Int 31 Fn FF20  P - Causeway - "unlockmemnear" - Unlock App-relative Memo  [E]

   AX = FF20h
   ESI = starting application-relative linear address
   ECX = 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=FF1Eh,AX=FF1Fh