Administering Facility Security › Protecting Facilities › Single Versus Multiple User Address Space Systems

Single Versus Multiple User Address Space Systems

Under TSO each signed on user gets his own address space, hence, single user address space. On the other hand, under CICS, for example, each user signed on to a CICS region is given part of the region's block of space, hence, multiple user address space. Moreover, when a user requests access, standard CICS will only identify to MVS the Security Record for the region involved, not the specific user's Security Record. This procedure is typical of multiple user address space systems.

See your Implementation: CICS and Implementation: TSO guides for a more detailed description of single and multiple user address space.