Rapid Fire Mod


First off, I am not the one who created this mod.  Mattie from www.xbox-scene.com created it but his webpage with the info went down.  Here is a link to his page to show its true http://members.home.nl/mattie/xbox/xboxburstmode.html 


Here is the original post of Xbox-Scene about this mod http://forums.xbox-scene.com/index.php?showtopic=322647


This mod makes the controller go into rapid fire when you push the buttons added in this tutorial.  It is great for Halo 2 weapons such as: The battle rifle, covenant carbine, magnums(great with dual magnums), and the energy sword.  Basically it makes the controller think that you are pulling the trigger(s) really really fast.


If you want to put you A,B,X,Y, Black, or White button on rapid fire, use this link


Some things you need to know about some electronic components if you don’t know them already. 


Resistors – They have no polarity so it doesnt matter if you put them in backwards or forward.  They cant be damaged by heat.


Transistors – There are two kinds of them, NPN and PNP.  We will be using NPN.  They can be damaged by heat.  There are three different case styles so that means that their pins may be different in each style of case.  For the transistors in my tutorial, look at the picture below, the bottom line is the Emitter, the middle line is the Base, and the top line is the Collector.


Capacitors – Cant be damaged by heat.  Electrolytic(the kind we are using) have a polarity so if they are put in backwards, they wont work properly.  The positive and negative leads are usually marked somewhere on the body.


LED’s (Light Emitting Diode) – Can be damaged by heat.  Do have a polarity so if they are put in backwards they wont work.  They have a cathode and an anode.  The anode is positive, its also the longer leg.  The cathode is negative, it’s the shorter leg.  If you have cut the legs off already, then the larger part inside of the LED can tell what is what.  The big fat piece inside the LED is the negative leg.  The smaller thin piece is the positive.


Now the symbols for the components.


                                 Resistor       Transistor     Capacitor          LED        Variable Resistor



Part List:




Radio Shack number

R1 (variable resistor)

100k ohm


R2, R5

470 ohm


R3, R4

4.7k(4700) ohm


R6, R7

1.8k(1800) ohm

See below

T1, T2, T3, T4



C1, C2



LED 1, LED 2

Any(of the same ratings)


PB1, PB2











Dont forget your PC board, its not on the list because its too obvious that you need it.


Get all resistors in ¼ watt, they are much smaller then ½ watt.


The 1.8k resistors aren’t available in Radio Shack unless you buy a huge $12 pack of resistors, then you get some.  Just wire a 1k, 470 ohm, and 330 ohm resistor to make a 1.8k.


***These are substitutes for the BC547B, they do work and other people have used them  


If you want your mod to shoot faster then dont use a 47uF capacitors, get 22uF(slightly more then double speed), or 10uF(slightly more then triple speed).


The schematic is a modified a-stable multi-vibrator circuit.  The added parts are drawn in under the red line.  Note that the red line is there to show that the components underneath it are added in, it is not a wire or anything.



This new schematic make a smaller mod.  When I use this mod usually I have the pot turned all the way down so it would shoot the fastest.  So I took out the potentiometer because it only took up room.  The LEDs served no purpose so I took them out.  Now the finished product is smaller then a penny. 



Every time I tested the mod(the old schematic), it didnt work right.  I re-made it 3 times, then thought it was weird that the LED that usually take around 3.3 volts, was getting 5 volts, plus the LED's werent even working.  I switched the resistor and the LED.  After I switched them, it was working great, and the LED's were working. 

Here is a picture of what I mean.

Some helpful information before you start:

*When you go to put the resistors on the board, bend them into an upside down U shape.  This will save alot of space, here is a picture of what I mean:


I saved a ton of space on my PC board by bending them like this.

When you make the jumpers to connect things too far away for just solder, make sure you use insulated wire.  If you dont, it would cause a problem in the end.


When you go to put the transistors on, make sure you know the Emitter(E), Base (B), and Collector (C).  If you got the transistors at Radio Shack, they say on the back which is which.  Here are some helpful pictures that can help ID what is what:

And one last tip, when you put the vairable resistor in.  One side has 2 legs on it, the other side has 1 leg on it.  One the side with 2 legs, clip one off because you only need to connect one or else it might not work as well in the end.

And now for the pictures I took of my first setup and second setup.  The first one was just a bit too big to fit in the memory card port and definately couldnt fit inside the controller.  The second one fit nicely into the memory card port, but I had to sand down the tops of the LED's for it to fit all the way.


Wire ID For First Try

Solid orange - 5 Volts

White and orange Striped - Ground

Striped Blue - Right Trigger

Solid Blue - Left Trigger

Here are the soldering points for the Ground, 5 Volts, Left Trigger, and Right Trigger

Ground and 5 volts


Left Trigger soldering point(its the middle of the 3 legs)

Right trigger soldering point(again, its the middle of the 3 legs)


When you go to put the buttons in, if you got the same ones I did, you need to bend the legs like this:

WIf you are going to mount your switches in the same place/area as I did, then you will need to remove the post circled in black.  It came off with a twist of the pliers.

The rest of the pictures are of the second attepmt I made, its the same thing only smaller, and the transistors that were on the bottom of the last pic are now on the side.


Wire ID for the second try

Striped Green - 5 Volts

Green - Ground

Striped Blue - Right Trigger

Solid Blue - Left Trigger


Since I had my controller already open and I had an extra switch, I added in a crouch switch for Halo 2.  It comes in  handy when playing Halo 2, if you arent playing Halo 2 it doesnt even get in the way.  Link to the tutorial is on the homepage.



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