SwSrvc Fn 0001H: Test Memory Region

 Expects: AX    0001H
          ES:BX address of first byte to test
          CX    size, in bytes, of memory region to test
 Returns: CF    Carry Flag is clear (NC) is successful and...
          AX    result code: 0000H = global memory
                             0001H = global and local memory
                             0002H = local memory
    Info: Use a FAR call to the switcher entry address (see INT 2fH 4b02H)
          to learn whether a particular block of memory is global or local
          to the current session.  Local memory areas are replaced whenever
          a session switch occurs.

          One use for this is to find out if your application or TSR
          program code is stored in global memory (started before the task
          switcher), or local memory (started in a task-switcher session).
          Global TSRs are never swapped out.

See Also: Switcher Services and Notifications
          INT 2fH 4bxxH (switcher functions)