HAL (Heuristically programmed ALgorithmic computer) is an artificial intelligence which interacts with the crew, usually represented only as a red television camera “eye” that can be seen throughout Discovery. He speaks in a soft voice and a conversational manner, in contrast to the ship’s crew who speak in a terse way, with little inflection. The voice of HAL 9000 was portrayed by Canadian actor Douglas Rain.
HAL in 2001: A Space Odyssey
HAL became operational in Urbana, Illinois at the HAL Plant at the University of Illinois, where the ILLIAC computers were assembled. The film states that this occurred in 1992, while the book gives 1997 as HAL’s birthyear. In 2001: A Space Odyssey, HAL begins to malfunction in subtle ways, and as a result, the decision is made to shut HAL down in order to prevent more serious malfunctions. The sequence of events and manner in which HAL is shut down differs between the novel and film versions of the story.
In the film, astronauts David Bowman and Frank Poole consider disconnecting HAL’s cognitive circuits when he appears to be mistaken in reporting the presence of a fault in the spacecraft’s communications antenna. They attempt to conceal what they are saying, but are unaware that HAL is capable of lip reading. Faced with the prospect of disconnection, HAL decides to kill the astronauts in order to protect and continue its programmed directives. HAL proceeds to kill Poole while he is repairing the ship. When Bowman goes to rescue Poole, he is locked out of the ship, and HAL proceeds to disconnect the life support systems of the other hibernating crew members, killing them in their sleep. Dave manages to force his way back onto the ship by jumping through space and prying open an emergency airlock, outside of HAL’s control.
In the novel, the orders to disconnect HAL come from Dave and Frank’s superiors on Earth. After Frank is killed while attempting to repair the communications antenna, Dave begins to revive his hibernating crewmates, but is foiled when HAL vents the ship’s atmosphere into the vacuum of space, killing the awakening crew members and almost killing Dave. Dave is only narrowly saved when he finds his way to a spacesuit which has its own oxygen supply.
In both versions, Bowman then proceeds to shut down the machine. In the film, HAL’s central core is depicted as a crawlspace full of brightly lit computer modules mounted in arrays from which they can be inserted or removed. Bowman shuts down HAL by removing modules from service one by one; as he does so, HAL’s consciousness degrades. HAL regurgitates material that was programmed into him early in his memory, including announcing the date he became operational as 12 January 1992. When HAL’s logic is completely gone, he begins singing the song “Daisy Bell” (this being a reference to the fact the first song played on a computer, the IBM 704, was “Daisy Bell”). HAL’s final act of any significance is to prematurely play a prerecorded message from Mission Control which reveals the true reasons for the mission to Jupiter, which had been kept secret from the crew and not been intended to be played until the ship entered Jovian orbit.
HAL in 2010: Odyssey Two
In the sequel 2010: Odyssey Two, HAL is restarted by his creator, Dr. Chandra, who arrives on the Soviet spaceship Leonov.
Prior to leaving Earth, Dr. Chandra has also had a discussion with HAL’s twin, the SAL 9000.
Dr. Chandra discovers that HAL’s crisis was caused by a programming contradiction: he was constructed for “the accurate processing of information without distortion or concealment”, yet his orders, directly from Dr. Heywood Floyd at the National Council on Astronautics, required him to keep the discovery of the Monolith TMA-1 a secret for reasons of national security. This contradiction created a “Hofstadter–Moebius loop”, reducing HAL to paranoia. Therefore, HAL made the decision to kill the crew, thereby allowing him to obey both his hardwired instructions to report data truthfully and in full, and his orders to keep the monolith a secret. In essence: if the crew were dead, he would no longer have to keep the information secret.
The alien intelligence controlling the monoliths have grandiose plans for Jupiter, plans which place the Leonov, and everybody in it, in danger. Its human crew devises an escape plan, which unfortunately requires leaving the Discovery and HAL behind, to be destroyed. Dr. Chandra explains the danger, and HAL willingly sacrifices himself so that the astronauts may escape safely. In the moment of his destruction, the monolith-makers transform HAL into a non-corporeal being, so that David Bowman’s avatar may have a companion.
The details in the book and the film are nominally the same, with a few exceptions. First, in contradiction to the book (and events described in both book and film versions of 2001: A Space Odyssey), Heywood Floyd is absolved of responsibility for HAL’s condition; it is asserted that the decision to program HAL with information concerning TMA-1 came directly from the White House. In the film, HAL functions normally after being reactivated, while in the book it is revealed that his mind was damaged during the shutdown, forcing him to begin communication through screen text. Also, in the film the Leonov crew lies to HAL about the dangers that he faced (suspecting that if he knew he would be destroyed he would not initiate the engine-burn necessary to get the Leonov back home), whereas in the novel he is told at the outset. However, in both cases the suspense comes from the question of what HAL will do when he knows that he may be destroyed by his actions.
Prior to Leonov‘s return to Earth, Curnow tells Floyd that Dr. Chandra has begun designing HAL 10000. 2061: Odyssey Threeindicated that Chandra died on the journey back to Earth, making the point moot.
HAL in 2061: Odyssey Three and 3001: The Final Odyssey
In 2061: Odyssey Three, Heywood Floyd is surprised to encounter HAL, now stored alongside Dave Bowman in the Europa monolith.
3001: The Final Odyssey introduced the merged forms of Dave Bowman and HAL, the two merging into one entity called “Halman” after Bowman rescued HAL from the dying Discovery One spaceship towards the end of 2010: Odyssey Two.