Int 4B Fn 8107  - Virtual Dma Specification - Request Dma Buffer           [d]

   AX = 8107h
   DX = flags
       bit 0: reserved (zero)
       bit 1: data should be copied into buffer
       bits  2-15 reserved (zero)
   ES:DI -> DMA descriptor structure (see AX=8102h) with region size set
       (also region offset and region segment if DX bit 1 set)

Return: CF clear if successful
       DDS physical address and buffer ID set
       DDS region size filled with length of buffer
   CF set on error
       AL = error code (see AX=8102h)

See Also: AX=8108h