Okay, good to know about the dat files. Explains a lot.

I think I originally did it when I was playing with Lazarus. Can't remember now though.
The catver.ini files seems to work fine. Not sure if I can make a filtered list based on it though. Haven't gotten that far.
Yeah, the rom naming sucks. I originally had them how you described, but then I was playing with using DOS 6.22 and it didn't support the long filenames. So, I changed them to what they are now. Too much work to put them back, so I'll live with them. Not like I'm going to get more Atari roms anyway

Thanks for the feedback though.