Hi Zebidee, thank you for the reply!
I don't think this is an overscan issue - the last scanline is nowhere near the bottom of the screen. I've adjusted the vertical height way down so we can be sure there's no cropping on the top and bottom, and I'm going through the video modes in arcade OSD here:
https://drive.google.com/file/d/19tWdLeG8p_jrBBt_NsxS0sWWoReADpQX/view?usp=sharingWe can see that in some modes, for instance, 320x224@60 (15.66khz), the full image is drawn, you can see the bottom white border. Whereas the very close 320x248@59.97 (16.13khz) doesn't reach the bottom white border, and in fact, you can see that it in fact stops mid-scanline here...
My first thought is that anything over 15.6kHz can't be displayed by this Sony KV-XXX, but then 336x224@60 (15.66kHz) works fine but one at a little lower frequency 384x240@59.98 (15.65kHz) does not work.
Is there something here I can adjust in the range when generating modes, or the service menu, that could assist with these couple modes that appear not to be drawing the whole image? Or is maybe something else going on here - failure to sync is one thing, it obviously can display these modes, but cutting off scanlines is
something else...
My preset is
monitor "roger", "Sony KV-20FS100", "4:3"
crt_range0 15625-16750, 56.0-65.00, 2.000, 4.700, 8.000, 0.064, 0.192, 1.024, 0, 0, 170, 262, 448, 526
I did just replace my modelines with the
ntsc preset, rebooted, and it doesn't seem to have done anything.
Is this what foldover looks like? I thought foldover looked like the image "bouncing" off the top or the bottom and drawing again over top of itself, like it had been folded at the edge, but I could have a misconception.