I first played Oregon Trail in 1977 – I was in 7th grade at the time. My math class had a 10 character per second teletype for us to log into the University of Minnesota mainframe. It was games like this that got me interested in programming. The text based version of Oregon Trail was written in basic… I was able to print out the code and study it. City Pages has a nice write up on the development by three Minnesotans back in 1971. Also a quick video documentary of the development of the game.