Magic smoke
From Wikipedia, the free encyclopedia
Magic smoke (also called factory smoke, mysterious blue smoke, blue smoke, or magic blue smoke of death) refers to smoke produced by malfunctioning electronic circuits. The origins of the magic smoke have become a running in-joke that started among electrical engineers and technicians before it was more recently adopted by computer programmers. The actual origin is the black plastic epoxy material that is used to package most common semiconductor devices such as transistors and integrated circuits. When it burns, it produces smoke that is blue in color.
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[edit] Joke
The magic smoke is observed to come out of electronic components when overheated, often through exposure to an extreme electrical current usually caused by the application of excess voltage through some failure of the circuit. According to the joke, at their factories, manufacturers put a little bit of magic smoke into every electronic component and it is this smoke which makes the device work. In support of this joke, once the magic smoke has been released, the device lacks its key component and no longer works. The smoke thus can be thought of as an essential part in the device's function. It is also noted that once let out, the magic smoke cannot be put back in.
In some variations of the joke, it is alleged that the major microchip production companies (especially the large microprocessor manufacturers) are involved in a conspiracy to keep the true nature of their products under wraps.[1]
[edit] Usage
This has led to use of the phrases (and variants of) "leaking smoke", "the magic smoke is escaping", or "you let the smoke out!" as a euphemism for the destruction of a processor, integrated circuit or other electronic component, by overheating.
When a device is powered on for the first time, it is often called a "smoke test".
The emblem of the Debian free software project is a swirl. Bruce Perens has claimed that the swirl represents magic smoke, although the logo's creator has never offered an official explanation and others have offered competing theories.[2],[3]
[edit] References
- ^ John R. Barnes (2004), Robust Electronic Design Reference Book, Springer, ISBN 1402077378, http://books.google.com/books?id=V2GIeUAZj0kC&pg=PT308&dq=%22Magic+smoke%22&ie=ISO-8859-1&output=html&sig=mu9toNIb0nR-jUZFZn1NhWRRrPs
- ^ "Raul never made an official statement about the meaning or symbolism of the logo..., so several theories have developed. ... Bruce Perens offers the following description: It's 'magic smoke'." Krafft, Martin F. (2005), The Debian System, No Starch Press, pp. 66, ISBN 9781593270698
- ^ The swirl has been designed by Raul M. Silva who won a contest organized in 1999 [1]
[edit] See also
[edit] External links
- Magic smoke entry in the Jargon File
- Magic smoke entry at FOLDOC
- Lucas Replacement Wiring Harness Smoke (for automotive electrics)
