Pin 10 is high if you put the CDI on, no testfunttion or hall switch in.
If the CDI is running, pin 10 will be short low (56us) and Q1 will be conduct - LED will flash
BTW, there are two new Exelsheets on the website.
You don't have to calculate backwards anymore
How do I test the CDI.
[youtube]http://www.youtube.com/watch?v=PJCWWGwa9Cg[/youtube]