Abstract for MVS™ Programming: Assembler Services Guide
Purpose of this information
This information describes the operating system services that an unauthorized program can use. An unauthorized program is one that does not run in supervisor state, or have PSW key 0-7, or run with APF authorization. To use a service, the program issues a macro. For detailed information for coding the macros, see the z/OS® MVS Programming: Assembler Services References.
Who should use this information
This information is for the programmer who is coding in assembler language, and who needs to become familiar with the operating system and the services that programs running under it can invoke.
The information assumes that the reader understands system concepts and writes programs in assembler language.