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Has anyone Converted an Original Xbox to a Chihiro?

twistedsymphony

twistedsymphony

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So the Chihiro main board is literally just an Original Xbox Motherboard. comparing this to an Xbox Motherboard it's got a GPU fan which is normally an indicator of a V1.0 motherboard, but it also has a 2 row power supply connector which makes it more likely to be a version 1.2 or 1.3 motherboard. the Chihiro cap layout and chip models seems to confirm a v1.2 or v1.3 revision since it uses a Conexant Video chip (they switched to Focus with v1.4 and up) and the capacitor layout matches that of a v1.2/v1.3 as opposed to that of a v1.0 or v1.1.

The Chihiro has 128 MB of ram as opposed to the 64MB on the original Xbox but from what I understand upgrading ram is just a matter of sourcing the chips (from an old GeForce 2 Graphics card or another Xbox) and soldering them onto the empty slots, then updating the bios. I'd suspect that the Chihiro has it's own custom bios, I know the early 1.0 and 1.1 Xboxes had a 1MB bios chip while newer versions only have 256KB So I'd be curious of the Chihiro Bios size and if the TSOP would need to be replaced as well.

In short: I'm wondering if you got an Xbox 1.2-1.3 mobo, added the necessary ram then flashed the Chihiro bios if it could serve as a replacement Main board in a Chihiro.

I mean, is there any other differences that would prevent this from working?
 
No idea personally, but I'd love to learn how feasible something like this would be.

I'm curious, though, is it the onboard RAM on the Xbox motherboard that comes into play here or is it more a matter of RAM in the media board? The same Xbox motherboard supports both 512MB and 1GB from the media board (at least in a Type 3).
 
AFAIK it's not 100% a normal xbox but rather a developper version which has more main Ram and Video Ram. Those can be easily converted, but I'll let @android elaborate on this if he wants.
 
Also, there's a Chihiro bios floating around. I just found it on emuparadise. It's labeled as chihiro_xbox_bios.bin and is 512KB.

It's been forever since I've messed with hard-modding an Xbox and flashing the bios, but IIRC, on the earlier ones you could address different sections of the bios by way of a switch. I can't recall if you could utilize 512KB at one time, or if it was limited to 256KB chunks.

If you have an XBOX with this capacity, it might be worth flashing the Chihiro bios and see what it outputs on a TV. I believe a Chihiro will output to a TV over other video signals with an Xbox video cable, but with give an error code, so maybe you could verify if it works on stock Xbox hardware before hard modding RAM.
 
android said:
A normal Xbox can not be used for Chihiro.

Chihiro is using a Dev XBOX like motherboard.

The diference is the MCPX Nvidia chip, the one that holds the crypto keys.
Click to expand...
Android dixit (Android has spoken)
 
Well, all is possible but you will need to get a Development NVIDIA MCPX chip that is a BGA chip, and swap it, also flash the board with Chihiro BIOS and also add 64Mbytes more of ram.

Will be more easy to get a Dev Board, the Green ones and just flash chihiro bios there.
 
Thanks for the clarification. Bios and Ram are straight forward changes but the MCPX difference kind of kills it.
 
The chihiro bios is 256KB. The version floating arount on the internet is 512KB, but it consists of 2 identical 256KB blocks. it's basically just a copy of the flash chip.
In the high days of xbox, you could use the Phoenix Biosd Loader to load a "modified" debug bios on a retail xbox. Is there a reason why it wouldn't be possible to mod a chihiro bios so that it would run on a retail board? I know that a using a devkit mobo is easier, but devkits are way more expensive than retails. Chihiro mobo's are nearly impossible to find (working) unless you buy a complete unit.
 
Well just find an Xbox hacker, that wants to expend 6 months of his free time, reversing the Chihiro Bios and porting it to a normal xbox board.

Once that is done, he will need to work also on the Base Board and Media Board Firmware and patch all the signature checks.

Once that is done, he wil need to work also on the Ethernet comunication board.....
 
aint-nobody-got-time-for-that-300x300.png
 
Would you really need to reverse the bios? A xbox bios consists of several known parts. First, there is the upper 256 bytes which is the mcpx secret code on a retail board with a mcpx rev 3 and simply the bios code on a debug mcpx rev 2. That code is running the xcodes which are known to be different between retail and debug. Next, the 2bl area is hash checked. After that, control is passed to the (unencrypted) fbl part that decrypts 2bl into ram. 2bl also hash check some areas of the bin (like the xcode part) and decompresses, decrypts and loads the final kernel into ram. Finally, the kernel code is started.

