我是在IBM SupperOne下用的,参考一下;
asm
push dx
push ax
mov dx,240h
mov al,30h
out dx,al
mov dx,241h
in al,dx
and al,02h
jnz @@next
mov dx,240h
mov al,28h
out dx,al
mov dx,241h
mov al,04h
out dx,al
mov dx,240h
mov al,29h
out dx,al
mov dx,241h
mov al,01h
out dx,al
@@next: pop ax
pop dx
end