"Some of them, yeah," said Roger. "The big mainframes, mostly- machines that take up whole rooms, that's how much space we need for all the parts to handle that kind of processing power. Robots usually can't- they're smaller machines, people-sized more or less, and mobile. They might use 'I' in conversation and they might have personalities, but most robots don't have the ability to do much outside of a set of rules and preprogrammed reactions. Takes a whole lot of expensive hardware and really sophisticated programming to bring a robot into the same league as a self-aware ZAX, at least from what I know of them."