Questions about EverDrive N8 (Pro) and headered/unheadered files.

[MustardBubbles]

I'm updating my no-intro romset for my new N8 Pro and I have both a headered and unheadered set.
Which set would I use, and why?
I also only have an unheadered set for the FDS. Will this set still work on the N8?

[P]

The header contains metadata that tells emulators and Everdrives what type of cartridge board/mapper the ROM was found on. This is information added by the dumper of the game, it isn't included in the ROM chip. Unheadered ROMs will not work on emulators or Everdrives, and I see no reason for having ROMs without the headers. They can always be removed when you don't need them (like when burning them on a PROM devcart).

There are two types of headers mainly used for Famicom ROMs. The iNES header (the classic one invented for the old emulator iNES) and the NES 2.0 header, which was made to solve problems and support more games than the old iNES header, and it's backwards compatible with iNES. Mesen allows you to see what header your ROM has using the "Edit iNES Header" option (you may need to enable the debug options in the settings to see it). Unheadered ROMs might not show up correctly here though.


The headers for FDS images are not strictly required because they only contain information of the number of disk sides the game spans (which can be deduced just by looking at the image size). Some emulators like Nintendulator refuses to load without a header, but neither the Everdrive nor the FDSStick requires it. Mesen also doesn't require it if I remember correctly.


Edit: Here is a NES 2.0 XML database containing all the known correct NES 2.0 headers for every licensed game and many unlicensed games. It was updated with data from the recent Nintendo leaks (only a few versions of some games were missing, all licensed games are dumped) so it should have all licensed games.
If you have a ROM that doesn't seem to work correctly, you can use this database to verify that all header fields are correct. Most of your ROMs probably uses iNES headers so not all fields are used though. Hopefully the Everdrive will add support for NES 2.0 headers in the future (if it hasn't already).