H-Scrolling Problem (Cadet only)

Helpdesk
1

I have a little problem with one of my Cadets.
I plugged in my SNES to the Cadet III, thru to the Cadet I and Luma into the Cadet II.

Each color input displays the appropriate color but the video scrolls horizontally. Vertical is locked perfectly, but when I disconnect the sync input to Cadet I, the video will scroll vertically too. Reconnecting the sync input to Cadet I will lock vertical again. I of course have the 14-pin connected and I can see the signals on each pin. I also looked at the video output from the Cadet II on my scope and it appears to be fine. I can see both vertical and horizontal sync, and color burst. I didn’t scope the output with a video source yet.

I can snap some photos if needed but in the meantime can anyone think of where the problem could lie?

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It’s because the SNES is 240p and only 480i is currently supported.

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Yep, that was it! I plugged in my Wii and it works as expected. My PSU is noisy, but I’ll be sorting that out later.
I really wish the Cadet I switch was for 240p/480i instead of region. I guess I’ll buy an upscaler at some point.

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I was about to suggest we could create a Cadet N Snes 240p to 480i upscaler 4HP module & then thought of all the deep 1U Scaler rack models out there in the world.
On the other hand, it may be possible. I’m proving I really know next to nothing of electronic engineering but if the Cadet 1, 2 & 3 can do what they do, surely an upscaler from 240p to 480i is possible.
What part of the combined Cadet 1 to 3 circuit creates the 480i size? There’s the preprogrammed Ata-Meg 20pin IC & the smaller pre-soldered SMT IC on the Cadet 3 (is it an AD724JRZ?). I don’t have the Cadet 2 but can look at the schematic, it is the output of the combo so I could imagine the output scale created there.

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A scaler with YUV output, and a YUV to RGB module might be an option to consider- then you’ll have full colour at 480i

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Cadet I creates the sync signal which is really what restricts it to 480i. The main problem is the order at which the lines arrive from the SNES. 240 to 480 seems straightforward, but the main difference is between the “I” and “P.”
I’ll look into what it would take to make a scaler module. It’s definitely gonna require a dedicated IC to act as a frame buffer, most likely in SMT. But I’ll try to find out more soon.

Hm, indeed. I do have a YUV to RGB module (which I need to test). My biggest concern is the cost of an upscaler. I honestly haven’t looked at any yet.
Prefereably, I like to have full “color” at 480i. :wink:

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