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Converting 480i to 240p with the Extron Interface trick

Some years ago now, Tobias Reich (Fudoh) wrote an excellent page about down-scaling content to 240p, which can be found here.

In the latter part of that page, Fudoh talks about Extron RGB interfaces. These little sync processing boxes have all kinds of potential uses in a retro gaming setup, but one use that always seems to confuse people is the undocumented 480i to 240p conversion trick.

In a nutshell, by some quirk of their design, the Extron interfaces can convert an incoming 480i signal to 240p by the flick of a dip switch. It almost sounds too good to be true and indeed, there are some caveats. The trick only works on classic CRT monitors. HD CRTs, CRTs with their own signal processing or any kind of external upscaler or line doubler isn’t going to be compatible with this method.

Several people have reported they have tried this trick with their classic CRT displays and got it working, while almost as many say it doesn’t work at all for them. Having recently acquired a CRT we decided to give it a go for ourselves. We hooked up an Extron 203RXI RGB interface between our PS2 and a Mitsubishi Megaview CRT. Starting the PS2 in interlace mode we loaded the PS2 port of Espgaluda. Once the game was loaded we reached for the DDSP switch on the Extron and flipped it down.

Rather than a lovely 240p progressive image, our CRT showed a picture full of digital garbage. You could just about tell it was Espgaluda, but it wasn’t at all playable and certainly not what we were expecting.

Undeterred, we decided to try some different models of Extron Interface and we did eventually find one that worked with this trick, the Extron 580xi. With the 580xi we got a great 240p image complete with scanlines, just as promised.

In summary, if you want to convert 480i to 240p on your classic CRT monitor or television, look for an Extron 580xi RGB interface and avoid the 203rxi and 109xi models. The 203rxi models do have a lot of internal jumpers which can be configured by removing the units case so it is possible that a certain configuration would work for this trick. If anyone is aware of how to configure the 203rxi or other interfaces for this purpose, please let us know in the comments.

19 comments

  1. Wayne says:

    How did you hook the PS2 up to the Extron 580xi? You need some sort of SCART-to-VGA cable (looking at the front of the Extron)? Where are those sold?

    • BuckoA51 says:

      I connected through an Extron Crosspoint switch, you could also use something like the ArcadeForge Sync Strike.

      • Wayne says:

        Shame there’s not an easier/more convenient method; I think Retro Gaming Cables once sold a cable that would’ve facilitated hooking SCART directly up to this, but no longer.

        I assume a Crosspoint requires mains power(?), so you’re looking at two additional bits of kit to power in order to get this working (the Crosspoint and the 580xi).

  2. Andrew Kepic says:

    Are there any specific settings for the dip switches?

    • BuckoA51 says:

      DDSP needs to be off.

      • Andrew Kepic says:

        Okay. Thanks for the tip. And thanks for posting this guide. I’ve tried converting 480i to 240p in the past. I followed Fudoh’s recommendation of an Extron RGB Interface paired with an Extron VSC. Unfortunately, even with Fudoh’s guidance, I was unable to get a stable picture on my CRT monitor with the VSC/RGB interface combo. But if you were able to get it with just this interface unit alone, then I’ll give it try. Luckily I was able to find one on ebay for under $40 USD. And this particular model is really small compared to other models so it won’t take up much space.

        • BuckoA51 says:

          May also need composite sync mode too. My CRT is a Mitsubishi Megaview. Good luck!

          • Andrew Kepic says:

            Well, I got my 580xi today and have it hooked up to my monitor which is a Sony BVM 20-F1U. I connected my PS2 to it using a Sync Strike. While I do get picture, it still displays in 480i. I left all of the dip switches off except for composite sync. Any ideas on what else I can do to get 240p out of this thing?

  3. SavagePencil says:

    Can you post a pic of what you saw? I’m running a VSC 900 (1080p/720p/480p -> 480i) into a 203rxi (480i -> 240p) and it looks fantastic.

  4. BuckoA51 says:

    Photographing CRTs is hard, the image was warped and twisted and was basically just garbage.

  5. West says:

    Just picked up an 202rxi and am looking to do this exact conversion for PS2+Xbox360 into and Egret2. Crossing my fingers it works but if not then maybe an 580 will do it. Thanks for the info.

  6. Wayne says:

    Might this technique work without an Extron Crosspoint or additional kit if you used a VGA cable from an Xbox 360 outputting in 480i?

    • BuckoA51 says:

      I don’t see why not. Could be an easier way to test if your setup is compatible before spending time and money tracking down other cables. That’s if Xbox doesn’t lock out 480i with the VGA cable (I can’t remember if it does or not).

  7. Andrew Kepic says:

    Is there anything else I can do to get the 580xi to convert 480i to 240p?

  8. hardyhell says:

    This Looks interesting. perhaps it will allow me to run taito x2 and naomi in a new astro City cab

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