s-video scart 15khz confusion

[Johnny5]

So I'm gonna build my first cab. I have a 27" CRT TV with a scart and an s-video input that I plan to use. I don't want to set it up as a dedicated arcade monitor cos I wanna run other emulators other than MAME like n64 or Genesis and they'll look rubbish at 15khz right? So I don't want it to output at 15khz all the time, so what's the best way to hook it up to the PC? VGA to scart will make it run at 15khz all the time right? so shall i go with s-video?
Is there a graphics card that can automatically adjust between 15khz and 35khz? I haven't purchased one yet so I'm open to suggestions.
Thanks in advance

[Ummon]

You really need to understand how various monitors and consoles work, but a hint is in the following question: what definition is your TV?

[richms]

n64 and snes are nativity 15kHz - so they will be perfect off a 480i mode on the video card at 15kHz.

Using the svideo out will just mean that you are running the VGA thru the scaler and reducing the quality to pal or ntsc, with the processing the chip does. Yeah, the desktop will look a hell of a lot less flickery, but it will not be the authentic signal like you would get out of the RGB out of one of those consoles, whereas the VGA to scart will be able to deliver that

[ahofle]

n64 or Genesis and they'll look rubbish at 15khz right?
So I don't want it to output at 15khz all the time, so what's the best way to hook it up to the PC?
VGA to scart will make it run at 15khz all the time right?
so shall i go with s-video?

In order:
no,
SCART,
yes,
no

 

[Johnny5]

Thanks for the links and the info so far guys. I understand it slightly better now.
I didn't know about advanceMAME auto adjusting the resolutions for games. That's cool.
What I'm still a little confused about is how to find out how many lines my TV runs at. All I can find out is that it's 50Hz. 
If for instance I did come across a game that ran at 25khz, would it work at a fixed 15.7khz resolution without damaging anything?

I only own a Mac and macMAME is no where near as advanced as these PC frontends. So it's quite hard for me to understand the setup procedure until I purchase all this equipment and try it out. That's why I wanna make sure I buy the correct stuff first time round.
For a first time project I'm not super bothered about getting it to look perfect, I just want to make sure it all works.
I was thinking of getting the Trident Blade 3D card. Is that a good option?

[ahofle]

Standard definition CRT TVs have somewhere around 300 max lines of resolution.  Your TV should be able to run just about every horizontal CGA (15khz) game, pretty much any console game prior to the high def ones, and most vertical games (256 lines max and under in my experience).  Everything else (including 25khz games) you can run with 'interlaced' 640x480.  Read this for a description of interlacing: http://en.wikipedia.org/wiki/Interlace#Description
You may be better off just getting an ArcadeVGA which will automatically limit the available resolutions that your TV/arcade monitor supports (a bunch of 15khz resolutions including interlaced 640x480).  Then you won't have to worry about damaging anything.