3DS is kinda like a PC if you upgraded it a bit. You'd have to buy a proper optical drive obviously, then some ram, a better CPU too I'd say and a motherboard to make it work, probably best be safe and pick up a GPU too. And you'll need a PSU to power all that. Hmmm, probably won't fit in the case now, so a new case. Did you say you have a monitor? Not sure the DS ones are compatible.