Type 3 Pictures

Discussion in 'Chihiro Development' started by tkeahi, Feb 5, 2014.

  1. tkeahi

    tkeahi Active Member

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    Since the pictures are long gone from Parris' thread I thought I'd create a new one showing the guts of a Type 3 Chihiro. Apologies for the not-so-great pics, I'm no photographer. If anyone wants better pics of something specific let me know.

    The MAME chihiro.c file has a good text description of the Type 3 hardware:

    "A Chihiro system consists of several boards. The system is in 2 separate metal boxes that fit together to form one box.
    In order from top to bottom they are:

    Network board \
    Media board / Together in the top box

    Base board \
    Xbox board / Together in the bottom box

    The 2 boxes join together via the Base Board upper connector and Media Board lower connector."

    Overall unit:
    P1000013 (Medium).JPG

    Filter board:
    P1000012 (Medium).JPG

    Top cover removed, looking down at the Network board and Media board:
    P1000014 (Medium).JPG

    Network Board, top view:
    P1000015 (Medium).JPG

    Network Board, bottom view:
    P1000017 (Medium).JPG

    Media Board (aka DIMM board), top view:
    P1000019 (Medium).JPG

    Base board, top view:
    P1000022 (Medium).JPG

    Base board, bottom view:
    P1000024 (Medium).JPG

    Xbox board:
    P1000029 (Medium).JPG
    P1000030 (Medium).JPG
     
    Last edited: Feb 10, 2014
  2. ASSEMbler

    ASSEMbler Administrator Staff Member

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    Great! thanks for uploading them, now they will last forever.
     
  3. Myria

    Myria Peppy Member

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    MCPX X2, 128 MB RAM, Conexant TV encoder, LPC header, 512 KB flash ROM, GPU fan, ATX power supply connection, no USB daughterboard. Weird combination for sure. Curious whether this is the "XBLADE" hardware configuration, which I know is a 512 KB flash ROM debug configuration whose Xcodes are identical to at least one Chihiro model's Xcodes.
     
  4. Myria

    Myria Peppy Member

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    How does the media board attach to the Xbox board?
     
  5. kl0wn

    kl0wn <B>Site Supporter 2013</B><BR><B>Site Benefactor</

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    LPC
     
  6. tkeahi

    tkeahi Active Member

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    The media board plugs into the top of the baseboard (shown below - I didn't take a pic of the bottom of the media board) via the 100 pin connector circled in red:

    base (Small).JPG

    From chihiro.c: "The base board is connected to the XBox board via a 40 pin 80-wire flat cable and a 16 pin 16-wire flat cable connected to the LPC header, plus a couple of thin multi-wire cables which join to the XBox game controller ports (USB1.1) and front panel connector."

    DSCN1147 (Medium).JPG
     
    Last edited: Feb 9, 2014
  7. sonicdude10

    sonicdude10 Insane redneck retro gamer...

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    It looks like a 1.2 or 1.3 based system. Look at the power plug. 20 pin ATX style. That and the Conexant chip says it has to be 1.2 or 1.3 based then. The 512Kb TSOP and 1.0 GPU fan is interesting. We know the GPU fan is there since these boards could be running for days or weeks on end but the 512k chip is interesting.
     
  8. Myria

    Myria Peppy Member

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    What does all the non-Xbox hardware in a Chihiro do, anyway?
     
  9. JayFoxRox

    JayFoxRox Spirited Member

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    It's pretty common Sega arcade hardware. Basicly Sega released Naomi 1 and also worked on the "Naomi GDROM System" which eventually was released for Naomi 1 (DC), Naomi 2 (DC), Triforce (Gamecube), Chihiro (Xbox) - all of those use GDROMs and probably the same parts.

    The GDROM system replaces Sega ROMs / Cartridges by using the GDROMs which were also used in the Dreamcast. You use a drive and connect that to a DIMM Board which is basicly just a glorified cartridge with battery backed RAM instead of ROM. Normally you install to it using a GDROM Drive, but there is also a NET DIMM which can get the game through network.

    To access that RAM/ROM you need a baseboard which contains the frontend for the console (Once the game console boots from internal rom the frontend is launched. This is commonly called segaboot and will usually display the logo of the platform and provide a system test menu). The baseboard should also contain an EEPROM which stores all global settings.
    The most important feature of the baseboard is probably it's serial port and JVS port. These serial ports are probably RS485 or RS232 (judging from Lindbergh knowledge).

    The Filterboard is connected to the baseboard and provides a socket for a PIC16 security IC which answers very simple challenges. tmbinc reverse engineered the protocol on his blog.
    It also contains 2 hardware buttons (?) and status LEDs.

    Then there is also a network board which is used for network play (not sure if it is used on Chihiro as Xbox already has Ethernet).

    All of it together is what they call "Mediaboard" I believe.

