Computercide (1981)

The year is 1996 and Michael Stringer is the only private eye left on Earth. One day, he is hired by a woman to investigate Eden Isle, a complex for people who want a perfect life started by her industrialist father named Korter. Interestingly, Korter was found on a beach and is 20 years younger than he was before. When Stringer gets into the complex, he is caught in a web of mystery that he might not get out of.