LCD Controller Overview
The Pokemon Mini LCD is a serial display with it's own on-board framebuffer, and display settings. These are all abstracted by the PRC, which handles display copies ($1000 ~ $12FF) and other various functions. No commercial roms directly access the display, relying on the PRC and BIOS to perform the various communications. This allows for the PM to have hardware changes without having to rely on the same display controller.
The display is driven by two data ports, $20FE and $20FF. Both ports are read\write, the only difference between them is one sets the CTRL line when accessing the data port on the LCD. The port is 8-bits wide, and has a small set of standard commands
LCD Controller Commands
|$1x||Set Row (?)||x = Row|
|$81||Set Contrast||Constrast Level ($00-$3F)|
|$Bx #nn #nn #nn||Set Column (?)||x = Column, followed by GDDRAM data|