Starship data recorder
From The Stargate Omnipedia
Small, modular unit installed in the port fore of ships governed by humans, most notably the Daedalus-class craft. The unit records audible dialogue, and likely maintains other records of shipboard data.
KEY EPISODE
Company of Thieves - In search of the Odyssey, Daniel and Vala come across a trader who has the ship's black box in his possession.