The History of PDP Nine

Ken Thompson ordered a game that he had written for the expensive G machine to some PDP seven. In doing the port, he ended up writing a lot of the IO code because it had this like, we disc set up with a vertical disc that would spin off if it spun too fast or whatever. And at some point he was like, Hey, I'm three weeks away from an operating system. He mentioned the operating system basically as additions to this game or the IO stuff to spot the game.