TCARS was an acronym for the Computer Access and Retrieval System used aboard 29th century timeships. It was the successor to the Federation's starship LCARS. It could be operated by touch or by simply moving one's hand over a control surface.
The TCARS computer system was used aboard Wells-class timeships, such as the USS Relativity. On the Relativity, it could be used to locate past problems in a timeline along with performing normal starship computer routines. (VOY: "Relativity")