SAL 9000
HAL 9000 has at least one Earthbound twin, SAL 9000. SAL makes its first (and only) appearance in the novel (and subsequent film version) 2010.
Before the Soviet–USA mission to retrieve Discovery, Chandra uses SAL for a simulation of the possible effects that a prolonged "sleep" (disconnection) might have induced in HAL, and the project is code-named "Phoenix". When Chandra asks SAL to guess the reason for the name Phoenix, she understands that there are many possible meanings, and her first guess that it refers to the tutor of Achilles is not what he had in mind; her display of culture makes it clear that SAL has access to some form of encyclopedic knowledge database or has it built in with the rest of her programs.
SAL is clearly "female" and features camera plates similar to HAL, though the "eye" is blue instead of red. Dr. Chandra has a private terminal to SAL's mainframe in his office, and his influence causes her to develop a slightly Indian accent (2010: Odyssey Two). In the film version, SAL is voiced by Candice Bergen, who was credited only under a pseudonym (as "Olga Mallsnerd", a combination of the surname of Bergen's husband, director Louis Malle and that of Mortimer Snerd, one of her father Edgar Bergen's famous puppet characters).
2010 reveals that another ground-based HAL machine undergoes the same psychopathy that HAL does when forced to experience the same contradiction.
During the Discovery mission (in the 2001 novel and film), when Bowman and Poole have problems with HAL, an Earthbound Mission Control technician reports to them on the use of two unnamed sibling HAL computers on earth as reference simulators. When the sibling computers fail to predict any communications failure, Bowman and Poole begin to doubt HAL's reliability. It may be speculated that one of these sibling computers is SAL.
On the popular children's television show, Recess, there is a SAL 3000 that is installed as a system to aid the school but becomes sentient and out of control.
It is not stated whether "SAL" is just a nickname or an acronym similar to "HAL".