The special effect I was most acquainted with in school was watching the projector lamp burn through the film when the teacher would stop the reel during the movie. We could also tell which kids had VCRs at home because their parents were time travelling billionaires.
No, no one at my school had one. The closest piece of technology we had was an HP programmable calculator (HP25C). It weighed about 10 pounds (Ok, it was about 6 oz.), had a single line LED display, and cost about $80. It used RPN (Reverse Polish Notation) (No, I'm not kidding) and allowed basic calculations up to 49 steps. Our Calculus teacher thought it was too powerful for us and banned it from his class. Yes, I saved up money and bought one of those in the late '70's. A calculator, not a Calculus teacher, that is. I couldn't afford the teacher.