const int shift_table[16] = {
  -0x80, -0x40, -0x20, -0x10, -0x8, -0x4, -0x2, - 0x1,
   0x1, 0x2, 0x4, 0x8, 0x10, 0x20, 0x40, 0x80  
};

  static unsigned int_count, cur_len;

void interrupt new_isr() {
  static unsigned int a_xs[160];
  static unsigned char a_xc[160];
  static int xcount = 319;
  static unsigned int *xs = a_xs;
  static unsigned char *xc = a_xc;
  static unsigned char far *screenpos;
  if (!skip) {
    if(int_count >= cur_len) {
      int_count = 0;
      accum = 0x80;
      i++;
      _CH = playlist[i];
      if (_CH == 0) {
        _CH = *playlist;
        i = 0;
      }
      MemoryPointer = patterns[_CH];
      cur_len = lengths[_CH];
    }
    int_count++;
    cc = *(MemoryPointer++);
    accum -= shift_table[(cc >> 4) & 0x0f];
    cb = (((accum) < 0) ? 0 : ((accum) > 255) 
      ? 255 : accum);
    skip = 1;
  }
  else {
    accum -= shift_table[cc & 0x0f];
    cb = (((accum) < 0) ? 0 : ((accum) > 255) 
      ? 255 : accum);
    skip = 0;
  }
  asm {
    mov ax, cb
    mov cx, dev
    cmp cx, 0
    jne no_soundblaster
    mov bl, al 
    mov dx, out_port
  } 
  sbloop1:
  asm {
    in  al, dx
    test al, 80h
    jnz sbloop1
    mov al, 10h
    out dx, al 
  }
  sbloop2:
  asm {
    in  al, dx
    test al, 80h
    jnz sbloop2
    mov al, bl
  }
  no_soundblaster:
  asm {
    mov dx, out_port
    out dx, al 
  }
  if (timer_pos++ == 440) {
    timer_pos = 0;
    old_isr();
  }
  else {
    asm mov al, 20h
    asm out 20h, al
  }
  if (osc) {
    if (xcount >= 319) {
      xs = a_xs;
      xc = a_xc;
      xcount = 0;
    }
    if (*xc != 15 && *xs) pixel(xcount,*xs) = *xc;
    *xs = (cb >> 3) + 166;
    screenpos = (char far *) 0xA0000000L + xcount + 
      (*xs << 8) + (*xs << 6);
    *xc = *screenpos;
    if (*xc != 15) 
      *screenpos = 9;
    xc++; xs++; xcount += 2;
  }
} /* New ISR */