Tautology (short story)

Tautology was a Brief Encounter short story published in Doctor Who Magazine 194.

Summary
Professor Marius writes in his computer diary that he has been posted to a station close to the space lanes and believes he will be bored there. He acquires an old computer from his niece's fiancé. Strangely, although it is from the 20th century, its technology is far in advance of that time. However, due to shuttle weight restrictions he is forced to not only have it scrapped, but also to leave behind his dog Toby. He keeps the computer's motherboard and Toby's dog tag as mementos. At the station, he befriends an electronic specialist who helps him construct a new computer based on the motherboard and sketches Marius drew. The professor plans to name it after the old computer: K9.

Characters

 * Frederick Marius
 * K9 Mark I
 * K9 Mark III
 * Gloria
 * Frank
 * Moore
 * Toby

Worldbuilding

 * Frank is a descendant of Sarah Jane Smith.
 * Marius uses a couple of tautologies in his diary, for which he chides himself.
 * Frank inherited K9 from his mother.

Continuity
The television story School Reunion sees K9 Mark III destroyed and replaced by a fourth model. Although technically Tautology does not mention which model was passed down to Frank, making it possible to retcon it being the later version, since this short story was written years before the television story, it is clear which model is intended.