Computer programmer Grace Murray Hopper wrote the following in her operations logbook Sept. 9, 1947, “Relay #70 Panel F (moth) in relay.”
She had just finished tracing out a problem with electrical current flowing through a circuit on an IBM Mark II electromechanical computer, owned by the US Navy.
Hopper discovered the peculiar cause of the current-flow interruption between the metal conducting points on one electromagnetic mechanical relay.
The disruption was a moth, which had somehow become stuck in the relay.
She removed the moth, taped it on a page in her logbook and wrote, “First actual case of bug being found.”
Hopper has since laid claim to the commonly used phrase, “a bug in the computer.”
We celebrate the 70th anniversary of the first real bug being found in a computer Saturday, Sept. 9.
I still haven’t decided exactly how I will be celebrating this historical event.
For the last 70 years, folks have been debating whether a moth should be considered a bug or an insect.
One encyclopedia says moths are in the butterfly family; belonging to the order of Lepidoptera, which are nocturnal flying insects.
I remember from 10th grade biology class; insects are in the Insecta group, and bugs belong in the Hemiptera order.
After 70 years, we are too used to saying, “I found a bug in my computer,” rather than, “I found an insect in my computer,” which I admit, does sound a bit odd.
Hopper’s opened logbook page (with the moth still taped to it) is kept in the History of American Technology Museum of the Smithsonian in Washington, DC. You can see this page at http://s.si.edu/2gGCS7X.
A photo of her working on the IBM Mark I computer can be seen at http://bit.ly/2xOsnHG.
Hopper was also involved in the development of the Universal Automatic Computer (UNIVAC), which was the world’s first commercially-used computer.
Grace Murray Hopper was born Dec. 9, 1906, in New York City, NY, and died Jan. 1, 1992, and is buried in Arlington National Cemetery in Virginia.
Of course, there are very few of the old-fashioned electromechanical relays being used these days.
However, more than 30 years ago, this columnist worked with them on a regular basis.
From 1960 until the end of 1986, the telephone company I worked for in Winsted provided dial telephone service using a GTE-Leich Electric TPS (terminal per station) electromechanical relay telephone switching system.
Perhaps you recall touring through the telephone company’s central office as part of a class trip when you were in school.
The telephone central switching office was filled with rows of 11-foot-high-by-4-foot-wide bay equipment frames containing hundreds of vertical 3-foot-tall-by-4-inch-deep-by-3-inch-wide electromechanical relay bars.
Many of these bars were equipped with up to 20 individual electromechanical relays, and were protected by clear, solid-plastic metal-framed covers.
Inside the telephone central office, one could determine how busy the call processing was by the sound of the relay’s clicking.
We never found any moths between the relays, but over time, a carbon-like oxidation would build up on the relay contact points; acting as an insulating agent, and thus preventing electrical current flow.
To remove this oxidation, we used a burnishing tool with a very fine sandpaper-like abrasive on a thin metal strip.
While moving the burnishing tool in a back-and-forth, filing-like motion, we would lightly sand off the oxidation (not the metal) on the contacts of the relays and switching components.
Dust also caused interference with a relay’s operation.
Part of our central office preventive maintenance included scheduled dust-removal cleaning of individual relay bars.
Outside (usually on the sidewalk in front of the telephone office), we’d blow the dust off the relays using high-pressured air from a spray hose connected to a portable air-generator.
Here’s hoping you’ll find no bugs in your computer, mechanical relays, and especially in your bed.
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