If you are new to RISC OS you should read Introduction to RISC OS.
The download link provides a copy of the PineA64 (Pinebook) development ROM image. It is a bleeding-edge build which comes from the latest revisions of all the relevant sources in our source code repository and is completely untested.
Using this ROM image in your computer should only be done if you are confident that you know what you are doing! It is likely to be functionally incomplete and probably unstable in various ways.
Although a copy of SDCreate is included in the download, it does not currently have any support for the PineA64.
The PineA64 doesn’t have CMOS memory on the circuit board which RISC OS expects to find to hold its essential configuration options needed before the main !Boot application is run.
Some default values are ‘hard coded’ into the ROM image and these will be used at every power on. It isn’t currently possible to seed the CMOS settings with your own.