There is now a new directory 'system' (USRDIR/cores/system) where most libretro cores will search for BIOS files and such. You need to put the BIOS files there.They have to be named a specific way - same filenames as for Genesis Plus GX on Wii -
The BRAM file (Battery backup RAM) will be created for you in that same system directory as well.
All bios files need to be placed in /dev_hdd0/game/SSNE10000/USRDIR/cores/system
For Sega CD the bios files must be named **EXACTLY** like listed below
As of right now I've only tested 2 bios files from the No-Intro set. The first is 1.00 which is the very first model and the second is 2.11X which is from the very last model. Don't ask where to get them from and I won't have to BS you. Google is your friend
Unfortunately, CD Audio Track support is not working 100%. I loaded Sonic CD and can play the game flawlessly, but the soundtrack does not play. I will check other games later tonight. It could be related to the PREGAP line in the CUE sheet. Not all games will use that line.
It has been suggested that loading BIN/CUE files by selecting the CUE file will break the emulator causing you to need to reinstall. I have not run into that problem yet. I believe it's due to the CUE sheet containing a line at the very top containing the word CATALOG. Some programs add this line but it is completely unnecessary. Make sure your CUE file contains only lines starting with FILE, PREGAP, TRACK, or INDEX. You can edit it with any text editor like notepad. You should also make sure that the file line points to the **EXACT** name of the BIN file. Case is important!!