Quite few non major airports are still heavily pen and paper reliant methods to some degree.
An example are islands that serve few flights per week and can't justify heavy update investments.
Airplanes are generally spaced by hours and you need to do your math about where the airplanes are by hand. But again there's so little planes that risks are minimal.
Indeed, but the set of aerodromes that are large enough to have a tower controller but not large enough to have their own radar surveillance is shrinking all the time. Radar is getting cheaper and what with ADS-C and TA/RA, a big reason to have ATC even without radar is vanishing (namely that of preventing collisions close to the airport). Oceanic control is probably the closest you can get nowadays to routine ATC without radar, even though they now have automatic position reports via satellite.
An example are islands that serve few flights per week and can't justify heavy update investments.
Airplanes are generally spaced by hours and you need to do your math about where the airplanes are by hand. But again there's so little planes that risks are minimal.