magic smoke

(redirected from Blue 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 classic literature ?
At lengthened intervals a log cabin, with its little space of cleared land about it, nestles under a rising ground, and sends its thread of blue smoke curling up into the sky.
It is well," said Mohammed Beyd, blowing a little puff of blue smoke straight out before him.
Morison selected a cigarette from his crested case, lighted it, blew a thin line of blue smoke toward the moon, and smiled.
The Prince, as he lounged in his wicker chair and watched the blue smoke of his cigarette curl upwards, looked more like an Italian--perhaps a Spaniard.
Fentolin had lit a cigarette and was watching the blue smoke curl upwards to the ceiling.
On the hill-top above me sat the rising moon; pale yet as a cloud, but brightening momentarily, she looked over Hay, which, half lost in trees, sent up a blue smoke from its few chimneys: it was yet a mile distant, but in the absolute hush I could hear plainly its thin murmurs of life.
As usual, the Red Arrows Display Team performed at the event's finale, spewing red, white and blue smoke into the air.
Especially O2T blue smoke detector is designed to reduce false alarms events and is considered as most suited to use in I.
The brand "TNT Red, White, Blue Smoke fireworks" (https://www.
But it was the headliners who once again stole the show, with the Red Arrows leaving their iconic red, white and blue smoke trails across the Swansea sky.
The Salt Lick BBQ, Blue Smoke, Jim 'N Nick's BBQ and Martin's Bar-B-Que Joint.
Caption: THE TIMBERLINE 850 USES CONVECTION TO EVENLY CIRCULATE BLUE SMOKE FOR THE BEST WOODFIRED FLAVOR