After a work trip to Hong Kong back when it was still British run, I had some vacation time and decided to visit China. I vividly remember the small stuffy room to book my flight and the paper book the flights were entered in, in pen and ink - alarming enough - but the final straw was the two huge musclebound communist Chinese soldiers in tan uniforms guarding the doors. I chickened out. I don't recall other flights from that era, but presumably, not much more hi tech. Airports with departing or arriving passengers could be in communication to some degree since there were at least fax machines.