no-intro dumps and preserves the game ROM itself and stores information like a checksum and serial number etc of the game. Headers are not their work and are completely ignored by tools like Romcenter because these are NOT meant to be there at all in radical preservation metters. It's hand made additional stuff only needed for emulators. This was already discussed on SNES, but there they are even more useless.
Licensed SNES games have their own built-in header, but this header does not identify all the special chips that were used. The games which use a special chip are known and finite. The games that require more specifity only number 15-18. The internal header gives the ROM size, the RAM size and whether it needs HiROM or LoROM mapping and whether it uses FastROM or SlowROM. This is sufficient for 98% of games.
The Gameboy and Gameboy Color ROMs also have an internal header, which gives the ROM & RAM sizes and the MBC mapper the game uses, if any. It can also tell you if the game requires a RTC or supports the Rumble Pak.
When it comes to the N64 and the GBA, there is a header but it does not tell you what the save type of the game is (sram, flash, eeprom) or what CIC the cart uses (N64 only). But that information is known and can be stored in a database.
But when almost all NES cartridges use a mapper chip, you need to know what mapper it uses, otherwise it won't run. You also need to know if there is CHR-ROM and how much there is and whether the cartridge uses S-RAM. Otherwise you can't know how the game works, and if you don't know that, then you haven't preserved the game.
