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DrMike

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Hello everbody, hope for some help.
The setup is as follows:
* Retropie
* HDMI -> VGA
* VGA -> RGB
And I want to try to keep the CRT screen.
Is this possible? I get the screen lit up with a lot of noise, but nothing more.

I bought a GBS 8100, but my screen has a different type of connector.
segacontact.jpg

In Sega Arcade I have found the following cables I think are for the picture.
View attachment 26733
Blue/white - gnd
White - Sync
Red - Rgb
Gren - rGb
Blue - rgB

GBS 8100
rgb.jpg
Blue - RGB
Gren - RGB
White - RGB
Black - GND
Red - Sync

Is it possible to connect like this?
 

Attachments

  • contact1.jpg
    contact1.jpg
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I don't own one, but just looking from the manual the GBS8100 outputs VGA resolution, 31khz. That won't work with your monitor as it's dual res only (15khz, 24khz.)

Anyway, it doesn't matter, because you don't need it. You can output 15khz straight from the Pi. Much better than trying to downscale a high resolution signal.

https://www.retrorgb.com/rpi240p.html

Remember to switch your monitor to 15khz as most likely it isn't auto-sync. You have to switch a connector from 'HIGH' to 'LOW' on the chassis.
 
Also are you trying to emulate a Sega Model 2 on a Pi? I didnt know there were any optimised emulators for that system on Pi.
 
Thanks for the feedback.
I feel I have to explain better what to do.
I've got a SEGA Arcade cabinet.
What I'm going to do is turn it into a MAME / Retropi / Raspberry pie cabinet.
I will remove all electronics and save buttons, joysticks and original CRT monitor.
-
But I can't convert HDMI-> VGA-> CGA / RGB then conncet to SEGA monitor.
Something goes wrong with the signal.
 
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One more thing, I don't think there's any Jamma connection in my Arcade?
 
Model 2 used custom filter board and so didnt have a JAMMA harness afaik.

Look at nem's reply - the reason your video is not displaying correctly is that your GBS 8100 is outputting 31khz something that your monitor doesnt support.
 
OK, I admit, I was wrong. I think I was reading a manual for the 8220 :/ . Anyway, I found the actual manual for the thing and it should output 480i from the RGBS connector:

https://www.hollandcomputers.com/da...-vga-rgb-converter vga to cga instruction.pdf (page 3)

Swap the chassis from 'HIGH' / 'HI' (24khz) to 'LOW' (15khz), and wire red, green, blue, sync and ground to the input connector on the chassis. It's going to look like ass, but if you're happy with it, then that's all that matters.
 
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I'm really confused now ...
 
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Neither your GBS or your Pi will output 24khz.

I took a pic of a MS8-26. It should be pretty close to whatever chassis you have:


ms8_high_low.jpg


Swap the connector from HIGH to LOW for 15khz.
 
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