The specs have been well-known for many years. Clear back in 1988, my then-employer[1] had a TEMPEST-grade
version of their product.  It sold decently, for a while (owing to requirements on DoD contracts), until
"TEMPEST rooms" caught on, pretty much wiping out the market for the majority of TEMPEST-rated equipment.
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[1] They manufactured and supported "media conversion" systems, used to convert word processor and photo-
    typesetter documents, on floppy disk, from one format to another.  Not exactly a booming business,
    any more: they finally threw in the towel a few years ago; but for a time, their equipment was wide-
    ly used in the printing and publishing industries.  That's where I met the weird, Vydec-type 8" hard-
    sectored floppies that I mention, from time to time, as an example of technology that never quite
    made it to "prime time".

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HadEnuf?