The Doctor's TARDIS

The Doctor's TARDIS was an obsolete Mark I Type 40 TARDIS used by the Doctor as his primary means of transport. Capable, like all TARDISes, of travelling through space and time, the Doctor travelled in his vessel from the beginning of the universe itself prior to the Big Bang (DW: Terminus, DW: Castrovala, BBCR: Slipback) to the end of the universe. (DW: Utopia)

Model and type
In his first incarnation, the Doctor implied that he had built his TARDIS himself. (DW: The Chase) It was later revealed that he had stolen it, although this did not necessarily preclude the notion that he had somehow been responsible for its creation (DW: The War Games, ST: The Exiles); it was clarified that, while the Doctor had not completely built the TARDIS, he had assembled multiple components of the control console in order to grant himself the ability to control the TARDIS without the necessity of a mental link with the ship, thus preventing him from leaving a signal that the Time Lords could track after he went on the run (EDA: The Taking of Planet 5). Marnal was the Time Lord who previously owned the TARDIS. (EDA: The Gallifrey Chronicles)

The Doctor's TARDIS was referred to by the Time Lords as being a Type 40. By the time of the Doctor's fourth incarnation, all other Type 40s had been officially decommissioned and replaced by newer, improved models. (DW: The Deadly Assassin)

The Monk claimed to have a Mark IV TARDIS, while the Doctor had a Mark I. The Doctor vaguely suggested that the two "Marks" were fifty years apart, although he could have been referring to the age gap between the time differential between when he and the Monk had left Gallifrey, or the age gap between himself and the Monk. (DW: The Time Meddler)

The dematerialisation circuit of the the Master's TARDIS was a Mark II compared to the Doctor's Mark I. (It was unclear whether this meant that the Master's TARDIS, as a whole, was a Mark II.) (DW: Terror of the Autons)

Exterior
Almost all TARDISes were able to blend in with their surroundings because of a mechanism called the "chameleon circuit", or "camouflage unit". On the one later occasion which the Doctor's was functioning, it appeared to automatically choose a form, though not a particularly appropriate one. (DW: Attack of the Cybermen) Other, later models seemed to allow the pilot to choose a desired exterior The Doctor showed Adric how the TARDIS could be changed to the shape of an Egyptian pyramid if the chameleon circuit had been working properly, implying that he could control what form the TARDIS would take if the circuit functioned. (DW: Logopolis) In any case, the defining characteristic of the Doctor's TARDIS was that its chameleon circuit had broken after assuming the shape of a police box in 1963 London. It apparently had been working up until it landed in I.M. Foreman's junkyard. the Doctor's granddaughter stated that the TARDIS had previously appeared as a sedan chair and an ionic column, and both she and the Doctor expressed surprise that it had not changed form when they traveled to a new destination. (DW: An Unearthly Child)

Eventually, friends and enemies would be able to locate the TARDIS because it failed to change shape. The Daleks (DW: The Chase) even had miniature copies of the TARDIS to use as target practice (DW: Death to the Daleks). The Cybermen also recognized it (DW: Earthshock), as did the Black Guardian's operative known as the Shadow. (DW: The Armageddon Factor) On occasion, by chance, an actual police box scared away a group of invading aliens from Earth after they mistook it for the Doctor's ship. (DWM: Useless Things)

Captain Jack Harkness was on the look-out for "a version of" the police box throughout the 20th and early 21st centuries. (DW: Utopia) Members of LINDA also knew of the outer shape of the Doctor's TARDIS, as well as Abzorbaloff. (DW: Love & Monsters) The fourth incarnation of the Doctor once tried to permanently fix the problem of the faulty chameleon circuit, not wanting old enemies to have such an easy way to recognize him. He did this by measuring its exterior dimensions in relation to an actual police box and then by visiting the Logopolitans to complete the Block Transfer Computations they would have used to fix the faulty circuit. Due to interference of the Master, he never completed this task. (DW: Logopolis)

In his sixth incarnation, the Doctor thought he had succeeded. However the Chameleon circuit was still malfunctioning, which became obvious when the TARDIS appeared as first a cupboard, then a pipe-organ and later as a set of iron gates, none which fit with its surroundings. The TARDIS shortly reverted back to the old police box shape and its Chameleon circuit broke down again. (DW: Attack of the Cybermen)

Later the Doctor felt so adamantly that he preferred his TARDIS' exterior shape that he purposefully smashed the functioning chameleon circuit with a mallet, so it would never work again. (NA: No Future). The Doctor made no further known attempts to fix the faulty circuit. His ninth incarnation admitted that he was actually quite fond of its current shape. (DW: Boom Town)

