The blue/pink carts will fit the following shells – DMG, GBC, Crystal (Japan/USA) and Kirby check the pictures. It can also fit the Boxy Pixel shell but requires the capacitor next to the flash chip to be removed (and placed above it).
The 4MB blue cart (v1.2 PCB or below) will only fit in original DMG style or GBC style cart shells (GBC style requires 2 small cuts), won’t fit in Japan Crystal shells.
This cart works on every Gameboy system – GB, MGB, GBC, GBA, GBA SP and the Game Boy Player. It also works on the N64 transfer pack for Pokemon Stadium 1 & 2 (as per a user report).
4MB Option Capabilities
v1.2 PCB allows for Rumble (supply your own motor, requires game patching to use, check example) and 2x 2MB ROM Mode which allows you to switch between 2 ROMs such as Gold/Silver to share the same save file (shell cutting/trimming is required to fit the switch, the shell won’t close unless you trim the top part of the shell but be sure not to cut the little notch).
How to use the rumble motor
You need to write the byte 0x20 to 0x4000-0x5FFF. Usually games write 0x08 but that would conflict with the RTC so you need to patch games to use 0x20 instead. For Pokemon Pinball we have an example patch to apply but it doesn’t appear to activate the rumble strong enough – you could lower the resistor if need be.
How to use 2x 2MB ROM Mode
Check the picture as you need to bridge jumper pads with solder and un-bridge another jumper pad. You’ll also need a special program to flash both ROMs to the cart: 2x 2MB ROM Mode Flasher v1.1.
ROM: 4MB or 2MB Flash depending on the option you select
FRAM: 32KB (Data retention of 20-50 years)
MBC: MBC3 original chip
The power consumption of MBC3 when powered from the battery appears to depend on the chip markings which is either around 2.3uA or 5uA so a CR2025 should last at least 2-3 years and a CR2032 should last at least 4-5 years. We don’t recommend using a CR2032 battery as the holder is only designed for a CR2025 battery. Only the RTC is powered by the battery so the save is retained if the battery runs dry.
The PCB finish is ENIG.