Int 10h, 1103h          Select Displayed Alpha Font            EGA, MCGA, VGA

    Sets the font block specifier in text mode.

        Entry   AX = 1103h
                BL = Bits 4,1,0: No. of font block to use when
                                 bit 3 of attribute byte is 0
                     Bits 5,3,2: No. of font block to use when
                                 bit 3 of attribute byte is 1
                     Block no. = 0..3 (EGA/MCGA), 0..7 (VGA)

        Return  Nothing