When Donna Noble was briefly granted the Doctor's intelligence she began explaining to the Doctor how he could fix the chameleon circuit. Her explanation was cut short as her mind started to burn. (DW: Journey's End)

According to the eleventh incarnation of the Doctor, "It’s camouflaged. It’s disguised as a police telephone box from 1963. Every time the TARDIS materializes in a new location, within the first nanosecond of landing, it analyses its surroundings, calculates a twelve-dimensional data map of everything within a thousand-mile radius, and then determines which outer shell would best blend in with the environment. And then it disguises itself as a police telephone box from 1963."

During the Doctor's first incarnation, a faded St John Ambulance logo could be seen on the door. However, it vanished at some point during or after his second incarnation. When the TARDIS regenerated itself at the start of his eleventh incarnation, a new St John sticker was part of the door. (DW: The Eleventh Hour)

Lock and key
See also: TARDIS key Entry to the Doctor's TARDIS was effected by inserting a key into the lock, just as would be expected from a real police box. However, the locking mechanism did not respond to police-issued keys, and would not always open even if an unauthorized person used the Doctor's keys.

The external design of the key changed over time. As would be expected on a vintage police box, it primarily appeared to be an ordinary Yale lock key. (DW: Spearhead from Space, Rose, et al) However, it occasionally appeared to have a more ornate, Gallifreyan motif. (DW: Planet of the Spiders, Ghost Light, Doctor Who)

The key could be modified to track and locate the TARDIS, allowing the Doctor to find the TARDIS if it was within a hundred years of his position. (IDW: The Forgotten) The key was known to express a link to the TARDIS by glowing and/or becoming hot to the touch. (DW: Father's Day, The Eleventh Hour)

At one point, the Doctor installed a system that allowed him to lock the TARDIS remotely using a fob (as a joke, the TARDIS roof light flashed and a alarm chirp was heard, similar to that used on vehicles on Earth). He was also able to open the door remotely. (DW: The End of Time)

Interior, configuration and appearance
Periodically, the TARDIS interior went through various metamorphoses, sometimes through choice or because of other reasons, such as the Doctor's own regeneration (MA: Invasion of the Cat-People). Some of these changes were physical in nature (involving secondary control rooms, etc.), but it was also possible to change the interior design of the TARDIS as one would change the desktop theme on a computer.

Using the Architectural Configuration system, the Doctor was able to change and re-arrange the interior of his TARDIS with ease. (DW: Logopolis, Castrovalva, DWA: 2006 Doctor Who Annual) The Fifth Doctor also called this changing "the desktop theme" (DW: Time Crash The TARDIS was capable of doing this using a variation of the chameleon circuit. (REF: Doctor Who: The Visual Dictionary) The TARDIS interior walls generally consisted of roundels; circular indentations that lined all of the TARDIS walls. Some roundels concealed TARDIS circuitry and devices (DW: The Wheel in Space, Logopolis, Castrovalva, Arc of Infinity, Terminus), while others function for viewing the outside. (DW: The Claws of Axos) The design of the roundels varied depending on where in the TARDIS they were; a basic circular cut-out with black background, roundels resembling washing-up bowls stuck to the wall, recessed wood paneling with a few decorative ones in what appeared to be stained glass, translucent illuminated discs or hexagonal shapes with nodes in the centre. (DW: The Hand of Fear)

The Doctor's TARDIS originally had an internal mass of 68,000 tons. A quarter (17,000) of this mass was jettisoned in order for the TARDIS to escape Event One. (DW: Castrovalva)

Control room
There have been many variants of the Doctor's TARDIS main control room. They usually shared common features, such as: a hexagonal control console, a set of doors allowing access to the outside via the outer plasmic shell, a doorway to other rooms in the TARDIS, and a scanner or some other means of observing the outside.

