MSS emulates those MVS control blocks that are accessible to applications running in problem program state. The information stored in these control blocks is limited to that which has value and meaning to applications running in problem program state.
Control blocks are accessed in MSS in the same way as they are on a mainframe, by referencing the appropriate field in the Communication Vector Table (CVT). The address of the CVT is stored at absolute address 16 in memory, as it is on the mainframe.