Int 31 Fn FF1D  P - Causeway - "unlockmem" - Unlock Region Of Memory       [E]

   AX = FF1Dh
   BX:CX = starting linear address
   SI:DI = size of region in bytes

Return: CF clear if successful
   CF set on error
Desc:  allow memory to be swapped out by the virtual memory manager

Note:  locks are applied on 4K page boundaries, so memory above and below
     the specified region may be unlocked as well

See Also: AX=FF1Bh,AX=FF1Eh