JargonFile/entries/bug.txt

bug

n. An unwanted and unintended property of a program or piece of hardware,
esp. one that causes it to malfunction. Antonym of feature. Examples:
There's a bug in the editor: it writes things out backwards. The system
crashed because of a hardware bug. Fred is a winner, but he has a few bugs
(i.e., Fred is a good guy, but he has a few personality problems).
Historical note: Admiral Grace Hopper (an early computing pioneer better
known for inventing COBOL ) liked to tell a story in which a technician
solved a glitch in the Harvard Mark II machine by pulling an actual insect
out from between the contacts of one of its relays, and she subsequently
promulgated bug in its hackish sense as a joke about the incident (though,
as she was careful to admit, she was not there when it happened). For many
years the logbook associated with the incident and the actual bug in
question (a moth) sat in a display case at the Naval Surface Warfare Center
(NSWC). The entire story, with a picture of the logbook and the moth taped
into it, is recorded in the Annals of the History of Computing , Vol. 3, No.
3 (July 1981), pp. 285--286. The text of the log entry (from September 9,
1947), reads 1545 Relay #70 Panel F (moth) in relay. First actual case of
bug being found. This wording establishes that the term was already in use
at the time in its current specific sense and Hopper herself reports that
the term bug was regularly applied to problems in radar electronics during
WWII. The original bug (the caption date is incorrect) Indeed, the use of
bug to mean an industrial defect was already established in Thomas Edison's
time, and a more specific and rather modern use can be found in an
electrical handbook from 1896 ( Hawkin's New Catechism of Electricity ,
Theo. Audel Co.) which says: The term bug is used to a limited extent to
designate any fault or trouble in the connections or working of electric
apparatus. It further notes that the term is said to have originated in
quadruplex telegraphy and have been transferred to all electric apparatus.
The latter observation may explain a common folk etymology of the term; that
it came from telephone company usage, in which bugs in a telephone cable
were blamed for noisy lines. Though this derivation seems to be mistaken, it
may well be a distorted memory of a joke first current among telegraph
operators more than a century ago! Or perhaps not a joke. Historians of the
field inform us that the term bug was regularly used in the early days of
telegraphy to refer to a variety of semi-automatic telegraphy keyers that
would send a string of dots if you held them down. In fact, the Vibroplex
keyers (which were among the most common of this type) even had a graphic of
a beetle on them (and still do)! While the ability to send repeated dots
automatically was very useful for professional morse code operators, these
were also significantly trickier to use than the older manual keyers, and it
could take some practice to ensure one didn't introduce extraneous dots into
the code by holding the key down a fraction too long. In the hands of an
inexperienced operator, a Vibroplex bug on the line could mean that a lot of
garbled Morse would soon be coming your way. Further, the term bug has long
been used among radio technicians to describe a device that converts
electromagnetic field variations into acoustic signals. It is used to trace
radio interference and look for dangerous radio emissions. Radio community
usage derives from the roach-like shape of the first versions used by 19th
century physicists. The first versions consisted of a coil of wire (roach
body), with the two wire ends sticking out and bent back to nearly touch
forming a spark gap (roach antennae). The bug is to the radio technician
what the stethoscope is to the stereotypical medical doctor. This sense is
almost certainly ancestral to modern use of bug for a covert monitoring
device, but may also have contributed to the use of bug for the effects of
radio interference itself. Actually, use of bug in the general sense of a
disruptive event goes back to Shakespeare! (Henry VI, part III - Act V,
Scene II: King Edward: So, lie thou there. Die thou; and die our fear; For
Warwick was a bug that fear'd us all. ) In the first edition of Samuel
Johnson's dictionary one meaning of bug is A frightful object; a walking
spectre ; this is traced to bugbear , a Welsh term for a variety of
mythological monster which (to complete the circle) has recently been
reintroduced into the popular lexicon through fantasy role-playing games. In
any case, in jargon the word almost never refers to insects. Here is a
plausible conversation that never actually happened: There is a bug in this
ant farm! What do you mean? I don't see any ants in it. That's the bug. A
careful discussion of the etymological issues can be found in a paper by
Fred R. Shapiro, 1987, Entomology of the Computer Bug: History and Folklore
, American Speech 62(4):376-378. It helps to remember that this dates
from 1973. (The next cartoon in the Crunchly saga is 73-10-31. The
previous cartoon was 73-07-24.