Indoors, cathode ray technology usually wins hands-down over liquid crystal displays, because the CRT generates its own light whereas the liquid crystals simply reflect whatever light is available – but in bright sunlight, the advantage is reversed: that is why, instead of going for an array of 14,400 light bulbs in its new electronic scoreboard, Varitext Displays Ltd of Newport, South Wales, has applied a sort of analogue of the LCD concept, using 14,400 rotating metal discs, black on one side, white on the other, so that to make up the characters, the discs are rotated by applying a 0.5mS 12 volt charge to electro magnets behind the appropriate ones, under the control of an Amstrad Plc micro; another benefit is that light bulbs burn out and need to be replaced.
