tama102 --
Many, many thanks for this thread!
I started out with an ATI card in my MythTV box, and it picked up the resolution for my SP4805 with no issues at all... Very quickly, I upgraded (felt like a downgrade...) to an NVidia card so I could use XvMC... I spent about 3-4 days trying to get 848x480 working again. I got so frusterated, I took a break... it was only supposed to be for a few days, and it turned into 6 weeks because of real life issues.
Anyways, your instructions worked perfect. For the sake of completeness, here is my working monitor section:
Code:
Section "Monitor"
Identifier "Monitor0"
Option "VendorName" "Infocus SP4805"
Option "ModelName" "Generic Autodetecting Monitor"
Option "NoDDC" "1"
Option "IgnoreEDID" "true"
Option "UseEdidFreqs" "false"
Option "DPMS" "false"
HorizSync 25 - 80.0
VertRefresh 50.0 - 85.0
Modeline "848x480" 37.293 848 936 984 1104 480 508 509 563 +hsync +vsync
EndSection
Thank you for your persistance!