Famicom World

Family Computer => Technical & Repair Assistance => Topic started by: JessicaWolf on January 21, 2014, 01:18:02 pm

Title: FDSloadr "This is not an authentic FDS image"
Post by: JessicaWolf on January 21, 2014, 01:18:02 pm
So, I got myself a (free) laptop running Windows 95 just for the purpose of using FDSLoadr.

However, I continue to get the message "This is not an authentic FDS image" when trying to load images.

I can't seem to find a clear answer as to how to solve this issue. Can anyone offer any insight?
Title: Re: FDSloadr "This is not an authentic FDS image"
Post by: Issun on January 21, 2014, 01:37:43 pm
I think the FDS images need to have a 16 byte header for FDSLoadr to load them, so check your images. If they don't have one, you can add one via an hex-editor, the format can be found here: http://wiki.nesdev.com/w/index.php/Family_Computer_Disk_System
Title: Re: FDSloadr "This is not an authentic FDS image"
Post by: JessicaWolf on January 21, 2014, 06:02:54 pm
Ok, after fooling with it for a couple hours, and trying to fully understand everything, I just don't think I get it. Is there anyone out there who could offer help. The game I am trying to work with is Metroid (version 1.1), since I already own a copy but it just needs to be rewritten. Is there anyone who could so me an example of a proper header for this game?
Title: Re: FDSloadr "This is not an authentic FDS image"
Post by: kiwidaveinjapan on January 21, 2014, 06:32:21 pm
So, I'm actually sending you a copy of Metroid with the twin I posted you... :D

Did you read the guide attached to the bottom of my post in the "how to" question you posted? it shows how to edit the header.

Hope this helps.
Title: Re: FDSloadr "This is not an authentic FDS image"
Post by: JessicaWolf on January 21, 2014, 06:46:53 pm
I believe I have done that already, but maybe I did it in the wrong place?

Spoiler
(http://i.imgur.com/6EUVWIU.png)
[close]
Title: Re: FDSloadr "This is not an authentic FDS image"
Post by: ericj on January 21, 2014, 06:51:00 pm
That disk image is missing the header.
Title: Re: FDSloadr "This is not an authentic FDS image"
Post by: JessicaWolf on January 21, 2014, 07:27:25 pm
Is there anyone out there who could show me the proper header info for this disk?

I am not the best at reading this kind of code and such, but once I see it I can understand it much better.
Title: Re: FDSloadr "This is not an authentic FDS image"
Post by: ericj on January 21, 2014, 07:38:38 pm
Metroid should look like this:

(http://i275.photobucket.com/albums/jj287/pingaloquita/metroid_zpscbc4251c.jpg) (http://s275.photobucket.com/user/pingaloquita/media/metroid_zpscbc4251c.jpg.html)

What I usually do is open a good disk image with a hex editor, copy the header, and paste it into the file missing the header. The first line where you see 02 is for a 2-sided disk. Simply change this to 01 for a one-sided game.
Title: Re: FDSloadr "This is not an authentic FDS image"
Post by: JessicaWolf on January 21, 2014, 07:46:57 pm
You are amazing ericj, now I see where I screwed up and what you meant by there being no header.

Just out of curiosity, why does the header not get dumped when dumping a disk?

EDIT: Also, if it loads properly in an emulator, that means I did everything properly, right?
Title: Re: FDSloadr "This is not an authentic FDS image"
Post by: Issun on January 22, 2014, 03:35:51 am
Quote from: JessicaWolf on January 21, 2014, 07:46:57 pm
Just out of curiosity, why does the header not get dumped when dumping a disk?


Because that 16 byte header is not on the disk. It's just part of the FDS file format.