Reply To: Atari ST SYNC loss on demos

[BuckoA51]

Could be the ST demos are using some trickery that your display doesn’t like when line doubled or processed. Sync losses are to be expected on scenes where demos switch to other screen modes, for instance.

I would try increasing H-PLL Pre-Coast H-PLL Post-Coast coast to 4 or 5 see if that makes a difference.