The Glow Must Go On

In some ways, the simple graphics and sounds produced by early digital computers are more appealing than the ultra-high resolution graphics and true-to-life sound effects made by today’s computers and game consoles. Maybe it is that these vintage machines kick our imaginations into overdrive because everything isn’t perfectly spelled out for us. Or perhaps it is nothing more than the rose-colored glasses of nostalgia. Whatever the case may be, lots of people prefer the classics over the cutting edge.

A particularly excellent example of early computer graphics and sound used to be on display at the Seattle-Tacoma International Airport. NETWORK IV was an interactive light and sound show first installed in 1973. A wall of 1,024 neon glow lamps was controlled by a Data General Nova 1210 minicomputer, generating all sorts of images and animations that were appropriately trippy for this era.

This system was on display for decades, but was ultimately removed in the early 2000s. Andrew Seawright thought it was a shame that the NETWORK IV was no longer in operation, so he decided to create a reproduction of the original system so that the show could go on — even if it was in a much smaller, tabletop size.

The build was made easier by the fact that, while the NETWORK IV no longer exists, there is still plenty of documentation — and even a copy of the original software — to work with. A Data General Nova 1210 minicomputer is not so easy to get one’s hands on these days, however, so Seawright substituted a Raspberry Pi 4 computer running the SIMH emulator that can mimic its operation. With this setup, the original, surviving source code (extracted from paper tape) could once again be executed.

A Teensy 4.0 microcontroller and a DAC reproduce the sounds generated by the NETWORK IV, and an 8 x 8 grid of buttons allows users to control how it sounds. Another Teensy 4.0 drives a set of four LED matrices, each 16 x 16 pixels in size.

The miniaturized version may not have all the charm of the original, which took up an entire wall with its display and had a Nova 1210 minicomputer rack standing nearby, but it is still both an interesting piece of art and an educational tool that gives us a window into the operation of computers of the past. Be sure to check out the video for some spectacular blinkenlights.