Dusty Vacuum Tubes: Science Fiction

The glimmer of light shining through the room bounced off dusty vacuum tubes and long-dead lights. Once this basement had been a hive of activity, the backups for a massive computer that took up the entire building. That had been long ago, though, and the building had long since been converted to office space, the basement forgotten and grown dusty and covered with webs once the owners figured that moving everything would be a very cost-inefficient venture. The processors were even plugged in, because a janitor had maliciously figured that a little extra power drain was just what his asshole employers needed on their energy bills. Over the size of the entire building, though, the accountant hadn't even noticed the difference, so even that small bit of spite--

Inspiration: Article about computer stuff...other than that, not sure.
Story Potential: Medium.
Notes: Nice creepy set-up, but where from here? Somehow, this little old computer saves the world....