Mode 7 is a feature of the SNES's basic video hardware, not a cartridge add on. Most cartridges are just ROM, perhaps some battery backed RAM, and if needed so

Mode 7 is a feature of the SNES's basic video hardware, not a cartridge add on. Most cartridges are just ROM, perhaps some battery backed RAM, and if needed some bank switching / address decoding logic to glue things together. Nothing particularly smart. Certainly no extra processors running the show. All the smarts was in the console. There are exceptions, like the SNES games with coprocessors, but not all of them are full CPUs, and even then there are 1500+ SNES titles in total, and less than 100 with extra chips in them[1]. The mapper chips in NES games often did a bit more than just bank switching, but they weren't in control either. Cue someone mentioning the MB Microvision... [1] Based on Wikipedia, and I hope I roughly counted the number of entries in the coprocessor game table correctly.