It is a truth universally acknowledged that computers-real and fictional--need names. These names can be foreboding or friendly, and sometimes funny. For the last several decades, computer names have played off each other in sometimes surprising ways.
The world's first fully electronic digital computer, designed and built by the U.S. Army during the Second World War, was ENIAC (Electronic Numerical Integrator And Computer). It weighed over 30 tons and took up an entire room. ENIAC was quickly followed by BINAC (Binary Automatic Computer) and UNIVAC (UNIVersal Automatic Computer). By 1950, John yon Neumann had developed MANIAC (Mathematical Analyzer, Numerical Integrator And Computer), the computer that helped the U.S. produce the hydrogen bomb. Other early computers were EDVAC, SILIAC, ILLIAC, OARAC, and the Rand Corporation's whimsically named Johnniac (for John von Neumann, who supervised its production). In this last example, the -AC at the end stands for nothing--it's just part of the convention of computer naming.
Early fictional computer names all seem to comment on ENIAC and its cohorts. The computer in the 1957 Spencer Tracy/Katherine Hepburn movie Desk Set is EMERAC (Electro-Magnetic MEmory and Research Arithmetic Calculator), called Emmy for short. (Computers, when given names, are often assigned genders; these genders sometimes change.) Kurt Vonnegut's 1950 short story "EPICAC" contains a computer of that name; the acronym is never explained. Danny Dunn and the Homework Machine, published in 1958, contains MINIAC (MINiature Automatic Computer), called Minny. John Barth's 1966 novel Giles Goat-Boy has WESCAC (WEst Campus Analog Computer). Isaac Asimov has Multivac, James P. Hogan has ZORAC and BIAC (Bio-Inter-Active Computer), Kendall Foster Crossen has SOCIAC, Philip K. Dick has Autofac, and John T. Sladek has QUIDNAC. (Most of the fictional -AC computers are evil or in some way untrustworthy.)
Before ENIAC, the British had Colossus, a colossal mechanical computer designed to read encrypted messages. One presumes it was named for its size, but perhaps the name is a reference to the Colossus of Rhodes, an enormous statue of Apollo considered one of the seven wonders of the world. Colossus is also the name of the evil computer in D. F. Jones's 1966 science fiction novel Colossus and the 1969 film based on it. Other classically oriented computer names include Asimov's Nestor, Robert Heinlein's Minerva, and Arthur C. Clarke's Athena (an early incarnation of HAL).
Computers are often named after ancient deities and related terms: a 1966 Dr. Who episode entitled "The War Machines" has WOTAN (Will Operating Thought ANalogue); another Dr. Who episode, "Face of Evil" from 1977, has a computer/god named Xoanon (a word meaning "a carved statue of a deity"). Roger Zelazny has Loki 7281 in the short story of that name. And Jeremy Leven's 1982 novel Satan, His Psychotherapy and Cure contains a computer named QED (Quintessential Entropy Device) that refers to itself as Satan.
Probably the creepiest and most malevolent computer I found in my research is AM in Harlan Ellison's "I Have No Mouth and I Must Scream." The humans in the story discuss AM's name: "At first it meant Allied Mastercomputer, and then it meant Adaptive Manipulator, and later it developed sentience and linked itself up and they called it an Aggressive Menace, but by then it was too late, and finally it called itself AM, emerging intelligence, and what it meant was I am ... cogito ergo sum ... I think, therefore I am." I should think there's also a reference there to the biblical "I AM THAT I AM," usually rendered in all capitals; it's God's answer to Abraham's question "Who are you?" in Exodus 3:14. God goes on to say "Thus shalt thou say unto the children of Israel, I AM hath sent me unto you." One of the proofs that AM has grown all-powerful is that he has the power to turn around and name humans. One is Nimdok, "the name the machine had forced him to use, because it amused itself with strange sounds. …