magic smoke

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magic smoke

(electronics, humour)
A substance trapped inside integrated circuit packages that enables them to function (also called "blue smoke"; this is similar to the archaic "phlogiston" hypothesis about combustion). Its existence is demonstrated by what happens when a chip burns up - the magic smoke gets let out, so it doesn't work any more.

See Electing a Pope, smoke test.

Usenetter Jay Maynard tells the following story:

"Once, while hacking on a dedicated Zilog Z80 system, I was testing code by blowing EPROMs and plugging them in the system, then seeing what happened. One time, I plugged one in backward. I only discovered that *after* I realised that Intel didn't put power-on lights under the quartz windows on the tops of their EPROMs - the die was glowing white-hot. Amazingly, the EPROM worked fine after I erased it, filled it full of zeros, then erased it again. For all I know, it's still in service. Of course, this is because the magic smoke didn't get let out."

Compare the original phrasing of Murphy's Law.
References in periodicals archive ?
They witnessed a spectacular triple pirouette as the ships turned to return down river, and the nine jets of the Red Arrows flashed overhead trailing red, white and blue smoke.
Two of the wildly popular Shake Shack restaurants are part of the portfolio as well as Danny Meyer's Blue Smoke on the Road, and The Palm Restaurant.
It'll belch blue smoke until that oil you squirted in there is burned up, but that should clear up in minutes.
Stewards at Palmerston Park in Dumfries moved in to the Rangers end when blue smoke was seen and quickly dealt with the flare.
The team's display mixes nine-ship formations with thrilling synchro manoeuvres, all of which involve their patriotic red, white and blue smoke.
and tell us how you make your Yorkshires rise Never measure my mixture, always use lard and heat until blue smoke comes from the tins, very hot oven, never wash your tins just wipe clean and do not open the oven door for the first 15 minutes after you put them in.
Delta is partnering with Blue Smoke chef Jean-Paul Bourgeois, while KLM has enlisted chef Richard van Oostenbrugge of Amsterdam's Hotel De L'Europe.
The US star, whose new album Blue Smoke - The Best Of, is out now, met Carl when she was 18.
SOARING high above the Tyne Bridge with red, white and blue smoke billowing behind, this is the incredible view from the cockpit of a Red Arrow visiting the Great North Run.
You just don't see many old bangers rumbling down the road belching out blue smoke these days.
The 100,000-plus people who were thought to have flocked to see her sang along to hits including Jolene and Blue Smoke.
Showcasing the diversity of country star Dolly Parton, Blue Smoke spans the full country gamut.