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Jay is a software guy, so it's normal he chooses a patch solution. It's obvious the cheapest and 'easiest to reproduce' solution once it's working.
Luke Usher had a specific brand of cxbx-r with chihiro support. I don't think it's public, but if you ask him he might give you the link to it.
It basically reroutes the call that communicates with the base board microcontrollers. It also emulates some of the registers in the 0x4000 - 0x40FF range.
I have three broken chihiro at home.

I bought an Xbox motherboard (without HDD) version 1.1 to attemp to fix one of my chihiro.

I got RAM from my chihiro and solder them on the Xbox motherbord. After this operation Xbox motherbord start well (without an HDD after startup I obtien an error message).

I got the 24C02 and the 29F080 from the Chihiro motherboard and replaced ones from Xbox motherboard. After this operation my Xbox motherboard frag :(. I checked my solder and done continuty tests on TSOP chip but all seems fine.

In doubt I took SMC from Chihiro to solder it on Xbox motherboard but same result :(

How can I check my TSOP Bios in place to know if I brooke it during my soldering work ?
you should have tested the xbox board first somehow.
why was it stripped and not sold complete is always a good question to ask.
you also dont know if the parts your pulling from the faulty board are all good.

Thanks for reply.
Indeed I don't know why Xbox motherboard was sold alone but what I known that after memory add, Xbox motherboard was working enough to have no frag.
I can't be sure about parts pulled from Chihiro motherboard because I bought it faulty.
So I would like to know if there is an solution to extract code from TSOP in this situation to check it.
I am waiting an eeprom reader to check the 24C02 (https://dragoncity17.wordpress.com/2017/04/07/xbox-eeprom-reader/)
So you removed the tsop from the chihiro and soldered it on the xbox motherboard.

Did you reprogram the tsop flash before you soldered it 2 the xbox motherboard?

On a 1.1 xbox motherboard you will find a 1MB tsop flash. St M29F080D On very old chihiro type 1 motherboards (with a single row power connector) you might find the same tsop flash chip, but the more modern chihiro mobo's (with a dual row atx style power connector) will have a 29F040 512KB tsop flash chip.

The original chihiro bios can't work on a retail xbox motherboard as one is having an mcpx x2 and the other an mcpx x3.

Tho xbox motherboard is not having a jtag connection that can be used to read out the tsop flash.
So the only option is unsoldering it. You could temporary connect a modchip to the lpc header with an original xbox bios to see if the motherboard boots with that.

Indeed Chihiro and Xbox motherboard I own have an single row power connector and on TSOP of 1 MB.
I did't reprogram the TSOP because on first post I didn't understand that I have to do it.
Could you give me more informations about this procedure.

I ordered an eeprom programmer.

I odered also an Alladin aladdin xt plus2 to test an external bios
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I found this file 29f080.bin in rar file.
So I think taht I have to flash TSOP with this file.
His size on my disk is about 1MB, I think it's version for my 1MB TSOP.
Unless I am mistaken, there are 4 times the same file in a row. I ask the question because my 2 other chihiro have a TSOP of 256 KB.
The procedure described here takes the tsop flash chip and reprograms it with an external programmer. Most such programmers also need a special socket to accept the flash chip footprint.

There is an alternative that came up later on to flash the tsop chip in circuit. This requires the xbox to be soft modded and fully functional. You can bridge 2 points on the motherboard that enable writing to the flash and reprogramming it. It's a pretty complicated procedure that can fill multiple topics on it's own.

When the MCPX chip detects a modchip, it will attempt to boot from it and will disable the motherboard tsop flash. If you try to reprogram a flash, you will reprogram the modchip flash chip. There are some exceptions (special biosses and modchips) that still allow to reflash the motherboard tsop, but the procedure is not well documented and some tutorials claim that part of the on board tsop chip still needs to be intact. (it's contents) Some say it's how microsoft programmed the tsop flash chips during manufacturing.

The chihiro dimm uses the lpc bus as well as a modchip and doesn't work together with it.

This might raise more questions than it answers.
Sorry, I hasn't seen your latest post about the rar.

29f080.bin should be exactly 1MB in size in my case it's 1048576 bytes

Your other 2 chihiro boards should have a tsop size of 512KB and be 29F040

That chihiro tsop flash contains the same chihiro bios twice.
The 1MB bios that is proposed here and should work on a ram upgraded retail xbox board is different.
It contains 4 256KB biosses which aren't identical.
Depending upon it's bios it should basically use the bank 0 bios 0x00000 - 0x3FFFF and bank 3 bios 0xC0000 - 0xCFFFF
The last 512 bytes of the bank 3 bios aren't used either as that memory area is overlapped by the MCPX X3 internal rom.

You will only run into issues if you have a 1.2 xbox motherboard model as that will only have a 256KB tsop flash chip. The board should be able to accept a 512KB chihiro flash chip as well.
Also be very carefull that your board isn't a 1.3 as that has the lframe signal missing on the lpc bus as it's needed by the dimm board. The pin has a pullup resistor to the 3V3 supply rail, so it's difficult to figure out if a board is 1.2 or 1.3 without a scope to test the LFRAME signal.

The last 5 digits of the serial number of an xbox are important. The first digit is the year it was manufactured and the 2 following digits are the week it was manufactured. The 2 last digit are the factory that manufactured the xbox. An xbox from the first 2 months of 2003 or older should be fine. Almost all of those will have a 1MB tsop flash chip and the single row power connector. You might need another power cable between main board and base board if your chihiro mobo had the dual row power connector.

I probably repeated myself here, but's it's important.

Thanks a lot for your reply obcd.

I need to read more than one time to be sure to understand all you explain.
I am waiting my eeprom programmer and my modchip to carry on on my 1.1 Xbox motherboard conversion.

For one of the two others, I have to fix an Xbox motherboard I bought. I have already changed the SMC chip because this motherboard didn't startup at first but now it's frag (reason why I bought an mod chip to test with an external bios). Nevertheless I do not know how to recognize a version 1.2 board from a version 1.3 board. I will check on Intenet to figure out what version is board I already own.
I have to buy another one in order to convert the last one.

Anyway, thank you very much for your help and your answers. As soon as I have received my material and have time to resume the conversion of the first Xbox motherboard, I will come back here to report on the progress of my work.
I tried to read the two I2C bin files get from rar file with LiveInfo but I have an error : This eeprom could not be decrypted. It's perhaps normal but I thought that I can be able to read it with this soft.
With ponyporg I able to open this files.

Someone knows why with LiveInfo I obtient an error ?
The first part of the eeprom contents are encrypted. Liveinfo can decrypt the contents from 1.0, 1.1 and 1.6 eeproms but it can't decrypt chihiro eeproms which use a different encryption key.

This one might be more succesfully:


  • LiveInfo.zip
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Just tried this liveinfo and it was showing me chihiro with an eeprom extracted from one.


  • LiveInfo.zip
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@obcd LiveInfo is bugged and causes incorrect checksums - this is a bug with the underlying XKUtils all of the scene tools used. xbox7887 made a new eeprom editor and it's available on his GitHub. I would actually be very surprised if LiveInfo could open or write a debug eeprom.
  • I only test LiveInfo with I2C binaries extract from darksoft's rar file.
  • I am waiting equipment to extract eeprom from my chihiro boards. I will test LiveInfo with this extracted eeprom. From what I understand from first post I have to modify this extracted eeprom to work with an MCPX X3 and generate an good crc checksum.