C编程演奏中文版“生日快乐歌”

有了《C编程控制PC蜂鸣器》一文的基础后，我们在其基础上修改函数入口参数，由原来的1个参数（频率）改为现在的2个（频率、延时<即该频率响多长时间>），然后就按照节奏实现中文版的“生日快乐歌”，其源码如下：

#include <unistd.h>
#include <sys/io.h>

/* The clock frequency of the i8253/i8254 PIT */
#define PIT_TICK_RATE 1193182ul

void beep(unsigned int freq, unsigned int delay)
{
        unsigned int count = PIT_TICK_RATE / freq;
        iopl(3);

        outb_p(0xB6, 0x43);
        outb_p(count & 0xFF, 0x42);
        outb((count >> 8) & 0xFF, 0x42);
        outb_p(inb_p(0x61) | 3, 0x61);
        usleep(1000*delay);
        outb_p(inb_p(0x61) & 0xfc, 0x61);

        iopl(0);
}

void play(unsigned int* freq, unsigned int* time)
{
        int i;
        for(i=0;freq[i]!=0;i++)
        {
                beep(freq[i], time[i]);
        }
}
int main(int argc,char * argv[])
{
        /*Happy Birthday chinese version*/
        unsigned frequency[]=
        {
                392,392,440,392,523,494,
                392,392,440,392,587,523,
                392,392,784,659,523,494,440,
                698,698,659,523,587,523
        };
        unsigned delay[]=
        {
                375,125,500,500,500,1000,
                375,125,500,500,500,1000,
                375,125,500,500,500,500,1000,
                375,125,500,500,500,1000,
        };
        play(frequency, delay);

        return 0;
}

相应的Makefile文件内容如下：

all:
        make beep
#gcc -o beep beep.c

clean:
        rm -rf beep

对应的源码文件目录树如下：
/home/xinu/xinu/c_cpp/beep_song/
├── beep.c
└── Makefile
参考资料：
http://blog.csdn.net/sky_j123/article/details/19574955
http://www.cnblogs.com/sankye/articles/3219479.html