I guess technically that'd be Arthur rather than RISC OS.
My high school had a particularly well connected compsci teacher who managed to get his hands on one of the first Archimedes to be sold (using his own money it must be said ...). At that stage it shipped with Arthur because, or so we were told, the "actual" OS was still in development. As it turned out, that OS was eventually cancelled and instead Arthur was upgraded (in practice ... replaced by) RISC OS.
I still have fond memories of playing the demo that would become Zarch (aka "Virus" on the Amiga/ST/Spectrum/etc.).
Yep, I think of Arthur as a sortof Beta for RiscOS
I had an Archimedes A305 which launched with Arthur, when I upgraded to Risc OS (which arrived on ROMs, if I remember correctly, you ordered the ROMs and then your local dealer would fit them onto the motherboard) it wasn't really _that_ different, everything I'd written continued to work, etc. Like it was a major upgrade but fundamentally the same "thing".
I had that same model, except I fitted the chips myself. The first time I’d really ever looked inside a computer and very exciting for me age 11. The old Arthur ROMs were a prize possession for quite some time afterwards.
I could come back to the "modernising RISC OS" piece and update, as things are now actually happening. Although I was pessimistic for its prospects, it's becoming reality.
I know of 2 main efforts...
* Merlin, an all-new OS in Rust, aiming for a very simplified modern design and backwards compatibility.
* The RISC OS Open team is rewriting it in C.
I also know of an effort involving running an Arm64 hypervisor and then running the current 32-bit RISC OS kernel in a whole-machine VM. I lack any tech details about it so far, though.
My high school had a particularly well connected compsci teacher who managed to get his hands on one of the first Archimedes to be sold (using his own money it must be said ...). At that stage it shipped with Arthur because, or so we were told, the "actual" OS was still in development. As it turned out, that OS was eventually cancelled and instead Arthur was upgraded (in practice ... replaced by) RISC OS.
I still have fond memories of playing the demo that would become Zarch (aka "Virus" on the Amiga/ST/Spectrum/etc.).