Sega Teradrive CPU upgrade to 486DX.

Discussion in 'Modding and Hacking - Consoles and Electronics' started by Ronnie, Sep 29, 2018.

  1. Ronnie

    Ronnie Spirited Member

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    Life has been hectic but I had a chance to finally test some cpu upgrades in a Teradrive and I can confirm they work.
    After doing some of my earlier Teradrive modifications as seen on this thread: https://assemblergames.com/threads/sega-teradrive-simms-ram-upgrade-help-needed.62782/ I got a hold of some cpu upgrade boards.

    The biggest/huge improvement came with the Rev to 486 board that runs at 66 Mhz. This upgrade board also comes with a socket for an internal Math co-processor. Without it the Teradrive displays as 486SX

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    Once fully populated and as described by the Rev to 486 manual, it brings it to 486DX status.

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    Others tests.
    Sound Blaster Pro 2 test (don't forget the Teradrive lacks the -12V -5V power lines)



    Sega Teradrive in composite video mode so it can run the demo in full color.







    Next in line was the Kingston SXNow (386) upgrade and while it works is on the slower side and there is also one major caveat, while on the socket & due to the aesthetics and board size, some of the cpu upgrade chips make contact with some of the Teradrive board IC's. I was able to still install/test it while the board was inserted at an angle :D.

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    Last edited: Sep 29, 2018
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  2. Bad_Ad84

    Bad_Ad84 The Tick

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    Is that an evergreen cpu? Not seen one for a long long time

    Edit:
    No its not, but looks similar
     
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  3. Ronnie

    Ronnie Spirited Member

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    Yes, the first one is the Rev to 486 (Evergreen Technologies)
     
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  4. 8bitplus

    8bitplus Gutsy Member

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    But will it play Doom :)
     
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  5. CkRtech

    CkRtech Spirited Member

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    Awesome, Ronnie. I would no doubt pursue some of the same PC-side upgrades that you are performing should a Teradrive fall into my lap... somehow.
     
  6. Durandal

    Durandal Spirited Member

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    Unfortunately not, unless we (and by we I mean mostly @Ronnie :p) can figure out how to add more ram. Doom requires 4MB at the minimum and won't even start up unless it detects that much.

    However, I may have an expensive solution to the problem... PM incoming, Ronnie. :D
     

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