I finally caved and bought a 360.  Couldn't be without my PacMan CE, right?  Geometry Wars 2:RE as well...  But the composite video cable it came with SUCKED, as you'd expect, so I needed an RGB cable.

I bought a Power Wave component cable.  It's big and heavy, but if you give it more than a cursory glance it's pretty cheap.  No doubt made in china by little girls who wouldn't know an Xbox if it fell on them from their manager's mansion in the clouds. 

Anyway.

I bought it 'cause it had all the teeth in it.  Despite what Ben Heck says, the standard Xbox AV cable no longer has all the connectors, so it wasn't any good to me.  I took the Power Wave cable apart with a flat screwdriver - it's glued together but comes apart easily enough.  Inside it was really easy to re-use.  Remove the protective tape and all the pins are ready for re-use.

I used a SNES RGB cable 'cause I have lots of them lying around.  The SNES end was cut off, and re-used basically without modification.  RGB, Sync, Left & Right Audio, Ground and +5v were easily tapped from the Xbox connector.  I left the existing digital audio output without modification.

The RGB end of the cable had a tiny PCB with 3 capacitors inside, which I removed.  I had to re-connect the RGB in/out wires after this, of course, but that took no time.  +5v from the Xbox is passed directly to pin 11, and to pin 16 through the resistor I removed from the PCB.

As a bonus, the SNES-end stress-relief bit fit perfectly into the Power Wave connector, so it looks totally pro!  =D

There was a HD/SD switch in the Xbox connector which I basically ignored: it wasn't useful for this mod, sadly.  I might rig up a VGA/RGB switch to this later, but for now...  It's RGB only!  =)

Anyway, pics:

Not sure what your point is, RGB32E: What does non-interlaced video (240p) have to do with it?

My TV is not HD capable, so 15kHz RGB is the best I can get from it.  It has component video, but it sucks, with colour bleed, shadows and a red offset that drives me crazy.  It doesn't matter how great VGA and/or HDMI is if my TV's low-res, does it?  =)

And holy shit does it look good.  It looks even better on my 14" RGB monitor.  =D

Lawrence:

I am unfamiliar w/ the video settings menus for the 360.  What mode do you put it in to use an RGB cable like you used?  Or does it just automatically go into that mode when the jumpers are set appropriately?

I have a friend who wants me to make him a cable like this for his PVM but I was a little unclear as to how to set it up!
-ud

That's one of the docs I used to make my cable.  I wanted to know if setting the jumpers is all I needed to do or if I also needed to change settings in the system menus.  I didn't find such confirmation in that document.  Thanks anyways, though.

Yes, if this were for me, VGA would be used, but this is by request for somebody I know.
-ud

Has anybody successfully done one of these cables for a non-SCART application, i.e. some other RGB monitor like PVM or 1080s or somethin'?  I'm having a bear of a time.  My cable is all soldered up, I've checked and tripple checked and still I get a very green tint on my picture.  Right now, Pins 17(Switching Voltage) and 19 (Blanking Signal) are just hanging in the breeze.  These signal are not required for for anything other than SCART TV control, right?  This is thoroughly frustrating.  I'm running a 1080s right now, by the way.
-ud

That's what I was thinking, because I'd seen the same thing on the PS2 when I forgot to change to RGB mode.
That's the bugger.  I can't find anything wrong.  Every schematic/guide I've seen says to short 22-24 and 26-28 (essentially Component and Composite mode at the same time).  That's what I've done and it don't work.  I even tossed one cable aside and tried a totally different cable and got the same results.

Does the XBOX360 cable rely on the TV to do a color space conversion (i.e. convert the 360's component video to RGB)? 

-ud

It can be used, just that the drain/shield conductor for the composite sync coax is what is used to carry red video (due to using only 3 mini-coax cables instead of 4 to carry RGBS).  Though if you remove the scart connector to terminate with a different connector, you'll notice noise on the red channel (due to how red video is wired).  So, you really have to break open the 360 connector hood on this cable and run new mini coax cables to get the best PQ (one for each RGBS, and audio).

Could you describe the specific problem (I didn't catch that)?

What monitor are you trying to connect your 360 to?

What specific cable are you using?

Could you post any relevant pictures of the cable, monitor, ect?

The pinout for the PC2Jamma spec is the standard HDDB15 connector, often times more than one ground connection is needed (pin 5 and 6/7/8).

OK I am wanting to hook my 360 up to my 15 khz Arcade cabinet.  Can you USA 360 output 15 khz RGB?