#define STARTX 64 
#define ENDX   576 

int osc() {
  int temp;
  int x;
  static char oscmode;
  long lastpos = total_samples;
  char y, skip = 0;
  char _lxs[ENDX];
  char *lxs = _lxs;
  for (x = 0; x < ENDX; x ++) _lxs[x] = 0;
  x = STARTX;
  while (!Done) {
    if ((x == (ENDX-1) && skip++ > 7) || oscmode == 2) {
      skip = 0;
      refresh_screen(filesize_hbytes, total_samples,  
        samplerate, looping);
      gotoxy(17,9);
      textattr(7);
      switch (oscmode) {
        case 0: cprintf("Accurate "); break;
        case 1: cprintf("FAST     "); break;
        case 2: cprintf("Off      "); break;
      }
      if (kbhit()) switch(getch()) {
        case 27: Done++; break;
        case 'D': case 'd': 
          textmode(3);
          cprintf("Entering DOS shell... Type EXIT to return\r\n");
          system("");
        return 1;
        case 'O': case 'o': 
          if (++oscmode > 2) oscmode = 0; 
          if (oscmode == 2) {
            lxs = _lxs;
            for (x = STARTX; x < ENDX; x ++) {
               temp = 240 + *lxs; 
               asm mov bx, temp
               asm mov ax, x
               #include "pixeloff.h"
               lxs++;
            }
            x = STARTX;
            lxs = _lxs;
          }
        break;
        default: break; 
      }
    }
    if (oscmode != 2) {
      if (!oscmode && lastpos == total_samples) continue;
      lastpos = total_samples;
      x ++;
      lxs++;
      if (x == ENDX) {
        lxs = _lxs;
        x = STARTX;
        while(!(inportb(0x3da) & 0x08));
        while(inportb(0x3da) & 0x08);
      }
      y = cb>>1;
      if (y > 0) y -= 64; 
      else if ( y < 0) y += 64;
      temp = 240+(*lxs); 
      asm mov ax, x
      asm mov bx, temp
      #include "pixeloff.h"
      *lxs = y;
      temp = 240+y;
      asm mov ax, x
      asm mov bx, temp
      #include "pixelon.h"
    }
  }  
  while(kbhit()) getch();
  return 0;
}