Cheap Chromebooks work well for this, as long as they're among the models that can be jailbroken and take a proper Linux install. Ample power to run a text editor and a textmode browser (Emacs and eww, or any other, lesser, choice you may prefer), but not enough for graphical browsing and other distractions. Too, since they're specced to run Chrome for a couple hours, you can easily get 8 to 10 hours of battery life running something less absurd.
The keyboards aren't what you call great, but they serve well enough. I like a mechanical keyboard as much as the next dork, but I've never really felt the lack when using the Chromebook for writing.
> Cheap Chromebooks work well for this, as long as they're among the models that can be jailbroken and take a proper Linux install.
Jailbreaking Chromebooks is a huge hassle, though. Much easier to install Linux on a standard box from the past 10 to 15 years. You can also buy cheap low-end hardware with Chromebooks-like specs that will run Linux out of the box.
The keyboards aren't what you call great, but they serve well enough. I like a mechanical keyboard as much as the next dork, but I've never really felt the lack when using the Chromebook for writing.