z/OS has had for a long time something called the SSI, the "SubSystem Interface", which implicitly defines a specific kind of subsystem. Yes, it is an overloaded word, but given the original question, there's really no confusion about what is meant here. For searching, you probably want to include some terms like IEFSSIREQ (not exactly that).
There are a number of SSI requests that have been un-documented, including all of those needed to support SUBSYS=. The old documentation can be found (maybe), but the CBT and JES2 suggestions are likely anyone's best chance to work out how it works. I have worked on developing such a thing, and I can say that it can be difficult. I do not know what IBM's corporate policy is on doing this. I presume they un-documented it for a reason. sas ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
