INT 31H 0507H: Set Page Attributes

                                                    Compatibility: DPMI 1.0+ 
 Expects: AX     0507H
          ESI    memory block handle (as obtained via INT 31H 0504H)
          EBX    base offset of page(s) to modify
          ECX    number of pages
          ES:EDX address of buffer containing attributes to use
 Returns: CF    NC (clear) if successful
                else AX  = DPMI Error Code
                     ECX = number of pages that were modified
    Info: This sets attributes of one or more pages within a block of
          linear memory allocated via INT 31H 0504H.

          This can be used to modify read/write attributes or commit an
          uncommitted block, etc.

   ES:EDX on entry, this buffer contains attribute settings, as described
          under INT 31H 0506H.

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