I forgot to mention. After using your trick with V.active at 256 and reducing the V.backporch to 6, the graphics coming out of the OSSC were still a bit ‘off’. Sections of the screen were fuzzy/out of focus and the in-game text (score and timers in Sonic 2) were wrong. I’d make some photos, but I’m lazy and the TV is currently being used for Netflix 🙂
Edit: this next section is stated more clearly in a previous post.
To fix the graphics, I used the following process:
– increase H.samplerate until all in-game text is output sharply and fuzzy bits are eliminated (this restores the correct scale on the horizontal axis). It’s hard to describe, but the process was basically just incrementing by +1 until stuff all of a sudden just looks right. Using a screen with text on it is good because it’s easier to tell when a letter is messed up, compared to a game character or piece of scenery
– adjust H.backporch to centre image
– reduce V.active from 256 to 240 (this gives the correct scale on the vertical axis)
– correct AR is now restored and it now looks goddamn amazing
The only issue is with my display, the image is pushed down quite a bit and ~7-10 lines of graphics at the bottom of the image are pushed below the bottom edge of the screen. It’s a small price for an amazingly crisp and vibrant image.
Thanks again for the tip. Hopefully these extra bits will help others get the most out of their OSSC/display combo.