@mitu The problem I was having with Win32DiskImager was getting an error dialog box when trying to open the SD card device. It was a "cannot lock volume" error.
Turns out this is a big problem with Windows (10 in my case). Some applications (typically music players or photo catalogers) traverse the file system looking for things and can have things open on your "boot" drive letter so you can't use it.
I was finally able to get it to work using a fresh laptop machine. So if you have this problem you might be able to find out who has files open on your SD card using Microsoft's "process explorer" program and close that program or be forced to another Windows instance.
I'm doing testing with my "dd" idea now that I have media I can experiment with.
That's a very nice trick. Until now, I was under the impression that AdvanceMAME was the only arcade emulator where the BIOS files and clones could reside away from a main ROM grouping. Thanks for sharing this.
@battlecat One way to do this would be to do the following:
Scrape all of your roms to make sure all are listed in the gamelist.xml file.
Manually edit the gamelist.xml file (usually located in ~/.emulationstation/gamelists/<system>) to remove the unwanted roms.
From the main emulationstation screen, push start, then find the option in the menu that says "Parse gamelist.xml file only" or something like that.
Reboot your system, then enjoy!
This is how I hide the various bios files as well. Of note, if you add a new system or rom, you'll have to disable the "Parse gamelist.xml" option to see the new roms, unless you've scraped them already.