Matrix door

A Matrix door was a method of physically entering the Matrix on Gallifrey, (TV: The Ultimate Foe) a real world interface (AUDIO: Ascension) as opposed to merely connecting one's mind to the Matrix. (TV: The Deadly Assassin)

The sensation of passing through a Matrix door felt like being "scanned". (AUDIO: Lies) At least 14 doors existed around the Capitol, though there could have been any number of doors as K9 was able to create them, (AUDIO: Ascension) with particular ones including the legendary Seventh Door outside the courtroom on Space Station Zenobia through which the Sixth Doctor, Mel, and Sabalom Glitz pursued the Valeyard, (TV: The Ultimate Foe) the Eighth Door which simultaneously existed onboard the Doctor's TARDIS which Ace used, (PROSE: St Anthony's Fire) onboard the Time Station through which President Romana II came in contact with Rassilon, (AUDIO: Neverland) and moved beneath the control terminal for the Eye of Harmony in the Panopticon, (AUDIO: Renaissance) and the Twelfth Door through which the Daleks invaded Gallifrey from the Matrix. (AUDIO: Ascension)

The Valeyard hid another matrix door on the mudball planet orbiting Etarho, using it to escape the particle disseminator trap left for the Sixth Doctor and Inquisitor Darkel. (AUDIO: Trial of the Valeyard) A Matrix access door existed within the Vaults on Gallifrey. (AUDIO: Lies)