Someone made a
TMS9918 clone on an FPGA. TMS9918 is the VDP in the ColecoVision, MSX, and TI-99/4A. The nearly pixel-perfect port of Donkey Kong to the ColecoVision
inspired Nintendo to work on its own console. I wonder how hard it'd be to make an open source clone of the NES PPU and put it on opencores.
Considering Kevtris did it twice...I figure it's probably not much harder than say implementing a 6502 in verilog. (However the exact timing might be a bit of a B****)
TMS9918 on an FPGA is not that big deal, considering One Chip MSX (a FPGA-based MSX clone) was released in 2006, and it implements a loaded MSX2 even.
Yeah it's kinda cool that someone made that, but for me there's no way I'd pay the $100 it costs. I'd save up for Kevtris' clone that includes that chip and others, and wouldn't cost all that much more for what you get. Putting in a system needs a longer reset delay, from reading the thread about it, apparently with a Coleco (what I would use it with, I have a TI99 but doubt I'll ever fire it up), you have to reset the system manually after powering it up.
And actually someone already posted source for the FPGA NES, in VHDL. I forget the name, a Japanese guy I think it was. I think he used a 6502 from the opencores site. Who knows if it's accurate (the ROM was loaded into block RAM of the FPGA, so I guess running anything besides NROM was out of the question). But open source FPGA stuff is practically useless unless you really know what your doing (enough to make your own custom boards).