Sparky the Computer is a artificial intelligent personality that was installed onto the Babylon 5 mainframe computers shortly after completion in 2256. The A.I. was an experiment and proved a complete failure, as the "personality" was stubborn, uncooperative, and "emotional."
Sparky was quickly disabled and remained that way until 2260, following Babylon 5's declaration of independence during the Earth Alliance Civil War, when Michael Garibaldi accidentally reactivated the files he was contained in. He was quickly disabled again a few hours later (just as soon as was possible).