Can I change the battery without erasing the save RAM?
Well, you possibly can, but it’d really just be simpler to replace the battery and lose your saved game. Changing the battery in an NES game is not too difficult; it involves desoldering the original battery, replacing it with an identical type, and soldering that down. If you intend to replace the battery and keep your backup data, then you will need to figure out a way to keep a constant voltage applied to the save RAM throughout the entire replacement process. • What is the expansion port on the NES for? It was rarely used, though on the Famicom it was used for many things, such as the 3-D glasses, Keyboard, Tape Drive, etc. The NES had two accessories which used the expansion port: The Miracle Keyboard Piano Teaching System, and The Baton Teleplay System [a modem device for the NES which offered head-to-head play on the NES and Genesis]. Teleplay, however, was never widely released.
