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Giles Goat

hi trying to make that work using Pi3, a HDMItoVga converter, a J-Pac II interface and and Hantarex Polo 20. So far the closes I can get "I can see something" but vertically scrolling away is with :

hdmi_cvt=320 240 60 1 0 1 0
hdmi_group=2
hdmi_mode=90

If I use tvservice -m DMT I see

mode 90: 320x121 @ 59Hz 4:3, clock:25MHz x4 interlaced

I still can't get a stable image, any suggestions ? I can't find anything online that suits me.

Thanks.

@gilesgoat does the jpac ii have a video amp in there?

@ifixcoinops I think it does I can see a CY-something and a MAX4something chip. Also my bad is a standard J-PAC not J-PAC2 from Ultimarc.

@gilesgoat well so much for that theory, I just remembered some older monitors were super picky about the strength of the sync signal and vga spec is only like a volt and change

@ifixcoinops Hi, I also got a VGA666 adapter, I managed to configure it to work with a 640x480 true VGA monitor, it works so I know it works. Then I also found this place : github.com/mortaca/RGB-Pi/blob

Trying "almost all video modes" NONE seems to work, as a matter of fact I KNOW the CRT works fine because if I attach a real JAMMA card to it works lovely ! So I am wondering about the J-Pac interface now, I am quite puzzled ..

GitHubRGB-Pi/HDMI_Timings.txt at master · mortaca/RGB-PiRGB-Pi Development Repository. Contribute to mortaca/RGB-Pi development by creating an account on GitHub.

@gilesgoat what do you see, when it's nearly-but-not-quite doing the do?

@ifixcoinops It's ODD .. the image is always "running away" and looks like really LOW in intensity ( i.e. not bright enough ), I have to figure out what's going on.

@gilesgoat low brightness again points to not high enough signal voltage! Check with a meter your sync line with a real JAMMA board vs the jpac

@ifixcoinops I don't know any more "what I am debugging" .. MAYBE is the HDMI to VGA converter this time that doesn't like something ? .. I got the conclusion that the VGA666 adapter I THINK can probably NOT do "interlace" .. BUT .. HDMI SHOULD in fact I got the point that via tvservice -s it tells me "state 0xa [HDMI DMT (87) RGB full 4:3] , 512x288 @ 50.00 Hz, interlaced " which is EXACTLY what I should have .. and the monitor still displays NOTHING ! .. I am puzzled ..

@gilesgoat arcade monitors aren't interlaced, in case that's where you're going

@gilesgoat also even Euro arcade monitors were all 60hz IIRC

@ifixcoinops HUM .. let's try again then .. but then just removing the "interlace" should go .. I better find and read a manual of Hantarex Polo to see what they say about it.

@ifixcoinops I give up for the moment or I'll get INSANE ( more than what I already am ). I think the only way to maybe see/know something about would be to attach an oscilloscope and see what the heck of signals are coming out. *NOTHING* *NOTHING I TRIED* seems to please that J-Pac/Polo 20 combination. It NEVER gets right whatever signals. I though that "sure people has arcade CRTs I should find the numbers" .. NOTHING seems to work and I don't know why yet. It's incredibly frustrating !

@ifixcoinops another thing that puzzles me I tried different setting on hdmi_timings= but any time i do a tvservice -s it tells me a thing like let's say 320x240 @60 Hz progressive .. it seems that no matter what I can't make it say "interlaced" and one of the params of hdmi_timings should be "interlaced/progressive" .. it's puzzling !