It's not like they just hit the precalculated coordinates on the floor with the feet, they used gyros and hand-written algorithms to compute all the forces in real time, just like today those Unitree bots do with GPU trained algorithms. They're fundamentally the same. Very little had changed.
Who's making up that hallucination? This isn't even the second time I've come across those "preprogrammed" BS.
https://en.wikipedia.org/wiki/Running