Here's a
report from the first successful project where somebody got Megasquirt running on an SR20DET, controlling fuel and spark. Took a bit of testing, as this was the first such installation. I think he's using an
Autronic trigger disc installed in his cam sensor. Seems most SR20DET Megasquirt installations that have spark control use either the Autronic disc or EDIS. Megasquirt is not set up to work with distributorless ignitions that use different slot lengths to identify cylinders.