Great, thank you marqs, that explains it. I did see the subcarrier discussion earlier but it went over my head at the time.marqs wrote:For 1) you need to disconnect BH7236AF video encoder pin 6 and connect that to snes_dejitter CPLD pin 11 which provides clean subcarrier. I think there was some discussion about this a few pages back. The latest firmware from nes-fix branch must also be installed on the board.
Full disclosure, I have had trouble with 256x240 optim mode on the NES even before this. Most recently I couldn't find sampling settings that gave me a completely clean picture, but at least I was able to see the full width of the image. I suspected my dejitter rewiring was responsible for this setback, but perhaps it's unrelated. Maybe my NES and display are just not destined to be compatible with 256x240.marqs wrote:2) sounds strange, are you sure your display has showed it correctly in that mode earlier? You might also want to take a look into NESRGB dejitter modification which might be easier in the end if you want to preserve cvbs & s-video.
I was actually contemplating upgrading to the NESRGB 2.0 with built-in dejitter. I'll have to weigh that versus getting into the dejitter board firmware updating. I recall the earlier discussions about how complex that can be. Anyway, thanks again for your help.