I sourced a 60hz Megadrive (262p) and got it working in x3 mode on the Panasonic FZ802 with the following settings:
H sample rate 1221
H synclen 88
H back porch 130
H active 960
V synlen 3
V back porch 15
V active 240
Hopefully useful to someone. Most of those were left as default or tweaked slightly to get a better picture, changing the H sample rate to some random number was the key to getting a picture at all.
The benefit to this is that I can play with game mode on because the OSSC sorts out the ratio 🙂
I’ll report back if I get 313p working, but I doubt it.