Just op-amps and FETs for the active components. The design from my memory was: - To get position, 2 integrators were applied to an adjustable voltage represen

Just op-amps and FETs for the active components. The design from my memory was: - To get position, 2 integrators were applied to an adjustable voltage representing gravity. - The FETs were used to set initial states of the integrators. - A comparator used to detect the table (y=0), flip the velocity and apply a scaling factor for restitution The math was actually quite simple given its just the standard velocity equations — the challenge was in handling state changes in the electronics. I looked around a little more and this video is a very close replica of what we built: https://www.youtube.com/watch?v=qt6RVrmvh-o https://www.youtube.com/watch?v=qt6RVrmvh-o