Arc Linux just about runs.
I've still got a modded A440 c/w SCSI + ethernet, ARM3 + VIDC enhancer. Luckily my then employer bought it for me and upgraded it over the years for me. For its time, it wasn't too bad, but they should have bought me the R260 to donk with.
Last time I powered it up, it offered RISC/OS3.1 or Acorns slobberingly shit version of Unix.
After much fannying about, I got a shell prompt, thought fuck it and put it back in the loft. The big PITA on that class of Arc is the useless floppy disc drive.
Linux on a RiscPC or later is not too bad, but compared to even a low end Pentium is shit slow.
( moonbadger Doesn't judge a fish by its ability to climb trees, Sat 10 Sep 2011, 18:27, 1 reply)

The A310 has RiscOS 2 ROMs, not 3. That might be a good start.
( Ungersven would support SpankyHanky's patreon, Sun 11 Sep 2011, 12:58, closed)