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Author Topic: Alternative to Jpac?  (Read 459 times)

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Alternative to Jpac?
« on: January 23, 2021, 09:01:50 pm »
Checking to see if there is an alternative to the Jpac for the protection of the video signal to an arcade monitor?
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Re: Alternative to Jpac?
« Reply #1 on: January 28, 2021, 08:48:52 pm »
see gambaman's awesome VGA-to-Scart adapter thread -,160869.0.html

I'm working on an update to the mod mentioned in post # 49 of that thread. It's double-ended now, male on one end and female on the other. Basically it takes RGBHV in, and if H-sync is running at 15Khz the green light comes on and it passes c-sync out the female end. It requires you to make the circuit board, install it between a male and female connector, and then to connect R, G & B from input to output - so if the sync is withheld you still get a scrambled video image, but it's the sync that's dangerous.

It's obviously ONLY a 15kHz video protection circuit, not a video buffer or amp (the latter being usually required by an arcade monitor) nor a keyboard/joystick encoder. If you're not into soldering i could probably sell you one once i finish making them.


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Re: Alternative to Jpac?
« Reply #2 on: January 29, 2021, 08:42:33 am »
This spinoff idea of yours (and gambaman's original scart adapter of course) has some potential I think. Well done  :applaud:

By keeping it to a simple vga in/out, there are a lot of ways to use it in cabs and other setups. Just plug in at each end.

Even without the VGA jacks, it could be used as a drop-in module for other projects.
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