let textHistory = [];

​

function setup() {

  createCanvas(windowWidth, windowHeight);

}

​

function draw() {

  background(220);

  if (frameCount % 20 === 0){

    textHistory.reverse();

    textHistory.push(randomText());

    textHistory.reverse();

    textHistory = textHistory.slice(0, 10);

  }

  fill(0);

  textSize(32);

  textAlign(LEFT, TOP);

  for (var i=0; i<textHistory.length; i++){

    text(textHistory[i], 30, i * 30 + 30);

  }

}

​

function randomText(){

  var t = "";

  for (var i=0; i<20; i++){

    t += (random(0, 3) < 1) ? " " : String.fromCharCode(random(97, 122));

  }

  return t;

}