Hi! I have a related but slightly different question:
I want to load the current MAME Retroarch core (if possible from Launchbox) but using a MAME specific command line parameter (which is different than a retroarch core option command line parameter), in my case -lowlatency. When loading mame without retroarch it would be:
mame insert_here_the_zip_rom_name -lowlatency
I mean, this parameter wouldn’t be one of the Retroarch command line parameters used for different cores. It’s a MAME (current MAME) specific command line parameter. I tried to introduce lowlatency = “true” in the config/mame/mame.cfg file, or mame_lowlatency = “enabled” in the config/mame/mame.opt file but doesn’t seem to work.
To see if it worked or not, while running a MAME game you can go its menu by pressing insert coin+start buttons (by default select+start in a pad/stick) then to go to “configure options” > “advanced options” and you’ll see in the “low latency” disabled inside the “performance options”. Which btw for some reason if you enable it and select “Save Configuration” there doesn’t seem to remain saved anywhere after you quit the game.
Is there any way to include a MAME specific command like parameter like -lowlatency when calling Retroarch? Or a way to include it on a .ini/.cfg/.opt file? On the normal standalone MAME (the one outside retroarch) it’s stored on an .ini file, so I enable it there every time I run that standalone mame it runs enabled.