[GOPJ]

And this would "wipe clean" computer chips covering how many miles? Would cars work without chips? Would airplanes fall out of the sky without chips? Nuclear power plants without control chips? Every Y2K nightmare in an instant?

A nightmare scenario would be a hostile nuke exploded aboard a plane by means of a carefully adjusted barometric detonator rigged to go off on

[Johnny B.]

And this would "wipe clean" computer chips covering how many miles? Would cars work without chips? Would airplanes fall out of the sky without chips? Nuclear power plants without control chips? Every Y2K nightmare in an instant?

My understanding is that you have to get the explosion much higher than airplane height before you'll get an EMP. Also, you need a big bomb, and it will only affect an area within line-of-sight. See here for a more detailed description.