Telector screen
From Tardis Wiki, the free Doctor Who reference
The Telector screen was device in the Doctor's TARDIS which would measure the ship current position. The First Doctor on one occasion noted to his companions Ian Chesterton and Barbara Wright that the device was not working properly. Upon exiting the ship, the group discovered that this was in result of the ship shrinking to the size of insects. (COMIC: Doctor Who in "Lilliput")
