Ancient database

From The Stargate Omnipedia

Databaseancient.jpg
Computer database located in the city of Atlantis, containing various information on the city and the Ancients who once inhabited it. The database includes a complete record of Ancients who returned to Earth following the first Siege of Atlantis (including Merlin) and the sinking of the city.

KEY EPISODES

Avalon, Part 1 - Daniel skims through the Ancient database and recognizes a familiar name.
Air, Part 1 - The Icarus Base successfully connects to a 9-chevron Stargate address, discovered two years earlier in Atlantis's database.