Xbox RGB Help

[RARusk]

Recently I purchased an Xbox and began playing the GTA Double Pack so I could make revisions to my text based guides that I have posted on several sites. Natuarlly, I want to use RGB and I managed to build a Xbox cable (15Khz RGB) for use with my RGB box (which contains a EL1993 sync separator chip and a CXA1145 chip (for amplification)) using the pinout information from GamesX. It works quite good but there is a minor problem with the picture.

I have noticed a slight wavy interference that is most noticable with a gray or green background. It may be coming from the Composite Sync signal that is being run through the 1883 (the interference is actually worse on the EL4583 sync separator chip). When I tried to use the sync straight from the Xbox, I found that it doesn't work on either my NEC MultiSync 3D or Commodore 1084 monitors. Is there any way to condition the Composite Sync to make it work on my monitors (or at least remove the wavy interference)?

Of course I would rather prefer to use the native VGA signal within the Xbox but Microsoft would rather deny me that pleasure. Does anyone know of a motherboard hack (no firmware uploads) to restore full VGA function to the Xbox?

Finally, is there any way to install a lithium based disc battery within the Xbox so I don't have to reset the damn clock everytime I turn the thing on? I have my Xbox plugged into a power strip that I turn off each night and it would be nice to have my Xbox keep the time and date after being switched off.

[Endymion]

I'd just get ahold of an XBox SCART, but then I plan to try to go "all SCART" for my RGB stuffs by way of a switchbox I imported off ebay--one mod to do and that's it. The SCART cables I've used have yet to give me a problem.

The going method of making a VGA signal from the XBox's native output was a component conversion, the first implementation was a modification of the HDTV/component adapter box. I could have sworn there was a schematic or a writeup on this when I first saw it nearly two years ago, but googling just now (xbox vga adapter) only turned up items to buy, like the X2VGA.

[benzaldehyde]

Hiya,

It would seem the "shimmering" you are seeing is a symptom of just about any new game system. I'm not too sure why, though I want to think it could be the fan in the new consoles. Of course, hi-res screens on the PSX and Saturn give the same effect, so I really don't know. No amount of shielding seems to alleviate the problem (Tin-Foil Saturn = Negative, sir!).

Curse Microsoft! There is no motherboard mod that can restore VGA capability. You will need a modchip and new BIOS to do so. Even then, you need to patch just about every game to get it to work right. Or... you could get an inexpensive transcoder from Hong Kong (like I did, twice ). They work great; not perfect, but great.

Curse Microsoft again! The battery on that thing sucks. I just concede to leave my power on all the time. No problems yet, though.

If I could ask you, as a Multisync 3D owner, have you ever had any trouble with yours? I use one, too, but I have a hell of a time getting it to sync properly. Furthermore, the only systems that function with it are my SNES, Genesis, PS/PS2, and Gamecube. No XBox! No Saturn! No Turbo Grafx! No Jaguar! (No wait, that's not so bad...) Does it seem to work better with separate sync signals (with the EL1883)? Where did you find your ICs? Thanks a bunch!

Edit: Mwha! Endymion posted the same info right fast! I've scoured for those schematics, but it seems to be a bit of a trade secret. It would probably end up being more expensive to build one yourself, though.

[Endymion]

I think Jeremy had a review here on the X2VGA late last year? Is it nicer than the modified Xbox component adapter?

Edit--sho' nuff, here tis, looks like a pretty good box, if you are interested in an Xbox only adapter, costs a lot less than the other transcoders. Do they really throw in that switchbox for free?

<hugs his Performance Dreamcast VGA box with passthrough>  B)  

[RARusk]

In response to benzaldehyde in regards to the shimmering problem, it may also be the hard drive causing the problem. I also found out when first using the Xbox in RGB is that I had to adjust the horizontal size because it was very wide. This was unusual because every other console I have used with the sync chips had the opposite effect.

You mean that there is actually a battery on the Xbox motherboard? Looks like DVD-ROM drives wasn't the only thing Microsoft cheaped out on when building the Xbox.

I don't have any problems with my MultiSync other than the picture takes a bit longer to brighten up (may be due to age). The thing prefers seperate sync rather than composite-sync-on-green. For the CXA1145 RGB chips, I go to thrift stores and buy Sega Genesis units and hack them out. Much cheaper than going online. I can buy two Genesis units for the price I have to pay for one chip. Plus I can get spare parts from the units too. As for the EL1883 sync separator chip, I asked Intersil for a sample pack and got two units. I don't know of any place off the top of my head that currently sells them right now. You can probably use the EL4583 chip as well but if you plan to play movies in RGB off the PS2 you will need the EL1883 since it is the only chip that can ignore the MacroVision copy protection (MacroVision can mess up the sync when playing movies on any other sync chip like the EL4583. You can't tweak it to compensate.)

I have seen the X2VGA box. I like it but I would rather try to get the native signal out first. I am sure that there is a motherboard hack for VGA just waiting to be discovered. I know that there is no hack at this point but I want to try to tweak Microsoft's nose a little bit if I can and get what I want.

Console hacking is like sex. For best results you gotta know where to poke.....

[Endymion]

Well I wasn't trying to discourage the effort, but I think you are underestimating the essence of a BIOS (firmware) that creates the signal you want.

Put it another way, I think that if you reverse-engineer your question a little, you could probably get the answer you are looking for. Example: can the nforce PC board create VGA graphics without its BIOS? If so, then you have great hope of simple physical tweaks creating a VGA native signal. Otherwise, you will have to provide the BIOS that does this, which is what the mod is all about...

[RARusk]

Did some additional research at some of the various Xbox hacking sites and found that getting native VGA is a lot harder than I hoped. Especially since I have one of the newer models (9/03) with the Focus chip. I also have a feeling that the new Focus chip is part of what is causing the slight shimmering problem in 15Khz RGB. I have also found that by adjusing the contrast and brightness enough I can get most of the shimmering problem to go away however I would like to try to completely solve this problem for good.

I don't understand why MicroSoft wouldn't allow us to use VGA although I think that they were just flexing their evil ways just to piss us off. I may have to go the transcoder route and see if I can get a Progressive Scan Dashboard and DVD hack to get where I want to go. I've seen the two main transcoders, X2VGA and VD-Z3, and I think that the VD-Z3 appears to be the better one of the two. I am also going to do some research and see if there are any other transcoders out there and compare prices and features.

And I've been too busy looking for VGA hacks to look for a battery hack.....

Oh, one more thing. Nu Horizons Electronics (nunext.nuhorizons.com) is currently selling the EL1883 sync chip if anybody here is interested in acquiring some. Just leave me a few OK?......

[benzaldehyde]

Hiya,

I've got both of yonder transcoders. Both produce nearly identical pictures, and both can handle all higher resolutions. The X2VGA is better for exclusive XBox use, as it bypasses another connection by plugging directly into the XBox. The VD-Z3 can accept any component-progressive signal, so it is more flexible. The X2VGA has a digital audio port installed; you'll need an HDAV pack to get such audio from the VD. Here are few reviews from the forum.

VD-Z3 Review

X2VGA Review

Also, I heard something about them being compatible with the Pixel8 bios. Not sure how, though...