Checkmate Display
Random Notes while testing my brand new old skool Checkmate Display (a 19" 1280x1024 IPS display with several 'old' inputs)
- AppleTV 4K: Set to 720p SDR because 1280x1024 gave a stretched image. Apparently the AppleTV has several resolutions but always expects 16:9 display. Alternatively, leave scaling to the display by setting it to 1280x1024@60 and then you can set 16:9 on the monitor to squeeze the image back to a good aspect ratio.
Sound not working, need to test/read more.