I have an RGB modded AV Famicom that has a SCART RGB cable. How can I use this with a PC monitor?
PC monitor would be expecting a separated horizontal and vertical sync, RGB Famicom outputs a combined sync signal.
So you would need to separate the sync channels and adapt the scart socket to VGA.
I believe a device such as the Arcade Forge Sync Strike may work.
try this
http://www.geocities.ws/podernixie/htpc/cables-en.html
I plan to make it my self for SEGA SMS and MD :)
I made that same cable for my raspberry pi 3.
Famicom runs in 240p so even with the correct cable a pc monitor might not support it.