Belatedly decided I should do something for the holiday, since none of my other plans panned out, and hopped on my bike to find a vantage point. The shore of Greenlake was pretty good. So I watched people commemorate 1776 by imitating 1812, listened to another watcher explain why they voted for Bush, then headed home.
I hadn't ridden my bike for a while since my seat was 'way out of adjustment. I'd finally remembered that I actually own a set of hex wrenches and could fix it. Yay tools.
I programmed the nixies to display "7 4 1776" and, by their flickering red glow, tried to figure out why their glow flickers. (
This plot was the key insight: the mains-derived supply voltage is one of the inputs to the software control loop… can you see what's going on?)