Maxim Brajlovsky: Easy as cake, huh?
Walter Curnow: Pie. Easy as pie.
Dimitri Moisevitch: I want to play a game with you, Dr. Floyd.
Dr. Heywood Floyd: I don't have time for games.
Dimitri Moisevitch: This is a good game. It's called "The Truth." For two minutes, I will tell only the truth, and so will you.
Dr. Heywood Floyd: Two minutes?
Dimitri Moisevitch: Two minutes.
Dr. Heywood Floyd: Make it a minute and a half.
Dimitri Moisevitch: One minute and three quarters.
Dr. Heywood Floyd: You start.
HAL-9000: What is going to happen?
Dave: Something wonderful.
HAL-9000: I'm afraid.
Dave: Don't be. We'll be together.
HAL-9000: Where will we be?
Dave: Where I am now.
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