Know of a DVR device with no monthly subscription?

I have cable TV, but no cable box or anything (living in dorms). I was wanting a DVR device that will run similarly to Windows Media Center that I can plug the coax cable straight into and set up recordings. I don't want something to display content that is already on my computer, I need a device that will act pretty much the same as Tivo using just a coaxial cable (cable TV thing) input.