GB Studio / NESmaker / Genesisホームブリュー向けの無料レトロゲーム開発計算機。
Use when prototyping a homebrew retro game in GB Studio, NESmaker, or SGDK. Surface the budget problem before you build it.
Compiler error messages tell you after the fact. This tool warns you during planning.
Bytes used ≈ tiles × 16 + maps × 1024 + audio tracks × 4096 + code × 4. A coarse but useful planning estimate.
Each system has a fixed ROM capacity — Game Boy 32 KB, NES 128 KB, SNES 1 MB, Genesis 4 MB.
Above the ceiling? Bank-switch your tilesets or compress your audio.
Tiles × 16 bytes, maps × 1 KB, audio × 4 KB, code × 4 bytes/line. It's a planning estimate, not a compiled-binary calculation.
Game Boy VRAM holds ~384 tiles. Above that, you must bank-swap or share tilesets across screens.
Older cartridge systems split ROM into fixed-size banks (often 8KB or 16KB), and code or graphics cannot freely cross a boundary without bank-switching logic. The warning flags when your content is about to overflow the current bank.
Original Game Boy and NES cartridges commonly ranged from 32KB up to a few hundred KB, while Genesis cartridges scaled into several megabytes. Homebrew tools like GB Studio often impose tighter limits than the hardware maximum.
入力
Game Boy (32 KB), 200 tiles, 8 maps, 6 audio tracks, 500 lines of code.
出力
~37 KB used — over budget!
200 × 16 (tiles) + 8 × 1024 (maps) + 6 × 4096 (audio) + 500 × 4 (code) = 35,392 bytes — already over the 32 KB cartridge limit.