NAOMI on 15khz question

tl;dr: Does the naomi output csync when in 15khz mode or not, and if so, on what pin?

extra bullshit: Some VGA pinouts say pin 13 is Hsync or Csync, some say pin 13 is just Hsync with Vsync on 14. I usually run my naomi on a standard VGA monitor in 31khz mode, but I have a PVM showing up tomorrow (assuming the dipshits at fedex haven't broken it in transit) and I wouldn't mind using the NAOMI to test it. I already have a mini db15 -> RCA breakout box made for use with my PS2 for progressive scan games, but since the PS2 is SoG in progressive scan mode, I don't have a jack for sync wired into that. However, I have plenty of room in the box and an extra free RCA to wire to.

Worst case I could run my NAOMI through my capcom IO and use the jamma wiring for video, but it would be a lot easier for me to just grab video straight from the NAOMI assuming it outputs composite sync in 15khz mode. The capcom I/O doesn't combine h and v sync does it? I'd find that surprising.

The Capcom IO has a switch on it to switch between H+V sync and C sync. I haven't fully investigated what this means, but I do know that my tri-sync monitor goes whacky when I put it on C sync mode. The H+V sync mode also works identically in both 15khz and 31khz (low and hi-rez) settings with my monitor although the alignment differs.

I've tried some other stuff but it's been too long for me to remember it all. Hopefully someone else will pipe in about it.

Thanks, useful info; I forgot about that switch. From what you're telling me I'd infer that the capcom I/O does actually serve as a sync converter then, combining the H and V sync signals. Can anyone confirm that?

Alright, so this is odd.

I wanted to make sure I could get good signal from a JAMMA board to my PVM before I go buying a CPS2. So, I flipped my NAOMI to 15khz, and sent video through a Capcom I/O to my PVM. R, G, B, and Sync, each with a 220 ohm resistor, then straight to the BNC jacks on the PVM.

With csync selected in the I/O, the screen slowly rolls. If I switch the capcom I/O to "H/V sync", the PVM is happy and the picture is perfect.

Am I misunderstanding the purpose of the composite sync / H/V sync switch? It seems that csync would be the logical option for a 15hkz display with RGB/Sync in.