A DLB (the name was invented by another user of Everything2) consists of a large matrix of coloured LEDs (the more colours, the better), connected to a small microprocessor, and maybe a serial port or something. When hooked up, it displays messages deemed to be vitally important by the operator of that DLB. But to be a DLB, more is needed. It must be flashy (various tacky screen-fading effects are encouraged), it must be sophisticated (try putting it behind a protective perspex barrier, to prevent the hoi polloi from getting too close or seeing it too well), and it must display only useless information.

Thus, a typical DLB is what you see standing above the entrance to your local First Foo Bar Savings & Loan Bank. It cycles through these messages (imagine a wipe, say erasing and displaying the messages from their end (or bottom), to prevent readers from reading):

  • "Welcome to your local branch of the First Foo Bar Savings & Loan Bank"
  • "Take advantage of our exclusive offer of tax-free loans" (the tax-free loans are offered by all the banks; the Foo Bar stopped offering them a fortnight ago, but still haven't got round to updating the DLB)
  • "Local time is 12:00" (naturally, the 12:00 is blinking; the clock hasn't been set)
  • "Temperature is 100C (40F)" (this last is a bit unreadable; some of the LEDs appear bad)