See Visually Graphic Bugs and Enjoy!

[anorlunda]

Most software bugs are so obscure, that only the person who fixes the bug truly understands what went wrong and why. I love this video because it makes bugs marvelously visible.

I can almost imagine the lines of incorrect code, or the unstated incorrect assumptions, or the failures to foresee interactions while watching it. The video may be enjoyable to programmers and non programmers alike.

 

[berkeman]

Oops!

 

[berkeman]

Nowhere near as graphic or physically destructive, but this is the display on a credit card reader add-on that was recently placed on some of the vending machines in our kitchen area at work. A couple weeks after they were installed on the vending machines, a few of them ended up with scrambled displays (no, we are not in Japan). Would you trust a credit card reader to work for you with a display like that?

 

[Asymptotic]

Not a coding bug per se, but a "Digitape" with 2 micron resolution and electronics module that emulated quadrature encoder output was used to shuttle a half ton mold base between two work place positions (~ 1.5 seconds per move) with a linear servo. The electronics module had an array of DIP switches to set operational parameters, and the manufacturer had reversed operation of the increment/decrement 'direction' switch from the original to newer hardware revisions.

Didn't know that. The first time it came for the module to be replaced (and after carefully checking DIP switch positions were identical between the pull and new module) the machine was powered up. On the first 'move' command it promptly shot the (fortunately, toolless) permanent magnet table through a Lexan safety window, across a (fortunately, unoccupied) aisle where it came to rest halfway penetrating an adjacent concrete block wall.