According to Siliconera.com (linked above), Sony Japan has officially filed a patent for an adapter to make PS3 backwards compatible with PlayStation 2 titles.
To quote on the PS2 to PS3 adapter patent: "Japanese message boards are buzzing about a patent filed by Sony Computer Entertainment Japan for a new generation to previous generation console adapter.
We checked the Japanese Patent database to verify and a patent indeed exists.
A schematic of the proposed adapter (200) shows the device has its own processor, a DVD decoder/emulator, sound processor, and graphic processor."
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