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 Post subject: Checking ROM headers
PostPosted: Fri Feb 28, 2014 3:08 am 
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Is there an easy way to check if the headers in NES files are correct? It's really tedious to check the several byte values against the data for example in the Bootgod database.
So, if there isn't a program that can correct the header automatically per ROM, is there at least a list of the "original" headers for each game, so that I can compare the values 1:1?

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 Post subject: Re: Checking ROM headers
PostPosted: Fri Feb 28, 2014 7:08 am 
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There's no such thing as original headers because the headers are not a part of the ROM dumps themselves; they're entirely our invention.

There are a lot of "header cleaner" programs out there which operate in various wonderful ways, but I doubt most of them are very accurate. What's so bad about using bootgod anyway?


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 Post subject: Re: Checking ROM headers
PostPosted: Fri Feb 28, 2014 8:22 am 
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Yeah, I know that the headers aren't part of the original ROM. But that doesn't change the fact that there are right and wrong headers, right? I mean, the real world physical "Super Mario Bros." cartridge is set to vertical mirroring. If the header in the ROM file has the value for horizontal mirroring, then the header is obviously wrong. Not wrong from a purely technical point of view, but wrong in relation to the real cartridge.

I guess general cleaning (for example replacing the string "DISKDUDE" with zero values) wouldn't be enough here. The tool would need to know the actual data for each specific game.

Using Bootgod isn't bad per se. It's more the general dislike of having to manually go through a bunch of ROMs and check their headers. Especially if you're not that fluent in headers and the Bootgod website merely provides the human-readable data. You have to convert it in your mind: "O.k., the game has horizontal mirroring. What values was that again? Zero or one? Oh yeah, zero. Alright, next value: What was that byte good for again? I have to check the documentation again." You know what I mean? It's tedious and error-prone.

There is a program that helps you to find out which ROMs you have, renaming them. I.e. the program knows the hash value of every ROM in existance. Why isn't there a similar program for fixing the header? If GoodNES can find out that your "smb.nes" is "Super Mario Bros. (JU) (No Title Hack)", why isn't there a program that can tell you that the header in your file doesn't correspond to what the game really was like?

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 Post subject: Re: Checking ROM headers
PostPosted: Fri Feb 28, 2014 8:44 am 
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I agree that there are right and wrong headers, as we've defined them. I was just taking exception to your use of the word "original."

There's absolutely nothing stopping a bootgod backed header cleaning application from being created; it just hasn't been done yet (to my knowledge).

You CAN use the goodnes data to fix headers, and there is a program that does this already. I'm not terribly familiar with the internals of goodnes, but look for something called "fixnes"? The goodnes data is not as accurate as more current bootgod data; but it encompasses more things than bootgod does.


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 Post subject: Re: Checking ROM headers
PostPosted: Fri Feb 28, 2014 12:11 pm 
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Because nobody has written one. I could, but I'm busy with other projects.


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 Post subject: Re: Checking ROM headers
PostPosted: Sat Mar 01, 2014 2:20 am 
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tepples wrote:
I could, but I'm busy with other projects.

For me, a list of all the headers written in a specific format would be enough already. Do you have something like that? (Because otherwise, having no time to write a program would be the least problem. I guess having no time to manually write down the header data of 1000+ games would be much more of an issue.)

If you can send me the header data in any format or tell me where to find it, I might write such a tool.

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Trailer: https://youtu.be/IYXpP59qSxA
Gameplay: https://youtu.be/Eee0yurkIW4
German Retro Gamer article: http://i67.tinypic.com/345o108.jpg


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