Aerocondor y hoy por Aero Vip.
TAP was operating domestic regional flights in the 80's, an interesting route network which included flights to places like Covilhã or Viseu. This is the only TAP system timetable I have at home that includes these flights. Only one of these routes is still in operation (Lisbon-Vila Real-Bragança), once operated by Aerocondor and nowadays by Aero Vip
Aeroporto do Porto / Facebook)