Short Story:The Computer Who Wrote to Santa Claus

"The Megabyte Drive to Believe in Santa Claus" is an early story by Terry Pratchett which appears in the anthology A Blink of the Screen. It concerns a Dawn Age computer (in the unbelievably primitive 1980's) that develops sentience and asks for a Christmas present from Santa Claus. This was later recycled into the episode in Hogfather where Hex tremblingly avoids Big Red Lever Time and requests, and gets, a teddy bear from the entity who is standing in for the Hogfather.