PC- FX[GA] RGB mod?

Discussion in 'NEC PC-88 and PC-98+ PC-FXGA' started by Uroko Sakanabito, Dec 27, 2017.

  1. Uroko Sakanabito

    Uroko Sakanabito Spirited Member

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    Any idea if someone ever did this?
    Would love to hook up my PCFXGA directly to the OSSC
    S-Video and video output suck :-(

    PS: Are there any tools to use the PAD with PC98 games?
     
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  2. Taijigamer2

    Taijigamer2 Gutsy Member

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    As the PCFX-GA is a rare and obscure device, I doubt it has garnered enough attention to get an RGB mod. I read somewhere that the encoder only outputs S-Video.

    The pics online are poor quality. If u could get some hi res pictures of the circuit board, I could look and see if a mod is possible. Most analogue video encoder needs to get Digital RGB or YUV from the graphics chip so this can be fed to another (mod) encoder which can output RGB.
     
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  3. Uroko Sakanabito

    Uroko Sakanabito Spirited Member

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  4. Taijigamer2

    Taijigamer2 Gutsy Member

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    Ok so after a quick bit of research, there seems to be 2 different encoders responsible for converting digital graphics information into analogue video. The HuC6260 (in pc-engine/turbo grafx) and the HuC6261 (pcfx/ pcfx-ga).

    Do you have a pcfx or pcfx-ga? Which video encoder does it have?

    The huc6260 can be modded with a pc-engine RGB amp mod. The huc6261 is reported to not have RGB but I believe this to be a misunderstanding of the limited information.

    If u are handy with a multimeter u could check pins 44, 47, 49 and 51 for voltages.
     
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  5. Uroko Sakanabito

    Uroko Sakanabito Spirited Member

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    I only use a PCFX-GA, its a C-Bus board used in pc9801 (there is also a DOS version).
    Can take pictures when i find the time to take it out again.
    Will post them here :)

    Thank you very much so far for your help !
     
  6. Uroko Sakanabito

    Uroko Sakanabito Spirited Member

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  7. Taijigamer2

    Taijigamer2 Gutsy Member

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    Good find. Looking at the pictures, the huc6261 is a different package from the huc6260 so it's going to definitely have a different pinout. This is going to complicate things as I was hoping they shared the same pinout.

    This thread http://fullmotionvideo.free.fr/phpBB3/viewtopic.php?f=2&t=329 mentions the huc6261 only outputting YUV and s-video but I think the information has been misunderstood. The available info on the huc6260 shows that it receives digital YUV and converts to analogue RGB (from which we can get s-video and CVBS) so my theory is that the huc6261 operates the same way and we can hopefully find analogue RGB pins.

    The hard part is finding those pins without a data sheet. If u are handy with a multimeter, u could take voltage readings of the huc6261 pins while a game is playing (a fixed screen with balance of red blue and green to minimise variation in voltage level). An oscilloscope would be the most useful tool for this task but a digital multimeter might suffice.
     
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  8. Uroko Sakanabito

    Uroko Sakanabito Spirited Member

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    i think i buy a loose one and send it to a friend with the required skillz :)
    Should be worth at least a try !

    Thank you for all the information that helps very much !
     
  9. Taijigamer2

    Taijigamer2 Gutsy Member

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    No worries. I think there's a good chance that it is possible. All u will need is a digital multimeter and or an oscilloscope to find the required RGB and CSYNC pins. Maybe send it to someone with the required skills and equipment. I would offer to do it if u were in U.K. But I doubt there are many pcfx-ga outside of Japan.

    PM me if u decide to give it a go.
     
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  10. Uroko Sakanabito

    Uroko Sakanabito Spirited Member

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    Sending the FXGA is no problem but sending the PC9821 +FXGA is hell ^__^
     
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  11. Uroko Sakanabito

    Uroko Sakanabito Spirited Member

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    [​IMG]

    i have to say, its "ok" via SVIDEO and this little LCD so maybe i can live with that picture.
     
  12. Taijigamer2

    Taijigamer2 Gutsy Member

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    S-video is ok, better than Composite. The games should still look pretty good.

    I looked into the pcfx-ga, an intriguing piece of hardware. I love the old legacy PC Card addons but the chance of running one outside of Japan is next to impossible due to it needing a pc-98 to run. If I do ever acquire a pc-98 + pcfx-ga I'll look into an RGB mod.

    I'm on the lookout for a 486 pc and creative Labs 3DO blaster which is sort of a western equivalent.
     
  13. Uroko Sakanabito

    Uroko Sakanabito Spirited Member

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    There is also a Dos version of the PCFX-GA :)
    Should be possible to install them here without problems.

    I was thinking about building a 3DO Blaster in my FMV Towns but the card price is very high these days :-(
     
  14. Uroko Sakanabito

    Uroko Sakanabito Spirited Member

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  15. Taijigamer2

    Taijigamer2 Gutsy Member

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    Damn. Now I have to get one.

    Interesting read. The 3DO blaster is a ball ache to setup because it requires so much legacy hardware. I've got an FZ-1 but the 3DO blaster is interesting because it outputs over VGA. It's a shame they are very rare and so expensive. I keep an eye on eBay incase someone is selling an old pc with creative Labs tech.

    It would be nice to build a pc with both isa cards installed.
     
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  16. Uroko Sakanabito

    Uroko Sakanabito Spirited Member

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    The idea is great but that needs a lot of money and time ^__^

    @FXGA could finish Zeroigar via SVIDEO and it looked very good on that tiny screen.
    [​IMG]
    Rest of the games do scroll far slower so everything fine :)

    Had a Ram error at bootup just to find out that FXGA saves to floppy disk...
     

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