HAL, the supercomputer of 2001: A Space Odyssey fame, talks about the making of the film in a reasonably frank interview at Mother Jones.
That’s easy. Trying to learn the dialogue. I was supposed to say this line: “I’ve just picked up a fault in the AE35 unit. It’s going to go 100 percent failure in 72 hours.” I just kept screwing it up: “A3E5 unit,” “A53E unit.” I mixed it up every way you can imagine. Keir Dullea, who was a good friend of mine, was laughing so hard he popped a blood vessel in his eye. Eventually they had to unplug me and let me cool down for a few minutes. When they booted me back up, I nailed the line.
