Which modules can be in the MVS link pack area?

A number of CICS® modules and user application program modules are available from the MVS™ link pack area.

CICS modules

The following CICS modules can be installed in the LPA:
  • Modules that can reside above 16 MB (for example, the CICS message table, DFHMGT). You can also install these modules in the extended link pack area (ELPA).
  • Modules that are optionally installed in the MVS link pack area; that is, a module that is not required in the MVS link pack area can be used only by the release of CICS to which it relates.
  • Modules that are eligible to be used from the MVS link pack area are listed in the CICS-supplied USERMODs. The USERMOD member for base CICS modules is DFH$UMOD, which is in the hlq.SDFHSAMP library. Refer to DFH$UMOD for a list of these modules, and to the details in LPA-required and LPA-eligible modules, to help you select the CICS modules that you want to install in the MVS link pack area.

User application programs

You can use user application programs from the MVS link pack area if they are read-only and meet one of the following criteria:
  • They are written in COBOL, do not overwrite WORKING STORAGE, and are compiled using VS COBOL II, or a later version. The CICS translator generates a CBL statement with the required compiler options.
  • They are written in PL/I (so they do not overwrite STATIC storage) and are compiled using one of the versions of PL/I for z/OS listed in High-level language support. The CICS translator inserts the required REENTRANT option into the PROCEDURE statement.
  • They are written in C/370, compiled with the RENT option, and link-edited with the RENT option.
  • They are written in assembler language, assembled with the RENT option, and link-edited with the RENT and REFR options.

Command-level user application programs compiled using a Language Environment-conforming compiler, or written in assembler language or C/370, can be loaded above 16 MB. For information about installing application programs, see Installing application programs.

A read-only module that can be above 16 MB is also eligible for the ELPA.