Question About ROM Size

So is there a limit to how much I can add to a firered rom? Like if I double to size of every map and give every trainer 6 pokemon hypothetically, am I going to run out of space or will the compiler handle this issue for me?

HarveySlayer said:

So is there a limit to how much I can add to a firered rom? Like if I double to size of every map and give every trainer 6 pokemon hypothetically, am I going to run out of space or will the compiler handle this issue for me?

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Rom size is normally limited to 32 megabytes. Maps and trainers don't use a whole lot of space so you would need to add a LOT of those before you would even get close to running out of space. Audio and graphics is what usually takes the most space.

So if I am not adding any sounds or graphics, I will be fine? What will the error be if the rom does end up being to large?

HarveySlayer said:

So if I am not adding any sounds or graphics, I will be fine? What will the error be if the rom does end up being to large?

Click to expand...

If you don't modify anything, the ROM won't get bigger

This is the reason for the 32MB limit：
08000000-09FFFFFF Game Pak ROM/FlashROM (max 32MB) - Wait State 0
0A000000-0BFFFFFF Game Pak ROM/FlashROM (max 32MB) - Wait State 1
0C000000-0DFFFFFF Game Pak ROM/FlashROM (max 32MB) - Wait State 2
0E000000-0E00FFFF Game Pak SRAM (max 64 KBytes) - 8bit Bus width

So the ROM size is just determined by a couple lines of code?

HarveySlayer said:

So if I am not adding any sounds or graphics, I will be fine? What will the error be if the rom does end up being to large?

Click to expand...

You will be fine as long as your changes don't add more than ~23 megabytes of new data to the rom, regardless of what that data actually is. So you could run out of space even without adding new graphics or music, but it is a lot less likely.

Even if you do add graphics and music, it's still not very likely that you would run out of space. And that's why you shouldn't really have to worry about rom space, unless your compiled rom is starting to get close to 32mb in size.
I'm not sure what error you would get if that did happen, but you would likely run into something like this way before that, luckily it can be fixed easily.

Wow, 32 mb is a lot bigger than I first realized