“It’s incredible how far display technology has come. Nowadays LED walls are found at every major concert venue, flat panel televisions are ubiquitous, and everyone has a high resolution, full color LCD display in their pocket. It’s difficult to imagine that just a few short decades ago it was a struggle to create a large, dynamic display for an economical price.
One such solution to that problem was “split-flap” displays. This technology was commonly used in train stations, bus terminals, and airports for arrival and departure boards – places where information is needed at a glance, clearly visible at all times of day, and easily updatable when schedules change. On a smaller scale it also made its way into consumer alarm clocks, one of which is immortalized in the film Groundhog Day (1993).
The displays themselves were mechanical in nature. A set of flaps were attached around a spool, each labeled with half of a character on either side. As the spool is rotated, the flaps successively flip forwards to change the character visible from the front. When a full character was displayed you’d see the front half of one flap and the back of another with a split in the middle – hence the name “split-flap”.
Recently there has been a resurging nostalgic interest in these displays. And I decided to build one for myself.”