johnodon you need to customize the es_systems.cfg file for various systems on one !!
EXAMPLE
i wanna add more emus on one same weel .
i will copy the code from the base emu .
and i will sztart with dreamcast ,
<system>
<fullname>Dreamcast</fullname>
<name>dreamcast</name>
<path>/recalbox/share/roms/dreamcast</path>
<extension>.cdi .CDI .chd .CHD .gdi .GDI</extension>
<command>python /usr/lib/python2.7/site-packages/configgen/emulatorlauncher.py %CONTROLLERSCONFIG% -system %SYSTEM% -rom %ROM% -emulator %EMULATOR% -core %CORE% -ratio %RATIO%</command>
<platform>dreamcast</platform>
<theme>dreamcast</theme>
<emulators>
<emulator name="libretro">
<cores>
<core>reicast</core>
</cores>
</emulator>
<emulator name="reicast">
<cores>
<core>reicast</core>
</cores>
</emulator>
</emulators>
</system>
now i wanna add more cores from diferents systems on that base system from dreamcast .
just copy the cores you want like this .
<core>fba</core>
<core>dolphin-emu</core>
<core>genesisplusgx</core>
and whatever you want .
after that you need to change some configs on your code like change the names and woul be like this .
<system>
<fullname>Mixed systems</fullname>
<name>Mixed</name>
<path>/recalbox/share/roms/mixedsystems</path>
<extension>.cdi .CDI .chd .CHD .gdi .GDI</extension>
<command>python /usr/lib/python2.7/site-packages/configgen/emulatorlauncher.py %CONTROLLERSCONFIG% -system %SYSTEM% -rom %ROM% -emulator %EMULATOR% -core %CORE% -ratio %RATIO%</command>
<platform>various</platform>
<theme>multysystems</theme>
<emulators>
<emulator name="libretro">
<cores>
<core>reicast</core>
</cores>
</emulator>
<emulator name="reicast">
<cores>
<core>reicast</core>
<core>fba</core>
<core>dolphin-emu</core>
<core>genesisplusgx</core>
</cores>
</emulator>
</emulators>
</system>
if you see the code above and edited now its multi systems i could play that systems i already add the cores .
for extensions you need add the extensions from all platforms games .
You need create a theme for you own multy systems ..
create a rom folder and add the games from all systems you want remix togheter .
just go to theme and duplicate another theme change the name to multi systems and create your own screens for that system based from one already exist ,..
ADVICE - this is a example to explain how to mix systems . if you get some error after editing some systems you need to watch for error code on es_systems.cfg
i will make a video about this .
