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.
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, Gold fingers (on the edge connector) with a 45 degree bevel to give the maximum life for insertion/removal of the cartridge.
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.