#include <reg51.h>
#define uchar unsigned char
#define uint unsigned int
uchar i;
uint time;
code struct 
{
  int  position;
  char pattern;
} next[]=                                     /* item1 */	
  {{0,0x00},{200,0x01},{210,0x03},{400,0x02},{450,0xff}};
timer0() interrupt 1 using 1 { 	               /* item2 */
  TH0=(65536-8333)/256;
  TL0=(65536-8333)%256;
  time++;	                        	/* item3 */
  if (time==next[i].position) {
    if (next[i].pattern==0xff) i=time=0;	/* item4 */
    P1=next[i++].pattern;
  }
}
main() {
  P1=0;						/* item5 */
  time=0;
  i=1;
  TMOD=0x01;
  TH0=(65536-8333)/256;
  TL0=(65536-8333)%256;
  TR0=1;
  ET0=1;
  EA=1;
  for (;;) {
   }
}