Great Pattern. This was very interesting. With TheatTek 2.1.1/NVidia 7800 I can see on pixel border. I am assuming that is zero overscan.
With MyHD 1080i, I did some adjusting. I can get to zero overscan horizontally, but the vertical never delivers the border, but it is close. Watching PBS-HD and some 4x3 content you can really see that some stations have not figured how to crop the broadcasts.
Oppo UPD-203 | Sonica DAC | BDP-105D | HA-1 | PM-1 | Emotiva XMC-1 |ATI Signature AT6002 x 2 + AT6006 | Revel Salon2s, Voice2, Studio2s | Velodyne HGS-15 | LG B6 | Lumagen 2020