This is a multi-post tutorial spaning 3 posts mainly writen my me, but some sections copy and pasted, all/most
sources are included at bottom of last post.
This tutorial will make it so your Xbox will work on computer monitors (or anything with a VGA input).
Please note, with the exception of option c, this project requires you to have an Xbox with a modchip, to see
what option c is, it’s easer to read the whole thing. I wanted to do this to my Xbox and couldn’t find a tutorial
for it, so after about a week of research (after school and all) I had enough info on what to do. I looked
around, and couldn’t find any similar tutorials so I decided to make one . When I have a link I have to refer
to, I will say [link 12] or something, look at the bottom of the post to get the corresponding URL. First off,
you will need the following things.
-An Xbox (only works for 1.0-1.1 versions I think, to see what kind you have go here [link 1] )
-A modchip in your Xbox (except option c)
-Xbox scart cable (usual A/V cable, comes with Xbox, but best to buy a spare for this project)
-A VGA Extension cable, or at least a female VGA connector & some cable.
-LM1881 Video Sync Separator semiconductor IC. (depending on you monitor)
-2x 0.1µF capacitors (depending on you monitor)
-680kO resistor (depending on you monitor)
-A VGA patched firmware [link 6] (you don’t need this if you have a X3 -modchip or are useing option c)
-Wire Cutters and/or knife
-Soldering iron, solder, usual soldering kit
-Insulation tape
-Enough time the read this too goddamn long Tutorial!
Background (skip-able but interesting to know)
First, if you already know this or don’t care (it’s not necessary to know this) just skip this part. The objective
of this is to get VGA output on your Xbox. Your Xbox cannot output true VGA. Well, that last part is not
entirely true, when your done reading this, check out option c. VGA works by having a red, green, and blue
channel and a H sync and V sync. The Xbox supports component video, blue, red, and green but no H or V
sync. But there’s an easy alternative, it’s called SOG or sync on green. What it does, it to combine the sync
information into the green channel. That’s what we’ll be using. Now, to get that does not happen when you
switch your Xbox into component video mode, that’s where you need the mod chip, it will modify your video
encoder and make it include the sync with the green. Methods, pure sync-on-green and sync-splitter, suffer
from the fact that the Xbox does not deliver VESA compliant sync-on-green signals. The VESA standard
requires sync pulses with negative voltage, with the color signal starting at 0 Volt. The Xbox, however, cannot
produce negative sync pulses. Instead it uses a positive voltage offset on the green signal with the sync pulses
going down to 0 Volt. This may result in a slight color shift, depending on how well your monitor is able to
cope with the voltage offset. Usually dark gray colors will appear slightly green.
What option to use?
There a two general ways to solve this problem:
a) Some monitors can read the sync information on the green channel, if yours does; you can use the
easer option. To see if your monitor supports this option go here [link 2]
b) If your monitor does not support SOG, you will need to build a simple circuit that extracts the sync
information from the green signal and split it up into h sync and v sync signals.
c) Using the Xbox's internal sync signals (not a viable solution, only for people that are mad good
soldier’s)
Option A
And here's the VGA connector, again seen from the cable side to the PC side
If you monitor supports "Sync On Green" you're lucky - you just need a plain cable to connect your
AVIP connector with your VGA monitor. No additional electronic components are necessary.
First of all, the picture below shows the pin numbering for the AVIP connector seen from the cable
side to the Xbox side.
_______________________________
/24 22 20 18 16 14 12 10 8 6 4 2\
| 23 21 19 17 15 13 11 9 7 5 3 1 |
-----------------------------------
AVIP Connector
___5_______1____
\ o o o o o /
10 \ o o o o o / 6
\o o o o o /
----------
15 11
VGA Connector
You need to make the following connections:
AVIP Pin 19 to VGA Pin 1 (red)
AVIP Pin 22 to VGA Pin 2 (green)
AVIP Pin 18 to VGA Pin 3 (blue)
AVIP Pin 17 to VGA Pin 6 (red ground)
AVIP Pin 20 to VGA Pin 7 (green ground)
AVIP Pin 16 to VGA Pin 8 (blue ground)
AVIP Pin 9 to AVIP Pin 10 (Mode select, Bit 0)
AVIP Pin 13 to AVIP Pin 14 (Mode select, Bit 2)
The connections of AVIP Pin 9 and 13 are necessary to select the cable ID. The above connections
will result in a cable ID of "2" (make sure AVIP Pin 11 is unconnected). This way the Xbox will be
able to detect the cable and set the correct modes.
For audio signals, (for a more in-depth explanation of this, look at option b, they both use the same
audio set-up) use AVIP Pin 2 (right channel), Pin 4 (GND), Pin 3 (left channel) and Pin 5 (GND).
I recommend that you get a cheap Xbox SCART adapter, remove the SCART plug and solder a VGA
plug, for a more in-depth explanation, look at the beginning of option b
After that, go to the section about BIOS’s
Option B
Well, you like me have it a little harder off; you will have to construct a simple circuit that will extract
the sync info from the green. You will need the LM1881 Video Sync Separator semiconductor 2x
0.1µF capacitors (the 2x means you need 2x of them) and a 680kO resistor. Most of this part of the
guide will be taken from [link 3]
Firstly, take the Xbox scart cable, and cut it at the end nearest the Xbox-connector. Holding the end,
pull the metal section out (may be stiff). Remove the metal shielding to reveal the connector. Keep the
section you have cut off as you will need the phono (red/white) connectors and some cable.
