1983 Film starring Mathew Broderick and Alley Sheedy. In the 80s computers were very new and their potential largely unknown to the public. The nerd generation was growing and these people were attaching themselves to computers and learning them well.
Who would have thought that back then a kid from nowhere could hack into a government site (Unknowingly) looking for the latest video games to play, then to trigger nuclear war between the Americans and the Russians. When the kid realizes it he must find a way to stop it.
Pretty well made movie for the time and still holds up today. Great casting choice and the visuals (ie the sets etc) were very good. I have watched it several times and will again.