Yup...I've seen plenty of Zeniths (i386 & i486 models) in Faraday cages. For that matter, I've seen a bunch of MacIIfx decked out similarly. Tempest rated boxes. My first job was with a shop (SecureWare) that did high security versions of Unix for these things. SCO-based for the Zeniths & A/UX-based for the Macs. The Unix was refered to as CMW (Compartmented Mode Workstation), was validated as a B1-level system (in Orange Book speak), and featured a secure window manager based on X (windows have security labels, and you couldn't do things like cut and paste between windows with different security labels). Pretty kewl, if you are into that sort of thing. Ken