If using RetroArch, do not use the generic MAME core. Use MAME 2003-Plus or MAME 2003 Extreme . These are built specifically for the 0.78 ROM structure.
A "new" set is almost always . What does that mean? mame 078 rom set new
You can delete games you don't want without breaking others. If using RetroArch, do not use the generic MAME core
MAME 0.78 ROM set is a standardized collection of arcade game data files designed for use with If using RetroArch