ex2.c

c51学习的好书！

int counter;
void main (void) {
  counter = 0;
  while (1) { /* repeat forever */
    check_serial_io ();
    process_serial_cmds ();                   /* process serial input */
    check_kbd_io ();
    process_kbd_cmds ();                      /* process keyboard input */
    adjust_ctrlr_parms ();                    /* adjust the controller */
    counter++;                                /* increment counter */
  }
}