[sireat]

1993 had the John von Neumann affair (I played in 1994 World Open so missed out on the fun) where the player had huge dreadlocks, presumably hiding headphones.

"At the World Open 1993 in Philadelphia a completely unknown player appeared, unsubtly calling himself John von Neumann. He played excellently, drawing against GM Helgi Olafsson in the second round. But in round four he suddenly stopped at move nine and lost on time."

"Von Neumann won a prize in the category of players without an Elo rating. Naturally people had become suspicious of this unknown and highly unorthodox player. Before the organisers handed over the $800 check they asked him to solve a simple chess puzzle. He refused, turned and left, and has never been seen again at chess tournaments"

Who was he and who was his assistant? Personal computers were not quite at the GM level in 1993.

https://en.chessbase.com/post/a-history-of-cheating-in-che-2