INT 31H 0603H: Relock Real-Mode Region

                                                    Compatibility: DPMI 0.9+ 
 Expects: AX    0603H
          BX:CX starting linear address of memory to relock
          SI:DI size, in bytes, of region to relock
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 Returns: CF    NC (clear) if successful; else AX = DPMI Error Code
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    Info: Relocks a memory region that was previously declared pageable via
          a previous call to INT 31H 0602H (mark real-mode region as
          pageable).

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