Int 10h, 1017h          Read Block of DAC Registers                 MCGA, VGA

    Returns the value of one or more consecutively numbered color
    (DAC) registers.

        Entry   AX    = 1017h
                BX    = Number of first color register
                CX    = Number of registers
                ES:DX = Buffer (of size CX * 3)

        Return  Buffer updated with red-green-blue values