gb pocket lcd inverter
this is a circuit which will invert the LCD signal in a Game Boy Pocket (MGB). in combination with an inverted polarization film in a backlight, this is commonly referred to as a 'biversion' mod (meaning, it has two inversions; one via the circuitry and the other via polarization film).
this board fits over the 100nF buffering capacitor next to the GBP's CPU. there are solder pads on the circuit board to solder to this capacitor, which provides access to GND and power. from here, you use the 4 solder tabs on the edge of the circuit to connect to the LCD and the CPU pins. the signal then passes through this circuitry and provides the inverted effect.
please see photos for a better explanation of this connection approach.