Upgrading a Raspberry Pi

So I have a Raspberry Pi running RISC OS which I have been happily tinkering with for the past few months. (Having not used RISC OS since owning a Risc PC in my “youth”, it’s interesting how much has changed in RISC OS – and how much hasn’t.)

I looked on riscosopen.org recently and I see that the most recent release of RISC OS for the Raspberry Pi is “RC12”. I understand that RISC OS is distributed in two “components”, the ROM itself and the HardDisc4 contents, which are bundled together to make a card image for the Pi. I therefore have a few questions:

1. How do I tell which “RC” version of RISC OS is currently running on my Pi?
2. Is there anywhere I can tell what has changed between different “RC” versions?
3. Is it possible to upgrade my Raspberry Pi to a new RC release without re-flashing the card?

3. simply put the new rom (available on this website) in the fat part of the sd card.

RC12 (the SD card image) includes (i) the HardDisc4 image; (ii) some extra software and (iii) the RC12 rom.

To upgrade to RC12 (the SD card image) you need to reflash the SD card. To upgrade to RC12 (the ROM), you can change the rom (within !Boot.Loader) but this will only work if you are already at RISC OS 5.2×.