Will you buy the Kinect?

yes, at launch or during the holiday season
maybe later


Crave Online

Adding Mod Chip Enable/Disable and BIOS Flash ROM Write Enable/Disable Switches To Your XBox (v0.6)

Tutorial written by : Captain Dunsel


There seems to be considerable interest in adding switches to XBoxen these days. Many folks are interested in adding a mod chip enable/disable switch in an attempt to make their XBoxen more “XBox Live friendly”. Folks who opt to flash the onboard TSOP flash ROM (hereinafter referred to simply as “TSOP”) with a non-factory BIOS often want to add a TSOP flash enable/disable switch to minimize the likelihood of accidental flashing.

Even Xodus/Matrix users may wish to add external switches that mirror their on-mod counterparts, allowing them to “change the DIP switches” without opening the box.

The installation of these switches is completely optional. Many folks don’t bother with switches at all… they permanently enable the TSOP write by jumpering the appropriate contacts with solder, and/or they “disable” the mod chip by physically disconnecting it after they flash a non-retail BIOS onto the board. I put the switches in because I wanted to have the ability to change my mind about both of these things without having to crack the box open again. (In retrospect, I think this was a pretty good decision, as lots of folks are now seeing the benefits of being able to turn their mod chips on and off for use with XBox Live.)


Before you read any further, please understand that

1. You are about to make physical hardware modifications to your Xbox. Any mod will void your warranty and potentially fuck up your XBox beyond the point of usability; with hardware mods, this is especially true. Do not go any further if you are at all squeamish about this.
2. While I make best effort to ensure that the information I pass on here is accurate, I have been wrong once or twice in my life. If I do find errors in this document (or are notified of same), I will correct them as soon as I am able.
3. I have attempted to gather together information pertinent to as many mod chips as possible in this document for everyone’s benefit. I have not personally installed all of these chips, but I have taken my information from what I believe to be reliable and accurate sources. If you believe that anything I have written here is incorrect, and you have facts to back that up, please bring it to my attention so that I can correct the document and minimize the error’s impact on others.
4. I am assuming the reader has at least some modicum of understanding about basic electronics (e.g. how a switch works). To make the information useful to the widest possible audience, I have tried to explain things in as simple terms as possible. Bear in mind, however, that explaining to someone how a switch works, or how a pulldown resistor works, or how to solder, is VERY difficult. If you really, honestly don’t understand what you’re reading, please swallow your pride and ask someone who does for some help. Hey, buy him/her a six-pack of beer and see what happens… you’d be surprised how willing your friends and relatives are to help you out, especially if you bribe them enough...

OK, now that we’ve gotten all of the bullshit out of the way, let’s get to it.

Buying the switches

(A note to the electronically savvy: to keep things as simple as possible, I am standardizing on two switches for this project: a DPDT toggle switch and an SPST toggle switch, both available from Radio Shack. Strictly speaking, some of the projects could make do with SPDT switches, you could use rotary or slide or pushbutton switches, you could experiment with momentary contact switches, etc. I am presenting all of these examples using just two types of switches to simplify things and provide a working example to those with less experience. If you think you have suitable switches for the task, by all means use them, but the onus is on you to verify their connections and operation using a voltmeter or continuity tester, and to “map” the connections on your switch to the descriptions I provide.)

For projects described in this tutorial, you may need single-pole-single-throw (SPST) and/or double-pole-double-throw (DPDT) switches. For your convenience, I have identified suitable parts available at your friendly neighborhood Radio Shack store.

The DPDT toggle switches I used (RS part # 275-666) are rated for about three more amps than I needed, but it was all they had in stock at The Shack the day I needed them, and I think they look kinda cool too (with their huge "ON/OFF" label plates). Here’s a picture:

The bottom of our DPDT switch looks something like this:

"on" end "off" end

(The pin numbers are mine, and are added to this diagram for ease of discussion. I don’t believe that the switches I used actually have numbers written on the contacts; your switch may or may not have numbers, and they may or may not agree with my diagram. For the rest of this document, I will be referring to switch pins numbered per this diagram.)

Pins 2 and 5 are the “common” or “wiper” contacts. With the toggle in one position (toward the “ON” end), pin 2 is connected to pin 1 and pin 5 is connected to pin 4; when the toggle is thrown the other way (toward the “OFF” end), pin 2 is connected to pin 3 and pin 5 is connected to pin 6.

For SPST switches, you might use RS part # 275-612, as shown here:

Wiring these is a lot more straightforward than the DPDTs, since you can connect either wire in a pair to either pin. The only thing you need to check is which way to throw the toggle to turn it ON, and which way to turn it OFF.

The rest of this document assumes that you are using the exact switches I did; if you are not, you should use a voltmeter or continuity tester to ensure that your switch works the same way, and “do the mental mapping” for connections if it doesn’t.

Make your wires relatively short to avoid signal bouncing, but long enough so that you can reinstall the motherboard and switches without too much fuss. Due to the fragile nature of connections to the Xbox motherboard, it’s probably a good idea to provide strain relief for your wiring, using cable ties, electrical tape, hot-melt glue, etc.

