Victor Milson: Millson to Floyd: It's been twelve hours since I made my request for information! I need a reply - all hell is breaking loose down here! I have enough problems without you pulling some kind of a stunt! I just hope there's an Earth for you to return to! Make that report I asked for and make it immediately.
HAL 9000: Do you want me to repeat the message, Dr. Floyd?
Dr. Heywood Floyd: Who recorded it?
HAL 9000: This is not a recording.
Dr. Heywood Floyd: Who's sending it?
HAL 9000: There is no identification.
Dr. Heywood Floyd: I don't understand.
HAL 9000: Neither do I.
Dr. Heywood Floyd: Is this message by voice or keyboard?
HAL 9000: I don't know.
Walter Curnow: I feel so stupid. How do you say, 'stupid'?
Maxim Brajlovsky: Durak.
Walter Curnow: That's me.
Maxim Brajlovsky: You shouldn't feel like that. The same thing happened to me the first time I did this.
Walter Curnow: When have you ever done this before?
Maxim Brajlovsky: Never.
Answer: The most likely reason the name was changed was probably a literary one. It makes it easier for the audience to differentiate SAL from HAL, showing how they are two distinct computers playing different roles in the film. It may also just be a feminine nickname being that SAL has a female voice.
raywest
I thought perhaps "SAL" was a nickname, also, until I saw that the computer's maker nameplate reads "SAL 9000" (visible in close-ups of SAL's glowing eye).
Charles Austin Miller