Macros and callable services are programming interfaces that application programs can use to access MVS™ system services. This chapter provides general information and guidelines about how to use the macros and callable services accurately and efficiently. For more specific and detailed information about coding a particular macro or callable service, see the individual service description in this information.
Some of the topics covered in this chapter apply only to macros, some apply only to callable services, and some apply to both. This chapter uses the word "services" when referring to information that applies to both service types. When information applies only to one type or the other, the particular service type is specified.
The following table lists the topics covered in this chapter and whether the topic applies to macros, callable services, or both:
| Topic | Service Type |
|---|---|
| Compatibility of MVS macros | Macros |
| Addressing mode (AMODE) | Both |
| Address space control (ASC) mode | Both |
| ALET qualification | Both |
| User parameters | Macros |
| Telling the system about the execution environment | Macros |
| Specifying a macro version number | Macros |
| Register use | Both |
| Handling return codes and reason codes | Both |
| Handling program errors | Both |
| Handling environmental and system errors | Both |
| Using X-macros | Macros |
| Macro forms | Macros |
| Coding the macros | Macros |
| Coding the callable services | Callable Services |
| Including equate (EQU) statements | Callable Services |
| Link-editing linkage-assist routines | Callable Services |
| Service summary | Both |