PS1 C-sync help

Discussion in 'Modding and Hacking - Consoles and Electronics' started by Bax, Apr 30, 2015.

  1. ynoS XSP

    ynoS XSP Rapidly Rising Member

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    It seems I was wrong.
    The sega 3085 adapter was sold to be used in conjuction with the Megadrive RGB French Model, which in turn had the following modification already done to the motherboard:

    md-fr-csync.jpg

    Pin 11 of the encoder CAX1145 (Comp. Sync out) is routed with a yellow wire to AV port pin 7...

    So, the adapter was not meant to give raw sync signal a proper treatment before reaching television or monitor.
    Unfortunately this leaves me with no more clues about what would be the official solution by sega or sony to make safe use of the raw Sync signal.

    On the other hand, I have been doing some thorough reading to this thread:

    http://eab.abime.net/showthread.php?t=47281

    If we extrapolate the technicalities of the given Amiga example, then perhaps it is all down to:

    -
    Raw composite sync is a digital signal, TTL level of around 5 Volt peak-to-peak which would require the use of a 330 ohm resistor to be safely used by TV or monitor;

    - Since it's a digital signal there would be no need for a capacitor;

    - Although digital, it works being treated as analogue by the majority of TV's and monitors (exceptions exist);

    - Raw Sync (digital) is better for upscalers and professional monitors, whereas Composite Sync (analogue) is safer for our TV's and monitors.

    Any ideas? o_O
    Or better even, anyone with an oscilloscope could please measure the raw Sync signal on the MD, Saturn, PS1, PS2 and DC, please...? :D
     
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  2. snobgamergr

    snobgamergr Spirited Member

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    I'm tempted to perform this mod on my psone console, but I'm not really convinced whether I'll get a better picture or not, as I already have a good quality rgb cable.
    Are there any before and after photos of this mod?
     
  3. ynoS XSP

    ynoS XSP Rapidly Rising Member

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    Hi.

    If you already have a good quality RGB cable then I don't think this mod will give you substantial improvement in picture quality.

    I did notice a difference during video playback, usually cut-scenes or intros (less pixelated), but that's all.

    It is a lot safer and easier to swap CVBS for Luma and use that signal instead for sync, if you have a cheap cable.

    All good cables that use CVBS for sync that I have tried seem to perform just as well, and do without the need for any modifications.
     
  4. snobgamergr

    snobgamergr Spirited Member

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    Thanks for the info! Just as I assumed initially .I'm not missing on something substantial.
    Is there a safe method to check if my cable uses CVBS ? It's kinda impossible to open up the console connector on the scart cable
     
  5. ynoS XSP

    ynoS XSP Rapidly Rising Member

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    I would say 99% chances your cable is wired with CVBS for sync.

    If you manage to grab a switchable in/out scart adapter like this...

    41JRY6JM8AL._SX300_.jpg

    ... then you will be able to quickly check the type of signal coming from the yellow RCA plug.

    If you get a picture with color then its CVBS; If you get a picture but in black and white then it's Luma.

    (Of course I'm assuming your TV/monitor accepts PAL/NTSC encoding on CVBS.)
     
  6. Arnold101

    Arnold101 Active Member

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    instead for a ps1 scph 1000 with pu7 mobo how i have to perform the mod? i can't get to do it
     

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