The Famicom Disk System was an early attempt at expanding the capability of the Famicom, which was the original Japanese version of the NES. This new add-on used discs rather than cartridges, which were cheaper to produce and held more data. Unfortunately the technology at the time was faulty; so much so that Nintendo of Japan continued servicing them until their patents expired in 2003. Interestingly enough, NES has an expansion port located on the bottom of the console. This is because Nintendo planned to release a version of the Famicom Disk System for international markets. This expansion port is absent on the original Famicom, and the Famicom Disk System connects to the Famicom by the cartridge slot. However, the international version of the Famicom Disk System never saw the light of day, and the NES expansion port went unused.