I have a pair of Atari Portfolios' in my retro collection, one of which is my original from the release, and the other was a contribution - and they're simply delightful little machines.

My original still has Turbo C on it, and all the programs I wrote during flights all over the place back in the 90's, keeping myself awake in obscure airports.

Very fun to dig it out, put in fresh batteries, and go back to where I was editing, ~30 years ago .. ;)

My GPD Pocket is still a better dev machine in that regard, though..

(I also have an Olivetti M10, which is like a Tandy Model 100 .. another delightful machine with saved state that goes back decades, instantly available with the insertion of a couple of ol' trusty AA's ..)