Everyone loves the look of Nixie tubes, with their glowing orange characters made of curvy filament. But we usually only see makers using Nixie tubes for one purpose: clocks. That’s unfortunate, because they have a lot more potential, as illustrated by Bob Cascisa’s Nixie tube slot machine game.

This is a really delightful device that puts the slot machine experience into a handheld form factor, with a beautiful Nixie tube display. It has a single button to spin the “wheels,” and seven Nixie tubes to show the action. The top three Nixie tubes represent the wheels and they cycle through distinct symbols. The bottom four Nixie tubes show the player’s balance to keep track of payouts.

The bottom Nixie tubes are IN-12 models, which are Soviet NOS (New Old Stock) models capable of displaying numeric digits. The top Nixie tubes are rarer IN-7 models that can display a handful of symbols that would be useful for lab instruments, such as ?. Cascisa chose those IN-7 tubes because their symbols have a more iconographic appearance than standard alphanumeric characters, which English-speakers would try to read.

An Arduino Nano board controls the gameplay. It plugs into a custom PCB that Cascisa designed to house all of the components necessary to drive the Nixie tubes — a difficult job compared to modern LED and LCD displays. It requires a power supply that can provide high voltage to the Nixie tubes. Power comes from an 18650 battery pack inside the simple enclosure, with a charging port on the side. 

By Vegas slot machine standards, the gameplay is pretty simple. But this unit’s Nixie tube display certainly looks much nicer than the retina-scarring graphics on those machines.