For general exploringobjects requirement, narrow pulse signal with tens millimicro second to millimicrosecond has the frequency spectrum from DC to thousands MHz.
Floppy disks? You mean those flexible plastic computer disks used for storing data magnetically. Well, I can't believe the guys in The Pentagon are nostalgic about floppy disks.
It's not like we have some magic electromagnetic shrink ray, like professor Wayne Szalinski used in " Honey, I Shrunk the Kids" to shrink his children.
An EEG or an electroencephalogram, which I had to spend a few weeks practicing how to say is a bunch of electrodes that go into your scalp and it picks up the electromagnetic brain activity that comes from your head.
To get more into the specifics, according to the US Department of Energy, a GMD and the E3 waves of a HEMP are going to put similar equipment and technologies at risk.