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Previous MROM releases are for reference only - please use the latest for best experience.

open issues - 05/02/2026 (all versions)

• ROM and RAM data saved to SD card corrupted by screenshot (cached content corruption)

ROM, RAM (savegame), and screenshots share the same staging area in memory before being written to a file. After the initial menu selection, if a screenshot is triggered, wait for it to complete. Then, exit the selection with B and reenter with A. The cached data from the cartridge will be reloaded.

All the issues listed under a release only apply to the specified version.

MROM-ED3A_B951.zip - 2026 Alix

• experimental build w/ RTC support
• MBC3 up to 32KiB writeback
• MBC5 up to 32KiB writeback

Developed and tested with Pocket firmware version 2.5 (APF @ 1.2)

MROM-ED3A_210B.zip - 2026 sweet Valentine

• ROM only (32KiB)
• MBC1 w/ up to 512KiB ROM, up to 8KiB savegame
• MBC2 full support (incl. savegame) - multiformat (openFPGA + S/W emulation)
• MBC3 up to 32KiB savegame⁽¹⁾, no writeback for savegame > 8KiB, no RTC
• MBC5 up to 32KiB savegame⁽²⁾, no writeback for savegame > 8KiB

Developed and tested with Pocket firmware version 2.5 (APF @ 1.2)

MROM-ED3A_579A.zip - 2026 winter wonderland

• ROM only (32KiB)
• MBC1 w/ up to 512KiB ROM, up to 8KiB savegame
• MBC2 full support (incl. savegame) - multiformat (openFPGA + S/W emulation)
• MBC3 up to 32KiB savegame, no writeback for savegame > 8KiB, no RTC
• MBC5 preliminary support, no ROM size limit, up to 8KiB savegame

Developed and tested with Pocket firmware version 2.5 (APF @ 1.2)

known issues for ED3A/579A - 01/17/2026

• Pokémon Pinball ROM/savegame file path shows random characters (+ present on other GBC games with DMG compatibility)

ROM and savegame will be written with the correct filename (under /DMG) on the SD card. Only the on-screen path confirmation is garbled. Games with $80 @ $0143 are considered DMG games and not CGB by Nintendo.

MROM-ED3A_2012.zip - 2025 Santa preview

• ROM only (32KiB)
• MBC1 w/ up to 256KiB ROM, no savegame support
• MBC2 full support (incl. savegame)

Developed and tested with Pocket firmware version 2.4 / 2.5 (APF @ 1.2)

known issues for ED3A/2012 - 01/10/2026

• Pocket Sync appears to remove the DMG and CGB folder (INSTALL)

(Empty) DMG and CGB folders must be present during install in /Assets/mrom/common.

The Pocket file I/O API is very limited and therefore these folders cannot be created on the fly.

• savegame write to SD may hang (RAM)

It is predominantly impacting systems with a high number of files present on the SD card. Workaround, use a card with just the base files for the Pocket and MROM.

• Pre-existing 0 byte *.SAV files will freeze savegame write to SD (RAM)

Workaround, simply delete the file with a computer.

• openFPGA GBC uses the Saves/mrom/common/<platform> folders for savegames

Use a computer to move save files from Assets/mrom/common/<platform> to Saves/mrom/common/<platform>.

• openFPGA MBC2 savegames format is different from software emulators

This version only supports S/W emulator compatible MBC2 savegames. Not compatible with budude2's openfpga-GBC core.

05/2026