The scenes with all of the computers at the military base were filmed in the backstage computer rooms at Walt Disney World's EPCOT Center.
When released in theaters, there was a promotional gimmick where, if you went to the ticket window and told the employee what "D.A.R.Y.L." stood for, (Data Analyzing Robot Youth Lifeform), you would get a free gift. The gift was a mini-poster for the movie.
During development, the movie's plot and storyline were a closely guarded secret, including the meaning of the acronym "D.A.R.Y.L.".
(at around 1h 9 mins) Dr. Lamb says, "General, a machine becomes human when you can't tell the difference anymore." This summarizes the famous Turing Test, devised by Alan Turing, a founder of modern computer theory.
In response to whether acting is work or fun, Barret Oliver states in a 1985 "Star Log" interview: "I think it's fun, but it really is a job. In D.A.R.Y.L. (1985) there was a part where I had to freeze to death and they didn't even use it. It can get kind of frustrating.