Since we do not have native C compilers on the Oric, this forum will be mostly be used by people using CC65 or the OSDK. But any general C related post will be welcome !
Ok, I'm looking at the docs for the OSDK and it lists 44 bytes of page zero reserved starting at $50. Is this info up to date and is it safe to use bytes after that?
Until to a certain point, yes.
I believe that from $9a starts some BASIC related variables.
You can find a (partial) list of used system variables in the Oric Atmos manual, in the Annexe 9.