Switch mounting

This is the only tough part of the process. In order for the switches to be useful at all, the toggles have to poke out of the XBox case somewhere (duh!); unfortunately, the interior of the XBox is pretty tightly packed. You can mount the switches anywhere you want, but obviously they cannot interfere mechanically or electrically with the rest of the stuff in the box.

Fortunately, the left side of the case (when viewed from the front) has open space between the motherboard and the bottom of the DVD drive. I precision-machined the holes for the switches by chewing through the metal shielding with a pair of cutting pliers. The lid was similarly modified using the cutting pliers to chop out a piece of the plastic grating. Not pretty, but effective. However you decide to cut the mounting holes, be sure to remove any metal fragments that may have fallen inside the case.

Here’s a picture of the inside of my case, showing the mounted switches:

After you cut the holes and test-fit the switches, do NOT screw them in. Wait until you have finished wiring them and have reinstalled the motherboard.

Enable/disable for Enigmah, Xtender, or MessiahX

For this project, you will need a DPDT switch. Find your mod chip on the following chart, and make note of the wiring information.

Mod chip
Connect to switch pin 1
Connect to switch pin 2
Connect to switch pin 3
Connect to switch pin 4
Connect to switch pin 5
Enigmah (beta or final)
Chip pin 15
Motherboard connection for pin 15
Chip pin 21
Motherboard connection for pin 21
Chip pin 10
Motherboard connection for pin 10
Chip pin 19
Motherboard connection for pin 19
Chip pin D
Motherboard connection for pin D

As always, check your connections with a voltmeter or continuity tester.

Enable/disable for X-ecuter v1.0 and v1.1

For this project, you’ll need an SPST switch.

As part of your chip installation, you used a piece of wire to connect two motherboard points together (D0 and ground). There are several points on the motherboard where you can do this; here is one example (credit to DaOne and iMurderer for this picture):

The easiest thing to do is simply cut this wire in the middle and solder extensions onto the ends (make sure you insulate the joints with heat-shrink tubing or electrical tape). When adding your extensions, be sure to provide some strain relief when you strip the wires so that you don’t pull them off the motherboard. Then connect the two wires to your switch (doesn’t matter which wire goes to which terminal).

As always, check your connections with a voltmeter or continuity tester.

Enable/disable for homebrew

You’ll need a DPDT switch, a 10 uF tantalum capacitor, and a 10 Kohm ¼ watt 5% carbon resistor for this project. I’m going to refer to this motherboard picture:

and this diagram:

both of which come from Dysfunction’s page and for which he gets the credit. (NOTE: Your circuit may or may not have a connection between pins 1 and 31/32, depending on what type of ROM you are using… If there is no connection there, DO NOT add one.)

As depicted in the diagram, you need to wire a 10 Kohm pulldown resistor between pins 22/24 and 16, and a 10 uF tantalum capacitor between pins 16 and 32. When wiring the resistor, it doesn’t matter which way you hook it up. The capacitor, however, is likely to be polarized. Look carefully at the body of the capacitor; near one lead, it should have a + sign or a – sign; usually, only one lead is marked, but the other lead is (surprise!) the opposite polarity. Connect the + lead to pin 32, and the – lead to pin 16.

Now let’s wire the switch. Referring to the purple notations on the diagram, wire point X to switch pin 2 and point Y to switch pin 3. Referring to the motherboard picture, wire point E# (illustrated with the yellow arrows) to switch pin 1.

As always, check your connections with a voltmeter or continuity tester.

External switches for Xodus/Matrix

The Xodus/Matrix situation is a little different than other mod chips. Basically, you want to add two external switches that mirror the function of the on-mod switches, effectively allowing you to change them without opening up the case. You’ll need two SPST switches for this project.

Assuming that your chip is already installed, be sure that both DIP switches are in the OFF position (i.e. the chip is set for “mode 4”). Then wire the two switches as depicted here (credit to Wiseblood for this picture):

(You obviously don’t really have to use red, green, and blue wires; they are colored differently for clarity in the diagram.)

As always, check your connections with a voltmeter or continuity tester.

TSOP write enable/disable

For the TSOP switch, you’ll have to locate two pairs of contacts on the motherboard. (Credit to SniperKilla for these pictures.) You’ll need a DPDT switch for this project.

For the pair of contacts shown in the first picture, wire one of the contacts to switch pin 1, and the other to switch pin 2. For the pair of contacts shown in the second picture, wire one of the contacts to switch pin 4, and the other to switch pin 5.

As always, (ALL TOGETHER NOW!) check your connections with a voltmeter or continuity tester.


Re-mount your motherboard, being careful not to disturb your fragile wiring job, and mount the switches in the case. Then reinstall the peripherals and button the case back up.

Here is a side view of my reassembled case:

Using a commercial XBox disc and a “non-commercial” disc (such as EvoX), you should be able to easily verify that the mod chip enable/disable switch is working properly. As for the BIOS flash enable… well, it’ll be pretty easy to verify if that is working or not as well.

That’s it! Happy hacking!

Tutorial written by : Captain Dunsel



Giganews Newsgroups