What control architecture was most popular in the 1970s?

The most popular control architecture in the 1970s was the Centralized Control System. This system was widely used in industries for process control. It consists of a single, central computer that controls the entire process. The central computer receives data from various sensors, processes it, and then sends commands to the actuators to control the process. This type of control architecture was popular due to its simplicity and cost-effectiveness. However, it has some disadvantages such as lack of flexibility and scalability, and vulnerability to single point of failure.