INT 31H 0600H: Lock Linear Region

                                                    Compatibility: DPMI 0.9+ 
 Expects: AX    0600H
          BX:CX starting linear address of memory to lock
          SI:DI size, in bytes, of region to lock
 Returns: CF    NC (clear) if successful; else AX = DPMI Error Code
    Info: Locks a region of linear memory (thereby ensuring that it won't
          be moved around or swapped out).

          DPMI maintains a lock count.  You should use INT 31H 0601H to
          unlock the region as soon as possible.

          This also locks any partial page at the start and end of the

See Also: DPMI API
          INT 2fH: Multiplex Interrupt
          DOS Functions