color black = color(0);
color white = color(255);

void setup(){
  size(320,240);
  // frameRate(300); // 60 by default
}

void draw(){
  loadPixels();
  for(int i=0; i<pixels.length; i++){
    if(random(1)<0.5){
      pixels[i] = black;
    }else{
      pixels[i] = white;
    }
  }
  updatePixels();
  fill(0,128);
  rect(0,0,60,20);
  fill(255);
  text(frameRate, 5,15);
}