Hardware bug
A hardware bug is a defect in the design, manufacture, or operation of computer hardware that causes incorrect operation. It is the counterpart of software bugs which refer to flaws in the code which operates computers, and is the original context in which "bug" was used to refer to such flaws. Intermediate between hardware and software are microcode and firmware which may also have such defects. In common usage, a bug is subtly different from a "glitch" which may be more transient than fundamental, and somewhat different from a "quirk" which may be considered useful or intrinsic.
History
The Middle English word bugge is the basis for the terms "bugbear" and "bugaboo" as terms used for a monster.[1]
The term "bug" to describe defects has been a part of engineering jargon since the 1870s and predates electronic computers and computer software; it may have originally been used in hardware engineering to describe mechanical malfunctions. For instance, Thomas Edison wrote the following words in a letter to an associate in 1878:
It has been just so in all of my inventions. The first step is an intuition, and comes with a burst, then difficulties arise—this thing gives out and [it is] then that "Bugs"—as such little faults and difficulties are called—show themselves and months of intense watching, study and labor are requisite before commercial success or failure is certainly reached.[2]
Baffle Ball, the first mechanical pinball game, was advertised as being "free of bugs" in 1931.[3] Problems with military gear during World War II were referred to as bugs (or glitches).[4] In the 1940 film, Flight Command, a defect in a piece of direction-finding gear is called a "bug". In a book published in 1942, Louise Dickinson Rich, speaking of a powered ice cutting machine, said, "Ice sawing was suspended until the creator could be brought in to take the bugs out of his darling."[5]
Isaac Asimov used the term "bug" to relate to issues with a robot in his short story "Catch That Rabbit", published in 1944.
The term "bug" was used in an account by computer pioneer Grace Hopper, who publicized the cause of a malfunction in an early electromechanical computer.[6] A typical version of the story is:
In 1946, when Hopper was released from active duty, she joined the Harvard Faculty at the Computation Laboratory where she continued her work on the Mark II and Mark III. Operators traced an error in the Mark II to a moth trapped in a relay, coining the term bug. This bug was carefully removed and taped to the log book. Stemming from the first bug, today we call errors or glitches in a program a bug.[7]
Hopper did not find the bug, as she readily acknowledged. The date in the log book was September 9, 1947.[8][9][10] The operators who found it, including William "Bill" Burke, later of the Naval Weapons Laboratory, Dahlgren, Virginia,[11] were familiar with the engineering term and amusedly kept the insect with the notation "First actual case of bug being found." Hopper loved to recount the story.[12] This log book, complete with attached moth, is part of the collection of the Smithsonian National Museum of American History.[9]
Unintended operation
Sometimes users take advantage of the unintended or undocumented operation of hardware to serve some purpose, in which case a flaw may be considered a feature. This gives rise to the often ironically employed acronym INABIAF, "It's Not A Bug It's A Feature".[13] For example, undocumented instructions, known as illegal opcodes, on the MOS Technology 6510 of the Commodore 64 and MOS Technology 6502 of the Apple II computers are sometimes utilized. Similarly programmers (notably game and demo) on the Commodore Amiga took advantage of the unintended operation of its coprocessors to produce new effects or optimizations.
Security vulnerabilities
Some flaws in hardware may lead to security vulnerabilities where memory protection or other features fail to work properly. Starting in 2017 a series of security vulnerabilities were found in the implementations of speculative execution on common processor architectures that allowed a violation of privilege level.
In 2019 researchers discovered that a manufacturer debugging mode, known as VISA, had an undocumented feature on Intel Platform Controller Hubs, known as chipsets, which made the mode accessible with a normal motherboard possibly leading to a security vulnerability.[14]
Pentium bugs
The Intel Pentium series of CPUs had two well-known bugs discovered after it was brought to market, the FDIV bug affecting floating point division which resulted in a recall in 1994, and the F00F bug discovered in 1997 which causes the processor to stop operating until rebooted.
References
- Computerworld staff (September 3, 2011). "Moth in the machine: Debugging the origins of 'bug'". Computerworld. Archived from the original on August 25, 2015.
- Edison to Puskas, 13 November 1878, Edison papers, Edison National Laboratory, U.S. National Park Service, West Orange, N.J., cited in Hughes, Thomas Parke (1989). American Genesis: A Century of Invention and Technological Enthusiasm, 1870-1970. Penguin Books. p. 75. ISBN 978-0-14-009741-2.
- "Baffle Ball". Internet Pinball Database.
(See image of advertisement in reference entry)
- "Modern Aircraft Carriers are Result of 20 Years of Smart Experimentation". Life. June 29, 1942. p. 25. Archived from the original on June 4, 2013. Retrieved November 17, 2011.
- Dickinson Rich, Louise (1942), We Took to the Woods, JB Lippincott Co, p. 93, LCCN 42024308, OCLC 405243, archived from the original on March 16, 2017.
- FCAT NRT Test, Harcourt, March 18, 2008
- "Danis, Sharron Ann: "Rear Admiral Grace Murray Hopper"". ei.cs.vt.edu. February 16, 1997. Retrieved January 31, 2010.
- "Bug Archived March 23, 2017, at the Wayback Machine", The Jargon File, ver. 4.4.7. Retrieved June 3, 2010.
- "Log Book With Computer Bug Archived March 23, 2017, at the Wayback Machine", National Museum of American History, Smithsonian Institution.
- "The First "Computer Bug", Naval Historical Center. But note the Harvard Mark II computer was not complete until the summer of 1947.
- IEEE Annals of the History of Computing, Vol 22 Issue 1, 2000
- James S. Huggins. "First Computer Bug". Jamesshuggins.com. Archived from the original on August 16, 2000. Retrieved September 24, 2012.
- Nicholas Carr. "'IT'S NOT A BUG, IT'S A FEATURE.' TRITE—OR JUST RIGHT?". Wired.
- Lucian Armasu. "Intel Chipsets' Undocumented Feature Can Help Hackers Steal Data". Tom's Hardware.