Using Interrupt Functions in C++ Programs

  PRODUCT  :  Borland C++                            NUMBER  :  641
  VERSION  :  2.0
       OS  :  PC DOS
     DATE  :  August 12, 1992                          PAGE  :  1/2

    TITLE  :  Using Interrupt Functions in C++ Programs




  /************************************************************************
     example of installing an interrupt function in a C++ program
  ************************************************************************/
  #pragma option -w -w-par
  #include <conio.h>
  #include <dos.h>

  typedef void interrupt (*cast_isr) (...);

  void install(void interrupt (*faddr)(...), int inum);
  void interrupt mybeep(unsigned, unsigned, unsigned, unsigned,
                        unsigned, unsigned, unsigned, unsigned,
                        unsigned);
  void testbeep(unsigned char bcount, int inum);

  //-----------------
  int main(void)
  {
     install( (cast_isr)mybeep, 10);
     testbeep(3,10);
     cputs("beep");
     return 0;
  }

  //-----------------
  void install(void interrupt (*faddr)(...), int inum)
  {
      setvect(inum, faddr);
  }

  //-----------------
  void interrupt mybeep(unsigned bp, unsigned di, unsigned si,
                        unsigned ds, unsigned es, unsigned dx,
                        unsigned cx, unsigned bx, unsigned ax)
  {
     int i, j;
     char originalbits, bits;
     int bcount = 2000;

     bits = originalbits = inportb(0x61);
















  PRODUCT  :  Borland C++                            NUMBER  :  641
  VERSION  :  2.0
       OS  :  PC DOS
     DATE  :  August 12, 1992                          PAGE  :  2/2

    TITLE  :  Using Interrupt Functions in C++ Programs




     for (i = 0; i <= bcount; i++)
     {  outportb(0x61, bits & 0xfc);
        for (j = 0; j <= 300; j++);
        outportb(0x61, bits | 2);
        for (j=0; j<=300; j++);
     }
     outportb(0x61, originalbits);
  }

  //-----------------
  void testbeep(unsigned char bcount, int inum)
  {
     _AH = bcount;
     geninterrupt(inum);
  }

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  subject to the terms  of  the  No-Nonsense License Statement that
  you received with  the  Borland product to which this information
  pertains.