Steve has been do some prototyping for his home-built Mac on an Xilinx Spartan 3A FPGA board:
I’ve never been so happy to see a Sad Mac! A boot failure may not seem very exciting, but I’m thrilled that it’s actually doing something recognizably Macintosh-like. That means it’s actually running 68000 code from the Mac ROM, which is drawing stuff to the screen buffer, which is getting read by the video module and displayed to the VGA screen. From here it will be a long, slow road of implementing replacements for the VIA, SCC, IWM, and other components.
It’s trying to play a sound, too, by streaming some data through the sound buffer. With some more work to pull bytes from that buffer at 22 KHz, I could hear the glorious boot beep!
FPGA Mac - [Link]