the FCC requirements, both new machines were built around cast aluminum shields forming a partial Faraday cage, with the various components screwed onto this internal framework. This resulted in a sturdy computer, at the disadvantage of added manufacturing expense and complexity.

The FCC ruling also made it difficult to have any sizable holes in the case, which would allow RF leakage. This eliminated expansion slots or cards that communicated with the outside world via their own connectors. Instead,