Now take your soldering iron and begin to carefully unsolder all of the cables. Note that there is one
loop of wire (connects 2 of the pins directly). Do not remove this loop. All other wires go straight out
the back of the connector, unsolder all of these and remove.
Now take the VGA extension cable, and cut near the male end (the end with pins, not holes). Strip
back the cable back to reveal a bunch of smaller cables within. You need to work out which of these
cables goes to which of the pins on the VGA plug. The best way to do this is to remove the rubber &
glue from the male plug and look inside. Write down which colors go to which pins, draw a diagram if
you think it will help you.
You are now ready to begin the real work! Plug in your soldering iron and give it time to get hot
enough.
Using the diagram and pinout charts below, connect the AVIP (Xbox) port, VGA port, phono plugs
and LM1881 IC together exactly as shown.
Once you have finished this, carefully wrap the LM1881 with insulating tape and put the AVIP
connector cover back on. Make the VGA cable to AVIP join as tidy as possible, use cable clamps
and/or insulating tape if necessary.
That may seem kinda confuseing, so heres another diagram, I’m not quite sute what the switches are
for, I think they are the same as connecting AVIP pins 9, 10, 13, 14
There!
Option C
taken from [link 4]
Using the Xbox's internal sync signals
This method will deliver the best sync signals but is also the most difficult to build. You should have
several years of soldering experience with SMD devices before trying this method.
The digital interface between the NVIDIA GPU and the Conexant chip uses a HSYNC and VSYNC
signal. Unfortunately these signals are only used internally; they are not available on the AVIP.
It's not advisable to use the HSYNC and VSYNC signals directly, since the sync lines of a monitor are
usually terminated with a 75 Ohm load. Instead you have to use a buffer to drive the signals. To make
matters worse, the interface between the Conexant chip and the GPU uses only 1.5 signal voltage.
However, some monitors are able to cope with this.
HSYNC is available at pin 35 of the CX25871, VSYNC at pin 36. I recommend using two Schmitt-
Triggers of a 74HC14 as buffers. The supply voltage of the 74HC14 has to be 1.5 Volt (available from
pin 40 of the CX25871); otherwise the input threshold of the Schmitt-Trigger is too high.
I strongly advise not to solder wires directly onto the CX25871, since you're likely to shorten two or
more pins. The sync signals are also available from two small soldering pads close to the upper edge
of the GPU. Use a multimeter to find them. Pictures of the mother board are [link 5]
Connect the output of the buffer driven by pin 35 of the Conexant to pin 13 of the VGA connector.
Connect output of the buffer driven by pin 36 of the Conexant to pin 14 of the VGA connector.
Since this method doesn't depend on sync pulses embedded in the green signal it doesn't suffer from
the color problems described above.
now, I’m not sure at all about anything in this method, don’t take my word for it, but if you use this
method, you just need to have your Xbox with component video and no special bios, or even a mod
chip I think. I also done have the wiring diagrams for this method, but if your smart enough for this,
I’m sure you can figure it out from the diagrams for the others.
BIOS’s (not for Option c)
Ok, no if you remember, there is no native support for the sync info in the green channel, so, with the
right bios in your modchip, your video encoder will be able to do this. If you have an X3, or xecuter 3
modchip, it’s fairly easy for you, in the video options of the CP live screen, there is a option to turn on
VGA mode, if you don’t have a X3, then you need to get TATX_DEBUG_VGA or
PiXEL8_DEBUG_VGA bios. You can get them here [link 6] .
FAQ’s (yes, I know, most are redundant)
Q: How do I know if my monitor supports sync on green (SOG)?
A: Check the manual, contact the manufacturer, but firstly check if your monitor is listed here [link 2]
Q: My monitor supports sync on green, what do I do next?
A: Build the VGA cable as described, without the sync separator circuit.
Q: I do not have a sync on green monitor, what can I do?
A: There are a few options. Either build your VGA cable with a sync-separator circuit which will
separate the H & V sync signals required from green (see my guide) or you can buy an aftermarket
VGA adapter such as the X2VGA by Neoya.
Q: I've built a VGA cable and I get a picture on my monitor but everything is green! What is wrong?
A: You need to use the TATX_DEBUG_VGA or PiXEL8_DEBUG_VGA bios to correct the colors. If
you are already using one of these, try launching applications / games from Xbox Media Center or
Player.
Q: What Versions of Xbox will work with a VGA cable?
A: So far, there are only BIOS's for v1.0 and v1.1 Xbox’s. If you have a 1.2+ you can try the TATX
bios at your own risk, or buy a VGA adapter such as the X2VGA.
Appendix A AKA “link guide”
[Link 1] http://www.xbox-scene.com/versions.php
[Link 2] http://playstation2-linux.com/sog.php
[Link 3] http://www.xbox-scene.com/articles/vga-cable.php
[Link 4] http://www.xbox-linux.org/Xbox_VGA_HOWTO
[Link 5] Points on top of motherboard- http://members.cox.net/sandman1687/con3e.JPG
Points underneath motherboard- http://members.cox.net/sandman1687/conunde.JPG
[Link 6] Ok, well, this isn’t really a link, if you have any experience in the Xbox underground scene,
you know what “the usual places” are, but if not, read this,
www.xbox-scene.com/articles/xbins.php
sources-
most of the info from the xbox-scene forums or the xbox-linux site, all others are listed in the links
section