Even funnier, the 'games' were as much software than hardware extension. The main system was often designed to have an external loop to hook in optional chips in the cartridge.
Yep. As i recall this was the case for both NES and SNES, with SNES making a bigger marketing fuss about it (SuperFX mostly). I think they stepped away from direct bundling with the N64 and dropped the concept when moving to discs with the Gamecube.
