Zac67 wrote:
The CV's scan doubler is actually just a (clever) way to pipe the RGB output into the VESA feature connector of the S3 chip and then use a digital overlay to show it through the VGA output.
Nope.
The CV3D outputs a VGA signal to the pin header you plug the SD's flat cable into.
The SD is a normal standalone scandoubler with an added video switcher.. The switcher is controlled by a signal from the CV3D, via the same header connector.
When you have a CV3D+SD combo, the monitor cable is plugged into the SD, not the CV3D.
BTW, feature connectors in ancient SVGA boards normally only allow direct access to the video RAM on the card.
