It is a good movie to watch if you are too young to see it when it came out. David Lightman hacks on his Altair 8800 computer, his grades at high school, and war dials until he finds Protovision's BBS instead, and he finds a mysterious computer prompt that asks for a Password. If you get it wrong, it hangs up on you. Little does he know it is the WOPR federal government computer that uses an AI program to chat with him after he guesses the right password.
Probably the movie that made me want to get into computers. Dated tech but modern ideas like a computer using its own “supervised learning” to learn a lesson about tic-toe-toe and nuclear war.