Is This the Most Beautiful Calculator Ever Made?
Oskar used Soviet IV-12 VFD tubes to build one of the most gorgeous number crunchers we’ve seen.
It has been decades since manufacturers bothered to make their calculators beautiful. They’re utilitarian commodity items and style is a very low priority in most cases. And that leaves a gap in the market for makers to fill. Oskar did so with this stunning handcrafted calculator that features a display built using Soviet IV-12 VFD tubes.
Nixie tubes may receive most of the attention because of their very distinctive warm orange glow and curvy digits, but they aren’t the only option available to makers searching for a vintage look. In the past few years, we’ve seen a huge surge in interest in VFD (vacuum fluorescent display) technology. VFDs come in many forms, but they typically have a characteristic bright cyan color that feels vintage now that the ‘80s and ‘90s are far enough in the past. One particularly interesting form is the VFD tube, which encases a multi-segment (often seven-segment) VFD in a glass tube similar to a Nixie tube. For this clock, Oskar used IV-12 VFD tubes that were manufactured in huge numbers in the Soviet Union before its collapse.
These tubes operate a lot like seven-segment LED displays, but with an additional pin to enable to entire grid and two pins to heat up the filament. IV-12 tubes require 25 volts (and 1.5V), but that’s a lot better than Nixie tubes, which often require more than 100V. Because of their similarity to seven-segment displays, Oskar was able to multiplex the IV-12 tubes and reduce the number of pins required on the microcontroller. These tubes don’t include a decimal point segment, but that’s a minor inconvenience in most situations.
The microcontroller is an ATmega328 on an Arduino Nano board. It reads user input through a custom keyboard made with Cherry MX Brown mechanical key switches and standard key caps. A custom PCB helped to simplify wiring.
The enclosure is gorgeous wood and constructed it in an interesting manner that saved a lot of money. Its panels are laser-cut plywood glued together, but on its own that results in box that looks like it is laser-cut plywood glued together. So, Oskar covered the entire exterior in a thin walnut veneer. That looks great, and can accept stain and finish. Assembled and powered-on, this calculator is a beauty.
