On Fri, 25 Oct 2013, Tony Duell wrote:
card, comes up
through a resistor, goes to the light-pen header, through another
Are you sure
it's the light pen header? The IBM CGA card has 2 header
plugs on it, one fo the a light pen, the other for a modulator. The
composite signal goes ot the latter.
yep
6 pin for light pen
4 pin for composite out