http://glfwtfwhlsm2u5pw3b7crist7bt7fwepj2wgv3n3b64unj22v5435tyd.onion/blog/2019/11/05/Incarnations-of-modularity.html
I.e., there was a singleton for the robot, vision, for the motion, world model, debugger, feet(!), for every aspect of communication and so on.
In other words, at this stage of the software modularity was achieved through rigorous usage of singletons that could be (and were) accessed from all over the code.