15kHz Video Converter


I have a Xerox 820 (circa 1984) main board and power supply, but no CRT. For testing purposes, I would like to convert the 15 KHz video output to VGA. There are arcade video converters that can convert composite video to VGA, so if I could convert the 820 video output to composite, that could be a solution. I was wondering is anyone has done this sort of video conversion or has any advice or tips on how to do this.


You might just try it. I haven’t looked to see exactly what the 820 uses, but many 15 kHz video outputs are essentially just very high bandwidth composite video (sometimes with chrome and luma separation a la S-video, for color signals). A 'scope would answer that pretty quickly (if it looks like composite, it probably is!). If that’s the case, you’ll probably get a display you can at least view, although it may be blurry or have color artifacts. (An Apple ][ 80-column display (preferably on a B&W monitor) is difficult to read but not unusable, for example.)

I used to have a Xerox 16/8, which iinm is the 820 with an expansion box. I want to say the resolution was somewhat better then CGA, I don’t recall the text being as grainy. I can’t swear by this though. But if I’m right, an easier solution migjt be to source an IBM 5151, 5154 (probably expensive). Or any monitor that can handle 350 - 400 lines of resolution (vertical of course). And giggle some controls until the image LOOKS A REALLY NICE. That is assuming the video is seperate ttl signals. Honestly I don’t have specifics.

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