9-4.c

本书是单片机系列教材

/*9-4.c*/
#include<time.h>
#include<dos.h>
#define N1 64
#define N2 32
#define N4 16
#define N8 8
#define N16 4
#define END 0
enum NOTES
{
C10=131,D10=147,E10=165,F10=175,G10=196,A10=220,B10=247,
C0=262,D0=296,E0=330,F0=349,G0=392,A0=440,B0=494,
C1=525,D1=587,E1=659,F1=698,G1=784,A1=880,B1=988,
C2=1047,D2=1175,E2=1319,F2=1397,G2=1568,A2=1760,B2=1796
}song[]={
  D0,N4,E0,N8,D0,N8,C0,N4,A10,N4,G10,N8,E10,N8,G10,N8,A10,
  N8,C0,N2,A10,N4,A10,N8,C0,N8,G10,N8,A0,N8,E0,N8,G0,N8,
  D0,N2,E0,N4,D0,N8,E0,N8,G0,N4,E0,N4,G10,N8,E10,N8,G10,
  N8,A10,N8,C0,N2,A10,N4,A10,N8,C0,N8,A10,N8,A10,N8,D10,
  N8,E10,N8,G10,N2,D0,N4,D0,N4,G0,N4,A0,N8,G0,N8,F0,N2,G0,
  N2,A0,N4,G0,N8,E0,N8,D0,N8,E0,N8,C0,N8,A10,N8,D0,N2,E0,
  N4,G0,N8,E0,N8,G0,N4,E0,N4,G10,N8,E10,N8,G10,N8,A10,N8,
  C0,N4,A10,N4,A10,N8,C0,N8,D0,N8,A10,N8,C0,N8,E0,N8,D0,
  N1,END,END};
  main()
{
	int note=0,fre,dur,control;
    clock_t goal;
    while(song[note]!=0)
    {
      fre=song[note];
      dur=song[note+1];
      if(kbhit()) break;
      if(fre)
{
    outportb(0x43,0xb6);
    fre=(unsigned)(1193180L/fre);
	outportb(0x42,(char)fre);
    outportb(0x42,(char)(fre>>8));
    control=inportb(0x61);
	outportb(0x61,(control)|0x3);
  }
  goal=(clock_t)dur+clock( );
   while(goal>clock ( ));
   if(fre)
     outportb(0x61,control);
   goal=(clock_t)0;note=note+2;
  }
 }