Main control room
First version When the interior of the TARDIS was first seen by Ian Chesterton and Barbara Wright it was a bright white room, with roundels on the walls and a large computer bank taking up a major part of the 'back' wall. These computer banks contained the fault locator along with various systems relating to navigational control. (DW: An Unearthly Child, DW: The Daleks)

This console was removed by the Doctor in his third incarnation during his exile on Earth for use in his laboratory. (DW: Inferno) The Doctor returned it to its old place later. (DW: Terror of the Autons)

The Doctor continued to rebuild the TARDIS console and the main interior of the TARDIS console room using "UNIT funds and equipment" throughout his exile as UNIT's scientific adviser. (DW: The Three Doctors)

The Doctor briefly changed the walls of the console room with what appeared like plastic furnishings appearing along the edges of the roundels. One of the roundels served as a replacement of the scanner, a picture appearing in its centre. (DW: The Time Monster) He later reverted to the more traditional design. (DW: The Three Doctors)

The Doctor rebuilt the console following its damage by Cyberguns. (DW: Earthshock) He later refurbished it completely, giving it a sleeker, more high-tech appearance. (DW: The Five Doctors)

Second version The whole TARDIS interior went through its most radical change seen following the TARDIS's entrapment inside the Doctor's family estate, the House of Lungbarrow (NA: Lungbarrow), rebuilding itself to resemble the house after the Doctor temporarily severed the link between the interior and exterior to prevent his family stealing the ship. After he restored the TARDIS, the console had assumed a more Gothic, Victorian appearance, and included a library. Like the roof of an observatory or a planetarium, the ceiling of the control room "opened", revealing the Infinity Chamber which showed the outside and could display holographic images. The smaller scanner, which resembled an antique black and white television set, displayed other information. (DW: Doctor Who) Third version
 * See Edifice

Following the TARDIS' destruction after it was caught in a dimensional tear (EDA: The Shadows of Avalon), it reconstructed itself into a massive bone-like structure that came to be known as the Edifice; its console room at this stage was apparently based on the console room at the time of destruction, but appeared, like the rest of the ship, to be made of bone, due to the TARDIS containing the Faction Paradox biodata virus that had infected the Third Doctor after his early regeneration (EDA: Interference - Book Two, The Ancestor Cell). The console also manifested an 'avatar' of the Third Doctor composed of the dust in the ship, apparently the manifestation of the Third Doctor who should have existed before the Faction changed his history. This console room was 'destroyed' when the Doctor drained the Edifice of all its power in order to fire the ship's ancient weapon systems, forcing the universe to 'choose' realities and decide whether the Doctor remained himself or became a member of the Faction.

Fourth version The TARDIS completed its regeneration on Earth, after the Doctor exhausted its power in the destruction of Gallifrey. It's interior now resembled a mixture of the original console room and the Eighth Doctor's console room. (EDA: Escape Velocity) The Control Room was now hexagonal and contained four alcoves, two on either side of the main doors and the interior door. One contained filing cabinets and chests, another lead to the library, the third contained a laboratory, and the fourth contained a kitchen (which looked out onto a English countryside vista and was an exact replica of the kitchen in the Doctor's house in Kent). This interior was destroyed when the Doctor used the TARDIS to contain the explosion of a cold fusion generator created by the TARDIS' original owner. (EDA: The Gallifrey Chronicles)

Fifth version By the Doctor's ninth incarnation, the control room had been changed to its "Coral" theme, giving it a more organic design than the previous console rooms. (DW: Time Crash) Hexagonal impressions on the walls had replaced the roundels, and the console itself incorporated many odds and ends ranging from a device resembling a bicycle pump to a mallet used for occasional percussive maintenance. (DW: Rose onwards) It also contained a working telephone. (DW: World War Three) The console room consisted of a circular area with a red tiled ramp leading from the doors to a hexagonal platform. On the hexagonal platform was a second, circular, platform. The entire room was supported by six coral pillars that met with the top of the time rotor at the rooms ceiling. Under the main platform were storage areas large enough for the Doctor to enter (DW: Army of Ghosts), though some were packed to just below the top. (DW: The Unicorn and the Wasp)

Later, the console room was set on fire and at least one column destroyed by the Doctor's violent regeneration into his eleventh incarnation. (DW: The End of Time)

Sixth version Due to the violent nature of the Tenth Doctor's regeneration and the resultant damage to the TARDIS, it required time to repair itself. After the ordeal involving the Atraxi attempting to recapture Prisoner Zero had been resolved, the Doctor returned to the TARDIS and, upon seeing the changes to the control room, immediately proceeded to take the TARDIS to the moon and back in order to "run her in". Soon after taking Amy Pond on board for the first time, the new TARDIS console also provided the Doctor with a new sonic screwdriver, as the previous one had been just destroyed. (DW: The Eleventh Hour)

Changes to the control room included a new hexagonal console including instruments resembling a typewriter, a telegraph, a gramophone, a set of hot and cold taps, and a view-screen made by Magpie Electricals. Each side of the console was centred around a different function (Helm, navigation, diagnostic, communications, fabrication, mechanical) A larger, circular view screen was set into one of the walls. (DW: Victory of the Daleks, The Hungry Earth) There were fewer roundels on the walls than in the past, and an area located underneath the main console which housed the Heart of the TARDIS. This version also possessed an actual phone, on which people could call the Doctor. (DW: Victory of the Daleks)

