I did a lot of experiments with DueVGA:
https://github.com/stimmer/DueVGA
A much less capable microcontroller (84MHz Arduino Due) with much less memory (96KB ram).
You may want to lookup stimmer's DueVGA code on Github for how he did.
Allows for 1024x675 monochrome and 320x240 color, only restricted by ram size.
Only 3 resistors are needed for monochrome connector, 11 resistors for color:
http://stimmer.github.io/DueVGA/
https://forum.arduino.cc/index.php?topi ... msg2575055
