#include"1602.c"
//#include <reg51.h>
//#include <at89x51.h>
#define uchar unsigned char

#define a P0_0
#define b P0_1
#define c P0_2
#define d P0_3
uchar getchar;
void set()
{
	TH0=0xfd;
	TMOD=0x20;
	//SMOD=0;
	PCON=0x80;
	SCON=0x50;
	IE=0x90;
}
void chuankou()interrupt 4
{
	if(TI==1)
	TI=0;
	if(RI==1)
	{
		RI=0;
		getchar=SBUF;
		DisplayOneChar(1, 0, getchar);
	}
}

void main()
{	
	set();
	while(1)
	{
	if(a==0)SBUF=65;
	if(b==0)SBUF=66;
	if(c==0)SBUF=67;
	if(d==0)SBUF=68;
	}
	
	
}