Bak files

Anyone know what the difference is between .gba.bak and regular .gba files.

When I expanded my rom it created a .bak file. This is not good because it does not run in emulators like visual boy advance.

Also, when I expanded and added classes from 128 to 156, that version of my rom and all of the versions since then are glitchy. For some reason when I click on portrait editor or class animation manager in FEditor advance (FFFF indices) it does not load.

However animation creator and text editor still work. What is going on?

It’s a backup file. It’s created when you use HXD or some other hex editor, just in case the expansion kills your rom. You can either delete it, or if your rom is ruined, delete the new one, and rename the .bak file to just FILENAME.GBA and it will work perfectly.

After expanding, you need to open in FEditor, save it, close it, then re-open it. This updates the footer.

Brave’s suggestion fixed this but I want to make sure I expanded right.

According to Chocolate Kitty’s repointing tutorial on serenes forest when expanding items :

Hit replace all, and(in this instance), you’ll see a lot of replacements(62 should be how many in FE7).

That is a lot of replacements (62) for expanding items and changing the pointers. What I wondered was when I expanded classes I only made about 4 replacements in Hxd. That’s not a lot.

It didn’t crash but does that sound right for classes? Only 4?

Any time the item table is referred to in code it will use the pointer. The item table gets referred to a lot. It does sound about right, though I can’t remember exactly how many there were.

I’m pretty sure it’s 62 or 63. When I had this issue I had to start over serveral times and expanding the item table was always the first thing I did whne I started with a new rom.

Thanks but I meant does 4 changes sound right for classes (NOT items).

The class table is referred to a lot less than the item table - I believe there are only 4 references.

Can the gba.bak file cause the ROM to become glitchy? I never really knew what the file did until reading the original post right now. I always noticed that my .bak file size is different than my actual ROM file size.

Is this cause for concern? I’m only looking into this because my current version of my ROM is being glitchy as hell right now. The .bak file size is the same number as when my ROM was, when it was working more properly than it is now, so am I right to be afraid to do the open FEditor, save, and reopen?

Does save files have anything to do with the .bak files as well? If the original post is right, if I somehow revert back to the previous “version” that is saved to the .bak file, will my current save file work with the ROM? I’m asking this because l’ve been using save files, that are from a way older version of my ROM, with the most current version of my ROM as I make changes to my hack.

.bak files are just backups that are created when you use HxD (other programs might create them too, but I know for sure HxD does). Their filename should be in the form of “filename.gba.bak” if it’s a backup of a GBA ROM. If you remove the .bak extension, it becomes a .gba and can be run in an emulator.
If the sizes are different, compare the date that each file was last modified. The .bak is likely just an older version of the ROM.
Save files don’t have anything to do with .baks.

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