In the mid 90s I had the dubious pleasure of being asked to repair a series of TEMPEST certified computers: standard Zenith 8086 clones (well, as standard as a

In the mid 90s I had the dubious pleasure of being asked to repair a series of TEMPEST certified computers: standard Zenith 8086 clones (well, as standard as a Zenith got anyway) inside a massive steel chassis with all inputs/outputs wrapped around multiple ferrite cores before passing through some heavy-duty milspec connectors. Took a solid couple of minutes each machine pulling screws just to get the lid off so I could plug in a keyboard and monitor (Hercules Monochrome!) and assess the system. Took a dozen machines and made four or five working ones - lot of hard drive failures though Spinrite did manage to resurrect a couple. Still remember all those little jumper leads going from the peripheral cards through the ferrites and into the funky round connectors on the outside of the box.