Language Environment supports OS PL/I Version 1 Release 5.1 main load module with the following restriction:
The ZAPped main load module, including one that contains the OS PL/I fast initialization and termination feature, continues to run under OS PL/I Version 1 Release 5.1 and Version 2. When the ZAPped main load module contains the OS PL/I fast initialization and termination feature, it always dynamically loads the OS PL/I run-time initialization routine IBMBPIIA once. IBMBPIIA is not deleted until the task terminates. This one-time loading of IBMBPIIA might affect the performance of your application. If you put IBMBPIIA in LPA, the performance effect can be minimized.
The ZAPped main load module is supported by Language Environment unless the load module contains the OS PL/I fast initialization and termination feature. Language Environment always dynamically loads the initialization and termination routines. If you put the Language Environment library routines and CEEBLIIA in LPA(E) as recommended in z/OS Language Environment Installation and Customization under OS/390 and z/OS Language Environment Customization, the performance effect can be minimized.
The ZAPped main load module is not supported under OS PL/I Version 1 Release 5.1 or Version 2. It is supported only under Language Environment.
If you do not ZAP your main load module, read OS PL/I Routine Replacement Tool to understand what else you can do. You can also recompile your application with Enterprise PL/I or OS PL/I Version 2. See Object and Load Module Considerations to understand how Language Environment supports OS PL/I object and load modules.
The sample ZAP is available in the IBM Support Center for customers who do not have Language Environment but want to prepare to migrate to Language Environment.