I recently downloaded the ROM set for MAME 0.217 (non-merged). It's the first time in probably 10+ years I've "updated" and I'm wondering if there is a way to tell which version of a ROM to use? For example, 1941 has several ROMs associated with it:
1941.zip
1941j.zip
1941r1.zip
1941u.zip
I know "j" is for Japan, "u" is for USA and I think "r1" is for Revision 1 (or maybe Russia, Japan & Korea?). I assume the plain name "1941.zip" is the "World" version and is the one I should use.
But what about ROMs with "a" or "a1" which usually indicate alternate versions with bug fixes? For example, should I use "1942.zip" or "1942a.zip"? Just wondering how you guys sort this all out.
Thanks.