It had at least three floors: a lower section, the console room level, and the second level. (DW: The Eleventh Hour)

Secondary control room
There existed a small secondary control or console room which the Doctor claimed may have been the original console room. It was far simpler than the main control room, with the console resembling a desk, no visible time rotor and all the controls hidden behind what appeared to be wooden panelling. It had more subtle roundels, some of them framing stained glass windows. For a brief period in his fourth incarnation, the Doctor used this as the main control room. (DW: The Masque of Mandragora, The Hand of Fear, The Deadly Assassin, The Robots of Death, The Invisible Enemy)

Other control rooms
There also existed a tertiary control room, which was cool and dark grey with a small mushroom shaped console. (NA: Nightshade, NA: Deceit)

The Doctor has stated that the TARDIS has many control/console rooms. (IDW: Tesseract) The status of these rooms are unknown.

Specific control systems
The TARDIS' controls were said to be isomorphic, that is, only the Doctor could operate them. (DW: Pyramids of Mars) However, various companions have been able to operate the TARDIS and even fly it. (DW: Castrovalva, DW: Four to Doomsday, DW: The Visitation, DW: The Five Doctors, DW: The Parting of the Ways, DW: The Sontaran Stratagem, DW: Journey's End, DW: The Lodger) The Time Lords are also able to pilot the TARDIS by remote control, usually, as the Doctor once bitterly noted, so he may take care of "some dirty work they don't want to get their lily-white hands on." (DW: Colony in Space, DW: The Brain of Morbius)

The second incarnation of the Doctor once used a portable Stattenheim remote control to summon his TARDIS to him (DW: The Two Doctors). The TARDIS was also vulnerable to diversion or relocation by the Guardians, Eternals, and other immensely powerful beings such as the Keeper of Traken. (DW: The Ribos Operation, DW: Enlightenment, DW: The Keeper of Traken)

For a brief time the Doctor's fourth incarnation installed a Randomiser in the navigational subsystems, though this was eventually removed. (DW: The Armageddon Factor, DW: The Leisure Hive)

The various systems of sixth version of the console room were contained on a series of six panels around the central console. The panels were centred around different functions:
 * The Mechanical Panel contained the engine release lever, door release lever, gyroscopic stabiliser, locking down mechanism (described as a physical handbrake) and the TARDIS display dials.
 * The Helm Panel contained the eyepiece (an alternative to visual scanners), time rotor handbrake and the space/time throttle.
 * The Navigation Panel contained a time and space forward/back control, directional pointer, atom accelerator (the spinning spiky ball) and the spatial location input (a computer keyboard).
 * The Diagnostic Panel contained the inertial dampers, the cooling systems (gauges), a bunsen burner and a microphone/water dispenser.
 * The Communications Panel contained an analogue telephone, digital com, voice recorder, analogue radio waves detector/monitor/changer and a scanner/typewriter.
 * The Fabrication Panel contained the materialise/dematerialise function, harmonic generator, time altimeter, a fabrication dispenser (which was described as being able to produce sonic screwdrivers and other technology - which eventually housed the Laser Screwdriver) and a Heisenberg focusing device (described as being specifically designed to break Heisenberg's Uncertainty Principle - described in Series 5 as the zigzag plotter). (VG:TARDIS )

Library
There was also a library inside the TARDIS. (EDA: War of the Daleks, NA: All-Consuming Fire, NA: The Dimension Riders) Known books included Jane's Spaceships (EDA: War of the Daleks) and Every Gallifreyan Child's Pop-Up Book of Nasty Creatures From Other Dimensions (NA: All-Consuming Fire) and The Time Machine by H. G. Wells (DW: Doctor Who) The Murder of Roger Ackroyd by Agatha Christie (first printing, signed, with last page missing), War and Peace, The Wonderful Wizard of Oz and The I-Spy Book of British Birds (BFA: Storm Warning). At one point, the console room also incorporated a library (DW: Doctor Who). Following the TARDIS' repairs, the Eleventh Doctor claimed that he couldn't find the library, and that it would show up again at some point. (DW: The Eleventh Hour)

