一个简单的端口访问实例——扬声器发生程序。由于Win2000及以上操作系统提高了对主板访问的安全性，所以此程序只能在Win98下编译运行。-a simple example of the port visit -- loudspeakers occurred procedures. Since Windows 2000 operating system and above board increased the security of the visit, this procedure can only build run under Win98.