Book8088 is a new made IBM xt clone. RTD2660 is the LCD controller come with Book8088:
"With it, you can make a 4:3 monitor that can accept both CGA and VGA inputs, which is quite meaningful. However, CGA directly inputs digital signals, which only have 8 colors because it lacks the I brightness signal. To perfectly display 16 colors, you need to build an RGBI to RGB analog circuit. The principle of this circuit is also relatively simple, as the CGA card in BOOK8088 already includes a digital-to-analog RGBI conversion. Additionally, it has implemented brown color correction."
it's opensourced here for book8088 users to fix the align bug and make use of it.