The programming component for this boils down to a couple of lines to call some kind of frame buffer image viewer, but it fits thematically with the NC demo system from twenty years earlier!
The actual command used seems to change depending on the version of Raspbian used on first install (it's usually the
fbi command, unless it's not), but basically it's setting a computer up to run a script as soon as it boots up, which loops through the image files in a particular directory, and keep going even if there's an error that causes the display software to crash. As long as the screensaver has been properly disabled, we're all good!
As in the older (1997) system, a lot of the hard work is done beforehand with the design of the slides. I created the quarterlymagazine style slides based on the actual magazine front page template that Steve created, but everything else is all my own work!
The Pi is so small, the TV powers it via a USB cable. Switch on the TV, the computer comes on and starts the slide show automatically. TV is off, computer is off. It powers itself down at the end of the day to avoid damaging the drive (an SD card) when the TV is turned off. Add a display cable and some gaffer tape to keep it in place, and that's all you need.
Images are updated over a wifi connection, and if the software doesn't pick up new images automatically I added a web-based reboot button so I can reboot it from my 'phone without having to run up and down stairs.
The quality of the design work displayed on the previous system had always been terrible, so when the old laptop and TV died we decided to take over responsibility just to get to improve the design work. To achieve this without putting anyone's nose out of joint we used the price as the main selling point. A Pi costs far less than a new laptop, and we got a more efficient LED TV cheap as it was refurbished. There's a couple of stuck pixels but it's hardly noticeable.