[cmrdporcupine]

6502 is about as simple a CPU as you can get without it being a complete pain in the ass to work with. So it's a great CPU to learn nuts and bolts of computer hardware. It's pretty easy to interface it to external devices, pretty easy to learn the instruction set, there's a huge community of enthusiasts for it, it's very cycle efficient and very responsive to interrupts and somehow feels fast, and the ins and outs of how it functions are super well documented and reverse engineered.