PSP 3000 (and Go) "interlacing" mystery solved!

Discussion in 'User Submitted News' started by Ryccardo, Sep 2, 2019.

  1. Ryccardo
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    Ryccardo and his tropane alkaloids

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    psp.

    When the third major revision of Sony's PlayStation Portable, chiefly the PSP-3000 "Brite", was released in 2008 as a successor of the PSP-2000 "Lite", many upgraders quickly noticed a quirk of its upgraded display: noticeable artifacts between lines.


    Probably due to confusion with another innovation of the 3000 series (the ability to display games and applications on an interlaced external display, whereas the 2000 series only supported interlaced output for media files played via the XMB), the misconception that the console uses an interlaced LCD quickly hit discussion avenues and still circulates to date, despite pictures like the above one quickly circulating and suggesting other factors like the subpixels having been rotated horizontally.

    It was only as of yesterday that Reddit user "niinono" embarked on a scientific approach of identifying the panels and comparing their datasheets, coming up with some other revelations (such as the 2000 and E1000/Street models being potentially brighter than the 3000 and N1000/Go models, despite the latter having superior contrast ratios and better response time), but perhaps equally as interestingly, he formulated (with the help of a post on the System11 gaming forums) a plausible hypothesis on the issue:

    As many people who serviced Nintendo handhelds with a color display know, there is an adjustment for each screen's bias voltage (officially termed "flicker" and popularly but incorrectly called "contrast" or "scanlines", located next or under the battery until the 3DS which switched it to being a software adjustment), which if misadjusted produces a similiarly distorted image and may increase stress on the panel's electronics; and every model of PSP exhibits this issue due to the lack of this setting (using instead a fixed default value), which the increased performance and horizontal subpixels (less ideal than vertical ones for most Latin alphabet characters) of the 3000 and N1000 models can only exacerbate.
    :arrow: Source and discussion on Reddit

    Picture credit: Xythen of Wikipedia
     
  2. Ryccardo
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    Ryccardo and his tropane alkaloids

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    1 sentence executive summary:

    Apparently it's not only the PS1, PS2, and PS3 that Sony cheaped out on at the expense of quality!
     
  3. MrCokeacola

    MrCokeacola GBAtemp Fan

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    Crazy I just got a 2000 the other day after only owning a 3000 for years...

    Still doesn't mean much as I play all my PSP games on my OLED Vita anyways but you know.
     
  4. Ryccardo
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    Ryccardo and his tropane alkaloids

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    Ahh, I tried but couldn't stand the choice between laggy filters or bad upscaling :)
     
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  5. HRudyPlayZ

    HRudyPlayZ GBAtemp Regular

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    You can still use the original resolution and ratios with filters disabled x)
     
  6. The Real Jdbye

    The Real Jdbye Always Remember 30/07/08

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    So does that mean the issue is fixable with a simple hardware mod? (Soldering a resistor or a pot to some pins)
     
  7. Ryccardo
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    Ryccardo and his tropane alkaloids

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    It can likely* be improved, of course it's not going to rotate the pixels :)

    * I haven't seen the datasheets (or a typical implementation of a bias control system) so hopefully this fixed default is generated on the motherboard and not directly inside the panel, and if an higher voltage than whatever's there happens to be the correct one, have fun stuffing an inverter in the case (probably possible if you also do a replace-UMD-with-custom-battery mod, lol)
     
  8. The Real Jdbye

    The Real Jdbye Always Remember 30/07/08

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    A boost regulator should do, you can find them in pretty small packages.
     
  9. Sakitoshi

    Sakitoshi GBAtemp Official Lolimaster

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    behind a keyboard or a gamepad
    I have a psp go and a friend had a 3000 and have never seen a single artifact in either screen.
    I do see (with the aid of my phone camera) that the pixels are horizontally aligned like you say, but the density of the screen is still high enough to not be able to notice with the naked eye unless up close and actively looking for them.
     
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