Nintendo had also begun development on a CD-ROM attachment for the SNES/Super Famicom. Their first partner in this project was Sony, whom Nintendo had worked with before to provide the SNES with its SPC sound chip. Development on the Nintendo PlayStation CD-ROM add-on and SNES/SFC standalone hybrid console began. However, at the last minute Nintendo decided to pull out of the partnership and instead go with Philips, and while no CD-ROM add-on was produced, several Nintendo properties (namely "The Legend of Zelda") appeared on the Philips CD-i media console. Upon learning this, Sony decided to continue developing the technology they had into the PlayStation. The exact reason Nintendo left its partnership with Sony has been the subject of speculation over the years, but the most common theory is that Sony either wanted too much of the profits for the machine or the rights to the CD-ROM attachment itself.