Comment by Causality1
7 years ago
Not just back then. Nintendo has put a lot of wacky stuff in cartridges. Learn with Pokemon Typing Adventure had a bluetooth adapter in its cartridge to communicate with its bundled bluetooth keyboard. Some early NES games were actually Famicom boards with a 60 to 72 pin adapter embedded in the cartridge. Morita Shogi 64 had a modem and a phone jack built into its cartridge. Animal Crossing for N64 had a real-time clock. Mario Artist: Talent Studio had a cartridge that featured an entire composite video capture card. The Japanese version of Tetris 64 had a modified controller pak which connected to an infrared heartrate sensor for a special play mode that tested the user's ability to keep calm.
More examples: WarioWare: Twisted! for Game Boy Advance with a gyroscope sensor, and Boktai: The Sun Is in Your Hand (also for GBA) with a light sensor for detecting sunlight.
Pokemon: HeartGold/SoulSilver have an infrared comms port to communicate with the pokewalker, and to mystery gift - because the Game Boy Color had one!