Use Information

The following are a few examples of how a program running in an address space started under the master subsystem can, once it has obtained a job ID, use the primary subsystem (JES) services:

Allocate an internal reader to submit jobs that run under JES. See z/OS MVS Programming: Assembler Services Guide for more information on the internal reader.
Allocate a SYSOUT data set (SSI function code 1) so that the program can retrieve a data set after using SSI function code 1.

While the address space might have been started under the master subsystem before JES initialization, the Request Job ID SSI call is honored only after JES is initialized.

Because the address space was not started under JES control, JES does not have an internal job structure for the address space. Use of SSI function code 20 establishes the necessary structure so that subsequent requests for JES services for that address space may be performed properly.