New 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 Flash (MBM29F033C)
FRAM: 32KB (Data retention of 20-50 years)
MBC: MBC3 original chip
The power consumption of MBC3 when powered from the battery appears to be around 2.3uA so a CR2025 should last 5-7 years and a CR2032 should last around 7-10 years.
The PCB finish is ENIG.
If you will be installing this flash cart in an original shell, it is very difficult due to the CR2032 battery holder but it is possible, some users prefer using a CR2025 battery holder instead.