Vacuum tube technology.
I bought several of these VFD tubes (NOS) from an ebay seller.
With a datasheet from a similar tube RadioShack once sold long ago and a pin diagram for this device that I found on another webpage, I began experimenting almost immediately.
This is the 'final' demo circuit.
The segment anodes are pulled up, externally, with 10K resistors. Each '2003 output shunts the segment anode to which it's connected. CG is the control grid, it's a display enable for mux'ing.
[ i.e. logic input HI → output LO (to Gnd.) → segment Off ]
The filament runs on 1.5V
Here's a video demo, going through decimal numerals, 3 bit binary and a chase routine.
