The TASID was the fictional Professor X's form of travel, described by Benny Summerfield as "a pantomime version of the TARDIS". While its exterior resembled a pillar, its interior was a brightly lit control room, filled with computers and levers. The Professor bought it off a man named Sid. (PROSE: No Future)
Behind the scenes[]
Professor X's status as a tribute to the Doctor Who series itself makes the TASID a rather explicit reference to the Doctor's TARDIS.
TASID may be a play of the word "tacit", as it can be understood as a tacit reference to the TARDIS.