Is it possible to port existing applications from the mainframe or Os/2? Are there major changes required to do this?

Yes, it is possible to port the existing applications from the mainframe or Os/2. Also, you can port with minimum alterations. However, the following modifications are required-

• Modifying references to disk file names.
• Modify the statements in the program that can execute operating system commands. EXECIO and GLOBALV are two exceptional mainframe commands that can be accessed from within a Uni-REXX program.
• Modifications in parts of the programs that stack data for use by some non-Rexx program.
• Alterations in the stack available to all processes. The alteration here is very basic and a technical support is available to provide guidance and suggestions.