Inside the system? In the movie only ref is the 'real world' of the bots or the end of movie where Neo sees the walls as matrix filled text making the 'walls' of the world. What are you looking for? There is the matrix comics from the movie web site, there is a matrix book that has pictures of bots, concept art, and storyboards. Maybe in movie 2, or 3 you'll get more 'whats in the system' but as far as ref materials what ya see in the movie is about it.