This port applies to the Japanese and US Duo systems, as well as the CoreGrafx and PC-Engine consoles, the Super CD-ROM system, SuperGrafx console and the LT. Sorry boys and girls - there is no S-video or RGB output from the Duo's port. You can tap RGB internally, and using a commercial adaptor convert the RGB to S-video, but it gets expensive at this point. Thanks to Shou-Sama for finding the pinout which I lost.
Looking at console
Pin
Assignment
1
Video
2
Right
3
Ground
4
+5v
5
Left
All contents (c)1999 Game Station
X unless otherwise noted. All trademarks copyright of their respective
companies. Game Station X assumes absolutely no responsiblility whatsoever
for any sort of damages incurred while either viewing this information
or doing anything with said information. If you don't like it, change the
channel. Some of this information may have come from other sources, and Game Station
X in no way implies ownership of this information,
and merely intends to provide a convenient source for finding this information.
That said, we wrote this, and would appreciate your not lifting it for your
own page without due credit. Mail us!