These animations looked pretty good for 1984.
Were they computer generated, or how were they produced?
Yes. These sequences were indeed computer-generated. As you can see from the video below, an extensive CGI sequence was created by the wizards at ILM
Some additional "hand-painting" was also used, but this was all digital as well and done on computer-aided art programs.
The 'rolling fire' effect is discussed in the Open University video below and was accomplished using compositing and matting to create a wall of over a hundred-thousand big fuzzy pixels