This chapter describes some of the z/OS system services and program development facilities that assist you in developing your assembler program. It provides the following information:

• Adding definitions to a macro library.
• Using cataloged procedures.
• Overriding statements in cataloged procedures.
• Saving and restoring general register contents.
• Ending program execution.
• Accessing execution parameters.
• Combining object modules to form a single program module.
• Modifying program modules.