Earlier quoted context omitted.
I have an Android ADP1 --- one of the original development phones, the HTC Dream with the custom paint job. It's got 192MB of RAM and a single-core 528MB ARM11. It ran Cupcake, aka Android 1.5 (although I've since upgraded it to, If you ignore the hilarious security bugs --- like the fact that, as shipped, they forgot to disconnect the keyboard from a root shell, so that if you typed 'reboot' into an email hilarious…
I also had ADP1 - and I think that the latest official update was to Donut, aka Android 1.6. Not that it matters much today...
Unfortunately its https library uses some obsolete crypto technique --- TLS 2? --- and as a result it can't connect to anything on the internet, not even to fetch updates from the App Market (not the Play Store!). I can't even log in to Google.
I did have Gingerbread on it at one point but it was very unhappy.
I found a partial Debian port but there's still not really enough RAM for that. I wonder if there's a NetBSD port...