Topic summary
Famicom
Extracted from the Wikipedia article Nintendo Entertainment System.
Game Pak
Famicom cartridges are shaped slightly differently. Unlike NES games, official Famicom cartridges were produced in many colors of plastic. Adapters, similar in design to the popular accessory Game Genie, are available that allow Famicom games to be played on an NES. In Japan, several companies manufactured the cartridges for the Famicom. This allowed these companies to develop customized chips designed for specific purposes, such as superior sound and graphics.