The Tektronix 909 desktop calculator is built from multiple cards, and features
lots of nixie tubes.
Unfortunately, not all of the tubes light up on mine, and some that do light up
tend to flicker a lot.
This is the Tektronix 909 with its cover open.
It's built up from various circuit boards (below).
This is one of the circuit boards from the Tektronix 909 calculator.