I have an old PC that I recently re-upped with Debian (forget which one, the most recent version). Here are the specs:
P3 1.2 GHz 768 MB DDR2 80 GB 7200RPM HDD Gigabit LAN
Is this sufficient for a TF2 dedicated server? My internet connection can definitely handle it and the server doesn't need to be huge, just fit some number of people.