100,000 BC - S1-E1
Visible crew/equipment: The boom mic makes an quick appearance about 18 minutes into episode one. It is in the upper left corner when the camera switches from a close up of the Doctor and Susan to a medium shot of all four characters.
Answer: TARDISes are generally available for properly authorised use on Gallifrey; they're not usually assigned to a particular Timelord on a long-term basis. The Doctor stole his when he left his homeworld.
Tailkinker ★