Long, long ago, Tunnel Diodes were going to usher in an era of ultra-fast computing because their negative resistance region allowed for current gain in the sim

Long, long ago, Tunnel Diodes were going to usher in an era of ultra-fast computing because their negative resistance region allowed for current gain in the simple 2 pin device. It didn't work out for most of it, but does show that you can do logic without transistors. Think of these as incredibly slow negative resistance devices. Computing with them might be possible, barely. But sometimes that's all you need.