You can find all the necessary information for making a rom in the Section 10 of the [[Soft968:_CPC_464/664/6128_Firmware|firmware guide]].
And For technical discussion we have [http://www.cpcwiki.eu/forum/programming/16kb-rom-game-compo-technical-thread/ this thread] in the forum for technical discussion, where you can ask for help and find nice tips ([https://github.com/Octoate/cpc-sdcc-rom how to code your rom in c] by Octoate) and ask for help.
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