alt Hacker NewsBlock mode terminals are somewhat similar to the forms based UIs we later got like HTML.
The 3290 was like a 4 split tmux session, it is such a beautiful device (https://ifdesign.com/en/winner-ranking/project/ibm-3290-info...). Perfect keyboard, plasma contrast and the right text color for long sessions. My understanding is they outlived themselves with long service in air traffic control (supplementing vector/raster displays), financial markets, and software development. Once upon a time people seemed to really care about doing things well.
IBM terminals were the original stateless clients. :)
I had a PS/2 Portable 70 for a while. It was a luggable Microchannel PC with a orange plasma display. Going through airports with it was a hassle as it didn't have batteries - I would have to find an outlet to power it on for airport security inspection.