Adapting for use with Retrocomputing...?

[robertjmcintyre]

I came across this project when looking for a solution to supply-chain problems for LCD controller for retrocomputing projects. I'm looking to install an LCD panel in a Commodore SX-64 along the lines of this project:

https://www.allzu.net/en/tlpp/SX_64_TFT_Display_Mod.html

Unfortunately the display board that everyone uses for that mod isn't available any more. I've picked up another board/panel combo:

Board: KYV-N2 V1 (based on the MST703-LF)
Panel: AT056TN52 V.3

The combo works great, except the firmware doesn't support S-VIDEO, which the C64 can use and is much better than CVBS which the display does support out of the box.

I traced the PCB enough to see that the CVBS3/SC1 and CVBS4/SY1 lines are connected to the output connector, so (hopefully) it's "just a firmware change".

There's a significant lack of information on programming these chips, and yours is the only code I can find. I'm wondering:

1. Did you create this from scratch, or is it derived from some other example code/documentation?
2. Did you ever make any progress with migrating it to SDCC, rather than Keil?
3. Would you be open to answering some more technical questions along the way? :)

Thanks!