Differences Between SSI Function Codes 1 and 79

Although both the SYSOUT Application Program Interface (SSI Function Code 79) and Process SYSOUT (SSI Function Code 1) allow applications to retrieve SYSOUT from JES spool using a variety of criteria, there are several important differences between the two function calls. IBM® recommends that applications use the SAPI, as it is richer in function, as well as having better performance characteristics than the Process SYSOUT Call.

Some of the differences that SAPI provides are:

The ability to multitask data set selection and processing calls from within an application.
A richer selection criteria, including the use of wildcard characters for attributes.
A greater number of SYSOUT data set characteristics returned to the application than does Process SYSOUT.
The application has the ability to retrieve information contained in the scheduler work blocks (SWBs)
A greater degree of modification ability of selected SYSOUT data sets.
A count facility that Process SYSOUT does not provide.