kroy.CartTools - 0.9999.20260920.1

kroy Sep 20, 2026

openFPGA-CartTools

A cartridge utility core: identify, dump and back up Game Boy, Game Boy Color and Game Boy Advance cartridges through the Pocket’s cartridge slot, and dump Game Gear and Atari Lynx ROMs through the official Analogue adapters.

Derived from the Pocket GBA core by mincer_ray, itself a port of GBA_MiSTer. Licensed under GPL-2.0.

Save restore is alpha. It writes GB/GBC cartridge save RAM after identity and input checks, a verified recovery backup, and a deliberate confirmation. Restore is hardware-verified on Pokemon Silver (MBC3, 32 KiB), Dragon Warrior III (MBC5, 32 KiB) and Shadowgate Classic (MBC5, 8 KiB). MBC1 8 KiB and other MBC3 and MBC5 cartridges are implemented but untested. MBC3 RTC state and GBA saves are not restored.

It does write to mapper registers, in ROM space, because that is the only way the hardware allows a read:

X dump ROM bank registers, which is how a Game Boy cartridge is banked and the only way to read past bank 0 Y dump save the same, plus 0x0A and 0x00 to 0x0000, which open and close the cartridge’s save RAM gate. Closed again on every exit

Ordinary ROM and save dumping does not write save data to the cartridge.

Hold Select for three seconds to open restore, release, then tap A for preflight checks and a recovery backup. After checks pass, release and hold A for three seconds to authorize the write. Wait for RESTORE VERIFIED and TWO READBACK CHECKS PASSED. Keep the PRE*.sav recovery files.

Input preparation and limits: https://github.com/kroy-the-rabbit/openfpga-carttools/blob/main/docs/SAVE-RESTORE.md