There are different file formats and ways to organize and save the files. In example those Dreamcast Roms on RetroAchievement expect the format from Redump.org group. That is a multi file structure with .cue and .bin files. Then I guess you have to compare the checksum to the first .bin file, but I’m not entirely sure, because the linked page does not clear this up. You maybe have gotten the files in .chd format? (BTW this is the format I prefer too.) This basically converts all .cue and .bin files of a disk into a single file format. But you would need the other previously discussed format.
So with the methods we have here its not sufficient just to check with MD5. This needs some extra tooling that specifically made to check Dreamcast files in Redump format. No wonder you were lost.
There are different file formats and ways to organize and save the files. In example those Dreamcast Roms on RetroAchievement expect the format from Redump.org group. That is a multi file structure with .cue and .bin files. Then I guess you have to compare the checksum to the first .bin file, but I’m not entirely sure, because the linked page does not clear this up. You maybe have gotten the files in .chd format? (BTW this is the format I prefer too.) This basically converts all .cue and .bin files of a disk into a single file format. But you would need the other previously discussed format.
I just tested this by comparing the checksum for “Shenmue (Europe) (En,Fr,De,Es) (Disc 1) (Track 1).bin” listed on Redump / Shenmue (Disc 1) as
9c6830264544845880e14fe64eb94193and it matches the first Track bin file. Normally this is how you would compare I think. HOWEVER it does not match any of the hashes listed on https://retroachievements.org/game/3398/hashes . According to their documentation the Dreamcast hashes aren’t MD5, but a custom hash that is no longer compatible with MD5: https://docs.retroachievements.org/developer-docs/game-identification.html#segaSo with the methods we have here its not sufficient just to check with MD5. This needs some extra tooling that specifically made to check Dreamcast files in Redump format. No wonder you were lost.