When I started working as a junior secretary at the Inter.Continental Hotel Berlin in 1979 our telephone operator still had a device in front of her like Lily Tomlin had as Ernestine the phone lady - plug and connect.
Our reservation system was manual and one long wall was holding a board with slots for every room, I think or maybe every day. I am not sure as I did not work in that department, but I remember seeing that huge board when I had to use the telex machine (to book a comp reservation at another IC hotel).
However, our typewriters were modern electric IBM machines. Yet we still had to use carbon paper and make several copies for different files.
Oh, and we all smoked at our desks. Don't see that anymore.