...chessclock...

// chessclock
// (c) Thad 2000
// http://thad.notagoth.org/contact/
string msg,side[2];
main()
{
  int count,start;
  int t,ot,n;
  int p,players[2];
  side[0]="White";
  side[1]="Black";

  graph_on();
  textattr(7,1,0);
  textalign(11);
  rect(0,0,0,160,160,0);
  text(80,80,"...chessclock...");
  players[0]=
  players[1]=
  60*(int)gets("minutes?");
  while(1)
  for(p=0;p < 2;p++){
    n=count=players[p];
    ot=start=seconds();
    t=0;
    while(event(0)!=3 && n > 0){
      t=seconds();
      if(t > ot){
        while(ot++ < t){
          n=count-(ot-start);
          rect(3,
            (n%10)*16,144*p,
            (n%10)*16 + 15,144*p+15,0);
        }
        ot=t;
        msg = side[p]+": "+
          format(
            (n/60)+(n%60)*0.01,2
          );
        text(80,40+(80*p),msg);
      }
      else sleep(50);
    }
    beep(1);
    players[p]=n;
    if (n<=0){
      msg=side[p] + " out of time! ";
      text(80,40+(80*p),msg);
      beep(1);beep(2);beep(5);
      waitp();exit();
    }
  }
}