let PROBABLILTY = 0.5;

​

// Intuitive implementation of

// the 10 print pattern

function setup() {

  // The original Commodore 64

  // character grid was only 40 x 25

  createCanvas(500, 500);

​

  // Approximation of the Commodore 64 style

  background(62, 67, 209);

  stroke(154, 156, 250);

  strokeWeight(2);

​

  noLoop(); // only draw once

}

​

function draw() {

  // Go row by row

  for (let y = 0; y < width; y += SPACING) {

    for (let x = 0; x < height; x += SPACING) {

      // Switch which "character"

      if (random(1) < PROBABLILTY) {

        line(x, y, x + SPACING, y + SPACING);

      } else {

        line(x, y + SPACING, x + SPACING, y);

      }

    }

  }

}

​