#riscos is complicated.
I'm running 5.24, the current stable version on a Pi2.
One of the 26bit sort-of-emulators, #ADFFS, now requires RO 5.27, a beta OS version.
They didn't mention this new requirement... until after I'd upgraded.
For some reason, it was not simply a matter of reinstalling the old version, as the old versions also refused to work!
After a lot of crashes I replaced the CMOS file with one from a stock RO5.24 image and got ADFFS 2.64 to work again. stopping cuz it works.
It's pure BASIC so I thought it would run under regular 32bit RISC OS, but nope, turns out it pokes directly at the old Acorn video chip.
I was able to figure out how to make it work under #ADFFS and I'm proud of that.
"I appreciate SDF but it's a general-purpose server and the name doesn't make it obvious that it's about art." - Eugen Rochko