Int 10 Fn A000  - Ati Mach64 Bios - ???                                    [p]

   AX = A000h
   CL = ??? (bits 2-0 may not be 000)
   CH = ??? (81h or ???)
   DX = segment of ??? (if CH=81h)
   ???

Return: AX = ???

See Also: AX=4F10h/BL=00h,AX=A001h