void setup() {
  Serial.begin(115200);
  randomSeed(analogRead(A0));
}

void loop() {
  int i, j, x = random(256), y = random(256);

  showbits(x);
  Serial.print(" || ");
  showbits(y);

  Serial.print(" (");
  pad (x);
  Serial.print(x);
  Serial.print(" || ");
  pad (y);
  Serial.print(y);
  Serial.print(") = ");
  Serial.print(x || y, BIN);

  Serial.println();
  delay(250);
}

void showbits(byte val) {
  for (int i = 7; i >= 0; i--)
  Serial.print(bitRead(val, i));
}

void pad(int val) {
  if (val < 100) Serial.print(" ");
  if (val <  10) Serial.print(" ");
}