Wardrobe
The wardrobe was where the Doctor kept some of the clothes from his previous regenerations, as well as clothing for other people. (DW: Pyramids of Mars, The Twin Dilemma, Time and the Rani, The Unquiet Dead, The Christmas Invasion, The Idiot's Lantern). It has clothing from all times and environments in it, to suit whichever time the TARDIS' occupant(s) find themselves in. At least some of the clothes had pockets that were bigger on the inside, much like the Doctor's own pockets. (MA: Invasion of the Cat-People)

Cloister room
The cloister room was related to the cloister bell, which sounded when disaster was imminent. (DW: Logopolis, The Sound of Drums, Time Crash, The Waters of Mars, The Eleventh Hour) When the TARDIS interior went through a metamorphosis, the cloister room became a grand and gothic room with an interface with the Eye of Harmony. (DW: Doctor Who)

Zero room
The zero room was a room which was unaffected by the outside world. It was used as a refuge for Time Lords undergoing difficult regenerations. This room was later jettisoned so that the TARDIS could escape from Event One. (DW: Castrovalva)

Holding ring
The holding ring was a storage area of the TARDIS which allowed the Doctor to preserve certain rooms. When investigated by Lucie, Susan and Alex, the ring was found to contain the rooms of many of his former companions, preserved as they were the last time the companion had been on the TARDIS. The rooms were saved in chronological order, heavily suggesting that Susan was indeed the Doctor's first companion. Susan later teased her grandfather, calling his habit of saving rooms overly sentimental. He countered by suggesting that the ring was one of the few ways that his time-travelling life allowed him to put down roots. After Susan, Alex and Lucie departed the TARDIS for new adventures on Earth, the Doctor reconsidered the wisdom of keeping so many rooms in stasis. Insisting to himself that he needed to look towards the future, he deleted all the rooms on the holding ring — "except that one", which was probably Susan's room.. (BFA: Relative Dimensions)

Others

 * Many of the companions of the Doctor had their own rooms, (DW: Meglos), though some lived in previously used rooms. (DW: Terminus) Some companions were seen to share accommodation. (DW: The Edge of Destruction)
 * There were at least 14 bathrooms. One had a leaky faucet for three centuries. Because he had misplaced his washers, the Doctor kept it from flooding the TARDIS by sealing it in a temporal bubble that made the same drops of water leak out over and over again. (MA: The Well-Mannered War)
 * There was a laboratory which Ace used to create her Nitro-9. (NA: Cat's Cradle: Time's Crucible)
 * The TARDIS had a swimming pool area which was used by Leela. (DW: The Invasion of Time) It was later jettisoned due to leakage. (DW: Paradise Towers) It was replaced some time afterward, and, following the TARDIS's crash landing after the Doctor's tenth regeneration, the swimming pool was in the library. There may be a new swimming pool in the regenerated TARDIS. (DW: The Eleventh Hour) He appeared to have located it soon after. (DW: Amy's Choice)
 * The TARDIS at one point also had extensive utility areas and corridors, which along with the swimming pool area, became battlegrounds during an attempted Sontaran invasion of the TARDIS. (DW: The Invasion of Time) The Doctor was under the impression it had been jettisoned until he stumbled across it during his tenth incarnation. (IDW: Tesseract)
 * Mel says that the Doctor used the TARDIS Laundromat to wash his clothes. (BFA: The One Doctor)
 * A food machine area was originally located near (but not in) the console room. (DW: The Edge of Destruction and others)
 * There was a zoo of endangered animals, a coffee machine and a jungle-like room. (DWM: Changes)
 * There was what appeared to be a cricket club and pitch deep within the bowels of the TARDIS. (DW: Castrovalva)
 * There was a large salon which the Doctor referred to as a "boot cupboard". When Sarah Jane Smith said that it was very big for a boot cupboard he replied, "I've seen bigger boot cupboards." (DW: The Masque of Mandragora)
 * The Doctor also possesses an art gallery containing various works of art from throughout history, having rescued the artworks from the disasters which history states destroyed them (BFA: Dust Breeding)
 * According to an alternate version of the Ninth Doctor there was a zeppelin hangar somewhere in the TARDIS. (WC: Scream of the Shalka)
 * There appears to be either a kitchen, or at least a refrigerator, in the TARDIS during the Doctor's tenth incarnation. It's unclear if this is the same as the food machine area mentioned above (IDW: The Whispering Gallery).
 * There may also be a garage or some similar location suitable for storing vehicles, as the Doctor is known to have at one point kept a Vespa (motor scooter) in storage within the TARDIS (DW: The Idiot's Lantern). The Sixth Doctor once rented a VW car and stored it in the TARDIS as well (PDA: Instruments of Darkness))
 * By the time of the Doctor's tenth incarnation, several rooms from years (and centuries) past still existed deep within the TARDIS, including the cathedral-like room where the Doctor once fought the Master (DW: Doctor Who), and a bedroom that was once used by Adric. (IDW: Tesseract)
 * The Doctor's TARDIS also had a sick bay, which in the sixth version was up the stairs, to the left, then left again. (DW: Cold Blood)
 * The Doctor's TARDIS contained a drawing room, which the Doctor claimed to be his "private study" (VG: TARDIS)
 * There was a Sun Room which containted a Sun Lounger (VG: TARDIS)
 * The TARDIS also contained a lift (VG: TARDIS)
 * There was also a green door near the drawing room which the Doctor told Amy not to go in (VG: TARDIS)
 * It was implied in The Masque of Mandragora that the "Relative Dimension(s)" in TARDIS means the size of the TARDIS (and therefore, the amount and size of the rooms) varies.

