Re: Re: IEF488I IPLASM - SYSPUNCH MUST WAIT FOR UNIT 00D

On Sat, 27 Mar 2010 00:28:49 -0000, mstramba2000 wrote:

>And MVT didn't complain about the punch being unavailable.

But if you had started a writer to it then it would have.

That's what a Job Entry Subsystem does for MVS - it's
a way of having readers and writers going all interfacing
to the same SPOOL (amongst other things), so you do
not have to start a reader for each card reader, and a
writer for each printer and punch.

When such readers and writers are going, they allocate
the device they drive, so that device is no longer available
for use by other jobs at the same time.  And that's why
they invented SPOOLing....

Cheers,
Greg