I didn’t want to ask until I tested both, but I bought a virtual tap a while ago used from someone, which unfortunately came without the sticker indicating which type of board it was, so I tested soldering it up to both RGB and VGA respectively, and both show up as “no sync,” or basically no input, on my ossc, and no input on my monitor either connected through VGA. I don’t know if it went bad or not somehow from the previous owner, or how to check that, but from wiring it up it’s getting voltages at each point while connected and unplugged from the upscaler, so there’s continuity to rule out. If there’s a way to tell which it is from the Hz or something, that would at least get me looking in the right direction. Thank you for any help anyone can provide, any help is absolutely invaluable.
Both run at 60 Hz. However, on the RGB version, composite sync is provided on the vertical sync line, and the horizontal sync line is unused. On the VGA version, both horizontal and vertical sync lines provide sync. If you can hook up the horizontal sync line to a scope, you should be able to find out quickly which version you have.