lol actually calling it OBD0 is wrong.
it's really non OBD because it's not OBD at all!
it's just that so many guys started saying OBD0 it just took off as the term for non OBD

those of us that were master tech's in the dealerships back then went to school to learn about the new standardized OBD systems that the government made all the car manufactorers put into their cars at the time, but before OBD1 there wasnt any OBD at all. before OBD1 all cars' diagnostic systems were diff.. some had a readable data stream, some didnt, some had flashing engine lights for codes, and some didnt.
that's why big brother stepped in to create the "OBD" system, so all cars will have the same uniform type of diagnostic system with the same type of readable data stream when you hook up your scanner to them.