[ZirconiumX]

Of those cores, MIPS own the direct rights to none of them.

The R3051 (used in the PlayStation 1) was a derivative of the R3000A (which MIPS should have the rights to) made by IDT. I don't think MIPS have the right to the modifications.

The R4300 (A derivative, the NEC VR4300 was used in the Nintendo 64) was designed by Quantum Effect; I think whoever owns what's left of them would own the HDL, if it's still around.

The R5900 (used as the core of the PlayStation 2's Emotion Engine) was designed by Sony and Toshiba; I'm pretty sure Toshiba have the rights to it.

[pozzed420]

Yeah I know there's licensing issues for those exact processors, it would still be cool to see the stuff they were derived from.