The Pokémon Mini was first released in 2001. It’s centered around the Pokémon franchise. Apparently it was no commercial success because it was canceled soon after its release.
It’s probably the system with the smallest interchangeable game cartridges. It consists mostly of custom Nintendo parts, few off-the shelf parts were used (most notably the EEPROM).
96×64 1bpp LCD display
More shades can be displayed by taking advantage of the LCDs slowness.
Custom Nintendo 8 Bit CPU with 16 Bit instructions running at 4 MHz, coined “MINX” by Team Pokeme
4096 Bytes, there exists just one known BIOS version
4096 Bytes shared with the Video unit (if it’s activated)
Very small cartridges with up to 8 MBit of memory. All known commercial ROMs are 4 MBit.
Single channel PWM sound (square wave) with three volume levels.
8192 Bytes external I²C EEPROM
One of the few off the shelf parts used in the PM, the AT34C02 is a close match.
Shock detector (no accelerometer!)
70g with Game Pak and battery
74mm x 58mm x 23mm