Tutorial written by : Jujupinto85

INFO: This guide is only for xbox v1.0 and will not work with so-called multiversion bioses.

Here is my first attempt in writing a guide so bear with me. The other multi-bios guide here is good and a nice foundation, but doesn’t explain at all what to do. I’m not liable if you screw your TSOP, Xbox, or ultimately your life, so good luck. Hopefully from all this gathered info from Xbox-scene and Xbox hacker a noob will be able to make a switch on the TSOP for up to four bios.

****WARNING****
First off, if you don’t have the TSOP flashed or don’t know what I’m talking about, then don’t do it!! TSOP flashing is risky business and probably not worth your time. SO DON’T ATTEMPT IF YOU DON’T KNOW WHAT YOU ARE DOING!!!

1/ The first step is to understand the bios and how it works:

When flashing the TSOP we use a 1meg bios and which for now most bios out there (EVOX, EXCUTER, etc…) make it up with four 256k parts like this:

1Bios256k + 2bios256k + 3bios 256k + 4bios 256k

They can be all the same or all be different.
For example:

Evox 2.5 + x2 4973 + Original + Evox 2.6
Or
Evox 2.5 + Evox 2.5 + Evox 2.5 + Evox 2.5

(Mind you when setup is like this, they are all 256k images).

*As of now, for some reason MultiBios don’t like to work (evox d.6 and x2 4974) with the ORIGINAL installed and just other issue problems, use with Caution*

When flashing with the switches off (no switches grounded) the Xbox reads the 4th quad of the bios, bios 4, by default. More on this later…

2/ The next step is to see where the switches go
They go on back of the motherboard on solder points a18 and a19 and to any one of the ground points:

When you want to split the Xbox’s TSOP into 4 parts you want to make a switch like this:

I recommend the SPST Submini Toggle Switch from Radio Shack # 275-612. Anything will do if it looks somewhat like this:

3/ The next step is to learn how the switches work.

Okay we have made the switches, they are nice looking (or not) and we are ready to go on the next step of learning how they work.
Switch 1 = a(18)
Switch 2 = a(19)
*ON MEANS GROUNDED*

So basically:
Switch on A18 -> OFF= boots 4th bios ; Switch ON = boots 3rd bios.
Switch on A19 -> switch OFF = boots 4th bios ; Switch ON = boots 2nd bios.
Switch on A18 and A19 -> both switches OFF= boots 4th bios ; both switches ON boots 1st bios ; combination of one off and one on yields the above results.

****WARNING****
When flashing the TSOP make sure that both switches are OFF (NOT GROUNDED). IF they’re not, the TSOP flashing will fail because the TSOP cannot be wholly reached, SO MAKE SURE THE SWITCHES ARE OFF!!!

4/ The last step is to make the bios Image:

First we need 4 different (or same) bios images for this purpose we will use this example:

EVOX 2.5 + x2 4973 + x2 4972+ ORIGINAL 4034

To make this a 1 meg file with this setup we go to command prompt (DOS) and type:

copy /b EVOX 2.5.bin+x2 4973.bin+x2 4972.bin+Original 4034.binMulti Bios.bin

After doing this we got our multi bios!! Next boot up EVOX, ftp the Multi Bios, turn all switches OFF, and flash!!

Now you can go on live! with this setup by leaving all switches OFF.

****WARNING****
-Make sure you boot up in correct bios or you may get banned from live! And make sure your Hard Drive is locked while going on Live or even using the ORIGINAL bios or else it won’t work-

Well that was guide, how was it?? Questions?? Comments??
Jujupinto85@msn.com

Credits, Greetz, thanks, and shouts to:
mruell daONE
MURDERER team X-ecuter
ice1138 Rebel-Soul bagel5009 team EVOX
BenJeremy Arakon team Xodus Cheerio slizzap