User-written Dynamic Support Programs

JES3 dynamic support programs (DSPs) control JES3 processing. Some primary DSPs (such as MAIN) directly relate to a job's execution. Other DSPs (such as Dump Job and Disk Reader DSPs) provide functions or services that can be called by a system operator.

In addition to the JES3 DSPs, you can create your own DSPs and add them to the system. Such DSPs run enabled in supervisor state, and under protection key 1. They become part of JES3 and JES3 expects them to use the same programming conventions as JES3 DSPs supplied by IBM.