I don't think they came out later. They existed in the spec from the beginning and some very early long movies were a single disc (e.g., Titanic). Some movies s

I don't think they came out later. They existed in the spec from the beginning and some very early long movies were a single disc (e.g., Titanic). Some movies still needed flipping or two discs, like Gone with the Wind but it's just too long.