JPac to Jamma From Mac

[cobrakai22]

Ive been searching online for some answers and have only found a few.

I recently got a new astro city cab with jamma connection.

A few days ago i ordered ultimar's Jpac and I am waiting to receive it still.  In the mean time I have been looking at how/if I can hook it up to my mac. I love my current setup on mame osx and its so simple I would rather not have to do bootcamp etc.

Here is one of my findings on mac on a arcade monitor, if anyone could take a look and see if this makes sense:

http://www.priglmeier.com/arcade_projects/mac2jamma.html

The problem it seems lies in 15khz, from what I am reading that seems what any computer needs is something to force 15khz (soft 15khz or arcadevga). My questions on that are:

What exactly does 15khz mean within the context of coming from my mac thru vga to the Jpac?

If im in a resolution that is within a 15khz resolution, does that mean im outputting 15khz or ?

Say if im in mame and connected to the jpac, if it switches to its native resoloution why wouldnt it work?
Or is this just telling me what the original resolution is? (ex. of what my game info says within my mame -

Any help would be greatly appreciated!

[CheffoJeffo]

First question that you need to answer is what is the monitor in that Astro City ?

JAMMA specifies connections, not the frequency nor resolution.

You may have a VGA monitor in there, in which case you don't need to worry about driving it at 15Khz.

[cobrakai22]

Monitor: 29 in 15/24 kHz (Nanao MS9-29A)

[DrumAnBass]

You could try SwitchResX but I doubt it will enable you to output a 15khz signal... Here's the link:

http://www.madrau.com/download/latest/latest.html