Int 4B Fn 8105  - Virtual Dma Specification - Scatter/gather Lock Region   [d]

   AX = 8105h
   DX = flags
       bits 0-5 reserved (zero)
       bit 6: EDDS should be returned with page table entries
       bit 7: only present pages should be locked (not-present pages
           receive entry of 0000h)
       bits 8-15 reserved (zero)
   ES:DI -> Extended DMA descriptor structure (see AX=8102h)
       region size, linear segment, linear offset, and number avail
       fields set

Return: CF clear if successful
       EDDS number used field set
       if DX bit 6 set, lower 12 bits of BX = offset in first page
   CF set on error
       AL = error code (see AX=8102h)
       EDDS region size field filled with max length in bytes that can be
       locked and described in the EDDS table
BUG:   Windows 3.0 in enhanced mode may return zero instead of the physical
     page address for pages which were originally not present

See Also: AX=8103h,AX=8106h