直接看例子: IN AL,21H 从21H端口读取一字节数据到AL IN AX,21H 从端口地址21H读取1字节数据到AL,从端口地址22H读取1字节到AH MOV DX,379HIN AL,DX 从端口379H读取1字节到AL OUT 21H,AL 将AL的值写入21H端口 OUT 21H,AX 将AX的值写入端口地址21H开始的连续两个字节.(port[21H]=AL,port[22h]=AH) MOV DX,378H OUT DX,AX 将AH和AL分别写入端口379H和378H 总结:…