用STC89C51单片机键盘输入任意一个8位的数字，然后在两个数码管（加起来）上显示出来，C语言程序怎么写？

#include<reg51.h>
#define uchar unsigned char;
uchar LED1,LED2,LED3,LED4;
uchar keyval,calflag,s_dat,d_dat;
uchar distab[]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90,0x88,0x83