// get two numbers; consider key D as enter; 
//substract them; display the difference on quad 7-seg
// If difference is less than (-999) or greater than (9999) display (EEEE)

#include "ecen.h"

void setup(){
    volatile char *F_dir=0x30, *K_dir=0x107, *A_dir=0x21, *B_dir=0x24;
    *F_dir=0xff, *K_dir=0x00, *A_dir=0xff, *B_dir=0xff;
    Serial.begin(9600);
}

void loop(){
  int num_a, num_b, dif;
  volatile long k;

  num_a = getTarget();

  num_b = getTarget();

  dif = num_a - num_b;
  if((dif>9999)|(dif<(-999))){
    outB(0xf0);
    outA(0x79);
    for(k=0;k<600000;k++);
    outB(0xff);
    } else if((dif<=9999)&&(dif>=-999)){
  outB(0xff);
  for(k=0;k<50000; k++);
  for(int i=0; i<8000; i++)
  printTarget(dif);
  }
}