Douglas Rain, HAL 9000's voice in '2001: A Space Odyssey,' has died. He was 90.

Im sorry, Dave, Im afraid I cant do that.

Douglas Rain, the actor who performed the voice of the computer Hal 9000 in Stanley Kubrick's film '2001: A Space Odyssey,' has died. He was 90 years old.

"Dave, this conversation can serve no purpose anymore. Goodbye." Douglas Rain, 13 March, 1928 - 11 November, 2018. #HAL9000 pic.twitter.com/p742YU7VdT

— Stanley Kubrick (@StanleyKubrick) November 12, 2018

A transcript of the '2001' voice recording session in the Stanley Kubrick archives at the University of the Arts, London shows that Kubrick didn't give much direction to Rain, just a few brief notes like this:

Sound a little more like its a peculiar request.

A little more concerned.

Just try it closer and more depressed.

From an archival New York Times article about the story that led to Rain being cast as the computer's voice in '2001' ---

The 2001 historian David Larson said that Kubrick came up with the final HAL voice very late in the process. It was determined during 2001 planning that in the future the large majority of computer command and communication inputs would be via voice, rather than via typewriter.

But artificial intelligence was decades from a convincing facsimile of a human voice and who was to say how a computer should sound anyway?

To play HAL, Kubrick settled on Martin Balsam, who had won the best supporting actor Oscar for A Thousand Clowns. Perhaps there was a satisfying echo that appealed to Kubrick both were from the Bronx and sounded like it.