I can't imagine how hard it must have been to estimate hardware specs at that time. Not only on raw performance, but also understanding details of the console architectures, special designed components and how they work as a whole. I've been researching a lot about the development process on old consoles, I love to see the creativity and techniques of the developers to make the best use of such limited resources. Today we take things like memory or processing power for granted, and while this makes devs lifes a hell of a lot easier, it also lacks of excitement in some way.