Keir Dullea

Dave: "Hello, HAL. Do you read me, HAL?"
HAL: "Affirmative, Dave. I read you."
Dave: "Open the pod bay doors, HAL."
HAL: "I'm sorry, Dave. I'm afraid I can't do that."
Dave: "What's the problem?"
HAL: "I think you know what the problem is just as well as I do."
Dave: "What are you talking about, HAL?"
HAL: "This mission is too important for me to allow you to jeopardize it."
Dave: "I don't know what you're talking about, HAL."
HAL: "I know that you and Frank were planning to disconnect me, and I'm afraid that's something I cannot allow to happen."

Dave: "HAL, I won't argue with you anymore! Open the doors!"
HAL: "Dave, this conversation can serve no purpose anymore. Goodbye."

Dave: "You know of course though he's right about the 9000 series having a perfect operational record. They do."
Frank: "Unfortunately that sounds a little like famous last words."

Frank: "What the hell could we do?"
Dave: "Well we wouldn't have too many alternatives."
Frank: "I don't think we'd have any alternatives. There isn't a single aspect of ship operations that isn't under his control. If he were proven to be malfunctioning I wouldn't see how we'd have any choice but disconnection."
Dave: "I'm afraid I agree with you."