Silver Spoons episode 1:7: The Great Computer Caper. Aired November 6, 1982.
Rick Schroder and Gary Coleman (in a Diff’rent Strokes crossover) hack the military. Clip.
I think that beings up a different question: When was the last time “Information Superhighway” used unironically?
It also showed him using a war dialer program to find other modems in an area code by dialing every phone number and noting which ones had modems.
re: Max Headroom (1985), they did ‘hack’ into systems, but as I recall, it was largely single television stations that were the dominant form of entertainment. I don’t know if they envisioned a ‘connected’ internet as such.
That said, it was set in the future so doesn’t meet the OP’s standard.
Great. Sounds like we have a winner. Thanks so much!
In real life, this January, 1994 Today Show clip is always worth a view.
In the related videos list from that classic Today show clip, there is this 1981 TV news report out of San Francisco that features Compuserve’s early service, though they don’t even mention them by name. Again though, not really the Internet or any of its predecessors though.
Note that in this clip, Rick refers to it as “visiting”. Was that a real term?
William Gibson of Neuromancer fame also wrote an X-Files episode, “Kill Switch,” which first aired February 15, 1998 and was about the Internet.
The previously mentioned X-Files third season episode “2Shy” aired November 3, 1995 had the monster-of-the-week meeting his victims in online chat rooms.