I've got the ROM and RAM mounted in the address space. When the CPU starts, it zooms off doing something, but then gets stuck at a specific address. Maybe it's halting?
The next step is to add a single-step functionality - that will let me walk through the Space Invaders code listing one instruction at a time and make sure the CPU is actually working properly.
The DE-10 Nano has little user push buttons. Originally I was going to use those for insert coin and player 1 start, but we can multiplex their meaning based on how the user switches are set.