    From the software side on Xbox, the baseboard is presented as "mbrom:" for the firmware I believe (read below), "mbcom:" communication port (JVS or serial, still unsure which) and "mbfs:" (practicly access to the FATX image stored in the DIMM board).
    Both filesystems have a new driver which only exists in the Chihiro kernel.
    There is also an LPC I/O register space (0x4000-0x4FFF) which can be used to query DIMM size, boot.id (?), hardware revision etc.

    There are 2 versions of the baseboard OR networkboard (can't remember): one with an FPGA and another one with an ASIC. tmbinc also talks about this in his blog.
    On Chihiro every (?) game comes with 2 Firmwares, I assume one is for each version. The Xbox board is able to upload a firmware through the LPC space it seems.
    I'd assume that the Firmware is actually part of the game and controls the "mbcom:" port. So a game with force feedback might talk different to "mbcom:" than one which only needs JVS input.
    It appears that the JVS stack is running on the Xbox board for at least some games (On Lindbergh the JVS stack is also staticly linked into the games which communicate with a custom kernel module, so this is probably the case, I just didn't verify it yet)

    So the same as with Lindbergh: The Sega hardware is entirely useless.
    - The JVS stack on Lindbergh is absolutly horrible and input can easily take 50ms to even reach the game (independent of I/O board). JVS could probably done using a tiny JVS to USB adapter on Chihiro and Lindbergh
    - The DIMM Board is useless because the Chihiro could also simply use an Xbox HDD or DVD.
    - The Network Board is useless because the Xbox board also has a Network out
    - The Filterboard is useless because the security IC is insecure (It's not even a security IC to be honest), 2 hardware buttons also exist on Xbox and Xbox also provides 2 LEDs. (If Sega really wanted the IC they probably could have put it on their JVS to USB interface)

    I'd assume you can turn an Xbox into a Chihiro by running custom code and a 1 microcontroller board which hooks to the USB port (for less than $10 + a lot of work).
    Talking from experience, Lindbergh games also run on a standard Linux PC with no loss in features and better performance / less input lag (Even replacing the actual audio hardware with software emulation is faster because Sega+Creative suck so bad at writing custom drivers - tiny loss in features though, but unused in almost all games anyway)


    //Edit: Is anything connected to USB on the Chihiro Xbox board? If so, where does it go to (baseboard probably?) and did you try connecting that cable to a PC yet?
    I just had a crazy idea that the Chihiro might actually be a full USB-setup internally.
     
    Last edited: Feb 8, 2014
  10. nonosto

    nonosto Intrepid Member

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  11. tkeahi

    tkeahi Active Member

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    Version 1.0 (?) Earlier Chihiro motherboard

    I just picked up another Chihiro...broken, won't boot...so I pulled it apart and the xbox board looks to be an earlier variant.

    Overview:
    IMG_1829.JPG

    Early-style power connector:
    IMG_1830.JPG

    1MB TSOP:
    IMG_1832.JPG

    Monster clock cap and MB Rev K mark:
    IMG_1827.JPG
     
    Last edited: Mar 1, 2014
  12. NeC5552

    NeC5552 All your skullz are belong to us.

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    I wonder one of those Xbox boards could be used in a normal Xbox board.A chip would be required though,for installing a new HDD.
     
  13. TriMesh

    TriMesh Site Supporter 2013-2017

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    You probably could, but it's a lot closer to the board used in the debug kit than the retail one. The RAM is 128MB and the MCPX is a MCPX X2 - both of these are the same as the debug (the retails have 64MB and a MCPX X3). One of my friends fixed a debug kit with a (physically) damaged board by taking the flash and eeprom from it and soldering them onto an arcade PCB.
     
  14. NeC5552

    NeC5552 All your skullz are belong to us.

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    Was the replacement arcade PCB from a Chihiro?Or was it a board taken from and Xbox arcade system?
     
    Last edited: Mar 29, 2014
  15. tkeahi

    tkeahi Active Member

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    Ive been trying to cook up a retail-style BIOS that will work on a modchipped chihiro, but so far I've had no success.

    Like TriMesh said the Chihiro xbox board looks to just be a devkit/debug motherboard with a different BIOS/ EEPROM flash.
     
  16. nonosto

    nonosto Intrepid Member

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    Soyandroid, succes to flash a debug xbox motherboard with the Chihiro bios to repair a Chihiro system. I try to load chihiro bios with a custom phoenix bios loader but black screen, Ithink because some card missing and I dont know how to integrate the segaboot.xbe.
     
  17. TriMesh

    TriMesh Site Supporter 2013-2017

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    It was from a Chihiro - but the boards are marked "xbox arcade" - as far as I know, the only xbox Arcade system is the Chihiro.
     
  18. HEX1GON

    HEX1GON FREEZE! Scumbag

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    tkeahi may I use these photos you've taken for the XBOX Archive?
     
  19. tkeahi

    tkeahi Active Member

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    Of course! Let me know if you need other pics, I still have the 2 chihiros sitting here.
     
  20. HEX1GON

    HEX1GON FREEZE! Scumbag

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    Thanks for that :)
     

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