Jack Ganssle is an embedded guru and also a really neat guy. He collects real life disasters - when products behave Not As Intended. Some are pretty sad when they involve loss of life, but others are funny - like this store sign that reports a temperature of 501 °F. Whew!

When I pitched the concept of individual product disaster mysteries like “Law and Order” or “CSI” for my book, he liked the idea. And I was even more psyched that he would dig through his collection to find Real Life Disasters with similar root causes to the bugs in each of my chapters.

So I thought of Jack when I ran across a post about errors at a site called “The Daily WTF.” (Man I like that name!)

Check out these pics of other interesting Bugs in Public at - There’s Gotta Be A Catch.

And the Walgreens bug? It’s still out there - a student of mine sent me a picture he took of it in mid 2008.

And what caused the bug?  The bias current to an unconnected processor input in the electronic billboard changed; the normal “zero” state drifted to a logic “one.”  Firmware didn’t ignore this unused bit, and accepted the unnecessary and incorrect new data, generating a temperature display that was insane. - From Jack