[Keith]

Graham,

Thanks for your latest post - very interesting.

When I reboot the PC, it's still in dual screen mode but I don't get the 664x377 line for screen 2 on the display resolution slider - it still shows 640x480 (next one up is 800x600). I know the scope is looking at display 2 as when I click "Identify" on the context menu, I can see the change on on the video. The real problem seems to be that the line time won't go above about 60uS.

I've downloaded the Winmodelines folder from your Google drive - thanks for that. I shall try the earlier version of the editor shortly. I might also try reloading the NVIDIA driver. This time I'll uninstall the old one first which I didn't do last time.

Great YouTube video - I can see exactly what's supposed to happen. Looking forward to trying Vid Blaster - looks like great fun!

Peter,
Yes I did change to 50.0Hz but it still comes back as shown.