The character John Titor from "Steins gate", was actually based on a real person on the internet claiming to be a time traveler from the year 2036. He called himself John Titor and needed an IBM 5100 from the year 1975. Also, there's this interesting tidbit about that specifically.
"Every layer of Titor's story was there for a reason, including his seemingly contrived mission statement: though it might sound silly that scientists in the year 2036 would have any interest in collecting an antique IBM computer, the Minnesota newspaper Post Bulletin pointed out that Titor's explanation was based on facts. Basically, Titor's claim was that programmers in the future needed the old computer because it had a function that would give them access to a secret "memory code." Post Bulletin writer Patrick Stephenson interviewed one of the engineers of the original IBM 5100, Bob Dubke, who confirmed that this function existed. Crazy, right?"
https://www.grunge.com/98398/untold-truth-time-traveler-john-titor/