Temporal grace
The interior of the TARDIS was said to exist in a state of "temporal grace", which was supposed to ensure that no weapons can be used inside its environs. This last function is inconsistent in its application. During his travels with Lucie Miller, the Eighth Doctor mentioned that the temporal grace system had not worked in years. (DW: Earthshock, Arc of Infinity, The Parting of the Ways, BFA: Human Resources)


 * There are several possible explanations for this seeming inconsistency. Like the HADS (see below), the "temporal grace" could need to be manually activated (although this would raise the question of why it would be deactivated). The other possibility is that the Doctor is lying, and claims "temporal grace" to prevent intruders from attempting violence. A third option is that the temporal grace has since broken and is one of the many things the Doctor has to work on. Also note that, if real, the "temporal grace" field does not prevent weapons from being fired into the TARDIS. (DW: Human Nature)

Emergency systems
The Doctor's TARDIS contained various emergency systems, such as the Jade Pagoda, a 'life boat' of some description, which could in theory be piloted (NA: Iceberg), but in emergencies it will lock onto the nearest (spatially and temporally) planet with a breathable atmosphere and bearable climate. (NA: Sanctuary) The TARDIS also had a system which, when the TARDIS is left adrift in space unmanned, would automatically lock onto the nearest central gravity. (DW: Voyage of the Damned) There were also various emergency settings set up by the Doctor. One was set up by the Doctor as a way of rescuing his companions (but not the Doctor himself) if the Doctor's death seemed inevitable, transporting the TARDIS (with the companion inside) back to the companion's respective time and home. This would cause the TARDIS to 'die' within a period of time without the Doctor and was thus only used in emergencies (DW: Bad Wolf). Another could reunite the TARDIS with the Doctor if they were seperated; however it required another individual to enter the TARDIS and insert an 'authorised command disk' to activate it in the first instance (DW: Blink), after which it seemed to have been installed and fully integrated into the ship's systems; the TARDIS automatically commenced the emergency programme without external aid in various attempts to reach the Doctor, who had been trapped in a time-loop (SJA: The Wedding of Sarah Jane Smith).

The TARDIS also contains a switch labelled "LTD" (standing for "Locate The Doctor"). This is used by Lucie Miller in BFA: The Beast of Orlok.

The TARDIS was also capable of repairing itself after suffering a hull breach. (DW: Voyage of the Damned) The TARDIS has an alarm system known as the cloister bell that activates in dire circumstances. (DW: Logopolis, Doctor Who, Children in Need Special, Time Crash, Turn Left, The Waters of Mars, The End of Time, The Eleventh Hour.)

Another emergency program activates when the TARDIS explodes. This particular program locks the control room in a Time loop to protect its inhabitants. (DW: The Big Bang)

Defensive systems
Beyond the obviously defensive chameleon circuit, the TARDIS could teleport itself a short distance away from its current location, if it was being attacked. The Doctor called this the Hostile Action Displacement System (HADS). (DW: The Krotons)

A related, if unnamed, system was meant to protect the TARDIS from landing in the path of oncoming vehicles, by preventing it from landing on, for example, train tracks. This feature failed when the TARDIS landed on train tracks in Vichy France. The Doctor, Ben, Jamie and Polly had to physically push the TARDIS out of the railway bed before the next train came down the tracks. (CC: Resistance)

The TARDIS was at one point temporarily given a defensive shield utilizing a Tribophysical waveform macro-kinetic extrapolator. (DW: The Parting of the Ways)

Offensive systems
The TARDIS later gained some offensive systems of sort; although this could have been caused by its development into the Edifice. This weapon allowed the Edifice/the Doctor's TARDIS to destroy Gallifrey, although this was only accomplished by channelling all of the Edifice's energy into the weapons. (EDA: The Ancestor Cell)

Translation circuit
The TARDIS possessed the ability to allow both the Doctor and others to understand a wide variety of languages.
 * ''See separate article for a more in-depth discussion.

