At UW (University of Waterloo), our Real-time OS class projects used physical trains. Walking the halls of the Math & CS building, you could see kids "playing w

At UW (University of Waterloo), our Real-time OS class projects used physical trains. Walking the halls of the Math & CS building, you could see kids "playing with trains" all through the night quite routinely. It had the reputation of being one of the hardest CS classes in the undergrad curriculum.