CD32 with 8 Pin Mini Din - RGB Scart Possible?

[wmsteele]

I have a CD32 that has an 8 pin connector where you would normally find a 4 pin S-Video port so potentually could be a French SECAM version, it has with a rev 4 motherboard but also a modulator for RF output. According to what I've been able to uncover the French CD32 didn't have RF output, so its a bit odd, although this would appear to be the only CD32 board with an 8 pin connector.

The board has been recapped and the modulator removed. The challenge is to now make a suitable RGB scart cable, unfortunately I've not been successful, all I'm getting is a black screen. Some sort of signal is present as the TV would normally show "no connection" but when the CD32 is powered this disappears but screen remains black/blank. The board is otherwise perfect, RGB output works fine using Kipper's adapter.

The rev 4 schematics (SECAM version) suggest the socket should support RGB output suitable for connection to a SCART socket...


So... 1 = Red, 2 = Blue, 3 = GND, 4 = Green, 5 = GND, 6 = Luma, 7 = C-Sync, 8 = Chroma

DIN = to = Scart
1 = Red = 15
2 = Blue = 7
3 = GND = 17 and or 18
4 = Green = 11
5 = GND = 17 and or 18, or leave blank
6 = Luma = leave empty (important only for S-Video)
7 = C-Sync = 20
8 = Chroma = leave empty (important only for S-Video)

Have I missed anything?

 

[8bitplus]

Are you sure the extra pins on the port are connected?
Perhaps its just wired for s-video Lum and Chrom....

 

[wmsteele]

According to the specs they are fully wired as shown. Would it be possible to confirm by looking at the board?? Will post some pics.

 

[8bitplus]

I cannot see how that port can be wired for RGB.

http://cd32.amiga32.com/tech/cd32-video.png

- - - Updated - - -

According to the specs they are fully wired as shown. Would it be possible to confirm by looking at the board?? Will post some pics.

Yes, Some photos would help. Also photo from under the port with soldering.

 

[wmsteele]

Thats not a revision 4 motherboard schematic!

Rev 3 and lower all look like your link, you need to review a rev 4 schematic, as per my screen grab above!

Schematic are available here... http://http://www.amigawiki.de/doku.php?id=en:service:schematics

 

[8bitplus]

I still think although the French version 4 had a 8-pin DIN, it was still wired for s-video and not RGB. I could be wrong, but if you can trace the extra pins back to the video chip then it might be possible.

 

[wmsteele]

I'm 99.99% sure... its listed on the schematics as a 'RGB/S-Video'

I've also found various posts of people successfully taping a RGB signal from these boards.

Maybe some pictures would help, will get some uploaded this evening.

 

[8bitplus]

No need for the pics, I think your right. I found the diagrams on Ian Stedman's page and it looks RGB to me.
http://www.ianstedman.co.uk/downloads/CD32_V4_Schematics.pdf

So it might be a signal issue. Have you tried another TV? it might not like the voltage levels..

 

[wmsteele]

Some clues...

1. Click... from Amiga Impact (Google Translate French to English)
2. Click... from Classic Gamers (Google Translate German to English)

 

[a.mi.goun]

Do you use resistor on C-Sync in your cable? TV might also miss voltage on pin 16 to select RGB mode..

 

[wmsteele]

Thanks for the suggestions, what size of resistor would the C-Sync connection need? None of the docs I've looked at mention a resistor here, worth a try?

The German guide differs with these...
6 = Luma = 20 (Video-Eingang)
7 = C-Sync = 16 (Austastung RGB)
8 = Chroma = 8 (AV-Umschaltung)

Would connecting C-Sync to scart 16 supply the required voltage?
Is using Luma to scart 20 a viable sync option?

I was under the impression Luma & Chroma were only needed for S-Video?

Still trying to get my head around the correct DIN to SCART connections, I've found various combos now... confused!

 

[wmsteele]

Success :-D

Perfect RGB picture from 8 pin mini DIN to SCART, wired as follows...

8 7 6
5 4 3
2 1

[TABLE="width: 500"]
[TR]
[TD]DIN
[/TD]
[TD]SCART
[/TD]
[TD]Wire colour as pictured
[/TD]
[/TR]
[TR]
[TD]1 = Red[/TD]
[TD]15 = Red[/TD]
[TD] Red[/TD]
[/TR]
[TR]
[TD]2 = Blue[/TD]
[TD]7 = Blue[/TD]
[TD]Blue[/TD]
[/TR]
[TR]
[TD]3 = GND[/TD]
[TD]--[/TD]
[TD]--[/TD]
[/TR]
[TR]
[TD]4 = Green[/TD]
[TD]11 = Green[/TD]
[TD]Green[/TD]
[/TR]
[TR]
[TD]5 = GND[/TD]
[TD]18 = RGB Blanking Ground[/TD]
[TD]White[/TD]
[/TR]
[TR]
[TD]6 = Luma[/TD]
[TD]20 = Composit Sync[/TD]
[TD]Black[/TD]
[/TR]
[TR]
[TD]7 = C-Sync[/TD]
[TD]16 = RGB Blanking[/TD]
[TD]Yellow[/TD]
[/TR]
[TR]
[TD]8 = Chroma[/TD]
[TD]--[/TD]
[TD]--[/TD]
[/TR]
[/TABLE]