Let's start by saying "if you want to know if you are prior to z/OS 1.12 then simply query bit CVTZOS_V1R12". If that bit is off, then you are prior to z/OS 1.12. Maybe that suffices -- if you are prior to z/OS 1.12 then you know that a subspace cannot access storage above 2G (although a non-subspace could).. I don't know if there's a bit that RSM provided indicating that the APAR that was mentioned has been installed. Testing for the release might not be as efficient as you desire, but at least it works. You might find it necessary to have your caller tell you if they are in the state you are interested in.
I'm not sure that the terminology used is letting the OP ask the right question. There is no such thing as "subspace mode" architecturally. It's not clear whether the OP is referring to "subspace active" or "reduced authority" both of which are potentially applicable, or even to a "subspace task" (a software term). Neither subspace-active nor reduced-authority state is something that can be in a z/OS control block because a suitably authorized program can change that on its own via the BSG and/or BSA instruction. Architecturally the state is kept in the dispatchable unit control table (DUCT) which is an architected block. I strongly discourage you from writing a program that accesses the DUCT as that is the sort of block that sometimes changes from machine to machine (and the operating system would be responsible for adapting to such changes; applications might have difficulty keeping up). STCBSST is not a programming interface. It means that the task is a subspace task (i.e., has subspace capabilities). It does not have any bearing on whether the task is currently subspace-active or reduced-authority although I would be surprised if you could be in either of those two states without having STCBSST on. For what it's worth, if you abend, bit SDWASSA will be on when the abend occurred while subspace-active. SDWABSA will be on for an ESTAE-type recovery routine (not for an FRR) when the abend occurred while in reduced authority mode. Peter Relson z/OS Core Technology Design ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: INFO IBM-MAIN
