What does it looks like?

It more or less looks like an ordinary vacuum tube, but if you look closer inside the glass, you can see a bunch of overlapping numbers(0 to 9). This kind of lamp was used a lot during the 60's.

This lamp comes from a big calculator(bigger than a typical modern computer) that I disassembled when I was 10 years old. This tube is 1" high, is model no. CD78 and is made in Japan. Nixie tubes like this exists in many sizes, even 6" tall.

I would like to have 6 identical tubes like this one, to build a clock. In my opinion, a nixie display is way nicer than a LCD or LED display.

Here is a collection of pictures under normal room light:


Here is a collection of pictures taken in the dark:


Again pictures taken in the dark, but less exposed.

How to use them

Approximately ten years after obtaining this tube, I finally learned how to make it work. I had already tried a few times without success. The reason is that this tube needs approximately 130 volt to light up. I never thought a voltage this high was required.

They are very easy to control. The positive voltage goes on the pin connected to the grid. Next, you just need to tie the negative wire to one of the digit pins to make the corresponding number illuminate.

I designed a circuit to make the lamp count continuously. Here is what it looks like:

Here is the schematic: nixie_counter_shema.gif. NOTE: The transistors are MPSA42.
And here is an image of the PCB layout in postscript: pcb.ps

In FF7

The pseudo current floor indicator in the elevator at the beginning of FF7 appears to be inspired from nixie tubes. The fact that digits appear in the same place (even simultaneously), the circular shape, the presence of a grid...


Otherwise, I think the on-screen timer is really nixie-like:


Of course, in all cases, the color is off. So it could also be neon tubes. But hey, in the end, it's just a game.