I recently stumbled upon a good video showing some old delay line memory:
    <a href="https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=N9cUbYII5RY" rel="nofollow">https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=N9cUbYII5RY</a>