by Daniel J. Horgan

This Date in IT History September

Sep 01, 20032 mins
Data Center

Grace Hopper’s Bug Discovery

1945 On Sept. 9, the Mark II computer system at the Computation Laboratory at Harvard University was on the fritz. The colossal calculator, which famously took up hundreds of cubic feet in the lab, was plagued by a mysterious glitch. When the team members, led by Grace Murray Hopper, a budding computer scientist from the U.S. Naval Reserve, open the computer for a closer look, they discover the first true computer bug.

Lodged between points in relay #70 in panel F was a 2-inch moth that had flown into the machine and caused the ruckus. While the term computer bug was part of computer users’ vocabulary before 1945, Hopper and her team are credited with the discovery of the world’s first computer bug and coin the phrase “debugging a computer program.” This legend even helped one young man become a millionaire. In March 2000, 25-year-old Joe Trela correctly answers “moth” to the final question (was it a moth, roach, fly or Japanese beetle that shorted out an early supercomputer?) on ABC’s Who Wants to Be a Millionaire to claim the $1 million grand prize.

Other Notable Events

3 The PowerPC chip arrives at Apple headquarters in 1992 and becomes the engine for the PowerMac, which releases in 1994.

6 The first plan for packet switching technology is proposed to ARPA in 1968 by a team of computer scientists at BBN. It later becomes ARPAnet and eventually the Internet.

8 “Electric Barbarella” by Duran Duran becomes the first single to be released online before hitting the stores in 1997. Music lovers flock neither the Internet nor the stores.

11 Kenneth Starr’s report on his investigation into the President Clinton and Monica Lewinsky affair is released online in 1998. Between 3,000 and 5,000 people attempt to download the report each minute.

12 Marc Andreessen introduces Netscape Navigator in 1994.

30 Microsoft Excel is released in 1985.

Sources:,,, U.S. Navy website, ABC News,, North County Times