2001: A Space Odyssey Ripoff!
When it first came out, I remember sci-fi enthusiasts complaining about the elements that 1977's "Demon Seed" had in common with 1968's "2001: A Space Odyssey."
In particular, The self-conscious supercomputer with a human "HAL-like" voice...And the "psychedelic" visual interludes.
As far as Robert Vaughn's voice as Proteus...The comparison with Douglas Rain's HAL was inevitable. Both spoke with a natural human lilt and without the stereotypical mechanical stilting voice that sci-fi movies had usually reserved for computer characters. (Although Robert Vaughn's voice was given a gratuitous high-tech distortion for the time.) Both voice actors were used to instill some sense of humanity to the machine characters.
Compared with 1970's "Colossus: The Forbin Project"...Paul Frees' heavily filtered voice as the supercomputer Colossus was never meant to provoke a sense of self-consiousness or humanity...Only to voice a coldly logical automaton.
As far a the "psychedelic" visual interludes? Both "2001: A Space Odyssey" and "Demon Seed" were produced by MGM Studios in Panavision format...And the MGM visual effects department obviously wanted to show off their new electronic video effects processing in that same impressive wide format that 2001's slow-motion liquid and camera animation effects had done almost a decade before.
Finally, and most likely undetectable for most viewers, "Demon Seed" uses some of the same sound effects produced for "2001: A Space Odyssey."
But then again...MGM's sound library for "2001: A Space Odyssey" has been used over and over again in contemporary movies as well...Which is telling aspect of those MGM sound engineers' skill from almost four decades ago.