This is a very interesting 68kMLA thread on reverse engineering the Macintosh SE main logic board and custom chips. And… now I’ve made myself also become a key contributor!
20200802/https://68kmla.org/forums/index.php?app=forums&module=forums&controller=topic&id=60059&page=5&app=forums&module=forums&id=60059
So, how do we start out? We need to obtain scans of the main logic board, depopulated of all discrete components. Indeed, this is bringing to full fruition an idea I had before about reverse engineering existing electronics. But, the means and methods go even further than that. How do you do this with internal layer printed circuit boards? The approach is, well, quite clever, though it involves brute force. In general, you actually can’t shine bright light at a PCB and hope to see shadows of the internal layers. However, you can take a grinder to the surface to grind away the top layers. The internal layers will then be visible and you can scan them accordingly. Yes, unfortunately, it is a destructive process, so you really do need spare copies on hand unless you think you can get it right the first time!
Commodore 64 on an FPGA? Yes, it’s happened. Ultimate 64 Elite is the name of the game. Look here.
20200802/https://ultimate64.com/Ultimate-64-Elite