@codinghorror said in Advmame emulator not showing up in RetroPie 4.0.2?:
(Is there a good reason not to use advmame? I prefer it for vector games and the like?)
We generally prefer RetroArch cores for their ease of configuration. lr-mame2003 and lr-fba-next are a good compromise between a large ROM set and nice performance on Pi 2 and Pi 3. It's also easy to find the ROMs, search Google for "mame2003 reference set" or "fba 0.2.97.38 reference set".
However, AdvMame is the only way to play vector games smoothly.
If you put ROMs in the mame-advmame directory and mame-libretro directory, you'll end up with two RetroPie menu entries called MAME which can be a bit confusing/messy. You can work around this by using the arcade directory for one type of ROM (say all your vector games in arcade and all other games in mame-libretro), or you can use a theme with different AdvMame/libretro-MAME header images.