Broderick starred in a fairly popular movie called War Games in 1983 as a teenage hacker using a PC.
How was this movie so popular or even believable, if the internet and computers weren't ubiquitous? When did the PC get widely adopted? How would kids learn to program them if public schools weren't yet teaching computers? Were they considered just a novelty to buy your white middle class kid a PC?
There's a few incorrect statements in this.
The PC was widely known by 1983. The PC movement started in 1974 with the introduction of Altair computer. This was a kit computer that was available by mail order. It was not a very functional computer, but did give the basics of programming.
In 1977, Apple released the Apple II. Commodore released the Pet. Radio Shack released the TRS-80. All of these could be programmed with Basic. Peripherals increasing the capabilities of these computers were introduced rapidly to the Apple and TRS-80 lines.
There were a few computers introduced in this timeframe directly aimed for education. These were the AIM-65, Kim-1 and its follow up Sym-1.
Commodore made a significant move towards home users by the introduction of the Vic-20 in 1980 and the Commodore 64 in 1982. The Commodore 64 was sold in K-Marts. This sold 1 million units by 1984.
In terms of sales, the Apple II sold 64,000 units. The Apple II plus, which was released to market, sold 545,000 units by 1983.
The IBM PC 5150 was released in 1981 and was used widely in businesses.
I am skipping over how much of a wild-west environment the late 1970's and early 1980's were. There were dozens of manufacturers selling computers aimed at various niches. Osborne and Kaypro were aimed at portable computers (the precursor to laptops). Timex had its Sinclair computer. Coleco had its computers. Franklin made Apple clones.
There were large computer fairs in the late 1970's and early 1980's. There would be dozens of vendors and thousands of spectators. Comdex was an example of this. It had its first fair in 1979 in Las Vegas and had almost 4000 attendees. These were not limited to large cities. Marietta OH had a similar sized computer fair in 1982.
There were high school classes in various school systems by this time, but a lot of people were self-taught.
There were a number of computer networks at that time. ARPANET was the precursor to the Internet, but there were also other networks like UUCPNET, DECNET, and BITNET.
So, the movie war Games was actually fairly accurate for the hacking portions of the movie. The computer system depicted was a reasonable extrapolation of the computer systems publicly known and used at the time. The personal computer aspects were well within the known usage of the time.