函数名:sound
功能:以指定频率打开pc扬声器
用法:voidsound(unsignedfrequency);
程序例:
/*emitsa7-hztonefor10seconds.
yourpcmaynotbeabletoemita7-hztone.*/
#include<dos.h>
intmain(void)
{
sound(7);
delay(10000);
nosound();
return0;
}