The way I see it the negative distributor terminal connects to the distributor. Inside the distributor either points or an electronic module open and close the negative side of the coil to ground. I would think all I have to do is switch the tach input to the megasquirt on and off to ground. Maybe "pulse" isn't the correct nomenclature for what I'm looking for.
I was also wrong on the number of pulses necessary. For some reason I was thinking one pulse every other crank revolution, but in reality, for an 8 cylinder application there would be 4 pulses every revolution of the crank. So in order to fake the megasquirt into operating at up to 10K RPM I need to generate up to 40K pulses per minute.
So I need a device that will switch the tach input to the megasquirt on and off to ground at a rate variable between 2000 and 40K times per minute. Thanks for the help.
Dustin