All those protections are identical on xbox bios and chihiro bios. There already exist methods to bypass all that security. Most of the 6 months work is already done I would say.

The actual kernel part is what is different between a normal xbox and a chihiro, but that should be usable without the need for reversing, unless it has some buildin checks that verify the mcpx chip mounted on the board. If such a check would exist, the bios shouldn't run on the xqemu xbox emulator either, as that code simply emulates a mcpx3, and it makes it to the chihiro logo. So, at least, a modified chihiro bios (with retail xcodes and the 2bl that is used in modchip biosses.) should be able to make it to that logo as well.
The emulator shows a mainboard error 2, but that might be due to the missing baseboard emulation.

Some chihiro games even run on a retail xbox mobo with 128MB ram. They function without baseboard, mediaboard and network board.

Lots of stuff was considered impossible till someone proved otherwise.
 
I'll be glad to see either an xbox converted to chihiro or either a chihiro running xbox games. Both would be a big success.
 
Any good xbox hackers around here with a bit of spare time?

Another difference between a retail unit and a debug unit is the pic processor.
A retail unit uses a challenge response between that processor and the bios. If the pic doesn't receive that sequence within a fraction of a second (like 0.1 - 0.2 sec) it will reboot the x86 core. This is something you see when you have a bad tsop flash or a broken modchip install. The xbox fan's stop for a fraction of a second a couple of times.(Looks like the power is shut down to force the reboot.) After that, you get the famous frag (flashing red and green) indicating something is broken. The strange thing is that a chihiro mobo shows a very similar behavour when it's gpu got toasted. No idea what is responsable for that. Maybe it's triggered from within the kernel and instructed to the pic.
 
Darksoft said:
chihiro running xbox games.
Click to expand...
Could a potential solution for this be as simple as using a hacked Xbox mobo inside a Chihiro case, plugging up all the other boards? The Chihiro has what I would assume is a JVS to Xbox controller conversion, but maybe the Xbox would be lacking JVS output commands to drive the I/O (unless those are independently managed off of the mobo)?

As cool as it might be for Chihiro to run Xbox games, I guess there's probably not much motivation. Someone determined to play Xbox in their arcade cabinet can do so without having to go the Chihiro route, and do it much cheaper.

Xbox converted to Chihiro would be a little more valuable from a preservation standpoint, but I'd guess motivation from those capable of doing it isn't really there. From a driving game perspective, both Crazy Taxi and Outrun 2 have ports on the Xbox. WMMT 1 and 2 would be the main Chihiro exclusives and they're probably not popular enough to motivate someone to work on a conversion.

Other Chihiro games:
HOTD3 - It got an Xbox port...
Ghost Squad - Wasn't it on the Wii?
Virtua Cop 3 - Wasn't it ported? I'm thinking I have it on some PS2 compilation.
Ollie King - I don't know much about this one. Not sure if ported... not sure if worth playing on a cabinet lacking the dedicated skateboard controller.
Gundam: Battle Operating Simulator - I don't know much about this one. I think it's only available in 1GB flavor. Does that make it less possible to run on an Xbox?

So I'd guess exclusives you might get are:
WMMT 1 and 2
Gundam: Battle Operating Simulator
Ollie King


obcd said:
Any good xbox hackers around here with a bit of spare time?
Click to expand...
That's certainly out of my realm of expertise, but I'd be more than willing to participate in testing. I've got a couple Xboxes and one is modified with switches to let me choose different bios banks, so I could potentially recover from an incompatible bios flash.
 
I also think most value would come from using a standard 128MB modified retail mobo in a chihiro case together with the other chihiro boards.
A dedicated racing cabinet like outrun 2 has steering force feedback that makes it more fun to play.
If a chihiro mobo breaks, the only current solutions are buying a coplete unit for 400 quid or looking for a debug unit which is expensive as well. A second hand xbox sells for 50 and the additional ram costs maybe 10. Fact is, they do break, usually due to an overheating cpu which is hard to repair.

Running xbox stuff on a chihiro could be usefull for people having a dedicated cabinet with a chihiro. It might allow them to play more games on their unit without the need to swap hardware and change cabling.
 
There was a guy selling a RAM upgraded Xbox on eBay. The listing claimed that it could run Chihiro games after dismissing a few error screens. My eBay search-fu is weak and I can't seem to find it. Perhaps we could reach out to the guy and see what's up.
 
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