Not true, most MICRO-Computers were designed for the difficult to achieve "Class A" or suitable for home use designation.
Monsters like Mainframes never needed to worry about the FCC because the ones that weren't built to survive a nuclear war were installed in purpose-built rooms or even sections of Industrial/Office space and the bomb shelter/room/building itself WAS the RFI as well as EMP shielding in some cases. (pun unintended, but left in just for the h%#1 of it!)
Only when MINI-Computers became more common the line blurred somewhat and RFI/FCC issues became more commonplace.
When the MicroComputer became ubiquitous, much to IBM's chagrin, BTW, A "Class A" rating became a MUST for any successful/marketable computer, even in many business settings.
IIRC, of course.
jt :b&w: