The Innovators

[Grace Hopper's] crew helped popularize the terms bug and debugging. The Mark II version of the Harvard computer was in a building without window screens. One night the machine conked out, and the crew began looking for the problem. They found a moth with a wingspan of four inches that had gotten smashed in one of the electromechanical relays. It was retrieved and pasted into the log book with Scotch tape. "Panel F (moth) in relay," the entry noted. "First actual case of a bug being found." From then on, they referred to ferreting out glitches as "debugging the machine."