Apple ][ and the onset of personal computing. With the rising tide of personal computing came games, and themed games representing sporting events were an aspect of electronic gaming. The 1980s started with the USA's boycott of the Olympic games in the USSR. Which then resulted in the USSR's boycott of the games in 1984 in Los Angeles. An interesting time, but the spirit of the Olympics was alive in the electronic competition of Olympic Decathlon.
The game, like many early computer games had some rudimentary input controls. For instance, for the foot race, you would alternately mash the 1 and 2 keys as fast as possible. If you were racing multiple people, they would also mash keys simultaneously, to see who could mash keys the fastest!
The game also used the Apple ][ paddles, which allowed for some analog input, but was rather horribly executed. Analog input was generally terrible until the computer joysticks became more popular, allowing developers to come to grips with how to effectively integrate analog input.
One of the most memorable parts of the game was the monophonic music during the opening crawl, roughly approximating the Olympic theme song Bugler's Dream.