472   cmp  al, #0x04  variable
479   mov  al, #0x13  variable
538   mov  al, #0x01  variable
553   mov  al, #0x12  variable
556   mov  al, #0x07  variable
559   in   al, dx  variable
560   and  al, #0xbd  variable
563   or   al, #0x02  variable
567   or   al, #0x40  variable
569   out  dx, al  variable
575   mov  al, #0x17  variable
578   in   al, dx  variable
579   or   al, #0x03  variable
582   in   al, dx  variable
584   mov  al, #0x10  variable
587   in   al, dx  variable
588   or   al, #0x01  variable
591   mov  al, #0x20  variable