I've been able to get a lot of work done on the CPU. I'm not an assembly programmer. All of the programming I've ever done has been from a high language level, so it's interesting to see the actual instructions that the CPU offers. I've been able to spend the last few weeks implementing the instruction set. I've tried to be rigorous in testing, but the CPU itself isn't really all that functional. It only makes sense in context and right now I know nothing about that context. I've become pretty familiar with the 6502 instruction set, but know very little about how it's actually programmed. I have no idea how it actually places graphics on the screen or plays sound. I assume it involves placing information at some point in memory since that's pretty much all that the CPU instruction set does. I'm looking forward to implementing the screen and the PPU. That ought to be pretty interesting. Once I've done that I ought to be able to get the CPU to actually do something and will hopefully be able to start debugging. Right now I'm emulating the CPU, but have not started emulating the entire system.