Sanyo 31C426 RGB input pinout

[colorfixer]

All might not be lost. See if you can get a schematic for this beast. You may be able to simply remove the gates that are in the video stream, or apply your RGB video to the output of this daughterboard directly. This monitor looks a lot like the original 20EZV arcade monitors which had cabinets rather than metal open-frame chassis.

Originally Posted by ituba

Thanks Titan1a, dr.ido, Zenith26kc20, and Findm-Keepm for your help.

I could not find any info on old Proton TVs, but I think Findm-Keepm has the correct answer and it is a digital RGB input. I pulled the rear cover and took pictures of the circuit board the RGB input is connected to. My understanding of electronics is limited, but it seems to me that the RGB input connects to the two ICs on the front of the board, and these appear to be digital gates.

So, Titan1a, this would work well with your Commodore 128.