I need a few disposable firewalls to try something, and I have some 2200s and an R82 ISOmorphic drive sitting around. R81.20 gave me trouble on them earlier (missing storage driver, I think), so I thought surely R82 wouldn't actually work. Still, I had a little time to let something cook during a meeting, so I tried using the existing drive rather than reimaging the drive with R81.10.
THIS DEFINITELY ISN'T SUPPORTED, but apparently R82 will install and run on a 2200! If you manage to find a box with a permanent license still in the User Center, it could be a good way to keep a standing box around to try stuff without a constant stream of evals.