Int 31 Fn 0004  P - Dpmi 0.9+ - Lock Selector                              [E]

   AX = 0004h
   BX = selector to lock (prevent paging)

Return: ???

Note:  although marked as reserved in versions 0.9 and 1.0 of the DPMI
     specification, this function is called by MS Windows TASKMAN,
     PROGMAN, and KERNEL

See Also: AX=0005h,AX=0600h