I didn´t count how often you mentioned AI in this post, but the programs of the 1990 had nothing to do with AI, AI was not even a common term used in that time (I know, as I was there). The "super computers" were just brute force calculating positions, but I guess not a single neural network was in place back then. Just take this statement from the makers of Deep Blue: “We’ve got one of the greatest concentrations of computing power ever focused on a single problem working here,” (src).