Once you have it compiled and running in the places you want it to be adding new systems will be easy. Basically you just add a new line at the bottom
addSystem 0 "$md_id" "mame-advmess arcade mame" "$md_inst/bin/advmess %BASENAME%"
the addSystem function assumes the system is listed in platforms.cfg. if not it needs to be either added or you can use the setESSystem function like so:
setESSystem 'Kodi' 'kodi' '~/RetroPie/roms/kodi' '.sh .SH' '%ROM%' 'pc' 'kodi'
Where the 7 (soon to be 8 with direct launch tag) are listed in this order: Full Name, name, rompath, Extensions, launch command, platform, theme.
Then Once you have added your system and you don’t want to compile advmess again just so you can configure a system you can type:
cd RetroPie-Setup sudo ./retropie_packages.sh advmess configure
And it should configure the proper launch options (for each system you’ll also likely need to add its rom folder with mkdir <romfolder> in the configure function. Because of how many specific launch options there are with advmess its likely we’d have to do something similar to vice so that even though they are basically the same emulator we treat each game type as it its a different system.
I wonder what I should do to get support for the BBC B Plus, BBC Master and Master Compact?
Is it enough just copying the appropriate romsets or these models should be installed as separate systems?