Ds: Pack Roms Nintendo

When a DS game was manufactured, the ROM size had to match a standard mask ROM size (e.g., 128MB, 256MB, 512MB). Often, the actual game data was smaller than the cart's capacity. The remaining space was filled with "garbage data" (0xFF or 0x00).

You can legally build your own "pack" from:

This is true packing. Unlike trimming, compression doesn't delete data; it rewrites it mathematically to take less space.