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

   AX = 8105h
   DX = flags (see #2895)
   ES:DI -> Extended DMA descriptor structure (see #2893,#2894)
         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 #2889)
       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

Bitfields for VDS flags:
Bit(s) Description (Table 2895)
 0-5   reserved (zero)
 6 EDDS should be returned with page table entries
 7 only present pages should be locked (not-present pages receive entry
     of 0000h)
 8-15  reserved (zero)