effort involved.
But times have changed.
Now, one of the biggest decisions IT managers have to make is how and where to run data center applications in order to lower costs and increase business agility.
There are multiple options including server virtualization, internal clouds, public clouds and external private clouds.
If you plan to keep maintaining your legacy applications written in RPG, COBOL and CL for the next few years, but you also want to move the AS/400 workloads to Azure, there is a very interesting solution: Infinite Corporation.
Infinite provides a very similar development and production environments as the AS/400: menus, command line, user interface (green screens). The software product is called Infinite i. It is a suite of utilities, compilers and services that allow RPG and COBOL applications run and perform in Azure as if they were in the AS/400. The source code has to be recompiled in Azure to be deployed natively.
For development, you still have available utilities like PDM (Programming Development Manager), SEU (Source Entry Utility), DFU (Data File Utility) and SDA (Screen Design Aid), where you can write screens (display files), physical and logical files, source code (RPG, COBOL, CL) and execute and debug programs.
In order to run on Azure, the RPG, COBOL and CL applications are converted to C (business rules) and JAVA (user interface). You are also free to modify the C and JAVA source code rather than the legacy source code.
The DB2 database is replicated in Azure by converting it to either SQL Server or Oracle to run on Windows Server or Linux.
Advantages:
- Reduce hardware and software infrastructure costs
- Modernize applications source code and databases
- Improve the maintenance and deployment of the converted applications
- Smooth transition from the AS/400 to Azure
For more information, please contact the AS/400 Division at the Azure Global Engineering team.