CT Has anyone seen ESB on home video before it was released?

I have, it was on TV (I assume CCTV, from a video tape) in my school. It must have been some time in 1980, or early 1981 at the latest. I could only watch a few minutes of it, because it was before or after class, inside the classroom. Then either the teacher came and switched off the TV or I had to go to the next class. The movie was not officially released on home video until November 1984 (according to another source it was 1982), correct? So how come it was available to my school that early? Do they have special "pre-releases" for schools for some movies? It was definitely not a trailer but part of the actual movie. I assume they played the whole movie, just didn't get the chance to watch it. That was my first glimpse of ESB, as I didn't have a chance to see it in a movie theater until summer of 1981. The picture quality was pretty decent so it didn't look like a pirate copy. A school would not have allowed pirated movies to be played in any case. Or were the laws less strict at that time? Anyone else experienced similar situations? Could it have been on TV before it was released on home video? I couldn't find any info on the movie's TV premiere. Does anyone know when it was? I had thought movies were always released on home video before they are broadcast on TV. Could ESB have been an exception? We were shown other movies during class as part of the curriculum, such as Romeo & Juliet and 2001. But those were older movies. In any case why would a teacher show Star Wars in class? My school was an overseas American school by the way.