While most TARDISes do have voice-interaction circuits that can control minor systems (for example the Main Doors) the Navigator represents a significant advancement. While the Type 46A's CPMI had been deemed a failure, the less ambitious Navigators voice control circuits found on the Type 70 and subsequent models used voice control circuits that allow the crew to operate a TARDIS using only vocal commands. Like the earlier voice-interaction circuits, the voice command systems have a voice lock so that only someone with the right voice print can operate the TARDIS.
When activated the TARDIS can implement almost any command, including complex flight instructions. The circuits will vocally confirm the completion of each action. Despite coming into existence well before the Time War most operators of that era found it quicker and more reliable to input commands directly into the console. But by the beginning of the Time War, voice interaction was much more popular on non-military TARDISes. The popularity was such that the control rooms were no longer designed for manual control. Optional controls were still available for use in an emergency.
The following color code is used:
- Black: For information from the TV Series, including Dimensions in Time, and 1996 TV Movie.
- Blue: For information from the Novels and Audios including Target, Virgin, BCC, and Big Finish.
- Green: For information from 'licensed' reference sources such as the Technical Manual, Doctor Who Magazine, and the Role Playing Games.
- Red: For information from unofficial sources -The Faction Paradox series, behind the scenes interviews, author's speculation, and popular fan belief.
The TARDIS Technical Index is copyright Will B Swift.