'80s campus bike. Reference points follow: stamped dropouts, fat lugs to hide possible lack of mitering on gas-pipe tubing, chainstay bridge that doubles as a kickstand mount, alloy crank with non-removable chainrings and plastic bash guard, cheap side-pull brakes, non-maintainable platform pedals, Fix it up, ride the snot out of it, but don't put a lot of money into it.
Spend some time getting to know some of the fine and mid-level bikes by looking at the websites referenced by this group--vintagevelos.com, the Masi registry, and the sites of the old builders who are still at it--Cinelli, Gios, Colnago, Sachs, Serotta, Schwinn, etc. You can also search for images of many of the bikes referenced here. The differences will become obvious.