Is Robocop the first movie to do this?
A robot/machine with secret coding that prevents it from acting against its evil creators.
share"It is impossible for me to harm, or, by omission of action, allow to be harmed, a human being."
Bishop, "Aliens" (1986)
Sounds a lot like Asimov.
Yes, I'd watched that recently, maybe that's why it's in my head.
I'm sure it was used in novels before cinema.