Int 10 Fn 4F05  - Vesa Supervga Bios - Cpu Video Memory Control            [V]

   AX = 4F05h
   BH = subfunction
       00h select video memory window
       DX = window address in video memory (in granularity units)
       01h get video memory window

       Return: DX = window address in video memory (in gran. units)
   BL = window number
       00h window A
       01h window B

Return: AL = 4Fh if function supported
   AH = status
       00h successful
       01h failed
BUG:   Phoenix S3 Trio64V+ v1.02-02 reportedly returns garbage in DX for
     subfunction 01h

See Also: AX=4F01h,AX=4F06h,AX=4F07h,AX=7000h/BX=0004h