I have a set of No-Intro roms for NES and one for SNES.
Every one I tested so far runs with their related emulator (I’m trying Nestopia UE for NES)
Yet, if i try a file scan for any one of them nothing seems to be recognized.
is there a way to get a debugging or warning message somewhere in order to find out what’s going wrong?
Make sure the ROMs are not headerless, as sometimes they exist in headered and headerless forms. Also, iNES 1 vs iNES 2 header format might be important.
SNES ROMs should be headerless, but yeah, NES ones you want headers (they’re needed for the emulator to know how to handle the cart hardware)
Pardon me, but this is news to me.
How can I check this headerless state and, in case, can I correct it?
You can check a few of your games using a tool like this:
If you have a non-headered set, you may be able to use that tool to add headers in bulk, but I’m not sure. If not, you might want to just look for a headered set.
Also, Mesen can handle non-headered NES ROMs. Course that won’t matter for scanning unless there is a non-headered NES database.
Thank everybody for the help.
I managed to get a “headered” zipped set of NES roms and they are correctly scanned by Retroarch.
I have some questions, though.
After I scan a file, it’s correctly added to the “Nintendo Entertainment System” playlist, but if I select it and click “Run” I’m prompted to download a core to run it, even though Nestopia is installed and can actually run the rom. Could this be because the roms are zipped?
I tried then a manual scan of the whole folder setting it to default to the Nestopia core and “scan inside archive” as ON. All games (I think) were recognized and are runnable. Playlist image scanning does not work.
Database of RetroArch is non-headered IIRC.
Tested today with Zoda's Revenge - StarTropics II (USA).zip
Headered = not added
Non-Headered = added
My last experience seem to demonstrate the opposite.
Maybe there’s something that eludes us.
crc32:
f8e6f5c8 Zoda's Revenge - StarTropics II (USA).nes #headered
d054ffb0 Zoda's Revenge - StarTropics II (USA).nes #non_headered
https://datomatic.no-intro.org/index.php?page=show_record&s=45&n=2103
https://forum.no-intro.org/viewtopic.php?f=2&t=2979
No-Intro has therefore taken the position of removing headers on NES ROMs.
headered << 2017 >> non-headered
I don’t think I got what your post is supposed to mean.
Should I use headerless roms only since Retroarch 1.8.5 is newer that 2017’
So how come I’m able to scan headered zipped rooms correctly and not headerless?
BTW, I managed to find a database brower in Retroarch but it does not show CRC codes.
Main Menu - Information - Database Manager
Have you by chance enabled Main Menu - Settings - Playlists - Fuzzy archive matching? Otherwise i don’t know why headered rom scanning is working…
I only pointed out, that beginning with 2017 (i haven’t found the exact date) the no-intro team has decided to make only dat’s for non-headered nes roms.
Since RetroArchs database is build on the no-intro dat’s the scanner is searching for non-headered roms (checksums).
This is only for adding them to a playlist.
The emulators (cores) are working different (see mesen [headered and non-headered] and nestopia [only headered])
You can scan a non-headered rom an replace it after the scan process with a non-headered to make it easy.
I went to Main Menu -> information -> Database Manager -> Nintendo - Nintendo Entertainment System but I don’t see any CRC information shown there. I updated all downloadable content multiple times.
Strange…
I also tested multiple times to scan my headered rom, but it won’t get added to a playlist…
Sorry for not being able to help 
I never used NESHead before, but doesn’t this mean that CRC d054ffb0 is the HEADERED rom and not the opposite?
It doesn’t ask you to download a core, it asks you to select the core you want to use. This happens when you have more than one core that can load the ROM. It will remember the choice for each ROM. But if you load a ROM for the first time, it will ask you.
To set the whole playlist to always use Nestopia without asking you, go to Settings/Playlists/Playlist Management, select the playlist you want to tweak, and in there you can set the default core you want to use for all entries of the playlist.
Don’t let you fool by the crc in NESHead. It shows always the crc without the header.
A non-headered rom can’t be loaded in NESHead (invalid file error):
[UPDATE]
RetroArch database has both roms (headered and non-headered)
But my headered Zoda's Revenge - StarTropics II (USA).zip has the wrong checksum.
For this i wasn’t able to scan it.
Sorry for this
No, it ACTUALLY asked me do download a core.
If I clicked on download core and selected nestopia, Retroarch complained that I had already installed it.
Now i can’t replicate it because I deleted the playlist.
One question. Should i use zipped or unzipped .nes roms?
Now it seems that roms from the last headered set I downloaded are recognized fine and I’m keeping them zipped.
The non-headered set I found before had *.bin files inside the zip. That maybe could be the reason they were not recognized.
Whet i still don’t get it is: I indstalled another NES core (Mesen) for testinga setup with multiple cores and sometimes it asks me to choose between Nestopia and Mesen. Sometimes it only lists Nestopia as a choicke when I click Run. i thought the database was “shared” for all cores in a system,
zip is fine. I think even 7z should work 
Do you start your games through the Load Content dialog?
Which game for example?
