Noob Question – PAL SNES 60hz mod

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Viewing 15 posts - 1 through 15 (of 17 total)
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  • #24013
    camyoung11
    Participant

    Hi All,

    I’ve got a PAL SNES with HD Retrovision cables, running through my 1.6 OSSC, working really nicely in 2x on my older 1080p Sony LCD.
    I’ve been thinking about tinkering with my SNES, namely working out how to run it in NTSC (240P/60Hz) so that I can play with 3/4/5x modes. (288p/50Hz not working with those higher modes, for obvious reasons)
    I’ve got a SD2SNES, so am able to run NTSC games no problem.

    Which method of 50/60hz mod should I look into? Does the much easier old hardware switch method work with OSSC? or does it cause problems?
    Alternatively, does the SuperCIC mod work well with OSSC? Does anyone have any install instructions that are PAL friendly?

    I’m sorry if this has been asked before… I looked around and couldn’t see a clear answer.

    Thanks so much guys

    #24014
    Steo
    Participant

    I have the basic old switch mod and it still works with the OSSC. The main thing people consider is the dejitter mod for displays that are effected by it, though not all are. https://videogameperfection.com/products/snes-jitter-kit/

    #24017
    BuckoA51
    Keymaster

    SuperCIC works great, remember that unless it’s a 1 chip machine, there’s no replacement oscillator for 60hz so the output refresh rate will be a little off spec. Older Sony TVs in particular can have some severe problems with this.

    #24025
    Steo
    Participant

    It’s worth noting that mine is a 1 chip with the second oscillator also. I thought about getting a SuperCIC myself as the switches can be a bit finicky at times.

    #24073
    camyoung11
    Participant

    ahh, I see. I have a 2 chip – Picture quality is very high though and tracking down consoles in Australia can be a real pain, so I haven’t tried to get a 1chip.

    Thanks for your reply Bucko and Steo, Would going with the more simple mod mean that the refresh rate runs off spec? Does the SuperCIC have the same problem or does the more complicated region mod include an oscillator?

    Would installing the de-jitter mod fix the off-spec refresh rate? I noted already that you can run the de-jitter with the SuperCIC.

    Thanks again!

    #24074
    Steo
    Participant

    Someone else with a SNES done with a switch said theirs reports 59.53Hz while set to 60Hz. It might not matter for certain displays, but some will have issues. My Saturn is modded and runs at 59.3Hz and while it works on the smaller TV I have, it has frameskip on my 4k set. The set also refuses to work in 1366×768 like all of my other consoles, but it gives a picture when tweaked to 1024×768. The problem is that it shows the same frame twice about once per second and it’s actually pretty annoying.

    #24075
    camyoung11
    Participant

    Thanks for that info Steo,

    So am I right in thinking that I can complete the switch mod, then see if my TV is susceptible to issues running slightly off 60hz, and if so, install the de-jitter mod which will bring the sync closer to 60hz which will (in theory) fix it?

    Thanks again for your help guys 🙂

    #24076
    Steo
    Participant

    Apparently the 2 chip model will have the slightly off spec refresh rate according to what I’ve been reading, The dejitter mod will fix the issue with the shorter scanline that causes it to lose sync, but I’m not sure whether that corrects the off spec timing. It says it does fix it for 3 chip models, but I’m not sure if a 2 chip is the same.

    I don’t want to tell you it will work in case it doesn’t, so I’ll try find out more about it and in the meantime, maybe someone that knows more about the 2/3 chip models will get back to you 🙂

    #24095
    marqs
    Participant

    The de-jitter mod has its own crystal so it enables any model to run at vanilla NTSC SNES frequency.

    #24096
    Steo
    Participant

    Even though mine already is 60.08Hz, would that dejitter mod fix the stutter-like scrolling I seem to have? I notice it a lot in Super Mario World regardless as to whether it’s in PAL or NTSC.

    Also I don’t mean to hijack this thread, but I’m finding it interesting now that @camyoung11 has brought it up.

    #24099
    nmalinoski
    Participant

    The dejitter mod is only intended to smooth out the weird sync cadence from the NES and SNES, which can cause some TVs to repeatedly drop sync or not sync at all; it does not affect the 60.08Hz framerate.

    If you want to bring the refresh rate down to 60Hz, you’ll either need to underclock the system to get it to produce a flat 60Hz, like what the Hi-Def NES kit does for the NES, or you’ll need an external video processor to perform framerate conversion (which might get you a different kind of stutter).

    If you’re instead referring to a bit of a shimmering effect when games scroll horizontally, that could be related to SNES games using non-square pixels, which, when displayed on contemporary, fixed-pixel displays, results in uneven scaling (Some pixels are 1px wide, some are 2), in which case you’ll need an external video processor that can interpolate (at the cost of adding a bit of softness). You might be able to work around this with the OSSC by trying different optimized modes in the Line2x settings.

    #24100
    Steo
    Participant

    Oh that makes sense. My 4k set has that sync issue at 2x in 60Hz, but it displays at 3x via 1366×768. It’s that exact shimmering effect I was referring to and I don’t recall noticing it on a CRT, so that makes perfect sense.

    I might play around with it on my smaller TV which accepts those modes, as my 4k set is too fussy to allow the headroom for messing around. Some day I’ll just buy an LG OLED and all my problems will be solved. 😛

    #24134
    Kyusuke
    Participant

    Sorry to also derail the thread as well but wanting to follow up on what marqs said:
    “The de-jitter mod has its own crystal so it enables any model to run at vanilla NTSC SNES frequency.”

    Just to be absolutely sure, if I apply it to my PAL SNES which is currently running NTSC games at 59.53Hz, would the mod allow those games to run at 60.08Hz? I ask since I’m under the impression that NTSC games are running slightly slower than intended (which I’ve noticed has caused long cutscenes to appear out of sync with the music).

    #24135
    Harrumph
    Participant

    Oh wow, it’s true. I didn’t know it had been confirmed to work before! I remember it has been discussed on other occasions in relation to DFO and SuperCIC mod on Assembler forums, but that was some time ago.
    In this solution, the clock is patched in at R73, so PAL uses motherboard crystal while NTSC uses the dejitter board crystal.
    https://github.com/marqs85/snes_dejitter/tree/master/installation/SNSP-CPU-02

    #24150
    camyoung11
    Participant

    Some Awesome conversation happening, so just to make sure i’m right. I’m gonna:

    1) do the older style switch mod on my 2chip PAL SNES
    2) see if my TV will work with it
    3) If not, buy and install the dejitter mod, which should move my hz from 59.53hz to 60.08hz by tapping into the switch and then using the onboard NTSC crystal? (What Harrumph said) and might fix my issues, or at least make it more compatible for when I finally upgrade to a 4k display.
    4) Play some games 🙂

    Hope I read that right?

    Thanks guys!

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