llopis diag ROM on a M4 board ?

[Deevee]

Hi !My "classic" 6128 stopped working a few weeks ago. I'd like to use llopis' dignostic ROM (https://github.com/llopis/amstrad-diagnostics) with a M4 board. I know this has been written to work with a Dandanator, but my attempt to get one of those only made me lose 40€ on a scam website. So I finally got an M4 board. The problem is I don't really know how ROMs work on a CPC (I'm learning though).
I have a working 6128+ on which I configured my M4, but I don't really understand how to put the diag ROM in it, in which slot it should go, what settings to use, so the ROM can take over the computer's one and start.
In other words, a quick step by step guide on how to set it up correctly would be very welcome
Thanks

[pelrun]

You'll want to upload the AmstradDiagLower.rom to basically any slot on the M4, although 31 is customary. Then make sure the LowerROM settings at the top of the ROM page are enabled and set to the slot you put the ROM in (i.e. 31). Then save the config and reboot the CPC.
All the other versions rely on at least some of the system firmware working in order to start them up, but the lower rom is the very first thing to run when the system powers on, so replacing it with the diag rom means there is zero need for any functioning RAM or ROM in the CPC to get the initial tests to run.

[Deevee]

Thanks for your answer, seems easier than I first thought