The Matrix
The TARDIS had a link to the Matrix. Following the Last Great Time War, this Matrix was the only one left. (IDW: The Forgotten)

Intuition circuits
Using a holographic representation of the universe connected to the TARDIS' neural net, the TARDIS was effectively able to make hunches, guesses where it needed to be. Though the TARDIS was able to guess where it was needed, it was unable to inform the Doctor on what he needed to do once he got there. (VD: ...And Eternity in an Hour)

Others

 * The TARDIS appeared to be able to lock-on to the presence of another Time Lord, particularly the Doctor's family. (DW: The Doctor's Daughter) Alternatively it would block access (to seemingly create a situation) whereby another linked Doctor would be created. (DW: Journey's End)
 * The Doctor made additional modifications and additions from time to time. For example, at one point the TARDIS was equipped to write computer files to standard earth CD-ROMs (DW: World War Three), and he also at one point modified the control console to accept DVDs in order to allow Sally Sparrow to use a specialized control disc to activate the TARDIS (DW: Blink).
 * The TARDIS can be put one second out of synch with time. The Doctor did this once in order to prevent the Master from taking it. (DW: The End of Time)
 * The TARDIS also has stabilizers activated by blue buttons. These were first used by River Song, though it is unknown if the Doctor knew about these or not, though he said that they made the journey no fun.
 * The TARDIS also apparently has brakes, which, according to River Song, are always on, which is why the TARDIS lands with a characteristic wooshing noise. When she landed the TARDIS without the brakes on, it landed without any sound. Its possible she was joking about him leaving the brakes on as all other TARDISes take off with the same sound; most likely she activated a 'stealth materialisation' method that the Doctor rarely uses.
 * The TARDIS also has buttons for Ketchup and Mustard. (DW: Vincent and the Doctor)
 * The TARDIS had a part called the "rectifier" and another called the "zigzag plotter" which looks like a car gear lever. The latter only works if you stand in a specific place while using it. (DW: The Lodger)
 * The TARDIS' engines automatically shut down when it is vacated. (DW: The Pandorica Opens)

Personality
As TARDISes were intelligent, the Doctor's TARDIS had also developed a personality. It had been called "sentimental" (DW: Doctor Who (1996)) and "stupid" (by K-9) (DW: The Invasion of Time). Though intelligent, it was generally unable to communicate in words with the Doctor, relying on other methods of communication. (DW: The Edge of Destruction)

The TARDIS has also displayed a prejudicial fear of the time-locked Jack Harkness. (DW: Utopia) The TARDIS showed a similar hostility to Charley Pollard when she began to travel with the Sixth Doctor (BFA: The Condemned), apparently due to the paradoxical nature of her very existence: having originally travelled with the Eighth Doctor and having been saved from the incident that should have resulted in her death (BFA: Storm Warning). This resuled in the TARDIS 'refusing' to protect Charley from viruses, like it had protected his previous companions. (BFA: Patient Zero)

When the Doctor's history was changed so that his third incarnation regenerated ahead of schedule, the TARDIS sensed that he had been infected with the Faction Paradox biodata virus &mdash; intended to turn him into a member of the Faction &mdash; and took the infection into itself, holding itself together even after being nearly torn apart in a dimensional anomaly (EDA: The Shadows of Avalon) because the alternative was to allow the Doctor to become corrupted by the Faction.

When the Doctor was attacked by Es'Cartress‎, the TARDIS tried to help him in the Matrix, taking the forms of his companions and helping him regain his memories. (IDW: The Forgotten)

Although the Doctor was reluctant to believe it possible, his TARDIS seems to have such a strong affinity for the Doctor that it would open and shut its doors when he snapped his fingers. The Tenth Doctor tested this ability after being informed of it by River Song, and was able to do so.

