Library /sys$common/syshlp/sda.hlb SET, PROCESS, /SYSTEM  *Conan The Librarian (sorry for the slow response - running on an old VAX)

     Specifies the new current process by the system process control block.
     The system PCB and process header (PHD) are dummy structures that are
     located in system space and contain the system working set, global
     section table, global page table, and other system-wide data.