Once in Internet I found photos of giant soviet panel named IGG1 (ИГГ1). It was looking stunning!
This panel made in two versions:
IGG1–32x32 with 32x32 dots resolution
IGG1–64x64 with 64x64 dots resolution
Some technical data:
Brighntness: 150–300 kd\m2;
Minimal anode voltage: 210–240v;
Working voltage: 400v
Working voltage range: 370–420v
Current per dot: 25 uA;
Refresh frequency: 1000 Hz;
Maximum cathode duty cycle: 64;
Anode duty cycle: 32;
Weight: about 1 kilo.
64 version have two alternates dots colors: green and orange
Made at late 1980x — beginning 1990x at “Gazotron” factory (Rivne, Ukraine)
Today I got one IGG-64 for test. Maybe do some table clock with Wi-Fi sync:)
On photos it looks more smaller than in real life.
Compare with Arduino board
Compare with iPhone 6S