Apple included ROM slots in most computers for a long time because they were leery of having another "Dirty ROM" fiasco on their hands. Connectix found a way to clean up the dirty ROMs in software and patented it, so Apple wound up paying them "an undisclosed amount" to buy and distribute MODE-32 as a freeware fix, barely avoiding a major class action suit.

With easily upgradeable ROM Slots and jumper or automatic cutouts for MoBo ROMs, they rested a bit easier. At the end of the Quadra era, the Slots remained in the spec/PCB Layout, but were usually left unimplemented. Later they were dropped entirely or used exclusively, depending upon the model.