9th September 1947: Moth ‘bug’ discovered inside a Harvard computer

On the 9th September 1947, the first computer ‘bug’ was found in the Harvard Mark II  electromechanical computer. In this case, the bug was a moth trapped between the points inside an electromagnetic relay. Its presence led to problems in the functioning of the whole computer which were resolved when the moth was removed. Development of the Harvard Mark II was financed by the United States Navy, which explains the involvement of Grace ‘Amazing Grace’ Hopper. She had previously been assigned t...