My wife worked for Thinking Machines back then. I remember that they'd asked Cray to loan them a supercomputer for the film because that's the computer used in the book. Cray brushed them off, so they turned to Thinking Machines who were happy to do it.

To thank them, the producers rented a theater in Cambridge, MA to screen the film just for Thinking Machines and I was also able to attend. By far the biggest reactions from the audience that night were when the CM-5 was shown for the first time and then when the young actress says, "It's a Unix system. I know this"