The Doctor has shown great tenderness towards the TARDIS, referring to it as his "dear old friend" on one occasion (DW: The Deadly Assassin), and simply "dear" on another. He also referred to it as "you sexy thing" shortly after its own regeneration. (DW: The Eleventh Hour) He has most commonly referred to the TARDIS as "she" or "her". Although this would seem to be a term of endearment (much like how Earth males refer to their cars as "she's", as well as sailors and their boats), certain spin-off media suggests that the TARDIS may actually be female. (ST: The Lying Old Witch in the Wardrobe)

Problems
As the TARDIS was one of the oldest in full service and given how much the Doctor used his TARDIS, many problems had cropped up during its years of service.
 * The spring on the Fast Return Switch jammed. (DW: The Edge of Destruction)
 * The TARDIS gravitational tractor beam functioned only sporadically since it was used to pull a neutron star away from Chloris. (DW: The Creature from the Pit) Compassion was unable to use it to rescue the Doctor when he was trapped outside the TARDIS (EDA: The Taking of Planet 5), but it was functioning once more to enable the Doctor to rescue the rocket from Krop Tor (DW: The Satan Pit) and once more to pilot Earth back to its position in space. (DW: Journey's End)
 * For a time, the Doctor used a TARDIS which had once belonged to a dead version of his third incarnation, which the main universe's Doctor later found. (NA: Blood Heat) He regained his old TARDIS later. (NA: Happy Endings)
 * As stated before, the chameleon circuit no longer works, giving the TARDIS its traditional police box shape. Attempts have been made to remedy this, but they are usually interrupted or fail.
 * The TARDIS pool leaked and was jettisoned, (DW: Paradise Towers) but the TARDIS gained two new ones following its regeneration after the Doctor's second exile on Earth. (EDA: Escape Velocity)
 * To be piloted correctly the TARDIS needed six pilots, one on each side of the hexagonal console.(DW: Journey's End) As the Doctor was generally the only one to fly it, he had frequent problems with piloting, making a shaky ride. This may also explain why he occasionally has trouble landing in exact dates. Seen in DW: Aliens of London when he intended to return Rose Tyler twelve hours after her departure from earth (DW: Rose) but instead landed twelve months later.
 * The Temporal Satnav was said to be "on the blink". (DW: Dreamland)
 * According to River Song, the sound made by the TARDIS when it dematerialises and rematerialises is actually not supposed to happen, but the sound is generated by the Doctor leaving the brakes active (DW: The Time of Angels) (the fact that other TARDISes have been heard to make this noise suggests that it may not be an error on the Doctor's part; possibly River activated a 'stealth materialisation' the Doctor never bothers with).
 * The TARDIS exploding is powerful enough to crack all of space and time. (DW: The Pandorica Opens) However, it may be unfair to describe this as a problem, as the explosion was the result of an unknown force influencing the TARDIS.bThis also shows that the TARDIS is, despite being very old, still very powerful, since the explosion ripped open a crack in time.

Behind the scenes

 * An online comic WC: Just Another Thursday by Paul Cornell, published on the BBC website in 2008, suggests that the TARDIS has the ability to change its size to an almost infinite degree, at one point becoming even large enough to envelop and protect all of Earth. Given that this rather extreme ability has not been mentioned elsewhere, and given the nature of the BBC Writers' Comics series as being fun one-offs as opposed to serious contributions to the canon, it can't at present be said whether the TARDIS actually has this ability.
 * The ubiquity of the TARDIS to the Doctor Who franchise was recognized in late 2009 when the BBC unveiled a new version of the Doctor Who logo which began to be used in 2010; the logo incorporates the initials DW formed in the familiar police box shape of the Doctor's TARDIS.
 * Although the TARDIS has been a constant presence in the series since 1963, it has almost always been essentially a mode of conveyance, with the majority of stories taking place away from the vessel. There have been a few exceptions, such as DW: The Edge of Destruction and Time Crash in which the entire action of a story takes place within the TARDIS. DW: The Invasion of Time was the first story to give viewers an extensive tour of the bowels of the TARDIS (other than occasional prior glimpses of individual rooms); a more modest "tour" occurred in DW: Castrovalva. Viewers also saw new aspects of the TARDIS in the 1996 TV movie. In the comic strips, several stories have taken place almost entirely within the TARDIS, including DWM: Changes and IDW: Tesseract.
 * In a recent interview with the creators of Series 5, some details about the new "redecoration" of the Doctor's TARDIS were revealed: "It must be three times the size of Tennant’s, on multiple levels with staircases in between. Less grubby than its predecessor, with a transparent plastic floor on the main level, its walls are resplendent with polished copper and its central column features a blown glass decoration that could be straight from Tales of the Unexpected. There are old car seats and downstairs – downstairs! – a swing. With a nod to Paul McGann’s Tardis, the central column features an old TV screen on an extendable trellis. It also has a 1980s-style computer keyboard, and a His-Master’s-Voice style trumpet speaker."