The First Bug

Photo #: NH 96566-KN (Color)
The First “Computer Bug”
Moth found trapped between points at Relay # 70, Panel F, of the Mark II Aiken Relay Calculator while it was being tested at Harvard University, 9 September 1945. The operators affixed the moth to the computer log, with the entry: “First actual case of bug being found”. They put out the word that they had “debugged” the machine, thus introducing the term “debugging a computer program.”


In 1988, the log, with the moth still taped by the entry, was in the Naval Surface Warfare Center Computer Museum at Dahlgren, Virginia.
Courtesy of the Naval Surface Warfare Center, Dahlgren, VA., 1988.

U.S. Naval Historical Center Photograph.

Although the story of Grace Hopper’s moth here caught at Relay #70 has been attempted to be debunked, and also with folks out there who have pushed the fact that Thomas Edison used the word “bug” similarly but he certainly didn’t have a computer back then, I’m prone to loving the idea that Grace Hopper gave us this important word.

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