Our first dirtcup machines came out in 1982 on the top of the line Decade 80. It was also featured on "lesser" models as the decade wore on. The most unique household model to feature the dirtcup was the 1983 "75th Anniversary" model with a chrome painted base. The dirtcup continues to this day as a commercial model. This set up was a love it or hate it affair. I personally do not like them as they are too messy to empty. I much prefer a bagged cleaner. Yours appears to be a later 80's version. Enjoy and Happy Hoovering!
--Tom