330
Amazon: Older Kindles can no longer download e-books
(www.heise.de)
This is a most excellent place for technology news and articles.
Any Kobo can install KOReader with a minor firmware update (that only needs to be done once). There’s instructions here: https://github.com/koreader/koreader/wiki/Installation-on-Kobo-devices It supports OPDS out of the box (though IMO is a little unintuitive to use)