Controlling started tasks

A started task, like a job, is a basic unit of work for the system. However, started tasks differ from jobs in that started tasks are always demand-selected; that is, the operator or a program must take action to initiate a started task.

There are several ways to initiate started tasks:

With a START command.
Via TSO/E logons. For information on using TSO/E logons, refer to the TSO/E publications.
With ASCRE (address space create) macros in programs. For information on how to use the ASCRE macro, refer to z/OS MVS Programming: Extended Addressability Guide.

Both the START command and the ASCRE macro create an address space. A START command and an ASCRE macro started via a START command each will look for a program that has a procedure in SYS1.PROCLIB; that program will be the first to run in the ASCRE-created address space. Essentially, using ASCRE is similar to a started task.

For a started task, the system:

Locates the JCL that starts the task
Defines the task's address space
Processes the JCL.

For a started task, operators can do the following:

Task	For information, refer to:
Cancel the started task	CANCEL command
Display status about the started task	DISPLAY command
Force the started task	FORCE command
Modify the started task	MODIFY command
Name the started task	"START Command" Starting a system task from a console (JOBNAME= parameter)
Start the started task	"START Command" Starting a system task from a console
Stop the started task	STOP command