Sony and Nintendo originally partnered to develop a CD-ROM attachment for the Super Nintendo, but later parted ways. In 1991, Sony introduced their own game console, the PlayStation, which was based on the modified Super Disc technology. The PlayStation was highly successful, selling over 300,000 units in its first month in Japan. By 2003, the original PlayStation had sold over 100 million units worldwide, establishing Sony as a major player in the video game industry.