SGB Schematic

Super Gameboy Schematic

This schematic includes:

SGB CPU (With pinout)
LH52A64N, 8192 byte work RAM (With pinout)
LH52A64N, 8192 byte video RAM (With pinout)
TC53200 and F411A (Probably the ROM chip for the snes software and a lockout chip, respectively)
ICD2-R the bridge between the SGB CPU and the SNES. Handles video and key presses. More info wanted.

The SuperGB main chip has the necessary pins for serial communication. Thus it is possible to add a link port to a Super Gameboy. Super Gameboy 2 was shipped with a link port.
It is not known whether the Vin pin of the SGB CPU works as intended.
What does the PX pin do? (Pin 53 of the CPU)