Computer system
From Tardis Wiki, the free Doctor Who reference
The TARDIS computer systems were the specific computer components of the Doctor's TARDIS, although the Doctor had referred to the TARDIS in general as a computer.
Gabriel and Tanith took control of the computer systems, making the TARDIS perform the calculations related to pulling creatures erased from destiny to the Shadowfell on Earth. The Seventh Doctor stated that with the computer systems tied up, the ship could not dematerialise. (PROSE: Falls the Shadow)