If you want to get an idea of his approach look at the _astounding_ patch he made for Race Driving. He re-wrote the engine to essentially tween between frames b

If you want to get an idea of his approach look at the _astounding_ patch he made for Race Driving. He re-wrote the engine to essentially tween between frames because the original was more or less stuck at 5fps and certain things, like the position of your car and viewport when doing a loop-de-loop, were _hard coded_ into the game.