Mainframe, MVS and zOS Discussion

Hi,

What is a zOS started task? I'm confused in this because I read that CICS etc are also sub-sysyem and are 'started-task'. Then what zOS itself be called?

There are different ways programs can get running under z/OS:
- a TSO user can log on
- a batch job can be submitted
- a start command can be issued on the console for a batch job
- a CICS transaction can be invoked
- etc

The third is called a started task. There are various restrictions on started tasks (as opposed to batch jobs). CICS can be run as a started task or a batch job. z/OS is the operating system. A subsystem is a component of z/OS that is doing something special (such as accessing terminals in the case of CICS).

Thanks Robert. So anything which gets "START" command 'in it' is a started task?

Pretty much -- but I think you missed the point that the START is executed on the console (or via SYS1.PARMLIB during IPL) -- you, for example, cannot issue a start command and expect a started task to run (unless you have console privileges on your system).