I am not sure if this will help, but here is a thread on the topic of SUBSYS writing. There are some interesting comments in this thread
http://bit.listserv.ibm-main.narkive.com/VpFYg60B/jcl-dd-subsys-how-to-write-the -subsys Lizette > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:[email protected]] On > Behalf Of [email protected] > Sent: Sunday, November 15, 2015 6:34 AM > To: [email protected] > Subject: Re: SUBSYS DD REVISITED > > Shmuel Metz wrote > "If you OPEN a DCB with a ddname allocated to a subsystem data set then OPEN > loads a compatibility interface and opens an ACB under the covers. The subsystem > sees only the ACB/RPL interface, not the DCB." > . > . > Where in z/OS publications is this documented ? > > ---------- Original Message ---------- > From: "Shmuel Metz (Seymour J.)" <[email protected]> > To: [email protected] > Subject: Re: SUBSYS DD REVISITED > Date: Sat, 14 Nov 2015 18:57:46 -0500 > > In <[email protected]>, on 11/14/2015 > at 04:28 PM, "[email protected]" <[email protected]> said: > > >Recently a question was posted regarding SubSystem Datasets, more > >appropriatly the use of a SUBSYS= parameter on a DD statement. > >//DD1 DD SUBSYS=(ssn,'parms'). > > There's a sample subsystem on the CBT tape. > > >However neither technology provides a PUT/WRITE function/exit. > > If you OPEN a DCB with a ddname allocated to a subsystem data set then OPEN > loads a compatibility interface and opens an ACB under the covers. The subsystem > sees only the ACB/RPL interface, not the DCB. > > >Each I/O from an application with the appropriate SUBSYS statement > >should be directed to my SubSystem Address Space. > > A subsystem does not require a separate address space. > > -- > Shmuel (Seymour J.) Metz, SysProg and JOAT ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
