Topic: So Wait, Will This Work? (Read 164 times)

AliasCT · « **on:** August 20, 2007, 06:48:00 AM »

So I found an old thread that linked to this old thread, and I got curious. Having a couple chips that could (I'm guessing) fit in your xbox that would convert the component signals to VGA without a VGA bios would be brilliant, yeah?

So I'm really curious as to why this never progressed; by the accounts of those who tried it, it worked, right? I don't think I would go much beyond 480p on my monitor, I just want to *get to* high def lol.

The original schematic was complicated, it was said, and required a lot of components, but this tut posted at the end of the thread looks fairly simple. You only have to follow the schematic and then your done? It looks like you only need one extra chip from the current vga mod tut made by jared (I love that tut, its brilliant too, I just want a VGA socket that I don't need a VGA bios for), not sure *exactly* what it does, but does it really make that big of a difference?

Is this project still viable?

spillage · « **Reply #1 on:** August 21, 2007, 01:42:00 PM »

I have to be honest, I achieve 5 wire RGB aka VGA using the tried and tested X2VGA. It works ALL the time and offers what you want. They're cheap enough nowadays. If you have to build something, try the circuit. It is a component transcoder, that is to say it take component from the xbox, strips of the sync data from green and generates clean H and V sync data using known values from the data on green. I see no reason why it won't work but I have my doubts regarding noise unless you can make a proper PCB with a good ground plane for shielding. MAX chips usually like a good ground plane.

AliasCT · « **Reply #2 on:** August 21, 2007, 11:21:00 PM »

I have absolutely no problems with using the X2VGA, its a brilliant piece of equipment and works well and doesn't cost all that much. I'm planning to do a case transfer mod and I thought it would be fairly cool to just have a VGA out on the back of the case, though, so preferably it would be something that could fit in the case and wouldn't be hard to wire up. Would it be possible to do that with the X2VGA? If there's no *really* good way to wire up the VGA port then I will probably invest in an X2VGA.

spillage · « **Reply #3 on:** August 23, 2007, 04:29:00 AM »

My X2VGA is mounted inside without its case. See IPB Image

In one of the images you can see the X2VGA mounted on the bottom left on the image in the collage. You can see the phono sockets sticking up.

AliasCT · « **Reply #4 on:** August 23, 2007, 07:14:00 AM »

That would be pretty much *exactly* what I was looking for, thanks! Did you just solder the component lines straight to the motherboard?

spillage · « **Reply #5 on:** August 24, 2007, 02:42:00 AM »

No, my case is just deep enough to allow the use of an AVIP plug without the plastic on it. Removing the AVIP plug trouble enough. Soldering a lot of wires to it as I have done before is another time consuming and frankly IMO unneccassary exercise and looks really messy. The use of good screened cable for video directly on the AVIP PCB lands is too much messing about for so little return. Nevertheless I commend anyone who does it and does it well.

yaywoop · « **Reply #6 on:** August 28, 2007, 02:58:00 PM »

I was going to make one of those. i even ordered some samples of the MAX 4383.
then i realized how much it would cost to get all the strange resistors..... and to make a dual layer board
anyway i ended up taking the "easy" way - a VGA BIOS. and the not so easy way of getting sync signals - internally.
it works fine for a lot of games (great for XBMC) and it works on *ANY* screen with a VGA port.
but i am cheap and you probably have money so take that into account

AliasCT · « **Reply #7 on:** August 31, 2007, 11:59:00 PM »

QUOTE

I don't know if you're aware but National make a YPbPr to RGBHV Converter and 2:1 Video Switch on a single chip.
Check out the LMH1251 to see what I'm talking about.

The only down side to it is the form factor it comes in..... 24-Pin TSSOP (7.8mm x 6.4mm)
It also requires a triple video buffer (LMH6739, LMH6734 or LMH6733) to drive a vga monitor. That said, it is a very simple looking solution with high accuracy.

Here's a circuit I found on the lumenlabs website:

The circuit is almost identical to one in the data sheet for driving a VGA cable.
I noticed there were no values for the zener diodes in either of the diagrams so if anyone out there has any idea what they might be, please let us all know.... I might be able to find out in a month or so when I go back to university and ask some people there if no one here can figure it out.

Actually, I did - while wandering around links from the threads I mentioned earlier - stumble on that. It would be perfect; if it wasn't $150.

AliasCT · « **Reply #8 on:** September 01, 2007, 05:26:00 PM »

I guess you're right, I don't know what the other ones do, but this is the line I was looking at.

LMH1251EVAL | YPbPr to RGBHV Converter and 2:1 Video Switch | Full production | N/A |

1+ $151.00

smoke_screen_uk · « **Reply #9 on:** September 02, 2007, 02:06:00 AM »

I take it you're only looking at the manufacturer's page and prices. If you look around I'm sure you'll find a retail company that buys 100s of these things (like farnell in my example) and can then sell them on at a much more reasonable price (somewhere neared to the 100+ price on the manufacturer's site.

Author Topic: So Wait, Will This Work? (Read 164 times)