NUCLSTxx is provided as an alternative to the NMLDEF macro. With
NMLDEF, you identify modules to be added to the nucleus by creating
a set of tables, called nucleus module lists (NMLs). You can use either
NUCLSTxx or NMLDEF to customize the nucleus. However, you might prefer
to use NUCLSTxx for the following reasons:
- NUCLSTxx is easier to code than NMLDEF.
- NUCLSTxx resides in SYS1.PARMLIB (or SYSn.IPLPARM — wherever
LOADxx resides). NMLs must reside in SYS1.NUCLEUS.
- You can use different NUCLSTxx members to load different SYS1.NUCLEUS
members into the nucleus region. Therefore, NUCLSTxx provides you
with greater flexibility than NMLDEF in customizing the nucleus.
For information about the NMLDEF macro, see z/OS MVS Programming: Authorized Assembler Services Guide.