when did the tardis get stuck as a police box
TARDIS Although a TARDIS is supposed to blend inconspicuously into whatever environment it turns up in, the Doctor's TARDIS retains the shape of a police box because of a fault that occurred in the first Doctor Who serial, An Unearthly Child (1963). The ability to alter its appearance was first mentioned in the second episode of the series, where the First Doctor and Susan noted the unit was malfunctioning. ("It's still a police box! Why hasn't it changed?") It was first given a general term of a "camouflage unit" in The Time Meddler (1965). The name "chameleon circuit" was first used in the 1975 Target Books novelisation of The Terror of the Autons, and eventually mentioned on screen in Logopolis (1981). The circuit was called a "cloaking device" by the Eighth Doctor in the television movie Doctor Who (1996), and again a "chameleon circuit" in the 2005 series episode "Boom Town".