Int 31 Fn 0601  P - Dpmi 0.9+ - Unlock Linear Region                       [E]

   AX = 0601h
   BX:CX = starting linear address
   SI:DI = size of region in bytes

Return: CF clear if successful
   CF set on error
       none of the memory is unlocked
       AX = error code (DPMI 1.0+) (8002h,8025h) (see #2814)

Notes: pages at beginning and end will be unlocked if the region overlaps them
   memory whose lock count has not reached zero remains locked

See Also: AX=0005h,AX=0600h,INT 21/AX=251Bh,INT 21/AX=EB07h