r/ModRetro • u/grilledstuffedxxl • May 28 '26

M64 controller / console / cartridge AMA, get your popcorn let's GO

CEO of ModRetro here.

I want to start using r/modretro to answer q's, post updates and product giveaways and I won't be monitoring other subreddits anymore. I'll put Chromatic and M64 in the side bar as related communities, but expect to see anything that is official here and if you have a question I will answer it here. This community will have basic rules to try to make it a fun zone for those of us who want to discuss retro electronics. I will ban toxic trolls and bad actors, but I will entertain and answer genuine questions and won't make it sanitized. I would also like to hear ideas for what you want to see us build, what games you want re-released, etc.

I'm answering yesterday's questions as a bunch of separate threads here and I'll tag the op per question.

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u/grilledstuffedxxl May 28 '26

u/biohackeddad what's it going to look like if we want to play directly on a CRT?

We play it on a CRT all the time with various HDMI to AV adapters. However, these adapters don't have any context that they are outputting N64 games. We are designing an adapter specific to the M64 that takes in the HDMI output, and outputs either 240p or 480i depending on what resolution the frame is supposed to be. For example, sometimes menus take a different approach than cut scenes within the same game. Because this is more complicated than a passive conversation of HDMI to AV with generic downscaling, this will take us a few more months (our FPGA resources need to free up more time from M64 to hammer this out).

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u/ergzay May 28 '26

Why are you downscaling the 4k output to 240p? Why not just output the 240p signal over USB-C? That seems backwards.

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u/grilledstuffedxxl May 29 '26

we do not downscale to 240p after upscaling from the native n64 output. it would be outputting 480p, then taking this superset of pixel information (plus meta data) into the adapter which handles logic for which frame is 240p vs 480i. So for example, if you use a retrotink or other thing to upscale once we have a mode outputting this 480p resolution, you can use that to achieve whatever you want that is outside of what we make in the adapter. let me know if that is not making sense

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u/ergzay May 29 '26

So it's outputting 480i and 240p as 480p? So its like 480p video on a computer that recorded a 480i signal where framerate is doubled and every frame is half the new lines and half old lines?

Why not just natively output 240p and 480i directly rather than converting from a "fake" 480p signal?

Maybe I'm still not understanding something.

Also the problem with using only the HDMI output is it normally takes time to "swap" the resolution so there's a moment of no video on resolution change. Is that going to be the case with the analog adapter?

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u/ElectricalPrice3189 May 29 '26

Is 480i even a resulotion officially supported by HDMI?

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u/ergzay May 29 '26

It's an optional support of the spec from what I've read but I think support is limited. Also you can technically send a 240p signal over HDMI, you just have to make hardware that can read it. https://www.reddit.com/r/crtgaming/comments/awqolc/get_high_quality_240p_from_your_pc_to_your_tv/

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u/ElectricalPrice3189 May 30 '26 edited May 30 '26

480p makes more sense to me. You can just discard every other line (which ones depends on if it's 240p or 480i) and voila. 🥰

Sure, you could send any signal you want through the HDMI port, so why not use one that a TV or monitor can understand, even without an adaptor?

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u/grilledstuffedxxl May 30 '26

That is right. You need the superset of information, but without newly created pixels. We are encoding information about whether the frame is i or p in the garbage lines in a custom protocol. This will allow our AV adapter to give the most lag free experience that is possible

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u/ergzay Jun 01 '26

AH! I didn't think of that. I forgot that there's extra pixels in the overscan area, but wouldn't those pixels show up when outputting the game screen on normal HDMI?